Roles of Cell‐Cell Junction and Substrate Stiffness in Determining 3D Forces of Endothelial Cells

Abstract

Mechanical forces play an important role in regulating structure and functions of cells, including motility, proliferation, and survival. The integrity of cell‐cell junction is crucial in the physiological behavior of endothelial cells. Thus, it is essential to understand the modulation of endothelial cells by their micro‐environment such as substrate stiffness, confluency, and cell‐cell junction.We have developed three‐dimensional traction force microscopy (3D‐TFM) and intracellular force microscopy (3D‐IFM) to measure cell‐ECM, cell‐cell, and intracellular stresses of live cells in three dimensions at the subcellular level. These novel methods have been applied in order to investigate the mechanical responses of endothelial cells to changes in substrate stiffness, cell confluency, and cell‐cell junction. The results indicate that endothelial cells exhibit differences in the magnitude and spatial distribution of mechanical behaviors (traction and intracellular stress) and morphological features (area and aspect ratio) in response to substrate stiffness (1.5 kPa and 10b kPa hydrogel), cell confluency (existence of cell‐cell junction), and junction‐affecting drugs (thrombin and angiopoietin).We have shown that biophysical and biochemical environments are important in the control of endothelial cell structure and function. Studying how the forces are regulated spatially and temporally at the subcellular level in response to changes of cellular microenvironment can lead to further understanding of the physiology of endothelial cells and pathogenesis of vascular diseases.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.