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BASIS FOR ENHANCED BARRIER FUNCTION OF PIGMENTED SKIN

Humans with darkly-pigmented skin display superior permeability barrier function in comparison to humans with lightly-pigmented skin. The reduced pH of the stratum corneum (SC) of darkly-pigmented skin could account for enhanced function, because acidifying lightly-pigmented human SC resets barrier...

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Detalles Bibliográficos
Autores principales: Man, Mao-Qiang, Lin, Tzu-Kai, Santiago, Juan Luis, Celli, Anna, Zhong, Lily, Huang, Zhi-Ming, Roelandt, Truus, Hupe, Melanie, Sundberg, John P., Silva, Kathleen A., Crumrine, Debra, Martin-Ezquerra, Gemma, Trullas, Carles, Sun, Richard, Wakefield, Joan S., Wei, Maria L., Feingold, Kenneth R., Mauro, Theodora M., Elias, Peter M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4134407/
https://www.ncbi.nlm.nih.gov/pubmed/24732399
http://dx.doi.org/10.1038/jid.2014.187
Descripción
Sumario:Humans with darkly-pigmented skin display superior permeability barrier function in comparison to humans with lightly-pigmented skin. The reduced pH of the stratum corneum (SC) of darkly-pigmented skin could account for enhanced function, because acidifying lightly-pigmented human SC resets barrier function to darkly-pigmented levels. In SKH1 (non-pigmented) vs. SKH2/J (pigmented) hairless mice, we evaluated how a pigment-dependent reduction in pH could influence epidermal barrier function. Permeability barrier homeostasis is enhanced in SKH2/J vs. SKH1 mice, correlating with a reduced pH in the lower SC that co-localizes with the extrusion of melanin granules. Darkly-pigmented human epidermis also shows substantial melanin extrusion in the outer epidermis. Both acute barrier disruption and topical basic pH challenges accelerate re-acidification of SKH2/J (but not SKH1) SC, while inducing melanin extrusion. SKH2/J mice also display enhanced expression of the SC acidifying enzyme, secretory phospholipase A2f (sPLA2f). Enhanced barrier function of SKH2/J mice could be attributed to enhanced activity of two acidic pH-dependent, ceramide-generating enzymes, β-glucocerebrosidase and acidic sphingomyelinase, leading to accelerated maturation of SC lamellar bilayers. Finally, organotypic cultures of darkly-pigmented-bearing human keratinocytes display enhanced barrier function in comparison to lightly-pigmented cultures. Together, these results suggest that the superior barrier function of pigmented epidermis can be largely attributed to the pH-lowering impact of melanin persistence/extrusion and enhanced sPLA2f expression.