促红细胞生成素对脂肪肝大鼠模型肝脏缺血再灌注损伤凋亡基因bcl-2、bax mRNA表达的影响

Effect of erythropoietin on the mRNA expression of apoptosis genes bcl-2 and bax in rats with fatty liver disease after hepatic ischemia-reperfusion injury

目的探讨促红细胞生成素(EPO)对脂肪肝大鼠模型肝脏缺血再灌注损伤凋亡基因bcl-2、bax mRNA表达的影响。方法成年雄性SD大鼠100只,高脂饮食饲料喂养12周。造模成功后,软件法随机将脂肪肝大鼠平均分为5组,每组18只:假手术组(SHAM)组、缺血再灌注(IR)组、IR+EPO低剂量组(EPO-1组)、IR+EPO中剂量组(EPO-2组)、IR+EPO高剂量组(EPO-3组)。IR模型通过术中完全阻断肝中叶及左肝叶血流建立,造成70%大鼠肝脏缺血,缺血时间控制在80 min。各组于缺血80 min再灌注1、3、6 h三时相处死,RT-PCR法检测并比较肝组织中bcl-2、bax mRNA的表达水平。计量资料多组间比较采用单因素方差分析,进一步两两比较采用LSD-t法。结果与IR组相比,EPO-1、EPO-2、EPO-3组肝脏中bcl-2 mRNA表达水平在各时相(1、3、6 h)的表达水平均明显升高(P值均<0. 05); bax mRNA的表达水平均明显下降(P值均<0. 05)。SHAM组、EPO组肝组织中bcl-2/bax mRNA的比值在各时相(1、3、6 h)均显著大于IR组(P值均<0. 05)。结论 EPO对脂肪肝大鼠肝脏缺血再灌注损伤具有保护作用。其可能是通过促进抗凋亡基因bcl-2 mRNA的表达和抑制促凋亡基因bax mRNA的表达实现。高剂量EPO的抗细胞凋亡作用效果优于中低剂量。

Objective To investigate the effect of erythropoietin( EPO) on the mRNA expression of apoptosis genes bcl-2 and bax in rats with fatty liver disease after hepatic ischemia-reperfusion injury. Methods A total of 100 male adult Sprague-Dawley rats were fed with high-fat diet for 12 weeks. After the model was established,the rats with fatty liver disease were randomly divided into sham-operation( SHAM) group,ischemia/reperfusion( IR) group,IR + low-dose EPO group( EPO-1 group),IR + middle-dose EPO group( EPO-2 group),and IR + high-dose EPO group( EPO-3 group). The IR model was established by completely blocking the blood flow in the middle and left lobes of the liver to induce ischemia in 70% of the liver,with an ischemia time of 80 minutes. The rats were sacrificed at 1,3,and 6 hours of reperfusion after 80 minutes of ischemia,and RT-PCR was used to measure the mRNA expression of bcl-2 and bax in liver tissue. A one-way analysis of variance was used for comparison of continuous data between multiple groups,and the least significant difference test was used for further comparison between two groups. Results Compared with the IR group,the EPO-1,EPO-2,and EPO-3 groups had a significant increase in the mRNA expression of bcl-2 and a significant reduction in the mRNA expression of bax at each time point( all P < 0. 05). The SHAM group and the EPO groups had a significantly higher bcl/bax mRNA ratio than the IR group at each time point( all P < 0. 05). Conclusion EPO exerts a protective effect against hepatic ischemia-reperfusion injury in rats with fatty liver disease,possibly by promoting the mRNA expression of bcl-2 and inhibiting the mRNA expression of bax. High-dose EPO has a better effect than middle-and low-dose EPO.