Shuling Fan, M.D., Research Lab Specialist (Parkos and Nusrat Laboratory), Department of Pathology, University of Michigan Medical School 

The intestinal lining consists of only a single layer of epithelial cells. This thin covering forms an incredibly effective defense barrier against external noxious substances and pathogens, while also playing a critical role in water and nutrient absorption. In pathologic states such as inflammatory bowel disease, this barrier can be breached. In response to such an injury, the epithelial cells nearby migrate as a collective sheet to heal the wound and restore the barrier. This image shows mouse intestinal epithelial cells that are migrating towards an empty wound space. Cell nuclei are outlined in blue. The leading cells are spread out as they flatten into a stingray shape. They project tentacles that are rich in a stiff actin cytoskeleton (red) and attach to the underlying matrix using sticky spots called focal adhesions (green). Tentacles act as sensors to direct this coordinated cell repair movement.

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