title: Lipid deregulation in UV irradiated skin cells: Role of 25-hydroxycholesterol in keratinocyte differentiation during photoaging.
abstract: Skin photoaging due to UV irradiation is a degenerative process that appears more and more as a growing concern. Lipids, including oxysterols, are involved in degenerative processes; as skin cells contain various lipids, the aim of our study was to evaluate first, changes in keratinocyte lipid levels induced by UV exposure and second, cellular effects of oxysterols in cell morphology and several hallmarks of keratinocyte differentiation. Our mass spectrometry results demonstrated that UV irradiation induces changes in lipid profile of cultured keratinocytes; in particular, ceramides and oxysterols, specifically 25-hydroxycholesterol (25-OH), were increased. Using holography and confocal microscopy analyses, we highlighted cell thickening and cytoskeletal disruption after incubation of keratinocytes with 25-OH. These alterations were associated with keratinocyte differentiation patterns: autophagy stimulation and intracellular calcium increase as measured by cytofluorometry, and increased involucrin level detected by immunocytochemistry. To conclude, oxysterol deregulation could be considered as a common marker of degenerative disorders. During photoaging, 25-OH seems to play a key role inducing morphological changes and keratinocyte differentiation.
authors.affiliation: UMR CNRS 8638-Chimie Toxicologie Analytique et Cellulaire, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie de Paris, 4 Avenue de l'Observatoire, 75006 Paris, France; Soliance-Givaudan, Route de Bazancourt, 51110 Pomacle, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Olivier
authors.affiliation: UMR CNRS 8638-Chimie Toxicologie Analytique et Cellulaire, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie de Paris, 4 Avenue de l'Observatoire, 75006 Paris, France; Recherche et Développement, Laboratoire d'Evaluation Physiologique, Yslab, 2 rue Félix le Dantec, 29000 Quimper, France.
authors.forename: Mélody
authors.initials: M
authors.lastname: Dutot
authors.affiliation: UMR CNRS 8638-Chimie Toxicologie Analytique et Cellulaire, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie de Paris, 4 Avenue de l'Observatoire, 75006 Paris, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Regazzetti
authors.affiliation: UMR CNRS 8638-Chimie Toxicologie Analytique et Cellulaire, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie de Paris, 4 Avenue de l'Observatoire, 75006 Paris, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Dargère
authors.affiliation: UMR CNRS 8638-Chimie Toxicologie Analytique et Cellulaire, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie de Paris, 4 Avenue de l'Observatoire, 75006 Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Auzeil
authors.affiliation: UMR CNRS 8638-Chimie Toxicologie Analytique et Cellulaire, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie de Paris, 4 Avenue de l'Observatoire, 75006 Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Laprévote
authors.affiliation: UMR CNRS 8638-Chimie Toxicologie Analytique et Cellulaire, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie de Paris, 4 Avenue de l'Observatoire, 75006 Paris, France. Electronic address: patrice.rat@parisdescartes.fr.
authors.forename: Patrice
authors.initials: P
authors.lastname: Rat
mesh_terms: D001343:Autophagy; D002454:Cell Differentiation; D002460:Cell Line; D002470:Cell Survival; D002518:Ceramides / Q000737:chemistry; D003470:Culture Media; D003599:Cytoskeleton / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D006888:Hydroxycholesterols / Q000737:chemistry*; D015603:Keratinocytes / Q000166:cytology* / Q000528:radiation effects; D008027:Light; D008055:Lipids / Q000737:chemistry*; D018613:Microscopy, Confocal; D009336:Necrosis; D000072376:Oxysterols / Q000737:chemistry; D011498:Protein Precursors / Q000737:chemistry; D012867:Skin / Q000166:cytology*; D015595:Skin Aging; D014466:Ultraviolet Rays
chemical_list: D002518:Ceramides; D003470:Culture Media; D006888:Hydroxycholesterols; D008055:Lipids; D000072376:Oxysterols; D011498:Protein Precursors; C032253:involucrin; C007997:25-hydroxycholesterol
keywords: Cell morphology; Keratinocyte differentiation; Oxysterol; Photoaging; Skin