A numerical method to predict the membrane tension distribution of spreading cells based on the reconstruction of focal adhesions

Changes in membrane tension significantly affect the physiological functions of cells in various ways. However, directly measuring the spatial distribution of membrane tension remains an ongoing issue. In this study, an algorithm is proposed to determine the membrane tension inversely by executing a particle-based method and searching for the minimum deformation energy based on the cell images and focal adhesions. A standard spreading cell model is established using 3D reconstructions with images from structured illumination microscopy as the reference cell shape. The membrane tension distribution, forces across focal adhesions, and profile of the spread cell are obtained using this method, until the cell deformation energy function optimization converges. Qualitative and quantitative comparisons with previous experimental results validated the reliability of this method. The results show that in the standard spreading cell model, the membrane tension decreases from the bottom to the top of the membrane. This method can be applied to predict the membrane tension distribution of cells freely spreading into different shapes, which could improve the quantitative analysis of cellular membrane tension in various studies for cell mechanics.