| Project/Area Number |
15591398
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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 |
Digestive surgery
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| Research Institution | Nagoya University |
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Principal Investigator |
NAGINO Masato Nagoya University, Graduate School of Medicine, Associate Professor, 大学院・医学系研究科, 助教授 (20237564)
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| Co-Investigator(Kenkyū-buntansha) |
NIMURA Yuji Nagoya University, Graduate School of Medicine, Professor, 大学院・医学系研究科, 教授 (80126888)
ODA Koji Nagoya University, University Hospital, Research Associate, 医学部附属病院, 助手 (30311715)
ARAI Toshiyuki Nagoya University, University Hospital, Research Associate, 医学部附属病院, 助手 (80335041)
NISHIO Hideki Nagoya University, University Hospital, Research Associate, 医学部附属病院, 助手 (30345897)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2004: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2003: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | liver regeneration / portal vein embolization / endothelial cell / continuous stretch / interleukin-6 / NF-κB / integrin / mechanotransduction / 伸展刺激 / IL-6 / NF-κB / IKKα |
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| Research Abstract |
We previously reported that uni-axial continuous stretch in human umbilical vein endothelial cells(HUVECs) induced IL-6 secretion via I κ B kinases(IKKs)/nuclear factor-κB(NF-κB) activation (Kobayashi, et al., 2003). The aim of this study is to clarify the upstream signaling mechanism responsible for this phenomenon.
The stretch-induced IKKs activation, IL-6mRNA expression and IL-6 secretion were inhibited by an application of α 5 β 1 integrin inhibitory peptide : GRGDNP, phosphatidylinositol 3-kinase inhibitor : LY294002,phospholipase Cγ inhibitor : U73122,protein kinase C inhibitor : H7 or the depletion of intra-and extra-cellular Ca^<2+> pools by a co-application of EGTA and thapsigargin(TG), but not by the depletion of extracellular Ca^<2+> by EGTA or the depletion of intracellular Ca^<2+> stores by TG. Using fura-2 fluorescence intensity ratiometry, a transient increase in intracellular Ca^<2+> concentration (Ca^<2+>]_i) upon continuous stretch was observed in the presence of Gd^<3+>, EGTA, TG or GRGDNP, but not with a mixture EGTA and TG, suggesting that both a [Ca^<2+>]_i rise and integrin activation are crucial to elicit IKKs activation and IL-6 secretion in HUVECs. It seemed like that either Ca^<2+> influx via SA channels or Ca^<2+> release from intracellular stores is enough to activate the downstream signaling cascade for IL-6 secretion. PKC kinase activity was inhibited by an application of GRGDNP, LY294002 or U73122, and PLC γ kinase activity was by GRGDNP or LY294002.
These results indicate that continuous stretch-induced IL-6 secretion in HUVECs is dependent on both outside-in signaling at integrins and a [Ca^<2+>]_i rise followed by a PI3-K/PLCγ/PKC/IKKs/NF-κB signaling pathway.
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