中文摘要：

目的 探讨靶向持续抑制磷酸二酯酶5（PDE5）的短发夹RNA（shRNA）[PDE5 shRNA]重组腺病毒载体对小鼠急性心梗后早期细胞凋亡的影响。方法 结扎小鼠左冠状动脉前降支建立小鼠心肌梗死模型,随机分为实验组10例,将携带有PDE5 shRNA重组腺病毒载体注射到心肌梗死区及周边区和对照组10例,将没有插入PDE5 shRNA的普通腺病毒载体注射到心肌梗死区及周边区。1周后,进行免疫组化和原位末端标记分析（TUNEL）检测梗死及梗死周边细胞凋亡情况,酶联免疫吸附实验（ELISA法）检测环磷酸鸟苷（c GMP）和蛋白激酶G（PKG）的表达,蛋白印迹分析检测各组PDE5的表达情况。结果 心梗1周后,和对照组相比较,实验组小鼠梗死区及梗死周围区域细胞凋亡明显减少（P〈0.05）,梗死周边心肌细胞凋亡明显减少（P〈0.05）,实验组小鼠心肌PDE5表达明显减少,c GMP和PKG表达明显上调（P〈0.05）。结论 PDE5 shRNA的干预可以明显减少心肌梗死及梗死周边区细胞凋亡和非梗死区心肌细胞凋亡,可能与上调c GMP和PKG的表达密切相关。

英文摘要：

Objective To study the impact of adenoviral short hairpin RNA （shRNA） targeting phosphodiesterase 5 （PDE5 shRNA） on myo- cardial cells apoptosis at early stage post - myocardial infarction （MI）. Methods MI was induced in mice by left coronary artery ligation. Mice were randomly assigned to test group [ n = 10, adenoviral vectors inserted with shRNA sequence for the inhibition of phosphodiesterase 5 （ PDE5 ） were injected intramyocardially to infarcted and border area ] and control group （n = 10, injection with adenoviral vectors without therapeutic PDE5 shRNA）. One week post - MI, apoptosis was evaluated by TdT-mediated dUTP nick - end labeling （TUNEL）, proteins were extracted from the left ventrieular of heart, level of PDE5 expression was detected using Western Bloting, the level of guanosine 3＇;5＇ - cyclic phosphate （cGMP） or protein kinase G （PKG） activity in the left ven- tricular of heart was evaluated by enzyme linked immunosorbent assay （ELISA）. Results One week post- MI, compared to control group, test group had reduced number of apoptotic cells in infarct and periinfarct areas, and significantly reduced cardiomyocytes apoptosis in the periinfarct regions （P 〈 0. 05 ）. Compared to control group, the level of PDE5 was significantly decreased and the levels of cGMP and PKG were significantly increased in the test group （P 〈 0. 05 ）. Conclusion It the PDE5 shRNA has protective effect on acute myocardial infarction and significantly inhibit the apopto- sis of myocardial cell which may be closely related to the increased expression of cGMP and PKG.