Aix Marseille Univ, CNRS, ISM, Marseille, France; Department of Orthopaedics and Traumatology, Institute for Locomotion, APHM, Sainte-Marguerite Hospital, Marseille, France.
Université de Haute-Alsace, CNRS, IS2M, UMR 7361, Mulhouse, France; Université de Strasbourg, Strasbourg, France.
Biophys J. 2019 Sep 17;117(6):1136-1144. doi: 10.1016/j.bpj.2019.07.022. Epub 2019 Jul 22.
The latest experiments have shown that adherent cells can migrate according to cell-scale curvature variations via a process called curvotaxis. Despite identification of key cellular factors, a clear understanding of the mechanism is lacking. We employ a mechanical model featuring a detailed description of the cytoskeleton filament networks, the viscous cytosol, the cell adhesion dynamics, and the nucleus. We simulate cell adhesion and migration on sinusoidal substrates. We show that cell adhesion on three-dimensional curvatures induces a gradient of pressure inside the cell that triggers the internal motion of the nucleus. We propose that the resulting out-of-equilibrium position of the nucleus alters cell migration directionality, leading to cell motility toward concave regions of the substrate, resulting in lower potential energy states. Altogether, we propose a simple mechanism explaining how intracellular mechanics enable the cells to react to substratum curvature, induce a deterministic cell polarization, and break down cells basic persistent random walk, which correlates with latest experimental evidences.
最新实验表明,贴壁细胞可以通过一种称为趋曲率的过程根据细胞尺度的曲率变化进行迁移。尽管已经确定了关键的细胞因子,但对其机制仍缺乏清晰的认识。我们采用了一种力学模型,该模型详细描述了细胞骨架丝网络、粘性细胞质、细胞黏附动力学和细胞核。我们模拟了细胞在正弦形基底上的黏附和迁移。我们表明,细胞在三维曲面上的黏附会在细胞内产生压力梯度,从而触发细胞核的内部运动。我们提出,细胞核的这种非平衡位置会改变细胞迁移的方向性,导致细胞向基底的凹区运动,从而达到更低的势能状态。总的来说,我们提出了一个简单的机制,解释了细胞内力学如何使细胞能够对基底曲率做出反应,诱导细胞的确定性极化,并打破细胞基本的持续随机游走,这与最新的实验证据相吻合。