bioRxiv2022
The collective migration of keratinocytes during wound healing requires both the generation and transmission of mechanical forces for individual cellular locomotion and the coordination of movement across cells. Leader cells along the wound edge transmit mechanical and biochemical cues to ensuing follower cells, ensuring their coordinated direction of migration across multiple cells. Despite the observed importance of mechanical cues in leader cell formation and in controlling coordinated directionality of cell migration, the underlying biophysical mechanisms remain elusive. The mechanically-activated ion channel PIEZO1 was recently identified to play an inhibitory role during the reepithelialization of wounds. Here, through an integrative experimental and mathematical modeling approach, we elucidate PIEZO1s contributions to collective migration. Time-lapse microscopy reveals that PIEZO1 activity inhibits leader cell formation at the wound edge. To probe the relationship between PIEZO1 activity, leader cell formation and inhibition of reepithelialization, we developed an integrative 2D continuum model of wound closure that links observations at the single cell and collective cell migration scales. Through numerical simulations and subsequent experimental validation, we found that coordinated directionality plays a key role during wound closure and is inhibited by upregulated PIEZO1 activity. We propose that PIEZO1-mediated retraction suppresses leader cell formation which inhibits coordinated directionality between cells during collective migration. Author summaryDuring the healing of a wound, cells called keratinocytes that make up the outer layer of the skin migrate collectively to close the wound gap. The mechanically activated ion channel PIEZO1 was previously found to inhibit wound closure. Here, through a combined modeling and experimental approach, we investigate the role of PIEZO1 in regulating collective migration. Specialized cells called leader cells, which typically form along the wound edge, are important for guiding the migration of neighboring cells. These leader cells dictate the coordinated directionality, or the cohesiveness of the migration direction between neighboring cells, through the transmission of mechanical and biochemical cues. We find that PIEZO1 activity inhibits the formation of these leader cells and, as a result, inhibits cell coordinated directionality causing the collective movement of cells to become disorganized and less effective in closing the wound. Our findings shed light on the complex mechanisms underlying collective migration, providing valuable insight into how mechanical cues affect the movement of cells during wound closure.