title: Endogenous Retinoic Acid Required to Maintain the Epidermis Following Ultraviolet Light Exposure in SKH-1 Hairless Mice.
abstract: Ultraviolet light B (UVB) exposure induces cutaneous squamous cell carcinoma (cSCC), one of the most prevalent human cancers. Reoccurrence of cSCC in high-risk patients is prevented by oral retinoids. But oral retinoid treatment causes significant side effects; and patients develop retinoid resistance. Exactly how retinoids prevent UVB-induced cSCC is currently not well understood. Retinoid resistance blocks mechanistic studies in the leading mouse model of cSCC, the UVB-exposed SKH-1 hairless mouse. To begin to understand the role of retinoids in UVB-induced cSCC we first examined the localization pattern of key retinoid metabolism proteins by immunohistochemistry 48 h after UVB treatment of female SKH-1 mice. We next inhibited retinoic acid (RA) synthesis immediately after UVB exposure. Acute UVB increased RA synthesis, signaling and degradation proteins in the stratum granulosum. Some of these proteins changed their localization; while other proteins just increased in intensity. In contrast, acute UVB reduced the retinoid storage protein lectin:retinol acyltransferase (LRAT) in the epidermis. Inhibiting RA synthesis disrupted the epidermis and impaired differentiation. These data suggest that repair of the epidermis after acute UVB exposure requires endogenous RA synthesis.
authors.affiliation: Department of Human Sciences (Nutrition), the Ohio State University, Columbus, OH.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Gressel
authors.affiliation: Department of Human Sciences (Nutrition), the Ohio State University, Columbus, OH.
authors.forename: F Jason
authors.initials: FJ
authors.lastname: Duncan
authors.affiliation: Department of Pathology, the Ohio State University, Columbus, OH.
authors.forename: Tatiana M
authors.initials: TM
authors.lastname: Oberyszyn
authors.affiliation: Department of Veterinary Biosciences, the Ohio State University, Columbus, OH.
authors.forename: Krista M
authors.initials: KM
authors.lastname: La Perle
authors.affiliation: Department of Human Sciences (Nutrition), the Ohio State University, Columbus, OH.
authors.forename: Helen B
authors.initials: HB
authors.lastname: Everts
mesh_terms: D000818:Animals; D004817:Epidermis / Q000473:pathology* / Q000528:radiation effects; D005260:Female; D051379:Mice; D008812:Mice, Hairless; D014212:Tretinoin / Q000502:physiology*; D014466:Ultraviolet Rays
chemical_list: D014212:Tretinoin