| Project/Area Number |
04670570
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | NATIIONAL CARDIOVASCULAR CENTER RESEARCH INSTITUTE |
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Principal Investigator |
SHIMOKADO Kentaro NATIIONAL CARDIOVASCULAR CENTER RESEARCH INSTITUTE, HEAD OF LABORATORY, 循環動態機能部, 室長 (30192115)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1993: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1992: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | smooth muscle cells / proliferation / chemotaxis / tyrosine phosphorylation / PTCA / restenosis / PTK inhibitors / colchicinet / 血管内膜肥厚 / 増殖因子 / チロジンキナーゼ阻害剤 / PTCA後再狭窄 |
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| Research Abstract |
Smooth muscle cell (SMC) accumulation which is induced by growth factors is a key event in the development of the restenosis after percutaneous transluminal coronary angioplasty (PTCA). Tyrosine phosphorylation is an important mechanism for transducing the signal of growth factors. Thus an inhibitor of protein tyrosine kinase (PTK) is potentially useful for the treatment of the restenosis. We investigated the effect of PTK inhibitors on PDGF-induced proliferation and migration of rat aortic SMCs invitro. Two PTK inhibitors with different modes of action, methyl 2, 5-dihydroxy cinnamate (2, 5-MC) and genistein (Gen) inhibited the PDGF-induced DNA synthesis of SMCs in a dose dependent fashion (IC50=4.5 muM and 4 muM, respectively). This inhibition of DNA synthesis was reversible upon removal of the inhibitor. Cell cycle analysis revealed that the inhibitor blocked at least three points of the cell cycle ; G1, S and M phase. Both inhibitors also inhibited PDGF-induced chemotaxis of SMCs in a modified Boden assay (IC50=5 muM and 150 muM, respectively). Gen and 2, 5-MC partly inhibited the adhesion of SMCs to collagen-coated dishes. A chemotaxis assayusing double-well dishes revealed that both agents also inhibited cell migration after adhesion. H7, a C kinaseinhibitor, did not inhibit either chemotaxis or SMC adhesion at 100 muM.An immunocytochemical study revealed that PTK inhibitors eliminated tyrosine-phosphorylation along the cell margins ; PTK inhibitors also inhibited the recognization of microtublules and stress bivers, both of which are involved in cell proliferation and migration. Western blot analysis using anti-hosphotyrosine monoclonal antibody revealed that PTK inhibitors inhibited the tyrosine-phosphorylation of at least two proteins with molecular weight 85 kD and95 kD under our experimental conditions. PTK inhibitors may be usefl for the treatment of restenosis.
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