Autophagic Adaptations to Long-term Habitual Exercise in Cardiac Muscle

Abstract

Autophagy has been shown to be responsive to physical exercise. However, the effects of prolonged habitual exercise on autophagy in cardiac muscle remain unknown. The present study aimed to examine whether long-term habitual exercise alters the basal autophagic signalling in cardiac muscle. Female Sprague-Dawley rats aged 2 months were randomly assigned to control and exercise groups. Animals in exercise group were kept in cages with free access exercise wheels to perform habitual exercise for 5 months. Animals in the control group were placed in cages without exercise wheels. Ventricular muscle tissues were harvested for analysis after 5 months. Phosphorylation statuses of upstream autophagic regulatory proteins and protein expressions of downstream autophagic facts remained unchanged in the cardiac muscle of exercise animals when compared to control animals. Intriguingly, the protein abundance of microtubule-associated protein-1 light chain -3 II (LC3-II), heat shock protein 72 (HSP72) and peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α) were significantly increased in cardiac muscle of exercise rats relative to control rats. 5 months of habitual exercise causes the adaptive increase in LC3-II reserve without altering autophagic flux, which probably contributes to the elevation of cellular autophagic capacity and efficiency of cardiac muscle.

Key words

autophagy - heart - LC3 - endurance exercise

• References

• 1 Adams V, Linke A, Wisloff U, Doring C, Erbs S, Krankel N, Witt CC, Labeit S, Muller-Werdan U, Schuler G, Hambrecht R. Myocardial expression of Murf-1 and MAFbx after induction of chronic heart failure: Effect on myocardial contractility. Cardiovasc Res 2007; 73: 120-129
• 2 Arad M, Seidman CE, Seidman JG. AMP-activated protein kinase in the heart: role during health and disease. Circ Res 2007; 100: 474-488
• 3 Bhuiyan MS, Pattison JS, Osinska H, James J, Gulick J, McLendon PM, Hill JA, Sadoshima J, Robbins J. Enhanced autophagy ameliorates cardiac proteinopathy. J Clin Invest 2013; 123: 5284-5297
• 4 Bjorkoy G, Lamark T, Pankiv S, Overvatn A, Brech A, Johansen T. Monitoring autophagic degradation of p62/SQSTM1. Methods Enzymol 2009; 452: 181-197
• 5 Bostrom P, Mann N, Wu J, Quintero PA, Plovie ER, Panakova D, Gupta RK, Xiao C, MacRae CA, Rosenzweig A, Spiegelman BM. C/EBPbeta controls exercise-induced cardiac growth and protects against pathological cardiac remodeling. Cell 2010; 143: 1072-1083
• 6 Cao DJ, Hill JA. Titrating autophagy in cardiac plasticity. Autophagy 2011; 7: 1078-1079
• 7 Chen CY, Hsu HC, Lee BC, Lin HJ, Chen YH, Huang HC, Ho YL, Chen MF. Exercise training improves cardiac function in infarcted rabbits: involvement of autophagic function and fatty acid utilization. Eur J Heart Fail 2010; 12: 323-330
• 8 Choi AM, Ryter SW, Levine B. Autophagy in human health and disease. N Engl J Med 2013; 368: 651-662
• 9 Chomczynski P, Sacchi N. The single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction: twenty-something years on. Nat Protoc 2006; 1: 581-585
• 10 Czubryt MP, McAnally J, Fishman GI, Olson EN. Regulation of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha) and mitochondrial function by MEF2 and HDAC5. Proc Natl Acad Sci USA 2003; 100: 1711-1716
• 11 Dutta D, Xu J, Kim JS, Dunn Jr WA, Leeuwenburgh C. Upregulated autophagy protects cardiomyocytes from oxidative stress-induced toxicity. Autophagy 2013; 9: 328-344
• 12 Eisele JC, Schaefer IM, Randel Nyengaard J, Post H, Liebetanz D, Bruel A, Muhlfeld C. Effect of voluntary exercise on number and volume of cardiomyocytes and their mitochondria in the mouse left ventricle. Basic Res Cardiol 2008; 103: 12-21
