microRNAs在线粒体融合蛋白-1介导的肺血管重构中的作用

The imbalance of pulmonary arterial smooth muscle cells (PASMCs) mitochondrial homeostasis induced abnormal proliferation is an important pathological process in the pulmonary hypertension, the molecular mechanism is unknown. We have found that hypoxia affect the form and functions of mitochondria, regulate the cell cycle progression, increase the cell proliferation and pulmonary vascular remodeling. We prove this hypothesis by the following research: 1). We performed animal models, cell biology and molecular biology to determine the mitochondrial function in pathogenesis of pulmonary hypertension and clarify the role of mitochondria fusion protein (Mfn1) in hypoxia induced PASMCs proliferation. 2) By bioinformatics we explore the role of miRNAs in hypoxia regulated Mfn1 expression and determining the key miRNA. 3) After overexpression or knock down miRNAs, we determine the regulation of miRNAs in PASMCs mitochondrial fusion process, cell cycle and cell phenotype by targets Mfn1. We determined the role of miRNAs in regulating mitochondrial fusion/fission in hypoxia by bioinformatics for the the first time. Provide a theoretical basis for the prevention and treatment of pulmonary vascular remodeling, providing new clues for the disease gene therapy.

线粒体稳态失衡导致的肺动脉平滑肌细胞(PASMCs)增殖是肺动脉高压疾病发生的重要病理过程，分子机制不明。我们假设缺氧引起线粒体形态功能改变调控细胞周期进程，促进细胞增殖导致血管重构。拟通过下述研究证明该假设：1). 通过动物模型，细胞生物学、分子生物学等方法确定肺动脉高压疾病发病过程中线粒体功能变化及缺氧对线粒体融合蛋白(Mfn1)表达的调控，阐明Mfn1在PASMCs增殖中的作用。2). 通过生物信息学和实验方法明确miRNAs在缺氧调控Mfn1表达中的作用，确定起关键作用的miRNA。3). 通过过表达或敲除miRNAs，分子生物学技术确定miRNAs调控的Mfn1对线粒体融合过程及 PASMCs细胞周期，表型的影响。首次将miRNAs应用于缺氧对PASMCs线粒体融合/分裂的调控研究，为肺血管重构的防治提供理论依据，为疾病基因治疗提供新的线索。

肺动脉高压疾病是一类以血管重构为病理改变的恶性心血管系统疾病。线粒体稳态失衡导致的肺血管重构特别是肺动脉平滑肌细胞(PASMCs)增殖是肺动脉高压疾病发生的重要病理过程，分子机制不明。我们的研究发现缺氧引起线粒体形态功能改变并通过多种途径调控细胞周期进程，促进细胞增殖导致血管重构。但是线粒体融合蛋白1（Mfn1）在肺循环中的作用、缺氧如何调控Mfn1未见报告。我们假设缺氧通过microRNA调控Mfn1，使线粒体形态、功能和信号转导系统等异常，导致肺血管增殖和重构。得到以下重要研究发现：1）缺氧上调Mfn1的表达、确定Mfn1对线粒体形态、功能的影响及在缺氧肺血管重构中的作用；2）明确Mfn1调控缺氧肺血管重构的信号转导系统、调控网络和关键分子；3）miR-125a在缺氧调控Mfn1中的作用和分子机制。本申请明确Mfn1在缺氧肺血管稳态失衡，重构中的作用和机制;发现治疗肺血管重构相关疾病的靶点。