1991 年度実績報告書

ミトコンドリア遺伝子病における変異解析

研究課題

研究課題/領域番号	03044072
研究機関	名古屋大学
研究代表者	小澤高將名古屋大学, 医学部, 教授 (80022771)
研究分担者	NAGLEY Phill モナッシュ大学, 生化学系, 教授 LINNANE W.An モナッシュ大学, 生化学系, 教授田中雅嗣名古屋大学, 医学部, 助教授 (60155166)
キーワード	ミトコンドリアDNA / 電子伝達系酵素欠損 / ミトコンドリア脳筋症 / 遺伝子変異 / 欠失 / 活性酸素ラジカル / 加齢現象 / 退行性病変
研究概要	ミトコンドリアDNA(mtDNA)変異蓄積の機構について重点的に本年度の研究を行なった。 1.これまでに30例以上のヒト個体においてmtDNAの全塩基配列を決定し、合計50万塩基対のデ-タを得た。蛋白質を規定する翻訳領域に250ケ所の点変異が見いだされた。同義置換が高い頻度で生じていたが、非同義置換を引き起こす変異も、同様に、高い頻度で生じていた。実際にアミノ酸の変化を引き起こす非同義置換の割合は35%に達した。このうち有害性の強い変異は、世代から世代へ伝達されず、流産・早産ないし小児疾患として発現し、有害性の弱い変異遺伝子は、その遺伝子を持った個体が生殖年齢に達した後に異常な形質として発現する、あるいは特定の外的、内的因子に曝された時にはじめて疾患として顕在化するものと考えられた。 2.本研究によって、個体が加齢あるいは疾患に伴って変異を獲得する体細胞変異が、極めて速い速度で起きることが初めて明らかにされた。特に細胞分裂終了細胞から構成される中枢神経系あるいは筋組織において顕著であった。許容される変異遺伝子の量がある一定の閾値を越えると疾患として発現してくる。この閾値はパ-キンソン病の黒質線条体のmtDNAで約5%であった。 3.mtDNA変異の蓄積の機構において、電子伝達系から漏出する活性酸素ラジカルによるmtDNAの損傷が重要であること明らかにした。心筋あるいは横隔膜のmtDNAを加水分解し、その質量分析により8ーOHーdGを定量すると同時に、欠失mtDNAをPCR増幅法により解析した。その結果、加齢に伴って8ーOHーdGの量と欠失mtDNAの量が平行して指数関数的に増大することを初めて示した。酸化的損傷によって生じた8ーヒドロキシデオキシグアノシン(8ーOHーdG)が二次的にmtDNAの点変異や欠失を引き起こすものと考えられる。

研究成果

(24件)

すべてその他

すべて文献書誌 (24件)

