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Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement
10:45

Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement

Published on: July 26, 2017

T-type alpha 1H Ca2+ channels are involved in Ca2+ signaling during terminal differentiation (fusion) of human

P Bijlenga1, J H Liu, E Espinos

  • 1Département de Physiologie, Centre Médical Universitaire, and Division de Recherche Clinique Neuro-Musculaire, Hôpital Cantonal Universitaire, CH-1211 Geneva 4, Switzerland.

Proceedings of the National Academy of Sciences of the United States of America
|June 22, 2000
PubMed

Insights

T-type calcium channels (T-channels) are crucial for human myoblast fusion. Blocking these channels prevents the necessary calcium increase and inhibits cell differentiation, highlighting their role in muscle development.

Area of Science:

  • Cellular Biology
  • Muscle Physiology
  • Ion Channel Function

Background:

  • Human myoblast terminal differentiation is a complex process involving significant cellular changes.
  • Calcium signaling plays a critical role in regulating various cellular events, including differentiation and fusion.

Purpose of the Study:

  • To investigate the specific mechanisms of calcium (Ca2+) signaling during human myoblast terminal differentiation.
  • To identify the types of calcium channels involved and their role in the fusion process.

Main Methods:

  • Utilized human myoblast cell cultures for experimental studies.
  • Employed pharmacological inhibitors (amiloride, Ni2+) and antisense oligonucleotides to study T-type calcium channel function.
  • Measured intracellular calcium concentration ([Ca2+]i) and membrane potential.

Main Results:

  • T-type calcium channels (T-channels) are expressed in myoblasts preceding fusion.
  • Inhibition of T-channels by amiloride or Ni2+ suppressed myoblast fusion and prevented the typical increase in intracellular calcium.
  • Antisense oligonucleotides confirmed that alpha1H subunits form functional T-channels.
  • At hyperpolarized potentials, T-channels allow a window current that elevates intracellular calcium, which is essential for fusion.

Conclusions:

  • The calcium signal necessary for myoblast fusion is generated when the resting membrane potential enters the T-channel window.
  • This mechanism, involving T-channels and membrane hyperpolarization, may be relevant for differentiation in other cell types.

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