Truncated dystrophin ameliorates the dystrophic phenotype of mdx mice by reducing sarcolipin-mediated SERCA inhibition.
Biochem Biophys Res Commun
; 505(1): 51-59, 2018 10 20.
Article
em En
| MEDLINE
| ID: mdl-30236982
ABSTRACT
Duchenne muscular dystrophy (DMD) and the less severe Becker muscular dystrophy (BMD) are due to mutations in the DMD gene. Previous reports show that in-frame deletion of exons 45-55 produces an internally shorted, but functional, dystrophin protein resulting in a very mild BMD phenotype. In order to elucidate the molecular mechanism leading to this phenotype, we generated exon 45-55 deleted dystrophin transgenic/mdx (Tg/mdx) mice. Muscular function of Tg/mdx mice was restored close to that of wild type (WT) mice but the localization of the neuronal type of nitric oxide synthase was changed from the sarcolemma to the cytosol. This led to hyper-nitrosylation of the ryanodine receptor 1 causing increased Ca2+ release from the sarcoplasmic reticulum. On the other hand, Ca2+ reuptake by the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) was restored to the level of WT mice, suggesting that the Ca2+ dysregulation had been compensated by SERCA activation. In line with this, expression of sarcolipin (SLN), a SERCA-inhibitory peptide, was upregulated in mdx mice, but strongly reduced in Tg/mdx mice. Furthermore, knockdown of SLN ameliorated the cytosolic Ca2+ homeostasis and the dystrophic phenotype in mdx mice. These findings suggest that SLN may be a novel target for DMD therapy.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Proteolipídeos
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Distrofina
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Distrofia Muscular de Duchenne
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ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático
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Proteínas Musculares
Limite:
Animals
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Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Japão