Location of injury influences the mechanisms of both regeneration and repair within the MRL/MpJ mouse.
The adult MRL/MpJ mouse regenerates all differentiated structures after through-and-through ear punch wounding in a scar-free process. We investigated whether this regenerative capacity was also shown by skin wounds. Dorsal skin wounds were created, harvested and archived from the same animals (MRL/MpJ and C57BL/6 mice) that received through-and-through ear punch wounds. Re-epithelialization was complete in dorsal wounds in both strains by day 5 and extensive granulation tissue was present by day 14 post-wounding. By day 21, wounds from both strains contained dense amounts of collagen that healed with a scar. The average wound area, as well as alpha-smooth muscle actin expression and macrophage influx were investigated during dorsal skin wound healing and did not significantly differ between strains. Thus, MRL/MpJ mice regenerate ear wounds in a scar-free manner, but heal dorsal skin wounds by simple repair with scar formation. A significant conclusion can be drawn from these data; mechanisms of regeneration and repair can occur within the same animal, potentially utilizing similar molecules and signalling pathways that subtly diverge dependent upon the microenvironment of the injury.
Beare
Alice H M
AH
UK Centre for Tissue Engineering, Faculty of Life Sciences, University of Manchester, Manchester, UK.
Metcalfe
Anthony D
AD
Ferguson
Mark W J
MW
D000199:Actins / Q000032:analysis; D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis; D001415:Back; D015415:Biomarkers / Q000032:analysis; D049109:Cell Proliferation; D004431:Ear, External / Q000293:injuries / Q000473:pathology; D005260:Female; D006097:Granulation Tissue / Q000473:pathology; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D019463:Mice, Inbred MRL lpr; D012867:Skin / Q000293:injuries / Q000473:pathology; D012879:Skin Physiological Phenomena; D014945:Wound Healing / Q000502:physiology*; D014950:Wounds, Penetrating / Q000473:pathology*
D000199:Actins; D000943:Antigens, Differentiation; D015415:Biomarkers; C036763:monocyte-macrophage differentiation antigen