Department of Engineering Mechanics, Soft Matter Research Center, Zhejiang University, Hangzhou, Zhejiang, China.
PLoS One. 2013 Jun 6;8(6):e65864. doi: 10.1371/journal.pone.0065864. Print 2013.
We report a theoretical study on the cyclic stretch-induced reorientation of spindle-shaped cells. Specifically, by taking into account the evolution of sub-cellular structures like the contractile stress fibers and adhesive receptor-ligand clusters, we develop a mechanochemical model to describe the dynamics of cell realignment in response to cyclically stretched substrates. Our main hypothesis is that cells tend to orient in the direction where the formation of stress fibers is energetically most favorable. We show that, when subjected to cyclic stretch, the final alignment of cells reflects the competition between the elevated force within stress fibers that accelerates their disassembly and the disruption of cell-substrate adhesion as well, and an effectively increased substrate rigidity that promotes more stable focal adhesions. Our model predictions are consistent with various observations like the substrate rigidity dependent formation of stable adhesions and the stretching frequency, as well as stretching amplitude, dependence of cell realignment. This theory also provides a simple explanation on the regulation of protein Rho in the formation of stretch-induced stress fibers in cells.
我们报告了一项关于纺锤形细胞在周期性拉伸诱导下重新取向的理论研究。具体来说，通过考虑细胞内结构（如收缩应力纤维和黏附受体-配体簇）的演变，我们开发了一个机械化学模型来描述细胞对周期性拉伸基底的重新排列的动力学。我们的主要假设是细胞倾向于在最有利于形成应力纤维的方向上定向。我们表明，当受到周期性拉伸时，细胞的最终取向反映了应力纤维内升高的力的促进其解聚和细胞-基底黏附的破坏之间的竞争，以及有效增加的基底刚性，促进更稳定的黏附斑。我们的模型预测与各种观察结果一致，例如，基底刚性依赖于稳定黏附的形成以及细胞重排对拉伸频率和拉伸幅度的依赖性。该理论还对蛋白 Rho 在细胞中拉伸诱导的应力纤维形成中的调节提供了一个简单的解释。
