miR-320家族在主动脉夹层血管重构中的作用及机制研究

Aortic dissection (AD) is a life-threatening disease with high mortality in both early phases and in the long term especially in thoracic aortic dissection. We reported differentially expressed proteins and differentially expressed microRNAs(miRNAs) profiles of the aorta between AD patients and normal controls in our previous studies, which provide important information for the vascular pathological remodeling of AD. Among the differentially expressed miRNAs, the expression of miR-320 family including miR-320a,320b,320c and 320d decreased significantly compared with the normal control. We construct the miR-320 sponge transgenic mice and induced aortic dissection by angiotensin Ⅱ infusion and high fat diet in the transgenic mice and wild type mice. We found that the morbidity of aortic dissection was higher in the miR-320 sponge trangenic mice than that in the wild type mice.The results suggested that miR-320 family may play important roles in the vascular pathologic remodeling of AD, which deserve further research. In this program, we plan to discover the possible target gene and proteins of miR-320 by using ITRAQ proteomics, gene expression array, molecular biology and bioinformatic technique and et al. Then we will investigate the molecular pathogenesis of miR-320 family in AD in vivo and in vitro. The value of miR-320 as the target of interfering the process of AD will also be evaluated by techniques of miRNA overepression or knockdown as well as miRNA sponge. The resluts of this program will help give further new insight into the pathogenesis of AD and provide new possible target moleculars for early diagnosis or prevention and treatment for AD.

主动脉夹层（AD）破裂死亡率极高，严重威胁患者生命。我们前两个课题通过蛋白质组学和miRNA芯片等发现AD患者胸主动脉中膜差异表达蛋白和miRNAs，它们在AD血管病理性重构中可能具有重要作用，其中miR-320家族在AD中表达较对照组明显降低，应用miR-320 sponge转基因小鼠诱导AD较野生型小鼠更易发生夹层。本项目拟延续前期研究，采用ITRAQ蛋白质组学、表达谱芯片、分子生物学及生物信息学等技术，筛选出与AD可能密切相关的miR-320家族的靶基因/蛋白，并在体内小鼠模型和体外细胞中探讨其作用机制；进而利用miRNA过表达/沉默及miRNA sponge等技术，探讨miR-320家族作为AD发病过程中的可能干预靶点的应用价值。本项目从上游基因调控到下游蛋白功能水平进行研究，为阐明AD的发病机理提供新思路，并为AD的早期防治、疾病转归和预后评估提供可能的新靶标。

主动脉夹层（AD）是累及主动脉的严重疾病，夹层一旦破裂，患者死亡率极高。此类疾病的发病机制尚不明确。课题组前期通过蛋白质组学和miRNA 芯片等发现了AD患者胸主动脉中膜差异表达蛋白和miRNAs，表明它们在AD的发生发展中可能具有重要作用，其中miR-320 家族在AD中表达较对照组明显降低，应用miR-320 sponge 转基因小鼠诱导AD较野生型小鼠更易发生夹层。本课题在前期研究的基础上，采用ITRAQ 蛋白质组学、表达谱芯片、分子生物学及细胞免疫学检测等技术，对miR-320的效应蛋白，调控因子，以及作为AD治疗方法的可行性做了全面探讨。课题组首先扩充了临床样本量，证明了miR-320 表达降低与AD发生的相关性，并明确了平滑肌细胞中相关miRNAs的表达差异。其次，课题组探讨了miR-320潜在的靶基因位点，发现了miR-320效应因子HSP27在AD病程中的作用和机制。并且，课题组进一步深入研究了miR-320发挥作用的分子信号通路，发现了巨噬细胞中MMPs通路对于AD发展的作用机理。再次，课题组构建了miR-320 sponge小鼠模型，研究了miR-320 对于防止主动脉破裂以及抑制炎症反应的作用机制。本课题的研究成果揭示了miR-320在AD发生发展中的作用及分子机制，并初步探明了miR-320作为靶点对于AD的治疗作用。这些结果为进一步明确AD的发病机理，开发新型治疗方法提供有力的理论依据。