2000 Fiscal Year Final Research Report Summary
Analysis of the Activation of Platelet Integrin α2β1 and its Physiological Function
| Project/Area Number |
11680709
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Cell biology
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| Research Institution | Kurume University |
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Principal Investigator |
MASAAKI Moroi Kurume University, Institute of Life Science, Professor, 分子生命科学研究所, 教授 (00049074)
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| Co-Investigator(Kenkyū-buntansha) |
ICHIRO Onitsuka Kurume University, Department of Medicine, Research Associate, 医学部, 助手 (10289431)
YOSHIKI Miura Kurume University, Institute of Life Science, Research Associate, 分子生命科学研究所, 助手 (90279240)
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| Project Period (FY) |
1999 – 2000
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| Keywords | PLATELET / COLLAGEN / INTEGRIN α2β1 / GPVI / ADP RECEPTOR |
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| Research Abstract |
1. We analyzed the activation of integrin α2β1 of platelets as assessed by binding of solublc collage. We found that the integrin α2β1 of platelets activated by thrombin showed higher affinity for collagen that of ADP-activated platelets, indicating the different conformation of these integrin α2βls. The analysis using different kinds ofinhibitors also indicated the different inhibitory effects on the integrin activation in thrombin- and ADP-activated platelets (J Bid Chem 275, 8016, 2000). Using inhibitors specific for two ADP receptors, P2Y1 and P2T, we showed that integrin α2β1 activation is effected through the differential involvement of two ADP receptors and intracellular Ca increase is not directly related to integrin α2β1 activation.
2. We analyzed the contribution of integrin α2βl activation to the platelet adhesion to collagen surface under blood flow using integrin activating antibody and inhibiting antibody. The results suggested the activated integrin α2βl induced tight binding of platelets to collagen surface and the activation of integrin α2βl would occur under these conditions.(Thromb Haemostas 83, 769, 2000) We also analyzed platelet adhesion to thrombospondin-coated surface under flow conditions. Platelets showed very weak interaction with thrombospondin surface.
3. Glycoprotein (GP) VI is another collagen receptor of platelets. We purified GPVI from platelet membrane and identified its amino acid sequence from cDNA cloning. GPVI belongs to immunoglobulin receptor superfamily and contained Arg residue in its transmembrane domain which make a complex with Fc receptor γ chain. (Thromb Res98,301, 2000)
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