p120在机械通气诱发肺损伤过程中作用机制

A key factor in inducing lung edema and injury is the increase in alveolar membrane permeability. However, the function of cell adherent junctions in the mechanical induced VILI is still uncertain. As we previously described from isolated MLE12 cells after cycled stretch, down-regulation of p120 could lead to the openness of cell junction, along with the activation of c-src and decreased E-cadherin protein expression. To explore the function of this mechanism in the regulation of mechanical ventilation induced lung injure in live animals, we hypothesized that mechanical stretch can cause the degradation of p120 and occludin through activation of c-src, thus leading to decreased endocytosis of E-cadherin and weaken AJs. Meanwhile, down-regulated p120 resulted in activation of RhoA, degradation of occludin, JAM and disaggregation of occludin-ZO-1 complex, these consequential changes disrupt cell tight junction, finally leading to openness of cell junction and lung edema in live animals by using the technical of SiRNA/cDNA-p120、SiRNA/cDNA-JAM、KO-Ecad cells、 VILI model in mice and the methods of WB、IP、 confocal. In conclusion, we identified the mechanism of cell junction protein changes under mechanical stretch in vitro and vivo. Moreover, we elucidated the influence of mechanical stretch in inducing VILI, and thus provide new thoughts into the prevention and treatment of VILI.

细胞连接蛋白对维持肺泡膜通透性极为重要,但对机械通气诱发肺损伤（VILI）、肺水肿的作用目前未明。我们对MLE12细胞牵张发现：p120表达降低可致细胞间隙（gap）增加和c-src激活、E钙粘附蛋白（Ecad）减少。为探讨此机制及在活体VILI中作用，我们假设：机械力激活c-src降解p120、occludin；而p120的降低致Ecad胞内吞，减少细胞间粘附连接；同时p120降低激活RhoA降解occludin、JAM，解离occludin-ZO-1，影响细胞间致密连接，终致gap增加；在活体p120降低可致肺损伤加重。采用离体细胞SiRNA/cDNA-p120/JAM、KO-Ecad、活体小鼠VILI模型，使用WB、免疫荧光双标、IP/confocal等技术，明确细胞连接蛋白在机械力作用下改变机制和对VILI的影响，从细胞连接蛋白角度，为临床上VILI的防治提供新思路。

细胞连接蛋白对维持肺泡膜通透性极为重要,但对机械通气诱发肺损伤（VILI）、肺水肿的作用目前未明。我们对MLE12 细胞牵张发现：p120 表达降低可致细胞间隙（gap）增加和c-src 激活、E 钙粘附蛋白（Ecad）减少。为探讨此机制及在活体VILI 中作用，我们假设：机械力激活c-src 降解p120、occludin；而p120 的降低致Ecad 胞内吞，减少细胞间粘附连接；同时p120 降低激活RhoA 降解occludin、JAM，解离occludin-ZO-1，影响细胞间致密连接，终致gap 增加；在活体p120 降低可致肺损伤加重。采用离体细胞SiRNA/cDNA-p120/JAM、KO-Ecad、活体小鼠VILI 模型，使用WB、免疫荧光双标、IP/confocal等技术，明确细胞连接蛋白在机械力作用下改变机制和对VILI 的影响，从细胞连接蛋白角度，为临床上VILI 的防治提供新思路。