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Enzymatic reactionDetermination of the cytotoxicity after contact of the test element. The assay is based on the ability of viable cells to incorporate and bind the supravital neutral red dye in the lysosomes.Early stage fertile hens eggs are used to determine if a substance is a severe ocular irritant or corrosive. Effects are measured by the onset of (1) hemorrhage; (2) coagulation; and (3) vessel lysis.Because early stage eggs are used this test is considered a non-animal test. Semi-quantitative assessment of the cytotoxicity (loss of viable cells) due to a test product after diffusion on agarose gel in contact with a fibroblasts monolayer. MTT, a yellow tetrazole dye that is reduced to an insoluble purple formazan product by the mitochondria of living cells, is used to evaluate cells viability.Assessment of the ability of a test chemical to induce cytotoxicity in a RhCE tissue. Tissue viability is measured by enzymatic conversion of the vital dye MTT by the viable cells of the tissue into a blue MTT formazan salt. Assessment of the ability of a test chemical to induce cytotoxicity in a RhCE tissue. Tissue viability is measured by enzymatic conversion of the vital dye MTT by the viable cells of the tissue into a blue MTT formazan salt. The method provides a UV spectral absorbance curve from which the UVA Protection Factor (UVA-PF) is determined.Test on reconstructed human epidermis (RHE). The cellular viability is measured by the the enzymatic change of the MTT colorant in the blue Formazan salt, measured after the tissue extraction.An adequate substrate on which the product has been spread is used. Measures are made by means of a spectrophotometric method.A UV spectral absorbance curve allows us to determine the Critical Wavelength (CW).This test is based upon an in vitro spectrophotometric measurement technique. After that, the product may be labeled as «Broad Spectrum» with SPF value on the front label.The level of photostability is measured from the collective effectiveness of UVA and UVB before and after UV exposure. This method consists in evaluating the IR protection levels expressed by the IR-CW (UV/VIS/IR balance) and the % IR (percentage of intensity of IR protection) from a sunscreen product through the full spectrum (from 290 nm to 2500 nm) measured by means of a spectrophotometric methodThis method consists in evaluating the Blue Light protection levels expressed by the BL-CW (UV/VIS balance) and the % BL (percentage of intensity of BL protection) from a sunscreen product through the spectrum (from 290 nm to 500 nm) measured by means of a spectrophotometric method. The method consists in assessing the Sun Protection Factor (SPF) before and after water immersion. The method consists in assessing the Sun Protection Factor (SPF) before and after double water immersions.Realisation of an automated textile rubbing on surface substrates with a controled pressure, speed and time. This method is based on the comparison of the Sun Protection Factor (SPF) on a dry then a wet substrate and the calculation of Wet Skin percentage. A spectrophotometric method, if the sunscreen product preserves its UV protection in extreme conditions.An adequate substrate on which the product has been spread is used. Measures are made by means of a spectrophotometric method.The method is based upon an in vitro spectrophotometric measurement technique in which the tested product is spread using adequate substrate.A test product is put in contact with calves’ corneas. The measurement of the opacity and permeability of the corneas to fluorescein is used to evaluate the corneal damage and, therefore, the irritant potential of the test product.The test substance is applied on the cornea of an enucleated chicken eye’s. Toxic effects to the cornea are measured through several parameters.The test substance is put in contact with a confluent monolayer of Statens Seruminstitut Rabbit Cornea (SIRC) cells. After five minutes, cytotoxicity is measured.to be completedThe test product is put in contact with a water-insoluble protein, zein protein, obtained from yellow corn, that is similar to keratin present in the skin and hair. Zein protein solubilization (= denaturation) gives information about the test product : the irritation potential of the product is directly proportional to the quantity of dissolved (denaturated) proteins.The test material (solid or liquid) is applied uniformly and topically to a three-dimensional human skin model. Corrosive materials are identified by their ability to produce a decrease in cell viability below defined threshold levels at specified exposure periods. https://www.oecd-ilibrary.org/fr/environment/test-no-431-in-vitro-skin-corrosion-human-skin-model-test_9789264071148-enThis method evaluate photo-cytotoxicity by the relative reduction in viability of cells exposed to the chemical in the presence versus absence of light. Cytotoxicity in this test is expressed as a concentration-dependent reduction of the uptake of the Vital dye Neutral Red (NR) when measured 24 hours after treatment with the test chemical and irradiation. https://www.oecd-ilibrary.org/fr/environment/test-no-432-in-vitro-3t3-nru-phototoxicity-test_9789264071162-enThe acute toxic response is defined after the first exposure of the reconstructed skin model to certain chemicals and subsequent exposure to light. The DPRA is proposed to address the molecular initiating event leading to the skin sensitisation, namely protein reactivity, by quantifying the reactivity of test chemicals towards model synthetic peptides containing either lysine or cysteine. https://www.oecd-ilibrary.org/fr/environment/test-no-442c-in-chemico-skin-sensitisation_9789264229709-enOECD 442D describes 2 test methods allowing the discrimination between skin sensitisers and non-sensitisers by assessing keratinocyte activation under test chemical application. KeratinoSens™ test method uses an immortalised adherent cell line derived from human keratinocytes which stably harbours a luciferase reporter gene under the control of the antioxidant response element (ARE) of the human AKR1C2 gene known to be up-regulated by skin sensitisers via the nuclear factor Nrf2. The principle of the LuSens test method is similar but uses the ARE of the rat NQO1 gene known to be up-regulated by contact sensitisers. In both cases, the luciferase signal intensity reflects the level of keratinocyte activation by sensitisers. These test methods either quantify the change in the expression of cell surface marker(s) associated with the process of activation of monocytes and DC following exposure to sensitisers (e.g. CD54, CD86) or the changes in IL-8 expression, a cytokine associated with the activation of DC. https://www.oecd-ilibrary.org/fr/environment/test-no-442e-in-vitro-skin-sensitisation_9789264264359-enQuantitatively measurement quantitatively the over expression of 62 specific biomarkers of skin sensitization and irritation by RT-PCRSuspensions of bacterial cells are exposed to the test substance in the presence and in the absence of an exogenous metabolic activation system. The principle of this test is that it detects mutations which revert mutations present in the test strains and restore the functional capability of the bacteria to synthesize an essential amino acid. The revertant bacteria are detected by their ability to grow in the absence of the amino acid required by the parent test strain. This method allows the detection of base substitution or frame-shifting point mutations. The assay detects the activity of clastogenic and aneugenic test substances in cells that have undergone cell division during or after exposure to the test substance.Cytotoxicity is determined by measuring the relative cloning efficiency (survival) or relative total growth of the cultures after the treatment period. Tests Using the Thymidine Kinase Gene.Purpose : identify agents that cause structural chromosome aberrations (chromosome or chromatid aberrations) in cultured mammalian somatic cells. Cell cultures are exposed to at least three concentrations of the test substance. At predetermined intervals after exposure, metaphase cells are analysed microscopically for the presence of chromosome aberrations. Caspase-14 is a protease initially expressed in the suprabasal layers of the epidermis in an inactive form and then converted into an active form essentially present in the stratum corneum. It is involved in the terminal differentiation of keratinocytes and thus the establishment of the skin barrier, but also in the filaggrin proteolysis and the formation of NMF (Natural Moisturizing Factor) allowing the hydration and thus the functionality of the skin barrier as well as in the protection of the skin against UVB. Caspase-14 is a protease initially expressed in the suprabasal layers of the epidermis in an inactive form and then converted into an active form essentially present in the stratum corneum. It is involved in the terminal differentiation of keratinocytes and thus the establishment of the skin barrier, but also in the filaggrin proteolysis and the formation of NMF (Natural Moisturizing Factor) allowing the hydration and thus the functionality of the skin barrier as well as in the protection of the skin against UVB. Caspase-14 is a protease initially expressed in the suprabasal layers of the epidermis in an inactive form and then converted into an active form essentially present in the stratum corneum. It is involved in the terminal differentiation of keratinocytes and thus the establishment of the skin barrier, but also in the filaggrin proteolysis and the formation of NMF (Natural Moisturizing Factor) allowing the hydration and thus the functionality of the skin barrier as well as in the protection of the skin against UVB. Claudin 1 (CLDN-1) and 4 (CLDN-4) are transmembrane proteins constituting the tight junctions which maintain the keratinocytes closely associated in the epidermis. A decrease of Claudin level beyond a threshold may alter skin barrier function and induce skin inflammation. This has been observed in some atopic dermatitis cases. Claudin 1 (CLDN-1) and 4 (CLDN-4) are transmembrane proteins constituting the tight junctions which maintain the keratinocytes closely associated in the epidermis. A decrease of Claudin level beyond a threshold may alter skin barrier function and induce skin inflammation. This has been observed in some atopic dermatitis cases. Corneodesmosin is a protein secreted by granular keratinocytes via the lamellar bodies and incorporated into desmosomes shortly before their transformation into corneodesmosomes. Corneodesmosin displays adhesive properties by acting like a Velcro and is therefore involved in skin barrier function. Moreover, corneodesmosin is then sequentially proteolyzed as corneocytes migrate towards the skin surface, thus allowing appropriate desquamation and skin barrier renewal. to be completedto be completedClaudin 1 (CLDN-1) and 4 (CLDN-4) are transmembrane proteins constituting the tight junctions which maintain the keratinocytes closely associated in the epidermis. A decrease of Claudin level beyond a threshold may alter skin barrier function and induce skin inflammation. This has been observed in some atopic dermatitis cases. to be completedE-Cadherin is a protein belonging to adherens junctions that allow cell-cell adhesion. Its adhesive activity is also crucial for the assembly of other junctional complexes such as tight junctions and involved in the polarity of the keratinocytes and the epidermis. E-adherin is therefore crucial for the establishment of the skin barrier. to be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Filaggrin is a marker of the keratinocyte terminal differentiation. It derives from the cleavage of profilaggrin, a protein synthesised in granular keratinocytes, and associates with keratins inside the corneocytes to form, with other proteins, a resistant protein assembly which characterises the stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin also produces a mixture of amino acids constituting the NMF (Natural Moisturizing Factor) and thus participates in the hydration of the skin which is also involved in the barrier function.Filaggrin is a marker of the keratinocyte terminal differentiation. It derives from the cleavage of profilaggrin, a protein synthesised in granular keratinocytes, and associates with keratins inside the corneocytes to form, with other proteins, a resistant protein assembly which characterises the stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin also produces a mixture of amino acids constituting the NMF (Natural Moisturizing Factor) and thus participates in the hydration of the skin which is also involved in the barrier function.Filaggrin is a marker of the keratinocyte terminal differentiation. It derives from the cleavage of profilaggrin, a protein synthesised in granular keratinocytes, and associates with keratins inside the corneocytes to form, with other proteins, a resistant protein assembly which characterises the stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin also produces a mixture of amino acids constituting the NMF (Natural Moisturizing Factor) and thus participates in the hydration of the skin which is also involved in the barrier function.Filaggrin is a marker of the keratinocyte terminal differentiation. It derives from the cleavage of profilaggrin, a protein synthesised in granular keratinocytes, and associates with keratins inside the corneocytes to form, with other proteins, a resistant protein assembly which characterises the stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin also produces a mixture of amino acids constituting the NMF (Natural Moisturizing Factor) and thus participates in the hydration of the skin which is also involved in the barrier function. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.to be completedInvolucrin is a protein whose synthesis is stimulated by an increase in intracellular calcium level. Produced in the cytoplasm of stratum granulosum keratinocytes, it is involved in the initiation of horny envelope formation where its crosslinking with envoplakin / peripakin dimers is allowed by transglutaminase 1. It is therefore a marker of terminal differentiation and plays a major role in skin barrier function. to be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Laminin 332 (previously called Laminin V) is an essential component of the dermal-epidermal junction. It allows epidermal attachment and modulates the differentiation of epidermal stem cells. Thus, Laminin 332 synthesis may modulate the skin barrier integrity and its function.Laminin 332 (previously called Laminin V) is an essential component of the dermal-epidermal junction. It allows epidermal attachment and modulates the differentiation of epidermal stem cells. Thus, Laminin 332 synthesis may modulate the skin barrier integrity and its function.Laminin 332 (previously called Laminin V) is an essential component of the dermal-epidermal junction. It allows epidermal attachment and modulates the differentiation of epidermal stem cells. Thus, Laminin 332 synthesis may modulate the skin barrier integrity and its function.Loricrin is an insoluble protein that is synthesised and stored as granules in the keratinocytes of the stratum granulosum. It then enters the composition of the stratum corneum where it is linked by covalent bonds to other proteins by transglutaminases. As a major component of the stratum corneum, it represents a marker of the terminal differentiation of the epidermis and plays an essential role in the skin barrier function. Loricrin is an insoluble protein that is synthesised and stored as granules in the keratinocytes of the stratum granulosum. It then enters the composition of the stratum corneum where it is linked by covalent bonds to other proteins by transglutaminases. As a major component of the stratum corneum, it represents a marker of the terminal differentiation of the epidermis and plays an essential role in the skin barrier function. Loricrin is an insoluble protein that is synthesised and stored as granules in the keratinocytes of the stratum granulosum. It then enters the composition of the stratum corneum where it is linked by covalent bonds to other proteins by transglutaminases. As a major component of the stratum corneum, it represents a marker of the terminal differentiation of the epidermis and plays an essential role in the skin barrier function. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Loricrin is an insoluble protein that is synthesised and stored as granules in the keratinocytes of the stratum granulosum. It then enters the composition of the stratum corneum where it is linked by covalent bonds to other proteins by transglutaminases. As a major component of the stratum corneum, it represents a marker of the terminal differentiation of the epidermis and plays an essential role in the skin barrier function. to be completedOccludin is a transmembrane protein located at the tight junctions (TJs) of the granular layer. It is therefore a marker of keratinocyte differentiation and plays a role in skin barrier function. It also plays a role in the regeneration of the epidermis. A defect in the expression or distribution of this protein can lead to an alteration of the skin barrier.to be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.to be completedPeriplakin (PPL) is a small protein which expression increases during keratinocyte differentiation. With envoplakin [ENV], it connects intermediate filaments (including cytokeratins) to membrane and cellular junctions. Thus, it is involved in the assembly of the cornified envelope and therefore skin barrier formation.to be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Psoriasin (S100A7) is an antimicrobial peptide produced by keratinocytes which limits the development of pathogenic microorganisms. It is also involved in various processes including skin inflammation and keratinocyte differentiation. A modulation of its expression (e.g. psoriasis) affects the composition of the skin microbiota and may alter epidermal differentiation and thus the skin barrier. Psoriasin (S100A7) is an antimicrobial peptide produced by keratinocytes which limits the development of pathogenic microorganisms. It is also involved in various processes including skin inflammation and keratinocyte differentiation. A modulation of its expression (e.g. psoriasis) affects the composition of the skin microbiota and may alter epidermal differentiation and thus the skin barrier. Psoriasin (S100A7) is an antimicrobial peptide produced by keratinocytes which limits the development of pathogenic microorganisms. It is also involved in various processes including skin inflammation and keratinocyte differentiation. A modulation of its expression (e.g. psoriasis) affects the composition of the skin microbiota and may alter epidermal differentiation and thus the skin barrier. Psoriasin (S100A7) is an antimicrobial peptide produced by keratinocytes which limits the development of pathogenic microorganisms. It is also involved in various processes including skin inflammation and keratinocyte differentiation. A modulation of its expression (e.g. psoriasis) affects the composition of the skin microbiota and may alter epidermal differentiation and thus the skin barrier. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. In Atopic Dermatitis (AD), its expression is decreased, inducing a more fragile skin barrier. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. In Atopic Dermatitis (AD), its expression is decreased, inducing a more fragile skin barrier. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. In Atopic Dermatitis (AD), its expression is decreased, inducing a more fragile skin barrier. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. In Atopic Dermatitis (AD), its expression is decreased, inducing a more fragile skin barrier. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.to be completedTransglutaminase (TGM) is a calcium-dependent enzyme catalyzing an intermolecular isopeptide bond formation between proteins. 9 TGMs have been identified in human. Among them, TGM 1, 3 and 5 are known to participate in the covalent cross-linking of constitutive proteins such as loricrin and involucrin ioccuring during the cornification process. Thus, TGMs are required for skin barrier function. to be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.α6β4 integrins are transmembrane proteins playing a key role in the formation and stabilization of junctional adhesion complexes called hemidesmosomes. They are connected to the intermediate filament system of basal keratinocytes and the laminin 332 of the dermal-epidermal junction. They are also involved in the regulation of a variety of signaling processes allowing for example keratinocyte migration. A defect in the expression of those molecules may therefore impair skin integrity and barrier function. to be completedPerlecan is a heparan sulfate proteoglycan. Basal keratinocytes produce Perlecan which is accumulated at the dermal epidermal junction (DEJ) level while Perlecan coming from fibroblasts is accumulated in the dermal extracellular matrix. At the DEJ level, Perlecan allows to maintain the self-renewal capacities of keratinocytes and is involved in keratinocyte survival and differentiation. A decrease of Perlecan, which occurs for example during skin aging, may therefore induce an alteration of skin barrier integrity. to be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Langerin (CD207) is a C-type lectin receptor expressed on Langerhans cells and a specific population of dermal dendritic cells. It may therefore be used as a marker of those cells. It is also directly involved in specific processes such as the skin induced tolerance to protein antigens. Langerin (CD207) is a C-type lectin receptor expressed on Langerhans cells and a specific population of dermal dendritic cells. It may therefore be used as a marker of those cells. It is also directly involved in specific processes such as the skin induced tolerance to protein antigens. Langerin (CD207) is a C-type lectin receptor expressed on Langerhans cells and a specific population of dermal dendritic cells. It may therefore be used as a marker of those cells. It is also directly involved in specific processes such as the skin induced tolerance to protein antigens. Langerin (CD207) is a C-type lectin receptor expressed on Langerhans cells and a specific population of dermal dendritic cells. It may therefore be used as a marker of those cells. It is also directly involved in specific processes such as the skin induced tolerance to protein antigens. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Skin contains at least 20 matrix metalloproteinase (MMP) which degrade extracellular matrix (ECM) component under normal circumstances and thus allow ECM remodelling. A high MMP level has also been correlated with various skin inflammatory diseases as some peptides released by the activity of some MMPs (including MMP-2, MMP-9 or MMP-12) and called matrikines are able to induce inflammatory processes. Skin contains at least 20 matrix metalloproteinase (MMP) which degrade extracellular matrix (ECM) component under normal circumstances and thus allow ECM remodelling. A high MMP level has also been correlated with various skin inflammatory diseases as some peptides released by the activity of some MMPs (including MMP-2, MMP-9 or MMP-12) and called matrikines are able to induce inflammatory processes. Skin contains at least 20 matrix metalloproteinase (MMP) which degrade extracellular matrix (ECM) component under normal circumstances and thus allow ECM remodelling. A high MMP level has also been correlated with various skin inflammatory diseases as some peptides released by the activity of some MMPs (including MMP-2, MMP-9 or MMP-12) and called matrikines are able to induce inflammatory processes. Skin contains at least 20 matrix metalloproteinase (MMP) which degrade extracellular matrix (ECM) component under normal circumstances and thus allow ECM remodelling. A high MMP level has also been correlated with various skin inflammatory diseases as some peptides released by the activity of some MMPs (including MMP-2, MMP-9 or MMP-12) and called matrikines are able to induce inflammatory processes. