title: Localization and expression of cornifin-alpha/SPRR1 in mouse epidermis, anagen hair follicles, and skin neoplasms.
abstract: Recently, cornifin-alpha/SPPR1 has been identified as a putative precursor protein of the cornified cell envelope. In this study, the expression and localization of cornifin-alpha/SPPR1 was examined in untreated and tumor promoter-treated mouse skin, hair follicles, and skin neoplasms. Western analysis with antiserum (SQ37A) to a rabbit cornifin-alpha peptide or antiserum (SQ37C) to a human SPRR1 peptide demonstrated a 31-kDa immunoreactive protein in mouse epidermis and Northern analysis revealed the presence of a 1-kb mRNA. Immunohistochemical staining of mouse skin with SQ37A or SQ37C revealed intense and specific staining of the infundibulum, isthmus, and of Henle's layer of the inner root sheath of the lower anagen hair follicle and weak staining of the telogen follicle and the suprabasal layers of the epidermis. Treatment of mouse skin with 12-0-tetradecanoyl-phorbol-13-acetate (TPA) produced a large increase in cornifin-alpha/SPRR1 protein and mRNA. Immunohistochemical localization of cornifin-alpha/SPRR1 in TPA-treated skin indicated that cornifin-alpha/SPRR1 was increased in the suprabasal epidermis but not in the follicle. sn-1,2,-didecanoylglycerol, a model lipid second messenger, produced an increase in cornifin-alpha/SPRR1 protein similar to that of TPA, while mirex, a non-phorbol ester-type promoter had no effect. Topical doses of retinoic acid did not repress TPA-induced cornifin-alpha/SPRR1 expression. Papillomas demonstrated a 10- and 100-fold increase in cornifin-alpha/SPRR1 protein and mRNA, and expression was restricted to suprabasal cells. Squamous cell carcinomas exhibited an intermediate level of cornifin-alpha protein, and expression was restricted to keratinized areas. These data indicate: i) cornifin-alpha/SPRR1 is expressed in mouse skin; ii) cornifin-alpha/SPRR1 is localized to specific areas of the anagen hair follicle with weak staining in the telogen follicle and epidermis; iii) epidermal cornifin-alpha/SPRR1 expression is induced by phorbol ester and sn-1,2-didecanoylglycerol but not mirex, and iv) papillomas and squamous cell carcinomas demonstrate a constitutive increase in cornifin-alpha/SPRR1 in differentiated areas of the neoplasms.
authors.affiliation: Department of Toxicology, North Carolina State University, Raleigh, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Owens
authors.forename: T A
authors.initials: TA
authors.lastname: Zainal
authors.forename: A M
authors.initials: AM
authors.lastname: Jetten
authors.forename: R C
authors.initials: RC
authors.lastname: Smart
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000737:chemistry; D055233:Cornified Envelope Proline-Rich Proteins; D004817:Epidermis / Q000737:chemistry*; D005260:Female; D018859:Hair Follicle / Q000737:chemistry*; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics; D051379:Mice; D008917:Mirex / Q000494:pharmacology; D010212:Papilloma / Q000139:chemically induced / Q000737:chemistry; D011506:Proteins / Q000032:analysis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012878:Skin Neoplasms / Q000737:chemistry*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D055233:Cornified Envelope Proline-Rich Proteins; D008565:Membrane Proteins; D011506:Proteins; D012333:RNA, Messenger; D013755:Tetradecanoylphorbol Acetate; D008917:Mirex