Nitrotyrosine formation and apoptosis in rat models of ocular injury.
This study was performed to examine inducible nitric oxide synthase (NOS-2) expression, nitrotyrosine formation and apoptosis in rats with elevated intraocular pressure (IOP) and/or ocular inflammation. Ocular inflammation was induced via injection of intra-vitreal lipopolysaccharide (LPS) while IOP was elevated by episcleral vessel cauterization. Animals were randomized to one of the following conditions: elevated IOP, LPS, elevated IOP+LPS, and control. Immunohistochemical staining and western blot analysis of retinal lysates revealed NOS-2 and nitrotyrosine immunoreactivity in all disease groups. NOS-2 expression and protein nitration was significantly greater in rats with elevated IOP+LPS compared to elevated IOP, LPS, and control groups. Nitrite levels in the retina affirmed significantly increased levels of nitric oxide generation in LPS-treated rats with elevated IOP (346+/-23.8 microM) vs LPS-treated, elevated IOP and control groups (195.6+/-12.6, 130+/-2.5 and 76.6+/-15.6 microM, respectively). Retinal TUNEL staining showed apoptosis in all diseased groups. Percent of apoptotic cells was significantly greater in the elevated IOP+LPS group compared to LPS-treated or elevated IOP groups. Presented data illustrates that both elevated IOP and ocular inflammation augment NOS-2 expression, retinal protein nitration and apoptosis in rats.
Aslan
Mutay
M
Akdeniz University Medical School, Department of Biochemistry, Antalya, 07070, Turkey. mutayaslan@akdeniz.edu.tr
Yücel
Iclal
I
Akar
Yusuf
Y
Yücel
Gültekin
G
Ciftçioğlu
M Akif
MA
Sanlioglu
Salih
S
D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D005131:Eye Injuries / Q000378:metabolism* / Q000473:pathology; D020287:In Situ Nick-End Labeling; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D023421:Models, Animal; D009566:Nitrates / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D008070:Lipopolysaccharides; D009566:Nitrates; D009573:Nitrites; C002744:3-nitrotyrosine; D014443:Tyrosine; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat