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

Abstract

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.

Keywords: Akt; Caspase-8; Exercise Training; Foxo3a; Myocardial Infarct Size; Taurine.