BACKGROUND: Dilated cardiomyopathy (DCM), characterized by dilatation and dysfunction of the left ventricle, is an important cause of heart failure. Many mutations in various genes, including cytoskeletal protein genes and contractile protein genes, have been identified in DCM patients, but the mechanisms of how such mutations lead to DCM remain unknown. METHODS AND RESULTS: We established the mouse model of DCM by expressing a mutated cardiac alpha-actin gene, which has been reported in patients with DCM, in the heart (mActin-Tg). mActin-Tg mice showed gradual dilatation and dysfunction of the left ventricle, resulting in death by heart failure. The number of apoptotic cardiomyocytes and protein levels of p53 were increased in the hearts of mActin-Tg mice. Overexpression of Bcl-2 or downregulation of p53 decreased the number of apoptotic cardiomyocytes and improved cardiac function. This mouse model showed a decrease in myofilament calcium sensitivity and activation of calcium/calmodulin-dependent kinase IIdelta (CaMKIIdelta). The inhibition of CaMKIIdelta prevented the increase in p53 and apoptotic cardiomyocytes and ameliorated cardiac function. CONCLUSIONS: CaMKIIdelta plays a critical role in the development of heart failure in part by accumulation of p53 and induction of cardiomyocyte apoptosis in the DCM mouse model.
BACKGROUND:Dilated cardiomyopathy (DCM), characterized by dilatation and dysfunction of the left ventricle, is an important cause of heart failure. Many mutations in various genes, including cytoskeletal protein genes and contractile protein genes, have been identified in DCMpatients, but the mechanisms of how such mutations lead to DCM remain unknown. METHODS AND RESULTS: We established the mouse model of DCM by expressing a mutated cardiac alpha-actin gene, which has been reported in patients with DCM, in the heart (mActin-Tg). mActin-Tgmice showed gradual dilatation and dysfunction of the left ventricle, resulting in death by heart failure. The number of apoptotic cardiomyocytes and protein levels of p53 were increased in the hearts of mActin-Tgmice. Overexpression of Bcl-2 or downregulation of p53 decreased the number of apoptotic cardiomyocytes and improved cardiac function. This mouse model showed a decrease in myofilament calcium sensitivity and activation of calcium/calmodulin-dependent kinase IIdelta (CaMKIIdelta). The inhibition of CaMKIIdelta prevented the increase in p53 and apoptotic cardiomyocytes and ameliorated cardiac function. CONCLUSIONS: CaMKIIdelta plays a critical role in the development of heart failure in part by accumulation of p53 and induction of cardiomyocyte apoptosis in the DCMmouse model.
Authors: Barry J Maron; Jeffrey A Towbin; Gaetano Thiene; Charles Antzelevitch; Domenico Corrado; Donna Arnett; Arthur J Moss; Christine E Seidman; James B Young Journal: Circulation Date: 2006-03-27 Impact factor: 29.690
Authors: Haiyun Ling; Tong Zhang; Laetitia Pereira; Christopher Kable Means; Hongqiang Cheng; Yusu Gu; Nancy D Dalton; Kirk L Peterson; Ju Chen; Donald Bers; Joan Heller Brown; Joan Heller Brown Journal: J Clin Invest Date: 2009-04-20 Impact factor: 14.808
Authors: Wei Guo; Sebastian Schafer; Marion L Greaser; Michael H Radke; Martin Liss; Thirupugal Govindarajan; Henrike Maatz; Herbert Schulz; Shijun Li; Amanda M Parrish; Vita Dauksaite; Padmanabhan Vakeel; Sabine Klaassen; Brenda Gerull; Ludwig Thierfelder; Vera Regitz-Zagrosek; Timothy A Hacker; Kurt W Saupe; G William Dec; Patrick T Ellinor; Calum A MacRae; Bastian Spallek; Robert Fischer; Andreas Perrot; Cemil Özcelik; Kathrin Saar; Norbert Hubner; Michael Gotthardt Journal: Nat Med Date: 2012-05 Impact factor: 53.440