PNPLA3基因1148M过表达的Huh7细胞中固醇调节元件结合蛋白-1c与甘油三酯的关系

Role of SREBP-lc in risk of liver disease associated with the triacylglycerol lipase PNPLA3 I148M variant

目的探讨PNPLA3基因1148M过表达的Huh7细胞中固醇调节元件结合蛋白（SREBP）-1c与甘油三酯的关系。方法用空病毒和携带PNPLA3基因1148M突变型的慢病毒感染Huh-7细胞，构建空病毒组（对照组）和PNPLA3基因1148M突变型组（突变组）。分别用油红O染色显示细胞内甘油三酯含量变化，用全自动生物化学分析仪测定各组细胞中甘油三酯及总胆固醇含量，荧光定量PCR测定SREBP—1 cmRNA的水平变化。Western blot检测SREBP—1c蛋白的表达情况。两组均数的比较采用t检验，指标间的关系判定用直线相关分析。结果油红O染色显示突变组中甘油三酯含量增加。突变组的甘油三酯和总胆固醇含量明显升高，分别为（0．54±0．03）mmol／L和（0．28±0．03）mmol／L，高于对照组的（0．23±0．02）mmol／L和（0．13±0．02）mmol／L（t值分别为22．58和11．83，P值均〈0．01）。SREBP—1cmRNA表达量增加，与对照组相比的差异具有统计学意义泸〈0．01）。SREBP—1c蛋白也较对照组有所增加。突变组SREBP—1c水平与甘油三酯水平呈正相关（r=0．912，P〈0．01）。结论PNPLA3基因1148M多态性可促进脂肪合成增加，其中甘油三酯的合成增加可能通过SREBP—1c起作用，这为探讨非酒精性脂肪性肝病的发病机制提供了新线索。

Objective To investigate the relationship between SREBP-lc and the risk of liver disease associated with the triacylglyceride lipase PNPLA3 I148M variant using a human hepatoma cell line model transfected with recombinant lentiviruses. Methods Huh7 cells were transfeeted with control lentivirus or lentivirus containing the PNPLA3 I148M variant （variant）. The two cell groups were compared to assess differences in triglyceride content （using oil red O staining）, levels of triglyceride and cholesterol （using automated biochemical analyzer）, expression of SREBP-1c mRNA （using fluorescence quantitative PCR）, and expression of SREBP-1c protein （using western blot. Results Cells expressing the PNPLA3 I148M variant showed higher triglyceride content （0.54 ± 0.03 mmol/L vs. control cells： 0.23±0.02 mmol/L; t = 22.58,P 〈 0.001）, cholesterol level （0.28 ± 0.03 mmol/L vs. control cells： 0.13±0.02 mmol/L; t = 11.83, P 〈 0.001）, SREBP-1c mRNA expression （13.59 ± 0.60 vs. 11.81 ± 0.82; [The abstract and text in the paper say variant increases, but the data shown says the higher value is in the control cells. Please correct to properly express the data.] P = 0.001）, and SREBP-le protein expression. The level of SREBP-1c was positively correlated with serum triglyceride in the cells expressing the PNPLA3 I148M variant （1- = 0.912, P 〈 0.01）. Conclusion The risk of liver disease associated with the PNPLA3 I148M variant, which increases lipogenesis, may involve SREBP-1 c and a pathway that increases triglycerides.