Apoptosis recognition receptors regulate skin tissue repair in mice

Apoptosis and clearance of apoptotic cells via efferocytosis are evolutionarily conserved processes that drive tissue repair. However, the mechanisms by which recognition and clearance of apoptotic cells regulate repair are not fully understood. Here, we use single-cell RNA sequencing to provide a map of the cellular dynamics during early inflammation in mouse skin wounds. We find that apoptotic pathways and efferocytosis receptors are elevated in fibroblasts and immune cells, including resident Lyve1+ macrophages, during inflammation. 7-9 week-old male C57BL/6J mice were wounded during the telogen phase of hair cycling. To assess cellular and molecular heterogeneity of the wound bed during the inflammatory phase, we performed scRNA-seq on cells isolated from 4 mm full-thickness biopsy punches on mouse back skin at 24 and 48 hours (h) after injury. To ensure that we also captured the immediately adjacent tissue as well as cells that may have migrated into the wound site, we used a 6mm biopsy punch to collect the tissue before isolating cells using enzymatic digestion.