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Psoriasin (S100A7), is an antimicrobial peptide expressed by keratinocytes and involved in many functions including wound healing, cell proliferation, differentiation, apoptosis, but also immune responses with cytokine/chemokine production, neutrophile migration and inflammation. Expressed at a low level in healthy skin, psoriasin is overexpressed in some tumors and inflammatory diseases such a psoriasis.Psoriasin (S100A7), is an antimicrobial peptide expressed by keratinocytes and involved in many functions including wound healing, cell proliferation, differentiation, apoptosis, but also immune responses with cytokine/chemokine production, neutrophile migration and inflammation. Expressed at a low level in healthy skin, psoriasin is overexpressed in some tumors and inflammatory diseases such a psoriasis.Psoriasin (S100A7), is an antimicrobial peptide expressed by keratinocytes and involved in many functions including wound healing, cell proliferation, differentiation, apoptosis, but also immune responses with cytokine/chemokine production, neutrophile migration and inflammation. Expressed at a low level in healthy skin, psoriasin is overexpressed in some tumors and inflammatory diseases such a psoriasis.Psoriasin (S100A7), is an antimicrobial peptide expressed by keratinocytes and involved in many functions including wound healing, cell proliferation, differentiation, apoptosis, but also immune responses with cytokine/chemokine production, neutrophile migration and inflammation. Expressed at a low level in healthy skin, psoriasin is overexpressed in some tumors and inflammatory diseases such a psoriasis. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Constantly released by keratinocytes, the human ribonuclease RNase 7 accumulates on the skin surface. Its expression can be induced by cytokines, growth factors or microbial factors and it has been found at a high level in cutaneous inflammatory diseases such as psoriasis or atopic dermatitis. It exhibits a potent antimicrobial activity against various microorganisms including bacteria and virus, thus controlling skin microbiota composition. RNase 7 also exerts immunomodulatory activities. Constantly released by keratinocytes, the human ribonuclease RNase 7 accumulates on the skin surface. Its expression can be induced by cytokines, growth factors or microbial factors and it has been found at a high level in cutaneous inflammatory diseases such as psoriasis or atopic dermatitis. It exhibits a potent antimicrobial activity against various microorganisms including bacteria and virus, thus controlling skin microbiota composition. RNase 7 also exerts immunomodulatory activities. Constantly released by keratinocytes, the human ribonuclease RNase 7 accumulates on the skin surface. Its expression can be induced by cytokines, growth factors or microbial factors and it has been found at a high level in cutaneous inflammatory diseases such as psoriasis or atopic dermatitis. It exhibits a potent antimicrobial activity against various microorganisms including bacteria and virus, thus controlling skin microbiota composition. RNase 7 also exerts immunomodulatory activities. Constantly released by keratinocytes, the human ribonuclease RNase 7 accumulates on the skin surface. Its expression can be induced by cytokines, growth factors or microbial factors and it has been found at a high level in cutaneous inflammatory diseases such as psoriasis or atopic dermatitis. It exhibits a potent antimicrobial activity against various microorganisms including bacteria and virus, thus controlling skin microbiota composition. RNase 7 also exerts immunomodulatory activities. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification avoiding the development of inflammatory diseases such as atopic dermatitis. Moreover, it is required for the production of many cytokines and the recruitment of macrophages, neutrophils and mast cells. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification avoiding the development of inflammatory diseases such as atopic dermatitis. Moreover, it is required for the production of many cytokines and the recruitment of macrophages, neutrophils and mast cells. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification avoiding the development of inflammatory diseases such as atopic dermatitis. Moreover, it is required for the production of many cytokines and the recruitment of macrophages, neutrophils and mast cells. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification avoiding the development of inflammatory diseases such as atopic dermatitis. Moreover, it is required for the production of many cytokines and the recruitment of macrophages, neutrophils and mast cells. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Decorin is a key extracellular matrix component playing a role in fibrotic disorders, in cancer cancer as it present antitumor, antimetastatic and antiangiogenic properties, but also in inflammation as it can stimulate pro-inflammatory cytokines such as TNFalpha or IL-6. Initially identified as a natural inhibitor of TGF-β, soluble decorin is also able to target EGFR, IGF-IR, VEGFR2, and PDGFR, thus modulating various signaling pathways and inducing caveosomal internalization and receptor degradation. Decorin is a key extracellular matrix component playing a role in fibrotic disorders, in cancer cancer as it present antitumor, antimetastatic and antiangiogenic properties, but also in inflammation as it can stimulate pro-inflammatory cytokines such as TNFalpha or IL-6. Initially identified as a natural inhibitor of TGF-β, soluble decorin is also able to target EGFR, IGF-IR, VEGFR2, and PDGFR, thus modulating various signaling pathways and inducing caveosomal internalization and receptor degradation. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Decorin is a key extracellular matrix component playing a role in fibrotic disorders, in cancer cancer as it present antitumor, antimetastatic and antiangiogenic properties, but also in inflammation as it can stimulate pro-inflammatory cytokines such as TNFalpha or IL-6. Initially identified as a natural inhibitor of TGF-β, soluble decorin is also able to target EGFR, IGF-IR, VEGFR2, and PDGFR, thus modulating various signaling pathways and inducing caveosomal internalization and receptor degradation.Decorin is a key extracellular matrix component playing a role in fibrotic disorders, in cancer cancer as it present antitumor, antimetastatic and antiangiogenic properties, but also in inflammation as it can stimulate pro-inflammatory cytokines such as TNFalpha or IL-6. Initially identified as a natural inhibitor of TGF-β, soluble decorin is also able to target EGFR, IGF-IR, VEGFR2, and PDGFR, thus modulating various signaling pathways and inducing caveosomal internalization and receptor degradation. LL37 / hCAP18 is the single known human cathelicidin. It is a small antimicrobial peptide released by neutrophils, macrophages or keratinocytes. Besides direct antimicrobial effects it is also involved in inflammatory response, immune regulation, angiogenesis, tissue repair or cancer regulation. Skin inflammatory diseases such atopic dermatitis or psoriasis have been respectively correlated to a lack of LL37 or LL37 overexpression. LL37 / hCAP18 is the single known human cathelicidin. It is a small antimicrobial peptide released by neutrophils, macrophages or keratinocytes. Besides direct antimicrobial effects it is also involved in inflammatory response, immune regulation, angiogenesis, tissue repair or cancer regulation. Skin inflammatory diseases such atopic dermatitis or psoriasis have been respectively correlated to a lack of LL37 or LL37 overexpression. LL37 / hCAP18 is the single known human cathelicidin. It is a small antimicrobial peptide released by neutrophils, macrophages or keratinocytes. Besides direct antimicrobial effects it is also involved in inflammatory response, immune regulation, angiogenesis, tissue repair or cancer regulation. Skin inflammatory diseases such atopic dermatitis or psoriasis have been respectively correlated to a lack of LL37 or LL37 overexpression. LL37 / hCAP18 is the single known human cathelicidin. It is a small antimicrobial peptide released by neutrophils, macrophages or keratinocytes. Besides direct antimicrobial effects it is also involved in inflammatory response, immune regulation, angiogenesis, tissue repair or cancer regulation. Skin inflammatory diseases such atopic dermatitis or psoriasis have been respectively correlated to a lack of LL37 or LL37 overexpression. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Elafin (SKALP) is mainly produced by epithelial cells and keratinocytes but almost undetectable in normal skin. Its level increases in psoriatic lesions and is enhanced by IL-1 and TNF-alpha (i.e. a pro-inflammatory microenvironment). It inhibits various proteases including elastase and thus protects tissues against the damage caused by pathological acute and chronic inflammation, limits immune response during chronic inflammation and exhibits antimicrobial effects.Elafin (SKALP) is mainly produced by epithelial cells and keratinocytes but almost undetectable in normal skin. Its level increases in psoriatic lesions and is enhanced by IL-1 and TNF-alpha (i.e. a pro-inflammatory microenvironment). It inhibits various proteases including elastase and thus protects tissues against the damage caused by pathological acute and chronic inflammation, limits immune response during chronic inflammation and exhibits antimicrobial effects.Elafin (SKALP) is mainly produced by epithelial cells and keratinocytes but almost undetectable in normal skin. Its level increases in psoriatic lesions and is enhanced by IL-1 and TNF-alpha (i.e. a pro-inflammatory microenvironment). It inhibits various proteases including elastase and thus protects tissues against the damage caused by pathological acute and chronic inflammation, limits immune response during chronic inflammation and exhibits antimicrobial effects.Elafin (SKALP) is mainly produced by epithelial cells and keratinocytes but almost undetectable in normal skin. Its level increases in psoriatic lesions and is enhanced by IL-1 and TNF-alpha (i.e. a pro-inflammatory microenvironment). It inhibits various proteases including elastase and thus protects tissues against the damage caused by pathological acute and chronic inflammation, limits immune response during chronic inflammation and exhibits antimicrobial effects. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Derived from the cleavage of profilaggrin, a molecule present in the keratohyaline granules of granular keratinocytes, filaggrin is a known marker of terminal differentiation of keratinocytes and a major constituent of stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin produces a mix of amino acids constituting NMF (Natural Moisturizing Factor) and is thus involved in skin hydration. Impairment of epidermal barrier function owing to filaggrin deficiency can promote inflammation and T cell infiltration and induce atopic dermatitis. Derived from the cleavage of profilaggrin, a molecule present in the keratohyaline granules of granular keratinocytes, filaggrin is a known marker of terminal differentiation of keratinocytes and a major constituent of stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin produces a mix of amino acids constituting NMF (Natural Moisturizing Factor) and is thus involved in skin hydration. Impairment of epidermal barrier function owing to filaggrin deficiency can promote inflammation and T cell infiltration and induce atopic dermatitis. Derived from the cleavage of profilaggrin, a molecule present in the keratohyaline granules of granular keratinocytes, filaggrin is a known marker of terminal differentiation of keratinocytes and a major constituent of stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin produces a mix of amino acids constituting NMF (Natural Moisturizing Factor) and is thus involved in skin hydration. Impairment of epidermal barrier function owing to filaggrin deficiency can promote inflammation and T cell infiltration and induce atopic dermatitis. Derived from the cleavage of profilaggrin, a molecule present in the keratohyaline granules of granular keratinocytes, filaggrin is a known marker of terminal differentiation of keratinocytes and a major constituent of stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin produces a mix of amino acids constituting NMF (Natural Moisturizing Factor) and is thus involved in skin hydration. Impairment of epidermal barrier function owing to filaggrin deficiency can promote inflammation and T cell infiltration and induce atopic dermatitis. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Mainly involved in skin hydration, lubrication of joints and space filling, Hyaluronic Acid (HA) also constitutes a framework through which cells migrate. Almost all cells can attach HA via membrane receptors (either CD44 or RHAMM), including inflammatory cells which may be activated to enhance immune response. Interestingly, HA of high molecular size (>1,000kDa) is antiangiogenic and immunosuppressive, whereas smaller polymers of HA which accumulates during inflammation are potent inducers of inflammation and angiogenesis. Mainly involved in skin hydration, lubrication of joints and space filling, Hyaluronic Acid (HA) also constitutes a framework through which cells migrate. Almost all cells can attach HA via membrane receptors (either CD44 or RHAMM), including inflammatory cells which may be activated to enhance immune response. Interestingly, HA of high molecular size (>1,000kDa) is antiangiogenic and immunosuppressive, whereas smaller polymers of HA which accumulates during inflammation are potent inducers of inflammation and angiogenesis. Mainly involved in skin hydration, lubrication of joints and space filling, Hyaluronic Acid (HA) also constitutes a framework through which cells migrate. Almost all cells can attach HA via membrane receptors (either CD44 or RHAMM), including inflammatory cells which may be activated to enhance immune response. Interestingly, HA of high molecular size (>1,000kDa) is antiangiogenic and immunosuppressive, whereas smaller polymers of HA which accumulates during inflammation are potent inducers of inflammation and angiogenesis. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Mainly involved in skin hydration, lubrication of joints and space filling, Hyaluronic Acid (HA) also constitutes a framework through which cells migrate. Almost all cells can attach HA via membrane receptors (either CD44 or RHAMM), including inflammatory cells which may be activated to enhance immune response. Interestingly, HA of high molecular size (>1,000kDa) is antiangiogenic and immunosuppressive, whereas smaller polymers of HA which accumulates during inflammation are potent inducers of inflammation and angiogenesis. To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Under the activation of Toll-like receptors (by pathogens), some specific peripheral precursors differentiate into CD209+ (DC-SIGN) cells which are part of the innate immune system and located in the dermis, especially in inflamed cutaneous area. Either presenting a macrophage-like or a dendritic cell-like phenotype, they are actually macrophages and use CD209 to facilitate uptake of bacteria and achieve phagocytosis. Under the activation of Toll-like receptors (by pathogens), some specific peripheral precursors differentiate into CD209+ (DC-SIGN) cells which are part of the innate immune system and located in the dermis, especially in inflamed cutaneous area. Either presenting a macrophage-like or a dendritic cell-like phenotype, they are actually macrophages and use CD209 to facilitate uptake of bacteria and achieve phagocytosis. Under the activation of Toll-like receptors (by pathogens), some specific peripheral precursors differentiate into CD209+ (DC-SIGN) cells which are part of the innate immune system and located in the dermis, especially in inflamed cutaneous area. Either presenting a macrophage-like or a dendritic cell-like phenotype, they are actually macrophages and use CD209 to facilitate uptake of bacteria and achieve phagocytosis. Human Beta defensin 2, 3 and 4 are antimicrobial peptides produced by keratinocytes when stimulated by a contact with microorganisms or some inflammatory cytokines such as IL-1a or TNFa. Their level increases on inflammatory sites whereas a lack of bêta defensins can induce skin diseases such as psoriasis or atopic dermatitis.Human Beta defensin 2, 3 and 4 are antimicrobial peptides produced by keratinocytes when stimulated by a contact with microorganisms or some inflammatory cytokines such as IL-1a or TNFa. Their level increases on inflammatory sites whereas a lack of bêta defensins can induce skin diseases such as psoriasis or atopic dermatitis.Human Beta defensin 2, 3 and 4 are antimicrobial peptides produced by keratinocytes when stimulated by a contact with microorganisms or some inflammatory cytokines such as IL-1a or TNFa. Their level increases on inflammatory sites whereas a lack of bêta defensins can induce skin diseases such as psoriasis or atopic dermatitis.Human Beta defensin 2, 3 and 4 are antimicrobial peptides produced by keratinocytes when stimulated by a contact with microorganisms or some inflammatory cytokines such as IL-1a or TNFa. Their level increases on inflammatory sites whereas a lack of bêta defensins can induce skin diseases such as psoriasis or atopic dermatitis. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.CD1a is a lipid-presenting molecule expressed on Langerhans cells. It amplifies inflammatory responses mediated by TH17 cells reacting to self lipid antigens. Targeting CD1 may therefore be a strategy to alleviate inflammation in some inflammatory skin diseases such as psoriasis for example. CD1a is a lipid-presenting molecule expressed on Langerhans cells. It amplifies inflammatory responses mediated by TH17 cells reacting to self lipid antigens. Targeting CD1 may therefore be a strategy to alleviate inflammation in some inflammatory skin diseases such as psoriasis for example. CD1a is a lipid-presenting molecule expressed on Langerhans cells. It amplifies inflammatory responses mediated by TH17 cells reacting to self lipid antigens. Targeting CD1 may therefore be a strategy to alleviate inflammation in some inflammatory skin diseases such as psoriasis for example. CD1a is a lipid-presenting molecule expressed on Langerhans cells. It amplifies inflammatory responses mediated by TH17 cells reacting to self lipid antigens. Targeting CD1 may therefore be a strategy to alleviate inflammation in some inflammatory skin diseases such as psoriasis for example. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Prostaglandin E-2 (PGE-2) is a lipid-derived signaling molecule found in mammalian skin, especially in fibroblasts. Levels of Prostaglandin E-2 (PGE-2) increase with chronological aging and following sun exposure, inducing an inflammatory state and therefore skin damages associated to ageing such as collagen decrease. to be completedDesmogleins 1 - 4 are calcium-binding transmembrane glycoprotein belonging to the cadherin superfamily. As components of desmosomes, they are involved in the cohesion between keratinocytes and corneocytes. Desmoglein 2 is more abundant in the basal layer whereas Desmoglein 1 level is higher in differentiated keratinocytes. But, even if the role of each desmoglein type vary, a defect in desmoglein expression may lead to an impaired skin barrier. to be completedTo be completedPerlecan is a heparan sulfate proteoglycan. Basal keratinocytes produce Perlecan which is accumulated at the dermal epidermal junction (DEJ) level while Perlecan coming from fibroblasts is accumulated in the dermal extracellular matrix. At the DEJ level, Perlecan allows to maintain the self-renewal capacities of keratinocytes and is involved in their survival and differentiation.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Corneocytes, the final stage of keratinocyte differentiation, are linked together by protein complexes called corneodesmosomes composed of proteins such as corneodesmosin (CDSN), desmoglein 1 (DSG1) and desmocollin 1 (DSC1). Kallikrein 7, capable of cleaving CDSN and DSC1, and kallikrein 5, capable of cleaving CDSN, DSC1 and DSG1, are two proteolytic enzymes involved in the loss of cohesion of corneocytes associated with desquamation. The synthesis and activity of these 2 enzymes must therefore be correctly regulated to ensure desquamation and therefore epidermal renewal at an appropriate level.Corneocytes, the final stage of keratinocyte differentiation, are linked together by protein complexes called corneodesmosomes composed of proteins such as corneodesmosin (CDSN), desmoglein 1 (DSG1) and desmocollin 1 (DSC1). Kallikrein 7, capable of cleaving CDSN and DSC1, and kallikrein 5, capable of cleaving CDSN, DSC1 and DSG1, are two proteolytic enzymes involved in the loss of cohesion of corneocytes associated with desquamation. The synthesis and activity of these 2 enzymes must therefore be correctly regulated to ensure desquamation and therefore epidermal renewal at an appropriate level. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Corneocytes, the final stage of keratinocyte differentiation, are linked together by protein complexes called corneodesmosomes composed of proteins such as corneodesmosin (CDSN), desmoglein 1 (DSG1) and desmocollin 1 (DSC1). Kallikrein 7, capable of cleaving CDSN and DSC1, and kallikrein 5, capable of cleaving CDSN, DSC1 and DSG1, are two proteolytic enzymes involved in the loss of cohesion of corneocytes associated with desquamation. The synthesis and activity of these 2 enzymes must therefore be correctly regulated to ensure desquamation and therefore epidermal renewal at an appropriate level.To be completedTo be completedCorneodesmosin is a protein secreted by granular keratinocytes via the lamellar bodies and incorporated into desmosomes shortly before their transformation into corneodesmosomes. Corneodesmosin displays adhesive properties by acting like a Velcro and is therefore involved in skin barrier function. Moreover, corneodesmosin is then sequentially proteolyzed as corneocytes migrate towards the skin surface, thus allowing appropriate desquamation and skin barrier renewal. