Location of injury influences the mechanisms of both regeneration and repair within the MRL/MpJ mouse

J Anat. 2006 Oct;209(4):547-59. doi: 10.1111/j.1469-7580.2006.00641.x.

Abstract

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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / analysis
  • Animals
  • Antigens, Differentiation / analysis
  • Back
  • Biomarkers / analysis
  • Cell Proliferation
  • Ear, External / injuries
  • Ear, External / pathology
  • Female
  • Granulation Tissue / pathology
  • Immunohistochemistry / methods
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred MRL lpr
  • Skin / injuries
  • Skin / pathology
  • Skin Physiological Phenomena*
  • Wound Healing / physiology*
  • Wounds, Penetrating / pathology*

Substances

  • Actins
  • Antigens, Differentiation
  • Biomarkers
  • monocyte-macrophage differentiation antigen