Voluntary exercise training attenuated the middle-aged maturity-induced cardiac apoptosis

Interaction of exercise training with taurine attenuates infarct size and cardiac dysfunction via Akt-Foxo3a-Caspase-8 signaling pathway

This research aimed to investigate the synergistic protective effect of exercise training and taurine on Akt-Foxo3a-Caspase-8 signaling related to infarct size and cardiac dysfunction. Therefore, 25 male Wistar rats with MI were divided into five groups: sham (Sh), control-MI(C-MI), exercise training-MI(Exe-MI), taurine supplementation-MI(Supp-MI), and exercise training + taurine-MI(Exe + Supp-MI). The taurine groups were given a 200 mg/kg/day dose of taurine by drinking water. Exercise training was conducted for 8 weeks (5 days/week), each session alternated 2 min with 25-30% VO2peak and 4 min with 55-60% VO2peak for 10 alternations. Then, the left ventricle tissue samples were taken from all groups. Exercise training and taurine activated Akt and decreased Foxo3a. Expression of the caspase-8 gene was increased in cardiac necrosis after MI, While, after 12 weeks of intervention decreased. Results exhibited that exercise training combined with taurine has a greater effect than either alone on activating the Akt-Foxo3a-caspase signaling pathway (P < 0.001). MI-induced myocardial injury leads to increase collagen deposition (P < 0.001) and infarct size and results in cardiac dysfunction via reduced stroke volume, ejection fraction, and fractional shortening (P < 0.001). Exercise training and taurine improved cardiac functional parameters (SV, EF, FS) and infarct size (P < 0.001) after 8 weeks of intervention in rats with MI. Also, the interaction of exercise training and taurine has a greater effect than alone on these variables. Interaction of exercise training with taurine supplementation induces a general amelioration of the cardiac histopathological profiles and improves cardiac remodeling via activating Akt-Foxo3a-Caspase-8 signaling with protective effects against MI.

Mechanisms of Exercise-Induced Cardiac Remodeling Differ Between Young and Aged Hearts

Aging induces physiological and molecular changes in the heart that increase the risk for heart disease. Several of these changes are targetable by exercise. We hypothesize that the mechanisms by which exercise improves cardiac function in the aged heart differ from those in the young exercised heart.

Exercise-Induced Cardiac Troponin Elevations: From Underlying Mechanisms to Clinical Relevance

Supplemental Digital Content is available in the text.

Serological assessment of cardiac troponins (cTn) is the gold standard to assess myocardial injury in clinical practice. A greater magnitude of acutely or chronically elevated cTn concentrations is associated with lower event-free survival in patients and the general population. Exercise training is known to improve cardiovascular function and promote longevity, but exercise can produce an acute rise in cTn concentrations, which may exceed the upper reference limit in a substantial number of individuals. Whether exercise-induced cTn elevations are attributable to a physiological or pathological response and if they are clinically relevant has been debated for decades. Thus far, exercise-induced cTn elevations have been viewed as the only benign form of cTn elevations. However, recent studies report intriguing findings that shed new light on the underlying mechanisms and clinical relevance of exercise-induced cTn elevations. We will review the biochemical characteristics of cTn assays, key factors determining the magnitude of postexercise cTn concentrations, the release kinetics, underlying mechanisms causing and contributing to exercise-induced cTn release, and the clinical relevance of exercise-induced cTn elevations. We will also explain the association with cardiac function, correlates with (subclinical) cardiovascular diseases and exercise-induced cTn elevations predictive value for future cardiovascular events. Last, we will provide recommendations for interpretation of these findings and provide direction for future research in this field.

Effect of different exercise training intensities on age-related cardiac damage in male mice

Aging is the most important risk factor for cardiovascular diseases. Although exercise is known to be beneficial for the health of aging heart, the optimal exercise training intensity to prevent natural aging-induced cardiac damage has not been defined. In this study, we used 32-week-old male mice and randomly divided them into three groups, namely, untrained (UNT) mice, moderate-intensity exercise training (MET) mice, and high-intensity interval training (HIIT) mice. Mice in the two exercise training groups were subjected to exercise 5 days per week for 24 consecutive weeks. Metabolic characteristics, cardiac function and morphology, myocardial remodeling, myocardial fibrosis (collagen III, α-SMA, and TGF-β), oxidative stress (NRF2, HO-1, SOD, and NOX4), and apoptosis (BAX, Bak, Bcl-2, and Bcl-XL) were analyzed 24 weeks after the different treatments. MET improved cardiac function and reduced myocardial remodeling, myocardial fibrosis, and oxidative stress in the aging heart. MET treatment exerted an anti-apoptotic effect in the heart of the aging mice. Importantly, HIIT did not protect against cardiac damage during the natural aging process. These findings suggest that MET may be one of the main methods to prevent cardiac damage induced by natural aging.