NF-kappa B activation by depolarization of skeletal muscle cells depends on ryanodine and IP3 receptor-mediated calcium signals

Valdes, JA; Hidalgo J.; Galaz, JL; Puentes, N; Silva M.; Jaimovich E.; Carrasco MA

Abstract

Depolarization of skeletal muscle cells by either high external K + or repetitive extracellular field potential pulses induces calcium release from internal stores. The two components of this release are mediated by either ryanodine receptors or inositol 1,4,5-trisphosphate (IP3) receptors and show differences in kinetics, amplitude, and subcellular localization. We have reported that the transcriptional regulators including ERKs, cAMP/Ca2+-response element binding protein, c-fos, c-jun, and egr-1 are activated by K+-induced depolarization and that their activation requires IP3-dependent calcium release. We presently describe the activation of the nuclear transcription factor NF-κB in response to depolarization by either high K+ (chronic) or electrical pulses (fluctuating). Calcium transients of relative short duration activate an NF-κB reporter gene to an intermediate level, whereas long-lasting calcium increases obtained by prolonged electrical stimulation protocols of various frequencies induce maximal activation of NF-κB. This activation is independent of extracellular calcium, whereas calcium release mediated by either ryanodine or IP3 receptors contribute in all conditions tested. NF-κB activation is mediated by IκBα degradation and p65 translocation to the nucleus. Partial blockade by N-acetyl-L-cysteine, a general antioxidant, suggests the participation of reactive oxygen species. Calcium-dependent signaling pathways such as those linked to calcineurin and PKC also contribute to NF-κB activation by depolarization, as assessed by blockade through pharmacological agents. These results suggest that NF-κB activation in skeletal muscle cells is linked to membrane depolarization and depends on the duration of elevated intracellular calcium. It can be regulated by sequential activation of calcium release mediated by the ryanodine and by IP3 receptors. Copyright © 2007 the American Physiological Society.

Más información

Título según WOS: NF-kappa B activation by depolarization of skeletal muscle cells depends on ryanodine and IP3 receptor-mediated calcium signals
Título según SCOPUS: NF-?B activation by depolarization of skeletal muscle cells depends on ryanodine and IP3 receptor-mediated calcium signals
Título de la Revista: AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
Volumen: 292
Número: 5
Editorial: AMER PHYSIOLOGICAL SOC
Fecha de publicación: 2007
Página de inicio: C1960
Página final: C1970
Idioma: English
URL: http://ajpcell.physiology.org/cgi/doi/10.1152/ajpcell.00320.2006
DOI:

10.1152/ajpcell.00320.2006

Notas: ISI, SCOPUS