Human adipose-derived mesenchymal stem cell-derived exosomes induce epithelial remodeling and anti-scar healing revealed by single-cell RNA sequencing

Effectively managing skin wounds to achieve quick and scarless healing is a significant clinical challenge. Several cell types participate in wound healing, including keratinocytes, fibroblasts, and many others. Human adipose-derived mesenchymal stem cell-derived exosomes (hADSC-Exos) are regarded as promising therapeutic choice. However, a comprehensive understanding of what mechanisms promote regenerative healing respond to hADSC-Exos treatment is still limited. Here, we utilize a high-resolution single-cell RNA sequencing analysis (scRNA-seq) from adult wild-type mice, postoperative day (POD) 14 mice and hADSC-Exos-treated postoperative day (POD) 14 mice. hADSC-Exos influences epithelial cells and fibroblasts, leading to scar-free wound healing. Among epithelial cell subtypes, Lef1high proliferating keratinocytes (prolif KC) are particularly remodeled by hADSC-Exos. Prolif KC exhibit epithelial-mesenchymal plasticity (EMP). The cell-cell communication between keratinocytes and fibroblasts in anti-scar healing is modulated by TGF-β1, which promote EMP transition cascade. hADSC-Exos may inhibit wound fibrosis through the 14-3-3Zeta-YES-associated protein (YAP)-hippo signaling pathway. This study enhances our understanding of epithelial cell diversity and interactions in wound healing, highlighting hADSC-Exos-induced prolif KC as potential reprogramming targets. These epithelial cells present promising therapeutic targets for improving wound healing strategies. scRNA-seq profiling of skin from adult, POD14, POD14-Exo