Physical Society Colloquium

Making sense of Cell Mechanics

John Crocker

University of Pennsylvania

Mechanical stress and stiffness are increasingly recognized to play important roles in numerous cell biological processes, notably cell differentiation and tissue morphogenesis. Little definite is known, however, about how stress propagates through different cell structures or is converted to biochemical signals via mechanotransduction, due in large part to the difficulty of interpreting many cell mechanics experiments. Moreover, the different cell mechanics models in current use are mutually incompatible, do not explain the full range of cell mechanical behavior, and fail to make contact with cells' known molecular constituents. We employ a suite of different cell mechanics measurement methods in our lab to try to find a consensus description, in other words, to “make sense of cell mechanics”. This is a prerequisite for constructing useful models of cell mechanics that will make contact with cells' known molecular physiology. The picture of cells that is emerging from our recent studies is one of spatially separate compartments, each containing composite structures formed of distinct networks whose individual mechanical responses seem in line with expectations from soft-matter physics.