A simple mechanochemical model for calcium signalling in embryonic epithelial cells

Area of Science:

• Developmental Biology
• Cellular Mechanics
• Biophysics

Background:

• Calcium signalling is crucial for cellular communication and information propagation.
• The interplay between calcium signalling and mechanical forces is vital for embryonic development but remains poorly understood.
• Embryonic cells exhibit calcium-induced contractions, suggesting a two-way mechanochemical feedback mechanism.

Purpose of the Study:

• To analyze experimental data supporting mechanochemical coupling during apical constriction.
• To propose a novel mechanochemical model integrating validated calcium dynamics with cell mechanics.
• To investigate the role of stretch-activated calcium channels in this feedback loop.

Main Methods:

• Analysis of experimental data on apical constriction.
• Development of a new mechanochemical model using ordinary differential equations.
• Incorporation of experimentally validated calcium dynamics and a Hill function for calcium-induced stress.
• Semi-analytical analysis of the model's bifurcation structure.

Main Results:

• The model supports mechanochemical coupling during apical constriction.
• Calcium signalling exhibits relaxation oscillations within a specific parameter range.
• Increased 'stretch activation' strength reduces and eventually eliminates oscillations, mirroring experimental observations.
• Increased 'stretch activation' decreases oscillation amplitude and increases frequency.
• Oscillations are identified within a specific range of cytosolic mechanical responsiveness.

Conclusions:

• The proposed model provides a framework for understanding calcium-mechanical feedback in embryogenesis.
• The loss of calcium oscillations correlates with embryo abnormalities, highlighting the model's relevance.
• This research elucidates the critical coupling between chemical and mechanical signalling in early development.