In vitro exercise model using contractile human and mouse hybrid myotubes

Area of Science:

• Muscle physiology
• Cell biology
• Biotechnology

Background:

• Cultured human myotubes show limited contractile responses to electric pulse stimulation (EPS), hindering studies on muscle activity.
• Investigating cellular responses to muscle contraction, such as myokine secretion, requires robust in vitro models.

Purpose of the Study:

• To develop an improved in vitro exercise model using hybrid myotubes to enhance human myotube contractility and myokine secretion.
• To enable species-specific analysis of gene expression and myokine release from human and mouse cells within hybrid myotubes.

Main Methods:

• Creation of hybrid myotubes by fusing human myoblasts with murine C2C12 myoblasts.
• Application of electric pulse stimulation (EPS) to induce contractile activity in hybrid myotubes.
• Species-specific analysis using RT-PCR and BioPlex assay to quantify gene expression and myokine secretion.

Main Results:

• Hybrid myotubes exhibited vigorous contractile activity in response to EPS.
• Significant increases in human myokine secretions (interleukins, CXC/CC chemokines, IFN-γ) were observed following EPS.
• The hybrid model effectively overcame limitations of human myotube contractility.

Conclusions:

• Hybrid myotubes composed of human and C2C12 myoblasts provide a robust platform for studying muscle contraction and cellular responses.
• This enhanced in vitro exercise model facilitates the investigation of human myokine secretion and cellular signaling pathways.
• The approach expands the utility of in vitro models for muscle research.