2000 Fiscal Year Annual Research Report

アルツハイマ・病におけるニューロン変性機序の解明

Research Project

Project/Area Number	12210084
Research Institution	Kyoto University
Principal Investigator	下濱俊京都大学, 医学研究科, 講師 (60235687)
Keywords	アルツハイマー病 / Aβ(βアミロイド) / グルタミン酸 / ニコチン / α7受容体 / ニコチン性受容体 / PI3K / Fyn
Research Abstract	初代培養ラット大脳神経細胞を用いた。Aβ1-40(1nM)、1-42(100pM)を同時投与下7日間培養後、グルタミン酸(20μM)を24時間投与したところ、毒性は有意に増強された。この細胞死はNMDA受容体遮断薬(MK801)で抑制された。Aβと同時にニコチン(0.5μM、7日間)を投与したところ、増強されたグルタミン酸毒性は抑制された。グルタミン酸単独(50μM、24時間)で誘発した細胞死も同様に、ニコチンを前投与(10μM、24時間)した群で抑制された。この保護効果はα7ニコチン性受容体拮抗薬であるαブンガロトキシンで遮断されるとともにPI3Kインヒビター(LY294002)で抑制された。また、非受容体型チロシンキナーゼの遮断薬であるPP2がニコチンの保護効果を抑制した。ニコチン処置後抽出したサンプルでPI3Kの標的酵素、Aktの活性化型(リン酸化型)Aktの増加を認めた。ニコチンの保護効果及びAktリン酸化はαプンガロトキシン、LY294002、PP2で抑制された。さらに、ニコチン処置群では抗アポトーシス効果を持つBcl-2やBcl-xの発現が増大していた。α7受容体抗体を用いた免疫沈降で得たタンパクで行ったイムノプロットでPI3Kp85サプユニットが見出された。また、非受容体型チロシンキナーゼであるSrcファミリーのFynが認められた。それぞれの抗体で行った免疫沈降サンプルからα7受容体が見出され、これらが会合している可能性が示された。以上の結果より、ニコチン性受容体刺激はグルタミン酸毒性から神経細胞を保護する機構を持ち、その機構にはPI3K-Akt-Bcl-2の系が寄与している。また、α7受容体-Fynがこの系に関与していることが示唆された。

Research Products
(18 results)

All Other

All Publications (18 results)

[Publications] Kume T,Nishikawa H et al: "P75-mediated neuroprotection by NGF against glutamate cytotoxicity in cortical cultures"Brain Research. 852. 279-289 (2000)
[Publications] Kageyama T,Oeda.T. et al: "Cooxistence of expanded CAG repeats in the MJDla and DRPLA genes"Neurology. 54. 265-266 (2000)
[Publications] Yamamoto K,Hashiwoto K et al: "Au IPs-assisted form of Ca^<2+>-induced Ca^<2+> release in neocortical neurons"Neuroreport. 11. 535-539 (2000)
[Publications] Sawada H,Ib,M et al: "Neuroprotective mechanism of glial cell line-derived neurotrophic factor in mesercephalic neurons"Journal of Neurochemistry. 74. 1175-1184 (2000)
[Publications] Houda K,Sawada H et al: "Phosphatidylinositol 3-kinase mediates neuroprotection by estrogew in cultured cortical neurons"Journal of Neuroscience Research. 60. 321-327 (2000)
[Publications] Sawada H,Ibi M et al: "Mechanisms of antiapoptotic effects of estrogen in nigral dopaminorgic neuron"FASEB Journal. 14. 1202-1214 (2000)
[Publications] Tanino H,Shimohama S et al: "Increase in phospholipase C-α_1 protein levels in aluminum-treated rat brains"Biochew Biophys Res Commun. 271. 620-625 (2000)
[Publications] Shimohama S,Tanino H et al: "Activation of NADPH oxidase in Alzheimer's disease brains"Biochem Biophys Res Commun. 273. 5-9 (2000)
[Publications] Urushitani M,Inoeu R et al: "Neuroprotective effect of cyclic GMP against radical-induced toxicity in cultured spinal motor neurons"Journal of Neuroscience Research. 61. 443-448 (2000)
[Publications] Kageyama T,Nakawura M et al: "The 4F2hc/LAT1 complex transports L-Dopa across the blood-brain barrier"Brain Research. 879. 115-121 (2000)
[Publications] Imura T,Shimohama S: "Opposing effects of adenosine on the survival of glial cells exposed to chemical ischemia"Journal of Neuroscience Research. 62. 539-546 (2000)
[Publications] Nakanizo T,Urushitani M et al: "Protection of motor neurons by estradiol"Neuro report. 11. 3493-3497 (2000)
[Publications] Kakimura J,Kitamura Y et al: "Bip/GRP75-induced protection of cytokines and uptake of amyloid-β(1-42) peptide in microglia"Biochem Biophys Res Commun. 281. 6-10 (2001)
[Publications] Kageyama T,Imura T et al: "Distribution of the 4F2 light chain, LAT1, in the mouse brain"Neuroreport. 11. 3663-3666 (2000)
[Publications] Urushitani M,Nakamizo T et al: "NMDA receptor-mediated mitochondrial Ca^<2+> overload in acute excitotoxic motor neurons death : a distinct mechanism from chronic neuro toxicity after Ca^<2+> influx"Journal of Neuroscience Research. 63. 377-387 (2001)
[Publications] Shimohamw S,Kihara T: "Nicotinic receptor-mediated protection against beta amyloid neurotoxicity"Biological Psychiatry. (in press). (2001)
[Publications] Kihara T,Shimohama S et al: "Alpha 7 nicotinic receptor transduces signals to PI3 kinase to block Aβ-induced neurotoxicity"Journal of Biological Chemistry. (in press). (2001)
[Publications] Honda K,Shimohama S et al: "Nougenomic antiapoptotic signal transduction by estrogen in cultured cortical neurons"Journal of Neuroscience Research. (in press). (2001)

