Homeostatic Fluctuations of a Tissue Surface

Area of Science:

• Biophysics
• Soft Matter Physics
• Cellular Dynamics

Background:

• Tissues exhibit complex surface dynamics driven by cellular processes like rearrangement, division, and death.
• Understanding these fluctuations is crucial for tissue development, regeneration, and disease modeling.

Purpose of the Study:

• To analyze the surface fluctuations of a tissue model incorporating cell division, death, and rearrangement.
• To characterize the fluctuation spectrum in a homeostatic state and explore its connections to other physical systems.
• To investigate the implications of out-of-equilibrium processes on tissue dynamics and response.

Main Methods:

• Modeling tissue surface dynamics with cell rearrangement, division, and death.
• Calculating the surface fluctuation spectrum in the homeostatic regime.
• Mapping the fluctuation spectrum to models of fluids, elastomers, and membranes.

Main Results:

• The fluctuation spectrum of the tissue surface in homeostasis is analogous to spectra of incompressible fluids, compressible Maxwell elastomers, and permeable membranes.
• Despite broken detailed balance due to out-of-equilibrium cell processes, a generalized fluctuation-response relation is satisfied.
• This work provides a framework for describing out-of-equilibrium fluctuations in thick epithelia.

Conclusions:

• Tissue surface fluctuations exhibit universal behaviors shared with diverse physical systems.
• The study establishes a foundation for understanding the dynamical response of tissues to external perturbations.
• This research opens avenues for further investigation into non-equilibrium biophysical phenomena.