Tumor necrosis factor-α induces early-onset endothelial adhesivity by protein kinase Cζ-dependent activation of intercellular adhesion molecule-1
Tumor necrosis factor-α induces early-onset endothelial adhesivity by protein kinase Cζ-dependent activation of intercellular adhesion molecule-1
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DOI：
10.1161/01.res.0000072971.88704.cb
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发表时间：
2003-05-30
影响因子：
20.1
通讯作者：
Malik, AB
中科院分区：
文献类型：
--
作者：
Javaid, K;Rahman, A;Malik, AB
我们测试了这样的假设：TNF-alpha通过激活组成性内皮细胞表面ICAM-1（β 2-整联蛋白（CD 11/CD 18）反受体）诱导对中性粒细胞的早发性内皮粘附性。用TNF-α刺激人肺动脉内皮细胞导致ICAM-1在1分钟内磷酸化，这种反应在TNF-α刺激后持续长达15分钟。我们观察到TNF-α以ICAM-1依赖的方式诱导PMN与内皮细胞的粘附增加10倍，并且这种反应抑制了ICAM-1磷酸化的快速时间过程。我们还观察到，早发性TNF-α诱导的内皮细胞粘附性与蛋白质合成无关，并与细胞表面ICAM-1聚集有关。用泛蛋白激酶C抑制剂白屈菜红碱预处理细胞，阻止了内皮粘附性的激活。由于PKCzeta是一种在内皮细胞中大量表达的非典型PKC亚型，参与了TNF-α诱导的ICAM-1基因转录的信号传导，我们确定了PKCzeta通过ICAM-1表达参与介导内皮粘附性的可能性。我们观察到，TNF-α刺激内皮细胞诱导PKCzeta激活及其与ICAM-1的关联。通过药理学和遗传学方法抑制PKCzeta防止了TNF-α诱导的磷酸化和细胞表面ICAM-1的聚集以及内皮粘附性的激活。因此，TNF-α通过细胞表面ICAM-1的PKC ζ依赖性磷酸化（先于ICAM-1的从头合成）诱导内皮粘附性的早发性、蛋白质合成非依赖性表达。ICAM-1的快速表达是促进PMN与内皮细胞稳定粘附的一种新机制，这种粘附是促进PMN早期跨内皮迁移所必需的。
We tested the hypothesis that TNF-alpha induces early-onset endothelial adhesivity toward PMN by activating the constitutive endothelial cell surface ICAM-1, the beta(2)-integrin (CD11/CD18) counter-receptor. Stimulation of human pulmonary artery endothelial cells with TNF-alpha resulted in phosphorylation of ICAM-1 within 1 minute, a response that was sustained up to 15 minutes after TNF-alpha challenge. We observed that TNF-alpha induced 10-fold increase in PMN adhesion to endothelial cells in an ICAM-1-dependent manner and that this response paralleled the rapid time course of ICAM-1 phosphorylation. We also observed that the early-onset TNF-alpha-induced endothelial adhesivity was protein synthesis-independent and associated with cell surface ICAM-1 clustering. Pretreatment of cells with the pan-PKC inhibitor, chelerythrine, prevented the activation of endothelial adhesivity. As PKCzeta, an atypical PKC isoform abundantly expressed in endothelial cells, is implicated in signaling TNF- alpha-induced ICAM-1 gene transcription, we determined the possibility that PKCzeta was involved in mediating endothelial adhesivity through ICAM-1 expression. We observed that TNF-alpha stimulation of endothelial cells induced PKCzeta activation and its association with ICAM-1. Inhibition of PKCzeta by pharmacological and genetic approaches prevented the TNF-alpha-induced phosphorylation and the clustering of the cell surface ICAM-1 as well as activation of endothelial adhesivity. Thus, TNF-alpha induces early-onset, protein synthesis-independent expression of endothelial adhesivity by PKCzeta-dependent phosphorylation of cell surface ICAM-1 that precedes the de novo ICAM-1 synthesis. The rapid ICAM-1 expression represents a novel mechanism for promoting the stable adhesion of PMN to endothelial cells that is needed to facilitate the early-onset transendothelial migration of PMN.