基于GRP78介导的内质网应激调控PI3K/PTEN/Akt/NF-κb信号通路探讨EGCG对哮喘气道黏液高分泌的作用机制

Airway mucus hypersecretion is a commom pathological change in the chronic airway disease，which is closely associated with airway inflammation and airway remodeling in asthma. In the precious study, We had found that EGCG treatment could alleviate airway inflammation ,reduce the secretion of airway mucus, and inhibit the activation of PI3K/PTEN/Akt signal pathway in asthmatic mice. It is still unclear that whether PI3K/PTEN/Akt signal pathway involved in the mechanism of EGCG on the secretion of airway mucus and how to regulate this process. This project will discuss that whether the EGCG regulate PI3K/PTEN/Akt/NF-kappa B signal pathway through endoplasmic reticulum stress mediated by GRP78s, play a vital role of reducing airway mucus secretion in asthma through animal experiments and cytological examination, application of PCR, protein imprinting, cell transfection and other molecular biology technology. Trying to confirm: endoplasmic reticulum stress mediated by GRP78 involved in the airway inflammation and airway mucus hypersecretion in asthma;EGCG inhibit the activation of unfolded protein response through down-regulating the expression of GRP78; EGCG inhibit the activation of PI3K/PTEN/Akt/NF-κB sianal pathway by up-regulating the expression of PTEN; involve in the process of secretion of airway mucus.This study will provide the theoretical and experimental basis for EGCG used for asthma treatment.

气道黏液高分泌,是慢性气道疾病的常见病理表现，与哮喘气道炎症和气道重塑的发生、发展密切相关。申请者发现EGCG治疗可减轻哮喘小鼠气道炎症，减少气道黏液分泌，同时可抑制PI3K/PTEN/Akt信号通路活化。而对于EGCG减轻气道黏液分泌的机制是否与PI3K/PTEN/Akt信号通路有关，又通过何种途径进行调控，尚不清楚。本项目将通过动物实验和细胞学检测，应用PCR、蛋白印迹、细胞内转染等多种分子生物学技术，探讨EGCG是否通过GRP78介导的内质网应激调控PI3K/PTEN/Akt/NF-κB信号通路，起到减轻哮喘气道黏膜高分泌的作用。试图证实：GRP78介导的内质网应激参与哮喘气道炎症及气道黏液高分泌，EGCG通过下调GRP78表达，抑制蛋白质非折叠蛋白反应活化，进而上调PTEN表达，抑制PI3K/PTEN/Akt/NF-κB通路活化，发挥减轻气道黏液分泌的作用。

气道黏液高分泌,是慢性气道疾病的常见病理表现，与哮喘气道炎症和气道重塑的发生、 发展密切相关。申请者前期研究发现EGCG治疗可抑制PI3K/ PTEN/ Akt信号通路活化从而发挥减轻哮喘小鼠气道炎症的作用。近年来文献报道哮喘气道炎症反应可诱导内质网应激，活化蛋白质非折叠反应（UPR），此过程参与了哮喘气道上皮细胞凋亡、气道上皮下的纤维化形成及气道黏液分泌等气道重塑过程，而对于EGCG减轻气道炎症和黏液高分泌的机制是否与气道上皮细胞内质网应激有关，又通过何种途径进行调控，尚不清楚。本研究通过动物实验和细胞学检测，应用PCR、蛋白印迹、免疫荧光、细胞转染等多种分子生物学技术，证实GRP78介导的内质网应激参与哮喘气道炎症及气道黏液高分泌；EGCG通过下调GRP78表达，抑制蛋白质非折叠蛋白反应活化，进而上调PTEN表达，抑制PI3K/PTEN/Akt/NF-κB通路活化，发挥减轻气道黏液分泌的作用。该研究结果进一步证实内质网应激参与了哮喘小鼠气道黏液高分泌的调控，EGCG可能通过抑制内质网应激减轻气道黏液高分泌，为EGCG用于哮喘治疗提供新的理论依据。