[文献書誌] E.Byrne: "Functional respiratory chain studies in mitochondrial cytopathies.Support for mitochondrial DNA heteroplasmy in myoclonus epilepsy and ragged red fibers (MERRF) syndrome" Acta Neuropathol.(Berl). 813. 18-323 (1991)
[文献書誌] K.Hattori: "Age-dependent increase in deleted mitochondrial DNA in the human heart:possible contributory factor to presbycardia" Am.Heart J.121. 1735-1742 (1991)
[文献書誌] M.Hayakawa: "Massive conversion of guanosine to 8-hydroxy-guanosine in mouse liver mitochondrial DNA by administration of azidothymidine" Biochem.Biophys.Res.Commun.176. 87-93 (1991)
[文献書誌] M.Hayakawa: "Age-associated accumulation of 8-hydroxydeoxyguanosine in mitochondrial DNA of human diaphragm" Biochem.Biophys.Res.Commun.179. 1023-1029 (1991)
[文献書誌] H.Ino: "Mitochondrial leucine tRNA mutation in a mitochondrial encephalomyopathy" Lancet. 337. 234-235 (1991)
[文献書誌] M.Katayama: "Deleted mitochondrial DNA in the skeletal muscle of aged individuals" Biochem.Int.25. 47-56 (1991)
[文献書誌] K.Ohno: "Direct DNA sequencing from colony:analysis of multiple deletions of mitochondrial genome" Biochim.Biophys.Acta. 1090. 9-16 (1991)
[文献書誌] K.Ohno: "Mitochondrial DNA deletions in inherited recurrent myoglobinuria" Ann.Neurol.29. 364-369 (1991)
[文献書誌] Y.Ota: "Detection of platelet mitochondrial DNA deletions in Kearns-Sayre syndrome" Inv.Ophthalmol.Vis.Sci.32. 2667-2675 (1991)
[文献書誌] T.Ozawa: "Distinct clustering of point mutations in mitochondrial DNA among patients with mitochondrial encephalomyopathies and with Parkinson's disease" biochem.Biophys.Res.Commun.176. 938-46 (1991)
[文献書誌] T.Ozawa: "Patients with idiopathic cardiomyopathy belong to the same mitochondrial DNA gene family of Parkinson's disease and mitochondrial encephalomyopathy" Biochem.Biophys.Res.Commun.177. 518-525 (1991)
[文献書誌] M.Tanaka: "Mitochondrial DNA mutations in mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episodes (MELAS)" Biochem.Biophys.Res.Commun.174. 861-868 (1991)
[文献書誌] D.Nero: "Site directed mutagenesis of subunit 8 of yeast mitochondrial ATP synthase.Functional and import properties of a series of C-terminally truncated forms" FEBS Lett. 270. 62-66 (1990)
[文献書誌] A.W.Linnane: "Mitochondrial gene mutation:the ageing process and degenerative diseases" Biochem.Int.22. 1067-1076 (1990)
[文献書誌] P.Nagley: "Coordination of gene expression in the formation of mammalian mitochondria" Treands.Genet.7. 1-4 (1991)
[文献書誌] F.Vaillant: "Some biological properties of human lymphoblastoid Namalwa cells grown anaerobically" Biochem.Int.23. 571-580 (1991)
[文献書誌] D.G.Grasso: "The C-terminal positively charged region of subunit 8 of yeast mitochondrial ATP synthase is required for efficient assembly of this protein into the membrane F_0 sector" Eur.J.Biochem. 199. 203-209 (1991)
[文献書誌] M.Granis: "Duplication of leader sequence for protein targeting to mitochondria leads to increases import efficiency" Fed.Eur.Biochem.Soc.Lett. 282. 425-430 (1991)
[文献書誌] K.Hattori: "A case report of cardiomyopathy with mitochondrial DNA mutations" Am.Heart J.(1992)
[文献書誌] K.Sahashi: "Increased mitochondrial DNA deletions in the skeletal muscle of myotonic dystrophy" J.Gerontol.(1992)
[文献書誌] K.Torii: "Aging-associated deletions of human diaphragmatic mitochondrial DNA" Am.J.Respir.Cell.Mol.Biol.(1992)
[文献書誌] H.Yamamoto: "Significant Existence of Deleted Mitochondrial DNA in Cirrhotic Liver Surrounding Hepatic Tumor" Biochem.Biophys.Res.Comun.182. 913-920 (1992)
[文献書誌] M.Tanaka: ""Mitochondrial DNA mutations in mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episodes (MELAS)."" Techniques of Molecular Neurobiology.Langstaff ed.Humana Press.Clifton., (1992)
[文献書誌] A.W.Linnane: "Mitochondrial disease and the ageing process:from microbe to man" Molecular Biology of the Myocardium.Japan Scientific societies Press, (1992)

1991 年度 実績報告書

ミトコンドリア遺伝子病における変異解析

研究代表者

小澤 高將 名古屋大学, 医学部, 教授 (80022771)

研究成果

[文献書誌] E.Byrne: "Functional respiratory chain studies in mitochondrial cytopathies.Support for mitochondrial DNA heteroplasmy in myoclonus epilepsy and ragged red fibers (MERRF) syndrome" Acta Neuropathol.(Berl). 813. 18-323 (1991)

[文献書誌] K.Hattori: "Age-dependent increase in deleted mitochondrial DNA in the human heart:possible contributory factor to presbycardia" Am.Heart J.121. 1735-1742 (1991)

[文献書誌] M.Hayakawa: "Massive conversion of guanosine to 8-hydroxy-guanosine in mouse liver mitochondrial DNA by administration of azidothymidine" Biochem.Biophys.Res.Commun.176. 87-93 (1991)

