Eigenstrain as a mechanical set-point of cells

Authors

Shengmao Lin, University of Nebraska-LincolnFollow
Marsha C. Lampi, Cornell University
Cynthia A. Reinhart-King, Cornell UniversityFollow
Gary C.P. Tsui, Hong Kong Polytechnic UniversityFollow
Jian Wang, University of Nebraska-LincolnFollow
Carl A. Nelson, University of Nebraska-LincolnFollow
Linxia Gu, University of Nebraska-LincolnFollow

Date of this Version

2-2018

Citation

Published in Biomechanics and Modeling in Mechanobiology 17 (2018), 951–959.

doi 10.1007/s10237-018-1004-0

Comments

Copyright © 2018 Springer-Verlag GmbH Germany, part of Springer Nature 2018. Used by permission.

Abstract

Cell contraction regulates how cells sense their mechanical environment. We sought to identify the set-point of cell contraction, also referred to as tensional homeostasis. In this work, bovine aortic endothelial cells (BAECs), cultured on substrates with different stiffness, were characterized using traction force microscopy (TFM). Numerical models were developed to provide insights into the mechanics of cell–substrate interactions. Cell contraction was modeled as eigenstrain which could induce isometric cell contraction without external forces. The predicted traction stresses matched well with TFM measurements. Furthermore, our numerical model provided cell stress and displacement maps for inspecting the fundamental regulating mechanism of cell mechanosensing. We showed that cell spread area, traction force on a substrate, as well as the average stress of a cell were increased in response to a stiffer substrate. However, the cell average strain, which is cell type-specific, was kept at the same level regardless of the substrate stiffness. This indicated that the cell average strain is the tensional homeostasis that each type of cell tries to maintain. Furthermore, cell contraction in terms of eigenstrain was found to be the same for both BAECs and fibroblast cells in different mechanical environments. This implied a potential mechanical set-point across different cell types. Our results suggest that additional measurements of contractility might be useful for monitoring cell mechanosensing as well as dynamic remodeling of the extracellular matrix (ECM). This work could help to advance the understanding of the cell-ECM relationship, leading to better regenerative strategies.