title: Cell reorientation under cyclic stretching.
abstract: Mechanical cues from the extracellular microenvironment play a central role in regulating the structure, function and fate of living cells. Nevertheless, the precise nature of the mechanisms and processes underlying this crucial cellular mechanosensitivity remains a fundamental open problem. Here we provide a novel framework for addressing cellular sensitivity and response to external forces by experimentally and theoretically studying one of its most striking manifestations--cell reorientation to a uniform angle in response to cyclic stretching of the underlying substrate. We first show that existing approaches are incompatible with our extensive measurements of cell reorientation. We then propose a fundamentally new theory that shows that dissipative relaxation of the cell's passively-stored, two-dimensional, elastic energy to its minimum actively drives the reorientation process. Our theory is in excellent quantitative agreement with the complete temporal reorientation dynamics of individual cells measured over a wide range of experimental conditions, thus elucidating a basic aspect of mechanosensitivity.
authors.affiliation: Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Ariel
authors.initials: A
authors.lastname: Livne
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Bouchbinder
authors.affiliation: Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Geiger
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D002460:Cell Line; D016764:Cell Polarity / Q000502:physiology*; D005347:Fibroblasts / Q000502:physiology*; D009038:Motion; D051381:Rats; D013314:Stress, Mechanical