内源性二氧化硫对低氧性肺血管结构重构形成中肺血管炎症反应的调节作用及分子机制

Pulmonary vascular inflammation is an important process in the development of hypoxic pulmonary vascular structural remodeling. However, the mechanisms responsible for pulmonary vascular inflammation induced by hypoxia have been unclear. The applicant’s previous studies demonstrated that endogenous sulfur dioxide (SO2) inhibited pulmonary vascular structural remodeling. The present study is, therefore, designed to investigate the dynamic changes in endogenous SO2/aspartate aminotransferanse (AAT) pathway and pulmonary vascular inflammatory response in rats with hypoxic pulmonary vascular structural remodeling. By activating and inhibiting the endogenous SO2 pathway in the vascular endothelium specific AAT transgenic or knockout mice, the study is designed to elucidate the effect of activation or inhibition of endogenous SO2 production on hypoxic pulmonary vascular inflammatory response. Furthermore, the role of NF-κB pathway in the inhibition of hypoxic pulmonary vascular inflammatory response by sulfur dioxide is to be determined by inhibiting NF-κB pathway in hypoxic primary human pulmonary artery endothelial cell or in vascular endothelium specific AAT knockout mice. By using sulfhydryl specific and sulfhydryl oxidation specific probes, mass spectrometry analysis and site-directed mutation technology, sulfhydryl oxidation of NF-κB p65 and its localization is to be examined. The above studies would deepen the understanding of the role of SO2 in pulmonary vascular inflammatory response, its signaling pathway, molecular mechanisms and the regulatory theory of hypoxic pulmonary structural remodeling and provide new research strategy for discovering therapeutic target of pulmonary hypertension.

肺血管炎症反应是低氧性肺血管结构重构形成的重要环节，但低氧刺激肺血管炎症发生的分子机制尚不清楚。本课题组前期研究发现二氧化硫(SO2)抑制低氧性肺血管结构重构。因此，本课题将进一步探索低氧性肺血管结构重构中内源性SO2/AAT体系与肺血管炎症反应的动态变化；在血管内皮特异性AAT转基因及敲除小鼠中，研究激活或抑制内源性SO2生成对低氧性肺血管炎症反应的影响；通过抑制原代肺动脉内皮细胞NF-κB通路及小鼠血管内皮细胞特异性p65基因敲除，揭示NF-κB通路在SO2抑制低氧性肺血管炎症反应中的作用；通过特异性巯基及巯基氧化修饰探针、质谱分析和点突变技术，阐明SO2对p65蛋白cys38巯基的氧化修饰作用。通过上述研究，以期揭示SO2 对低氧性肺血管结构重构形成中肺血管炎症反应的调节作用、信号通路及分子机制，深化低氧性肺血管结构重构的炎症调节理论，并为寻找肺动脉高压治疗的炎症干预靶点提供新思路。

低氧性肺血管炎症反应是肺动脉高压及肺血管重构的重要启动环节，阐明其发病机制是早期干预低氧性肺血管重构的关键科学问题，但是迄今为止肺血管炎症的发生机制并未完全阐明。本项目在既往创新性发现内源性二氧化硫是心血管调节的新的气体信号分子研究基础上，探索内源性二氧化硫在低氧性肺血管炎症反应发生中的调节作用及机制。研究发现，低氧抑制肺组织内源性二氧化硫生成，形成显著肺血管炎症反应及肺血管重构；二氧化硫供体可抑制低氧大鼠肺血管炎症反应，缓解肺血管重构；血管内皮细胞及血管平滑肌细胞特异性AAT1过表达均可阻断低氧刺激小鼠肺血管炎症反应，缓解肺血管重构；揭示二氧化硫通过次磺化修饰抑制NF-κB p65活性，首次证实二氧化硫对蛋白质的翻译后修饰作用; 阐明血管内皮细胞中二氧化硫与硫化氢的相互作用参与血管炎症反应的稳态调节；首次揭示管周脂肪来源的二氧化硫是血管炎症抑制因子。围绕上述研究，共发表SCI论文9篇，在国内外学术会议特邀讲座2次，大会发言3次，培养博士研究生2人，硕士研究生2人。通过上述系列研究，阐明了内源性二氧化硫是拮抗低氧引发血管炎症反应进而启动肺血管损伤及重构病变的重要防御体系，内源性二氧化硫生成不足是低氧性肺血管炎症发生的重要发病机制。从气体信号分子二氧化硫调控角度切入，深化低氧性肺血管结构重构形成中肺血管炎症反应的调节机制，为寻找肺动脉高压治疗的炎症干预靶点提供新思路。