PIEZO1-induced cellular retraction controls keratinocyte migration in wound healing

Keratinocytes are the predominant cell type of the epidermis and form an important protective barrier to the external environment. During the healing of wounded skin, keratinocytes migrate from the wound edge to reinstate the epithelial barrier 1,2. Mechanical cues are important regulators of cell migration in this process 3-7; however, the molecular transducers and biophysical mechanisms of this mechanoregulation remain elusive. Here, we show through molecular, cellular and organismal studies that the mechanically-activated ion channel PIEZO1 regulates keratinocyte migration through dynamic cellular localization which dictates retraction events. Single keratinocytes isolated from an epidermal-specific Piezo1 knockout mouse moved faster and migrated farther than littermate controls. To determine how PIEZO1 may contribute to cell migration, we imaged the localization of endogenous channels in migrating keratinocytes over several hours. We found that enrichment of PIEZO1 channel puncta correlated with cellular retraction in migrating single cells and in collectively migrating monolayers. Strikingly, PIEZO1 activation with Yoda1 resulted in increased retraction events in single cells as well as in monolayers of keratinocytes. During in vitro scratch assays, Yoda1-induced activation of PIEZO1 caused slower wound closure due to increased retraction events at the wound. Conversely, channel deletion resulted in faster scratch wound closure. This result was mirrored in vivo whereby epidermal-specific PIEZO1 knockout mice exhibited faster wound closure compared to littermate controls, and epidermal-specific PIEZO1 gain-of-function mice displayed slower wound closure. Overall, our findings show that reducing Piezo1 activity can accelerate wound healing, suggesting a potential pharmacological target for wound treatment. More broadly, we show that molecular-scale spatiotemporal dynamics of Piezo1 channels controls tissue-scale cell migration, a cellular process of fundamental importance in development, homeostasis and repair.