Cell Chiral Orientation Enhanced by Intercellular Alignment

Cells exhibit chiral orientation on micropatterned stripes, which reflects the development of left-right (LR) asymmetry in tissue microarchitecture. We previously reported a dependence of cell chirality on substrate stiffness, as more cells oriented with negative angles on glass but not on PDMS substrate. However, the mechanism remains unclear. Here, using an image processing method which automates segmentation of individual nucleus, we found that enhanced chirality correlates with an increased intercellular alignment on glass substrate. More interestingly, comparing image with low cell density (< 50,000 cells/cm₂ ) to high cell density (> 180,000 cells/cm₂ ), the increased cell density does not improve the intercellular alignment but only reduces the distance between neighbouring cells, making the chirality independent of density range of tests.