© 2004 by European Society of Cardiology
Copyright © 2004, European Society of Cardiology
Simvastatin reduces human atrial myofibroblast proliferation independently of cholesterol lowering via inhibition of RhoA
aInstitute for Cardiovascular Research, Worsley Building, University of Leeds, Leeds LS2 9JT, UK
bDepartment of Cardiac Surgery, The Yorkshire Heart Centre, Leeds General Infirmary, Leeds LS1 3EX, UK
* Corresponding author. Tel.: +44-113-3434807; fax: +44-113-3434803. medkep{at}leeds.ac.uk
Objective: Adverse atrial and ventricular myocardial remodeling is characterized by fibrosis, myocyte death or hypertrophy and fibroblast proliferation. HMG-CoA reductase inhibitors (statins) are widely prescribed cholesterol-lowering drugs that also appear to have beneficial effects on myocardial remodeling. Although statins are known to reduce myocyte hypertrophy, their effect on cardiac fibroblast proliferation is unknown. The purpose of this study was to investigate the effects of simvastatin on human atrial myofibroblast proliferation. Methods: Cardiac myofibroblasts were cultured from biopsies of human right atrial appendage. Proliferation was quantified by cell counting and cell cycle progression determined by immunoblotting for Cyclin A. The expression, activation and intracellular localization of RhoA were investigated using immunoblotting and immunocytochemistry. Results: Simvastatin (0.1–1.0 µmol/l) inhibited serum-induced myofibroblast proliferation in a concentration-dependent manner at a point upstream of Cyclin A expression. These effects were reversed by mevalonate or geranylgeranyl pyrophosphate (GGPP), but not squalene or farnesyl pyrophosphate (FPP), indicating a mechanism involving inhibition of Rho-family GTPases and independent of cholesterol synthesis. The effects of simvastatin were mimicked by inhibiting Rho geranylgeranylation or Rho-kinase activation. Furthermore, we demonstrated that simvastatin inhibited RhoA function by preventing its association with the plasma membrane and hence, its interaction with downstream effectors required for cell proliferation. Conclusions: Simvastatin reduced proliferation of cultured human atrial myofibroblasts independently of cholesterol synthesis via a mechanism involving inhibition of RhoA geranylgeranylation. Statins may therefore have an important role in preventing adverse myocardial remodeling associated with cardiac myofibroblast proliferation.
KEYWORDS Statins; Cardiac fibroblasts; Human; Cell proliferation; Remodeling; RhoA; Cyclin A
Time for primary review 23 days
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  T. Meyer-ter-Vehn, B. Katzenberger, H. Han, F. Grehn, and G. Schlunck Lovastatin Inhibits TGF-{beta}-Induced Myofibroblast Transdifferentiation in Human Tenon Fibroblasts Invest. Ophthalmol. Vis. Sci., September 1, 2008; 49(9): 3955 - 3960. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. L. Guy, D. W. Lambert, A. J. Turner, and K. E. Porter Functional angiotensin-converting enzyme 2 is expressed in human cardiac myofibroblasts Exp Physiol, May 1, 2008; 93(5): 579 - 588. [Abstract] [Full Text] [PDF]
|
|