The scarless heart and the MRL mouse.
The ability to regenerate tissues and limbs in its most robust form is seen in many non-mammalian species. The serendipitous discovery that the MRL mouse has a profound capacity for regeneration in some ways rivalling the classic newt and axolotl species raises the possibility that humans, too, may have an innate regenerative ability. The adult MRL mouse regrows cartilage, skin, hair follicles and myocardium with near perfect fidelity and without scarring. This is seen in the ability to close through-and-through ear holes, which are generally used for lifelong identification of mice, and the anatomic and functional recovery of myocardium after a severe cryo-injury. We present histological, biochemical and genetic data indicating that the enhanced breakdown of scar-like tissue may be an underlying factor in the MRL regenerative response. Studies as to the source of the cells in the regenerating MRL tissue are discussed. Such studies appear to support multiple mechanisms for cell replacement.
The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA. heberkatz@wistar.upenn.edu
Ellen
E
Heber-Katz
John
J
Leferovich
Khamilia
K
Bedelbaeva
Dmitri
D
Gourevitch
Lise
L
Clark
D000818:Animals; D002490:Central Nervous System / Q000502:physiology; D002921:Cicatrix / Q000503:physiopathology*; D003433:Crosses, Genetic; D005786:Gene Expression Regulation; D051379:Mice; D019463:Mice, Inbred MRL lpr; D009206:Myocardium; D040641:Quantitative Trait Loci; D012038:Regeneration / Q000235:genetics / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology*