血管紧张素Ⅱ及血管紧张素Ⅱ1型受体反义寡核苷酸对心肌细胞bax、bcl-2基因表达

Effect of AngiotensinⅡ and Angiotensin Ⅱ Type Ⅰ Receptor Antisense Oligonucleotide on bax?bcl-2 Gene Expression of Cultured Cardiac Myocytes

目的 探讨血管紧张素 (AngⅡ )及血管紧张素Ⅱ 1型受体 (AT1R)反义寡核苷酸 (AS ODN)对心肌细胞凋亡调节蛋白bax、bcl 2的影响。方法 将培养的乳鼠心肌细胞分为正常组、AngⅡ组、AT1R AS ODN组 :AngⅡ组用 10 - 6 mol/LAngⅡ刺激 2 4小时 ;AT1R AS ODN组在转染反义寡核苷酸后也用 10 - 6 mol/LAngⅡ刺激 2 4小时 ;正常组不予任何刺激。刺激 2 4小时后用免疫细胞化学方法观察AngⅡ及AT1R AS ODN对心肌细胞凋亡调节蛋白bcl 2、bax表达的影响。结果 与正常组相比 ,AngⅡ组心肌细胞bcl 2蛋白光密度值下降显著 (0 0 72 5± 0 0 0 65vs 0 0 975± 0 0 0 83 ,P <0 0 5) ,bax蛋白光密度值增加 (0 0 941± 0 0 0 42vs 0 0 82 3± 0 0 0 2 4,P <0 0 5) ;与AngⅡ组相比 ,AT1R AS ODN组bcl 2蛋白光密度值增加 (0 0 90 0± 0 0 0 16vs 0 0 72 5± 0 0 0 65,P <0 0 5) ,bax蛋白光密度值降低 (0 0 863± 0 0 0 19vs 0 0 941±0 0 0 42 ,P <0 0 5)。结论 AngⅡ可以诱导心肌细胞发生凋亡 ,而AT1R AS ODN可以逆转AngⅡ诱导的心肌细胞凋亡。

Objective Bax and bcl-2 have been specu lated as the regulating genes for apoptosis of cells. In apoptosis cells, the expression of bax protein was increased with bcl-2 protein decreased. This study is aimed to investigate the effects of Angiotensin Ⅱ (AngⅡ) and angiotensin Ⅱ type Ⅰ receptor antisense oligonucleotide(AT 1R-AS-ODN) on the bax and bcl-2 gene expression in cardiac myocytes. Methods The cultured ne onatal rat cardiac myocytes were treated with: Ang Ⅱ (10 -6 mol/L), or AT 1R-AS-ODN+Ang Ⅱ for 24 hours. Bax and bcl-2 gene expression were evaluated with immunocytochemistry. Results Comparted with control, the bcl-2 protein optical density (OD) in cardiac myocytes was decreased (0 0725±0 0065 vs 0 0975±0 0083, P<0 05), while bax protein OD increased(0 0941±0 0042 vs 0 0823±0 0024, P<0 05). Comparted to Ang Ⅱ treated cells, bcl-2 protein OD in AT 1R-AS-ODN treated cells was increased(0 0900±0 0016 vs 0 0725±0 0065, P<0 05), with bax protein OD decreased (0 0863±0 0019 vs 0 0941±0 0042, P<0 05). In the Ang Ⅱ treated cells bcl-2/bax ratio was <1, however, in AT 1R-AS-ODN treated cells the bcl-2/bax ratio was >1, indicating Ang Ⅱ promotes apoptosis in myocardial cells while AT 1R-AS-ODN blocks the apoptosis process induced by Ang Ⅱ. Conclusion Ang Ⅱ induce apopto sis of cardiac myocytes, however AT 1R-AS-ODN abolishes the apotosis incurred by Ang Ⅱ.