Biophysical Society Thematic Meeting | Singapore

Mechanobiology of Disease

Poster Abstracts

19-POS Board 19 Spatial Mechanical Heterogeneity in Epithelial Cell Sheet : An Atomic Force Microscopy Study Yuki Fujii , Takaharu Okajima. Hokkaido University, Sapporo, Japan. In epithelial sheet, cells are tightly packed and connect the neighboring cells through cell junctions. These cells interact mechanically and migrate collectively by exerting tensile forces between cells and on extracellular matrix [1]. However, it is little known how the cell stiffness is regulated through the cell-cell mechanical interactions. In this study, we investigate the spatial distribution of the elastic modulus of epithelial Mardin-Darby canine kidney (MDCK) cell sheet in a large region by atomic force microscopy (AFM). MDCK cell sheet sample is prepared confluent condition. The AFM force curve measurements were used to map the spatial distribution of MDCK cells. We observed that the elastic modulus of MDCK cell sheet exhibits a characteristic spatial correlation length that is much longer than the distance between neighboring cells. This means that the elastic modulus of cell increases as the surrounding cells are stiffer whereas the elastic modulus decreases as the surrounding cells are softer. The magnitude of the elastic modulus was drastically reduced as actin filaments were depolymerized, and the spatial correlation of the cell elastic modulus was disappeared by disrupting actin filaments. Moreover, the reduction of the spatial correlation length was clearly observed as E-cadherin-dependent cell-cell adhesion was inhibited by EGTA. Interestingly, the spatial correlation length of the MDCK cells was recovered to that in the control condition as E-cadherin junctions between cells were again stabilized by washing out EGTA. The results suggest that the elastic modulus of epithelial cell sheet sensitively changes depending on the elastic modulus of the surrounding cells and the regulation of the cell elastic modulus is directly driven through the cell junctions. [1] E, Bazallieres., et al., Nature cell boil 17, 409-420 (2015).

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