Digit regeneration is expedited in LG/J healer mice compared to SM/J non-healer mice

Limb loss resulting from disease or trauma affects an estimated 185,000 Americans annually, significantly reducing their quality of life. Consequently, successful attempts to regrow missing appendages could substantially improve the prognosis for amputees. In mice, the digit tip spontaneously regenerates resected tissues following distal amputation, whereas this capacity diminishes at more proximal levels after amputation. Moreover, regenerative potential is influenced by genetic variations among inbred mouse strains: LG/J (healer) mice exhibit superior reparative potential compared to SM/J (non-healer) mice. This study investigated the response to various levels of digit amputation in these mice to determine whether this strain-dependent healing response translates to the regeneration of complex tissues. Evaluation of skeletal regrowth, cell proliferation, and differential gene and protein expression reveals that digit regeneration is more robust in LG/J mice compared to SM/J mice at multiple amputation levels, suggesting that the regenerative capacity of composite tissues is genetically heritable in mice.