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Please contact directly the testing laboratory to define the details of this assay.To be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.The α2β1 integrin is an heterodimeric transmembrane protein able to interact with collagen I and III. Abundantly and constitutively expressed by basal keratinocytes in intact skin, the α2β1 integrin is also upregulated in wounds. This integrin is also expressed by endothelial cells and able to interact with VEGF. The α2β1 integrin seems to regulate angiogenesis and inflammatory response, but also matrix remodeling during wound healing. The α2β1 integrin is an heterodimeric transmembrane protein able to interact with collagen I and III. Abundantly and constitutively expressed by basal keratinocytes in intact skin, the α2β1 integrin is also upregulated in wounds. This integrin is also expressed by endothelial cells and able to interact with VEGF. The α2β1 integrin seems to regulate angiogenesis and inflammatory response, but also matrix remodeling during wound healing. The α2β1 integrin is an heterodimeric transmembrane protein able to interact with collagen I and III. Abundantly and constitutively expressed by basal keratinocytes in intact skin, the α2β1 integrin is also upregulated in wounds. This integrin is also expressed by endothelial cells and able to interact with VEGF. The α2β1 integrin seems to regulate angiogenesis and inflammatory response, but also matrix remodeling during wound healing. Ki67 is a nuclear protein related to cell cycle and synthesized by all proliferating cells while deficient in resting cells. Proliferating cell nuclear antigen (PCNA) is another well-known nuclear protein which participates in cell proliferation by mediating DNA polymerase. Those two proteins are therefore two well-established proliferation-associated proteins used to probe cell proliferation during wound repair.Ki67 is a nuclear protein related to cell cycle and synthesized by all proliferating cells while deficient in resting cells. Proliferating cell nuclear antigen (PCNA) is another well-known nuclear protein which participates in cell proliferation by mediating DNA polymerase. Those two proteins are therefore two well-established proliferation-associated proteins used to probe cell proliferation during wound repair. Lumican, a small leucine-rich proteoglycan, is expressed in the extracellular matrix of several tissues including skin. Lumican regulates collagen fibrillogenesis, fibroblast contractility and keratinocyte phenotype, migration and proliferation. It is also involved in inflammatory cell recruitment and stimulation, in angiogenesis, and is the only member of the small leucine-rich proteoglycan famility expressed by the epithelia during wound healing. Overall, it promotes normal wound healing.To be completedTo be completedPerlecan is a heparan sulfate proteoglycan. Basal keratinocytes produce Perlecan which is accumulated at the dermal epidermal junction (DEJ) level while Perlecan coming from fibroblasts is accumulated in the dermal extracellular matrix. At the DEJ level, Perlecan allows to maintain the self-renewal capacities of keratinocytes and is involved in their survival and differentiation. During wound healing, Perlecan promotes cellular proliferation, differentiation, extracellular matrix synthesis and therefore tissue repair and angiogenesis.To be completedTo be completedPsoriasin (S100A7) is a calcium responsive signalling protein produced by keratinocytes. Besides its role as an antimicrobial peptide, it is also involved in various processes including skin inflammation and keratinocyte differentiation. Psoriasin expression is upregulated in wounds, particularly at the wound edges where it acts as a fundamental regulator of keratinocyte migration. Psoriasin is therefore essential in wound healing and has been suggested as a potential wound healing biomarker. Psoriasin (S100A7) is a calcium responsive signalling protein produced by keratinocytes. Besides its role as an antimicrobial peptide, it is also involved in various processes including skin inflammation and keratinocyte differentiation. Psoriasin expression is upregulated in wounds, particularly at the wound edges where it acts as a fundamental regulator of keratinocyte migration. Psoriasin is therefore essential in wound healing and has been suggested as a potential wound healing biomarker. Psoriasin (S100A7) is a calcium responsive signalling protein produced by keratinocytes. Besides its role as an antimicrobial peptide, it is also involved in various processes including skin inflammation and keratinocyte differentiation. Psoriasin expression is upregulated in wounds, particularly at the wound edges where it acts as a fundamental regulator of keratinocyte migration. Psoriasin is therefore essential in wound healing and has been suggested as a potential wound healing biomarker. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. It also regulates cell migration, redox response, inflammation, epidermis re-epithelialization, granulation formation and therefore proper wound healing.Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. It also regulates cell migration, redox response, inflammation, epidermis re-epithelialization, granulation formation and therefore proper wound healing.Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. It also regulates cell migration, redox response, inflammation, epidermis re-epithelialization, granulation formation and therefore proper wound healing.The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Claudin 1 (CLDN-1) and 4 (CLDN-4) are transmembrane proteins constituting the tight junctions which maintain the keratinocytes closely associated in the epidermis. A decrease of Claudin level beyond a threshold may alter skin barrier function and induce skin inflammation. This has been observed in some atopic dermatitis cases. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Caspase-14 is a protease initially expressed in the suprabasal layers of the epidermis in an inactive form and then converted into an active form essentially present in the stratum corneum. It is involved in the terminal differentiation of keratinocytes and thus the establishment of the skin barrier, but also in the filaggrin proteolysis and the formation of NMF (Natural Moisturizing Factor) allowing the hydration and thus the functionality of the skin barrier as well as in the protection of the skin against UVB. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.The α2β1 integrin is an heterodimeric transmembrane protein able to interact with collagen I and III. Abundantly and constitutively expressed by basal keratinocytes in intact skin, the α2β1 integrin is also upregulated in wounds. This integrin is also expressed by endothelial cells and able to interact with VEGF. The α2β1 integrin seems to regulate angiogenesis and inflammatory response, but also matrix remodeling during wound healing. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Ki67 is a nuclear protein related to cell cycle and synthesized by all proliferating cells while deficient in resting cells. Proliferating cell nuclear antigen (PCNA) is another well-known nuclear protein which participates in cell proliferation by mediating DNA polymerase. Those two proteins are therefore two well-established proliferation-associated proteins used to probe cell proliferation during wound repair. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Psoriasin (S100A7) is a calcium responsive signalling protein produced by keratinocytes. Besides its role as an antimicrobial peptide, it is also involved in various processes including skin inflammation and keratinocyte differentiation. Psoriasin expression is upregulated in wounds, particularly at the wound edges where it acts as a fundamental regulator of keratinocyte migration. Psoriasin is therefore essential in wound healing and has been suggested as a potential wound healing biomarker. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. It also regulates cell migration, redox response, inflammation, epidermis re-epithelialization, granulation formation and therefore proper wound healing. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Mainly expressed in suprabasal layers and activated during keratinocyte cornification, Caspase 14 is a protease inducing filaggrin proteolysis. This allows the accumulation of free amino-acids such as urocanic acid and pyrrolidone carboxylic acid which constitute the NMF involved in skin hydration. Mainly expressed in suprabasal layers and activated during keratinocyte cornification, Caspase 14 is a protease inducing filaggrin proteolysis. This allows the accumulation of free amino-acids such as urocanic acid and pyrrolidone carboxylic acid which constitute the NMF involved in skin hydration. Mainly expressed in suprabasal layers and activated during keratinocyte cornification, Caspase 14 is a protease inducing filaggrin proteolysis. This allows the accumulation of free amino-acids such as urocanic acid and pyrrolidone carboxylic acid which constitute the NMF involved in skin hydration. Matrix metallopeptidases (MMP) are various proteases located in dermal extracellular matrix and involved in extracellular matrix remodelling and therefore biological mechanisms such as wound healing or skin hydration. Matrix metallopeptidases (MMP) are various proteases located in dermal extracellular matrix and involved in extracellular matrix remodelling and therefore biological mechanisms such as wound healing or skin hydration. Matrix metallopeptidases (MMP) are various proteases located in dermal extracellular matrix and involved in extracellular matrix remodelling and therefore biological mechanisms such as wound healing or skin hydration. Derived from the cleavage of profilaggrin, a molecule present in the keratohyaline granules of granular keratinocytes, filaggrin is a known marker of terminal differentiation of keratinocytes and a major constituent of stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin produces a mix of amino acids constituting NMF (Natural Moisturizing Factor) and is thus involved in skin hydration. Derived from the cleavage of profilaggrin, a molecule present in the keratohyaline granules of granular keratinocytes, filaggrin is a known marker of terminal differentiation of keratinocytes and a major constituent of stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin produces a mix of amino acids constituting NMF (Natural Moisturizing Factor) and is thus involved in skin hydration. Derived from the cleavage of profilaggrin, a molecule present in the keratohyaline granules of granular keratinocytes, filaggrin is a known marker of terminal differentiation of keratinocytes and a major constituent of stratum corneum. It thus participates in the skin's barrier function. Under the action of proteases including caspase 14, filaggrin produces a mix of amino acids constituting NMF (Natural Moisturizing Factor) and is thus involved in skin hydration. The key molecule involved in skin moisture is hyaluronic acid (HA). It corresponds to the main skin extracellular matrix glycosaminoglycan and has unique capacity in retaining water, thus allowing for proper skin suppleness and stiffness. The key molecule involved in skin moisture is hyaluronic acid (HA). It corresponds to the main skin extracellular matrix glycosaminoglycan and has unique capacity in retaining water, thus allowing for proper skin suppleness and stiffness. Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of these specific studies.Skin ageing is associated with an increase in senescent cell percentage. As β-galactosidase activity increases significantly in senescent cells, this marker is commonly used to assess the extent of skin ageing. An anti-ageing product can therefore decrease this activity.Skin ageing is associated with an increase in senescent cell percentage. As β-galactosidase activity increases significantly in senescent cells, this marker is commonly used to assess the extent of skin ageing. An anti-ageing product can therefore decrease this activity.Skin ageing is associated with an increase in senescent cell percentage. As β-galactosidase activity increases significantly in senescent cells, this marker is commonly used to assess the extent of skin ageing. An anti-ageing product can therefore decrease this activity. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Synthesised by the keratinocytes of the spinous layer and then secreted via the lamellar bodies, corneodesmosin is then incorporated into the corneodesmosomes which ensure cohesion between the corneocytes of the stratum corneum. During skin ageing, a degradation of this protein, notably linked to an increase in skin pH which activates certain proteases, leads to a weakening of the skin barrier. An anti-ageing agent can slow down the degradation of corneodesmosin and thus help maintain the skin barrier. To be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Sirtuin 1 is an enzyme with many functions. It limits oxidative stress, DNA damage, apoptosis, participates in inflammation, promotes barrier function, wound healing and endothelial function. By targeting this enzyme, anti-ageing products can promote its action and thus limit skin ageing. Sirtuin 1 is an enzyme with many functions. It limits oxidative stress, DNA damage, apoptosis, participates in inflammation, promotes barrier function, wound healing and endothelial function. By targeting this enzyme, anti-ageing products can promote its action and thus limit skin ageing. Sirtuin 1 is an enzyme with many functions. It limits oxidative stress, DNA damage, apoptosis, participates in inflammation, promotes barrier function, wound healing and endothelial function. By targeting this enzyme, anti-ageing products can promote its action and thus limit skin ageing. Sirtuin 1 is an enzyme with many functions. It limits oxidative stress, DNA damage, apoptosis, participates in inflammation, promotes barrier function, wound healing and endothelial function. By targeting this enzyme, anti-ageing products can promote its action and thus limit skin ageing. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of these specific studies.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Caspase 9 is a protease initiating the activation cascade which leads to apoptosis. It can therefore be used as a marker for apoptotic cells. An anti-ageing product can aim to regulate apoptosis which is naturally altered during skin ageing.Caspase 9 is a protease initiating the activation cascade which leads to apoptosis. It can therefore be used as a marker for apoptotic cells. An anti-ageing product can aim to regulate apoptosis which is naturally altered during skin ageing.Caspase 9 is a protease initiating the activation cascade which leads to apoptosis. It can therefore be used as a marker for apoptotic cells. An anti-ageing product can aim to regulate apoptosis which is naturally altered during skin ageing.Caspase 9 is a protease initiating the activation cascade which leads to apoptosis. It can therefore be used as a marker for apoptotic cells. An anti-ageing product can aim to regulate apoptosis which is naturally altered during skin ageing. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Fibronectin is an extracellular matrix (ECM) protein that dictates cell adhesion, spreading, migration, proliferation and apoptosis. It is active through all stages of wound healing. Plasma fibronectin primarily helps to form the clot and assemble a cell-ECM matrix in the initial phase of wound healing. Cellular derived fibronectin regulates the later stages of tissue remodeling via locally expressed fibronectine assembly which regulates cell behaviour and granulation tissue formation. Fibronectin is also involved in the control of debris phagocytosis and the inflammation process preparing the site before cell recruitment and proliferation.To be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.The cluster of differentiation 44 (CD44) is on all skin cells. This membrane receptor is involved in cell adhesion and migration, skin inflammation or metastasis, and skin hydration as a key cell receptor for hyaluronic acid.The cluster of differentiation 44 (CD44) is on all skin cells. This membrane receptor is involved in cell adhesion and migration, skin inflammation or metastasis, and skin hydration as a key cell receptor for hyaluronic acid. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.The extracellular matrix synthesised by fibroblasts contains carbohydrate macromolecules called glycosaminoglycans (GAGs) which are generally covalently linked to a protein to form proteoglycans. These molecules (especially hyaluronic acid) contribute to the suppleness and firmness of the skin by promoting its hydration. The extracellular matrix synthesised by fibroblasts contains carbohydrate macromolecules called glycosaminoglycans (GAGs) which are generally covalently linked to a protein to form proteoglycans. These molecules (especially hyaluronic acid) contribute to the suppleness and firmness of the skin by promoting its hydration.Synthesised in the keratinocyte cytoplasm of stratum granulosum, involucrin is a major constituent of the cornified enveloppe, leads to the death of the keratinocytes and serves as a primer for the binding of other proteins such as loricrin. Known as differentiation marker of keratinocytes, it plays an active role in the skin's barrier function, limiting water loss and thus favouring appropriate skin hydration. Synthesised in the keratinocyte cytoplasm of stratum granulosum, involucrin is a major constituent of the cornified enveloppe, leads to the death of the keratinocytes and serves as a primer for the binding of other proteins such as loricrin. Known as differentiation marker of keratinocytes, it plays an active role in the skin's barrier function, limiting water loss and thus favouring appropriate skin hydration. Synthesised in the keratinocyte cytoplasm of stratum granulosum, involucrin is a major constituent of the cornified enveloppe, leads to the death of the keratinocytes and serves as a primer for the binding of other proteins such as loricrin. Known as differentiation marker of keratinocytes, it plays an active role in the skin's barrier function, limiting water loss and thus favouring appropriate skin hydration.The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedThe analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of these specific studies.Beta defensin 2 is an antimicrobial peptide with pro-inflammatory and chemotactic properties presenting greater amounts in the epidermis of acne-prone skin. An anti-acne product should decrease this amount. Beta defensin 2 is an antimicrobial peptide with pro-inflammatory and chemotactic properties presenting greater amounts in the epidermis of acne-prone skin. An anti-acne product should decrease this amount. Beta defensin 2 is an antimicrobial peptide with pro-inflammatory and chemotactic properties presenting greater amounts in the epidermis of acne-prone skin. An anti-acne product should decrease this amount. Beta defensin 2 is an antimicrobial peptide with pro-inflammatory and chemotactic properties presenting greater amounts in the epidermis of acne-prone skin. An anti-acne product should decrease this amount. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.In acne-prone skin, MMP1 and MMP3 are overexpressed, inducing remodelling of the extracellular matrix in the dermis. Anti-acne products can decrease the expression level of these enzymes.In acne-prone skin, MMP1 and MMP3 are overexpressed, inducing remodelling of the extracellular matrix in the dermis. Anti-acne products can decrease the expression level of these enzymes. In acne-prone skin, MMP1 and MMP3 are overexpressed, inducing remodelling of the extracellular matrix in the dermis. Anti-acne products can decrease the expression level of these enzymes.The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Squalene overproduction and oxydation are observed in acne-prone skin. An anti-acne product decreases both the amount of squalene produced and the ratio of peroxidised squalene to squalene.Acne is an inflammatory disease, characterised by higher levels of inflammatory cytokines such as interleukin 8. An anti-acne product should reduce this level. Acne is an inflammatory disease, characterised by higher levels of inflammatory cytokines such as interleukin 8. An anti-acne product should reduce this level. Acne is an inflammatory disease, characterised by higher levels of inflammatory cytokines such as interleukin 8. An anti-acne product should reduce this level. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Acne is an inflammatory disease, characterised by higher levels of inflammatory cytokines such as interleukin 8. An anti-acne product should reduce this level. In acne-prone skin, the IA strain of P. acnes is more abundant and stimulates the production of IGF-1 by keratinocytes. An anti-acne product can reduce this production, which is correlated with keratinocyte proliferation and differentiation.In acne-prone skin, the IA strain of P. acnes is more abundant and stimulates the production of IGF-1 by keratinocytes. An anti-acne product can reduce this production, which is correlated with keratinocyte proliferation and differentiation.In acne-prone skin, the IA strain of P. acnes is more abundant and stimulates the production of IGF-1 by keratinocytes. An anti-acne product can reduce this production, which is correlated with keratinocyte proliferation and differentiation. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.In acne-prone skin, the IA strain of the P. acnes bacterium is more present and stimulates the production of involucrin by the keratinocytes. An anti-acne product can reduce this production, which is correlated with the differentiation of keratinocytes.In acne-prone skin, the IA strain of the P. acnes bacterium is more present and stimulates the production of involucrin by the keratinocytes. An anti-acne product can reduce this production, which is correlated with the differentiation of keratinocytes.In acne-prone skin, the IA strain of the P. acnes bacterium is more present and stimulates the production of involucrin by the keratinocytes. An anti-acne product can reduce this production, which is correlated with the differentiation of keratinocytes.KGF is a growth factor stimulating sebocyte and keratinocyte proliferation and differentiation. In acne-prone skin, overproliferation of keratinocytes and overproduction of sebum related to the proliferation and differentiation of sebocytes are observed. KGF is a growth factor stimulating sebocyte and keratinocyte proliferation and differentiation. In acne-prone skin, overproliferation of keratinocytes and overproduction of sebum related to the proliferation and differentiation of sebocytes are observed. KGF is a growth factor stimulating sebocyte and keratinocyte proliferation and differentiation. In acne-prone skin, overproliferation of keratinocytes and overproduction of sebum related to the proliferation and differentiation of sebocytes are observed. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.C. acnes is the dominant resident bacterial species in the sebaceous follicles. It includes various subtypes. The proportion of phylotype IA1, which virulence and inflammatory potential is higher than other phylotypes, is usually more abundant in acne-prone skin. An anti-acneic product acts by decreasing phylotype IA1 proportion.C. acnes is the dominant resident bacterial species in the sebaceous follicles. It includes various subtypes. The proportion of phylotype IA1, which virulence and inflammatory potential is higher than other phylotypes, is usually more abundant in acne-prone skin. An anti-acneic product acts by decreasing phylotype IA1 proportion.C. acnes is the dominant resident bacterial species in the sebaceous follicles. It includes various subtypes. The proportion of phylotype IA1, which virulence and inflammatory potential is higher than other phylotypes, is usually more abundant in acne-prone skin. An anti-acneic product acts by decreasing phylotype IA1 proportion. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Please contact directly the testing laboratory to define the details of this assayPlease contact directly the testing laboratory to define the details of these specific studies.In acne-prone skin, high levels of testosterone, which is then converted to dihydrotestosterone (DHT) by 5-alpha reductase, leads to an overproduction of sebum. An acne product can restore normal sebum production by specifically targeting 5-alpha reductase. In acne-prone skin, high levels of testosterone, which is then converted to dihydrotestosterone (DHT) by 5-alpha reductase, leads to an overproduction of sebum. An acne product can restore normal sebum production by specifically targeting 5-alpha reductase. