肝细胞生长因子对辐射后心肌细胞蛋白合成的保护作用

目的 研究肝细胞生长因子(HGF)对60Coγ射线照射体外培养的大鼠心肌细胞蛋白表达的影响.方法 体外培养新生大鼠心肌细胞,分为未照射组、单纯照射组、HGF处理照射组,照射组细胞分别用60Coγ射线20Gy单剂量照射心肌细胞,HGF处理的照射组在照射前3 h用终浓度为40ng/ml的HGF孵育.在照射后48 h:(1)用蛋白检测试剂盒检测各组心肌细胞中的总蛋白含量;(2)流式细胞仪检测各组的细胞周期变化;(3)带绿色荧光蛋白基因的腺病毒(AdGFP)感染各组心肌细胞,感染后48 h用流式细胞仪检测各组心肌细胞中所含的绿色荧光蛋白的荧光强度,间接比较各组心肌细胞中绿色荧光蛋白的生成量.结果 照射后48h,照射组心肌细胞中总蛋白含量较未照射组减低(P＜0.01),HGF处理的照射组心肌细胞中总蛋白含量较单纯照射组增高(P＜0.05).照射后96 h、感染AdGFP后48 h,照射组心肌细胞的绿色荧光强度明显弱于未照射组(P＜0.01),HGF处理的照射组心肌细胞的绿色荧光强度较单纯照射组增强(P＜0.01).结论 60Coγ射线单剂量照射抑制体外培养的心肌细胞蛋白合成,HGF可部分逆转60Coγ射线对心肌细胞蛋白生成的抑制作用.

Hepatocyte growth factor enhances protein synthesis in cardiomyocytes exposed to gamma-ray irradiation

Objective To investigate the protective effect of hepatocyte growth factor (HGF) on protein synthesis in rat cardiomyocytes exposed to gamma-ray irradiation. Methods Primary cultured cardiomyocytes were irradiated with single-dose (20 Gy) gamma ray in the absence or presence of HGF (40 ng/ml) added in the cell culture 3 h before the exposure. Forty-eight hours after irradiation, the total cellular protein was measured and cell cycle analyzed by flow cytometry. The cardiomyoctes were also infected with AdGFP 48 h after irradiation and the fluorescence intensity of the green fluorescence protein (GFP) in the cells determined by flow cytometry 48 h after infection. Results The protein synthesis was decreased significantly in the irradiated cardiomyocytes as compared with the control group (P<0.01), but was remedied significantly by incubation of the cells with HGF before the exposure (P<0.05). Flow cytometry revealed much lower mean fluorescence intensity (MFI) of GFP in irradiated cardiomycytes than in cells without the exposure (P<0.01); The MFI was higher in HGF-treated cardiomyocytes than in cells without HGF treatment following the exposure (P<0.01). Conclusion Gamma ray irradiation inhibits protein synthesis in cardiomyocytes, and HGF may attenuate this effect of gamma ray exposure for cardiomyocyte protection.