SPEG-deficient skeletal muscles exhibit abnormal triad and defective calcium handling.
Hum Mol Genet
; 27(9): 1608-1617, 2018 05 01.
Article
em En
| MEDLINE
| ID: mdl-29474540
ABSTRACT
Centronuclear myopathies (CNM) are a subtype of congenital myopathies (CM) characterized by skeletal muscle weakness and an increase in the number of central myonuclei. We have previously identified three CNM probands, two with associated dilated cardiomyopathy, carrying striated preferentially expressed gene (SPEG) mutations. Currently, the role of SPEG in skeletal muscle function is unclear as constitutive SPEG-deficient mice developed severe dilated cardiomyopathy and died in utero. We have generated a conditional Speg-KO mouse model and excised Speg by crosses with striated muscle-specific cre-expressing mice (MCK-Cre). The resulting litters had a delay in Speg excision consistent with cre expression starting in early postnatal life and, therefore, an extended lifespan up to a few months. KO mice were significantly smaller and weaker than their littermate-matched controls. Histopathological skeletal muscle analysis revealed smaller myofibers, marked fiber-size variability, and poor integrity and low number of triads. Further, SPEG-deficient muscle fibers were weaker by physiological and in vitro studies and exhibited abnormal Ca2+ handling and excitation-contraction (E-C) coupling. Overall, SPEG deficiency in skeletal muscle is associated with fewer and abnormal triads, and defective calcium handling and excitation-contraction coupling, suggesting that therapies targeting calcium signaling may be beneficial in such patients.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Quinase de Cadeia Leve de Miosina
/
Cálcio
/
Músculo Esquelético
/
Miopatias Congênitas Estruturais
/
Proteínas Musculares
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Hum Mol Genet
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA MEDICA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos