2000 年度実績報告書

エキサイトトキシンによる神経毒性出現メカニズムの解明研究

研究課題

研究課題/領域番号	10044328
研究機関	金沢大学
研究代表者	米田幸雄金沢大学, 薬学部, 教授 (50094454)
研究分担者	荻田喜代一摂南大学, 薬学部, 講師 (90169219)
キーワード	神経細胞死 / 神経毒 / NMDAレセプター / カインシ酸レセプター / 転写制御因子 / CA1野,CA3野錐体細胞 / 歯状,回顆粒細胞 / c-Fros蛋白質
研究概要	エキサイトトキシン類の神経毒性は、細胞膜上グルタミン酸レセプターを介して出現するが、3種類のイオノトロピック型サブタイプの中で、特にNMDA型とKA型サブタイプが神経細胞変性に強く関与する。本研究では、エキサイトトキシンによる神経毒性出現メカニズムに、特定機能蛋白質の「de novo」生合成が関与するとの仮説をうち立て、脳内における遺伝子転写調節に着目した。転写制御因子は、細胞核内で遺伝子DNAからmRNAへの転写を制御する核内蛋白質である。マウスにNMDAを全身的に適用すると、選択的にactivator protein-1(AP1)のDNA結合能上昇が、特に海馬の歯状回顆粒細胞層において強く認められたが、CA1野およびCA3野錐体細胞ではこのような増強は見られなかった。同様の解析を、KA全身適用マウスについても行った結果、歯状回顆粒細胞層だけでなく、CA1野およびCA3野錐体細胞層においても著明なAP1結合上昇が見出された。次いで、神経細胞層を含まない周辺領域についても検索を進めたところ、KA投与は各神経細胞層のみならず、周辺領域のAP1結合も著明に増強するのに対して、NMDA投与は周辺領域AP1結合には著変を与えないことが明らかとなった。KA投与後の海馬切片をニッスル染色により検討すると、NMDA投与2ヵ月後までいずれの神経層においても、海馬内神経細胞に著変は見出せなかったが、KA投与後3日以内には錐体細胞層において著しい神経細胞の脱落が誘発された。KA投与後2週間目には、CA1野およびCA3野錐体細胞は完全に脱落したが、歯状回顆粒細胞層には神経細胞脱落は見出せなかった。以上のように、本研究によりNMDAシグナルは一過性AP1結合上昇を、海馬歯状回顆粒細胞においてのみ招来するのに対して、KAシグナルは神経細胞層とは関係なく、海馬領域の広範囲に渡る持続的なAP1結合上昇を誘発することが明らかとなった。

研究成果
(23件)

すべてその他

すべて文献書誌 (23件)

[文献書誌] T.Manabe: "Differential in vitro degradation of particular Fros family members expressed by kainic acid……"J.Neurosci.Res.. (in press). (2001)
[文献書誌] K.Ogita: "Effects of glutathione depletion by 2-Cyclohexen-1-one on excitatoryamino acid-induced enhancement…… "J.Neurochem.. (in press). (2001)
[文献書誌] E.Hinoi: "Expression of GluR6/7 subunits of kainate receptors in rat adenohypophysis"Neurochem.Int.. (in press). (2001)
[文献書誌] Y.Yoneda: "Consolidation of transient ionotropic signals through nuclear transcription in the brain"Prog.Neurobiol.. 63. 697-719 (2001)
[文献書誌] E.Hinoi: "Group III metabotropic glutamate receptors in cultured rat calvarial osteoblasts"Biochem.Biophys.Res.Comm.. 281. 341-346 (2001)
[文献書誌] E.Hinoi: "Characterization with [3H] quisqualate of group I metabotropic glutamate receptor subtype………"Neurochem.Int.. 38. 277-285 (2001)
[文献書誌] T.Manabe.: "Differential expression and phosphorylation of particular Fros family members by kainic acid………"Neuroscience. 100. 453-463 (2000)
[文献書誌] J.Platenik: "Molecular mechanisms associated with long-term consolidation of the NMDA signals"Life Sci.. 67. 335-364 (2000)
[文献書誌] E.Hinoi: "Direct radio labeling by [3H] quisqualic acid of group I metabotropic glutamate receptor in rat brain……"Brain Res.. 881. 199-203 (2000)
[文献書誌] R.Janaky: "Glutathione and signal transduction in the"J.Neurochem.. 73. 889-902 (1999)
[文献書誌] T.Kitayama: "Sensitization by prolonged glutathion depletion of kainic acid to potentiate DNA binding activity……"Neurosci.Lett.. 269. 157-160 (1999)
[文献書誌] K.Ogita: "Differential inhibition by ferrous ions of [3H] MK-801 binding to native N-methyl-D-aspartate……"Brain Res.. 818. 548-552 (1999)
[文献書誌] K.Ogita.: "Preventive effects of exogenous phospholigases on inhibition by ferrous ion of [3H] MK-801 binding…"Neurochem.Int.. 34. 193-201 (1999)
[文献書誌] Y.Azuma: "Constitutive expression of cytoplasmic activator protein-1 with DNA binding activity and……"Neuroscience. 92. 1295-1308 (1999)
[文献書誌] Y.Yoneda: "Predominant expression of nuclear activator protein-1 complex with DNA binding activity following……"Neuroscience. 93. 19-31 (1999)
[文献書誌] T.Kitayama: "Sustained potentiation of AP1 DNA binding is not always associated with neuronal death……"Neurochem.Int.. 35. 453-462 (1999)
[文献書誌] Y.Yoneda: "N-Methyl-D-aspartate signaling in nuclear activator protein-1 through mechanisms different from……"Neuroscience. 90. 519-533 (1999)
[文献書誌] F.Stastny: "Ferrous iron modulates quinolinate-mediated [3H] MK-801 binding to rat brain synaptic……"Neurosci.Lett.. 262. 105-108 (1999)
[文献書誌] N.Karamoto: "Correlation between potentiation of AP1 DNA binding and expression of c-Fros in association with……"Brain Res.. 806. 152-164 (1998)
[文献書誌] K.Ogita: "Nitric-Oxide independent inhibition by sodium nitroprusside of the native N-methyl-D-aspartate…"Neurochem.Int.. 33. 6-9 (1998)
[文献書誌] Y.Yoneda: "Possible involvement of AP1 DNA binding in mechanisms underlying ischemic tolerance in the (A)……"Neuroscience. 86. 79-97 (1998)
[文献書誌] Y.Azuma: "Possible invivo crosstallc between transcription factors with zinc-finger and leucine-zipper……"Neurochem.Int.. 32. 325-336 (1998)
[文献書誌] Y.Yoneda: "Prolongation by bifemerane of potentiation of AP1 DNA binding in hippocampal CA1 subfield……"J.Neurosci.Res.. 51. 574-582 (1998)

2000 年度 実績報告書

エキサイトトキシンによる神経毒性出現メカニズムの解明研究

研究代表者

米田 幸雄 金沢大学, 薬学部, 教授 (50094454)

研究成果

[文献書誌] T.Manabe: "Differential in vitro degradation of particular Fros family members expressed by kainic acid……"J.Neurosci.Res.. (in press). (2001)

[文献書誌] K.Ogita: "Effects of glutathione depletion by 2-Cyclohexen-1-one on excitatoryamino acid-induced enhancement…… "J.Neurochem.. (in press). (2001)

[文献書誌] E.Hinoi: "Expression of GluR6/7 subunits of kainate receptors in rat adenohypophysis"Neurochem.Int.. (in press). (2001)

[文献書誌] Y.Yoneda: "Consolidation of transient ionotropic signals through nuclear transcription in the brain"Prog.Neurobiol.. 63. 697-719 (2001)

[文献書誌] E.Hinoi: "Group III metabotropic glutamate receptors in cultured rat calvarial osteoblasts"Biochem.Biophys.Res.Comm.. 281. 341-346 (2001)

[文献書誌] E.Hinoi: "Characterization with [3H] quisqualate of group I metabotropic glutamate receptor subtype………"Neurochem.Int.. 38. 277-285 (2001)

[文献書誌] T.Manabe.: "Differential expression and phosphorylation of particular Fros family members by kainic acid………"Neuroscience. 100. 453-463 (2000)

[文献書誌] J.Platenik: "Molecular mechanisms associated with long-term consolidation of the NMDA signals"Life Sci.. 67. 335-364 (2000)

[文献書誌] E.Hinoi: "Direct radio labeling by [3H] quisqualic acid of group I metabotropic glutamate receptor in rat brain……"Brain Res.. 881. 199-203 (2000)

[文献書誌] R.Janaky: "Glutathione and signal transduction in the"J.Neurochem.. 73. 889-902 (1999)

[文献書誌] T.Kitayama: "Sensitization by prolonged glutathion depletion of kainic acid to potentiate DNA binding activity……"Neurosci.Lett.. 269. 157-160 (1999)

[文献書誌] K.Ogita: "Differential inhibition by ferrous ions of [3H] MK-801 binding to native N-methyl-D-aspartate……"Brain Res.. 818. 548-552 (1999)

[文献書誌] K.Ogita.: "Preventive effects of exogenous phospholigases on inhibition by ferrous ion of [3H] MK-801 binding…"Neurochem.Int.. 34. 193-201 (1999)

[文献書誌] Y.Azuma: "Constitutive expression of cytoplasmic activator protein-1 with DNA binding activity and……"Neuroscience. 92. 1295-1308 (1999)

[文献書誌] Y.Yoneda: "Predominant expression of nuclear activator protein-1 complex with DNA binding activity following……"Neuroscience. 93. 19-31 (1999)

[文献書誌] T.Kitayama: "Sustained potentiation of AP1 DNA binding is not always associated with neuronal death……"Neurochem.Int.. 35. 453-462 (1999)

[文献書誌] Y.Yoneda: "N-Methyl-D-aspartate signaling in nuclear activator protein-1 through mechanisms different from……"Neuroscience. 90. 519-533 (1999)

[文献書誌] F.Stastny: "Ferrous iron modulates quinolinate-mediated [3H] MK-801 binding to rat brain synaptic……"Neurosci.Lett.. 262. 105-108 (1999)

[文献書誌] N.Karamoto: "Correlation between potentiation of AP1 DNA binding and expression of c-Fros in association with……"Brain Res.. 806. 152-164 (1998)

[文献書誌] K.Ogita: "Nitric-Oxide independent inhibition by sodium nitroprusside of the native N-methyl-D-aspartate…"Neurochem.Int.. 33. 6-9 (1998)

[文献書誌] Y.Yoneda: "Possible involvement of AP1 DNA binding in mechanisms underlying ischemic tolerance in the (A)……"Neuroscience. 86. 79-97 (1998)

[文献書誌] Y.Azuma: "Possible invivo crosstallc between transcription factors with zinc-finger and leucine-zipper……"Neurochem.Int.. 32. 325-336 (1998)

[文献書誌] Y.Yoneda: "Prolongation by bifemerane of potentiation of AP1 DNA binding in hippocampal CA1 subfield……"J.Neurosci.Res.. 51. 574-582 (1998)

2000 年度実績報告書

米田幸雄金沢大学, 薬学部, 教授 (50094454)