Expression of the dystrophin isoform Dp116 preserves functional muscle mass and extends lifespan without preventing dystrophy in severely dystrophic mice.
Hum Mol Genet
; 20(24): 4978-90, 2011 Dec 15.
Article
em En
| MEDLINE
| ID: mdl-21949353
ABSTRACT
Dp116 is a non-muscle isoform of dystrophin that assembles the dystrophin-glycoprotein complex (DGC), but lacks actin-binding domains. To examine the functional role of the DGC, we expressed the Dp116 transgene in mice lacking both dystrophin and utrophin (mdxutrn(-/-)). Unexpectedly, expression of Dp116 prevented the most severe aspects of the mdxutrn(-/-) phenotype. Dp116mdxutrn(-/-) transgenic mice had dramatic improvements in growth, mobility and lifespan compared with controls. This was associated with increased muscle mass and force generating capacity of limb muscles, although myofiber size and specific force were unchanged. Conversely, Dp116 had no effect on dystrophic injury as determined by muscle histopathology and serum creatine kinase levels. Dp116 also failed to restore normal fiber-type distribution or the post-synaptic architecture of the neuromuscular junction. These data demonstrate that the DGC is critical for growth and maintenance of muscle mass, a function that is independent of the ability to prevent dystrophic pathophysiology. Likewise, this is the first demonstration in skeletal muscle of a positive functional role for a dystrophin protein that lacks actin-binding domains. We conclude that both mechanical and non-mechanical functions of dystrophin are important for its role in skeletal muscle.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Distrofina
/
Músculo Esquelético
/
Longevidade
/
Distrofia Muscular Animal
Limite:
Animals
Idioma:
En
Revista:
Hum Mol Genet
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA MEDICA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos