干预肝细胞氧化应激感受器Keap1对肝星状细胞基质金属蛋白酶-2表达及其活性调节的影响  

Effects of hepatocytes with Keap1 knock- down on the expression and activity of matrix metalloproteinase- 2 in hepatic stellate cells

作　　者：蔡盈盈 陈平圣 CAI Yingying;CHEN Pingsheng(Department of Pathology and Pathophysiology,School of Medicine,Southeast University,Nanjing 210009,China)

机构地区：[1]东南大学医学院病理学与病理生理学系

出　　处：《东南大学学报（医学版）》2019年第6期947-953,共7页Journal of Southeast University(Medical Science Edition)

基　　金：国家自然科学基金面上项目资助课题(81370868)

摘　　要：目的:建立稳定敲低肝细胞内氧化应激感受器Kelch样ECH相关蛋白1(Kelch-like ECH-associated protein1,Keap1)的模型,探讨稳定下调Keap1的缺氧肝细胞对小鼠肝星状细胞(HSCs)基质金属蛋白酶-2(MMP-2)活性及其调控分子基质金属蛋白酶抑制因子-2(TIMP-2)、MMP-14、小窝蛋白-1(Cav-1)的影响。方法:根据本组建立的方法,构建Keap1下调的稳转肝细胞株,缺氧条件下培养Keap1下调的肝细胞,通过蛋白质印迹法和QPCR验证肝细胞中Keap1mRNA是否下调以及其下游分子和肿瘤坏死因子α(TNF-α)的表达水平。利用上述肝细胞培养上清液干预小鼠肝星状细胞株(HSC-T6),分别收集小鼠HSC-T6细胞培养上清液和细胞,通过蛋白质印迹法检测小鼠HSC-T6细胞的Keap1、抗氧化应激分子核因子E2相关因子2(Nrf2)、MMP-2等蛋白表达,明胶酶谱法检测小鼠HSC-T6细胞培养液上清中MMP-2活性。结果:稳定敲低肝细胞内氧化应激感受器Keap 1后,Nrf2表达增高,肿瘤坏死因-α(TNF-α)表达减少。与对照组相比,敲低Keap1的肝细胞培养液上清使小鼠HSC-T6细胞的MMP-2、Cav-1、MT1-MMP、TIMP-2蛋白表达减少而MMP-2的活性增高。结论:缺氧条件培养稳定敲低Keap1的肝细胞,肝细胞损伤程度减轻,合成及释放TNF-α减少。肝细胞培养上清液对HSC-T6细胞内吞相关分子Cav-1表达的刺激作用降低,减轻了Cav-1对膜表面的MMP-2活化的干扰,使MMP-2活性得以升高。Objective:To establish an interventional model of knockdown Kelch-like ECH-associated protein 1(Keap1)in hepatocytes and investigate the influence of hypoxic hepatocytes with Keap1 knock-down on the matrix metalloproteinase-2(MMP-2),and the corresponding regulatory molecules such as matrix metalloproteinase inhibitor(TIMP-2),membrane-type 1 matrix metalloproteinase(MT1-MMP or MMP14),caveolin-1(Cav-1)of the hepatic satellite cells(HSCs).Methods:According to the method established by our group,the hepatocytes with Keap1 knock-down was constructed,and were cultured under hypoxic conditions.The expression levels of Keap1 and nuclear factor erythroid 2 related factor 2(Nrf2),tumor necrosis factor-α(TNF-α)its downstream molecules of the hepatocytes were measured by Western blotting and QPCR.Hepatic stellate cells(HSC-T6)were cultured in the above-mentioned hepatocyte culture supernatant,then HSC-T6 cells and culture supernatant were collected.Expression of Keap1,Nrf2 and MMP-2 of the HSC-T6 cells were detected by Western blotting,the activity of MMP-2 in supernatant of HSC-T6 cells was measured by gelatin zymography.Results:After stable knock-down of Keap1,the expression of Nrf2 was increased and the expression of TNF-αwas decreased in the hepatocytes.Compared with the control group,the culture supernatant of hepatocytes with Keap1 knock-down reduced the expression of MMP-2,Cav-1,MT1-MMP,TIMP-2 protein and increased the activity of MMP-2 in HSC-T6 cells.Conclusion:When hepatocytes with Keap1 knock-down are under hypoxic conditions,the degree of hepatocyte injury is reduced,and the synthesis and release of TNF-αare decreased,which may reduce the stimulation of Cav-1 in endocytic molecules of HSC-T6 cells.Cav-1 interferes with MMP-2 activation on the membrane surface,in this condition the MMP-2 activity is increased.

关 键 词：Kelch样ECH相关蛋白1 基质金属蛋白酶-2 缺氧 

分 类 号：R362[医药卫生—病理学]