Cell Shape Changes During Wound Healing: New Insights into Epithelial Response

When the body sustains an injury, epithelial cells — which line surfaces both inside and outside the body — undergo remarkable shape changes to close the wound. Recent research has revealed that these cells adapt their internal structures, particularly the endoplasmic reticulum (ER), in response to the curvature of the wound edges. The ER adopts different configurations depending on whether the wound edge curves outward (convex) or inward (concave). At convex (outward) edges, the ER forms tube-like structures, facilitating cell crawling movements via broad, flat protrusions that help the cells migrate across the wound. Conversely, at concave (inward) edges, the ER reorganizes into flat sheets, supporting a 'purse-string' contraction mechanism where cells contract to pull the edges together. These distinct responses are driven by the mechanical forces acting on the edges: pushing forces at convex sites and pulling forces at concave ones, each triggering specific ER reorganization pathways. The ability of epithelial cells to dynamically remodel their internal organelles plays a crucial role in how they migrate to heal wounds. Scientists employed advanced imaging and mathematical modeling techniques to understand these processes, creating controlled models of tissue gaps to observe ER shape changes and cell movement. The findings, published in Nature Cell Biology and led by researchers from the UK and India, underscore the importance of the ER's structural plasticity in cellular mechanotransduction — the process by which mechanical stimuli are converted into biochemical signals. This discovery opens new avenues for understanding tissue repair, and could inform regenerative medicine and cancer research, by revealing how cells sense and respond to their mechanical environment during healing.