| Project/Area Number |
17590760
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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 |
Circulatory organs internal medicine
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| Research Institution | Kyoto Prefectural University of Medicine |
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Principal Investigator |
YAMADA Hiroyuki Kyoto Prefectural University of Medicine, Graduate School of Medicine, Assistant Professor, 医学研究科, 助教 (00240036)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUBARA Hiroaki Kyoto Prefectural University of Medicine, Graduate School of Medicine, Professor, 医学研究科, 教授 (10239072)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2005: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | angiotensin II / atherosclerosis / bone marrow cells / progenitors / receptors / アンジオテンシン |
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| Research Abstract |
Objective : The angiotensin II (Ang II) type 1 (AT_1) and type 2 (AT_2) receptor play a key roles in atherogenesis ; however, bone marrow (BM) AT_1 and AT_2-mediated actions remain undefined. The purpose of this study was to elucidate the effect of BM-AT_1 and BM-AT_2 on the pathogenesis of atherosclerosis development and vascular repair.
Methods and Results : (1) Atherosclerosis model ; ApoE-KO mice reconstituted with Agtrl^<-/->marrow (apoE-KO/BM-Agtrl^<-/->) showed a significant reduction in atherosclerotic lesions compared with apoE-KO/BM-Agtrl^<+/+> mice. The accumulation of monocytes/macrophages was attenuated in apoE-KO/BM-Agtrl^<-/->mice, concomitant with a decrease in the number of circulating Ly-6C^<hi> monocytes. Flow cytometric analysis of BM cells showed that the number of granulocyte/macrophage progenitors was much lower in apoE-KO/BM-Agtrl^<-/->mice, whereas the number of hematopoietic stem cells (HSCs) did not differ between the two groups, suggesting that BM-AT_1 promot
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es the transition from HSCs to macrophage progenitors. (2) Vascular repair model ; Total BM cells from Agtr1^<-/->, Agtr2^<-/->, or WT mice were transplanted into BM-ablated WT and femoral arterial injury was performed. Neointimal formation was markedly increased in BM-Agtr2^<-/->compared with BM-WT mice, whereas it was much lower in BM-Agtrl^<-/->mice. Circulating potential vascular progenitor cells, defined by c-kit-/lin-/Sca-1^+ markers, were markedly decreased in BM-Agtrl^<-/->mice, whereas CXR4^+ vascular progenitor cells markedly increased in BM-Agtr2^<-/->mice.
Conclusions : BM-AT_1 is closely implicated in the development of HSCs into macrophage progenitors and vascular progenitors, whereas BM-AT_2 is likely to modulate the property of monocyte/macrophage and vascular progenitors leading to the augmented mobilization from the bone marrow and accumulation at the site of vascular repair. Our study indicates that BM-AT_1 and BM-AT_2 could be a promising therapeutic target for the prevention of cardiovascular events. Less
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