硫化氢对肺动脉高压大鼠肺动脉内皮细胞炎症反应的调节作用及分子机制

Recently, great attention has been paid to the pulmonary vascular inflammatory response in the study of the mechanisms for pulmonary hypertension. Based on the applicant's previous studies on endogenous hydrogen sulfide and pulmonary hypertension, the present study is designed to investigate the changing profile of endogenous hydrogen sulfide pathway in the process of pulmonary vascular inflammatory response in monocrotaline-induced pulmonary hypertensive rats. By activating and inhibiting the endogenous hydrogen sulfide pathway, and examining the changes in pulmonary vascular inflammatory response in pulmonary hypertensive rats as well as the synthesis and secretion of inflammatory factors by pulmonary artery endothelial cells, the study is designed to elucidate the regulatory effect of endogenous hydrogen sulfide on pulmonary vascular inflammatory response in pulmonary hypertension. Furthermore, targeting on NF-κB pathway, the applicant aims to discover the signaling pathway by which hydrogen sulfide inhibits pulmonary vascular inflammatory response in pulmonary hypertension. Meanwhile, focusing on the NF-κB p65 cysteine 38 thiol group, the applicant is to examine the molecular mechanisms by which hydrogen sulfide inhibits pulmonary artery endothelial cell inflammatory response. The findings concerning the regulatory effect of endogenous hydrogen sulfide on the pulmonary vascular inflammatory response in rats with pulmonary hypertension and the mechanisms would greatly deepen the understanding of the inflammatory mechanisms for pulmonary hypertension and provide new research strategy for discovering therapeutic target for pulmonary hypertension.

近年来，肺血管炎症反应在肺动脉高压发病机制中的意义受到高度关注。本课题在申请者对内源性硫化氢与肺动脉高压的系列研究基础上，以野百合碱诱导肺动脉高压大鼠为研究模型，研究肺动脉高压大鼠肺血管炎症反应形成过程中内源性硫化氢体系的动态变化规律；通过激活或抑制内源性硫化氢体系，观察肺动脉高压大鼠肺血管炎症反应和肺动脉内皮细胞炎症因子合成和释放的改变，揭示内源性硫化氢对肺动脉高压形成中肺动脉内皮细胞炎症反应的调节作用；以核转录因子-κB (NF-κB) 信号通路为切入点，揭示硫化氢抑制肺动脉高压大鼠肺动脉内皮细胞炎症反应的信号转导通路；以NF-κB p65 cys38巯基基团为靶点，探索硫化氢抑制肺动脉内皮细胞NF-κB 信号通路的分子机制。通过上述研究，以期阐明内源性硫化氢对肺动脉高压大鼠肺血管炎症反应的调节作用及分子机制，进一步深化肺动脉高压的炎症机制理论，为探寻肺动脉高压的治疗靶点提供新思路。

既往研究表明内源性硫化氢是参与心血管调节的重要信号分子，内源性硫化氢体系下调是肺动脉高压发病的重要发病机制。在本项目中以肺血管炎症反应为切入点，以野百合碱（MCT）诱导肺动脉高压大鼠为模型，揭示硫化氢拮抗肺动脉高压及缓解肺血管重构的分子机制。研究发现，MCT诱导肺动脉高压大鼠内源性硫化氢体系显著下调，硫化氢供体可抑制MCT诱导肺血管炎症反应、肺动脉高压及肺血管重构，NF-κB通路介导硫化氢对MCT/野百合碱吡咯（MCTP）刺激肺动脉内皮细胞炎症反应的抑制效应。对其分子机制的研究发现，硫化氢抑制肺动脉内皮细胞NF-κB通路的靶点为上游调控分子IKKβ，硫化氢可对IKKβ的第179位半胱氨酸（Cys179）进行巯基化修饰，抑制IKKβ活性，进而抑制IKBα磷酸化及降解，抑制NF-κB p65磷酸化激活；在细胞及动物水平定点突变IKKβ Cys179，可阻断硫化氢对肺动脉内皮细胞炎症反应的抑制效应，进一步证实IKKβ Cys179是硫化氢发挥抗炎症效应的分子靶点。通过上述研究结果，本项目阐明了硫化氢抑制肺血管内皮炎症反应的分子机制及作用靶点。围绕上述研究，共发表SCI论文8篇；在国内外学术会议上特邀讲座8次，大会发言4次；培养博士研究生1人，硕士研究生2人。本研究结果为临床治疗肺动脉高压提供了全新的治疗靶点，为硫化氢作为药物研发提供了新的证据，并有望成为肺动脉高压临床防治的新的研究方向。