PDE5 shRNA对小鼠急性心梗后早期细胞凋亡的影响

Adenoviral Short Hairpin RNA Targeting Phosphodiesterase 5 Inhibits Myocardial Cells Apoptosis at Early Stage Post-MI

目的:探讨磷酸二酯酶5(PDE5)shRNA对小鼠急性心梗后早期细胞凋亡的影响。方法:通过结扎小鼠左冠状动脉前降支建立小鼠心肌梗死模型,并将建立好的模型随机分为实验组(n=10):将携带有抑制PDE5的shRNA(PDE5 shRNA)重组腺病毒载体对小鼠心肌组织多部位注射;模型组(n=10):将没有插入PDE5 shRNA的普通腺病毒载体对小鼠心肌组织多部位注射。1周后,进行免疫组化和TUNEL分析检测梗死及梗死周边细胞凋亡情况,ELISA法检测环磷酸鸟苷(cyclic guanosine monophosphate,c GMP)和蛋白激酶G(protein kinase G,PKG)的表达,免疫蛋白印迹分析检测各组磷酸二酯酶5(phosphodiesterase5,PDE5)的表达情况。结果:心梗1周后,和模型组相比较,实验组小鼠梗死区及梗死周边区域细胞凋亡明显减少(P<0.05),实验组小鼠心肌PDE5表达明显减少,cGMP和PKG表达明显上调(P<0.05)。结论:PDE5 shRNA可以明显减少梗死区及梗死周边区细胞凋亡,可能与上调cGMP和PKG的表达密切相关。

Objective： To study the impact of PDE5 shRNA on myocardial cells apoptosis at early stage post-MI. Methods：Myocardial infarction（MI） was induced in mice by left coronary artery ligation. Mice were randomly assigned to test group（n=10）, in which adenovirus vector with PDE5 sh RNA particles were injected along the anterior and posterior LV wall, and model group（n=10）, in which adenovirus vector without PDE5 shRNA particles were injected in the same manner. One week post-MI, apoptosis was evaluated using the TUNEL method, Proteins were extracted from the left ventricular of heart, level of PDE5 expression was detected using Western Bloting, and level of cGMP or PKG activity in the left ventricular of heart was evaluated using ELISA. Results： One week post-MI, compared to model group, test group had reduced number of apoptotic cells in infarct and periinfarct areas, and significantly reduced cardiomyocytes apoptosis in the peri-infarct regions（P〈0.05）. Compared to model group, the level of PDE5 significantly decreased and the levels of c GMP and PKG significantly increased in the test group（P〈0.05）. Conclusions： The present study suggests the protective effects of PDE5 sh RNA on acute myocardial infarction, significantly inhibiting myocardial cell apoptosis through possible activating cGMP/PKG signaling pathway.