Jing Yan1,2,3, Jian-Yun Yan1,2,3, Yu-Xi Wang1,2,3, Yuan-Na Ling1,2,3, Xu-Dong Song1,2,3, Si-Yi Wang1,2,3, Hai-Qiong Liu1,2,3, Qi-Cai Liu1,2,3, Ya Zhang4, Ping-Zhen Yang1,2,3, Xian-Bao Wang1,2,3, Ai-Hua Chen1,2,3. 1. Laboratory of Heart Center and Department of Cardiology, Heart Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China. 2. Laboratory of Heart Center, Guangdong Provincial Biomedical Engineering Technology Research Center for Cardiovascular Disease, Guangzhou, China. 3. Laboratory of Heart Center, Sino-Japanese Cooperation Platform for Translational Research in Heart Failure, Guangzhou, China. 4. Department of Cardiology, Xiangdong Affiliated Hospital of Hunan Normal University, Zhuzhou, Hunan, China.
Abstract
BACKGROUND AND PURPOSE: Spermidine, a natural polyamine, is abundant in mammalian cells and is involved in cell growth, proliferation, and regeneration. Recently, oral spermidine supplements were cardioprotective in age-related cardiac dysfunction, through enhancing autophagic flux. However, the effect of spermidine on myocardial injury and cardiac dysfunction following myocardial infarction (MI) remains unknown. EXPERIMENTAL APPROACH: We determined the effects of spermidine in a model of MI, Sprague-Dawley rats with permanent ligation of the left anterior descending artery, and in cultured neonatal rat cardiomyocytes (NRCs) exposed to angiotensin II (Ang II). Cardiac function in vivo was assessed with echocardiography. In vivo and in vitro studies used histological and immunohistochemical techniques, along with western blots. KEY RESULTS: Spermidine improved cardiomyocyte viability and decreased cell necrosis in NRCs treated with angiotensin II. In rats post-MI, spermidine reduced infarct size, improved cardiac function, and attenuated myocardial hypertrophy. Spermidine also suppressed the oxidative damage and inflammatory cytokines induced by MI. Moreover, spermidine enhanced autophagic flux and decreased apoptosis both in vitro and in vivo. The protective effects of spermidine on cardiomyocyte apoptosis and cardiac dysfunction were abolished by the autophagy inhibitor chloroquine, indicating that spermidine exerted cardioprotective effects at least partly through promoting autophagic flux, by activating the AMPK/mTOR signalling pathway. CONCLUSIONS AND IMPLICATIONS: Our findings suggest that spermidine improved MI-induced cardiac dysfunction by promoting AMPK/mTOR-mediated autophagic flux.
BACKGROUND AND PURPOSE:Spermidine, a natural polyamine, is abundant in mammalian cells and is involved in cell growth, proliferation, and regeneration. Recently, oral spermidine supplements were cardioprotective in age-related cardiac dysfunction, through enhancing autophagic flux. However, the effect of spermidine on myocardial injury and cardiac dysfunction following myocardial infarction (MI) remains unknown. EXPERIMENTAL APPROACH: We determined the effects of spermidine in a model of MI, Sprague-Dawley rats with permanent ligation of the left anterior descending artery, and in cultured neonatal rat cardiomyocytes (NRCs) exposed to angiotensin II (Ang II). Cardiac function in vivo was assessed with echocardiography. In vivo and in vitro studies used histological and immunohistochemical techniques, along with western blots. KEY RESULTS:Spermidine improved cardiomyocyte viability and decreased cell necrosis in NRCs treated with angiotensin II. In rats post-MI, spermidine reduced infarct size, improved cardiac function, and attenuated myocardial hypertrophy. Spermidine also suppressed the oxidative damage and inflammatory cytokines induced by MI. Moreover, spermidine enhanced autophagic flux and decreased apoptosis both in vitro and in vivo. The protective effects of spermidine on cardiomyocyte apoptosis and cardiac dysfunction were abolished by the autophagy inhibitor chloroquine, indicating that spermidine exerted cardioprotective effects at least partly through promoting autophagic flux, by activating the AMPK/mTOR signalling pathway. CONCLUSIONS AND IMPLICATIONS: Our findings suggest that spermidine improved MI-induced cardiac dysfunction by promoting AMPK/mTOR-mediated autophagic flux.
Authors: Paul Tannous; Hongxin Zhu; Andriy Nemchenko; Jeff M Berry; Janet L Johnstone; John M Shelton; Francis J Miller; Beverly A Rothermel; Joseph A Hill Journal: Circulation Date: 2008-06-09 Impact factor: 29.690
Authors: Christine Zoumas-Morse; Cheryl L Rock; Elizabeth L Quintana; Marian L Neuhouser; Eugene W Gerner; Frank L Meyskens Journal: J Am Diet Assoc Date: 2007-06