• 13 Friedrichsen M, Mortensen B, Pehmoller C, Birk JB, Wojtaszewski JF. Exercise-induced AMPK activity in skeletal muscle: role in glucose uptake and insulin sensitivity. Mol Cell Endocrinol 2013; 366: 204-214
• 14 Geng T, Li P, Okutsu M, Yin X, Kwek J, Zhang M, Yan Z. PGC-1alpha plays a functional role in exercise-induced mitochondrial biogenesis and angiogenesis but not fiber-type transformation in mouse skeletal muscle. Am J Physiol 2010; 298: C572-C579
• 15 Gutin B, Barbeau P, Owens S, Lemmon CR, Bauman M, Allison J, Kang HS, Litaker MS. Effects of exercise intensity on cardiovascular fitness, total body composition, and visceral adiposity of obese adolescents. Am J Clin Nutr 2002; 75: 818-826
• 16 Hamilton KL, Staib JL, Phillips T, Hess A, Lennon SL, Powers SK. Exercise, antioxidants, and HSP72: protection against myocardial ischemia/reperfusion. Free Radic Biol Med 2003; 34: 800-809
• 17 Hansen TE, Johansen T. Following autophagy step by step. BMC Biol 2011; 9: 39
• 18 Hariharan N, Maejima Y, Nakae J, Paik J, Depinho RA, Sadoshima J. Deacetylation of FoxO by Sirt1 plays an essential role in mediating starvation-induced autophagy in cardiac myocytes. Circ Res 2010; 107: 1470-1482
• 19 Harriss DJ, Atkinson G. Ethical standards in sport and exercise science research: 2014 update. Int J Sports Med 2013; 34: 1025-1028
• 20 Holloszy JO, Coyle EF. Adaptations of skeletal muscle to endurance exercise and their metabolic consequences. J Appl Physiol Respir Environ Exerc Physiol 1984; 56: 831-838
• 21 Ikeda S, Kawamoto H, Kasaoka K, Hitomi Y, Kizaki T, Sankai Y, Ohno H, Haga S, Takemasa T. Muscle type-specific response of PGC-1 alpha and oxidative enzymes during voluntary wheel running in mouse skeletal muscle. Acta Physiol (Oxf) 2006; 188: 217-223
• 22 Jakubowicz-Gil J, Langner E, Badziul D, Wertel I, Rzeski W. Silencing of Hsp27 and Hsp72 in glioma cells as a tool for programmed cell death induction upon temozolomide and quercetin treatment. Toxicol Appl Pharmacol 2013; 273: 580-589
• 23 Ji LL. Exercise-induced modulation of antioxidant defense. Ann N Y Acad Sci 2002; 959: 82-92
• 24 Kabeya Y, Mizushima N, Yamamoto A, Oshitani-Okamoto S, Ohsumi Y, Yoshimori T. LC3, GABARAP and GATE16 localize to autophagosomal membrane depending on form-II formation. J Cell Sci 2004; 117: 2805-2812
• 25 Kavazis AN, McClung JM, Hood DA, Powers SK. Exercise induces a cardiac mitochondrial phenotype that resists apoptotic stimuli. Am J Physiol 2008; 294: H928-H935
• 26 Kim J, Kundu M, Viollet B, Guan KL. AMPK and mTOR regulate autophagy through direct phosphorylation of Ulk1. Nat Cell Biol 2011; 13: 132-141
• 27 Klionsky DJ, Abdalla FC, Abeliovich H et al. Guidelines for the use and interpretation of assays for monitoring autophagy. Autophagy 2012; 8: 445-544
• 28 Kumarapeli AR, Horak KM, Glasford JW, Li J, Chen Q, Liu J, Zheng H, Wang X. A novel transgenic mouse model reveals deregulation of the ubiquitin-proteasome system in the heart by doxorubicin. FASEB J 2005; 19: 2051-2053
• 29 Lehman JJ, Barger PM, Kovacs A, Saffitz JE, Medeiros DM, Kelly DP. Peroxisome proliferator-activated receptor gamma coactivator-1 promotes cardiac mitochondrial biogenesis. J Clin Invest 2000; 106: 847-856
• 30 Li S, Zhou Y, Fan J, Cao S, Cao T, Huang F, Zhuang S, Wang Y, Yu X, Mao H. Heat shock protein 72 enhances autophagy as a protective mechanism in lipopolysaccharide-induced peritonitis in rats. Am J Pathol 2011; 179: 2822-2834
• 31 Lira VA, Okutsu M, Zhang M, Greene NP, Laker RC, Breen DS, Hoehn KL, Yan Z. Autophagy is required for exercise training-induced skeletal muscle adaptation and improvement of physical performance. FASEB J 2013; 27: 4184-4193
