FGF signaling induces the regeneration of collagen fiber structure during skin wound healing in axolotls

Axolotls have been considered to be able to regenerate their skin completely. Our recent study updated this theory with the finding that the lattice structure of dermal collagen fibers was not fully regenerated after skin injury. We also discovered that nerves induce the regeneration of collagen fibers. The mechanism of collagen fiber regeneration remains unknown, however. In this study, we focused on the structure of collagen fibers with collagen braiding cells, and cell origin in axolotl skin regeneration. In the wounded dermis, cells involved in skin repair/ regeneration were derived from both the surrounding dermis and the subcutaneous tissue. Regardless of cell origin, cells acquired the proper cell morphology to braid collagen fiber with nerve presence. We also found that FGF signaling could substitute for the nerve roles in the conversion of subcutaneous fibroblasts to lattice-shaped dermal fibroblasts. Our findings contribute to the elucidation of the fundamental mechanisms of true skin regeneration and provide useful insights for pioneering new skin treatments.

Automated summary

Our study revealed that the lattice structure of dermal collagen fibers in axolotls is not fully regenerated after skin injury, but can be induced by nerves. The mechanism of collagen fiber regeneration remains unknown. We found that cells involved in skin repair/regeneration are derived from both the surrounding dermis and subcutaneous tissue, and can braid collagen fibers with the presence of nerves. Additionally, FGF signaling can substitute for nerve roles in the conversion of subcutaneous fibroblasts to lattice-shaped dermal fibroblasts. Our findings contribute to understanding the fundamental mechanisms of skin regeneration and have potential implications for developing new skin treatments.