miR-17-92在急性肝脏损伤中的功能和作用

The function and role of mi R-17-92 on acute liver injury

目的利用体外细胞模型和基因敲低模型评价miR-17-92在急性肝脏损伤中的作用。方法利用慢病毒LV-miR-17-92感染正常人肝细胞系L02,获得稳定过表达miR-17-92肝脏L02细胞,利用四氯化碳模拟肝细胞损失,MTS法检测miR-17-92高表达L02细胞和对照细胞的存活率。利用Alb-cre转基因小鼠和miR-17-92-loxp转基因小鼠杂交,获得肝脏组织特异的miR-17-92基因敲低小鼠。利用四氯化碳和伴刀豆球蛋白A,分别建立两种急性小鼠肝损伤模型。取肝脏组织进行HE染色,眼球取血检测谷丙转氨酶、谷草转氨酶,进而评价miR-17-92在急性肝脏损伤中的功能和作用。结果 Q-PCR结果显示慢病毒感染显著提高了L02细胞中miR-17-92的表达。MTS结果显示四氯化碳处理明显抑制了L02细胞的生长,而与对照组相比,miR-17-92过表达提高了四氯化碳处理后细胞的存活率(P<0.05)。基因组PCR结果和肝脏Q-PCR分析均显示肝脏特异miR-17-92基因敲低小鼠肝脏中miR-17-92的表达显著降低。小鼠腹腔四氯化碳给药能够显著诱导野生型小鼠肝脏miR-17-92的水平,而基因敲低小鼠中miR-17-92表达无明显变化。在四氯化碳和伴刀豆球蛋白A肝脏损伤模型中,与对照组相比,miR-17-92肝脏特异性敲低小鼠的肝脏病理学损伤明显加重,提示miR-17-92可能参与了急性肝损伤的修复过程。结论肝脏损伤能够诱导miR-17-92表达增加,而miR-17-92过表达对四氯化碳诱导的肝细胞损伤具有保护作用,miR-17-92敲除则加重了四氯化碳和伴刀豆球蛋白A诱导的急性肝损伤。因此,miR-17-92在急性肝脏损伤中起保护作用。

Objective To evaluate the effect of miR-17-92 on liver injury by establishing in vitro cell model and gene-knockout mice model.Methods Human liver cell L02 was infected by lentivirus LV-miR-17-92 and then lentivirus-mediated miR-17-92 stable overexpression human liver cells were harvested. Liver cell injury was simulated by CCl_4. Cell livability was detected using MTS method. The hepatocyte-specific miR-17-92 knockout mice were generated by hybriding the Alb-cre transgenic mice and miR-17-92-loxp transgenic mice. Two type of acute liver injuries in mice were induced with CCl_4 and Con A. Liver tissue was stained by HE staining. ALT and AST were detected in blood serum through eye ball removing. At last, the function and effect of miR-17-92 on liver injury was evaluated. Results Q-PCR test showed that the infection of lentivirus improved the expression of miR-17-92 in L02 cells. MTS test showed that CCl_4 suppressed the growth of L02 cells and miR-17-92 overexpression increased the survival rate of L02 cells injured by CCl_4（P〈0.05） as compare with control. Both genome PCR test and liver tissue Q-PCR analysis demonstrated that the miR-17-92 expression of hepatocyte-specific miR-17-92 knockout mice was observably suppressed. Enterocoelia injection of CCl_4 remarkably increased the expression level of miR-17-92 in liver, but the change was not obvious in hepatocyte-specific miR-17-92 knockout mice. In liver injury models, the liver pathological injury of hepatocyte-specific miR-17-92 knockout mice was more potent than that of the control, suggesting that miR-17-92 probably participated in the repair of acute liver injury. Conclusion Liver injury increases the miR-17-92 expression level and overexpression of miR-17-92 protects the liver cells from CCl_4 injury. The ablation of miR-17-92 aggravates the injury caused by CCl_4 and Con A. Therefore, miR-17-92 plays a positive role of protecting the liver from injury.