Association of the PPARγ/PI3K/Akt pathway with the cardioprotective effects of tacrolimus in myocardial ischemic/reperfusion injury

Abstract

Myocardial ischemia/reperfusion injury (MIRI) induces severe arrhythmias and has a high risk of mortality. The aim of the present study was to investigate the effect of tacrolimus on arrhythmias, cardiac function, oxidative stress and myocardium apoptosis induced by MIRI, and to elucidate the underlying mechanism. The effects of MIRI and tacrolimus on arrhythmias, cardiac function parameters, myocardial oxidative stress and apoptosis were investigated in a rat model of MIRI. The phosphorylation of peroxisome proliferator-Activated receptor γ (PPARγ) and protein kinase B (Akt) was investigated via western blotting. After rats were treated with inhibitors of PPARγ/phosphoinositide 3-kinase (PI3K)/Akt, cardiac function parameters were measured. The results demonstrated that the MIRI procedure induced arrhythmias and significant impairment of cardiac function, oxidative stress and apoptosis in cardiomyocytes (P<0.05). Tacrolimus significantly alleviated the arrhythmias and impairment of cardiac function and inhibited the oxidative stress and apoptosis in cardiomyocytes (P<0.05). The phosphorylation of PPARγ and Akt was significantly activated by tacrolimus, whereas inhibitors of PPARγ/PI3K/Akt significantly abolished the effects of tacrolimus (P<0.05). Together, these results suggest that tacrolimus may protect rats from MIRI through activation of the PPARγ/PI3K/Akt pathway.