核浆钙振荡在肺血管内皮间质转化中的作用机制

Based on the experimental finding made by applicant about hypoxia-induced cytosolic calcium- independent nuclear calcium oscillations in pulmonary vascular endothelial cells and combined with the principal theory established by the applicant about calcium oscillation kinetics-regulated transcriptional activation/repression and gene expression, the project will reveal the underlying mechanisms of hypoxia-induced independent nuclear calcium oscillation selectively-regulated transcriptional activity and gene expression and its role in pulmonary endothelial-to- mesenchymal transition. We will also explore the effects and mechanism of mutated-STIM1 in triggering hypoxia-induced independent nuclear oscillation, and the pathophysiological significance of nuclear oscillation mediated by mutated-STIM1 in endothelial-to-mesenchymal transition and hypoxic pulmonary hypertension. Additionally, we will affirm the relevance between mutated-STIM1 abundance and severity degrees of pulmonary hypertension patients using the novel technique for detecting the mutated-STIM1 and wild-STIM1 abundance. This project will be expected to reveal novel mechanisms of hypoxic pulmonary hypertension-associated endothelial-to-mesenchymal transition, and to identity the new transcriptional factors in pulmonary hypertension, and thus provide new intervene targets for prevention and therapy of hypoxia pulmonary hypertension.

申请人预实验发现缺氧诱导肺动脉内皮细胞发生独立于胞浆钙信号的核浆钙振荡，本项目拟以此为基础并结合申请人已建立的钙振荡通过其动力学特征调控转录激活和基因表达的基本理论，深入探讨缺氧诱导的独立核浆钙振荡选择性调控肺动脉内皮间质转化相关转录激活/抑制以及特异性标记分子基因表达的机制；同时进一步揭示突变型STIM1在缺氧诱导独立核浆钙振荡的作用机理，以及突变型STIM1介导的核浆钙振荡在肺动脉内皮间质转化与缺氧性肺动脉高压中的意义。此外，还将采用申请人建立的突变型和野生型STIM1表达丰度检测方法，进行突变型STIM1与缺氧肺动脉高压患者的相关性研究。本项目的实施不仅可望为缺氧性肺动脉高压相关的内皮间质转化提供新的机制解释，而且可能获知参与肺动脉高压发病的新转录因子，从而为寻找新的干预靶点提供线索。

本项目系统观察并分析了缺氧诱导肺动脉内皮细胞产生的独立于胞浆钙信号的核浆钙振荡动力学特征，并运用人工核浆钙振荡模型探讨核浆钙振荡通过其持续时间调控肺动脉内皮间质转化相关转录激活以及特异性标记分子基因表达。同时，进一步揭示了缺氧诱导ADAR1与STIM1 mRNA前体序列结合增强，进而介导核浆钙振荡的发生机制，而抑制二者的结合可显著降低缺氧诱导的肺动脉内皮间质转化及肺动脉高压，该研究为缺氧肺动脉高压相关的内皮间质转化提供了新的理论解释。