Dendritic Cell-Associated MARCKSL1 Regulates Fibroblast Differentiation During Wound Healing.

Following tissue injury, diverse cell populations, including immune cells such as dendritic cells, converge at the damaged site. They actively contribute to scar formation through intricate crosstalk with fibroblasts, exceeding their role as antigen-presenting entities. Consequently, they are emerging as promising therapeutic targets. Through single-cell RNA sequencing analysis of adult murine scar tissue, we identified the gene expression of myristoylated alanine-rich C-kinase substrate-like 1 (MARCKSL1) within dendritic cell clusters localised in fibrotic regions. Using our proprietary mouse fetal wound healing model, we observed a distinct accumulation of MARCKSL1-positive dendritic cells at the wound margins during the developmental stage, coinciding with the onset of scar formation. Stimulation with transforming growth factor beta 1 (TGF-β1), serving as a mimic of wound-induced signalling, enhanced MARCKSL1 expression in mouse dendritic cells. Co-culturing TGF-β1-stimulated dendritic cells with fibroblasts promoted fibroblast differentiation into myofibroblasts, whereas this effect was markedly diminished in dendritic cells transduced with MARCKSL1 shRNA. Moreover, mice treated with a MARCKSL1 inhibitor (MANS peptide) exhibited significantly attenuated scar formation compared with controls. Overall, these findings demonstrated that MARCKSL1 expression in dendritic cells modulates fibroblast activity and is associated with fibrotic responses during wound healing. Regulation of MARCKSL1 dynamics in dendritic cells could offer a potential therapeutic avenue for scar prevention and regenerative wound healing.