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Please contact directly the testing laboratory to define the details of this assay.Please contact directly the testing laboratory to define the details of this assay.Collagen IV is a major component of the dermal-epidermal junction and the basement membrane on which endothelial cells are attached. It is therefore essential for anchoring the epidermis and maintaining the integrity of the skin barrier. It is also involved in the skin barrier restoration during wound healing and it modulates keratinocyte proliferation and differentiationas well as endothelial cells.Collagen IV is a major component of the dermal-epidermal junction and the basement membrane on which endothelial cells are attached. It is therefore essential for anchoring the epidermis and maintaining the integrity of the skin barrier. It is also involved in the skin barrier restoration during wound healing and it modulates keratinocyte proliferation and differentiationas well as endothelial cells.Collagen IV is a major component of the dermal-epidermal junction and the basement membrane on which endothelial cells are attached. It is therefore essential for anchoring the epidermis and maintaining the integrity of the skin barrier. It is also involved in the skin barrier restoration during wound healing and it modulates keratinocyte proliferation and differentiationas well as endothelial cells.Collagen IV is a major component of the dermal-epidermal junction and the basement membrane on which endothelial cells are attached. It is therefore essential for anchoring the epidermis and maintaining the integrity of the skin barrier. It is also involved in the skin barrier restoration during wound healing and it modulates keratinocyte proliferation and differentiationas well as endothelial cells.Squalene overproduction and oxydation are observed in acne-prone skin. An anti-acne product decreases both the amount of squalene produced and the ratio of peroxidised squalene to squalene. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Biodegradability is used to assess the environmental characteristics of decomposition and mineralization by microorganisms of organic substances. The OECD distinguishes between “easy” biodegradability and “intrinsic” biodegradability. OECD testing methods are chosen based on the properties of each substance.Biodegradability is used to assess the environmental characteristics of decomposition and mineralization by microorganisms of organic substances. The OECD distinguishes between “easy” biodegradability and “intrinsic” biodegradability. OECD testing methods are chosen based on the properties of each substance.Biodegradability is used to assess the environmental characteristics of decomposition and mineralization by microorganisms of organic substances. The OECD distinguishes between “easy” biodegradability and “intrinsic” biodegradability. OECD testing methods are chosen based on the properties of each substance.Biodegradability is used to assess the environmental characteristics of decomposition and mineralization by microorganisms of organic substances. The OECD distinguishes between “easy” biodegradability and “intrinsic” biodegradability. OECD testing methods are chosen based on the properties of each substance.Biodegradability is used to assess the environmental characteristics of decomposition and mineralization by microorganisms of organic substances. The OECD distinguishes between “easy” biodegradability and “intrinsic” biodegradability. OECD testing methods are chosen based on the properties of each substance.Laminin 332 (previously called Laminin V) is an essential component of the dermal-epidermal junction. It allows epidermal attachment and modulates the differentiation of epidermal stem cells. Thus, Laminin 332 synthesis may modulate the skin barrier integrity and its function. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedPlease contact directly the testing laboratory to define the details of these specific studies.To be completedPlease contact directly the testing laboratory to define the details of this assay. To be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedPlease contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of this assay. To be completedTo be completedCountingCountingCountingCountingCountingCountingCountingCountingCountingCountingCountingCountingCountingCountingCountingTheoretical analysis: hypothesis that the entire container is solubilised in the contents. It defines critical substances when there is accurate data on material composition. The different materials of the packaging are separated and subjected each to specific incubation conditions (3 hours to 100°C for example). 4 solvents of different polarity are used to isolate extractables and potentially critical migrants. Visual and olfactory assessment of packaging and product variations after specific temperature and duration incubationExposure of packaging materials to physically-chemically defined excipients as close to the container years from normal operating conditions (duration, humidity, temperature) Analysis of interactions with the complete product after specific incubation (temperature, humidity, duration) In acne-prone skin, high levels of testosterone, which is then converted to dihydrotestosterone (DHT) by 5-alpha reductase, leads to an overproduction of sebum. An acne product can restore normal sebum production by specifically targeting 5-alpha reductase. In acne-prone skin, high levels of testosterone, which is then converted to dihydrotestosterone (DHT) by 5-alpha reductase, leads to an overproduction of sebum. An acne product can restore normal sebum production by specifically targeting 5-alpha reductase. To be completedTo be completedTo be completedTo be completedTo be completedEvaluation of the decrease in contamination to levels ensuring the microbial limits established for Categories 1 and 2, after an artificial contamination of the product by Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus brasiliensisMeasurement of water activity in oil, powders and other low water content productsDetection on a non-selective agar of viable microorganisms and the microbial growth inhibitionDetection on a non-selective agar of viable microorganisms and the microbial growth inhibitionEvaluation of the contamination level of the yeast and moulds except pathogens Determination of the DLU (date of minimum durability). Evaluation of the microbiological, chemical, physical stability of the product under specific storage conditions of temperature, humidity and light : laboratory conditions, accelerated conditions or real time conditions of use, specific for each product.Theoritical definition for products durability under 30 months. Evaluation of the microbiological, chemical, physical stability of the product under specific storage conditions of temperature, humidity and light : laboratory conditions, accelerated conditions or real time conditions of use, specific for each product. Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.The HPRT system detects base pair mutations, frameshift mutations, small deletions and insertions.It is a genomic test measuring changes in gene expression of 200 genes relevant to the skin sensitization adverse outcome pathways (AOP).To assess distinction between sensitizing skin products and non- sensitizing skin products to classify and label the dangers of the product in an IATA (Integrated Approaches to Testing and Assessment). cf.OECD TGP 4.106MTT (3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide; thiazolyl blue) is a water soluble tetrazolium salt yielding a yellowish solution when prepared in media or salt solutions lacking phenol red. Dissolved MTT is converted to an insoluble purple formazan by cleavage of the tetrazolium ring by dehydrogenase enzymes. This water-insoluble formazan can be solubilized using isopropanol or other solvents, and the dissolved material is measured spectrophotometrically using absorbance as a function of concentration of converted dye.Measure of the cellular viability on oral epithelium. Other endpoints other than MTT/Histology are considered: e.g. TEER, LDH release, IL-1a release, ultrastructural analysis by SEM (partnered),…Assessment of the ability of a test chemical to induce cytotoxicity in a RhCE tissue. Tissue viability is measured by enzymatic conversion of the vital dye MTT by the viable cells of the tissue into a blue MTT formazan salt. Genomic Allergen Rapid Detection. Measurement of levels of gene transcripts in human myeloid origin cells. GARDpotency is an add-on to GARDskin, able to cf. OECD TGP 4.106.The goal of the study is to evaluate the potential toxicity of reference compounds on daily exposure. The viability, cytotoxicity and inflammation to small and large airways can be also evaluated.Identification of skin sensitisers and to rank sensitisers according to their potency. It combines viability measurement (MTT-Assay) with the detection of Interleukin-18 secretion from epiCS.This Skin Sensitisation and Potency. It is easy to perform and results strongly correlate with LLNA and human DSA data..Skin ageing is associated with an increase in senescent cell percentage. As β-galactosidase activity increases significantly in senescent cells, this marker is commonly used to assess the extent of skin ageing. An anti-ageing product can therefore decrease this activity.Method for identifying water soluble ocular corrosives and severe irritants as defined by the UN Globally Harmonized System of Classification and Labelling, Category 1. The assay is performed in a well where a confluent monolayer of Madin-Darby Canine Kidney (MDCK) is used as a separation between two chambers. It uses a fluorescein dye as marqueur. The test substance has the potential to impair the junctions of the MDCK cells and thus to increase the monolayer¡¯s permeability. Consequently the fluorescein passes through the monolayer and the fluorescein leakage (FL) increases. This Test method has been designed to provide information on a test substance absorption after its application to the surface of a skin sample separating the two chambers (a donor chamber and a receptor chamber) of a diffusion cell (Franz cell). The substance application should mimic human exposure, normally 1-5 mg/cm2 of skin for a solid and up to 10 µl/cm2 for liquids. Passage kinetics are determined by dosing the active substance at regular intervals in the fluid of the receiving compartment. As the skin is able to metabolize certain substances during percutaneous absorption, the metabolites of the test substance can also be analyzed. The cleavage product of XTT is soluble in water; a solubilization step is therefore not required. The tetrazolium salt XTT is cleaved to formazan by a complex cellular mechanism. This bioreduction occurs in viable cells only, and is related to NAD(P)H production through glycolysis. The test material (150 µL for liquids or solid with 150 µL of deionised water added on the top) is applied for up to 24 hours to the epidermal surfaces of skin discs (three skin discs are used for each test and control substance) in a two-compartment test system in which the skin discs function as the separation between the compartments. A dye-binding step incorporated into the test procedure permits to determine if the increase in ionic permeability is due to physical destruction of the stratum corneumThe time (in minutes) elapsed between application of the test substance to the membrane barrier and barrier penetration is used to predict the corrosivity of the test substance.The test method utilizes an artificial membrane designed to respond to corrosive substances in a manner similar to animal skin in situ. The test system is composed of two components, a synthetic macromolecular bio-barrier and a Chemical Detection System (which one detect the test substance). This test provides information on the availability by measuring the absorption of a test substance, applied to the surface of a skin sample separating two chambers (a donor chamber and a receptor chamber) of a diffusion cell. Static and flow-through diffusion cells are both acceptable. The NRU assays test eight concentrations of the test substance or the positive control (PC) by diluting the stock test substance solution in log dilutions to cover a large concentration range. This method evaluate cytotoxicity by the relative reduction in viability of cells exposed to the chemical in the presence versus absence of light. Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Please contact directly the testing laboratory to define the details of these specific studies.Interleukin 1 alpha (IL-1α) is a key pro-inflammatory cytokine of the innate immune response. It is released by immune cells such as monocytes and macrophages but also by keratinocytes after their activation or alteration. It is involved in various inflammatory skin diseases and is overexpressed in atopic dermatitis.Interleukin 1 alpha (IL-1α) is a key pro-inflammatory cytokine of the innate immune response. It is released by immune cells such as monocytes and macrophages but also by keratinocytes after their activation or alteration. It is involved in various inflammatory skin diseases and is overexpressed in atopic dermatitis.Interleukin 1 alpha (IL-1α) is a key pro-inflammatory cytokine of the innate immune response. It is released by immune cells such as monocytes and macrophages but also by keratinocytes after their activation or alteration. It is involved in various inflammatory skin diseases and is overexpressed in atopic dermatitis.CD1a is abundantly expressed on epidermal Langerhans cells and dermal dendritic cells which are implicated in contact dermatitis. After binding to allergens, CD1a is involved in T cell activation and therefore inflammatory response. It has been shown that a higher expression of CD1a augments intradermal T cell responses to some allergens. Moreover, a higher density of CD1a-positive Langerhans cells has been found in atopic dermatitis skin patients compared to healthy skin, with differences in the location and appearances of the cells. Spontaneous mutations or various factors such as UV radiation can cause cellular DNA damages. Some enzymes normally repair DNA. However, more and more alterations tend to accumulate during skin aging increasing the risk of cancer development. More or less innovative techniques can be used to assess the efficiency and relevance of DNA repair systems in cell cultures or biopsies. Spontaneous mutations or various factors such as UV radiation can cause cellular DNA damages. Some enzymes normally repair DNA. However, more and more alterations tend to accumulate during skin aging increasing the risk of cancer development. More or less innovative techniques can be used to assess the efficiency and relevance of DNA repair systems in cell cultures or biopsies. Spontaneous mutations or various factors such as UV radiation can cause cellular DNA damages. Some enzymes normally repair DNA. However, more and more alterations tend to accumulate during skin aging increasing the risk of cancer development. More or less innovative techniques can be used to assess the efficiency and relevance of DNA repair systems in cell cultures or biopsies. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.To be completedTo be completedTo be completedTo be completedThe key molecule involved in skin moisture is hyaluronic acid (HA). It corresponds to the main skin extracellular matrix glycosaminoglycan and has unique capacity in retaining water, thus allowing for proper skin suppleness and stiffness. Mainly involved in skin hydration, lubrication of joints and space filling, Hyaluronic Acid (HA) also constitutes a framework through which cells migrate. Almost all cells can attach HA via membrane receptors (either CD44 or RHAMM), including inflammatory cells which may be activated to enhance immune response. Interestingly, HA of high molecular size (>1,000kDa) is antiangiogenic and immunosuppressive, whereas smaller polymers of HA which accumulates during inflammation are potent inducers of inflammation and angiogenesis. Enzymes are used to cleave RNA into a small single-stranded fragment of 21 to 24 long nucleotides. Thus matured, microRNAs can regulate gene expression, by pairing with messenger RNAs carrying a homologous sequence. These are then degraded, or their translation is inhibited. Enzymes are used to cleave RNA into a small single-stranded fragment of 21 to 24 long nucleotides. Thus matured, microRNAs can regulate gene expression, by pairing with messenger RNAs carrying a homologous sequence. These are then degraded, or their translation is inhibited. Enzymes are used to cleave RNA into a small single-stranded fragment of 21 to 24 long nucleotides. Thus matured, microRNAs can regulate gene expression, by pairing with messenger RNAs carrying a homologous sequence. These are then degraded, or their translation is inhibited. Measure of the O2 consumption and the mitochondry activity. Measure of the O2 consumption and the mitochondry activity. Measure of the O2 consumption and the mitochondry activity. Mitochondria is the place of breathing and cellular energy production with the conversion of glucose to ATP. This process also involves O2 consumption and the production of reactive oxygen species (ROS) which level increases with ageing. ROS modulate epidermal differentiation but also collagen biosynthesis and degradation. They play therefore a role in skin regeneration and healing. An active ingredient may thus target mitochondria activity to improve skin regeneration either by boosting ATP production or by scavenging the excess amounts of free radicals. Mitochondria is the place of breathing and cellular energy production with the conversion of glucose to ATP. This process also involves O2 consumption and the production of reactive oxygen species (ROS) which level increases with ageing. ROS modulate epidermal differentiation but also collagen biosynthesis and degradation. They play therefore a role in skin regeneration and healing. An active ingredient may thus target mitochondria activity to improve skin regeneration either by boosting ATP production or by scavenging the excess amounts of free radicals. Mitochondria is the place of breathing and cellular energy production with the conversion of glucose to ATP. This process also involves O2 consumption and the production of reactive oxygen species (ROS) which level increases with ageing. ROS modulate epidermal differentiation but also collagen biosynthesis and degradation. They play therefore a role in skin regeneration and healing. An active ingredient may thus target mitochondria activity to improve skin regeneration either by boosting ATP production or by scavenging the excess amounts of free radicals. Mitochondria is the place of breathing and cellular energy production with the conversion of glucose to ATP. This process also involves O2 consumption and the production of reactive oxygen species (ROS) which level increases with ageing. ROS modulate epidermal differentiation but also collagen biosynthesis and degradation. They play therefore a role in skin regeneration and healing. An active ingredient may thus target mitochondria activity to improve skin regeneration either by boosting ATP production or by scavenging the excess amounts of free radicals. Mitochondria is the place of breathing and cellular energy with the conversion of glucose to ATP. This process includes several stages of metabolic reactions, including the "Krebs cycle." Mitochondria is the place of breathing and cellular energy with the conversion of glucose to ATP. This process includes several stages of metabolic reactions, including the "Krebs cycle." Mitochondria is the place of breathing and cellular energy with the conversion of glucose to ATP. This process includes several stages of metabolic reactions, including the "Krebs cycle." Mitochondria is the place of breathing and cellular energy with the conversion of glucose to ATP. This process includes several stages of metabolic reactions, including the "Krebs cycle." Measure of the O2 consumption and the mitochondry activity. The extracellular matrix synthesised by fibroblasts contains carbohydrate macromolecules called glycosaminoglycans (GAGs) which are generally covalently linked to a protein to form proteoglycans. These molecules (especially hyaluronic acid) contribute to the suppleness and firmness of the skin by promoting its hydration. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Sebaceous gland sensitivity to androgens relies on the presence of AR in sebocytes. Its presence allows the in vitro model used to be validated and anti-acne products can specifically target this receptor to reduce the amount of sebum produced. Sebaceous gland sensitivity to androgens relies on the presence of AR in sebocytes. Its presence allows the in vitro model used to be validated and anti-acne products can specifically target this receptor to reduce the amount of sebum produced. Sebaceous gland sensitivity to androgens relies on the presence of AR in sebocytes. Its presence allows the in vitro model used to be validated and anti-acne products can specifically target this receptor to reduce the amount of sebum produced. Sebaceous gland sensitivity to androgens relies on the presence of AR in sebocytes. Its presence allows the in vitro model used to be validated and anti-acne products can specifically target this receptor to reduce the amount of sebum produced. Aquaporins correspond to channels facilitating the transfer of water and small molecules across cell membranes. During skin ageing, the decreased expression level of genes coding for aquaporins seems to be correlated with the progressive dehydration of the skin. An anti-ageing product will therefore be able to promote skin hydration by maintaining a greater quantity of aquaporins.Aquaporins correspond to channels facilitating the transfer of water and small molecules across cell membranes. During skin ageing, the decreased expression level of genes coding for aquaporins seems to be correlated with the progressive dehydration of the skin. An anti-ageing product will therefore be able to promote skin hydration by maintaining a greater quantity of aquaporins.Aquaporines correspond to channels facilitating the transfer of water and small molecules across cell membranes. During skin ageing, the decreased expression level of genes coding for aquaporins seems to be correlated with the progressive dehydration of the skin. An anti-ageing product will therefore be able to promote skin hydration by maintaining a greater quantity of aquaporins.Characterisation of the visco-elastic properties of skin with Atomic Force Microscopy.To be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedTo be completedThe blocking capacity of the sweat production of an antiperspirant is measured by studying the interaction between sweat and product. SOD4 and Smart-Pore™ allow us to visualize this phenomenon. Smart-Pore™ is a microfluidic consumable that mimics human sweat pore. SOD4 is a fluid control instrument that mimics sweat production. SOD4 measures in real time the interaction between sweat and the product. It provides information on the kinetics of the formed cap as well as the unblocking pressure required to expel the pore. It is possible to link this unblocking pressure to commercial efficiency claims (24 hours a day). By counting the colonies on agar medium after aerobic incubation, or by checking the absence of bacterial growth after enrichment.Detection on a non-selective liquid of viable microorganisms and the microbial growth inhibitionDetection on a non-selective liquid medium of viable microorganisms and the microbial growth inhibitionDetection on a non-selective liquid medium of viable microorganisms and the microbial growth inhibitionDetection in a non-selective liquid medium of viable microorganisms and the microbial growth inhibition. NF18416. EN18416. ISO18416Genomic methodTo be completedTo be completedTo be completedThe epidermis is a stratified squamous epithelium composed primarily of keratinocytes that undergo sequential changes in gene expression during differentiation. The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that undergo sequential changes in gene expression during differentiation. ColVI exerts different roles in the tissues where it is expressed, spanning from mechanical roles, which are typical of collagen components of the ECM, to more specific cytoprotective functions; these include inhibition of apoptosis and oxidative damage, the regulation of cell differentiation and of the autophagic machinery, and maintenance of cell stemness.ColVI exerts different roles in the tissues where it is expressed, spanning from mechanical roles, which are typical of collagen components of the ECM, to more specific cytoprotective functions; these include inhibition of apoptosis and oxidative damage, the regulation of cell differentiation and of the autophagic machinery, and maintenance of cell stemness.The intercellular lipids are composed of free fatty acids, cholesterol, and ceramides. In conjunction with the other stratum corneum lipids, they form ordered structures. An essential factor is the physical state of the lipid chains in the nonpolar regions of the bilayers.The extracellular matrix synthesised by fibroblasts contains carbohydrate macromolecules called glycosaminoglycans (GAGs) which are generally covalently linked to a protein to form proteoglycans. These molecules (especially hyaluronic acid) contribute to the suppleness and firmness of the skin by promoting its hydration. To be completedNMF is mainly composed of amino acids derived from filaggrin degradation. It is involved in the maintenance of skin hydration, on which the barrier function, the skin suppleness and plasticity, the desquamation process and skin homeostasis depend. During skin aging, the NMF content decreases, thus increasing skin dryness. Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser confocal scanning microscopy (LCSM), is an optical imaging technique for increasing optical resolution and contrast of a micrograph by means of using a spatial pinhole to block out-of-focus light in image formation. AFM analysis of subcutaneous adipoe tissue taken from an explant and cryosection of this tissueAFM analysis of the physical behaviour of fibroblasts coated upon collagen matrix.AFM imaging of newly-formed cell-cell junctions and mechanical measurements of cell junction stiffness and actin cytoskeleton.Mechanical studies of skin's cells and tissues behaviour under external factors, by studying applied forces.Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser confocal scanning microscopy (LCSM), is an optical imaging technique for increasing optical resolution and contrast of a micrograph by means of using a spatial pinhole to block out-of-focus light in image formation.Study with AFM of morphometric parameters of collagen network.Visualisation and characterisation of the lipid matrix within the stratum corneum through skin explants with AFM technology.BioMeca visualizes and characterizes organization of collagen network, strength of cell-matrix interaction and cell traction force by Atomic Force Microscopy.Second-harmonic imaging microscopy (SHIM) is based on a nonlinear optical effect known as second-harmonic generation (SHG). SHIM has been established as a viable microscope imaging contrast mechanism for visualization of cell and tissue structure and function. XPolar® technology is an imaging polarization solution for measuring the birefringence of the samples. The birefringence value is measured in each pixel of the image. The method is based on a non-contact technique that does not cause any degradation in the handling of samples. XPolar® technology is an imaging polarization solution for measuring the birefringence of the samples. The birefringence value is measured in each pixel of the image. The method is based on a non-contact technique that does not cause any degradation in the handling of samples. XPolar® technology is an imaging polarization solution for measuring the birefringence of the samples. The birefringence value is measured in each pixel of the image. The method is based on a non-contact technique that does not cause any degradation in the handling of samples. The principle of the trial is to generate intracellular radical species in a controlled way through an induction photo process based on the use of the orange thiazole (TO). The presence of ROS species leads to cellular alteration and an increase in the level of fluorescence.The assay relies on the stimulation of Nrf2 transcription factor and its binding on the Antioxidant Response Element, an enhancer sequence of many genes coding for antioxidant, detoxification and cytoprotective proteins. The increase of gene expression is measured by luminescence. The assay is based on the intracellular presence of a DNA biosensor whose fluorescence increases in presence of H2O2. Decrease or time delayed increase of fluorescence indicates capacity of sample to neutralize (scavenge) H2O2 in a catalase-like reaction. The LUCS technology is based on photo-induction of Thiazole Orange (TO) leading to a fluorescence signal. A fluorescence increase is only observed on cells in homeostasis prior to TO addition. Calculation of the fluorescence ratios before and after LED application leads to an accurate and dose-dependent measurement of the state of cellular damage that follows chemical or physical toxicity induced by the sample.The different skin flora bacterial strains are pre-grown in appropriate conditions. Bacteria are then re-seeded at low optical density [OD] in order to record bacterial growth on a large window of time, which allow to assess the sample protective effect at the beginning of exponentially growing stage and then for the time needed, at least 4h30.When cells are treated with a radical generator such as 2,2'-azobis (2-amidinopropane) dihydrochloride [AAPH], peroxyl radicals [ROO.] are produced at the plasma membrane level, triggering transformation of intracellular non-fluorescent DCFH into fluorescent dichlorofluorescein [DCF]. Consequently, a decrease in cellular fluorescence in AAPH-treated cells indicates an antioxidant effect of the sample at the level of ROO.s.The Ocular Irritection® Assay System is a standardized, quantitative in vitro test method which utilizes changes of relevant macromolecules to predict the ocular irritancy of chemicals, mixtures and product formulations. Changes in protein structure induced by the test substance can be easily quantified by measuring the resulting changes in turbidity (OD405) of the reagent solution.The Dermal Irritection® Assay System is a standardized, quantitative in vitro test method which utilizes changes of relevant macromolecules to predict the dermal irritancy of chemicals, mixtures and product formulations. Changes in protein structure induced by the test substance can be easily quantified by measuring the resulting changes in turbidity (OD405) of the reagent solution.A glass vial is filled with a chemical detection liquid, coated with a proprietary bio-barrier membrane. The test sample is applied to the membrane. The speed at which it passes through the membrane correlates with its corrosion potential and is revealed by the speed at which the underlying liquid becomes colored. The test substance is placed in the presence of a bacterial suspension and, after a given time, the survival rate of the bacteria is evaluated. The test substance is placed on a surface formed from a bacterial or fungal suspension and, after a given time, the survival rate of the organisms is evaluated.The test substance is placed on a surface formed from a fungal or yeast suspension and, after a given time, the survival rate of the organisms is evaluated. Search for the genetic signatures of plant species and verification of their identity and authenticity using a DNA sequencer using the Sanger sequencing technique.Traceability of plant raw materials and identification of contamination and fraud on ingredients and finished products. Search for the genetic signatures of plant species and verification of their identity and authenticity using a DNA sequencer using the Sanger sequencing technique.In-vitro evaluation on the packaging of the SPF and UVAPF and critical walenlenght with or without pre-irradiation.Measurement of the protection index and of the critical walenlenght under specific conditions of ageing.The substance to test is first placed in the presence of a bacterial suspension and, after a given time, the survival rate of the bacteria is evaluated. Then, this rate is evaluated after application on hands, instruments or surfaces. The fungicide or yeast killer effect of the product is assessed on Candida albicans and Aspergillus brasiliensis under the following conditions: - Hand rubbing (hand scrub) or hygienic hand washing ; - Friction (surgical hand scrub) or surgical hand washing ; - Disinfection of medical equipment.The product to be tested is applied on the hands previously contaminated with Escherichia coli of volunteers. The survival rate of the bacteria is then evaluated and compared to that obtained with a reference product. The product to be tested is applied on the hands previously contaminated with Escherichia coli of volunteers. The survival rate of the bacteria is then evaluated and compared to that obtained with a reference product. Based on the elements of the asset bibliography, the scientific concept and the desired claims, the choice of the tests and assay supports most relevant to objective and/or enhance the effectiveness of the actives ingredients and finished products. From the choice of biomarkers, analysis methods and testing materials, recommendation of the most suitable providers. Review of protocols, follow-up of the study, processing of raw data and interpretation of results.Based on the results of in-vitro or ex-vivo studies and the most relevant results, reflection on innovative concepts, writing scientific media and storytelling.Alternative toxicity assay to Draize Rabbit Eye test. Visual exam. The CAMVA uses the vascularized membrane of fertile chicken eggs to assess a test material's potential to cause vascular changes (hemorraghing, capillary injection, ghost vessels). Resazurin Assay/HistologyThe TRPV1 channel is a well characterized pain receptor that is present in tissues associated with the eye. This channel can be activated by chemical stimuli (or heat) and is thought to be a general mediator of chemically induced pain on the surface of the eye, which can cause a stinging sensation in a clinical setting. This assay predicts the eye stinging potential of materials, such as cosmetics, sunscreens, surfactants, and ophthalmic products. Rather than classify a test material’s irritation potential into discrete regulatory categories, the ET50 screening protocol allows one to determine the irritation potential for materials covering a wide range of irritation responses from highly irritant materials to those which are extremely well tolerated.The amount of absorption is referred to as molar extinction coefficient (MEC)RSMN is used to evaluate the genotoxicity/mutagenicity potential of the test article to the EpiDerm™ Skin Model. Genotoxicity potential is determined by assessing whether the micronucleus frequency in tissues exposed to the test article showed a statistically significant increase relative to the tissues exposed to the solvent (negative) control. This method is based on the comparison of the Sun Protection Factor (SPF) on a dry then a sweat substrate and the calculation of sweat Skin percentage. The in chemico photo-DPRA incorporates a light exposure step into the standard DPRA protocol to determine if a compound becomes photoreactive in the presence of light.This method evaluate photo-cytotoxicity by the relative reduction in viability of cells exposed to the chemical in the presence versus absence of light. Cytotoxicity in this test is expressed as a concentration-dependent reduction of the uptake of the Vital dye Neutral Red (NR) when measured 24 hours after treatment with the test chemical and irradiation. Cell proliferation and differentiation allow to regenerate tissues. At the elderly, the regenerative capacity of the skin decreases, especially because the proportion of stem cells, which are able to multiply, decreases. The suggested methods therefore make it possible to assess the percentage of cells undergoing cell division (dermis and/or epidermis), or the speed at which they multiply. The skin acts as a barrier controlling exchanges between the external environment and the body. This function is maintained by the continuous proliferation and differentiation of keratinocytes. Several markers can be used to determine the differentiation status of keratinocytes. Following a skin lesion, cell migration towards the altered area (keratinocytes, fibroblasts, endothelial cells) allows tissue repair. The speed of healing therefore depends in particular on this migration capacity, which can be measured using various techniques.At the elderly, cell metabolism tends to slow down. At the skin level, this is highlited for example by a decrease in extracellular matrix production by fibroblasts. Various techniques measuring the secretion of molecules (collagen, elastin, etc.) or dosing biosynthesis enzymes make it possible to evaluate the intensity of metabolism. Cell proliferation and differentiation allow to regenerate tissues. At the elderly, the regenerative capacity of the skin decreases, especially because the proportion of stem cells, which are able to multiply, decreases. The suggested methods therefore make it possible to assess the percentage of cells undergoing cell division (dermis and/or epidermis), or the speed at which they multiply. The skin acts as a barrier controlling exchanges between the external environment and the body. This function is maintained by the continuous proliferation and differentiation of keratinocytes. Several markers can be used to determine the differentiation status of keratinocytes. KGF is a growth factor stimulating sebocyte and keratinocyte proliferation and differentiation. In acne-prone skin, overproliferation of keratinocytes and overproduction of sebum related to the proliferation and differentiation of sebocytes are observed. To be completedThe cluster of differentiation 44 (CD44) is on all skin cells. This membrane receptor is involved in cell adhesion and migration, skin inflammation or metastasis, and skin hydration as a key cell receptor for hyaluronic acid.The cluster of differentiation 44 (CD44) is on all skin cells. This membrane receptor is involved in cell adhesion and migration, skin inflammation or metastasis, and skin hydration as a key cell receptor for hyaluronic acid.The intercellular lipids are composed of free fatty acids, cholesterol, and ceramides. In conjunction with the other stratum corneum lipids, they form ordered structures. An essential factor is the physical state of the lipid chains in the nonpolar regions of the bilayers.The intercellular lipids are composed of free fatty acids, cholesterol, and ceramides. In conjunction with the other stratum corneum lipids, they form ordered structures. An essential factor is the physical state of the lipid chains in the nonpolar regions of the bilayers.Certification by a toxicologist that the product is safe for human health when used under normal or reasonably foreseeable conditions of useThe safety is evaluated on the basis of the relevant information according to Annex I of the regulation (EC) n°1223/2009.Compliance with the Part B of the Product Information File (PIF).Literature search. Advice in the choice of tests to be conducted in silico or in vitro to confirm the safety of products. Expertise in formula analysis. Advice in cosmetovigilance.Specific protocol developed by each laboratory. Safety Data Sheets [SDS] gather information on the safety of substances and mixtures and on hazards to the environment and human health, and on safety precautions.Analysis and advice in the valorization of the results of in-vitro or in-vivo evaluation studies.At the elderly, cell metabolism tends to slow down. At the skin level, this is highlited for example by a decrease in extracellular matrix production by fibroblasts. Various techniques measuring the secretion of molecules (collagen, elastin, etc.) or dosing biosynthesis enzymes make it possible to evaluate the intensity of metabolism. Following a skin lesion, cell migration towards the altered area (keratinocytes, fibroblasts, endothelial cells) allows tissue repair. The speed of healing therefore depends in particular on this migration capacity, which can be measured using various techniques.Cell proliferation and differentiation allow to regenerate tissues. At the elderly, the regenerative capacity of the skin decreases, especially because the proportion of stem cells, which are able to multiply, decreases. The suggested methods therefore make it possible to assess the percentage of cells undergoing cell division (dermis and/or epidermis), or the speed at which they multiply. The skin acts as a barrier controlling exchanges between the external environment and the body. This function is maintained by the continuous proliferation and differentiation of keratinocytes. Several markers can be used to determine the differentiation status of keratinocytes. Following a skin lesion, cell migration towards the altered area (keratinocytes, fibroblasts, endothelial cells) allows tissue repair. The speed of healing therefore depends in particular on this migration capacity, which can be measured using various techniques.At the elderly, cell metabolism tends to slow down. At the skin level, this is highlited for example by a decrease in extracellular matrix production by fibroblasts. Various techniques measuring the secretion of molecules (collagen, elastin, etc.) or dosing biosynthesis enzymes make it possible to evaluate the intensity of metabolism. At the elderly, cell metabolism tends to slow down. At the skin level, this is highlited for example by a decrease in extracellular matrix production by fibroblasts. Various techniques measuring the secretion of molecules (collagen, elastin, etc.) or dosing biosynthesis enzymes make it possible to evaluate the intensity of metabolism. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Collagen IV is a major component of the dermal-epidermal junction. It is therefore essential for anchoring the epidermis and maintaining the integrity of the skin barrier. It is also involved in the skin barrier restoration during wound healing and modulates keratinocyte proliferation and differentiation.In acne-prone skin, the IA strain of P. acnes is more abundant and stimulates the production of IGF-1 by keratinocytes. An anti-acne product can reduce this production, which is correlated with keratinocyte proliferation and differentiation.Corneocytes, the final stage of keratinocyte differentiation, are linked together by protein complexes called corneodesmosomes composed of proteins such as corneodesmosin (CDSN), desmoglein 1 (DSG1) and desmocollin 1 (DSC1). Kallikrein 7, capable of cleaving CDSN and DSC1, and kallikrein 5, capable of cleaving CDSN, DSC1 and DSG1, are two proteolytic enzymes involved in the loss of cohesion of corneocytes associated with desquamation. The synthesis and activity of these 2 enzymes must therefore be correctly regulated to ensure desquamation and therefore epidermal renewal at an appropriate level.A film containing various lipids produced by sebaceous glands and keratinocytes covers the skin. Under various factors, including the production of reactive free radicals, skin lipids may be peroxidised. Reactive free radicals also induce cell and tissue damages. A correlation between the level of peroxidised lipids and a defect in wound healing has been reported and an active ingredient may improve skin regeneration or wound healing by decreasing lipid peroxidation. To be completedSLC3A2 is an integrin coreceptor that has been shown to maintain (1) collagen and elastin fiber length and reticulation (2) consequently elastic modulus which gives skin stiffness and (3) a proper TGFbeta location and activation but also (4) sphingolipid metabolism which is involved in mechanosensing signalling. As SLCA3A2 is decreased during skin aging it represents a relevant target to treat aging skin.KN motif and Ankyrin repeat domain containing protein 4 (KANK4) is expressed in papillary fibroblasts at an increased level in both chronologically-aged and photo-damaged skin. Inhibiting this molecule allows to reduce fibroblast contractility which tends to increase with skin aging. Resulting from a mutation of Lamin A protein, Progerin is known to induce a premature aging disease called Progeria. Progerin is also accumulated in skin cells during natural skin aging, thus inducing cell proliferation decrease and cell senescence stimulation. Targeting Progerin may therefore be of great interest to slow down skin aging.TGFβ is involved in various skin processes: epidermis differentiation, extracellular matrix formation and maintenance, wound healing, maintenance of skin-resident immune cells, etc... During skin ageing, the expression level of TGFβ tends to decrease, leading to a greater skin fragility.SLC3A2 is an integrin coreceptor that has been shown to maintain (1) collagen and elastin fiber length and reticulation (2) consequently elastic modulus which gives skin stiffness and (3) a proper TGFbeta location and activation but also (4) sphingolipid metabolism which is involved in mechanosensing signalling. As SLCA3A2 is decreased during skin aging it represents a relevant target to treat aging skin.SLC3A2 is an integrin coreceptor that has been shown to maintain (1) collagen and elastin fiber length and reticulation (2) consequently elastic modulus which gives skin stiffness and (3) a proper TGFbeta location and activation but also (4) sphingolipid metabolism which is involved in mechanosensing signalling. As SLCA3A2 is decreased during skin aging it represents a relevant target to treat aging skin.KN motif and Ankyrin repeat domain containing protein 4 (KANK4) is expressed in papillary fibroblasts at an increased level in both chronologically-aged and photo-damaged skin. Inhibiting this molecule allows to reduce fibroblast contractility which tends to increase with skin aging. KN motif and Ankyrin repeat domain containing protein 4 (KANK4) is expressed in papillary fibroblasts at an increased level in both chronologically-aged and photo-damaged skin. Inhibiting this molecule allows to reduce fibroblast contractility which tends to increase with skin aging. Resulting from a mutation of Lamin A protein, Progerin is known to induce a premature aging disease called Progeria. Progerin is also accumulated in skin cells during natural skin aging, thus inducing cell proliferation decrease and cell senescence stimulation. Targeting Progerin may therefore be of great interest to slow down skin aging.Resulting from a mutation of Lamin A protein, Progerin is known to induce a premature aging disease called Progeria. Progerin is also accumulated in skin cells during natural skin aging, thus inducing cell proliferation decrease and cell senescence stimulation. Targeting Progerin may therefore be of great interest to slow down skin aging.TGFβ is involved in various skin processes: epidermis differentiation, extracellular matrix formation and maintenance, wound healing, maintenance of skin-resident immune cells, etc... During skin ageing, the expression level of TGFβ tends to decrease, leading to a greater skin fragility.TGFβ is involved in various skin processes: epidermis differentiation, extracellular matrix formation and maintenance, wound healing, maintenance of skin-resident immune cells, etc... During skin ageing, the expression level of TGFβ tends to decrease, leading to a greater skin fragility.Keratin 7 (K7) is a well-known marker of sebaceous glands (SG) and sweat glands. In SG, K7-positive cells are progenitor cells located in the periphery of the gland. K7 expression is then lost during sebocyte maturation. As sebum is a holocrine secretion originating from SG cell disintegration into follicular duct of pilosebaceous unit, SG renewal and sebum secretion depend on K7-positive sebocyte proliferation and maturation. In acne-prone skin, these phenomena are simulated, leading to higher sebum production.The cluster of differentiation 44 (CD44) is on all skin cells. This membrane receptor is involved in cell adhesion and migration, skin hydration as a key cell receptor for hyaluronic acid and skin inflammation or metastasis. Permeability barrier disruption and inflammation stimulate epidermal CD44 expression which is involved in leucocyte recruitment and it has been shown that CD44 modulates epidermal proliferation and inflammatory responses in a subacute murine allergic contact dermatitis model. Skin ageing is associated with a decrease in dermal collagen I proportion. This has been correlated to a decrease in procollagen I synthesis and an increase in collagen I degradation by MMP-1. An anti-ageing product can therefore increase Procollagen I synthesis and decrease MMP-1 activity.Skin ageing is associated with an increase in the senescent cell percentage. As senescent human cells overexpress cell growth inhibitors such as p16 and p21, these markers can be used to assess the extent of skin ageing. An anti-ageing product can therefore decrease their expression.Keratin 7 (K7) is a well-known marker of sebaceous glands (SG) and sweat glands. In SG, K7-positive cells are progenitor cells located in the periphery of the gland. K7 expression is then lost during sebocyte maturation. As sebum is a holocrine secretion originating from SG cell disintegration into follicular duct of pilosebaceous unit, SG renewal and sebum secretion depend on K7-positive sebocyte proliferation and maturation. In acne-prone skin, these phenomena are simulated, leading to higher sebum production.Keratin 7 (K7) is a well-known marker of sebaceous glands (SG) and sweat glands. In SG, K7-positive cells are progenitor cells located in the periphery of the gland. K7 expression is then lost during sebocyte maturation. As sebum is a holocrine secretion originating from SG cell disintegration into follicular duct of pilosebaceous unit, SG renewal and sebum secretion depend on K7-positive sebocyte proliferation and maturation. In acne-prone skin, these phenomena are simulated, leading to higher sebum production.Versican is a large extracellular matrix proteoglycan known to bind to elastic fibers and hyaluronan for maintaining the skin hydration and elasticity. Versican V0 isoform expression has been shown to decrease with aging in human dermis. Moreover, Versican size and sulfation pattern are also modified with aging. An anti-aging product can therefore restore an appropriate Versican level and skin elasticity. