Mouse digit AAV gene delivery into fibroblasts regulates regenerative outcome.

The distal mouse digit tip regenerates postamputation, while the proximal digit undergoes fibrosis. This study presents a comparative single-cell RNA sequencing-based analysis of regenerating and nonregenerating digits to computationally identify fibroblast subpopulations and genes associated with fibrosis and regeneration. To test the sufficiency of identified candidate genes to alter wound healing outcomes, we developed a robust adeno-associated virus gene delivery technique for digit fibroblasts. We found that overexpression of candidate profibrotic gene Pcolce2 or Prelp in the blastema modifies normal regeneration and overexpression of candidate proregenerative factor Ccl2 or Mest in the proximal digit substantially increases bone deposition. These data demonstrate that the computational analysis combined with the AAV delivery approach presented in this study provides a powerful framework for identifying the driving factors of fibrosis and regeneration in the mammalian digit.