The Src-cortactin pathway is required for clustering of E-selectin and ICAM-1 in endothelial cells
The Src-cortactin pathway is required for clustering of E-selectin and ICAM-1 in endothelial cells
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DOI：
10.1096/fj.01-0969fje
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发表时间：
2002-06-01
期刊：
影响因子：
4.8
通讯作者：
Hoover, RL
中科院分区：
文献类型：
--
作者：
Tilghman, RW;Hoover, RL
在炎症部位的内皮细胞（EC）上表达的粘附分子如E-选择素和细胞间粘附分子-1（ICAM-1）在白细胞从血流募集到血管外组织中起重要作用。然而，很少有人知道的信号转导途径，开始在内皮细胞后粘附分子的参与。在这里，我们报告说，85 kDa的蛋白成为酪氨酸磷酸化的人内皮细胞白细胞粘附后或抗体诱导的E-选择素或ICAM-1的聚类。通过免疫沉淀实验，该蛋白被鉴定为corneumn，一种细胞粘附分子和参与细胞粘附的重要src底物。继粘附分子聚集后，src家族激酶抑制剂PP 2抑制了coronin磷酸化。src和酪氨酸磷酸化的皮质蛋白被发现与E-选择素和ICAM-1抗体包被的珠粘附到EC后。PP 2并不抑制coronin与E-selectin和ICAM-1的结合;然而，PP 2抑制多聚甲醛固定的THP-1细胞与EC之间的粘附。这种粘附力的降低与PP 2处理的内皮细胞上THP-1附着位点的粘附分子聚集的抑制有关。这些研究结果牵连src和corneum作为介导的白细胞/EC相互作用的炎症部位，通过调节粘附分子聚集在EC。
Adhesion molecules such as E-selectin and intercellular adhesion molecule-1 (ICAM-1) expressed on endothelial cells (ECs) at sites of inflammation play an important role in the recruitment of leukocytes from the bloodstream into extravascular tissue. However, little is known about the signaling pathways that are initiated in ECs following adhesion molecule engagement. Here, we report that an 85-kDa protein becomes tyrosine phosphorylated in human ECs following leukocyte adhesion or upon antibody-induced clustering of E-selectin or ICAM-1. Through immunoprecipitation experiments, this protein was identified as cortactin, a cytoskeleton-binding molecule and prominent src substrate involved in cell adhesion. Following adhesion molecule clustering, cortactin phosphorylation was inhibited by the src family kinase inhibitor PP2. Both src and tyrosine-phosphorylated cortactin were found to be associated with E-selectin and ICAM-1 following adhesion of antibody-coated beads to ECs. PP2 did not inhibit the association of cortactin with E-selectin and ICAM-1; however, PP2 inhibited adhesion between paraformaldehyde-fixed THP-1 cells and ECs. This decrease in adhesion correlated with inhibition of adhesion molecule clustering on PP2-treated ECs at sites of THP-1 attachment. These findings implicate src and cortactin as mediators of leukocyte/EC interactions at sites of inflammation by regulating adhesion molecule clustering on ECs.