2007 Fiscal Year Final Research Report Summary
Studies on dopamine neuron-specific dmenerative factor dopamine quinone in the pathogenesis of Parkinson's disease.
Project/Area Number |
17590878
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Neurology
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Research Institution | Okayama University |
Principal Investigator |
ASANUMA Masato Okayama University, Graduate School of Medicine, Dentistry and Pharmaceut. Sci., Dept. of Brain Science, Associate Professor (00273970)
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Co-Investigator(Kenkyū-buntansha) |
MIYAZAKI Ikuko Okayama University, Graduate School of Medicine, Dentistry and Pharmaceut. Sci. Dept. of Brain Science, Assistant Professor (40335633)
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Project Period (FY) |
2005 – 2007
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Keywords | PARKINSON'S DISEASE / DOPAIVHNE / DOPAMINE QUINONE / INTERACTING MOLECULE / NEURODEGENERATION / GLUTATHIONE / ASTROGLIAL CELL |
Research Abstract |
To clarify the possible roles of dopamine neuron-specific degenerative factor dopamine quinone in the pathogenesis of Parkinson's disease and to investigate therapeutic application of the dopamine quinone-regulating agents, we performed following experiments using dopaminergic neuronal cultured cells and hemi-parkinsonian model mice. 1. Screening of interacting molecules with dopamine or dopamine quinone By electron spin resonance method using in vitro dopamine quinone generating system, we identified metallothionein-1, some dopamine agonists and certain drug as dopamine quinone-interacting molecules. 2. Dopamine quinone-induced toxicity in cultured neuronal cells and effects of regulation of quinone-quenching system In dopaminergic CATH.a cells, dopamine quinone generated from excess free dopamine exerts neurotoxic effects. However, the dopamine-quinone-induced neurotoxicity was prevented by quenching of dopamine quinone, e.g. quinone reductase inducer, metallothionein inducer and a drug
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which enhances up-take of the substrate of glutathione synthesis in astroglial cells. 3. Changes in quinone-quenching system and effects of its regulation in parkinsonian animal models Several molecules of quinone-quenching system were activated in the lesioned striatum of hemi-parkinsonian mice. The drug, which interacts with dopamine quinone, enhanced astroglial proliferation, up-take of glutathione substrate in astroglial cells, and increased glutathione levels in the striatum. Furthermore, the drug ameliorated dopaminergic neuronal loss in the substantia nigra and inhibited repeated L-DOPA injections-induced elevation of protein-bound quinone (quinoprotein) in the striatum. Repeated L-DOPA administration markedly elevated striatal quinoprotein levels and reduced the dopaminergic nerve terminals specifically on the lesioned side in metallothionein-knockout parkinsonian mice, suggesting that intrinsic cysteine-rich molecule metallothionein protects against L-DOPA-induced dopamine quinone neurotoxicity in parkinsonian mice by its quinone-quenching property. These experimental results suggest a therapeutic potency of dopamine quinone-quenching agents for the patients of Parkinson's disease, and clarify that neuro-glial interaction on up-take of the substrate of glutathione synthesis plays a role in neuroprotective strategies against progressive dopaminergic neurodegeneration. Less
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Research Products
(102 results)