Condensation tendency of connected contractile tissue with planar isotropic actin network

It has been found that many types of cells form nematic symmetry on confined planar substrates. Such observation has been satisfactorily explained by modeling cells as crowded self-propelled rods. In this work, we report that rat embryonic fibroblast (REF) cells when confined in circular mesoscale patterns, form a new type of symmetry where cells align radially at the boundary. Unlike NIH-3T3 and MDCK monolayers, the REF monolayer presents a supracellular actin gradient with isotropic meshwork. In addition, the contractile REF cells present strong adhesive interactions with neighboring cells, which confers the monolayer with significant condensation tendency. We found the loss of condensation tendency by inhibiting the cell contractility or disrupting cell-cell adhesion led to the disappearance of the radial alignment. In theory, we found the prestretch due to condensation tendency with differential cell stiffness is sufficient to explain the new symmetry within a confined tissue continuum.

已经发现，许多类型的细胞在受限平面底物上形成nematic对称性。通过将细胞建模为拥挤的自propelled棒，可以令人满意地解释这种观察。在这项工作中，我们报告说，大鼠胚胎成纤维细胞（REF）细胞限制在圆形的中尺度模式时，形成一种新型的对称性，其中细胞在边界处径向对齐。与NIH-3T3和MDCK单层不同，REF单层具有各向同性网状的肌动蛋白梯度。此外，收缩的REF细胞与邻近细胞具有强烈的粘合剂相互作用，这使单层具有明显的冷凝趋势。我们发现，通过抑制细胞收缩性或破坏细胞 - 细胞粘附导致径向比对消失，发现凝结趋势的丧失。从理论上讲，我们发现，由于具有差分细胞刚度的凝结趋势而引起的prestretch足以解释密闭组织连续体内的新对称性。