The modulation of sirtuins and apoptotic proteins in rats after exhaustive exercise

A large body of evidence shows that a single bout of strenuous exercise induces oxidative stress in circu- lating human lymphocytes leading to lipid peroxide- tion, DNA damage, mitochondrial perturbations, and protein oxidation. In a training experiment, Wistar rats were divided into control group (CG) and exer- cise group (EG). After a running level exercise until exhaustion, we observed an increase in the mRNA content and protein expression of SIRT1 and SIRT7 in the EG compared to the CG. Moreover, such train- ing exercise did not change mRNA transcripts and protein expression of FOXO3A and GADD45. We also observed an increase of pro-apoptotic protein bax and a decrease of the anti-apoptotic protein bcl-2 in the EG. Accordingly, we observed a caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage only in EG rats. Statistical analysis of the data showed a significant correlation between SIRT1 and SIRT7 expression and apoptotic proteins such as bax, bcl-2 in both tissues. We conclude that, in both muscle, such exercise activates both a damaging apoptotic mecha- nism with bax increase and bcl-2 decrease and a counterbalancing protective mechanism with SIRT1 and SIRT7 increase.