Properties and role of voltage-dependent calcium channels during mouse skeletal muscle differentiation.
Skeletal muscle differentiation depends on calcium ions, but it is yet unclear whether calcium entry through voltage-dependent calcium channels (VDCCs) contributes to the myoblast fusion process. In this study, we investigate whether calcium influx through functional T-type VDCCs precedes and affects mouse satellite cell fusion. We report here on the properties and the role of the VDCCs expressed in differentiating mouse muscular cells using both the C2C12 cell line and primary cultures of satellite cells. We present electrophysiological and biochemical evidence demonstrating that T-type and L-type VDCCs are not present in C2C12 and primary cultures of mouse satellite cells prior to the fusion stage. Although mRNA for the T-type Ca(V)3.2 subunit was detected in differentiated C2C12 cells, no T-type calcium currents could be recorded, while both T-type and L-type calcium currents were detected after the fusion process in primary cultures. In addition, chronic application of 30 microM nickel, known to inhibit T-type Ca(V)3.2 channels, did not alter the fusion of C2C12 cells and mouse satellite cells in primary culture. Overall, the data indicate that, unlike in humans, Ca(V)3.2 T-type calcium channels play no role in mouse satellite cell fusion.
Institut de Génomique Fonctionnelle, CNRS UMR5203, INSERM U661, Universités de Montpellier I & II, 141, rue de la Cardonille, 34094 Montpellier cedex 05, France.
Isabelle
I
Bidaud
Arnaud
A
Monteil
Joël
J
Nargeot
Philippe
P
Lory
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020747:Calcium Channels, T-Type / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D009532:Nickel / Q000494:pharmacology; D012038:Regeneration / Q000502:physiology; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
C504883:Cacna1h protein, mouse; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D020747:Calcium Channels, T-Type; D009532:Nickel