A coarse-grained red blood cell membrane model to study stomatocyte-discocyte-echinocyte morphologies

Area of Science:

• Biophysics
• Cellular mechanics
• Computational biology

Background:

• Red blood cell (RBC) shape is critical for function and survival.
• Existing models struggle to fully capture the stomatocyte-discocyte-echinocyte (SDE) transformation sequence.
• Understanding RBC membrane mechanics is vital for diagnosing and treating related diseases.

Purpose of the Study:

• To develop an improved coarse-grained (CG) RBC membrane model.
• To accurately predict the complete stomatocyte-discocyte-echinocyte (SDE) transformation sequence.
• To investigate factors influencing RBC shape and deformability.

Main Methods:

• Development of a CG-RBC membrane model based on the bilayer coupling model (BCM).
• Incorporation of new constraints, including total membrane curvature, alongside traditional ones (surface area, volume, leaflet area difference).
• Quantitative comparison of model predictions with 3D confocal microscopy imaging of RBCs.

Main Results:

• The CG-RBC model accurately predicts RBC shapes, including the SDE transformation sequence.
• The model successfully integrates lipid bilayer bending resistance and cytoskeletal shear resistance.
• Quantitative validation against experimental data demonstrates the model's predictive power.

Conclusions:

• The validated CG-RBC model provides a robust tool for studying RBC shape dynamics.
• The model can predict SDE shape behavior under various conditions, including in vitro storage and microcirculation.
• This work offers insights into RBC deformability and cytoskeletal states during shape transformations.