Stimulation of macrophage function by interphotoreceptor retinoid-binding protein: production of nitric oxide.
In this study, we investigated whether retinal soluble proteins, such as interphotoreceptor retinoid-binding protein(IRBP), play a role in the induction of nitric oxide by macrophages in vitro. Cells from the murine macrophage cell line RAW 264.7 and rat and rabbit peritoneal macrophages were incubated in the presence of retinal soluble protein. The nitrite level in the cultured supernatant was evaluated for nitric oxide production using the Griess reaction. IRBP induced significant, dose-dependent nitrite production in both RAW 264.7 and rat peritoneal macrophages. Induction of inducible nitric oxide synthase (iNOS) by retinal proteins was inhibited by the iNOS-specific inhibitor, aminoguanidine, and the tyrosine inhibitor, genistein. These results show that soluble retinal proteins significantly induce nitric acid production by macrophages. Increased production of reactive oxygen species by macrophages in the presence of this soluble retinal protein in vivo may accelerate photoreceptor degeneration in uveitis.
Bae
S R
SR
Department of Ophthalmology, Taejon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Korea.
D000818:Animals; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005136:Eye Proteins / Q000494:pharmacology*; D006146:Guanidines / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D011817:Rabbits; D051381:Rats; D011917:Rats, Inbred Lew; D012177:Retinol-Binding Proteins / Q000494:pharmacology*; D000099214:Retinol-Binding Proteins, Interstitial
D004791:Enzyme Inhibitors; D005136:Eye Proteins; D006146:Guanidines; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D012177:Retinol-Binding Proteins; D000099214:Retinol-Binding Proteins, Interstitial; C496318:Nos2 protein, rat; C004479:pimagedine