Figure 4.

HIF-1α activation mediates Ube2s role in cardiomyocyte apoptosis and MI/R injury. (A–C) C57BL/6 mice were intra-myocardially infected with lentivirus expressing vector control or Ube2s in the presence or absence of transfection of control siRNA (siCtrl) or HIF-1α siRNA (siHIF-1α) 48 h prior to MI/R surgery. Following 24 h of reperfusion, the protein level of Ube2s, HIF-1α, Bax and Bcl-2 in the heart was analyzed by Western blotting. Samples from sham group were used as controls. Each group includes 8 mice. β-Actin was used as a loading control. The representative band images (A) and relative band intensity analysis of HIF-1α and ratio of Bax/Bcl-2 (B) are presented. (C) The supernatants of the homogenized heart samples were collected, and the caspase-3 activity was determined. The results are expressed as the nmol AFC/h/mg protein. Data are mean ± SD. Data were compared using Student’s t-test. **, P < 0.01; NS, not significant. (D) Heart samples were harvested as described in (A), and the mid-myocardial cross sections were prepared. The infarct size in the heart sections was quantified, and the results of percentage of size are shown. AAR/LVA, ratio of area at risk (AAR) to left ventricular area (LVA); IA/AAR, ratio of infarct area (IA) to AAR. Data are mean ± SD. Data were compared using Student’s t-test. **, P < 0.01; *, P < 0.05; NS, not significant. (E) C57BL/6 mice were treated as in (A). The samples of serum were collected and the level of creatine phosphokinase (CPK) was quantified. Data are mean ± SD. Data were compared using Student’s t-test. **, P < 0.01.