Force Transduction Mechanisms At Adherens Junctions

Mechanical forces are major determinants of cell and tissue development. During tissue development, cells experience numerous mechanical forces including tensile or compressive forces from shape change of the surrounding tissues and shear force from fluid flow in tubular structures. In the lining of the lungs, blood vessels and the kidney cells that line tubular structures adhere directly to their neighbors by junctions that join the fibrous internal cellular cytoskeleton. The cell-to-cell connections transmit forces between the cells. The intercellular connections are part of how lung, kidney and vascular lining cells can measure the forces of fluid flow or air pressure. The objective of this research is to mimic how the forces of fluid flow are coupled to the cell-cell junctions and how they cause cell structural changes in the cells that make them function properly. Failure of cells properly to sense and transmit mechanical signals can cause progression of diseases of the kidney, vasculature and lung. Our understanding of force transmission pathways has been limited due to a lack of tools to measure forces in specific proteins in live cells. This research will use a novel approach of combining FRET based force sensors with microfluidics that presents an opportunity to establish the link between flow-induced cytoskeletal forces and adherens junction (AJ) dynamics responsible for cell remodeling. The distribution of cytoskeletal force and its time-dependence for specific proteins will be mapped using FRET probes in cells subjected to flow stimuli. Adherens junction dynamics will be measured simultaneously with fluorescently labeled junction proteins. The outcome of this research will be a new understanding of the dynamics of shear force transduction in living cells, and perhaps most importantly, a measure of the cause and effect relationships of energy flow in the cell. The FRET force probes would also provide a new research toolset to the scientific community to study cell mechanics. The educational broader impacts will be accomplished through a unique program on Education through Experimentation or E2E