晚期糖基化终产物诱导内皮细胞黏附连接改变及其机制

目的观察不同浓度和时间修饰的糖基化人血清白蛋白作用下,人脐静脉内皮细胞内黏附连接蛋白钙黏着蛋白的形态结构变化,并初步探讨其机制。方法原代培养人脐静脉内皮细胞,分别用不同浓度和时间修饰的糖基化人血清白蛋白处理,用免疫荧光染色法、激光共聚焦显微镜观察钙黏着蛋白在内皮细胞的形态和分布变化。分别用可溶性的修饰的糖基化人血清白蛋白受体的抗体、丝裂原活化蛋白激酶抑制剂或转染重组腺病毒突变体转染预处理后再观察晚期糖基化终产物修饰的人血清白蛋白对内皮细胞形态的影响。结果修饰的糖基化人血清白蛋白以时间和剂量依赖方式引起内皮细胞黏附连接钙黏着蛋白形态结构的改变;丝裂原活化蛋白激酶通路抑制剂(SB203580、PD98059、SP600125)和Rho激酶抑制剂Y27632均可减轻晚期糖基化终产物对钙黏蛋白的影响;转染显性失活的细胞外信号调节激酶上游激酶MEK1和p38丝裂原活化蛋白激酶上游激酶MKK6b及p38显性失活的p38α和p38β重组腺病毒突变体,均可减轻晚期糖基化终产物对钙黏蛋白形态结构的影响,而转染组成性激活的MEK1和MKK6b的重组腺病毒本身即可引起钙黏蛋白形态结构的变化。结论晚期糖基化终产物刺激可以引起钙黏蛋白分布和形态的变化,这一作用可能是丝裂原活化蛋白激酶通路细胞外信号调节激酶、p38丝裂原活化蛋白激酶信号通路和c-jun氨基末端激酶(JNK)/应激激活的蛋白激酶(SAPK)介导的,Rho激酶可能参与此过程。

The Morphological Changes of Vascular Endothelial Cadherin in Human Umbilical Vein Endothelial Cells Induced by Advanced Glycation End Products

Aim To determine whether advanced glycation end products(AGE)altered the morphology and distribution of the adherens junction protein vascular endothelial(VE)-cadherin in human umbilical vein endothelial cells(hUVEC)and to understand the mechanism of this alteration.Methods Human umbilical vein endothelial cells(hUVEC)were respectively incubated with AGE-HSA in different concentrations and timing.In some other cases,hUVECs were pretreated with mitogen activated protein kinase(MAPK)pathway inhibitors(PD98059,SP600125,SB203580),or transfected with adenovirus.To visualize the morphological changes of VE-cadherin,cells were incubated with rabbit anti-VE-cadherin primary antibody and then FITC anti-rabbit IgG secondary antibody.The morphological changes of VE-cadherin were observed with confocal microscope.Results The morphological of VE-cadherin was significantly changed in coincident with an increase of the dose and time of AGE-HSA.These changes could be inhibited with MAPK and Rho inhibitors.Conclusion These observations suggested that AGE modified proteins can induce morphological changes of VE-cadherin in endothelial cell.Activations of MAP kinase and Rho kinase pathways play an important role in AGEs-induced hUVECs VE-cadherin distribution.