Regeneration: The ultimate example of wound healing

The outcome of wound repair in mammals is often characterized by fibrotic scaring. Vertebrates such as zebrafish, frogs, and salamanders not only heal scarlessly, but also can regenerate lost appendages. Decades of study on the process of animal regeneration has produced key insights into the mechanisms of how complex tissue is restored. By examining our current knowledge of regeneration, we can draw parallels with mammalian wound healing to identify the molecular determinants that produce such differing outcomes.

► Amphibian limb regeneration occurs flawlessly to restore lost tissues.
► Mammalian wound often results in scarring.
► Formation of secretory epithelia is one of the key features of regenerating systems.
► Fibroblasts are differentiated into myofibroblasts in mammalian wounds.
► In contrast, fibroblasts acquire mesenchymal phenotype in regenerating systems.