长链非编码RNA-MALAT1在缺氧肺动脉平滑肌细胞增殖中的作用及分子机制的研究

The most significant characterize of hypoxic pulmonary hypertension is the proliferation of pulmonary artery smooth muscle cells (PASMCs). However, the mechanism of hypoxia-induced PASMCs proliferation remains unclear. Long non-coding RNA (lncRNA) plays an important role in regulation of gene expression in epigenetic, transcriptional and post-transcriptional level, the diversity functions involves in most aspects of proliferation signaling, however, whereas lncRNA involves in hypoxia-induced PASMCs proliferation still uncertain. Previous research results suggest that the expression of lncRNA- metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was changed after hypoxia exposure. MALAT1 regulates the proteins expression which contributes to the proliferation of PASMCs. We hypothesis that MALAT1 was mediated the molecular and signaling transduction systems which involved in hypoxia-induced PASMCs proliferation. Following study was designed to confirm our hypothesis. First, investigate the expression and distribution pattern of MALAT1 in pulmonary hypertension patients and hypoxia exposure mouse models. Second, investigate the role of MALAT1 in PASMCs proliferation and the exactly pathway. Third, identify the exactly molecular mechanism, such as the target microRNAs; target proteins and the interaction network. The results of this study will reveal the new mechanism of MALAT1 in regulating PASMCs proliferation; and can provide potential therapeutic and pharmaceutical strategies for hypoxic pulmonary hypertension.

缺氧引起肺动脉平滑肌细胞（PASMCs）增殖是缺氧肺动脉高压的重要特征，但其分子机制仍不明确。长链非编码 RNA(lncRNA)可在表观遗传学、转录及转录后水平等多层面调控基因的表达，其功能多样性涉及和细胞增殖有关的诸多环节，但是否参与缺氧PASMCs增殖尚不清楚。我们的结果提示缺氧升高lncRNA-MALAT1表达，MALAT1参与调控PASMCs增殖相关蛋白的表达。提示缺氧可能通过MALAT1调控和增殖有关的分子及信号转导系统，引起PASMCs增殖。拟通过下述研究证明该假设：(1)肺动脉高压患者和小鼠模型的MALAT1表达及组织细胞分布特点；(2) MALAT1在缺氧PASMCs增殖中的作用和作用的具体环节；(3)MALAT1通过microRNAs，靶蛋白及蛋白质互作网络调控增殖的分子机制。研究结果将首次阐明MALAT1调控PASMCs增殖的新机制，为肺动脉高压提供治疗和药物研究靶点。

由于缺氧肺动脉高压的高发病率和高致死率，且目前临床上仍缺少治愈方法，其治疗目标只是延缓患者的症状或阻止病程进展。因此，揭示缺氧肺动脉高压的病因，找出潜在的治疗和早期诊断靶点，无疑是该领域迫切需要解决的关键科学问题。本项目结合lncRNA 作为最近的科学研究热点和相关研究技术，针对缺氧肺动脉高压这个疾病而提出。本课题研究计划要点有三点：（1）明确肺动脉高压lncRNA-MALAT1 表达特点及组织细胞分布，揭示缺氧对lncRNA-MALAT1 的调节作用；（2）明确MALAT1 在缺氧引起的PASMCs 细胞增殖中的作用；（3）MALAT1 调控肺动脉高压肺血管平滑肌增殖的下游靶蛋白及关键节点的研究。在这三年的资助期间，这三点研究计划均取得了一定的成果，该项目研究内容均按照项目书的研究计划执行。主要结果和关键数据包括：明确了缺氧对肺动脉高压患者及体外培养PASMCs 的lncRNA-MALAT1表达变化动力学特性。通过siRNA干扰lncRNA-MALAT1的表达，明确lncRNA-MALAT1参与缺氧诱导的PASMCs增殖和细胞周期进程的功能。通过生物信息学方法预测了lncRNA-MALAT1下游的microRNAs和蛋白质网络，利用分子实验明确lncRNA-MALAT1主要通过microRNA-206调节NOTCH3的表达，参与缺氧诱导的PASMCs增殖的分子机制；此外证实了lncRNA-MALAT1与FUS蛋白相互结合的现象。本项目首次揭示lncRNA 在肺动脉高压中的功能调节作用及其具体的分子机制，为肺动脉高压药物的研发提供新的靶点。目前已发表标注项目基金号发表SCI文章4篇，其中通讯作者和第一作者文章2篇；影响因子大于5分文章2篇。在投文章２篇，其中１篇目前处于修稿状态（Molecular Therapy，IF=7.001）。