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Parkin deficiency delays motor decline and disease manifestation in a mouse model of synucleinopathy.

Fournier M, Vitte J, Garrigue J, Langui D, Dullin JP, Saurini F, Hanoun N, Perez-Diaz F, Cornilleau F, Joubert C, Ardila-Osorio H, Traver S, Duchateau R, Goujet-Zalc C, Paleologou K, Lashuel HA, Haass C, Duyckaerts C, Cohen-Salmon C, Kahle PJ, Hamon M, Brice A, Corti O - PLoS ONE (2009)

Bottom Line: The symptoms were accompanied by the deposition of P(S129)-alpha-synuclein but not P(S87)-alpha-synuclein in neuronal cell bodies and neuritic processes throughout the brainstem and the spinal cord; activation of caspase 9 was observed in 5% of the P(S129)-alpha-synuclein-positive neurons.As in Lewy bodies, ubiquitin-immunoreactivity, albeit less abundant, was invariably co-localized with P(S129)-alpha-synuclein.However, the proportion of P(S129)-alpha-synuclein-immunoreactive neuronal cell bodies and neurites co-stained for ubiquitin was lower in the absence than in the presence of Parkin, suggesting less advanced synucleinopathy.

View Article: PubMed Central - PubMed

Affiliation: Université Pierre et Marie Curie-Paris 6, CRICM (Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière), UMR-S975, Paris, France.

ABSTRACT
In synucleinopathies, including Parkinson's disease, partially ubiquitylated alpha-synuclein species phosphorylated on serine 129 (P(S129)-alpha-synuclein) accumulate abnormally. Parkin, an ubiquitin-protein ligase that is dysfunctional in autosomal recessive parkinsonism, protects against alpha-synuclein-mediated toxicity in various models.We analyzed the effects of Parkin deficiency in a mouse model of synucleinopathy to explore the possibility that Parkin and alpha-synuclein act in the same biochemical pathway. Whether or not Parkin was present, these mice developed an age-dependent neurodegenerative disorder preceded by a progressive decline in performance in tasks predictive of sensorimotor dysfunction. The symptoms were accompanied by the deposition of P(S129)-alpha-synuclein but not P(S87)-alpha-synuclein in neuronal cell bodies and neuritic processes throughout the brainstem and the spinal cord; activation of caspase 9 was observed in 5% of the P(S129)-alpha-synuclein-positive neurons. As in Lewy bodies, ubiquitin-immunoreactivity, albeit less abundant, was invariably co-localized with P(S129)-alpha-synuclein. During late disease stages, the disease-specific neuropathological features revealed by ubiquitin- and P(S129)-alpha-synuclein-specific antibodies were similar in mice with or without Parkin. However, the proportion of P(S129)-alpha-synuclein-immunoreactive neuronal cell bodies and neurites co-stained for ubiquitin was lower in the absence than in the presence of Parkin, suggesting less advanced synucleinopathy. Moreover, sensorimotor impairment and manifestation of the neurodegenerative phenotype due to overproduction of human alpha-synuclein were significantly delayed in Parkin-deficient mice.These findings raise the possibility that effective compensatory mechanisms modulate the phenotypic expression of disease in parkin-related parkinsonism.

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Generation of mice overproducing human α-synuclein in a Parkin-deficient background.(A) Breeding strategy. Parental homozygous parkin −/− and hA30Pα-syn +/+ mice were intercrossed. The breeding of the double heterozygous mice (F1) led to the generation of littermates of the nine expected genotypes, four of which, highlighted by the surrounding frames, were used for subsequent analyses. (B) Representative western blot analysis of brain extracts of 17 months-old mice showing the expression of the endogenous parkin gene and of the hA30Pα-syn transgene, normalized to actin levels.
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pone-0006629-g001: Generation of mice overproducing human α-synuclein in a Parkin-deficient background.(A) Breeding strategy. Parental homozygous parkin −/− and hA30Pα-syn +/+ mice were intercrossed. The breeding of the double heterozygous mice (F1) led to the generation of littermates of the nine expected genotypes, four of which, highlighted by the surrounding frames, were used for subsequent analyses. (B) Representative western blot analysis of brain extracts of 17 months-old mice showing the expression of the endogenous parkin gene and of the hA30Pα-syn transgene, normalized to actin levels.

Mentions: A mouse model transgenic for human A30P α-synuclein and deficient for Parkin was generated through a breeding strategy aimed at minimising strain effects, using two previously established mouse lines: parkin exon 3-deleted mice (parkin −/−) [36] and hA30Pα-syn mice [14], [37] (Figure 1A). Homozygous parkin −/− mice were bred with homozygous hA30Pα-syn mice. The double heterozygous generation was intercrossed to generate littermates of the nine expected genotypes in proportions consistent with Mendelian inheritance. Double homozygous mice and their age-matched littermates of wild-type or single homozygous, parental genotypes were kept for subsequent analyses. Appropriate expression of the endogenous parkin gene and the α-synuclein transgene were confirmed by western blotting with whole brain extracts (Figure 1B).


