Blocking a specific cell-signalling pathway in mice boosts the regeneration of ear tissue without any scarring after injury.

Some amphibians and fish can regrow organs and appendages. To investigate the process in mammals, Thomas Leung, Seung Kim and their colleagues at Stanford University in California studied an engineered mouse model that is adept at regrowing injured ear tissue with no scarring. They found that certain cells in the skin's outer layer produced lower levels of a cell-signalling molecule called Sdf1 than seen in normal animals. This resulted in reduced recruitment of specific white blood cells that are involved in scar formation.

A compound that inhibits the signalling between Sdf1 and these white blood cells enhanced scar-free regrowth of ear tissue in normal mice.

Genes Dev. 29, 2097–2107 (2015)