Song Chun-Li, Liu Bin, Wang Jin-Peng, Zhang Bei-Lin, Zhang Ji-Chang, Zhao Li-Yan, Shi Yong-Feng, Li Yang-Xue, Wang Guan, Diao Hong-Ying, Li Qian, Xue Xin, Wu Jun-Duo, Liu Jia, Yu Yun-Peng, Cai Dan, Liu Zhi-Xian
Department of Cardiology, the Second Hospital of Jilin University, Changchun, 130041, P. R. China.
Department of Physiology, the College of Basic Medical Sciences of Jilin University, Changchun, 130021, P. R. China.
J Cell Biochem. 2015 Nov;116(11):2610-9. doi: 10.1002/jcb.25208.
This study aimed to investigate the effect of microRNA-30b (miR-30b) in rat myocardial ischemic-reperfusion (I/R) injury model. We randomly divided Sprague-Dawley (SD) rats (n = 80) into five groups: 1) control group; 2) miR-30b group; 3) sham-operated group; 4) I/R group, and 5) I/R+miR-30b group. Real-time quantitative polymerase chain reaction, immunohistochemical staining and Western blot analysis were conducted. TUNEL assay was employed for testing cardiomyocyte apoptosis. Our results showed that miR-30b levels were down-regulated in I/R group and I/R + miR-30b group compared with sham-operated group (both P < 0.05). However, miR-30b level in I/R + miR-30b group was higher than I/R group (P < 0.05). Markedly, the apoptotic rate in I/R group showed highest in I/R group (P < 0.05). Additionally, the results illustrated that protein levels of Bcl-2, Bax, and caspase-3 were at higher levels in ischemic regions in I/R group, comparing to sham-operated group (all P < 0.05), while Bcl-2/Bax was reduced (P < 0.05). Bcl-2 level and Bcl-2/Bax were obviously increased in I/R + miR-30b group by comparison with I/R group, and expression levels of Bax and caspase-3 were down-regulated (all P < 0.05). We also found that in I/R + miR-30b group, KRAS level was apparently lower and p-AKT level was higher by comparing with I/R group (both P < 0.05). Our study indicated that miR-30b overexpression had anti-apoptotic effect on early phase of rat myocardial ischemia injury model through targeting KRAS and activating the Ras/Akt pathway.
本研究旨在探讨微小RNA-30b（miR-30b）在大鼠心肌缺血再灌注（I/R）损伤模型中的作用。我们将80只Sprague-Dawley（SD）大鼠随机分为五组：1）对照组；2）miR-30b组；3）假手术组；4）I/R组，以及5）I/R+miR-30b组。进行了实时定量聚合酶链反应、免疫组织化学染色和蛋白质印迹分析。采用TUNEL法检测心肌细胞凋亡。我们的结果显示，与假手术组相比，I/R组和I/R+miR-30b组中miR-30b水平下调（均P<0.05）。然而，I/R+miR-30b组中的miR-30b水平高于I/R组（P<0.05）。明显地，I/R组中的凋亡率在I/R组中最高（P<0.05）。此外，结果表明，与假手术组相比，I/R组缺血区域中Bcl-2、Bax和caspase-3的蛋白质水平更高（均P<0.05），而Bcl-2/Bax降低（P<0.05）。与I/R组相比，I/R+miR-30b组中Bcl-2水平和Bcl-2/Bax明显升高，Bax和caspase-3的表达水平下调（均P<0.05）。我们还发现，与I/R组相比，I/R+miR-30b组中KRAS水平明显较低，p-AKT水平较高（均P<0.05）。我们的研究表明，miR-30b过表达通过靶向KRAS并激活Ras/Akt途径，对大鼠心肌缺血损伤模型的早期具有抗凋亡作用。
