Open AccessRenoprotection by statins is linked to a decrease in renal oxidative stress, TGF-β, and fibronectin with concomitant increase in nitric oxide bioavailability
Author(s) -
Ming Zhou,
Ivonne Hernandez Schuman,
Edgar A. Jaimes,
Leopoldo Raij
Publication year - 2008
Publication title -
american journal of physiology. renal physiology./american journal of physiology. renal physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.335
H-Index - 169
eISSN - 1931-857X
pISSN - 1522-1466
DOI - 10.1152/ajprenal.00041.2008
Subject(s) - endocrinology , medicine , oxidative stress , chemistry , glomerulosclerosis , nadph oxidase , nitric oxide , enos , proinflammatory cytokine , proteinuria , nitric oxide synthase , kidney , inflammation
Clinical and experimental studies have provided evidence suggesting that statins exert renoprotective effects. To investigate the mechanisms by which statins may exert renoprotection, we utilized the hypertensive Dahl salt-sensitive (DS) rat model, which manifests cardiovascular and renal injury linked to increased angiotensin II-dependent activation of NADPH oxidase and decreased nitric oxide (NO) bioavailability. DS rats given high salt diet (4% NaCl) for 10 wk exhibited hypertension [systolic blood pressure (SBP) 200 +/- 8 vs. 150 +/- 2 mmHg in normal salt diet (0.5% NaCl), P < 0.05], glomerulosclerosis, and proteinuria (158%). This was associated with increased renal oxidative stress demonstrated by urinary 8-F(2alpha)-isoprostane excretion and NADPH oxidase activity, increased protein expression of transforming growth factor (TGF)-beta (63%) and fibronectin (181%), increased mRNA expression of the proinflammatory molecules monocyte chemoattractant protein-1 (MCP-1) and lectin-like oxidized LDL receptor-1 (LOX-1), as well as downregulation of endothelial NO synthase (eNOS) activity (-44%) and protein expression. Return to normal salt had no effect on SBP or any of the measured parameters. Atorvastatin (30 mg.kg(-1).day(-1)) significantly attenuated proteinuria and glomerulosclerosis and normalized renal oxidative stress, TGF-beta1, fibronectin, MCP-1 and LOX-1 expression, and eNOS activity and expression. Atorvastatin-treated rats showed a modest reduction in SBP that remained in the hypertensive range (174 +/- 8 mmHg). Atorvastatin combined with removal of high salt normalized SBP and proteinuria. These findings suggest that statins mitigate hypertensive renal injury by restoring the balance among NO, TGF-beta1, and oxidative stress and explain the added renoprotective effects observed in clinical studies using statins in addition to inhibitors of the renin-angiotensin system.