骨髓间充质干细胞预移植1周后构建心肌缺血再灌注损伤大鼠模型

Construction of rat models of myocardial ischemia/reperfusion injury following bone marrow mesenchymal stem cell pretransplantation for 1 week

背景:急性心肌梗死用溶栓或介入手段开通阻塞血管后,因心肌缺血再灌注损伤而很难达到满意的疗效。目的:观察骨髓间充质干细胞移植对大鼠心肌缺血再灌注损伤的修复作用。方法:取健康3周龄SD大鼠的骨髓细胞悬液,进行骨髓间充质干细胞体外扩增培养。受体SD大鼠接受骨髓间充质干细胞或无血清DMEM心肌注射1周后建立心肌缺血再灌注损伤模型,心肌缺血0.5h再灌注2h后测定血清乳酸脱氢酶水平、心肌组织总超氧化物歧化酶活力及丙二醛水平;采用缺口末端标记法检测心肌细胞凋亡情况;免疫组化法检测Bcl-2、Bax蛋白的表达变化。结果与结论:分离培养的骨髓间充质干细胞增殖旺盛,纯度较高,且均质性和稳定性好;与缺血再灌注组相比,细胞移植组乳酸脱氢酶的漏出减少,总超氧化物歧化酶活性增加,丙二醛含量减少(P<0.01);细胞移植组心肌细胞凋亡指数显著低于缺血再灌注组(P<0.01);细胞移植组Bcl-2蛋白表达高于缺血再灌注组(P<0.05),Bax/Bcl-2比值低于缺血再灌注组(P<0.05)。结果表明骨髓间充质干细胞移植对大鼠心肌缺血再灌注损伤的修复可起促进作用。

BACKGROUND：Blocked blood vessels were opened following acute myocardial infarction with thrombolysis or intervention method. It is difficult to reach a satisfactory outcome due to myocardial ischemia/reperfusion injury. OBJECTIVE：To observe the repair effect of bone marrow mesenchymal stem cells （BMSCs） transplantation on myocardial ischemia/reperfusion injury in rats. METHODS：BMSCs were cultured and expanded from healthy 3-week-old Sprague-Dawley rats in vitro. Recipient Sprague-Dawley rats were injected with BMSCs or serum-free DMEM. 1 week later,rat models of myocardial ischemia/reperfusion injury were established. Following myocardial ischemia for 0.5 hour and reperfusion for 2 hours,serum lactate dehydrogenase （LDH） activity,total superoxide dismutase （TSOD） vitality and malondialdehyde （MDA） levels of myocardial tissue were measured. Cell apoptotic index was examined by terminal deoxynucleotidyl transferase-mediated d-UTP nick end labeling. The expressions of Bcl-2 and Bax proteins were measured by immunohistochemical technique. RESULTS AND CONCLUSION：BMSCs not only had a high purification,homogeneity and stability,but also had unlimited proliferation. Compared with ischemia/reperfusion group,LDH leakage was reduced,TSOD activity was increased and MDA levels were diminished in the BMSCs group （P 0.01）. Apoptotic index was significantly lower in the BMSCs group compared with ischemia/reperfusion group （P 0.01）. Bcl-2 expressions were greater in the BMSCs group compared with ischemia/reperfusion group （P 0.05）,but the Bax/Bcl-2 ratio in the BMSCs group was lower than the ischemia/reperfusion group （P 0.05）. Results suggest that BMSCs transplantation can promote cell proliferation of rats with myocardial ischemia/reperfusion injury.