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Allele-specific RNA silencing of mutant ataxin-3 mediates neuroprotection in a rat model of Machado-Joseph disease.

Alves S, Nascimento-Ferreira I, Auregan G, Hassig R, Dufour N, Brouillet E, Pedroso de Lima MC, Hantraye P, Pereira de Almeida L, Déglon N - PLoS ONE (2008)

Bottom Line: Lentiviral-mediated silencing of mutant human ataxin-3 was demonstrated in vitro and in a rat model of MJD in vivo.The allele-specific silencing of ataxin-3 significantly decreased the severity of the neuropathological abnormalities associated with MJD.These data demonstrate that RNAi has potential for use in MJD treatment and constitute the first proof-of-principle for allele-specific silencing in the central nervous system.

View Article: PubMed Central - PubMed

Affiliation: Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal.

ABSTRACT
Recent studies have demonstrated that RNAi is a promising approach for treating autosomal dominant disorders. However, discrimination between wild-type and mutant transcripts is essential, to preserve wild-type expression and function. A single nucleotide polymorphism (SNP) is present in more than 70% of patients with Machado-Joseph disease (MJD). We investigated whether this SNP could be used to inactivate mutant ataxin-3 selectively. Lentiviral-mediated silencing of mutant human ataxin-3 was demonstrated in vitro and in a rat model of MJD in vivo. The allele-specific silencing of ataxin-3 significantly decreased the severity of the neuropathological abnormalities associated with MJD. These data demonstrate that RNAi has potential for use in MJD treatment and constitute the first proof-of-principle for allele-specific silencing in the central nervous system.

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Related in: MedlinePlus

Allele-specific silencing of mutant human ataxin-3 prevents neurodegeneration in the adult rat striatum.Coalescence of the internal capsule of the striatum is observed after co-infection with MUT ATX3 and shGFP (A, n = 4) or shAtaxWT (D, n = 8), at 2 months, on a bright-field photomicrograph, whereas no signs of striatal shrinkage are observed following co-infection with MUT ATX3 and the specific shAtaxMUT (G, n = 7) (left column). Neurodegeneration in rats co-infected with MUT ATX3 and shGFP (B) or shAtaxWT (E) is observed two months after injection on Fluorojade B-stained sections, but not in rats co-infected with MUT ATX3 and the selective shAtaxMUT (H) (middle column). Pycnotic nuclei are visible on cresyl violet-stained sections, suggesting cell injury and striatal degeneration after brain co-infection with MUT ATX3 and the control shGFP (C) or the non specific shAtaxWT (F), in adult rats at 2 months after injection. No such nuclei are observed on sections from rats co-infected with MUT ATX3 and the specific shAtaxMUT (I) (right column). All the pictures were taken around the injection site area and show representative immunohistochemical stainings that were reproducible among the different groups.
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pone-0003341-g009: Allele-specific silencing of mutant human ataxin-3 prevents neurodegeneration in the adult rat striatum.Coalescence of the internal capsule of the striatum is observed after co-infection with MUT ATX3 and shGFP (A, n = 4) or shAtaxWT (D, n = 8), at 2 months, on a bright-field photomicrograph, whereas no signs of striatal shrinkage are observed following co-infection with MUT ATX3 and the specific shAtaxMUT (G, n = 7) (left column). Neurodegeneration in rats co-infected with MUT ATX3 and shGFP (B) or shAtaxWT (E) is observed two months after injection on Fluorojade B-stained sections, but not in rats co-infected with MUT ATX3 and the selective shAtaxMUT (H) (middle column). Pycnotic nuclei are visible on cresyl violet-stained sections, suggesting cell injury and striatal degeneration after brain co-infection with MUT ATX3 and the control shGFP (C) or the non specific shAtaxWT (F), in adult rats at 2 months after injection. No such nuclei are observed on sections from rats co-infected with MUT ATX3 and the specific shAtaxMUT (I) (right column). All the pictures were taken around the injection site area and show representative immunohistochemical stainings that were reproducible among the different groups.

Mentions: Finally, the staining of degenerating neurons with fluorojade B (Figure 9B, E, H) and cresyl violet (Figure 9C, F, I) further demonstrated that the selective silencing of mutant ataxin-3 markedly decreased the number of degenerating neurons and atrophic nuclei, leading to typical striatum shrinkage (Fig. 9A, D, G).


