中文摘要：

目的观察磷酸二酯酶5（PDE5）shRNA对缺氧缺糖条件下乳鼠心肌细胞的保护作用。方法培养新生C57BL／6J小鼠心肌细胞，通过缺氧缺糖建立小鼠心肌细胞缺氧缺糖损伤模型。随机分2组：实验组（shPDE5）通过构建PDE5shRNA，将PDE5shRNA转染心肌细胞；对照组（Null）：将普通腺病毒载体转染心肌细胞。用原位末端标记分析（TUNEL）检测2组细胞凋亡情况；免疫蛋白印迹检测PDE5蛋白的表达；用酶联免疫吸附法测定各组心肌细胞cGMP和PKG的水平。结果与对照组比较，实验组PDE5表达明显下降，cGMP和PKG的活性明显上调（P〈0．05）；实验组细胞凋亡数明显减少（P〈0．05）。结论PDE5shRNA可明显拮抗缺氧缺糖诱导的心肌细胞凋亡，可能与PDE5shRNA持续抑制心肌细胞PDE5基因表达、显著上调cGMP和PKG活性有关。

英文摘要：

Objective To study the protective effects of PDE5 shRNA on cardiomyocytes cultured under oxygen glucose deprivation. Methods Cardiomyocytes were isolated from neonatal C57BL/6J mice. Cardio- myocytes were randomly assigned to test group （shPDE5） ： transfection of cultured cardiomyocytes with adenoviral phosphodiesterase 5 （PDE5） short hairpin RNA （PDE5 shRNA）, and control group （Null） ： transfec- tion of cultured cardiomyocytes with adenoviral vector without therapeutic PDE5 shRNA. After oxygen and glucose deprivation （OGD） treatment, the apoptosis was evaluated by TdT- mediated dUTP nick -end labeling （TUNEL）, the level of PDE5 expression was detected by Western blot. The level of cGMP or PKG activity in the ceils was evaluated by enzyme linked immunosorbent assay （ ELISA ）. Results Compared to control group, the level of PDE5 was significantly decreased and the levels of eGMP and PKG were significantly increased in the test group. Conclu- sion The present study suggests the protective effects of PDE5 shRNA on cardiomyoeytes cultured under oxygen glucose deprivation, significant- ly attenuating cardiomyocyte apoptosis through possible activating cGMP/ PKG signaling pathway.