• 32 Nakai A, Yamaguchi O, Takeda T, Higuchi Y, Hikoso S, Taniike M, Omiya S, Mizote I, Matsumura Y, Asahi M, Nishida K, Hori M, Mizushima N, Otsu K. The role of autophagy in cardiomyocytes in the basal state and in response to hemodynamic stress. Nat Med 2007; 13: 619-624
• 33 Ogura Y, Iemitsu M, Naito H, Kakigi R, Kakehashi C, Maeda S, Akema T. Single bout of running exercise changes LC3-II expression in rat cardiac muscle. Biochem Biophys Res Commun 2011; 414: 756-760
• 34 Olesen J, Kiilerich K, Pilegaard H. PGC-1alpha-mediated adaptations in skeletal muscle. Pflugers Arch 2010; 460: 153-162
• 35 Renna M, Schaffner C, Winslow AR, Menzies FM, Peden AA, Floto RA, Rubinsztein DC. Autophagic substrate clearance requires activity of the syntaxin-5 SNARE complex. J Cell Sci 2011; 124: 469-482
• 36 Sambandam N, Lopaschuk GD, Brownsey RW, Allard MF. Energy metabolism in the hypertrophied heart. Heart Fail Rev 2002; 7: 161-173
• 37 Sengupta A, Molkentin JD, Yutzey KE. FoxO transcription factors promote autophagy in cardiomyocytes. J Biol Chem 2009; 284: 28319-28331
• 38 Shehata M, Matsumura H, Okubo-Suzuki R, Ohkawa N, Inokuchi K. Neuronal stimulation induces autophagy in hippocampal neurons that is involved in AMPA receptor degradation after chemical long-term depression. J Neurosci 2012; 32: 10413-10422
• 39 Siu PM, Pei XM, Teng BT, Benzie IF, Ying M, Wong SH. Habitual exercise increases resistance of lymphocytes to oxidant-induced DNA damage by upregulating expression of antioxidant and DNA repairing enzymes. Exp Physiol 2011; 96: 889-906
• 40 Spangenberg EM, Augustsson H, Dahlborn K, Essen-Gustavsson B, Cvek K. Housing-related activity in rats: effects on body weight, urinary corticosterone levels, muscle properties and performance. Lab Anim 2005; 39: 45-57
• 41 Tanaka Y, Guhde G, Suter A, Eskelinen EL, Hartmann D, Lullmann-Rauch R, Janssen PM, Blanz J, von Figura K, Saftig P. Accumulation of autophagic vacuoles and cardiomyopathy in LAMP-2-deficient mice. Nature 2000; 406: 902-906
• 42 Wang J. Beclin 1 bridges autophagy, apoptosis and differentiation. Autophagy 2008; 4: 947-948
• 43 Wang J, Whiteman MW, Lian H, Wang G, Singh A, Huang D, Denmark T. A non-canonical MEK/ERK signaling pathway regulates autophagy via regulating Beclin 1. J Biol Chem 2009; 284: 21412-21424
• 44 Wohlgemuth SE, Julian D, Akin DE, Fried J, Toscano K, Leeuwenburgh C, Dunn Jr WA. Autophagy in the heart and liver during normal aging and calorie restriction. Rejuven Res 2007; 10: 281-292
• 45 Wright DC, Han DH, Garcia-Roves PM, Geiger PC, Jones TE, Holloszy JO. Exercise-induced mitochondrial biogenesis begins before the increase in muscle PGC-1alpha expression. J Biol Chem 2007; 282: 194-199
• 46 Xie M, Morales CR, Lavandero S, Hill JA. Tuning flux: autophagy as a target of heart disease therapy. Curr Opin Cardiol 2011; 26: 216-222
• 47 Xu X, Kobayashi S, Chen K, Timm D, Volden P, Huang Y, Gulick J, Yue Z, Robbins J, Epstein PN, Liang Q. Diminished autophagy limits cardiac injury in mouse models of type 1 diabetes. J Biol Chem 2013; 288: 18077-18092
• 48 Yamamoto T, Ohkuwa T, Itoh H, Sato Y, Naoi M. Effect of gender differences and voluntary exercise on antioxidant capacity in rats. Comp Biochem Physiol C Toxicol Pharmacol 2002; 132: 437-444
• 49 Zhang L, Sheng R, Qin Z. The lysosome and neurodegenerative diseases. Acta Biochim Biophys Sin (Shanghai) 2009; 41: 437-445
• 50 Zhang XD, Qi L, Wu JC, Qin ZH. DRAM1 regulates autophagy flux through lysosomes. PLoS One 2013; 8: e63245
• 51 Zhao J, Brault JJ, Schild A, Goldberg AL. Coordinate activation of autophagy and the proteasome pathway by FoxO transcription factor. Autophagy 2008; 4: 378-380