bcl-2基因转染对热应激心肌细胞的保护作用

The protective effect of bcl-2 gene transfection on heat stressed cardiomyocytes

目的 探讨bcl 2基因转染对热应激心肌细胞的保护作用。方法 用胰酶消化法分离培养Wistar大鼠乳鼠心肌细胞 ,使其暴露于 39℃、41℃和 43℃水浴进行热应激。用脂质体转染法将bcl 2基因转染入心肌细胞 ,用免疫组织化学法检测转染结果。用生物化学法测定bcl 2基因转染对热应激前、后心肌细胞培养液中乳酸脱氢酶 (LDH)活力的影响 ;用流式细胞仪 (FCM)测定bcl 2基因转染对热应激前、后心肌细胞凋亡率的影响 ;用台盼蓝染色法测定bcl 2基因转染对热应激前、后心肌细胞坏死率的影响。结果 经 39℃、41℃和 43℃热应激后 ,心肌细胞培养液中LDH活力明显增高 ,心肌细胞的凋亡率由 4.74%分别增加到 5 .12 %、16 .31%和 2 8.97% ,坏死率分别由 3.5 2 %、3.5 5 %、3.5 3%增加到 3.6 1%、5 .81%和 10 .80 %。bcl 2基因转染后 ,41℃和 43℃热应激引起的心肌细胞凋亡率明显降低 ,43℃热应激引起的心肌细胞培养液中LDH活力和心肌细胞坏死率也明显降低。结论 热应激可以引起心肌细胞损伤 ,细胞凋亡是热应激心肌细胞死亡的重要途径 ,bcl 2基因转染对热应激心肌细胞有保护作用。

Objective To study the protective effect of bcl 2 transfection on the heat stressed cardiomyocytes. Methods Neonatal rat cardiomyocytes were isolated with trypsin digestion method and exposed to waterbath of 39 ℃,41 ℃ and 43 ℃ respectively.bcl 2 was transfected into cardiomyocytes with lipofectamine transfection method and the effect of transfection was measured with immunohistochemistory.The activity of lactate dehydrogenase(LDH) in heat stressed cardiomyocyte medium before and after bcl 2 transfection were measured with biochemistry method,the apoptosis rate of cardiomyocytes with flow cytometry(FCM),the necrosis rate of cardiomyocytes with trypan blue dying method. Results After heat stress at 39 ℃,41 ℃ and 43 ℃,the activity of LDH in medium increased significantly,the apoptosis rate of cardiomyocytes increased from 4.74%(37 ℃) to 5.12%, 16.31% and 28.97% respectively.The necrosis rate of cardiomyocytes increased from 3.52% to 3.61%,from 3.55% to 5.81% and from 3.53% to 10.80% respectively.bcl 2 gene transfection made the apoptosis rate of cardiomyocytes at 41 ℃ and 43 ℃ heat stress decreased significantly,the LDH activity in medium and the necrosis rate of cardiomyocytes at 43 ℃ heat stress also decreased significantly. Conclusions Cardiomyocytes could be injured by heat stress and apoptosis was one of the main pathway of cardiomyocytes death caused by heat stress. bcl 2 transfection could protect the cardiomyocyte from heat stress induced injury.