基于miRNA的无症状颅内动脉狭窄人群缺血性卒中易感性研究

Stroke has brought great disaster to us, and lots of work has been done on risk factors of stroke and its prevention. Intracranial artery stenosis (ICAS) is one of the most common causes of ischemic stroke in Asia. Lifestyle factors and traditional risk factors for cardiovascular diseases are important promoters for stroke. However, in patients with asymptomatic ICAS, it is still quite difficult to determine the high-risk ones for stroke. MicroRNAs are short non-coding RNAs, whose main function is to regulate gene expression by hindering the translation of specific miRNAs at the post transcriptional level. MicroRNAs can either induce the degradation of its target mRNA or, most frequently, prevent its translation into proteins. Previous studies have paid attention to miRNAs as disease biomarkers. Based on baseline information in our previous study, we will follow up the patients (716 patients) with asymptomatic ICAS. Whole-genome miRNA expression profiles will be generated in asymptomatic ICAS patients with or without stroke, and normal controls. Representative differentially expressed miRNAs will be measured in all cases and controls by real-time PCR. Then target genes predictions and potential molecular mechanism exploratory from gene ontology and pathway analysis will be made. Differentially expressed miRNAs will be circulating biomarkers for predicting ischemic stroke in asymptomatic ICAS patients, which is useful for primary prevention.

卒中一直是困扰人类的主要疾病，人们一直在积极探索其有效的预防措施。颅内动脉狭窄是亚洲人群缺血性卒中的常见病因，行为生活方式和传统心脑血管危险因素无疑是卒中的重要推手，但仍难以筛选出无症状颅内动脉狭窄人群中高卒中风险的“易感患者”。MicroRNA（miRNA）是内源性非蛋白编码调控RNA，参与调节生物体内基因表达，研究显示其可作为多种疾病的生物标志物。我们针对前期研究建立的无症状颅内动脉狭窄人群(716例)，随访获取其卒中发生情况，通过miRNA芯片对发生和未发生缺血性卒中的颅内动脉狭窄患者、及无颅内动脉狭窄的健康人进行全基因组水平miRNA表达谱的鉴定，并应用RT-PCR验证，筛选出卒中组特异性表达的miRNA，借助功能分析软件及数据库进行miRNA功能分析，预测靶基因，寻找可能的机制。筛选出的miRNA将对缺血性卒中有早期预测价值，有助于识别高卒中风险的无症状人群，指导临床一级预防。

卒中是最主要的致死致残疾病，颅内动脉狭窄是亚洲人群缺血性卒中的常见病因，行为生活方式和传统心脑血管危险因素无疑是卒中的重要推手，但仍难以筛选出无症状颅内动脉狭窄人群中高卒中风险的“易感患者”。MicroRNA(mi RNA)是内源性非蛋白编码调控RNA，参与调节生物体内基因表达，研究显示其可作为多种疾病的生物标志物。我们针对前期研究建立的无症状颅内动脉狭窄人群(716例)，随访获取其卒中发生情况。依据4年随访结果，将缺血性卒中病例按年龄、性别1:1:1匹配无卒中的颅内动脉狭窄患者及无颅内动脉狭窄的健康人作为对照，采用miRNeasy Mini Kit进行冻存血样的血清total RNA抽提，抽提所得total RNA 经Agilent Bioanalyzer 2100电泳质检，排除各种信息不全者、血样缺如者、以及血标本有效剂量不够、质检标本不合格者，最终共14例ICAS人群缺血性卒中病例纳入研究，匹配无卒中的颅内动脉狭窄患者及无颅内动脉狭窄的健康人对照，共42例血样纳入分析，通过miRNA芯片对发生和未发生缺血性卒中的颅内动脉狭窄患者、及无颅内动脉狭窄的健康人进行全基因组水平miRNA表达谱的鉴定，将三组样本进行miRNA芯片差异分析，寻找差异miRNA：hsa-miR-320a，hsa-miR-1202，hsa-miR-1225-5p，hsa-miR-191-3p，在G1（有狭窄有卒中）比G2（有狭窄无卒中）中有差异上调；hsa-miR-486-5p，hsa-miR-92a-3p， hsa-miR-6090在G1（有狭窄有卒中）比G2（有狭窄无卒中）中是下调。依据6年随访(2016-2017年度)结果对研究对象分组，将ICAS人群缺血性卒中病例按1:1:1 匹配ICAS无脑梗死组、以及无ICAS无脑梗死组对照，进行ABI taqman探针法进行差异miRNA的RT-PCR定量验证，筛选出卒中组特异性表达的miRNA，借助功能分析软件及数据库进行miRNA功能分析。筛选出的miRNA将对缺血性卒中有早期预测价值，有助于识别高卒中风险的无症状人群，指导临床一级预防。