Aerobic exercise modulates mitochondrial quality control system to reverse cardiac pathological remodeling in aging rats
- VernacularTitle:有氧运动调控线粒体质量控制系统逆转衰老大鼠心脏的病理性重塑
- Author:
Liang TANG
1
;
Hexia WANG
;
Qingbo WANG
;
Yihua PI
;
Yan ZHANG
Author Information
- Keywords: aerobic exercise; aging; cardiac remodeling; mitochondrial quality control; biogenesis; fusion and fission; mitophagy
- From: Chinese Journal of Tissue Engineering Research 2024;28(16):2534-2541
- CountryChina
- Language:Chinese
- Abstract: BACKGROUND:Aging is associated with increased susceptibility to cardiovascular disease,and mitochondrial dysfunction plays a key role in the pathogenesis of cardiovascular disease.Regular physical activity is beneficial to cardiovascular health and can prevent and treat chronic heart disease.However,the specific mechanism of mitochondria in the protective effect of exercise on the aging heart has not yet been clarified. OBJECTIVE:To explore the effect of aerobic exercise on cardiac pathological remodeling in aging rats and to investigate the possible mechanism of mitochondrial quality control system. METHODS:Sixty Wistar rats were randomly divided into young sedentary group(6 months old),old sedentary group(20 months old)and old exercise group(20 months old)with 20 rats in each group.Rats in the young sedentary and old sedentary groups were fed in cages for 12 weeks,while those in the old exercise group underwent moderate-intensity aerobic treadmill exercise(60%of the maximal running speed,slope 0°,60 minute per day,5 days per week)for 12 weeks.After the experiment,the heart was extracted for relevant indicator tests. RESULTS AND CONCLUSION:Cardiac morphology and myocardial histopathology:compared with the young sedentary group,the rats in the old sedentary group presented with concentric cardiac hypertrophy,myocardial fibrosis,myocardial cell apoptosis and loss,and cardiac diastolic dysfunction(P＜0.05);compared with the old sedentary group,animals in the old exercise group showed reduced myocardial fibrosis and apoptosis rates,increased cell numbers,improved cardiac function(P＜0.05),and a transition in cardiac phenotype from pathological to physiological hypertrophy.Mitochondrial function:compared with the young sedentary group,the generation rate of mitochondrial hydrogen peroxide increased(P＜0.05),respiration rate and respiratory control ratio of state 3 and state 4 decreased(P＜0.05),activities of respiratory chain complexes Ⅰ,Ⅱ and Ⅳ decreased(P＜0.05),mitochondrial calcium retention capacity decreased(P＜0.05),and mitochondrial permeability transition pore opening increased(P＜0.05)in the old sedentary group.Compared with the old sedentary group,all of the above indicators were significantly improved in the old exercise group(P＜0.05).Mitochondrial quality control:compared with the young sedentary group,mitochondrial biogenesis decreased(P＜0.05),mitophagy activity increased(P＜0.05),mitochondrial fusion reduced(P＜0.05),and fission raised(P＜0.05)in the old sedentary group;compared with the old sedentary group,mitochondrial biogenesis and mitophagy activity increased(P＜0.05),mitochondrial fusion raised(P＜0.05)and fission decreased(P＜0.05)in the old exercise group.To conclude,regular aerobic exercises exert cardioprotective effects in aging rats by regulating the mitochondrial quality control system,thus reversing pathological cardiac remodeling and improving cardiac function.
