Electrical stimulation induces calcium-dependent up-regulation of neuregulin-1? in dystrophic skeletal muscle cell lines

Juretic, N; Jorquera, G; Jaimovich E.; Riveros, N.; Caviedes P.

Keywords: muscle, differentiation, depolarization, development, expression, ion, protein, cell, gene, ryanodine, calcium, human, receptor, tissue, rna, article, kinase, factor, morpholino, skeletal, controlled, animal, dystrophy, c, study, 8, priority, nonhuman, journal, 2, Messenger, neu, electrostimulation, myotube, upregulation, dactinomycin, Duchenne, muscular, xestospongin, phenylchromone, utrophin


Duchenne muscular dystrophy (DMD) is a neuromuscular disease originated by reduced or no expression of dystrophin, a cytoskeletal protein that provides structural integrity to muscle fibres. A promising pharmacological treatment for DMD aims to increase the level of a structural dystrophin homolog called utrophin. Neuregulin-1 (NRG-1), a growth factor that potentiates myogenesis, induces utrophin expression in skeletal muscle cells. Microarray analysis of total gene expression allowed us to determine that neuregulin-1? (NRG-1?) is one of 150 differentially expressed genes in electrically stimulated (400 pulses, 1 ms, 45 Hz) dystrophic human skeletal muscle cells (RCDMD). We investigated the effect of depolarization, and the involvement of intracellular Ca 2+ and PKC isoforms on NRG-1? expression in dystrophic myotubes. Electrical stimulation of RCDMD increased NRG-1? mRNA and protein levels, and mRNA enhancement was abolished by actinomycin D. NRG-1? transcription was inhibited by BAPTA-AM, an intracellular Ca 2+ chelator, and by inhibitors of IP3-dependent slow Ca 2+ transients, like 2-APB, Ly 294002 and Xestospongin B. Ryanodine, a fast Ca 2+ signal inhibitor, had no effect on electrical stimulation-induced expression. BIM VI (general inhibitor of PKC isoforms) and Gö 6976 (specific inhibitor of Ca 2+-dependent PKC isoforms) abolished NRG-1? mRNA induction. Our results suggest that depolarization induced slow Ca 2+ signals stimulate NRG-1? transcription in RCDMD cells, and that Ca 2+-dependent PKC isoforms are involved in this process. Based on utrophin's ability to partially compensate dystrophin disfunction, knowledge on the mechanism involved on NRG-1 up-regulation could be important for new therapeutic strategies design. Copyright © 2012 S. Karger AG, Basel.

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Volumen: 29
Número: 5-6
Editorial: Karger
Fecha de publicación: 2012
Página de inicio: 919
Página final: 930
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-84861395927&partnerID=q2rCbXpz