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. In the suprabasal layers, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. Decreased expression of K1 or K10 may be correlated with a defect in keratinocyte differentiation and impairment of the skin barrier.Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact. Thus, they belong to the "alarmines" whose expression is activated following alteration of the skin barrier, particularly following skin injury, and until the restoration of its functionality.Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratins 15 (K15) is a known marker of basal and bulge stem cells. Consequently, a decrease of K15 expression may be correlated with a decrease of stem cell number, which can lead to reduce the renewal and induce a higher fragility of the skin barrier. Nevertheless, as this marker is also expressed in differentiated cells, a special attention should be paid to the interpretation of K15 expression level and location. Upon skin injury, the expression of keratins 16 / 17 (K16/ K17) and 6 (K6) is stimulated in suprabasal keratinocytes. K17 can combine with K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and protein synthesis. K17 can also induce the production of Th1/Th17 cytokines by keratinocytes, and K17 peptides can serve as self-antigens to promote the activation of antigen-presenting cells and T cells. K17 is thus considered as an alarmine, i.e. a molecules whose expression is activated following injury and which act on the skin barrier by modulating the epidermis structure and the innate immune response. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratin 19 (K19) is a known marker of epidermal stem cells located in both hair follicle and interfollicular areas. Even if its expression in some specific stem cell population is discussed, a decrease of K19 expression may be correlated with a decrease of stem cell number and lead to a more fragile skin barrier. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. In the suprabasal layers, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratins 15 (K15) is a known marker of basal and bulge stem cells. Consequently, a decrease of K15 expression may be correlated with a decrease of stem cell number. Nevertheless, as this marker is also expressed in differentiated cells, a special attention should be paid to the interpretation of K15 expression level and location. During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. K17 can also induce Th1/Th17 cytokine production from keratinocytes, and K17 peptides can also serve as an autoantigen to promote antigen presenting cell (APC)-T cell activation, leading to autoimmune amplification during psoriasis pathogenesis. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratin 19 (K19) is a known marker of epidermal stem cells located in both hair follicle and interfollicular areas. Even if its expression in some specific stem cell population is discussed, a decrease of K19 expression may be correlated with a decrease of stem cell number. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. In the suprabasal layers, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratins 15 (K15) is a known marker of basal and bulge stem cells. Consequently, a decrease of K15 expression may be correlated with a decrease of stem cell number. Nevertheless, as this marker is also expressed in differentiated cells, a special attention should be paid to the interpretation of K15 expression level and location. During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. K17 can also induce Th1/Th17 cytokine production from keratinocytes, and K17 peptides can also serve as an autoantigen to promote antigen presenting cell (APC)-T cell activation, leading to autoimmune amplification during psoriasis pathogenesis. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratin 19 (K19) is a known marker of epidermal stem cells located in both hair follicle and interfollicular areas. Even if its expression in some specific stem cell population is discussed, a decrease of K19 expression may be correlated with a decrease of stem cell number. A decrease in the number of dermal blood vessels is observed during skin aging. This seems to be due to an impairment of Vascular Endothelial Growth Factor (V-EGF) signaling. Some antiaging molecules may restore V-EGF cell level and therefore an appropriate dermal microcirculation. Kruppel-like factor 4 (KLF4) is a transcription factor with dual functions in keratinocytes, being a stemness factor and a pro-differentiation factor. Owing to an increased post-transcriptional expression of Klf4, Klf4 protein decreases during keratinocyte replicative senescence and during physiological skin aging, while its mRNA level does not change. KLF4 is therefore a possible marker of skin aging which may be targeted by antiaging products. Specific analyse developed by each expert. Multicriteria approach with the analysis of biodegradation, acute and chronic aquatic toxicity, bioaccumulation in organisms, endocrine effect, sediment toxicity and terrestrial toxicity.Part A: Cosmetic Product Safety Information. Part B of the CSR is a safety assessment leading to a conclusion on the safety of the product. Literature search. Advice in the choice of tests to be conducted in silico or in vitro to confirm the safety of the ingredients.Interleukin 1 alpha (IL-1α) and bêta (IL-1β) are key pro-inflammatory cytokines released by immune cells such as monocytes and macrophages but also by keratinocytes after their activation or alteration. They are therefore involved in various skin inflammation diseases and constitute appropriate markers of skin inflammatory state. Keratinocytes constitute the interface between the body and the external environment. Various aggressions due to factors such as microorganisms or UV light stimulate these cells and induce the production of TNFα, a cytokine involved in immunity and inflammation. The TNFα assay allows to assess the intensity of the inflammatory response. Epidermal integrity is regulated by a tight communication between keratinocytes and leucocytes, particularly under cytokine control. Imbalance of the cytokine network leads to inflammatory diseases such as psoriasis. The combination of five cytokines (IL-22, Oncostatin M, IL-17, TNFα and IL-1) all overexpressed in vivo in psoriatic lesions has been shown in vitro to induce a “psoriasis-like” epidermis phenotype, both at the histological and molecular levels.Overexpressed in psoriatic lesions, Oncostatin M (OSM) potently regulates the expression of genes involved in skin inflammation and epidermal differentiation. For example, OSM stimulates the expression of antimicrobial peptides and various cytokines such as Th1/Th2 cytokines, whereas it decreases the expression of some epidermal differentiation markers such as K10 or filaggrin. IL-31 belongs to pro-inflammatory cytokines and plays a role in various human inflammatory disorders including atopic dermatitis (AD). Overexpressed in AD lesional skin, IL-31 is produced by TH2 T cells and immature dendritic cells. It can activate various cells including keratinocytes and plays a key role in puritus and pruritic disorders. Interleukin 17 (IL-17) is an essential proinflammatory cytokine secreted by the Th17 cells (CD4+ helper T cells) and subsets of innate lymphoid cells. IL-17 targets many cells including keratinocytes, fibroblasts, neutrophils or endothelial cells and is associated with the pathogenesis of many inflammatory diseases including psoriasis and atopic dermatitis. Interleukin 23 (IL-23) plays a pivotal role in stimulating the production of IL-17 by activating the Th17 cells. IL-17 and IL-23 level may therefore be used as markers of inflammatory state. Interleukin 22 (IL-22) is a cytokine involved in the modulation of tissue responses during inflammation. Produced by Th17 and Th22 T helper cells, IL-22 induces keratinocyte proliferation and epidermal hyperplasia, inhibits terminal differentiation of keratinocytes, and promotes the production of antimicrobial proteins. Th22 cells reside in the normal skin and are enriched in the lesional skin of inflammatory skin diseases. IL-22 plays a role in psoriasis, atopic dermatitis and other inflammatory skin diseases. IFNγ orchestrates numerous protective functions including antigen processing and presentation, leukocyte trafficking, anti-microbial functions, cellular proliferation and apoptosis or the initiation of a cascade of pro-inflammatory responses. Produced by many immune cells including Th1 Tcells, macrophages or dendritic cells (DCs), IFNγ is overexpressed in psoriatic skin and enhances IL-23 and IL-1 production by DCs, leading to Th17 cell activation and initiating psoriasis lesions. On the contrary, its expression is reduced in atopic dermatitis.Interleukin 4 (IL-4) promotes the development of Th2 cells, while interleukin 13 (IL-13) is critical in promoting tissue inflammation. They both play a key role in allergic inflammation and therefore in atopic dermatitis (AD) genesis. In AD, IL-4 and IL-13 are overexpressed and consequently decrease the expression of multiple genes associated with innate defense, including some associated with epidermal differentiation such as filaggrin, therefore impairing epidermal barrier function. IL-6 is a pro-inflammatory cytokine associated with skin healing and inflammation. Released early in response to injury, IL-6 plays a central role in acute inflammation and reparative process occuring successively during wound healing. Overexpressed in skin inflammatory diseases such as psoriasis, IL-6 stimulates both other pro-inflammatory cytokine secretion and keratinocyte hyperproliferation leading to epidermal thickening. IL-6 is produced by immune cells such as lymphocytes, monocyte / macrophages, dendritic cells but also by keratinocytes, fibroblasts, endothelial cells or sebocytes. Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on neutrophils, T cells and basophils. Thus involved in the inflammatory response,especially in the case of bacterial infection, it is locally overproduced in several inflammatory skin diseases involving neutrophilic infiltration, such as psoriasis.Thymic stromal lymphopoietin (TSLP) is a cytokine expressed in allergen stimulated keratinocytes. It plays a key role in allergic inflammation by stimulating eosinophil infiltration and Th2 cytokine secretion (IL-4, IL-5, IL-13) by T helper cells. TSLP can therefore be used as a marker of allergic inflammation. The Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) is a pro-inflammatory cytokine produced by many cell types including keratinocytes activated by hapten, irritant or IL-1a. GM-CSF can be therefore used as an inflammatory response marker in skin following hapten or irritant application. Transforming Growth Factor beta (TGFβ) has many effects highly cell and context-dependent. Among all its effects, TGF-β1 is a potent chemoattractant for endothelial cells and fibroblasts as well as neutrophils and monocytes and stimulates pro-inflammatory cytokine release by these cells. TGF-β overexpression in the epidermal basal layers is also associated with inflammation, keratinocyte hyperproliferation and delayed wound healing. Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. K17 can also induce Th1/Th17 cytokine production from keratinocytes, and K17 peptides can also serve as an autoantigen to promote antigen presenting cell (APC)-T cell activation, leading to autoimmune amplification during psoriasis pathogenesis.Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. K17 can also induce Th1/Th17 cytokine production from keratinocytes, and K17 peptides can also serve as an autoantigen to promote antigen presenting cell (APC)-T cell activation, leading to autoimmune amplification during psoriasis pathogenesis.During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. K17 can also induce Th1/Th17 cytokine production from keratinocytes, and K17 peptides can also serve as an autoantigen to promote antigen presenting cell (APC)-T cell activation, leading to autoimmune amplification during psoriasis pathogenesis.Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.During skin injury, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis.Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. K17 can also induce Th1/Th17 cytokine production from keratinocytes, and K17 peptides can also serve as an autoantigen to promote antigen presenting cell (APC)-T cell activation, leading to autoimmune amplification during psoriasis pathogenesis.Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.Keratins 6 (K6) and 16 (K16) are constitutive keratins of stratified epithelia built up by keratinocytes of relatively high proliferative state such as mucosal tissues, palmoplantar epidermis, and certain skin appendages. Usually absent in interfollicular epidermis of hairy skin, they are rapidly switched on after injury, UV-irradiation and also present in inflammation and some hyperproliferative disorders such as psoriasis. The K16-K6 keratin pair maintains mechanical integrity by increasing cell-cell and cell-matrix contact.During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. K17 can also induce Th1/Th17 cytokine production from keratinocytes, and K17 peptides can also serve as an autoantigen to promote antigen presenting cell (APC)-T cell activation, leading to autoimmune amplification during psoriasis pathogenesis.During skin injury or in psoriasis, suprabasal keratinocytes strongly induce the expression of keratin 16 / 17 (K16/ K17) and 6 (K6). K17 can pair with either K6 or K5 to drive keratinocyte hyperproliferation by increasing cell size and increasing protein synthesis. K17 can also induce Th1/Th17 cytokine production from keratinocytes, and K17 peptides can also serve as an autoantigen to promote antigen presenting cell (APC)-T cell activation, leading to autoimmune amplification during psoriasis pathogenesis.Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratins 15 (K15) is a known marker of basal and bulge stem cells. Consequently, a decrease of K15 expression may be correlated with a decrease of stem cell number. Nevertheless, as this marker is also expressed in differentiated cells, a special attention should be paid to the interpretation of K15 expression level and location. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratins 15 (K15) is a known marker of basal and bulge stem cells. Consequently, a decrease of K15 expression may be correlated with a decrease of stem cell number. Nevertheless, as this marker is also expressed in differentiated cells, a special attention should be paid to the interpretation of K15 expression level and location. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. Keratins 15 (K15) is a known marker of basal and bulge stem cells. Consequently, a decrease of K15 expression may be correlated with a decrease of stem cell number. Nevertheless, as this marker is also expressed in differentiated cells, a special attention should be paid to the interpretation of K15 expression level and location. Phototoxicity (photoirritation) is defined as an acute toxic response elicited by topically or systemically administered photoreactive chemicals after body exposure to environmental light. In OECD 498 test, a chemical is topically applied (at 3 or 5 concentrations) on a reconstructed human epidermis (RhE) in the presence and absence of simulated sunlight (6 J/cm2). After a post-exposure incubation period of 18 to 24 hours, cell viability is determined in both the irradiated and non-irradiated groups by using the MTT test. The more the viability is different between the two groups, the higher the phototoxic potential of the product. Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on neutrophils, T cells and basophils. Thus involved in the inflammatory response,especially in the case of bacterial infection, it is locally overproduced in several inflammatory skin diseases involving neutrophilic infiltration, such as psoriasis.The human ribonuclease RNase 7, which is continuously secreted by keratinocytes, accumulates on the skin surface and has potent antimicrobial activity. It is overexpressed in psoriatic lesions which, on the one hand, stimulates the production of interferon gamma and the triggering of an inflammatory reaction and, on the other hand, limits bacterial superinfections despite the loss of skin barrier integrity. Elafin (SKALP) is mainly produced by epithelial cells and keratinocytes but almost undetectable in normal skin. Its level increases in psoriatic lesions and is enhanced by IL-1 and TNF-alpha (i.e. a pro-inflammatory microenvironment). It inhibits various proteases including elastase and thus protects tissues against the damage caused by pathological acute and chronic inflammation, limits immune response during chronic inflammation and exhibits antimicrobial effects. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.LL37 / hCAP18 is the single known human cathelicidin. It is a small antimicrobial peptide released by neutrophils, macrophages or keratinocytes. Overexpressed in psoriasis, it limits the risk of infection despite a defective skin barrier. In addition to its direct antimicrobial effects, it is also involved in many processes and has been identified as an activating and regulating agent of the inflammatory response characteristic of psoriasis. Psoriasin (S100A7), is an antimicrobial peptide expressed by keratinocytes. It is involved in many functions including inflammation and keratinocyte differentiation. Its synthesis is low in healthy skin but stimulated by IL-22, IL-17 and TNFα in psoriatic lesions, thus participating in inducing the inflammatory response and dysregulating the epidermal differentiation. Psoriasis initiation begins with environmental triggers and/or loss of tolerance, which leads to the activation of several pro-inflammatory dendritic cell populations, including some producing interleukin 23 (IL-23). Under the regulation of IL-23, some T cell populations produce high levels of IL-17 and IL-22 driving inflammatory response and immune cell recruitment, skin thickening and the alteration of keratinocyte proliferation and differentiation. Calcoprotectin (S100A8/9), is a dimer of calgranulin A (S100A8) and B (S100A9) belonging to the antimicrobial peptides produced by keratinocytes. Expressed at low level in healthy skin, it is overexpressed in psoriasis as in other inflammatory diseases or under the action of various stimuli (tape stripping, detergents, UV, interleukins IL-1α and IL-22). Calcoprotectin is involved in inflammatory response, prevents keratinocyte proliferation and induces their differentiation. Koebnerisin S100A15, which has a sequence almost identical to that of psoriasin, is overexpressed in psoriatic skin lesions and known for its antimicrobial, proinflammatory and chemotaxis properties. Caspase 9 is responsible for initiating the caspase activation cascade during apoptosis. In psoriatic lesions, caspase 9 is expressed at a lower level in epidermis compared to normal skin, highlighting a decreased apoptosis in psoriatic epidermis, whereas there are no differences in the dermal perivascular areas. Legal representative by a Responsible Person in a given territory guaranteeing compliance with the requirements of the regulations.The interleukins 4 (IL-4) and 13 (IL-13) are overexpressed in atopic dermatitis (AD). This stimulates inflammation and decreases the expression of multiple genes associated with innate defense, including some associated with epidermal differentiation such as filaggrin, therefore impairing epidermal barrier function. Thus, they both play a key role in atopic dermatitis (AD) genesis.Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on various immune cells. IL-8 is therefore a pro-inflammatory cytokine that is overexpressed in atopic dermatitis (AD) and it has been shown that the concentration of IL-8 in the stratum corneum is closely correlated with the severity of AD. IL-31 belongs to pro-inflammatory cytokines and plays a role in various human inflammatory disorders including atopic dermatitis (AD). Overexpressed in AD lesional skin, IL-31 is produced by TH2 T cells and immature dendritic cells. It can activate various cells including keratinocytes and plays a key role in puritus and pruritic disorders. Derived from the cleavage of profilaggrin coming from granular keratinocytes, filaggrin is a major component of the stratum corneum and actively participates in the skin's barrier function. Atopic dermatitis (AD) is associated with a decrease in filaggrin expression and/or loss of function. This leads to impaired barrier function which facilitates the stratum corneum dehydration, allergen entry and T-cell infiltration. Filaggrin is thus a key player in AD. Claudin-1 is a transmembrane protein which is also the major component of epidermal tight junctions. In atopic dermatitis (AD), a downregulation of Claudin-1 has been associated with tight junction and barrier function impairment. In AD, Claudin-1 decrease also induces inflammation in human epidermis. A new relevant and reliable in vitro method has been developped to allow the evaluation of the Sand Resistance percentage of a sunscreen product by comparing the in vitro SPF before and after a specific agitation in a standardized sand.TNFα is a pro-inflammatory cytokine overexpressed in atopic dermatitis (AD). It acts in synergy with Th2-type cytokines (IL-4, IL-13 and IL-31). It promotes the development of inflammation, in particular by stimulating TSLP expression by keratinocytes, and alters the skin barrier by modulating the synthesis of ceramides and marker proteins for epidermal differentiation. TNFα is a possible target in the treatment of AD.LIGHT (TNSF14) belongs to the tumor necrosis factor (TNF) superfamily overexpressed in atopic dermatitis (AD). This molecule directly stimulates keratinocyte hyperplasia and the production of periostin, a matrix protein, thus contributing to the onset of AD symptoms. This was recently demonstrated in mice. Mainly expressed in suprabasal layers and activated during keratinocyte cornification, Caspase 14 is a protease inducing filaggrin proteolysis. This allows the formation of Natural Moisturizing Factor (NMF) involved in skin hydration. In Atopic Dermatitis (AD), Caspase 14 is decreased, inducing skin dryness. