Cross talk between matrix elasticity and mechanical force regulates myoblast traction dynamics

Area of Science:

• Cellular mechanobiology
• Biophysics
• Tissue engineering

Background:

• Cellular processes are influenced by nanomechanical forces and microenvironment properties.
• Few studies have investigated the combined effects of these factors.

Purpose of the Study:

• To investigate how muscle precursor cells respond to simultaneous nanomechanical stimulation and varying substrate stiffness.
• To understand the role of substrate elasticity in cellular mechanotransduction.

Main Methods:

• Simultaneous atomic force microscopy and traction force microscopy were used.
• Muscle precursor cells (myoblasts) were cultured on hydrogel substrates with tunable elastic moduli (~16-89 kPa).
• Cells were subjected to localized 10 nN nanomechanical force stimulation.

Main Results:

• Myoblasts exhibited a rapid, transient increase in traction upon nanomechanical stimulation.
• This traction response was observed only on substrates mimicking the elasticity of working muscle tissue (~64-89 kPa).
• The response was dependent on rho-kinase and myosin-II activity and occurred within 30-60 seconds.

Conclusions:

• Cells can integrate nanoscale information, including nanomechanical forces and substrate mechanics, during mechanotransduction.
• Substrate elasticity plays a critical role in mediating cellular responses to external mechanical stimuli.
• These findings contribute to understanding the physiology of muscle precursor cells and tissue development.