miR-155、AUF1转录后修饰SOD1调控燃煤型砷中毒肝损伤的分子机制

Endemic arsenism caused by coal-burning is a special geochemical disease.It is main damage to liver and skin.The toxic mechanisms are unclear,which is its bottlenecks and difficulties in prevention and control.At the same time,it is also an urgent need to solve the key problem.The oxidative stress is one of the widely accepted mechanisms.The subject group’s previous research has found that arsenic can affect the post-transcriptiona mechanisms of SOD1,which decreases its protein expressions and enzyme activities, nevertheless,the mechanisms are still unclear.The 3’UTR is considered as the key component of post-transcriptional regulation.The miRNAs and RNA-binding protein 1（AUF1）can specially bind 3’UTR of target gene mRNA.It can induce target gene mRNA degradation and translation inhibition,which can regulate gene expressions in post-transcriptional level.The research selects a unique arsenic poisoning population caused by coal-burning in Guizhou province.At the same time,we use sodium arsenite to duplicate liver injure model of rats after trasfecting livers applying lentivirus.In the meantime,we upregulate and downregulate respectively special gene expressions in vitro experiment adopting techniques of firefly luciferase reporter gene vectors and cotransfections.The research can explore regulating roles and mechanisms in post-transcriptional level that miR-155 and AUF1 regulate SOD1.The purpose of the study is aims to expound reasons and mechanisms of SOD1 low expressions,and provide new means and strategies in mechanism study and prevention and control measures of arsenism.

燃煤污染型地方性砷中毒是我国特有的一种地球化学性疾病，以肝脏和皮肤损害为主，毒作用机制不明是其防治工作的瓶颈与难点，也是亟待解决的关键问题。氧化应激是其主要机制之一，前期研究发现，砷能通过转录后作用下调SOD1蛋白表达和酶活力，但机制尚不清楚。3’UTR是转录后调控的关键元件，miRNAs和RNA结合蛋白1（AUF1）能与靶基因mRNA3’UTR结合，诱导mRNA降解或翻译抑制，在转录后水平调控靶基因表达。本项目以此为切入点，选择燃煤污染型砷中毒病型资源，结合慢病毒转染动物后的砷中毒大鼠肝损伤模型，并采用荧光素酶报告基因载体和共转染等技术上调和下调相关基因表达后的细胞实验，从转录后调控角度探讨miR-155、AUF1对SOD1的调控作用和机制，旨在揭示砷中毒抗氧化酶基因SOD1蛋白低表达的原因和机制，为砷中毒的机制研究和防治措施提供新的手段和策略。

地方性砷中毒肝损伤病情较为严重，毒作用机制不明是其防控工作的难点和瓶颈；抗氧化酶的基因转录后调控是其重要机制，miRNAs和AUF1能与靶基因mRNA 3’UTR结合，从转录后水平调控靶基因表达。本项目通过构建不同浓度亚砷酸钠致大鼠肝损伤模型，结合尾静脉注射腺相关病毒转染动物后高/低表达相关基因；并采用双荧光素酶报告基因载体和共转染等技术上调和下调相关基因表达后的细胞实验，从转录后调控角度探讨miR-155、AUF1对SOD1的调控作用；该机制尚在贵州省特有的燃煤污染型砷中毒人群进行验证。研究发现：亚砷酸钠暴露可降低AUF1的转录和蛋白表达，减少对Dicer1的抑制作用，从而促进miR-155高表达后，靶向结合SOD1-3′UTR，进而抑制SOD1蛋白表达和酶活力后诱导肝损伤。该研究在一定程度上揭示了砷中毒抗氧化酶基因SOD1蛋白低表达的原因和机制，为砷中毒的机制研究和防治措施提供新的手段和策略。该项目已发表科研论文7篇（SCI论文3篇，核心期刊论文4篇），已录用待发表论文1篇，获得实用新型专利1项；培养硕士研究生3名。