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. In Atopic Dermatitis (AD), its expression is decreased, inducing a more fragile skin barrier. Constantly released by keratinocytes, the human ribonuclease RNase 7 accumulates on the skin surface. It exhibits a potent antimicrobial activity in healthy skin and also exerts potent immunomodulatory activities. In Atopic Dermatitis (AD), RNAse 7 is overexpressed, but its ability to regulate immune response is decreased as well as the ability of keratinocytes to produce RNAse 7 in response to S aureus infection. Interleukin 18 (IL-18) is a pro-inflammatory cytokine produced by keratinocytes and monocytes. It is more abundant in the stratum corneum (SC) of skin with atopic dermatitis (AD) than in healthy skin and its abundance in both SC and blood correlates with the severity of AD. This interleukin stimulates both the Th1 immune response and the production of Th2 type interleukins and histamine by T lymphocytes and mast cells. It thus participates in the genesis of AD and the associated pruritus. Vascular endothelial growth factor (VEGF) is produced by keratinocytes and endothelial cells in skin vessels. A higher level has been observed in the stratum corneum of skins affected by atopic dermatitis than in healthy skins. Moreover, its abundance in both stratum corneum and blood of affected subjects correlates with the severity of atopic dermatitis. Hornerin is a component of cornified cell enveloppes of human epidermis. Its reduced expression in atopic dermatitis contributes to the epidermal barrier defect observed in the disease. Prostaglandin E-2 (PGE-2) is a lipid-derived signalling molecule found in mammalian skin, particularly in fibroblasts. It is overexpressed in atopic skin and stimulates the production of interleukin 22 (IL-22) by T cells. It is thus involved in the genesis of atopic dermatitis, at least in mice. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. In the suprabasal layers, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. The expression of these two keratins is decreased in atopic lesions, probably due to the effect of interleukins 4 and 13. This results in an alteration of the skin barrier. Loricrin and involucrin are two proteins synthesised in the cytoplasm of stratum granulosum keratinocytes. They are markers of terminal differentiation and essential components of the stratum corneum. The expression of these two proteins is decreased in atopic dermatitis and the skin barrier is thus impaired. Human beta-defensin 2 is an antimicrobial peptide produced by keratinocytes when stimulated by microorganisms and/or certain inflammatory cytokines such as IL-1a or TNFa. Its synthesis increases in atopic lesions and its expression level has been correlated with the severity of atopic dermatitis.The interleukins 4 (IL-4) and 13 (IL-13) are overexpressed in atopic dermatitis (AD). This stimulates inflammation and decreases the expression of multiple genes associated with innate defense, including some associated with epidermal differentiation such as filaggrin, therefore impairing epidermal barrier function. Thus, they both play a key role in atopic dermatitis (AD) genesis.The interleukins 4 (IL-4) and 13 (IL-13) are overexpressed in atopic dermatitis (AD). This stimulates inflammation and decreases the expression of multiple genes associated with innate defense, including some associated with epidermal differentiation such as filaggrin, therefore impairing epidermal barrier function. Thus, they both play a key role in atopic dermatitis (AD) genesis.Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on various immune cells. IL-8 is therefore a pro-inflammatory cytokine that is overexpressed in atopic dermatitis (AD) and it has been shown that the concentration of IL-8 in the stratum corneum is closely correlated with the severity of AD. Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on various immune cells. IL-8 is therefore a pro-inflammatory cytokine that is overexpressed in atopic dermatitis (AD) and it has been shown that the concentration of IL-8 in the stratum corneum is closely correlated with the severity of AD. IL-31 belongs to pro-inflammatory cytokines and plays a role in various human inflammatory disorders including atopic dermatitis (AD). Overexpressed in AD lesional skin, IL-31 is produced by TH2 T cells and immature dendritic cells. It can activate various cells including keratinocytes and plays a key role in puritus and pruritic disorders. IL-31 belongs to pro-inflammatory cytokines and plays a role in various human inflammatory disorders including atopic dermatitis (AD). Overexpressed in AD lesional skin, IL-31 is produced by TH2 T cells and immature dendritic cells. It can activate various cells including keratinocytes and plays a key role in puritus and pruritic disorders. Derived from the cleavage of profilaggrin coming from granular keratinocytes, filaggrin is a major component of the stratum corneum and actively participates in the skin's barrier function. Atopic dermatitis (AD) is associated with a decrease in filaggrin expression and/or loss of function. This leads to impaired barrier function which facilitates the stratum corneum dehydration, allergen entry and T-cell infiltration. Filaggrin is thus a key player in AD. Derived from the cleavage of profilaggrin coming from granular keratinocytes, filaggrin is a major component of the stratum corneum and actively participates in the skin's barrier function. Atopic dermatitis (AD) is associated with a decrease in filaggrin expression and/or loss of function. This leads to impaired barrier function which facilitates the stratum corneum dehydration, allergen entry and T-cell infiltration. Filaggrin is thus a key player in AD. Claudin-1 is a transmembrane protein which is also the major component of epidermal tight junctions. In atopic dermatitis (AD), a downregulation of Claudin-1 has been associated with tight junction and barrier function impairment. In AD, Claudin-1 decrease also induces inflammation in human epidermis. Claudin-1 is a transmembrane protein which is also the major component of epidermal tight junctions. In atopic dermatitis (AD), a downregulation of Claudin-1 has been associated with tight junction and barrier function impairment. In AD, Claudin-1 decrease also induces inflammation in human epidermis. TNFα is a pro-inflammatory cytokine overexpressed in atopic dermatitis (AD). It acts in synergy with Th2-type cytokines (IL-4, IL-13 and IL-31). It promotes the development of inflammation, in particular by stimulating TSLP expression by keratinocytes, and alters the skin barrier by modulating the synthesis of ceramides and marker proteins for epidermal differentiation. TNFα is a possible target in the treatment of AD.TNFα is a pro-inflammatory cytokine overexpressed in atopic dermatitis (AD). It acts in synergy with Th2-type cytokines (IL-4, IL-13 and IL-31). It promotes the development of inflammation, in particular by stimulating TSLP expression by keratinocytes, and alters the skin barrier by modulating the synthesis of ceramides and marker proteins for epidermal differentiation. TNFα is a possible target in the treatment of AD.LIGHT (TNSF14) belongs to the tumor necrosis factor (TNF) superfamily overexpressed in atopic dermatitis (AD). This molecule directly stimulates keratinocyte hyperplasia and the production of periostin, a matrix protein, thus contributing to the onset of AD symptoms. This was recently demonstrated in mice. LIGHT (TNSF14) belongs to the tumor necrosis factor (TNF) superfamily overexpressed in atopic dermatitis (AD). This molecule directly stimulates keratinocyte hyperplasia and the production of periostin, a matrix protein, thus contributing to the onset of AD symptoms. This was recently demonstrated in mice. Mainly expressed in suprabasal layers and activated during keratinocyte cornification, Caspase 14 is a protease inducing filaggrin proteolysis. This allows the formation of Natural Moisturizing Factor (NMF) involved in skin hydration. In Atopic Dermatitis (AD), Caspase 14 is decreased, inducing skin dryness. Mainly expressed in suprabasal layers and activated during keratinocyte cornification, Caspase 14 is a protease inducing filaggrin proteolysis. This allows the formation of Natural Moisturizing Factor (NMF) involved in skin hydration. In Atopic Dermatitis (AD), Caspase 14 is decreased, inducing skin dryness. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. In Atopic Dermatitis (AD), its expression is decreased, inducing a more fragile skin barrier. Sirtuin 1 is produced by keratinocytes and, among various functions, is required for skin barrier formation and inflammatory response. Indeed, by stimulating filaggrin expression, it allows appropriate skin cornification. In Atopic Dermatitis (AD), its expression is decreased, inducing a more fragile skin barrier. Constantly released by keratinocytes, the human ribonuclease RNase 7 accumulates on the skin surface. It exhibits a potent antimicrobial activity in healthy skin and also exerts potent immunomodulatory activities. In Atopic Dermatitis (AD), RNAse 7 is overexpressed, but its ability to regulate immune response is decreased as well as the ability of keratinocytes to produce RNAse 7 in response to S aureus infection. Constantly released by keratinocytes, the human ribonuclease RNase 7 accumulates on the skin surface. It exhibits a potent antimicrobial activity in healthy skin and also exerts potent immunomodulatory activities. In Atopic Dermatitis (AD), RNAse 7 is overexpressed, but its ability to regulate immune response is decreased as well as the ability of keratinocytes to produce RNAse 7 in response to S aureus infection. Interleukin 18 (IL-18) is a pro-inflammatory cytokine produced by keratinocytes and monocytes. It is more abundant in the stratum corneum (SC) of skin with atopic dermatitis (AD) than in healthy skin and its abundance in both SC and blood correlates with the severity of AD. This interleukin stimulates both the Th1 immune response and the production of Th2 type interleukins and histamine by T lymphocytes and mast cells. It thus participates in the genesis of AD and the associated pruritus. Interleukin 18 (IL-18) is a pro-inflammatory cytokine produced by keratinocytes and monocytes. It is more abundant in the stratum corneum (SC) of skin with atopic dermatitis (AD) than in healthy skin and its abundance in both SC and blood correlates with the severity of AD. This interleukin stimulates both the Th1 immune response and the production of Th2 type interleukins and histamine by T lymphocytes and mast cells. It thus participates in the genesis of AD and the associated pruritus. Vascular endothelial growth factor (VEGF) is produced by keratinocytes and endothelial cells in skin vessels. A higher level has been observed in the stratum corneum of skins affected by atopic dermatitis than in healthy skins. Moreover, its abundance in both stratum corneum and blood of affected subjects correlates with the severity of atopic dermatitis. Vascular endothelial growth factor (VEGF) is produced by keratinocytes and endothelial cells in skin vessels. A higher level has been observed in the stratum corneum of skins affected by atopic dermatitis than in healthy skins. Moreover, its abundance in both stratum corneum and blood of affected subjects correlates with the severity of atopic dermatitis. Hornerin is a component of cornified cell enveloppes of human epidermis. Its reduced expression in atopic dermatitis contributes to the epidermal barrier defect observed in the disease. Hornerin is a component of cornified cell enveloppes of human epidermis. Its reduced expression in atopic dermatitis contributes to the epidermal barrier defect observed in the disease. Prostaglandin E-2 (PGE-2) is a lipid-derived signalling molecule found in mammalian skin, particularly in fibroblasts. It is overexpressed in atopic skin and stimulates the production of interleukin 22 (IL-22) by T cells. It is thus involved in the genesis of atopic dermatitis, at least in mice. Prostaglandin E-2 (PGE-2) is a lipid-derived signalling molecule found in mammalian skin, particularly in fibroblasts. It is overexpressed in atopic skin and stimulates the production of interleukin 22 (IL-22) by T cells. It is thus involved in the genesis of atopic dermatitis, at least in mice. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. In the suprabasal layers, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. The expression of these two keratins is decreased in atopic lesions, probably due to the effect of interleukins 4 and 13. This results in an alteration of the skin barrier. Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. In the suprabasal layers, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. The expression of these two keratins is decreased in atopic lesions, probably due to the effect of interleukins 4 and 13. This results in an alteration of the skin barrier. Loricrin and involucrin are two proteins synthesised in the cytoplasm of stratum granulosum keratinocytes. They are markers of terminal differentiation and essential components of the stratum corneum. The expression of these two proteins is decreased in atopic dermatitis and the skin barrier is thus impaired. Loricrin and involucrin are two proteins synthesised in the cytoplasm of stratum granulosum keratinocytes. They are markers of terminal differentiation and essential components of the stratum corneum. The expression of these two proteins is decreased in atopic dermatitis and the skin barrier is thus impaired. Human beta-defensin 2 is an antimicrobial peptide produced by keratinocytes when stimulated by microorganisms and/or certain inflammatory cytokines such as IL-1a or TNFa. Its synthesis increases in atopic lesions and its expression level has been correlated with the severity of atopic dermatitis.Human beta-defensin 2 is an antimicrobial peptide produced by keratinocytes when stimulated by microorganisms and/or certain inflammatory cytokines such as IL-1a or TNFa. Its synthesis increases in atopic lesions and its expression level has been correlated with the severity of atopic dermatitis.Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on neutrophils, T cells and basophils. Thus involved in the inflammatory response,especially in the case of bacterial infection, it is locally overproduced in several inflammatory skin diseases involving neutrophilic infiltration, such as psoriasis.Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on neutrophils, T cells and basophils. Thus involved in the inflammatory response,especially in the case of bacterial infection, it is locally overproduced in several inflammatory skin diseases involving neutrophilic infiltration, such as psoriasis.The human ribonuclease RNase 7, which is continuously secreted by keratinocytes, accumulates on the skin surface and has potent antimicrobial activity. It is overexpressed in psoriatic lesions which, on the one hand, stimulates the production of interferon gamma and the triggering of an inflammatory reaction and, on the other hand, limits bacterial superinfections despite the loss of skin barrier integrity. The human ribonuclease RNase 7, which is continuously secreted by keratinocytes, accumulates on the skin surface and has potent antimicrobial activity. It is overexpressed in psoriatic lesions which, on the one hand, stimulates the production of interferon gamma and the triggering of an inflammatory reaction and, on the other hand, limits bacterial superinfections despite the loss of skin barrier integrity. Elafin (SKALP) is mainly produced by epithelial cells and keratinocytes but almost undetectable in normal skin. Its level increases in psoriatic lesions and is enhanced by IL-1 and TNF-alpha (i.e. a pro-inflammatory microenvironment). It inhibits various proteases including elastase and thus protects tissues against the damage caused by pathological acute and chronic inflammation, limits immune response during chronic inflammation and exhibits antimicrobial effects. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.Elafin (SKALP) is mainly produced by epithelial cells and keratinocytes but almost undetectable in normal skin. Its level increases in psoriatic lesions and is enhanced by IL-1 and TNF-alpha (i.e. a pro-inflammatory microenvironment). It inhibits various proteases including elastase and thus protects tissues against the damage caused by pathological acute and chronic inflammation, limits immune response during chronic inflammation and exhibits antimicrobial effects. The analysis of this biomarker is carried out by a specific method whose details will be given to you by the testing laboratory. Please contact them directly.LL37 / hCAP18 is the single known human cathelicidin. It is a small antimicrobial peptide released by neutrophils, macrophages or keratinocytes. Overexpressed in psoriasis, it limits the risk of infection despite a defective skin barrier. In addition to its direct antimicrobial effects, it is also involved in many processes and has been identified as an activating and regulating agent of the inflammatory response characteristic of psoriasis. LL37 / hCAP18 is the single known human cathelicidin. It is a small antimicrobial peptide released by neutrophils, macrophages or keratinocytes. Overexpressed in psoriasis, it limits the risk of infection despite a defective skin barrier. In addition to its direct antimicrobial effects, it is also involved in many processes and has been identified as an activating and regulating agent of the inflammatory response characteristic of psoriasis. Psoriasin (S100A7), is an antimicrobial peptide expressed by keratinocytes. It is involved in many functions including inflammation and keratinocyte differentiation. Its synthesis is low in healthy skin but stimulated by IL-22, IL-17 and TNFα in psoriatic lesions, thus participating in inducing the inflammatory response and dysregulating the epidermal differentiation. Psoriasin (S100A7), is an antimicrobial peptide expressed by keratinocytes. It is involved in many functions including inflammation and keratinocyte differentiation. Its synthesis is low in healthy skin but stimulated by IL-22, IL-17 and TNFα in psoriatic lesions, thus participating in inducing the inflammatory response and dysregulating the epidermal differentiation. Psoriasis initiation begins with environmental triggers and/or loss of tolerance, which leads to the activation of several pro-inflammatory dendritic cell populations, including some producing interleukin 23 (IL-23). Under the regulation of IL-23, some T cell populations produce high levels of IL-17 and IL-22 driving inflammatory response and immune cell recruitment, skin thickening and the alteration of keratinocyte proliferation and differentiation. Psoriasis initiation begins with environmental triggers and/or loss of tolerance, which leads to the activation of several pro-inflammatory dendritic cell populations, including some producing interleukin 23 (IL-23). Under the regulation of IL-23, some T cell populations produce high levels of IL-17 and IL-22 driving inflammatory response and immune cell recruitment, skin thickening and the alteration of keratinocyte proliferation and differentiation. Calcoprotectin (S100A8/9), is a dimer of calgranulin A (S100A8) and B (S100A9) belonging to the antimicrobial peptides produced by keratinocytes. Expressed at low level in healthy skin, it is overexpressed in psoriasis as in other inflammatory diseases or under the action of various stimuli (tape stripping, detergents, UV, interleukins IL-1α and IL-22). Calcoprotectin is involved in inflammatory response, prevents keratinocyte proliferation and induces their differentiation. Calcoprotectin (S100A8/9), is a dimer of calgranulin A (S100A8) and B (S100A9) belonging to the antimicrobial peptides produced by keratinocytes. Expressed at low level in healthy skin, it is overexpressed in psoriasis as in other inflammatory diseases or under the action of various stimuli (tape stripping, detergents, UV, interleukins IL-1α and IL-22). Calcoprotectin is involved in inflammatory response, prevents keratinocyte proliferation and induces their differentiation. Koebnerisin S100A15, which has a sequence almost identical to that of psoriasin, is overexpressed in psoriatic skin lesions and known for its antimicrobial, proinflammatory and chemotaxis properties. Koebnerisin S100A15, which has a sequence almost identical to that of psoriasin, is overexpressed in psoriatic skin lesions and known for its antimicrobial, proinflammatory and chemotaxis properties. Caspase 9 is responsible for initiating the caspase activation cascade during apoptosis. In psoriatic lesions, caspase 9 is expressed at a lower level in epidermis compared to normal skin, highlighting a decreased apoptosis in psoriatic epidermis, whereas there are no differences in the dermal perivascular areas. Caspase 9 is responsible for initiating the caspase activation cascade during apoptosis. In psoriatic lesions, caspase 9 is expressed at a lower level in epidermis compared to normal skin, highlighting a decreased apoptosis in psoriatic epidermis, whereas there are no differences in the dermal perivascular areas. β1-containing integrin dimers are ubiquitously expressed receptor that mediate cell-cell and cell-extracellular matrix interactions. Keratinocytes express α2β1 and α3β1 receptors and β1 has been found to be a marker for proliferation competent cells as its expression decreases during keratinocyte differentiation. β1 plays a key role in the processing of the basement membrane components, including the dermal-epidermal junction, the formation and/or maintenance of hemidesmosomes, and keratinocyte proliferation and differentiation. A defect in β1 expression may therefore impair skin integrity and barrier function. Calprotectin (S100A8/9) is a heterodimer composed of calgranuline A (S100A8) and calgranuline B (S100A9). It is produced by keratinocytes and forms an antimicrobial peptide which limits the development of pathogenic microorganisms, thus participating in skin barrier function. Its expression is low in normal skin but stimulated by various skin stresses such as tape stripping, exposure to detergent, UV, or cytokines (IL-1α, IL-22). Koebnerisin (S100A15) is an antimicrobial peptide produced by keratinocytes with a sequence very similar to psoriasin. Overexpressed in psoriatic lesions or in the case of infection of keratinocytes by Escherischia coli, koebnerisin also has anti-inflammatory and chemotactic properties. It thus contributes to the skin's barrier function. Zonula Occludens 1 (ZO1) is a transmembrane protein linked to the cytosqueleton and providing the structural basis for the assembly of the proteins composing the tight junctions. It therefore participates in the keratinocyte close association and thus in the proper functionning of the skin barrier. Besides this structural function, a role of ZO proteins in the regulation of cell growth and proliferation has also been reported. Transepidermal Water Loss (TEWL) corresponds to the loss of water through the epidermis via diffusion and evaporation processes. TEWL is evaluated by using an evaporimeter and normal rates range from 2.3 g/m2/h to 44 g/m2/h depending on the anatomical region. These values can be increased due to injury, burns, infection or various diseases affecting the stratum corneum. TEWL measurement therefore allows to evaluate skin barrier functionality. Transepithelial/transendothelial electrical resistance (TEER) is a quantitative technique to measure the integrity of tight junction dynamics in cell culture models such as reconstructed human epidermis. TEER values are then strong indicators of the skin barrier integrity. TEER measurements can be performed in real-time without cell damage and generally are based on measuring ohmic resistance or measuring impedance across a wide spectrum of frequencies. This Test