Myofibers deficient in connexins 43 and 45 expression protect mice from skeletal muscle and systemic dysfunction promoted by a dysferlin mutation

Copyright © 2020 Elsevier B.V. All rights reserved..

Dysferlinopathy is a genetic human disease caused by mutations in the gene that encodes the dysferlin protein (DYSF). Dysferlin is believed to play a relevant role in cell membrane repair. However, in dysferlin-deficient (blAJ) mice (a model of dysferlinopathies) the recovery of the membrane resealing function by means of the expression of a mini-dysferlin does not arrest progressive muscular damage, suggesting the participation of other unknown pathogenic mechanisms. Here, we show that proteins called connexins 39, 43 and 45 (Cx39, Cx43 and Cx45, respectively) are expressed by blAJ myofibers and form functional hemichannels (Cx HCs) in the sarcolemma. At rest, Cx HCs increased the sarcolemma permeability to small molecules and the intracellular Ca2+ signal. In addition, skeletal muscles of blAJ mice showed lipid accumulation and lack of dysferlin immunoreactivity. As sign of extensive damage and atrophy, muscles of blAJ mice presented elevated numbers of myofibers with internal nuclei, increased number of myofibers with reduced cross-sectional area and elevated creatine kinase activity in serum. In agreement with the extense muscle damage, mice also showed significantly low motor performance. We generated blAJ mice with myofibers deficient in Cx43 and Cx45 expression and found that all above muscle and systemic alterations were absent, indicating that these two Cxs play a critical role in a novel pathogenic mechanism of dysfernolophaties, which is discussed herein. Therefore, Cx HCs could constitute an attractive target for pharmacologic treatment of dyferlinopathies.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:1866

Enthalten in:

Biochimica et biophysica acta. Molecular basis of disease - 1866(2020), 8 vom: 01. Aug., Seite 165800

Sprache:

Englisch

Beteiligte Personen:

Fernández, Gabriela [VerfasserIn]
Arias-Bravo, Guisselle [VerfasserIn]
Bevilacqua, Jorge A [VerfasserIn]
Castillo-Ruiz, Mario [VerfasserIn]
Caviedes, Pablo [VerfasserIn]
Sáez, Juan C [VerfasserIn]
Cea, Luis A [VerfasserIn]

Links:

Volltext

Themen:

Calcium
Calcium ion
Connexin 39 protein, mouse
Connexin 43
Connexin 45
Connexins
Creatine Kinase
Dysf protein, mouse
Dysferlin
EC 2.7.3.2
Fat infiltration
GJA1 protein, mouse
Journal Article
Membrane permeability
Muscular dystrophy
Muscular performance
Research Support, Non-U.S. Gov't
SY7Q814VUP

Anmerkungen:

Date Completed 04.01.2021

Date Revised 04.01.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.bbadis.2020.165800

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM30890236X