Logo image
G-protein inactivator RGS6 mediates myocardial cell apoptosis and cardiomyopathy caused by doxorubicin
Journal article   Open access   Peer reviewed

G-protein inactivator RGS6 mediates myocardial cell apoptosis and cardiomyopathy caused by doxorubicin

Jianqi Yang, Biswanath Maity, Jie Huang, Zhan Gao, Adele Stewart, Robert M Weiss, Mark E Anderson and Rory A Fisher
Cancer research (Chicago, Ill.), Vol.73(6), pp.1662-1667
03/15/2013
DOI: 10.1158/0008-5472.CAN-12-3453
PMCID: PMC3602152
PMID: 23338613
url
https://doi.org/10.1158/0008-5472.CAN-12-3453View
Published (Version of record) Open Access

Abstract

Clinical use of the widely used chemotherapeutic agent doxorubicin is limited by life-threatening cardiotoxicity. The mechanisms underlying doxorubicin-induced cardiomyopathy and heart failure remain unclear but are thought to involve p53-mediated myocardial cell apoptosis. The tripartite G-protein inactivating protein RGS6 has been implicated in reactive oxygen species (ROS) generation, ATM/p53 activation, and apoptosis in doxorubicin-treated cells. Thus, we hypothesized that RGS6, the expression of which is enriched in cardiac tissue, might also be responsible for the pathologic effects of doxorubicin treatment in heart. In this study, we show that RGS6 expression is induced strongly by doxorubicin in the ventricles of mice and isolated ventricular myocytes via a posttranscriptional mechanism. While doxorubicin-treated wild-type (WT) mice manifested severe left ventricular dysfunction, loss of heart and body mass, along with decreased survival 5 days after doxorubicin administration, mice lacking RGS6 were completely protected against these pathogenic responses. Activation of ATM/p53 apoptosis signaling by doxorubicin in ventricles of WT mice was also absent in their RGS6(-/-) counterparts. Doxorubicin-induced ROS generation was dramatically impaired in both the ventricles and ventricular myocytes isolated from RGS6(-/-) mice, and the apoptotic response to doxorubicin in ventricular myocytes required RGS6-dependent ROS production. These results identify RGS6 as an essential mediator of the pathogenic responses to doxorubicin in heart, and they argue that RGS6 inhibition offers a rational means to circumvent doxorubicin cardiotoxicity in human patients with cancer.
RGS Proteins - genetics Reactive Oxygen Species - metabolism GTP-Binding Proteins - antagonists & inhibitors Humans Mice, Inbred C57BL Myocardium - pathology RGS Proteins - physiology Mice, Knockout Animals Antineoplastic Agents - pharmacology Mice Apoptosis - physiology Doxorubicin - pharmacology Cardiomyopathies - chemically induced

Details

Metrics

Logo image