title: A Tensegrity Model of Cell Reorientation on Cyclically Stretched Substrates.
abstract: Deciphering the mechanisms underlying the high sensitivity of cells to mechanical microenvironments is crucial for understanding many physiological and pathological processes, e.g., stem cell differentiation and cancer cell metastasis. Here, a cytoskeletal tensegrity model is proposed to study the reorientation of polarized cells on a substrate under biaxial cyclic deformation. The model consists of four bars, representing the longitudinal stress fibers and lateral actin network, and eight strings, denoting the microfilaments. It is found that the lateral bars in the tensegrity, which have been neglected in most of the existing models, can play a vital role in regulating the cellular orientation. The steady orientation of cells can be quantitatively determined by the geometric dimensions and elastic properties of the tensegrity elements, as well as the frequency and biaxial ratio of the cyclic stretches. It is shown that this tensegrity model can reproduce all available experimental observations. For example, the dynamics of cell reorientation is captured by an exponential scaling law with a characteristic time that is independent of the loading frequency at high frequencies and scales inversely with the square of the strain amplitude. This study suggests that tensegrity type models may be further developed to understand cellular responses to mechanical microenvironments and provide guidance for engineering delicate cellular mechanosensing systems.
authors.affiliation: International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an, China. Electronic address: guangkuixu@mail.xjtu.edu.cn.
authors.forename: Guang-Kui
authors.initials: GK
authors.lastname: Xu
authors.affiliation: Institute of Biomechanics and Medical Engineering, Department of Engineering Mechanics, Tsinghua University, Beijing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: Institute of Biomechanics and Medical Engineering, Department of Engineering Mechanics, Tsinghua University, Beijing, China. Electronic address: fengxq@tsinghua.edu.cn.
authors.forename: Xi-Qiao
authors.initials: XQ
authors.lastname: Feng
authors.affiliation: School of Engineering, Brown University, Providence, Rhode Island.
authors.forename: Huajian
authors.initials: H
authors.lastname: Gao
mesh_terms: D000199:Actins / Q000378:metabolism; D000465:Algorithms; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D004548:Elasticity; D008954:Models, Biological; D017711:Nonlinear Dynamics
chemical_list: D000199:Actins