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Updated: Jul 15, 2026
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Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement
Published on: July 26, 2017
Endoplasmic reticulum stress increases myofiber formation in vitro
Keiko Nakanishi1, Naoshi Dohmae, Nobuhiro Morishima
1The Biomolecular Characterization Team, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Summary
Endoplasmic reticulum (ER) stress enhances muscle cell (myoblast) differentiation by selectively eliminating vulnerable cells. Surviving myoblasts form robust myofibers, suggesting ER stress aids muscle repair therapies.
Area of Science:
- Cell Biology
- Muscle Physiology
- Biochemistry
Background:
- Myoblast differentiation is crucial for muscle repair and involves fusion and myofiber formation.
- Endoplasmic reticulum (ER) stress signaling has been observed during myogenesis in vivo.
- ER stress inhibition in cell culture blocked apoptosis and myoblast differentiation.
Purpose of the Study:
- To investigate the role of ER stress inducers during myoblast differentiation.
- To determine the effect of ER stress on apoptosis and myofiber formation in myoblasts.
- To explore the potential therapeutic implications of ER stress in muscle regeneration.
Main Methods:
- Cultured myoblasts were exposed to ER stress inducers (tunicamycin, thapsigargin) during the proliferation-to-differentiation transition.
- Doses were chosen to induce 40-50% apoptosis in myoblast cultures.
- Apoptosis rates, cell survival, and myofiber formation were assessed.
Main Results:
- Increased ER stress significantly enhanced differentiation-associated apoptosis in myoblasts.
- Surviving myoblasts exhibited increased resistance to apoptosis.
- These surviving cells efficiently differentiated into contracting myofibers, a rare outcome in standard culture models.
Conclusions:
- ER stress selectively eliminates vulnerable myoblasts, promoting the survival and differentiation of more resistant cells.
- ER stress positively influences myofiber formation, potentially mimicking in vivo signaling pathways.
- These findings offer insights for developing therapies to enhance muscle regeneration and myofiber formation.
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