Our cells push and pull against the world around them, using mechanical forces to get things done – growing, moving, perhaps changing shape. Tiny tensions are essential for development and tissue repair, but also help diseases like cancer progress. These mouse kidney cells are growing on shaped platforms, trapped so scientists can watch them squirm. A fibre-like protein called talin, which props up each cell’s cytoskeleton, is attached to a new type of sensor – it produces fluorescence (green) depending on how much the fibres stretch. We can see the talin under tension at the corners of the triangular cell. The sensor makes it possible to measure these tiny piconewton forces, trillions of times smaller than those needed to win a tug-o-war. Combining this stress test with visual clues from different fibres (purple and grey), may give future clues to pushing healthy cells further, while making cancerous ones fold under pressure.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.