Oxidative DNA damage and tubulointerstitial injury in diabetic nephropathy.
BACKGROUND
Oxidative stress is an important pathogenetic factor in underlying diabetic complications. Recently, 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been reported to serve as a new sensitive biomarker of the oxidative DNA damage in vivo. We studied the relationship between oxidative DNA damage and tubulointerstitial injury in patients with diabetic nephropathy.


METHODS
Type 2 diabetic patients (n = 25) and healthy control subjects (n = 20) were studied. The urine concentrations of 8-OHdG were measured by a competitive ELISA. The severity of the glomerular changes was graded using Gellman's criteria, and the severity of the tubulointerstitial lesions was determined by a semiquantitative estimate of the space occupied by the fibrous tissue and/or interstitial infiltrates.


RESULTS
The urinary 8-OHdG excretion were significantly higher in the diabetics than in the healthy controls, and tended to increase with severity of the glomerular diffuse lesion, but it was not significant. The urinary 8-OHdG excretion significantly increased with severity of the tubulointerstitial lesion.


CONCLUSIONS
Oxidative stress may contribute to the progression of tubulointerstitial injury in patients with diabetic nephropathy.
Kanauchi
Masao
M
First Department of Internal Medicine, Nara Medical University, Kashihara, Japan. kanauchi@nmu-gw.naramed-u.ac.jp
Nishioka
Hisayuki
H
Hashimoto
Toshio
T
D000080242:8-Hydroxy-2'-Deoxyguanosine; D015415:Biomarkers; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000652:urine; D003928:Diabetic Nephropathies / Q000175:diagnosis* / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000175:diagnosis / Q000378:metabolism; D018384:Oxidative Stress
D015415:Biomarkers; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine