3-Hydroxy-3-methylglutaryl CoA reductase inhibitors prevent high glucose-induced proliferation of mesangial cells via modulation of Rho GTPase/p21 signaling pathway: Implications for diabetic nephropathy

Farhad R. Danesh, Mehran M. Sadeghit, Nail Amro, Carrie Philips, Lixia Zeng, Sun Lin, Atul Sahai, Yashpal S. Kanwar*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

212 Scopus citations

Abstract

Inhibitors of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase, also known as statins, are lipid-lowering agents widely used in the prevention of coronary heart disease. Recent experimental and clinical data, however, indicate that the overall benefits of statin therapy may exceed its cholesterol-lowering properties. We postulate that statins may ameliorate the detrimental effects of high glucose (HG)-induced proliferation of mesangial cells (MCs), a feature of early stages of diabetic nephropathy, by preventing Rho isoprenylation. Rat MCs cultured in HG milieu were treated with and without simvastatin, an HMG-CoA reductase inhibitor. Simvastatin inhibited HG-induced MC proliferation as measured by [3H]thymidine incorporation. This inhibitory effect was reversed with geranylgeranyl pyrophosphate, an isoprenoid intermediate of the cholesterol biosynthetic pathway. At the cell-cycle level, the HG-induced proliferation of MCs was associated with a decrease in cyclin dependent kinase (CDK) inhibitor p21 protein expression accompanied by an increase in CDK4 and CDK2 kinase activities. Simvastatin reversed the down-regulation of p21 protein expression and decreased CDK4 and CDK2 kinase activities. Exposure of MCs to HG was associated with an increase in membrane-associated Ras and Rho GTPase protein expression. Cotreatment of MCs with simvastatin reversed HG-induced Ras and Rho membrane translocation. Immunofluorescence microscopy revealed that the overexpression of the dominant-negative RhoA led to a significant increase in p21 expression. Our data suggest that simvastatin represses the HG-induced Rho GTPase/p21 signaling in glomerular MCs. Thus, this study provides a molecular basis for the use of statins, independently of their cholesterol-lowering effect, in early stages of diabetic nephropathy.

Original languageEnglish (US)
Pages (from-to)8301-8305
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume99
Issue number12
DOIs
StatePublished - Jun 11 2002

ASJC Scopus subject areas

  • General

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