Role of the Supracellular Actomyosin Cable during Epithelial Wound Healing

The closure of wounds in epithelia is center to many physiological processes in both development and repair of multicellular organisms. Depending on the biochemical and mechanical environment as well as cell type, this process often involves cell crawling and the purse-string contraction of a supracellular actomyosin ring around the wound. However, how these two mechanisms, especially the supracellular actomyosin ring, contribute to the wound healing is still unclear. To decipher this complex process, we develop a particle-based model that includes purse-string contraction, cell crawling and other properties incorporated with monolayers of Madin–Darby canine kidney (MDCK) cells. Our model captures the traction force patterns under several different conditions in experiments. In addition to traction force pointing away from the wound on the leading edge, we observed patterns of traction force pointing towards the wound. We show this inward pointing force pattern is induced by the purse-string contraction. By tuning the strength of the purse-string contraction and cell crawling, we depict the role of this actomyosin cable during wound healing. Our model can also explain which regulators affect the efficiency of these two mechanisms and how they interplay with each other.