[文献書誌] M.Hayakawa: "Age-associated accumulation of 8-hydroxydeoxyguanosine in mitochondrial DNA of human diaphragm" Biochem.Biophys.Res.Commun.179. 1023-1029 (1991)

[文献書誌] H.Ino: "Mitochondrial leucine tRNA mutation in a mitochondrial encephalomyopathy" Lancet. 337. 234-235 (1991)

[文献書誌] M.Katayama: "Deleted mitochondrial DNA in the skeletal muscle of aged individuals" Biochem.Int.25. 47-56 (1991)

[文献書誌] K.Ohno: "Direct DNA sequencing from colony:analysis of multiple deletions of mitochondrial genome" Biochim.Biophys.Acta. 1090. 9-16 (1991)

[文献書誌] K.Ohno: "Mitochondrial DNA deletions in inherited recurrent myoglobinuria" Ann.Neurol.29. 364-369 (1991)

[文献書誌] Y.Ota: "Detection of platelet mitochondrial DNA deletions in Kearns-Sayre syndrome" Inv.Ophthalmol.Vis.Sci.32. 2667-2675 (1991)

[文献書誌] T.Ozawa: "Distinct clustering of point mutations in mitochondrial DNA among patients with mitochondrial encephalomyopathies and with Parkinson's disease" biochem.Biophys.Res.Commun.176. 938-46 (1991)

[文献書誌] T.Ozawa: "Patients with idiopathic cardiomyopathy belong to the same mitochondrial DNA gene family of Parkinson's disease and mitochondrial encephalomyopathy" Biochem.Biophys.Res.Commun.177. 518-525 (1991)

[文献書誌] M.Tanaka: "Mitochondrial DNA mutations in mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episodes (MELAS)" Biochem.Biophys.Res.Commun.174. 861-868 (1991)

[文献書誌] D.Nero: "Site directed mutagenesis of subunit 8 of yeast mitochondrial ATP synthase.Functional and import properties of a series of C-terminally truncated forms" FEBS Lett. 270. 62-66 (1990)

[文献書誌] A.W.Linnane: "Mitochondrial gene mutation:the ageing process and degenerative diseases" Biochem.Int.22. 1067-1076 (1990)

[文献書誌] P.Nagley: "Coordination of gene expression in the formation of mammalian mitochondria" Treands.Genet.7. 1-4 (1991)

[文献書誌] F.Vaillant: "Some biological properties of human lymphoblastoid Namalwa cells grown anaerobically" Biochem.Int.23. 571-580 (1991)

[文献書誌] D.G.Grasso: "The C-terminal positively charged region of subunit 8 of yeast mitochondrial ATP synthase is required for efficient assembly of this protein into the membrane F_0 sector" Eur.J.Biochem. 199. 203-209 (1991)

[文献書誌] M.Granis: "Duplication of leader sequence for protein targeting to mitochondria leads to increases import efficiency" Fed.Eur.Biochem.Soc.Lett. 282. 425-430 (1991)

[文献書誌] K.Hattori: "A case report of cardiomyopathy with mitochondrial DNA mutations" Am.Heart J.(1992)

[文献書誌] K.Sahashi: "Increased mitochondrial DNA deletions in the skeletal muscle of myotonic dystrophy" J.Gerontol.(1992)

[文献書誌] K.Torii: "Aging-associated deletions of human diaphragmatic mitochondrial DNA" Am.J.Respir.Cell.Mol.Biol.(1992)

[文献書誌] H.Yamamoto: "Significant Existence of Deleted Mitochondrial DNA in Cirrhotic Liver Surrounding Hepatic Tumor" Biochem.Biophys.Res.Comun.182. 913-920 (1992)

[文献書誌] M.Tanaka: ""Mitochondrial DNA mutations in mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episodes (MELAS)."" Techniques of Molecular Neurobiology.Langstaff ed.Humana Press.Clifton., (1992)

[文献書誌] A.W.Linnane: "Mitochondrial disease and the ageing process:from microbe to man" Molecular Biology of the Myocardium.Japan Scientific societies Press, (1992)

1991 年度実績報告書

小澤高將名古屋大学, 医学部, 教授 (80022771)