Elsevier

Kidney International

Volume 58, Issue 3, September 2000, Pages 1174-1185
Kidney International

Cell Biology – Immunology – Pathology
Effect of nitric oxide modulation on TGF-β1 and matrix proteins in chronic cyclosporine nephrotoxicity

https://doi.org/10.1046/j.1523-1755.2000.00273.xGet rights and content
Under an Elsevier user license
open archive

Effect of nitric oxide modulation on TGF-β1 and matrix proteins in chronic cyclosporine nephrotoxicity.

Background

Chronic cyclosporine (CsA) nephrotoxicity is characterized by interstitial fibrosis and afferent arteriolar hyalinosis. L-arginine (L-Arg), the substrate for nitric oxide (NO) synthase and N-nitro-L-arginine-methyl ester (L-NAME), the NO synthase inhibitor, were shown to modulate acute CsA nephrotoxicity. However, the mechanism of fibrosis in chronic CsA nephrotoxicity remains unclear. Thus, we examined the effect of NO modulation on fibrosis and the expression of transforming growth factor-β1 (TGF-β1) and matrix proteins in chronic CsA nephrotoxicity.

Methods

Rats were administered CsA (7.5 mg/kg), CsA + L-Arg (1.7 g/kg), CsA + L-NAME (3.5 mg/kg), vehicle (VH), VH + L-Arg, and VH + L-NAME, and were sacrificed at 7 or 28 days. NO production, physiologic parameters, and histology were studied in addition to the mRNA expression of TGF-β1, plasminogen activator inhibitor-1 (PAI-1) and the matrix proteins biglycan and collagens type I and IV by Northern and the protein expression of PAI-1 and fibronectin by enzyme-linked immunosorbent assay.

Results

While L-NAME strikingly reduced NO biosynthesis and worsened the glomerular filtration rate and CsA-induced fibrosis, L-Arg had the opposite beneficial effect. In addition, the CsA-induced up-regulated expression of TGF-β1, PAI-1, and the matrix proteins biglycan, fibronectin, and collagen I was significantly increased with L-NAME and strikingly improved with L-Arg. Collagen IV expression was not affected. Also, NO modulation did not affect VH-treated rats.

Conclusions

Chronic CsA nephrotoxicity can be aggravated by NO blockade and ameliorated by NO enhancement, suggesting that NO maintains a protective function. NO modulation was associated with a change in TGF-β1 expression, which, in turn, was associated with alterations in matrix deposition and matrix degradation through its effect on PAI-1.

Keywords

collagen
extracellular matrix
fibrosis
glycoprotein
L-arginine
plasminogen activator inhibitor-1
afferent arteriolar hyalinosis

Cited by (0)