Deep Skin Fibroblast-Mediated Macrophage Recruitment Supports Acute Wound Healing

This study investigates the role of mesenchymal cells, specifically deep skin fibroblasts, in the early immune response following injury. Using single nuclei RNA-sequencing, researchers found that fibroblasts in deeper skin layers express higher levels of pro-inflammatory genes compared to keratinocytes and myeloid cells. SCA1+ fibroblasts, in particular, were enriched with chemokines like CCL2, CCL7, and IL33. The deletion of the Ccl2 gene in fibroblasts led to a decrease in macrophages and monocytes in the wound bed, resulting in impaired revascularization and re-epithelialization during healing. This highlights the crucial role of deep skin fibroblast-derived factors in inflammation and tissue repair.