Allele-specific RNA silencing of mutant ataxin-3 mediates neuroprotection in a rat model of Machado-Joseph disease.

Alves S, Nascimento-Ferreira I, Auregan G, Hassig R, Dufour N, Brouillet E, Pedroso de Lima MC, Hantraye P, Pereira de Almeida L, Déglon N - PLoS ONE (2008)

Allele-specific silencing of mutant human ataxin-3 prevents neurodegeneration in the adult rat striatum.Coalescence of the internal capsule of the striatum is observed after co-infection with MUT ATX3 and shGFP (A, n = 4) or shAtaxWT (D, n = 8), at 2 months, on a bright-field photomicrograph, whereas no signs of striatal shrinkage are observed following co-infection with MUT ATX3 and the specific shAtaxMUT (G, n = 7) (left column). Neurodegeneration in rats co-infected with MUT ATX3 and shGFP (B) or shAtaxWT (E) is observed two months after injection on Fluorojade B-stained sections, but not in rats co-infected with MUT ATX3 and the selective shAtaxMUT (H) (middle column). Pycnotic nuclei are visible on cresyl violet-stained sections, suggesting cell injury and striatal degeneration after brain co-infection with MUT ATX3 and the control shGFP (C) or the non specific shAtaxWT (F), in adult rats at 2 months after injection. No such nuclei are observed on sections from rats co-infected with MUT ATX3 and the specific shAtaxMUT (I) (right column). All the pictures were taken around the injection site area and show representative immunohistochemical stainings that were reproducible among the different groups.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2553199&req=5

pone-0003341-g009: Allele-specific silencing of mutant human ataxin-3 prevents neurodegeneration in the adult rat striatum.Coalescence of the internal capsule of the striatum is observed after co-infection with MUT ATX3 and shGFP (A, n = 4) or shAtaxWT (D, n = 8), at 2 months, on a bright-field photomicrograph, whereas no signs of striatal shrinkage are observed following co-infection with MUT ATX3 and the specific shAtaxMUT (G, n = 7) (left column). Neurodegeneration in rats co-infected with MUT ATX3 and shGFP (B) or shAtaxWT (E) is observed two months after injection on Fluorojade B-stained sections, but not in rats co-infected with MUT ATX3 and the selective shAtaxMUT (H) (middle column). Pycnotic nuclei are visible on cresyl violet-stained sections, suggesting cell injury and striatal degeneration after brain co-infection with MUT ATX3 and the control shGFP (C) or the non specific shAtaxWT (F), in adult rats at 2 months after injection. No such nuclei are observed on sections from rats co-infected with MUT ATX3 and the specific shAtaxMUT (I) (right column). All the pictures were taken around the injection site area and show representative immunohistochemical stainings that were reproducible among the different groups.
Mentions: Finally, the staining of degenerating neurons with fluorojade B (Figure 9B, E, H) and cresyl violet (Figure 9C, F, I) further demonstrated that the selective silencing of mutant ataxin-3 markedly decreased the number of degenerating neurons and atrophic nuclei, leading to typical striatum shrinkage (Fig. 9A, D, G).

Bottom Line: Lentiviral-mediated silencing of mutant human ataxin-3 was demonstrated in vitro and in a rat model of MJD in vivo.The allele-specific silencing of ataxin-3 significantly decreased the severity of the neuropathological abnormalities associated with MJD.These data demonstrate that RNAi has potential for use in MJD treatment and constitute the first proof-of-principle for allele-specific silencing in the central nervous system.

View Article: PubMed Central - PubMed

Affiliation: Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal.

ABSTRACT
Recent studies have demonstrated that RNAi is a promising approach for treating autosomal dominant disorders. However, discrimination between wild-type and mutant transcripts is essential, to preserve wild-type expression and function. A single nucleotide polymorphism (SNP) is present in more than 70% of patients with Machado-Joseph disease (MJD). We investigated whether this SNP could be used to inactivate mutant ataxin-3 selectively. Lentiviral-mediated silencing of mutant human ataxin-3 was demonstrated in vitro and in a rat model of MJD in vivo. The allele-specific silencing of ataxin-3 significantly decreased the severity of the neuropathological abnormalities associated with MJD. These data demonstrate that RNAi has potential for use in MJD treatment and constitute the first proof-of-principle for allele-specific silencing in the central nervous system.

Show MeSH
Related in: MedlinePlus