CYP2E1启动子区单核苷酸多态性与环孢素诱导肝损伤相关性分子机制

Cyclosporine-induced liver injury, with approximate occurrence rate of 30% and significant difference of individual susceptibility, can lead to acute liver failure and even death. It has been confirmed that Cyclosporine can enhence the activity of CYP2E1 enzyme which is involved in the metabolisms of many pretoxicity chemicals and endogenous metabolites, with large numbers of reactive oxygen species being produced to result in lipid peroxidation and liver lesion, and CYP2E1 polymorphism is associated with alcoholic liver disease, HBV, liver carcinoma and other liver diseases. Besides, the expression can be down-regulated by miR-378. The results of our preliminary experiment revealed that one of nine CYP2E1-SNPs (rs3813866) was found to be strongly correlated with Cyclosporine-induced liver injury. So we hypothes that the treatment of CsA and the susceptibility of CYP2E1 gene polymorphism are both mediated by CY2E1, which might be regulated by miR-378, and then result in high risk of liver injury.The aims of this study are 1) to study the gene function of rs3913866 and the influence of Cyclosporine with hepatotoxicity to CYP2E1 mRNA levels, protein expression and activity in cells carrying susceptive mutations and make clear the impact of the mutations on the transcriptional activity of CYP2E1, 2) to investigate the regulation of miR-378 to the expression of CYP2E1, 3) to find susceptible SNP in promoter and potential biomarker that can be used for the early diagnoses of Cyclosporine-induced liver injury and new targets for its' treament. The results of this study will be helpful to avoid the occurrence of druge-induced liver injury events and it will also supply new ideas and new targets for the treatment.

环孢素诱导肝损伤发病率约为30%，个体间易感性差异大，严重时可致急性肝衰竭甚至死亡，但其发病机制尚不清楚。环孢素可增强CYP2E1活性，通过氧化应激机制产生肾毒性；已证实CYP2E1基因多态性与酒精性肝病、肝癌等多种肝脏疾病相关；前期实验发现CYP2E1启动子区存在与环孢素诱导肝损伤强关联的SNP位点。本课题在此基础上提出CYP2E1该位点基因突变和环孢素均可能通过上调CYP2E1转录表达，介导氧化应激，导致肝损伤，miR-378可反馈性下调CYP2E1表达活性的假说。本研究拟从细胞水平探索CYP2E1 和miR-378基因功能及环孢素对其影响，在动物和人体水平进行氧化应激、CYP2E1表达以及miR-378对其调控作用研究，以期阐明CYP2E1启动子区SNP多态性在环孢素诱导肝损伤发病过程中的分子机制，为发现药物性肝损伤早期诊断生物标志物和临床治疗新靶点提供科学依据。