Oxidized phospholipids mediate occludin expression and phosphorylation in vascular endothelial cells
Oxidized phospholipids mediate occludin expression and phosphorylation in vascular endothelial cells
复制标题
DOI：
10.1152/ajpheart.00554.2005
复制
发表时间：
2006-02-01
影响因子：
4.8
通讯作者：
Hsiai, TK
中科院分区：
文献类型：
--
作者：
DeMaio, L;Rouhanizadeh, M;Hsiai, TK
氧化的L-α-1-棕榈酰-2-花生四烯酰-sn-甘油-3-磷酸胆碱（OxPAPC）是最低限度修饰的LDL的一种成分，可诱导促炎细胞因子的产生和动脉粥样硬化病变的发展。我们测试的假设，OxPAPC改变紧密连接（TJ）蛋白，特别是occludin，跨膜TJ蛋白的表达，磷酸化和本地化。在牛主动脉内皮细胞中，OxPAPC剂量依赖性（10 - 50 μ g/ml）和时间依赖性地减少总闭合蛋白蛋白和增加闭合蛋白磷酸化。OxPAPC降低occludin mRNA的表达，并降低细胞-细胞接触处的闭锁小带-1的免疫反应性。此外，OxPAPC以剂量依赖性方式增加10 kDa右旋糖酐的扩散通量。O-2（-.）暴露于OxPAPC后，牛主动脉内皮细胞的产量增加了近两倍。此外，酶促产生O-2（-.）通过黄嘌呤氧化酶-鲁马嗪和H2 O2通过葡萄糖氧化酶-葡萄糖增加occludin磷酸化，暗示活性氧物种作为OxPAPC对occludin磷酸化作用的调节剂。超氧化物歧化酶和/或过氧化氢酶阻断OxPAPC对闭合蛋白蛋白含量和磷酸化、闭合蛋白mRNA、闭合小带-1免疫反应性和10-kDa葡聚糖扩散通量的影响。这些发现表明，TJ蛋白的变化是OxPAPC损害血管内皮屏障特性的潜在机制。OxPAPC诱导的TJ破坏可能促进LDL和炎性细胞迁移到内皮下层，可能由活性氧介导。
Oxidized L-alpha-1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine ( OxPAPC), a component of minimally modified LDL, induces production of proinflammatory cytokines and development of atherosclerotic lesions. We tested the hypothesis that OxPAPC alters expression, phosphorylation, and localization of tight junction ( TJ) proteins, particularly occludin, a transmembrane TJ protein. OxPAPC reduced total occludin protein and increased occludin phosphorylation dose dependently ( 10 - 50 mu g/ml) and time dependently in bovine aortic endothelial cells. OxPAPC decreased occludin mRNA and reduced the immunoreactivity of zonula occludens-1 at the cell-cell contacts. Furthermore, OxPAPC increased the diffusive flux of 10kDa dextran in a dose-dependent manner. O-2(-.) production by bovine aortic endothelial cells increased nearly twofold after exposure to OxPAPC. Also, enzymatic generation of O-2(-.) by xanthine oxidase-lumazine and H2O2 by glucose oxidase-glucose increased occludin phosphorylation, implicating reactive oxygen species as modulators of the OxPAPC effects on occludin phosphorylation. Superoxide dismutase and/or catalase blocked the effects of OxPAPC on occludin protein content and phosphorylation, occludin mRNA, zonula occludens-1 immunoreactivity, and diffusive flux of 10-kDa dextran. These findings suggest that changes in TJ proteins are potential mechanisms by which OxPAPC compromises the barrier properties of the vascular endothelium. OxPAPC-induced disruption of TJs, which likely facilitates transmigration of LDL and inflammatory cells into the subendothelial layers, may be mediated by reactive oxygen species.