Scientific article

Calcium sources used by post-natal human myoblasts during initial differentiation

Published inJournal of cellular physiology, vol. 208, no. 2, p. 435-445
Publication date2006

Increases in cytoplasmic Ca(2+) are crucial for inducing the initial steps of myoblast differentiation that ultimately lead to fusion; yet the mechanisms that produce this elevated Ca(2+) have not been fully resolved. For example, it is still unclear whether the increase comes exclusively from membrane Ca(2+) influx or also from Ca(2+) release from internal stores. To address this, we investigated early differentiation of myoblast clones each derived from single post-natal human satellite cells. Initial differentiation was assayed by immunostaining myonuclei for the transcription factor MEF2. When Ca(2+) influx was eliminated by using low external Ca(2+) media, we found that approximately half the clones could still differentiate. Of the clones that required influx of external Ca(2+), most clones used T-type Ca(2+) channels, but others used store-operated channels as influx-generating mechanisms. On the other hand, clones that differentiated in low external Ca(2+) relied on Ca(2+) release from internal stores through IP(3) receptors. Interestingly, by following clones over time, we observed that some switched their preferred Ca(2+) source: clones that initially used calcium release from internal stores to differentiate later required Ca(2+) influx and inversely. In conclusion, we show that human myoblasts can use three alternative mechanisms to increase cytoplasmic Ca(2+) at the onset of the differentiation process: influx through T-types Ca(2+) channels, influx through store operated channels and release from internal stores through IP(3) receptors. In addition, we suggest that, probably because Ca(2+) elevation is essential during initial differentiation, myoblasts may be able to select between these alternate Ca(2+) pathways.

  • Calcium/ metabolism
  • Calcium Channels/metabolism
  • Cell Culture Techniques
  • Cell Differentiation
  • Cells, Cultured
  • Child
  • Child, Preschool
  • Clone Cells
  • Humans
  • Immunohistochemistry
  • Infant
  • Models, Biological
  • Myoblasts/ cytology/drug effects/ physiology
  • Thapsigargin/pharmacology
Citation (ISO format)
ARNAUDEAU, Serge et al. Calcium sources used by post-natal human myoblasts during initial differentiation. In: Journal of cellular physiology, 2006, vol. 208, n° 2, p. 435–445. doi: 10.1002/jcp.20679
Main files (1)
ISSN of the journal0021-9541

Technical informations

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