小鼠心脏移植缺血再灌注诱导细胞凋亡的机制

Apoptosis and its modulation of mouse heart following reperfusion of heart transplantion

目的研究小鼠心脏移植缺血再灌注后心肌细胞凋亡及其调控机制。方法建立小鼠颈部异位心脏移植模型,选取健康C57BL/6小鼠,供心摘取后保存在4C保护液中4h,然后移植给同系(C57BL/6)小鼠,在移植心脏复跳后的不同时相切取供心:15,30,60,90,120min。TUNEL技术检测心肌组织细胞凋亡情况,免疫组化测定心肌Bcl-2、Bax蛋白的表达,半定量RT-PCR测定Caspase-3mRNA的相对含量。结果 细胞凋亡指数随再灌注时间延长而升高,同时Bax蛋白表达上调,Caspase-3mRNA含量增高。结论 心脏移植供心缺血再灌注损伤可以诱导心肌细胞凋亡,细胞凋亡的机制与Capase-3的表达增高有关,这一过程受Bcl-2家族的调控。

Objective To study the apoptosis and its modulation of mouse heart following reperfusion of heart trans-plantion Methods Mouse cardiac I/R injury model via cervical heterotopic heart transplantation was established. Donor (C57BL/6) hearts were harvested, stored in cardioprotective solution (4 C) for 4 hr, and then transplanted to syngeneic (C57BL/6) mice. Obtained the grafted hearts after reperfusion for 15, 30, 60, 90, 120min. In situ TUNEL was used to detect apoptotic myocytes of myocardium. Immunohistochemistry was employed for detection of Bcl-2 and Bax protein. RT-PCR was used in semiquantitative assess of the relative expression of mRNA for Cas-pase-3. Results Apoptotic index(AI) increased after reperfusion,reached to the peak at 120min after reperfusion. Immunohistochemistry analysis showed that Bcl-2 and Bax were weak positive in cardiomyocytes of normal hearts, Bax protein was significantly upregulated after reperfusion,the expression of Bcl-2 protein was not significantly changed at different phase thoughout the experiment. The results of semi-RT-PCR demonstrated that the level of mRNA elevated with the AI changes. Conclusion Myocardiocytes apoptosis is induced by the donor heart ischemic reperfusion (I/R) ,the mechanism is mediated by up-regulation of Caspase-3 and modulated by Bcl-2 fa-milies.