method has been designed to provide information on a test substance absorption after its application to the surface of a skin sample separating the two chambers (a donor chamber and a receptor chamber) of a diffusion cell (Franz cell). The substance application should mimic human exposure, normally 1-5 mg/cm2 of skin for a solid and up to 10 µl/cm2 for liquids. Passage kinetics are determined by dosing the active substance at regular intervals in the fluid of the receiving compartment. As the skin is able to metabolize certain substances during percutaneous absorption, the metabolites of the test substance can also be analyzed. In the case of sterile articles packaged in multiple-dose containers, antimicrobial preservatives are added to inhibit the growth of microorganisms that may be introduced from repeatedly withdrawing individual doses. The most widely used method to evaluate the effectiveness of added antimicrobial preservatives to aqueous based products consists in evaluating the effect of those products against 5 representative microorganisms (bacteria, yeast and mold). The microorganism density is commonly evaluated at day (7), 14 and 28. Considering the log reduction of microorganisms obtained from each sampling interval, a product either conforms or does not conform to the USP <51> acceptance criteria.The M-3 method evaluates whether preservatives are effective in limiting contamination of water-miscible cosmetic products. This method has been established as an alternative to the USP <51> testing methodology with more stringent pass/fail criteria. Some personal care products are anhydrous and cannot be sampled using conventional methods. Those include oils, powders and wax-like products. The M-6 method, adapted from the USP <51> method, evaluates whether preservatives are effective in limiting contamination of anhydrous cosmetic products. The M-7 method allows the selection of preservatives that appear to be the most effective in limiting the contamination of a water-miscible cosmetic product. This method saves time in screening but does not replace the M-3 or USP <51> methods for the final validation of a preservative. Type VII collagen (Coll VII) is primarily synthesized by keratinocytes and fibroblasts. It is an anchoring fibril binding Dermal Epidermal Junction (DEJ) proteins such as Laminin 5, 6 or Collagen IV with ExtraCellular Matrix (ECM) proteins of the dermis such as Collagen I, III and V. The quality of the DEJ and the dermis anchoring to the epidermis therefore depends on Coll VII expression level and location.Type XVII collagen (Coll XVII), also called 180-kDa bullous pemphigoid antigen (BP180) is a keratinocyte transmembrane protein located in hemidesmosomes. It binds to other hemidesmosome components such as β4 integrins and plectin, but also to laminin 332 which a component of the Dermal Epidermal Junction (DEJ). The main function of type XVII collagen in skin is therefore to stabilize adhesion of epidermal cells to the DEJ. Skin renewal involves the renewal of the dermal extracellular matrix and in particular of its main component, the collagen I. The density and structure of the collagen I network depend on the synthesis of procollagen I, its assembly into collagen fibrils, the cross-linking of the fibrils and their degradation. A modulation of procollagen I synthesis, observed for example during skin ageing, therefore has consequences for skin renewal and firmness.Kruppel-like factor 4 (KLF4) is a transcription factor with dual functions in keratinocytes, being a stemness factor and a pro-differentiation factor. Owing to an increased post-transcriptional expression of Klf4, Klf4 protein decreases during keratinocyte replicative senescence and during physiological skin aging, while its mRNA level does not change. Modulating the synthesis or post-transcriptional regulation of KLF4 should therefore influence epidermal renewal. A decrease in the number of dermal blood vessels is observed during skin aging. This seems to be due to an impairment of Vascular Endothelial Growth Factor (V-EGF) signaling. Some antiaging molecules may restore V-EGF cell level and therefore an appropriate dermal microcirculation. In addition to its effect on angiogenesis, V-EGF is also involved in maintaining the stemness and renewal abilities of cancer cells in squamous tumours. Versican is a large extracellular matrix proteoglycan known to bind to elastic fibers and hyaluronan for maintaining the skin hydration and elasticity. Versican V0 isoform expression has been shown to decrease with aging in human dermis. Moreover, Versican size and sulfation pattern are also modified with aging. An anti-aging product can therefore restore an appropriate Versican level and skin elasticity.Hornerin is a component of cornified cell enveloppes of human epidermis. Its reduced expression in atopic dermatitis contributes to the epidermal barrier defect observed in the disease. Skin barrier function mainly relies on stratum corneum which is composed of corneocytes embedded in a lipid-enriched lamellar matrix. Rab11a is a GTPase type enzyme highly expressed in terminally differentiated keratinocytes and partly associated with lamellar bodies. Rab11a is involved in lamellar body biogenesis, associated secretion and the production of stratum corneum lipids. Rab11a is therefore essential for skin barrier function. Following pretreatment with a systemic analgesic and instillation of appropriate topical anesthesia, the test chemical (liquid, solid or aerosol) is applied in a single dose to one of the eyes of the experimental animal. The untreated eye serves as the control. The degree of eye irritation/serious eye damage is evaluated by scoring lesions of conjunctiva, cornea, and iris, at specific intervals (at least 1 hour after application and daily for 21 days). Other effects in the eye and adverse systemic effects are also described to provide a complete evaluation of the effects. The duration of the study should be sufficient to evaluate the reversibility or irreversibility of the effects.The objective of OECD 263 is to establish an Integrated Approach on Testing and Assessment (IATA) for hazard identification of serious eye damage and eye irritation potential of test chemicals allowing their classification and labelling according to the United Nations Globally Harmonised System (UN GHS, 2015). Briefly, this guideline suggests to consider first the existing information (human data, in vivo animal data, in vitro animal data, physico-chemical properties and other non testing data) before either taking a conclusive decision regarding classification and labelling (if possible) or formulating a hypothesis which will then guide the sequence of prospective testing. This prospective testing includes 1/ testing on OECD adopted in vitro test methods, 2/ testing on other non-OECD adopted alternative test methods and 3/ As a last resort, testing on in vivo animal test method according to OECD TG 405. The Vitrigel®-EIT method is an in vitro assay using human corneal epithelium (hCE) models fabricated in a collagen vitrigel® membrane chamber. The test chemical is dissolved or suspended in the culture medium before exposure of the hCE model. Immediately after its application, the time-dependent changes in TEER values are registered for a few minutes. When low, the TEER decrease speed and intensity reflect the absence of real damages to the barrier function of the corneal epithelium. In this case, the test chemical is identified as not requiring classification and labelling according to UN GHS (No Category). In this case, no further testing with another test method is considered necessary.The Comet assay is an agarose gel electrophoresis technique. It allows the measurement of breaks induced directly by a genotoxic agent and indirectly during enzymatic damage repair processes or during secondary DNA fragmentation processes such as apoptosis. The formation of micronuclei (MN) is a widely used and accepted endpoint of genotoxicity testing. The MN assay provides a simple and rapid indirect measure of the induction of structural or numerical chromosome aberrations. The hen's egg test for MN induction (HET-MN) is an ex vivo assay for the detection of MN formation in young erythrocytes of chick embryo peripheral blood. Adductomics is the study of DNA adducts in the context of an entire genome. DNA adducts are compounds that bind to DNA, causing damage and mutations. These mutations can result in cancer, aging and birth defects in multicellular organisms. The science of adductomics seeks to identify all DNA adducts and the target sequence of each adduct. Various methods such as for example liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) may allow to detect multiple DNA adducts.The Comet assay is an agarose gel electrophoresis technique. It allows the measurement of breaks induced directly by a genotoxic agent and indirectly during enzymatic damage repair processes or during secondary DNA fragmentation processes such as apoptosis. The 3D Comet assay is an adaptation of this test. It is performed from 3D full thickness human skin models in order to assess the effect of a topical application on keratinocytes and fibroblasts located deeper, as in real-life conditions. Photo-Comet Assay allows to assess the ability of chemical compounds to increase the sensitivity of the skin to radiation (280 - 800nm) through the generation of intermediates and/or reactive oxygen species giving rise to phototoxic or photoallergic reactions. Cell cultures are irradiated with a spectrum covering UVA, UVB and visible wavelengths. Then, DNA damages are evaluated at different time points following irradiation with Comet Assay which allows the measurement of the breaks (single or double strand) induced. Photo-Ames test allows to assess the ability of chemical compounds to increase the frequency of radiation-induced bacterial mutations. Suspensions of bacterial cells are exposed to radiations and the tested substance. They are cultured in the presence and in the absence of an amino-acid which is normally necessary to grow the seeded bacteria (parent strain). Only the revertant bacteria which mutation restore the functional capability of the bacteria to synthesize this essential amino acid are able to grow without the amino-acid. This method allows to assess the mutation frequency under radiation exposure with or without the chemical compound to test, and therefore to determine the potential increase of mutation frequency due to the compound.Loricrin is an insoluble protein that is synthesised and stored as granules in the keratinocytes of the stratum granulosum. It then enters the composition of the stratum corneum where it is linked by covalent bonds to other proteins by transglutaminases. As a major component of the stratum corneum, it represents a marker of the terminal differentiation of the epidermis and plays an essential role in the barrier function, thus limiting water loss and favouring appropriate skin hydration. The h-CLAT method consists of quantifying the variation in the expression of markers such as CD54 or CD86, some cell surface markers involved in the activation of dendritic cells, on cell lines after exposure to sensitising agents. The Photo-hCLAT method is an adaptation of this test performed in the presence or absence of light radiation and with or without the chemical compound to be tested. This allows the effects of the product when placed in the presence of light radiation to be determined and thus the photo-sensitising properties of the product to be assessed.This test consists of detecting estrogen receptor agonists and antagonists (nuclear receptors alpha ERα and/or beta ERβ) via in vitro stable transfection transactivation assays. Luciferase or β-galactosidase reporter genes are used. The cells are placed in the presence of the test substance. If the test substance binds to ERα and/or ERβ, the ligand/receptor complex binds to the ER response element and the reporter gene placed under the control of this response element is transactivated. A system for measuring the level of expression of the protein corresponding to the reporter gene makes it possible to assess the degree of activation of expression by the molecule tested and thus the ability of this molecule to activate ERα and/or ERβ. This assay uses a recombinant human estrogen receptor (ERα) to detect molecules with binding affinity to estrogen receptors. Whether via the Freyberger-Wilson (FW) assay using a full-length human ERα receptor or the Chemical Evaluation and Research Institute (CERI) assay using simply the ligand-binding domain of a human ERα, the principle of the assay is to measure the ability of a radiolabelled ligand ([3H]-17β-estradiol) to bind to ERs in the presence of increasing concentrations of the test chemical (called 'competitor'). The greater the affinity of the competitor for the ER receptor, the more it reduces the ability of the radiolabelled ligand to bind. The measurement of radioactivity after rinsing is therefore a way of assessing the affinity of a test molecule for the oestrogen receptor. Desmogleins and desmocollins are calcium-binding transmembrane glycoproteins belonging to the cadherin superfamily. As components of desmosomes, they are involved in the cohesion between keratinocytes. The exact composition of desmosoms varies depending on the location. For example, Desmoglein 2 is more abundant in the basal layer while Desmoglein 1 level is higher in differentiated keratinocytes. Monitoring the synthesis, abundance and location of all those proteins allow to ensure the correct regeneration of the skin barrier during wound healingKeratins 5 and 14 (K5 and K14) are expressed in dividing keratinocytes in the basal layer of the epidermis. Their expression decreases as the keratinocytes differentiate. K5 and K14 thus make it possible to monitor the re-epithelialisation phase characteristic of wound healing, first by detecting the existence or not of a newly formed epidermis in the injured area and, secondly, by monitoring the proliferation and differentiation of this epidermis. In the suprabasal layers of the epidermis, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. Monitoring the expression of these two keratins during the healing phase allows to visualise the progressive differentiation of the epidermis and the the correct regeneration of the skin barrier. Type VII collagen (Coll VII) is primarily synthesized by keratinocytes and fibroblasts. It is an anchoring fibril binding Dermal Epidermal Junction (DEJ) proteins such as Laminin 5, 6 or Collagen IV with ExtraCellular Matrix (ECM) proteins of the dermis such as Collagen I, III and V. The quality of the DEJ and the dermis anchoring to the epidermis therefore depends on Coll VII expression level and location.Type VII collagen (Coll VII) is primarily synthesized by keratinocytes and fibroblasts. It is an anchoring fibril binding Dermal Epidermal Junction (DEJ) proteins such as Laminin 5, 6 or Collagen IV with ExtraCellular Matrix (ECM) proteins of the dermis such as Collagen I, III and V. The quality of the DEJ and the dermis anchoring to the epidermis therefore depends on Coll VII expression level and location.Type XVII collagen (Coll XVII), also called 180-kDa bullous pemphigoid antigen (BP180) is a keratinocyte transmembrane protein located in hemidesmosomes. It binds to other hemidesmosome components such as β4 integrins and plectin, but also to laminin 332 which a component of the Dermal Epidermal Junction (DEJ). The main function of type XVII collagen in skin is therefore to stabilize adhesion of epidermal cells to the DEJ. Type XVII collagen (Coll XVII), also called 180-kDa bullous pemphigoid antigen (BP180) is a keratinocyte transmembrane protein located in hemidesmosomes. It binds to other hemidesmosome components such as β4 integrins and plectin, but also to laminin 332 which a component of the Dermal Epidermal Junction (DEJ). The main function of type XVII collagen in skin is therefore to stabilize adhesion of epidermal cells to the DEJ. In the suprabasal layers of the epidermis, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. Monitoring the expression of these two keratins during the healing phase allows to visualise the progressive differentiation of the epidermis and the the correct regeneration of the skin barrier. In the suprabasal layers of the epidermis, the differentiation-specific keratins K1 and K10 are expressed. K10 plays a role in proliferation inhibition and, ultrastructurally, keratin filaments composed of the pair K1/K10 form particularly dense bundles that contribute to the mechanical integrity to the cells and the whole epidermis. Monitoring the expression of these two keratins during the healing phase allows to visualise the progressive differentiation of the epidermis and the the correct regeneration of the skin barrier. Interleukin 17 (IL-17) is an essential proinflammatory cytokine secreted by the Th17 cells (CD4+ helper T cells) and subsets of innate lymphoid cells. IL-17 targets many cells including keratinocytes, fibroblasts, neutrophils or endothelial cells and is associated with the pathogenesis of many inflammatory diseases including psoriasis and atopic dermatitis. Interleukin 23 (IL-23) plays a pivotal role in stimulating the production of IL-17 by activating the Th17 cells. IL-17 and IL-23 level may therefore be used as markers of inflammatory state. Interleukin 17 (IL-17) is an essential proinflammatory cytokine secreted by the Th17 cells (CD4+ helper T cells) and subsets of innate lymphoid cells. IL-17 targets many cells including keratinocytes, fibroblasts, neutrophils or endothelial cells and is associated with the pathogenesis of many inflammatory diseases including psoriasis and atopic dermatitis. Interleukin 23 (IL-23) plays a pivotal role in stimulating the production of IL-17 by activating the Th17 cells. IL-17 and IL-23 level may therefore be used as markers of inflammatory state. Interleukin 22 (IL-22) is a cytokine involved in the modulation of tissue responses during inflammation. Produced by Th17 and Th22 T helper cells, IL-22 induces keratinocyte proliferation and epidermal hyperplasia, inhibits terminal differentiation of keratinocytes, and promotes the production of antimicrobial proteins. Th22 cells reside in the normal skin and are enriched in the lesional skin of inflammatory skin diseases. IL-22 plays a role in psoriasis, atopic dermatitis and other inflammatory skin diseases. Interleukin 22 (IL-22) is a cytokine involved in the modulation of tissue responses during inflammation. Produced by Th17 and Th22 T helper cells, IL-22 induces keratinocyte proliferation and epidermal hyperplasia, inhibits terminal differentiation of keratinocytes, and promotes the production of antimicrobial proteins. Th22 cells reside in the normal skin and are enriched in the lesional skin of inflammatory skin diseases. IL-22 plays a role in psoriasis, atopic dermatitis and other inflammatory skin diseases. IL-31 belongs to pro-inflammatory cytokines and plays a role in various human inflammatory disorders including atopic dermatitis (AD). Overexpressed in AD lesional skin, IL-31 is produced by TH2 T cells and immature dendritic cells. It can activate various cells including keratinocytes and plays a key role in puritus and pruritic disorders. IL-31 belongs to pro-inflammatory cytokines and plays a role in various human inflammatory disorders including atopic dermatitis (AD). Overexpressed in AD lesional skin, IL-31 is produced by TH2 T cells and immature dendritic cells. It can activate various cells including keratinocytes and plays a key role in puritus and pruritic disorders. IL-6 is a pro-inflammatory cytokine associated with skin healing and inflammation. Released early in response to injury, IL-6 plays a central role in acute inflammation and reparative process occuring successively during wound healing. Overexpressed in skin inflammatory diseases such as psoriasis, IL-6 stimulates both other pro-inflammatory cytokine secretion and keratinocyte hyperproliferation leading to epidermal thickening. IL-6 is produced by immune cells such as lymphocytes, monocyte / macrophages, dendritic cells but also by keratinocytes, fibroblasts, endothelial cells or sebocytes. IL-6 is a pro-inflammatory cytokine associated with skin healing and inflammation. Released early in response to injury, IL-6 plays a central role in acute inflammation and reparative process occuring successively during wound healing. Overexpressed in skin inflammatory diseases such as psoriasis, IL-6 stimulates both other pro-inflammatory cytokine secretion and keratinocyte hyperproliferation leading to epidermal thickening. IL-6 is produced by immune cells such as lymphocytes, monocyte / macrophages, dendritic cells but also by keratinocytes, fibroblasts, endothelial cells or sebocytes. Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on neutrophils, T cells and basophils. Thus involved in the inflammatory response,especially in the case of bacterial infection, it is locally overproduced in several inflammatory skin diseases involving neutrophilic infiltration, such as psoriasis.Produced by activated monocytes, endothelial cells, keratinocytes, fibroblasts and sebocytes, interleukin 8 (IL-8) exerts a chemotactic effect on neutrophils, T cells and basophils. Thus involved in the inflammatory response,especially in the case of bacterial infection, it is locally overproduced in several inflammatory skin diseases involving neutrophilic infiltration, such as psoriasis.Interleukin 1 alpha (IL-1α) and bêta (IL-1β) are key pro-inflammatory cytokines released by immune cells such as monocytes and macrophages but also by keratinocytes after their activation or alteration. They are therefore involved in various skin inflammation diseases and constitute appropriate markers of skin inflammatory state. Interleukin 1 alpha (IL-1α) and bêta (IL-1β) are key pro-inflammatory cytokines released by immune cells such as monocytes and macrophages but also by keratinocytes after their activation or alteration. They are therefore involved in various skin inflammation diseases and constitute appropriate markers of skin inflammatory state. Interleukin 4 (IL-4) promotes the development of Th2 cells, while interleukin 13 (IL-13) is critical in promoting tissue inflammation. They both play a key role in allergic inflammation and therefore in atopic dermatitis (AD) genesis. In AD, IL-4 and IL-13 are overexpressed and consequently decrease the expression of multiple genes associated with innate defense, including some associated with epidermal differentiation such as filaggrin, therefore impairing epidermal barrier function. Interleukin 4 (IL-4) promotes the development of Th2 cells, while interleukin 13 (IL-13) is critical in promoting tissue inflammation. They both play a key role in allergic inflammation and therefore in atopic dermatitis (AD) genesis. In AD, IL-4 and IL-13 are overexpressed and consequently decrease the expression of multiple genes associated with innate defense, including some associated with epidermal differentiation such as filaggrin, therefore impairing epidermal barrier function. Loricrin is an insoluble protein that is synthesised and stored as granules in the keratinocytes of the stratum granulosum. It then enters the composition of the stratum corneum where it is linked by covalent bonds to other proteins by transglutaminases. As a major component of the stratum corneum, it represents a marker of the terminal differentiation of the epidermis and plays an essential role in the barrier function, thus limiting water loss and favouring appropriate skin hydration. Loricrin is an insoluble protein that is synthesised and stored as granules in the keratinocytes of the stratum granulosum. It then enters the composition of the stratum corneum where it is linked by covalent bonds to other proteins by transglutaminases. As a major component of the stratum corneum, it represents a marker of the terminal differentiation of the epidermis and plays an essential role in the barrier function, thus limiting water loss and favouring appropriate skin hydration.