Differential regulation of integrin-mediated proplatelet formation and megakaryocyte spreading.
Differential regulation of integrin-mediated proplatelet formation and megakaryocyte spreading.
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整合素介导的前血小板形成和巨核细胞扩散的差异调节。
DOI：
10.1002/jcp.1041630321
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Leven,RM
中科院分区：
文献类型：
--
作者：
Leven,RM
豚鼠骨髓巨核细胞在 I 型鼠尾胶原凝胶上培养，刺激前血小板形成。针对 αvβ3 整合素 (VnR) 的单克隆抗体 LM609 可抑制前血小板形成，但针对 α5、α6、β1 或 IIb beta3(GPIIb–IIIa) 整合素蛋白的单克隆抗体则不会抑制前血小板形成。在塑料表面培养并用凝血酶刺激的巨核细胞会发生铺展和粘附反应。该反应以剂量依赖性方式被四肽 RGDS 和针对 GPIIb-IIIa 整联蛋白的单克隆抗体 PG2 阻断，但不会被针对 VnR 的单克隆抗体 LM609 阻断。免疫沉淀和亲和层析实验表明，豚鼠巨核细胞具有独特的 GPIIb-IIIa 和 VnR 整合素，且具有相似的电泳迁移率。提高细胞环 AMP 的药物（包括毛喉素、二丁酰 cAMP 和异丁基甲基黄嘌呤）以剂量依赖性方式显着抑制扩散。与扩散相反，这些药物以剂量依赖性方式刺激巨核细胞前血小板形成。巨核细胞扩散受到蛋白激酶 C (PKC) 激活剂佛波醇肉豆蔻酸酯乙酸酯 (PMA) 的刺激，并受到 PKC 抑制剂 Calphostin C 和 K5720 的抑制，呈剂量依赖性。 PKC抑制剂不抑制巨核细胞前血小板的形成。这些结果表明，密切相关的 VnR 和 GPIIb-IIIa 整合素调节巨核细胞形态变化的不同方面，并且似乎与不同的第二信使系统相关。 © 1995 Wiley-Liss, Inc.
Guinea pig bone marrow megakaryocytes were cultured on a type I rat tail collagen gel which stimulated proplatelet formation. Proplatelet formation was inhibited by monoclonal antibody LM609 to the alphavbeta3integrin (VnR), but not by monoclonal antibodies to the alpha5, alpha6, beta1, or IIb beta3(GPIIb–IIIa)integrin proteins. Megakaryocytes cultured on a plastic surface and stimulated with thrombin undergo a spreading and an adhesion reaction. This reaction is blocked in a dose‐dependent manner by the tetrapeptide RGDS and by the monoclonal antibody PG2 to the GPIIb–IIIa integrin, but not by the monoclonal antibody LM609 to the VnR. Immunoprecipitation and affinity chromatography experiments demonstrate that guinea pig megakaryocytes have distinct GPIIb–IIIa and VnR integrins with similar electrophoretic mobility. Spreading was significantly inhibited in a dose‐dependent fashion by drugs which elevate cellular cyclic AMP, including forskolin, dibutyryl cAMP, and isobutylmethylxanthine. In contrast to spreading, megakaryocyte proplatelet formation was stimulated by these agents in a dose‐dependent manner. Megakaryocyte spreading was stimulated by the protein kinase C (PKC) activator phorbol myristate acetate (PMA) and inhibited by the PKC inhibitors Calphostin C and K5720 in a dose‐dependent manner. PKC inhibitors did not inhibit megakaryocyte proplatelet formation. These results demonstrate that the closely related VnR and GPIIb‐IIIa integrins regulate different aspects of megakaryocyte morphological change and appear to be associated with different second messenger systems. © 1995 Wiley‐Liss, Inc.