VCAM-1 signals activate endothelial cell protein kinase Calpha via oxidation.
VCAM-1 signals activate endothelial cell protein kinase Calpha via oxidation.
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发表时间：
2006
影响因子：
4.4
通讯作者：
H. Abdala-Valencia;J. Cook-Mills
中科院分区：
文献类型：
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作者：
H. Abdala-Valencia;J. Cook-Mills
淋巴细胞与VCAM-1结合激活内皮细胞NADPH氧化酶，导致1 μ M H（2）O（2）的产生。这是VCAM-1依赖性淋巴细胞迁移所必需的。在这项研究中，我们确定了蛋白激酶Calpha（PKCalpha）在人和小鼠内皮细胞VCAM-1信号转导中的作用。用显性阴性PKCalpha或PKCalpha抑制剂Rö-32 - 0432或Gö-6976预处理内皮细胞，可阻断2达因/cm（2）层流下VCAM-1依赖性脾细胞迁移。PKCalpha（Thr 638）的磷酸化，一个自磷酸化位点，指示酶的活性，通过在内皮细胞上的VCAM-1的Ab交联或通过外源性添加1 μ M H（2）O（2）而增加。抗VCAM-1刺激的PKCalpha（Thr 638）磷酸化可通过清除H2 O2和抑制NADPH氧化酶来阻断。此外，抗VCAM-1信号转导诱导内皮细胞PKCalpha的氧化。氧化PKCalpha是PKCalpha的一种瞬时活性形式，不依赖于二酰基甘油。这种氧化作用可通过抑制NADPH氧化酶而被阻断。总之，内皮细胞NADPH氧化酶的VCAM-1活化诱导VCAM-1依赖性跨内皮细胞迁移所必需的瞬时PKCalpha活化。
Lymphocyte binding to VCAM-1 activates endothelial cell NADPH oxidase, resulting in the generation of 1 muM H(2)O(2). This is required for VCAM-1-dependent lymphocyte migration. In this study, we identified a role for protein kinase Calpha (PKCalpha) in VCAM-1 signal transduction in human and mouse endothelial cells. VCAM-1-dependent spleen cell migration under 2 dynes/cm(2) laminar flow was blocked by pretreatment of endothelial cells with dominant-negative PKCalpha or the PKCalpha inhibitors, Rö-32-0432 or Gö-6976. Phosphorylation of PKCalpha(Thr638), an autophosphorylation site indicating enzyme activity, was increased by Ab cross-linking of VCAM-1 on endothelial cells or by the exogenous addition of 1 muM H(2)O(2). The anti-VCAM-1-stimulated phosphorylation of PKCalpha(Thr638) was blocked by scavenging of H(2)O(2) and by inhibition of NADPH oxidase. Furthermore, anti-VCAM-1 signaling induced the oxidation of endothelial cell PKCalpha. Oxidized PKCalpha is a transiently active form of PKCalpha that is diacylglycerol independent. This oxidation was blocked by inhibition of NADPH oxidase. In summary, VCAM-1 activation of endothelial cell NADPH oxidase induces transient PKCalpha activation that is necessary for VCAM-1-dependent transendothelial cell migration.