title: Corticosteroids enhance S-antigen expression in nonretinal ocular tissues of rats with experimental autoimmune uveitis.
abstract: S-antigen (S-Ag), a major protein on the retinal photoreceptor cell, can induce experimental autoimmune uveitis (EAU). We have previously detected S-Ag and its mRNA in irises of chronic uveitis patients receiving long-term steroid therapy. To further investigate the effect of steroid therapy on ocular tissue, we compared levels of S-Ag and its mRNA in EAU rats with and without steroid treatment. EAU was induced in 72 Lewis rats by two footpad injections of S-Ag. The rats were then treated with Depo-Medrol or phosphate-buffered saline by intramuscular injection. Eyes were collected at different time points. S-Ag mRNA was detected in the lens epithelium, trabecular meshwork, iris, and ciliary body of 47.2% of the steroid-treated group vs 22.2% of the controls. S-antigen was also detected in 30.6% of the eyes of the treated group vs 16.7% of the controls. S-Ag and its mRNA was found only in the retina of normal rats. These results support the hypothesis that prolonged corticosteroid therapy in uveitic patients might enhance the expression of S-Ag in nonretinal ocular tissues and might contribute to the ocular side effects of corticosteroid.
authors.affiliation: Laboratory of Immunology, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.forename: T
authors.initials: T
authors.lastname: Abe
authors.forename: T
authors.initials: T
authors.lastname: Kikuchi
authors.forename: R B
authors.initials: RB
authors.lastname: Nussenblatt
authors.forename: T
authors.initials: T
authors.lastname: Shinohara
authors.forename: C C
authors.initials: CC
authors.lastname: Chan
mesh_terms: D000818:Animals; D000941:Antigens / Q000096:biosynthesis*; D019393:Arrestin; D002924:Ciliary Body / Q000378:metabolism; D005136:Eye Proteins / Q000096:biosynthesis*; D005260:Female; D017403:In Situ Hybridization; D007908:Lens, Crystalline / Q000378:metabolism; D008775:Methylprednisolone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000077555:Methylprednisolone Acetate; D051381:Rats; D011917:Rats, Inbred Lew; D014129:Trabecular Meshwork / Q000378:metabolism; D014605:Uveitis / Q000276:immunology / Q000378:metabolism*
chemical_list: D000941:Antigens; D019393:Arrestin; D005136:Eye Proteins; D000077555:Methylprednisolone Acetate; D008775:Methylprednisolone