Residual substantia nigra neuromelanin in Parkinson's disease is cross-linked to alpha-synuclein.
Neurochem Int
; 42(7): 603-6, 2003 Jun.
Article
en En
| MEDLINE
| ID: mdl-12590943
ABSTRACT
The pigmentation of substantia nigra pars compacta dopaminergic neurons is due to the presence of neuromelanin, an irregular macromolecular pigment belonging to the family of melanins. Depletion of neuromelanin in Parkinson's disease is typically indicated by loss of brown color in this area. Unlike that from controls, the pigment extracted from substantia nigra of parkinsonian patients seems to be mainly composed by highly cross-linked, protease-resistant proteic material and the neuromelanin macromolecule appears to be a minor presence. In the present paper we describe the isolation by SDS-PAGE of this proteic component after cleavage of the melanin backbone under solubilizing conditions. A single band is observed, which has been identified as alpha-synuclein by western blotting. As expected, the same process performed on a control specimen did not show occurrence of any major proteic component. Nevertheless, extraction from a 91 years old control with Lewy bodies displayed minor alpha-synuclein immunoreactive aggregates, whereas inclusion of free alpha-synuclein was not observed at all. Results reported here support the view that alpha-synuclein accumulates within substantia nigra neurons and is entrapped in pigment granules during neuromelanin biosynthesis, i.e. before the melanin depletion characteristic of Parkinson's disease starts.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Enfermedad de Parkinson
/
Sustancia Negra
/
Melaninas
/
Proteínas del Tejido Nervioso
Tipo de estudio:
Prognostic_studies
Límite:
Aged
/
Aged80
/
Humans
Idioma:
En
Revista:
Neurochem Int
Año:
2003
Tipo del documento:
Article
País de afiliación:
Italia