HEALTH NEWS

Study Title:

Statins Can Turn on a Gene Signal that Damages Muscles

Study Abstract

Statins inhibit HMG-CoA reductase, a key enzyme in cholesterol synthesis, and are widely used to treat hypercholesterolemia. These drugs can lead to a number of side effects in muscle, including muscle fiber breakdown; however, the mechanisms of muscle injury by statins are poorly understood. We report that lovastatin induced the expression of atrogin-1, a key gene involved in skeletal muscle atrophy, in humans with statin myopathy, in zebrafish embryos, and in vitro in murine skeletal muscle cells. In cultured mouse myotubes, atrogin-1 induction following lovastatin treatment was accompanied by distinct morphological changes, largely absent in atrogin-1 null cells. In zebrafish embryos, lovastatin promoted muscle fiber damage, an effect that was closely mimicked by knockdown of zebrafish HMG-CoA reductase. Moreover, atrogin-1 knockdown in zebrafish embryos prevented lovastatin-induced muscle injury. Finally, overexpression of PGC-1α, a transcriptional coactivator that induces mitochondrial biogenesis and protects against the development of muscle atrophy, dramatically prevented lovastatin-induced muscle damage and abrogated atrogin-1 induction both in fish and in cultured mouse myotubes. Collectively, our human, animal, and in vitro findings shed light on the molecular mechanism of statin-induced myopathy and suggest that atrogin-1 may be a critical mediator of the muscle damage induced by statins.

Study Information

Jun-ichi Hanai, Peirang Cao, Preeti Tanksale, Shintaro Imamura, Eriko Koshimizu, Jinghui Zhao, Shuji Kishi, Michiaki Yamashita, Paul S. Phillips, Vikas P. Sukhatme and Stewart H. Lecker.
The muscle-specific ubiquitin ligase atrogin-1/MAFbx mediates statin-induced muscle toxicity.
J. Clin. Invest.
2007 December
1Renal Division and Division of Interdisciplinary Medicine and Biotechnology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.

Full Study

http://www.jci.org/articles/view/32741/version/3