目的 研究脂滴自噬在HCV核心蛋白下调沉默信息调节因子1(SIRT1)诱导小鼠肝脂肪变性中的作用.方法 小鼠随机分为两组,每组10只.实验组小鼠尾静脉注射HCV core重组表达载体.对照组小鼠尾静脉注射磷酸盐缓冲溶液.1个月后处死小鼠.检测肝功能、脂联素、血清和肝内甘油三酰(TG)、肝脏组织病理学检查肝脂肪变性程度.蛋白质免疫法检测肝脏SIRT1蛋白、脂联素受体(AdipoR)蛋白以及脂滴自噬相关蛋白微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)、脂肪分化相关蛋白(ADRP)、尾部作用蛋白(TIP 47)和P62蛋白的表达.计量资料采用t检验.结果 与对照组相比,HCV组小鼠出现肝脂肪变性;肝脏TG含量明显增加[(80.9±20.1)比(45.8±10.5) μg/mg,t=4.964,P＜0.01];血清脂联素[(1.05±0.25)比(1.41±0.45) ng/mL,t=2.211,P＜o.05]水平下降;SIRT1蛋白水平(o.4±o.1比0.9±0.2,t=7.071,P＜0.01)和AdipoR2蛋白水平(0.4±0.1比0.8±0.2,t=5.656,P＜0.01)下降;LC3-Ⅱ蛋白(0.8±0.2比0.4±0.1,t=5.656,P＜0.01)、TIP-47蛋白(0.9±0.3比0.4±0.1,t=5.000,P＜0.01)和ADRP蛋白(0.8±0.3比0.4±0.1,t=4.000,P＜0.01)表达增加;而p62蛋白(0.7±0.2比0.8±0.3,t=0.877,P＞0.05)表达水平差异无统计学意义.结论 HCV核心蛋白下调SIRT1表达,下调脂联素及受体表达,引起不完全脂滴自噬导致肝脂肪变性.%Objective To investigate the effect of lipophagy on hepatitis C virus (HCV) core protein induced hepatic steatosis via down-regulating silent information regulator 1 (SIRT1) in mice.Methods Mice were randomized into HCV group and control group (n =10 in both groups),with injection of HCV core recombinant expression vectors or sterile phosphate buffered solution (PBS) through the tail vein,respectively.All mice were sacrificed in 1 month after the injection.Liver function and serum adiponectin were collected.Total triacylglycerol (TG) were measured in both serum and liver tissues.Levels of SIRT1 protein,adiponectin receptor 2 (AdipoR2) protein,light chain 3-Ⅱ (LC3-Ⅱ) protein,adipose differentiation related protein (ADRP),tail interacting protein 47KD (TIP-47) and P62 protein in liver were measured using western blot.Quantitative data was analyzed using t-test.Results In HCV group,histopathological examinations revealed hepatic steatosis,and the hepatic TG content (80.9 ± 20.1 vs 45.8 ± 10.5 μg/mg,t =4.964,P＜ 0.01) and levels of LC3-Ⅱ protein (0.8±0.2 vs0.4±0.1,t =5.656,P＜0.01),TIP-47 protein (0.9±0.3 vs0.4±0.1,t =5.000,P＜0.01) and ADRP protein (0.8 ± 0.3 vs 0.4 ± 0.1,t =4.000,P＜0.01) were all increased than those in the control group.However,serum adiponectin (1.05 ± 0.25 vs 1.41 ± 0.45 ng/ml,t =2.211,P＜0.05),SIRT1 protein (0.4 ± 0.1 vs 0.9± 0.2,t =7.071,P＜0.01) and AdipoR2 protein (0.4 ± 0.1 vs 0.8 ± 0.2,t =5.656,P＜0.01) were decreased in HCV mice group compared with those in control group.Expression of P62 protein (0.7 ± 0.2 vs 0.8 ± 0.3,t =0.877,P＞0.05) showed no significant difference between the two groups.Conclusion HCV core protein might cause hepatic steatosis via inducing incomplete lipophagy through down-regulating the expression of SIRT1,adiponectin and AdipoR2.
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