H₂O₂ Signaling-Triggered PI3K Mediates Mitochondrial Protection to Participate in Early Cardioprotection by Exercise Preconditioning

Figure 4

Regulation of mitochondrial protection during EEP-induced cardioprotection. (a) Changes in the ratio of phosphorylated VDAC1 (p-VDAC1) to nonphosphorylated VDAC1 (0-VDAC1), as indicated by Phos-tag blotting. Comparison of groups EE and EEP + EE to C and that of group W + EEP + EE to EE and EEP + EE showed significant differences (). (b) Changes in p-Akt expression. Comparison of groups EE, W + EEP, and W + EEP + EE to C showed significant differences (). Comparison of group EEP + EE to EE and W + EEP + EE showed significant differences (). (c) Changes in the expression of cytosolic Cyt-c by immunoblotting. Comparison of group W + EEP + EE to EE showed a significant difference (). (d) Mitochondrial Cyt-c. Comparison of group W + EEP + EE to C, EE, and EEP showed significant differences (). (e) Changes in the ratio of cytosolic Cyt-c to mitochondrial Cyt-c. Comparison of group W + EEP + EE to EE showed a significant difference (). (f) Changes in mitochondrial Drp-1 expression. Comparison of group W + EEP to C and that of group W + EEP + EE to C, EE, and EEP + EE showed significant differences (). (g) Changes in Beclin1 expression. Comparison of group EEP + EE to C and that of group W + EEP + EE to C, EE, and W + EEP showed significant differences (). (h) Bcl-2 expression did not differ among groups. (i) Changes in the ratio of Beclin1 to Bcl-2. Comparison of group W + EEP + EE to C showed a significant difference (). (j) Changes in total (T) SOD activity. Comparison of groups EE, EEP, and W + EEP to C, group EEP + EE to EE and EEP, and group W + EEP + EE to EE showed significant differences (). (k) Changes in MnSOD activity. Comparison of groups EEP and W + EEP to C, group EEP + EE to EEP, and group W + EEP + EE to C and EE showed significant differences (). (l) Measurement of MnSOD expression levels by immunoblotting showed no differences among groups. Compared to C; ^§compared to EE; ^†compared to EEP; ^&compared to EEP + EE; compared to W + EEP. C: control; EE: exhaustive exercise; EEP: early exercise preconditioning; EEP + EE: early exercise preconditioning plus exhaustive exercise; W + EEP: wortmannin plus early exercise preconditioning; W + EEP + EE: wortmannin plus early exercise preconditioning plus exhaustive exercise.