脑卒中易感性相关微小RNA多态的筛选与功能研究

Stroke is a complex disease caused by environmental factors and genetic factors, which has become the first cause of disability and the second cause of death in the world. It is a research hotspot that how to select the stable biomarkers to predict the susceptibility and prognosis of the disease, and to improve the quality of life and prolong the survival time. In recent years, microRNA (miRNA) has been widely studied as a new kind of regulatory genes. Our previous study showed that functional SNPs in miRNA could be used as a biomarker to predict stroke prognosis. On this basis, our project aims to screen the functional SNPs in precursor/mature miRNA region, key genes in miRNA generation pathways and target genes of miRNAs, which are related to stroke susceptibility and prognosis. Meanwhile, based on the established large stroke cohort, we will explore the multiple miRNA SNPs alone or in combination with stroke susceptibility and prognosis, and comprehensively evaluate the genotype-phenotype relationships and the functions of related miRNA. Our project will further clarify the mechanisms of miRNA-related genes involved in the susceptibility and prognosis of ischemic stroke, and provide theoretical basis for individualized prevention/treatment, prognosis judgment and new drug development of ischemic stroke.

脑卒中是环境因素和遗传因素共同作用的复杂疾病，已经成为世界范围内第一位的致残原因和第二位的致死原因。如何选择稳定的生物标志物预测疾病的易感性和预后，并据此进行个体化治疗，以提高病人的生存质量，延长生存时间，是目前国际上的研究热点。近年来，微小RNA（miRNA）作为一种新的调控基因被广泛研究。申请者前期的研究结果显示，miRNA上的功能性SNPs可以作为生物标志物预测卒中的预后，本研究将在此基础上，筛选前体/成熟体miRNA区域、miRNA生成通路关键基因和miRNA靶基因与卒中易感性和预后可能相关的功能性SNPs，运用目前已建立的大样本卒中队列，通过两阶段设计探讨多个miRNA相关SNPs单独或联合与卒中易感性和预后的关系，综合评估基因型-表型关系，同时开展相关miRNA的功能学研究，阐述其影响卒中易感性和预后的分子机制，为卒中个体化防治、预后判断及新药研发提供理论依据。

本项目筛选微小RNA相关遗传变异，运用关联研究探讨多个微小RNA相关遗传变异与卒中易感性的关系，综合评估基因型-表型关系，同时开展生物信息学研究，阐述其影响卒中易感性的可能分子机制，为卒中个体化防治、预后判断及新药研发提供理论依据。在微小RNA生成通路关键基因中，我们发现PIWIL1基因rs10773771位点可以显著影响大动脉粥样硬化型卒中的发病风险，与携带TT/CT基因型相比，携带CC基因型者发生脑卒中的风险显著降低（OR:0.63,95%CI:0.46-0.86,P=3×10-3）。生物信息学研究显示，rs10773771可以明显改变PIWIL1基因的RNA二级结构和稳定性，同时可显著影响多个转录因子的结合亲和力。数量性状基因座的表达分析显示，rs10773771位点可以在多种组织中影响PIWIL1基因的表达水平。对于微小RNA基因及其调控区遗传变异，我们发现对于miR-143 rs4705342，携带TC/CC基因型较携带TT基因型者发生脑卒中的风险降低(OR:0.81,95%CI:0.69-0.96,P=0.014) 。对于miR-200b rs7549819，与携带TT基因型相比，携带CC基因型者发生脑卒中的风险显著降低（OR:0.72,95%CI:0.53-0.97,P=0.030）。