Suzuki K, Sawa Y, Kagisaki K, Taketani S, Ichikawa H, Kaneda Y, Matsuda H
First Department of Surgery, Osaka University Medical School, Suita, Japan.
Basic Res Cardiol. 2000 Oct;95(5):397-403. doi: 10.1007/s003950070039.
It is reported that ischemia-reperfusion induces apoptotic cell death in myocardium. It is also demonstrated that heat shock protein 70 (HSP70) enhances myocardial tolerance. Therefore, it is hypothesized that HSP70 may play a role in the attenuation of myocardial apoptosis. To elucidate this goal, HSP70-overexpressing and control-transfected rat hearts were prepared using gene transfection by intra-coronary infusion of the hemagglutinating virus of Japan-liposome. In vivo experiment Hearts of both groups were subjected to global ischemia, followed by reperfusion in situ. Shorter recovery time to spontaneous beating (HSP70-transfected vs. control-transfected; 46.7+/-4.6 vs. 67.5+/-7.0 s, p = 0.033) and lower serum CPK levels (415+/-27 vs. 533+/-36 IU, p = 0.027) were observed in the HSP70-transfected group. The HSP70-transfected group also showed a lower percentage of cardiac myocytes positively stained by nick end labeling after ischemia-reperfusion (17.5+/-4.9 vs. 40.0+/-5.1%, p = 0.010). In vitro experiment Cardiac myocytes isolated from the hearts of both groups (prepared separately from the in vivo experiment) were subjected to hypoxia-reoxygenation. Flow cytometry was used to identify the cells that showed sub-G1 DNA content as apoptotic cells. Apoptotic cells as a percentage of viable cells increased more in the control-transfected group after hypoxia-reoxygenation (13.0+/-0.77 vs. 21.9+/-1.18%, p<0.0001). In conclusion, we demonstrated that apoptosis after ischemia-reperfusion was decreased in the HSP70-overexpressing heart in vivo and in vitro, leading to the suggestion that HSP70 could be associated with the reduction in myocardial apoptosis.
据报道，缺血再灌注可诱导心肌细胞发生凋亡性死亡。也有研究表明，热休克蛋白70（HSP70）可增强心肌耐受性。因此，推测HSP70可能在减轻心肌细胞凋亡中发挥作用。为阐明这一目的，通过冠状动脉内注入日本血凝病毒-脂质体进行基因转染，制备了HSP70过表达和对照转染的大鼠心脏。体内实验 两组大鼠心脏均进行全心缺血，然后原位再灌注。HSP70转染组自发搏动恢复时间较短（HSP70转染组与对照转染组；46.7±4.6秒对67.5±7.0秒，p = 0.033），血清CPK水平较低（415±27对533±36 IU，p = 0.027）。HSP70转染组在缺血再灌注后心肌细胞经缺口末端标记法阳性染色的百分比也较低（17.5±4.9对40.0±5.1%，p = 0.010）。体外实验 从两组大鼠心脏（与体内实验分别制备）分离的心肌细胞进行缺氧复氧处理。采用流式细胞术鉴定显示亚G1期DNA含量的细胞为凋亡细胞。缺氧复氧后，对照转染组凋亡细胞占活细胞的百分比增加更多（13.0±0.77对21.9±1.18%，p<0.0001）。总之，我们证明，体内和体外实验中，HSP70过表达的心脏缺血再灌注后的细胞凋亡减少，这表明HSP70可能与心肌细胞凋亡的减少有关。
