Tissue Fluidity Promotes Epithelial Wound Healing

Summary Epithelial tissues are inevitably damaged from time to time and must therefore have robust repair mechanisms. The behaviour of tissues depends on their mechanical properties and those of the surrounding environment 1 . However, it remains poorly understood how tissue mechanics regulates wound healing, particularly in in vivo animal tissues. Here we show that by tuning epithelial cell junctional tension, we can alter the rate of wound healing. We observe cells moving past each other at the wound edge by intercalating, like molecules in a fluid, resulting in seamless wound closure. Using a computational model, we counterintuitively predict that an increase in tissue fluidity, via a reduction in junctional tension, can accelerate the rate of wound healing. This is contrary to previous evidence that actomyosin tensile structures are important for wound closure 2–6 . When we experimentally reduce tissue tension, cells intercalate faster and wounds close in less time. The role we describe for tissue fluidity in wound healing, in addition to its known roles in developing 7,8 and mature tissues 9 , reinforces the importance of the fluid state of a tissue.