2000 Fiscal Year Annual Research Report

アルツハイマ・病におけるニューロン変性機序の解明

Principal Investigator

下濱 俊 京都大学, 医学研究科, 講師 (60235687)

Research Products

[Publications] Kume T,Nishikawa H et al: "P75-mediated neuroprotection by NGF against glutamate cytotoxicity in cortical cultures"Brain Research. 852. 279-289 (2000)

[Publications] Kageyama T,Oeda.T. et al: "Cooxistence of expanded CAG repeats in the MJDla and DRPLA genes"Neurology. 54. 265-266 (2000)

[Publications] Yamamoto K,Hashiwoto K et al: "Au IPs-assisted form of Ca^<2+>-induced Ca^<2+> release in neocortical neurons"Neuroreport. 11. 535-539 (2000)

[Publications] Sawada H,Ib,M et al: "Neuroprotective mechanism of glial cell line-derived neurotrophic factor in mesercephalic neurons"Journal of Neurochemistry. 74. 1175-1184 (2000)

[Publications] Houda K,Sawada H et al: "Phosphatidylinositol 3-kinase mediates neuroprotection by estrogew in cultured cortical neurons"Journal of Neuroscience Research. 60. 321-327 (2000)

[Publications] Sawada H,Ibi M et al: "Mechanisms of antiapoptotic effects of estrogen in nigral dopaminorgic neuron"FASEB Journal. 14. 1202-1214 (2000)

[Publications] Tanino H,Shimohama S et al: "Increase in phospholipase C-α_1 protein levels in aluminum-treated rat brains"Biochew Biophys Res Commun. 271. 620-625 (2000)

[Publications] Shimohama S,Tanino H et al: "Activation of NADPH oxidase in Alzheimer's disease brains"Biochem Biophys Res Commun. 273. 5-9 (2000)

[Publications] Urushitani M,Inoeu R et al: "Neuroprotective effect of cyclic GMP against radical-induced toxicity in cultured spinal motor neurons"Journal of Neuroscience Research. 61. 443-448 (2000)

[Publications] Kageyama T,Nakawura M et al: "The 4F2hc/LAT1 complex transports L-Dopa across the blood-brain barrier"Brain Research. 879. 115-121 (2000)

[Publications] Imura T,Shimohama S: "Opposing effects of adenosine on the survival of glial cells exposed to chemical ischemia"Journal of Neuroscience Research. 62. 539-546 (2000)

[Publications] Nakanizo T,Urushitani M et al: "Protection of motor neurons by estradiol"Neuro report. 11. 3493-3497 (2000)

[Publications] Kakimura J,Kitamura Y et al: "Bip/GRP75-induced protection of cytokines and uptake of amyloid-β(1-42) peptide in microglia"Biochem Biophys Res Commun. 281. 6-10 (2001)

[Publications] Kageyama T,Imura T et al: "Distribution of the 4F2 light chain, LAT1, in the mouse brain"Neuroreport. 11. 3663-3666 (2000)

[Publications] Urushitani M,Nakamizo T et al: "NMDA receptor-mediated mitochondrial Ca^<2+> overload in acute excitotoxic motor neurons death : a distinct mechanism from chronic neuro toxicity after Ca^<2+> influx"Journal of Neuroscience Research. 63. 377-387 (2001)

[Publications] Shimohamw S,Kihara T: "Nicotinic receptor-mediated protection against beta amyloid neurotoxicity"Biological Psychiatry. (in press). (2001)

[Publications] Kihara T,Shimohama S et al: "Alpha 7 nicotinic receptor transduces signals to PI3 kinase to block Aβ-induced neurotoxicity"Journal of Biological Chemistry. (in press). (2001)

[Publications] Honda K,Shimohama S et al: "Nougenomic antiapoptotic signal transduction by estrogen in cultured cortical neurons"Journal of Neuroscience Research. (in press). (2001)

下濱俊京都大学, 医学研究科, 講師 (60235687)