摘要
目的:探讨抗凋亡基因bcl-xL治疗大鼠急性心肌梗死的可行性。方法:实验于2004-02/2005-02在中山大学第二附属医院医学实验中心完成。建立大鼠急性心肌梗死模型,大鼠随机分为实验组和对照组各10只,实验组用腺病毒介导的方法将bcl-xL基因导入急性缺血大鼠的心肌,对照组仅用生理盐水代替;用免疫组化法半定量分析显示大鼠心肌抗凋亡基因bcl-xL蛋白表达水平,采用缺口末端标记技术和流式细胞仪评估大鼠心肌细胞是否发生凋亡及凋亡的程度。结果:16只大鼠进入结果分析。①4周后取心脏梗死区标本免疫组化检测bcl-xL蛋白表达,发现对照组心肌只有少数着色,而实验组的心肌组织大多数呈深棕色。半定量分析显示,实验组的心肌组织内bcl-xL蛋白表达阳性单位值明显高于对照组(19.66±4.62,8.89±2.16,t=-5.98,P<0.01)。②两组心肌组织中均检测到缺口末端标记技术阳性染色的凋亡细胞。③显微镜下计数,对照组心肌细胞凋亡指数明显高于实验组犤(18.19±4.15)%,(7.25±2.09)%,t=6.65,P<0.01犦。④流式细胞仪检测结果为实验组心肌缺血后转染bcl-xL基因细胞凋亡率为(6.79±1.98)%,而对照组的细胞凋亡率为(20.15±6.04)%,实验组出现明显低于对照组的凋亡峰。结论:转染bcl-xL基因后在心肌组织内有高效的bcl-xL蛋白表达,心肌细胞凋亡指数明显减少,流式细胞仪检测到的细胞凋亡峰明显降低,而未转染bcl-xL基因的心肌细胞因缺血缺氧出现大量的凋亡细胞,细胞凋亡峰显著增高,表明心肌细胞通过转染bcl-xL基因,虽然没有完全阻断细胞凋亡,但大大提高了抗凋亡能力。同时心肌细胞的抗缺血、缺氧和抗损伤能力明显增强,提示转染bcl-xL基因通过其抗凋亡作用能明显提高心肌细胞在缺氧条件下的生存能力。
AIM:To investigate the feasibility of anti apoptotic gene bcl xL in treat ing rats with acute myocardial infarction. METHODS:The experiment was carried out in the Medical Experimental Center of the Second Affiliated Hospital of Sun Yat sen University from February 2004 to February 2005.Rat models of acute myocardial infarction were established,and th en they were randomized into study group(n=10) and control group(n=10).In the st udy group,bcl xL gene was introduced into the acute ischemic myocardium of rat s with the method of adenovirus mediation,and it was replaced by saline in the c ontrol group.The expression level of myocardial anti apoptic gene bcl xL pro tein of rats was detected with immunohistochemistry and semi quantitative anal ysis,and the occurrence of apoptosis and the severity of apoptosis in the cardia c myocytes of rats were evaluated with nick end labeling and flow cytometry. RESULTS:Sixteen rats were involved in the analysis of results.① Four weeks l ater,the expression of bcl xL protein in infarcted area of cardiac myocytes de tected by immunohistochemistry showed that only a few cardiac myocytes in contro l group were stained,and most cardiac myocytes were dark brown in study group.Th e results of semi quantitative analysis showed that the positive unit of posit ive bcl xL protein in myocardial tissue was obviously higher in the study grou p than in the control group(19.66± 4.62,8.89± 2.16,t=- 5.98,P< 0.01).② Apopt ic cells with positive staining were detected by nick end labeling in the myocar dial tissues of rats in both groups.③ Counting under microscope showed that myo cardial apoptic index in the control group was obviously higher than that in the study group[(18.19± 4.15)% ,(7.25± 2.09)% ,t=6.65,P< 0.01].④ The detected results of flow cytometer showed that the apoptic rate of transfected bcl xL g ene after myocardial ischemia in the study group and control group were(6.79 ± 1.98)% and(20.15± 6.04)% respectively,the apoptic peak was obviously lower in the study group than in the control group. CONCLUSION:There is high effective expression of bcl xL protein in the myoc ardial tissue after transfection of bcl xL gene,the myocardial apoptic index i s obviously decreased,apoptic peak detected by flow cytometer is markedly decrea sed;But in the cardiac myocytes without transfection of bcl xL gene,there are plenty of apoptic cells caused by ischemia and hypoxia,the apoptic peak is signi ficantly increased,it is indicated that although cardiac myocytes do not block a poptosis completely through transfection of bcl xL gene,but greatly improve th e ability against apoptosis,also obviously enhance the ability against ischemia, hypoxia and injury,which indicates that transfected bcl xL gene can obviously improve the living ability of cardiac myocytes under the condition of hypoxia th rough its anti apoptic effects.
出处
《中国临床康复》
CSCD
北大核心
2005年第19期24-25,共2页
Chinese Journal of Clinical Rehabilitation
基金
卫生部科研基金资助项目(981093)~~
