A model for the contractility of the cytoskeleton including the effects of stress-fibre formation and dissociation
A model for the contractility of the cytoskeleton including the effects of stress-fibre formation and dissociation
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DOI：
10.1098/rspa.2006.1793
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发表时间：
2007-03-08
影响因子：
3.5
通讯作者：
Evans, Anthony G.
中科院分区：
文献类型：
--
作者：
Deshpande, Vikram S.;McMeeking, Robert M.;Evans, Anthony G.
提出了细胞收缩性模型，该模型解释了细胞骨架的动态重组。它由三个关键的生化过程驱动：(i) 触发肌动蛋白聚合和肌球蛋白磷酸化的激活信号，(ii) 肌动蛋白和肌球蛋白依赖张力组装成应力纤维，以及 (iii) 肌动蛋白和肌球蛋白之间的跨桥循环。产生紧张感的哀叹。提出了简单的关系来模拟这些耦合现象，并为单个应力纤维的激活和响应开发了本构定律。通过采用均质化分析，该定律被推广到二维和三维细胞骨架网络，并开发了有限应变连续体模型。该模型的主要特征通过考虑以下因素来说明：(i) 一系列支撑上的单个应力纤维和 (ii) 四个支撑上的二维方形单元。该模型被证明能够预测各种关键的实验确定的特征，包括：（i）随着支撑柔量的增加，细胞产生的力减少，（ii）细胞形状和边界条件对结构各向异性发展的影响，以及（iii）应力纤维在粘着斑和局部施加张力处的高浓度。此外，与实验结果一致，该模型预测多个激活信号比单个延长信号更能有效地形成应力纤维。
A model for the contractility of cells is presented that accounts for the dynamic reorganization of the cytoskeleton. It is motivated by three key biochemical processes: (i) an activation signal that triggers actin polymerization and myosin phosphorylation, (ii) the tension-dependent assembly of the actin and myosin into stress fibres, and (iii) the cross-bridge cycling between the actin and the myosin. laments that generates the tension. Simple relations are proposed to model these coupled phenomena and a constitutive law developed for the activation and response of a single stress fibre. This law is generalized to two-and three-dimensional cytoskeletal networks by employing a homogenization analysis and a finite strain continuum model is developed. The key features of the model are illustrated by considering: ( i) a single stress fibre on a series of supports and ( ii) a two-dimensional square cell on four supports. The model is shown to be capable of predicting a variety of key experimentally established characteristics including: ( i) the decrease of the forces generated by the cell with increasing support compliance, ( ii) the influence of cell shape and boundary conditions on the development of structural anisotropy, and ( iii) the high concentration of the stress fibres both at the focal adhesions and at the sites of localized applied tension. Moreover, consistent with the experimental findings, the model predicts that multiple activation signals are more effective at developing stress fibres than a single prolonged signal.