Role of p120 in mechanical stretch-induced transferring of E-cadherin to cytoplasm in mouse alveolar epithelial cells / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of pl20-catenin protein (p120) in mechanical stretchinduced transferring of E-cadherin to cytoplasm in mouse alveolar epithelial cells.Methods Experiment Ⅰ Mouse alveolar epithelial cells (MLE-12 cells) were seeded in 6-well cell stretch plates at a density of (1.0-1.5) ×106 cells/well and divided into 3 groups (n=12 each) using a random number tablecontrol group (group C),cyclic stretch for 2 h group (group CS2) and cyclic stretch for 4 h group (group CS4).The cells underwent 20％ cyclic stretch at 0.5 Hz (stretchintermittence =1 ∶ 1) for 2 and 4 h in CS2 and CS4 groups,respectively.The cells underwent no cyclic stretch in group C.The expression of p120,E-cadherin and phosphorylated Src kinase (p-Src) and expression of E-cadherin in cytomembrane and cytoplasma were detected by Western blot.Experiment Ⅱ MLE-12 cells were seeded in 6-well cell stretch plates at a density of (1.0-1.5)× 106 cells/well and divided into 4 groups (n =6 each) using a random number tablecontrol group (group C),cyclic stretch group (group CS),p120 small interfering RNA (siRNA) transfection group (group p120 siRNA),and p120 siRNA transfection plus cyclic stretch group (group p120 siRNA+CS).The cells were transfected with scramble siRNA in C and CS groups,and 24 h later the cells underwent 20％ cyclic stretch for 2 h at 0.5 Hz (stretchintermittence =1 ∶ 1) in group CS.The cells were transfected with p120 siRNA in p120 siRNA and p120 siRNA+CS groups,and 24 h later the cells underwent 20％ cyclic stretch for 2 h at 0.5 Hz (stretch ∶ intermittence =1 ∶ 1) in group p120 siRNA+CS.The expression of E-cadherin in cytomembrane and cytoplasm was detected by Western blot after the end of treatment in each group.Results Experiment Ⅰ Compared with group C,the expression of p120 and E-cadherin was significantly down-regulated,the expression of p-Src was up-regulated,the expression of E-cadherin in cytomembrane was down-regulated,and the expression of E-cadherin in cytoplasm was up-regulated in CS2 and CS4 groups (P ＜ 0.05).Compared with group CS2,the expression of p120 and E-cadherin was significantly down-regulated,the expression of p-Src was up-regulated,the expression of E-cadherin in cytomembrane was down-regulated,and the expression of E-cadherin in cytoplasm was upregulated in group CS4 (P ＜ O.05).Experiment Ⅱ Compared with group C,the expression of E-cadherin in cytomembrane was significantly down-regulated,and the expression of E-cadherin in cytoplasm was up-regulated in CS,p120 siRNA and p120 siRNA+CS groups (P＜ 0.05).Compared with group CS or group p120 siRNA,the expression of E-cadherin in cytomembrane was significantly down-regulated,and the expression of E-cadherin in cytoplasm was up-regulated in group p120 siRNA+CS (P＜0.05).Conclusion The degradation of p120 can promote mechanical stretch-induced transferring of E-cadherin to cytoplasm in mouse alveolar epithelial cells.