氢气对重度脓毒症肠屏障功能障碍的影响及分子机制

Intestinal barrier dysfunction is the motor of MODS induced by severe sepsis. Our previous studies show that hydrogen could remarkably improve the survival rate and organ function of septic mice, also alleviate intestinal pathological damage. But the mechanism is still unclear. Recently, the Rho signal pathway has an important role in regulating intestinal barrier function, such as the intracellular junctions. We found that hydrogen could reduce the intestinal RhoA expression，suggesting that Rho-ROCK/mDia pathway plays an important role in the protective effects of hydrogen against intestinal barrier dysfunction. From molecular, cellular to animal levels, using technologies such as LSCM(laser scanning confocal microscope), ELISA, PCR,IHC and Western-blot，this study was designed to observe the alteration in ultramicro structures such as the tight and adherent junctions in enteric epithelium, the permeability of intestinal mucosa, the bactieral translocation and the expression of inflammatory factors before and after hydrogen treatment. In addition, we examine the expression changes of RhoA/ROCK and mDia,also downstream substrate of myosin light chain phosphorylation before and after hydrogen treatment. We also give pharmocalogical intervention and RNAi to affect the expressions of RhoA/ROCK and mDia, and to discover the detailed mechanisms of Rho/ROCK and mDia signal pathway in the hydrogen treatment of intestinal barrier dysfunction in septic mice, which could provide new targets for treatment of sepsis.

肠屏障功能障碍是重度脓毒症时多器官衰竭的"Motor"。本课题组前期发现氢气显著改善脓毒症小鼠生存率和器官功能，也减轻肠组织病理损伤。Rho信号通路在调控细胞间紧密连接中起关键作用，参与脓毒症肠屏障功能障碍的调节。我们预实验发现氢气明显降低肠组织中RhoA表达，表明：Rho-ROCK/mDia通路参与氢气保护脓毒症肠屏障功能障碍的过程。本项目拟从细胞和动物水平，利用透射电镜、激光共聚焦显微镜、ELISA、PCR、IHC、Western-blot等技术观察氢气对重度脓毒症小鼠肠上皮细胞和细胞间超微结构的改变，肠上皮细胞间连接蛋白的异常分布与表达，及肠粘膜通透性、细菌移位和炎症因子水平等影响；同时检测RhoA及下游ROCK和mDia的表达情况，及对下游底物肌球蛋白轻链磷酸化的影响；此外利用相关干预剂，明确Rho-ROCK/mDia通路在氢气治疗脓毒症肠屏障功能障碍中的具体机制。

肠屏障功能障碍是重度脓毒症时多器官衰竭的"Motor"。本课题组前期发现氢气显著改善脓毒症小鼠生存率和器官功能，也减轻肠组织病理损伤。Rho信号通路在调控细胞间紧密连接中起关键作用，参与脓毒症肠屏障功能障碍的调节。我们预实验发现氢气明显降低肠组织中RhoA表达，表明：Rho-ROCK/mDia通路参与氢气保护脓毒症肠屏障功能障碍的过程。本项目拟从细胞和动物水平，利用透射电镜、激光共聚焦显微镜、ELISA、PCR、IHC、Western-blot等技术观察氢气对重度脓毒症小鼠肠上皮细胞和细胞间超微结构的改变，肠上皮细胞间连接蛋白的异常分布与表达，及肠粘膜通透性、细菌移位和炎症因子水平等影响；同时检测RhoA及下游ROCK和mDia的表达情况，及对下游底物肌球蛋白轻链磷酸化的影响；此外利用相关干预剂，明确Rho-ROCK/mDia通路在氢气治疗脓毒症肠屏障功能障碍中的具体机制。