757 Wound healing in aged skin exhibits systems-level alterations in cellular composition and cell-cell communication

This study investigated the differences in wound healing between young and aged skin using single-cell RNA sequencing. It revealed significant changes in cellular composition and molecular profiles, particularly highlighting a more inflammatory phenotype in aged mice. A novel inflammatory Arg1Hi macrophage subset was identified in aged wounds, with altered immune cell compositions compared to younger counterparts. The study also found disrupted communication between fibroblasts and Arg1Hi macrophages, with increased osteospontin (OPN) expression in aged macrophages during mid- and late-stages of healing, potentially contributing to delayed wound healing in aged skin. These findings provided insights for future research on wound healing mechanisms.