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Oxidative Medicine and Cellular Longevity
Volume 2018, Article ID 4079041, 16 pages
https://doi.org/10.1155/2018/4079041
Research Article

Short-Duration Swimming Exercise after Myocardial Infarction Attenuates Cardiac Dysfunction and Regulates Mitochondrial Quality Control in Aged Mice

1Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi’an 710032, China
2Department of Geriatric, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi’an 710032, China
3Department of Aerospace Medicine, The Fourth Military Medical University, 169 Changle West Road, Xi’an 710032, China
4Department of Cardiology, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi’an 710032, China

Correspondence should be addressed to Wei Yi; nc.ude.ummf@iewiy and Feng Gao; nc.ude.ummf@oagf

Received 12 September 2017; Revised 21 December 2017; Accepted 24 January 2018; Published 11 April 2018

Academic Editor: Zsolt Radák

Copyright © 2018 Dajun Zhao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. Exercise benefits to cardiac rehabilitation (CR) following stable myocardial infarction (MI). The suitable exercise duration for aged patients with coronary heart disease (CHD) remains controversial, and the underlying molecular mechanism is still unclear. Methods and Results. 18-Month-old mice after stable MI were randomly submitted to different durations of exercise, including 15 and 60 min swimming training (ST) once per day, five times a week for 8 weeks. Compared to sedentary mice, 15 min ST, rather than 60 min ST, significantly augmented left ventricular function, increased survival rate, and suppressed myocardial fibrosis and apoptosis. 15 min ST improved mitochondrial morphology via regulating mitochondrial fission-fusion signaling. 15 min ST regulated mitophagy signaling via inhibiting LC3-II and P62 levels and increasing PINK/Parkin expression. 15 min ST also inhibited ROS production and enhanced antioxidant SOD2 activity. Notably, 15 min ST significantly increased sirtuin (SIRT) 3 level (2.7-fold) in vivo while the inhibition of SIRT3 exacerbated senescent H9c2 cellular LDH release and ROS production under hypoxia. In addition, SIRT3 silencing impairs mitochondrial dynamics and mitophagy in senescent cardiomyocytes against simulated ischemia (SI) injury. Conclusion. Collectively, our study demonstrated for the first time that sustained short-duration exercise, rather than long-duration exercise, attenuates cardiac dysfunction after MI in aged mice. It is likely that the positive regulation induced by a short-duration ST regimen on the elevated SIRT3 protein level improved mitochondrial quality control and decreased apoptosis and fibrosis contributed to the observed more resistant phenotype.