Expression of inducible and endothelial nitric oxide synthases, formation of peroxynitrite and reactive oxygen species in human chronic renal transplant failure.
Nitric oxide (NO.) is produced by NO synthases (NOS) and can interact with reactive oxygen species (ROS) to form peroxynitrite, which induces protein damage by formation of nitrotyrosine. NO. has a promotional effect on acute rejection. To investigate the role of NO. during chronic renal transplant failure (CRTF), we studied the expression of eNOS and iNOS in conjunction with H2O2 production and the formation of nitrotyrosines. Nephrectomy material from 10 patients and 10 control kidneys was used in this study. Expression of iNOS, eNOS, nitrotyrosine and the presence of ROS-producing cells and macrophages were determined using immunohistochemistry. INOS expression in nonsclerosed glomeruli and interstitium was significantly increased in patients with CRTF (p < 0.05). Glomerular eNOS expression was decreased in patients with CRTF compared with glomeruli of control kidneys (p < 0.01). Nitrotyrosine and ROS positive cells were significantly increased in CRTF in the interstitium (p < 0.05), but not in glomeruli. In summary, we found a marked interstitial increase in iNOS protein expression together with a decrease in glomerular eNOS expression in CRTF patients, associated with a significant increment in ROS and nitrotyrosine-positive cells in the interstitium. Our results suggest that loss of NO. production by glomerular eNOS in conjunction with an increased NO. production by interstitial iNOS, together with the formation of ROS and nitrotyrosine, is involved in the pathogenesis of CRTF.
Departments of Pathology and Nephrology, University Hospital Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands. e.albrecht@path.azg.nl
Ester W J A
EW
Albrecht
Coen A
CA
Stegeman
Anton T M G
AT
Tiebosch
Adam M
AM
Tegzess
Harry
H
van Goor
D000328:Adult; D005260:Female; D006084:Graft Rejection / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007676:Kidney Failure, Chronic / Q000201:enzymology; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D030421:Peroxynitrous Acid / Q000096:biosynthesis*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014184:Transplantation, Homologous; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D017382:Reactive Oxygen Species; D030421:Peroxynitrous Acid; C002744:3-nitrotyrosine; D014443:Tyrosine; C496319:NOS2 protein, human; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III