Parkin deficiency delays motor decline and disease manifestation in a mouse model of synucleinopathy.

Fournier M, Vitte J, Garrigue J, Langui D, Dullin JP, Saurini F, Hanoun N, Perez-Diaz F, Cornilleau F, Joubert C, Ardila-Osorio H, Traver S, Duchateau R, Goujet-Zalc C, Paleologou K, Lashuel HA, Haass C, Duyckaerts C, Cohen-Salmon C, Kahle PJ, Hamon M, Brice A, Corti O - PLoS ONE (2009)

Generation of mice overproducing human α-synuclein in a Parkin-deficient background.(A) Breeding strategy. Parental homozygous parkin −/− and hA30Pα-syn +/+ mice were intercrossed. The breeding of the double heterozygous mice (F1) led to the generation of littermates of the nine expected genotypes, four of which, highlighted by the surrounding frames, were used for subsequent analyses. (B) Representative western blot analysis of brain extracts of 17 months-old mice showing the expression of the endogenous parkin gene and of the hA30Pα-syn transgene, normalized to actin levels.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2722082&req=5

pone-0006629-g001: Generation of mice overproducing human α-synuclein in a Parkin-deficient background.(A) Breeding strategy. Parental homozygous parkin −/− and hA30Pα-syn +/+ mice were intercrossed. The breeding of the double heterozygous mice (F1) led to the generation of littermates of the nine expected genotypes, four of which, highlighted by the surrounding frames, were used for subsequent analyses. (B) Representative western blot analysis of brain extracts of 17 months-old mice showing the expression of the endogenous parkin gene and of the hA30Pα-syn transgene, normalized to actin levels.
Mentions: A mouse model transgenic for human A30P α-synuclein and deficient for Parkin was generated through a breeding strategy aimed at minimising strain effects, using two previously established mouse lines: parkin exon 3-deleted mice (parkin −/−) [36] and hA30Pα-syn mice [14], [37] (Figure 1A). Homozygous parkin −/− mice were bred with homozygous hA30Pα-syn mice. The double heterozygous generation was intercrossed to generate littermates of the nine expected genotypes in proportions consistent with Mendelian inheritance. Double homozygous mice and their age-matched littermates of wild-type or single homozygous, parental genotypes were kept for subsequent analyses. Appropriate expression of the endogenous parkin gene and the α-synuclein transgene were confirmed by western blotting with whole brain extracts (Figure 1B).

Bottom Line: The symptoms were accompanied by the deposition of P(S129)-alpha-synuclein but not P(S87)-alpha-synuclein in neuronal cell bodies and neuritic processes throughout the brainstem and the spinal cord; activation of caspase 9 was observed in 5% of the P(S129)-alpha-synuclein-positive neurons.As in Lewy bodies, ubiquitin-immunoreactivity, albeit less abundant, was invariably co-localized with P(S129)-alpha-synuclein.However, the proportion of P(S129)-alpha-synuclein-immunoreactive neuronal cell bodies and neurites co-stained for ubiquitin was lower in the absence than in the presence of Parkin, suggesting less advanced synucleinopathy.

View Article: PubMed Central - PubMed

Affiliation: Université Pierre et Marie Curie-Paris 6, CRICM (Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière), UMR-S975, Paris, France.

ABSTRACT
In synucleinopathies, including Parkinson's disease, partially ubiquitylated alpha-synuclein species phosphorylated on serine 129 (P(S129)-alpha-synuclein) accumulate abnormally. Parkin, an ubiquitin-protein ligase that is dysfunctional in autosomal recessive parkinsonism, protects against alpha-synuclein-mediated toxicity in various models.We analyzed the effects of Parkin deficiency in a mouse model of synucleinopathy to explore the possibility that Parkin and alpha-synuclein act in the same biochemical pathway. Whether or not Parkin was present, these mice developed an age-dependent neurodegenerative disorder preceded by a progressive decline in performance in tasks predictive of sensorimotor dysfunction. The symptoms were accompanied by the deposition of P(S129)-alpha-synuclein but not P(S87)-alpha-synuclein in neuronal cell bodies and neuritic processes throughout the brainstem and the spinal cord; activation of caspase 9 was observed in 5% of the P(S129)-alpha-synuclein-positive neurons. As in Lewy bodies, ubiquitin-immunoreactivity, albeit less abundant, was invariably co-localized with P(S129)-alpha-synuclein. During late disease stages, the disease-specific neuropathological features revealed by ubiquitin- and P(S129)-alpha-synuclein-specific antibodies were similar in mice with or without Parkin. However, the proportion of P(S129)-alpha-synuclein-immunoreactive neuronal cell bodies and neurites co-stained for ubiquitin was lower in the absence than in the presence of Parkin, suggesting less advanced synucleinopathy. Moreover, sensorimotor impairment and manifestation of the neurodegenerative phenotype due to overproduction of human alpha-synuclein were significantly delayed in Parkin-deficient mice.These findings raise the possibility that effective compensatory mechanisms modulate the phenotypic expression of disease in parkin-related parkinsonism.

Show MeSH
Related in: MedlinePlus