TRPC在肉鸡肺动脉高压综合征发病机制中的作用

Previous studies showed that a variety of cytokines are involved in the broiler pulmonary hypertension syndrome (PHS). However, it is not clear in the relationships between each factor signaling pathway. Pulmonary vasoconstriction increasing and pulmonary vascular remodeling（PVR）are important pathological features of broiler PHS. Transient receptor potential channel (TRPC) produced activation of the internal flow of calcium ions and related to vascular remodeling and vasoconstriction, which may be important signal transduction pathways of a variety of cytokines mediated broilers PHS. Unfortunately, no related researches are reported. The project is disigned to investigate the possible role of TRPC in broiler PHS. The main contents are as follows:1) the characteristics of TRPC gene and TRPC protein expression; 2) Effect of TRPC on the regulation of pulmonary artery contraction; 3) Effect of TRPC on the internal Ca2+ content of pulmonary arterial smooth muscle cell (PASMC); 4) Effect of TRPC on the proliferation of PASMC and its mechanism . Different from the former ideas of research on broiler PHS, the project is to elucidate the mechanism of pulmonary vasoconstriction increasing and PVR on broiler PHS, from the perspective of TRPC regulation on pulmonary vasoconstriction and PASMC proliferation, which will provide theoretical knowledge for the treatment of pulmonary arterial hypertension through the TRPC channel specific blocking agents.

前人和本课题组前期研究发现，多种细胞因子参与了肉鸡肺动脉高压综合征（PHS）发生，但各因子作用信号途径及之间关联尚不明确。瞬时受体电位离子通道（TRPC）作为胞膜上的重要的Ca2+通道，在调节血管紧张度和细胞增殖、血管重构等方面起到重要作用，可能是多种细胞因子变化介导肉鸡PHS发生的重要信号转导途径。本项目拟以肉鸡活体和肺动脉平滑肌细胞（PASMC）为材料，研究 TRPC在PHS发生中的调控作用。主要内容包括：1）TRPC 基因及蛋白表达特性；2）TRPC对细胞内钙离子浓度的调节作用；3）TRPC对肺动脉收缩反应的调节作用；4）TRPC 对PASMC 增殖的调节作用及机制。不同于以往研究思路，本项目从 TRPC对肺血管收缩和PASMC增殖的调控角度，阐明PHS肉鸡肺血管收缩增强和肺血管重构病理特征的发生机制，为TRPC特异性阻断剂防控PHS提供理论基础。

肉鸡肺动脉高压（PHS）又被称作肉鸡腹水综合征（AS），主要危害快速生长的肉鸡。肺血管收缩反应增强和肺血管重构是肉鸡PHS发生的两个重要病理特征。TRPC 是构成细胞膜上受体操作性和钙池操作性钙离子通道的分子基础，是钙离子内流的主要通道，与细胞转录因子的活化、细胞程序性死亡以及细胞增殖密切相关。本项目以肉鸡活体和肺动脉平滑肌细胞（PASMCs）为对象，研究TRPC在肉鸡肺动脉高压（PHS）病理发生中的作用，重要研究成果有：1）成功建立了肉鸡PHS模型和PASMCs体外培养的低氧模型；2）通过RT-PCR、免疫组化以及WB评价了TRPC各亚型在PHS肉鸡肺和心肌组织中的表达情况；3）同时在PASMCs体外培养的低氧模型，评价了TRPC在PASMCs中的表达情况，以及TRPC的表达与细胞内游离钙离子的浓度之间的关系；4）使用TRPC6的激活剂和阻断剂处理缺氧条件下培养的PASMCs，评价细胞内游离钙离子浓度、TRPC6的表达、细胞凋亡及细胞周期的变化，阐明TRPC6对PASMCs内钙的调节作用。本项目从体内和体外两部分实验明确了TRPC通过调控细胞内游离钙离子浓度，从而影响PASMCs增殖和凋亡，阐明了肉鸡PHS病理发生机制。