Injured Mus and Acomys ear tissues at day0 were analyzed using 10X single-cell rna-seq

Macrophages play an essential role in tissue regeneration. However, the ability to dissect the role of macrophages in regeneration from their role in wound healing with scar has been hampered by a lack of comparative systems. In this study, we use a mammalian model of tissue regeneration and scar formation to contrast the role of macrophages in both wound healing paradigms. The African Spiny mouse (A. cahirinus) can regenerate tissue of the external ear pinnae after 4mm biopsy punch. The common lab mouse (M. musculus) forms a scar after the same injury. We test the potential of bone marrow derived macrophages from both species to activate local ear fibroblasts and find macrophages from A. cahirinus are able to induce a matrix turnover phenotype in fibroblasts from both species. We identify growth factors and cytokines specific to macrophages derived from A. cahirinus, and using single cell RNAseq and screening with these factors, we identify populations of macrophages unique to a regenerating injury compared to scar forming injury. Finally we test how macrophage populations change over time in a regenerating injury and how they differ from each stage in a scar forming system Injured Mus and Acomys ear tissues were analyzed using 10X single-cell rna-seq