Biophysical Society Thematic Meeting | Singapore

Mechanobiology of Disease

Poster Abstracts

14-POS Board 14 E-cadherin Force Contributes to Lumen Homeostasis in Epithelial Acini Vani Narayanan, Daniel E. Conway . Virginia Commonwealth University, Richmond, VA, USA.

Little is known about the effects of protein-level mechanical forces on cell behavior in the context of an organized tissue structure. Epithelial cells cultured in a 3D environment comprising of extracellular matrix proteins form hollow spheroids of polarized cells known as acini or cysts. We hypothesized that forces across cell-cell junctions, specifically E-cadherin, are important regulators of these structures. Using a FRET-based tension biosensor in MDCK cells grown in Matrigel, we observed that E-cadherin forces were higher in 3D acini as compared to 2D monolayers. Using forskolin and a CFTR inhibitor to increase and decrease acini lumen pressure, respectively, we observed that E-cadherin force was affected by lumen pressure. Additionally, we were able to show that increased lumen pressure induces cell proliferation, requiring cytoskeletal-connected E-cadherin. Thus, changes in lumen pressure can regulate epithelial proliferation through E-cadherin forces, similar to prior work showing E-cadherin forces mediate stretch-induced proliferation in 2D. Next, we observed that cells expressing low- and zero-force mutants of E-cadherin had impaired lumen formation (multiluminated or complete absence of a lumen). In the case of the low-force mutant we were able to increase E-cadherin force and rescue acini to a single lumen using forskolin, further substantiating the role of E-cadherin force in acini homeostasis. Finally, we observed that E-cadherin force was reduced during the process of TGFß-induced EMT. Pre-treatment with forskolin was sufficient to block E-cadherin force changes, EMT, and lumen filling in TGFß treated cells. We are currently investigating if TGFß reduces E-cadherin force by altering lumen pressure, and also to determine if forskolin prevents EMT is through lumen pressure and/or E-cadherin forces. The major conclusion of these studies is that E-Cadherin tensile forces, which are modulated by lumen pressure, regulate the formation and homeostasis of epithelial acini.

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