Piezo1-Mediated Calcium Flux Transfers Mechanosignal to Yes-Associated Protein to Stimulate Matrix Production in Keloid.

Keloids are fibroproliferative diseases affecting millions of people worldwide, but curing keloids remains challenging. Mechanical force is a common initiator and driver of keloids, and blocking the proadhesive signaling pathways is expected to cure keloids. This study found higher levels of Piezo1 in human keloid fibroblasts than in normal skin fibroblasts. Single-cell transcriptome analysis revealed a correlation of Piezo1 with Yes-associated protein (YAP) in keloid fibroblasts. Knockdown of Piezo1/YAP in keloid fibroblasts versus fibroblasts decreased CCN2 and CCN1 expression and fibrosis-related cell behaviors, identifying Piezo1 and YAP as upstream signals of proadhesive signaling loop in keloids. Treatment of patient-derived keloid xenograft model with Piezo1 inhibitor GsMTx4 and YAP inhibitor verteporfin reduced keloid volume and decreased type I/III collagen ratio. Atomic force microscopy further confirmed the biomechanical improvements of keloids in elasticity, viscoelasticity, and roughness ex vivo. In addition, the calcium ion-sensitive fluorescent indicator Fluo-3/AM and double-labeling immunofluorescence stains showed that Piezo1 transferred mechanosignal to increase YAP nuclear translocation through calcium flux. Finally, transcriptomics revealed target genes of the Piezo1/YAP signaling pathway, such as TBX3, SESN2, SMAD7, FOSB, JARID2, and HAS2. Consequently, the Piezo1/calcium flux/YAP signaling axis contributes to the mechanically induced proadhesive signaling pathway, and thus, Piezo1 and YAP are promising targets for keloid treatment.