阿司匹林对人胃黏膜上皮细胞生长和occludin蛋白表达的影响及其机制研究

摘要

It was reported that activation of ERK signal pathway could promote cell growth and up-regulate the expression of tight junction protein occludin, while aspirin could inhibit the phosphorylated activation of ERK. Aims: To study the effect and possible mechanism of aspirin on cell growth and occludin expression in human gastric mucosal epithelial cells. Methods: Human gastric mucosal epithelial cell line GES-1 was cultured in vitro to form monolayer cells and treated with aspirin (5-20 mmol/L) and MEK inhibitor U0126 (10-40 μmol/L), respectively. Cell growth inhibition was measured by MTT assay. Then the GES-1 cells were divided into four groups and incubated with 8.78 mmol/L aspirin, 14.91 μmol/L U0126, U0126 plus aspirin, or cultured as control, respectively. Morphological changes of GES-1 cells were observed under inverted phase contrast microscope, cell apoptosis was assessed by flow cytometry, and expressions of p-ERK1/2 and occludin proteins were determined by Western blotting. Results: Both aspirin and U0126 inhibited the growth of GES-1 cells in a dose-dependent manner. Cell apoptosis, as well as the number of adherent cells were decreased more significantly in U0126 plus aspirin group, and cells became round and suspended. Both aspirin and U0126 could reduce the expressions of p-ERKl/2 and occludin proteins; U0126 and U0126 plus aspirin were more effective. Conclusions: Aspirin can inhibit the growth of human gastric mucosal epithelial cells and down-regulate occludin expression. The mechanism is at least partially related to the inhibition of ERK signal pathway activation.%背景:研究显示ERK信号通路激活可促进细胞生长,上调紧密连接蛋白occludin表达,而阿司匹林可抑制ERK的磷酸化激活.目的:探讨阿司匹林对人胃黏膜上皮细胞生长和occludin蛋白表达的影响及其可能机制.方法:建立人胃黏膜上皮细胞株GES-1单层细胞模型,MTT法检测阿司匹林(5～20 mmol/L)和MEK抑制剂U0126(10～40 μmol/L)对GES-1细胞的生长抑制作用.将GES-1细胞分为阿司匹林(8.78 mmol/L)组、U0126(14.91 μmol/L)组、联合组(U0126+阿司匹林)和阴性对照组,倒置相差显微镜下观察细胞形态学变化,流式细胞术检测细胞凋亡情况,蛋白质印迹法检测p=ERK1/2、occludin蛋白表达.结果:阿司匹林和U0126均能剂量依赖性地抑制GES-1细胞生长,联合组细胞凋亡较两药单用更为显著,贴壁细胞数量减少更为明显,细胞变圆、悬浮.阿司匹林组、U0126组和联合组pERK1/2、occludin蛋白表达量均显著低于阴性对照组,U0126组和联合组降低更为明显.结论:阿司匹林可抑制人胃黏膜上皮细胞生长,下调occludin蛋白表达,其机制至少部分与抑制ERK信号通路激活有关.