过表达MORC2通过下调p53含量抑制L02肝细胞脂肪变性

Over-expression of MORC2 attenuates steatosis in L02 hepatocytes by downregulating p53

目的研究过表达MORC2对人L02肝细胞脂肪变性程度的影响及可能机制。方法利用慢病毒转染技术在L02肝细胞中过表达MORC2,qRT-PCR及Western blot鉴定过表达效果后,对L02肝细胞进行脂肪变性诱导,测定细胞甘油三酯(triglyceride,TG)含量并比较过表达前后L02肝细胞的脂肪蓄积程度;利用芯片技术对过表达MORC2前后的基因表达谱进行检测与Pathway分析,筛选过表达MORC2时发生变化的通路并选择对脂代谢有调控作用的p53进行研究;Western blot检测在L02肝细胞脂肪变性诱导时过表达MORC2对p53蛋白含量的影响;在过表达MORC2的基础上对L02肝细胞过表达p53,qRT-PCR及Western blot鉴定p53过表达效果后,通过TG测定观察过表达p53对过表达MORC2改变的L02肝细胞脂肪蓄积程度产生的影响。结果 qRT-PCR及Western blot证明过表达MORC2成功;过表达MORC2的L02肝细胞在脂肪变性诱导后TG含量较MORC2正常表达的L02肝细胞明显降低(P<0.01);基因表达谱芯片及Pathway分析显示脂代谢调控相关的p53通路在过表达MORC2后发生变化;Western blot显示过表达MORC2后,L02肝细胞中p53蛋白水平在脂肪变性诱导前后均降低;qRT-PCR及Western blot验证p53过表达成功,且过表达p53可部分解除MORC2对L02肝细胞脂肪变性的缓解作用。结论过表达MORC2可通过下调p53从而缓解肝细胞脂肪变性。

Objective To investigate the effect of microrchidia family CW-type zinc finger 2 （MORC2） over-expression on steatosis of immortalized hepatocyte line L02 and explore the potential mechanism. Methods MORC2 was over-expressed in L02 hepatocytes by lentivirus transfection, and then examined by qRT-PCR and Western blotting. Intracellular triglyceride （TG） was measured to evaluate cellular steatosis. A microarray chip was adopted to analyze related signaling pathways in the MORC2 over-expression process. Over-expression of p53 in the MORC2-over-expressed L02 hepatocytes was confirmed by qRT-PCR and Western blotting, and the effect of p53 over-expression on lipid accumulation was observed by measuring TG. Results Both qRT-PCR and Western blot data validated that MORC2 was over-expressed in the transfected L02 hepatocytes. Steatosis was significantly alleviated by MORC2 over-expression （ P 〈 0.01 ）. The microarray chip data revealed that lipometabolism-related p53 pathway was changed after MORC2 over- expression. Western blot results demonstrated that p53 protein was down-regulated after MORC2 over- expression. Moreover, over-expression of p53 partially increased steatosis in the MORC2-over-expressed L02 hepatocytes. Conclusion MORC2 attenuates steatosis of I_02 hepatocytes partially by down-regulating p53 expression.