miR-33、miR-758水平及遗传变异与冠状动脉粥样硬化易感性的分子流行病学研究

microRNAs is the key targets for early warning, diagnosis and treatment of diseases. Literatures and results of our pilot study showed that ABCA1, which was a key regulatory factor for cholesterol efflux in coronary artery and HDL synthesis, was highly related the pathogenesis of coronary artery atherosclerosis (CAA). miR-33 and miR-758, two ABCA1 targeted microRNAs, were detected recently in vivo. To the best of our knowledge, the associations between the genetic variations and levels of miR-33, miR-758 and CAA susceptibility have not yet been evaluated. Basing on the population samples which have been established previously, this study will be performed with a tw0-stage case-control study design. Logistic regression model, likelihood ratio test, multiple linear regression model, generalized multifactor dimensionality reduction (GMDR) and package 'haplo.stats' will be used to evaluate the associations of the genetic variations and levels of miR-33a and miR-758 with CAA susceptibility and to explore their effect on fasting HDL-C levels, as well as the gene-gene and gene-environment interactions. Next, luciferase reporter gene assay will be used to validate the regulatory function of the SNPs. These findings may provide us new insights into the risk prediction and personalized treatment of CAA and as well as future potential therapeutic targets.

microRNA是疾病重要的早期预警、诊断和治疗靶点。文献及前期研究表明，ABCA1是调控冠状动脉胆固醇逆向转运和HDL合成的关键因子，与冠状动脉粥样硬化（CAA）发生机制密切相关。miR-33和miR-758这两种在动物实验中新发现的靶向ABCA1基因的MicroRNA，在人群水平如何调控机体的病理改变以及CAA发生，其水平及相关遗传变异与CAA发生有无关联？尚未见报道。本研究拟在前期已经建立的人群基础上，采用两阶段、大样本病例-对照研究设计，logistic回归、似然比检验、多元线性回归、广义多因子降维法（GMDR）和haplo.stats等数据分析模型，研究miR-33和miR-758水平及遗传变异与CAA易感性之间的关联性及其交互作用，探讨它们对空腹HDL-C水平的影响，进一步通过荧光素酶基因报告系统进行功能学验证。研究结果可为CAA风险预警、个体化医疗及新药开发提供新的靶点。

冠状动脉粥样硬化性心脏病（简称冠心病）是临床常见病、多发病，发病率逐年上升，年轻化趋势日趋严重，已成为全球范围内成人死亡的重要原因。MicroRNA在血脂代谢、炎症与免疫、血管内皮损伤与修复等信号通路中均发挥重要的调控作用，基于MicroRNA时效性、保守性和特异性较强、易于检测等特点，可作为动脉粥样硬化潜在的早期预警、早期诊断和治疗靶点。本研究通过流行病学现场人群研究和实验室功能验证相结合的方法，系统研究了miR-33、miR-758水平、编码基因遗传变异与空腹HDL-C水平、冠心病易感性的关联性。对12个标签SNP （全部符合HWE平衡）进行了与冠心病易感性的统计学分析，结果发现，Mir33a rs6002527，Mir33a rs17379759，Mir33b rs4925115，Mir758 rs12435162，Mir758 rs7141987与冠心病易感性的关联具有统计学意义（P<0.05）；冠心病患者中血浆miR-33a、miR-33b和miR-758的水平明显高于它们在健康对照组人群中的水平（P <0.001）；血浆miR-33a、miR-33b和miR-758的水平与血浆HDL-C水平呈现明显负相关；在整体人群中，rs12435162（P= 0.009）和rs7141987（P= 0.048）与空腹血浆HDL-C水平呈显著性相关；在冠心病人群中，rs17379759与血浆TG水平显著性相关（P=0.029），rs4925115（P=0.018），rs10130838（P=0.032），rs12435162（P=0.030）与空腹血浆HDL-C水平呈显著性相关。我们对与冠心病易感性和中间表型空腹HDL-C水平均显著性相关的三个标签SNP（rs4925115、rs12435162和rs7141987）进行了荧光素酶报告基因的功能学实验初步验证。结果证实，三个标签SNP中的rs4925115和rs7141987的变异型等位基因与野生型等位基因相比，荧光素酶的活性差异均具有统计学意义（P<0.05），进一步证实了miR-33, miR-758基因遗传变异在冠心病发病过程中的作用和潜在的机制。研究结果为冠心病的早期风险预警、个体化医疗及新药开发提供新的靶点。