Adaptive flexibility of cells through nonequilibrium entropy production

Area of Science:

• Cell Biology
• Biophysics
• Theoretical Biology

Background:

• Cellular adaptation to environmental changes involves dynamic remodeling of subcellular structures, particularly periodic actomyosin assemblies.
• Muscle cells have ordered sarcomeres for stable force generation, while nonmuscle cells have variable sarcomere-like units for adaptation.
• The functional significance of this structural variability in cytoskeletal adaptation is not fully understood within a unified framework.

Purpose of the Study:

• To propose a conceptual model grounded in nonequilibrium physics for a unified perspective on cytoskeletal adaptation variability.
• To investigate the role of structural randomness in cytoskeletal remodeling and adaptive cellular behavior.

Main Methods:

• Developed a conceptual model based on nonequilibrium physics.
• Quantified structural randomness using Shannon entropy to evaluate the effective binding strength of contractile units.
• Analyzed the relationship between structural disorder, binding energy, and cytoskeletal remodeling.

Main Results:

• Increased entropy (randomness) in nonmuscle cell assemblies lowers the energy barrier for cytoskeletal remodeling, facilitating adaptation.
• Ordered muscle cell sarcomeres exhibit higher binding energies, stabilizing configurations for sustained force generation.
• Structural disorder, contrary to common perception, can drive cytoskeletal remodeling and adaptive cellular behavior.

Conclusions:

• Structural randomness is a key factor in cytoskeletal adaptability across diverse cell types.
• A unified theoretical framework integrating structural randomness and nonequilibrium physics explains cytoskeletal adaptation.
• This framework provides insights into how cells balance stability and flexibility in response to environmental cues.