The super super-healing MRL mouse strain

Abstract

The Murphy Roths Large (MRL/MpJ) mice provide unique insights into wound repair and regeneration. These mice and the closely related MRL/MpJ-Faslpr/J and Large strains heal wounds made in multiple tissues without production of a fibrotic scar. The precise mechanism of this remarkable ability still eludes researchers, but some data has been generated and insights are being revealed. For example, MRL cells reepithelialize over dermal wound sites faster than cells of other mouse strains. This allows a blastema to develop beneath the protective layer. The MRL mice also have an altered basal immune system and an altered immune response to injury. In addition, MRL mice have differences in their tissue resident progenitor cells and certain cell cycle regulatory proteins. The difficulty often lies in separating the causative differences from the corollary differences. Remarkably, not every tissue in these mice heals scarlessly, and the specific type of wound and priming affect regeneration ability as well. The MRL/MpJ, MRL/MpJ-Faslpr/J, and Large mouse strains are also being investigated for their autoimmune characteristic. Whether the two phenotypes of regeneration and autoimmunity are related remains an enigma.

An Articular Cartilage Repair Model in Common C57Bl/6 Mice

“…25 This strain shows super-healing characteristics, not only of articular cartilage but also ear punch wounds and neonatal digit amputation. 26 Eltawil et al reported that DBA/1 mice also showed high potential for cartilage repair.…”

Looking Ahead to Engineering Epimorphic Regeneration of a Human Digit or Limb

“…In this system, however, a blastema-like structure does not form and regeneration is instead stem cell dependent. Another mammalian model is the immunocompromised MRL/ MpJ mouse, which is considered to have a greater regenerative capacity compared to most other strains 85 and in particular regenerates ear tissue without scarring after a hole punch. 86 The regenerative process of the ear mimics elements of amphibian epimorphic regeneration, including ECM histolysis, 87 formation of a blastema-like structure, 88 and regrowth of multiple tissue structures.…”

Mapping Novel Subcutaneous Angiogenesis Quantitative Trait Loci in [B6×MRL]F2 Mice

“…15 interaction is detected between markers rs13482752 (58 cM) and D8Mit211, markers previously used to detect Heal1 on Chr. 8. 6 This interaction also requires homozygous B6…”

“…8 This complex trait is shared with the large (LG/J, abbreviated LG) mouse strain and many QTLs have been associated with healing in these strains; however, none of these QTLs have been identified. 2,5 Wound healing can be broken down into temporal phases that include, hemostasis, inflammation, proliferation, and remodeling.…”

“…2,5 Wound healing can be broken down into temporal phases that include, hemostasis, inflammation, proliferation, and remodeling. 8 The genetic factors that influence a wound healing study are dependent on the timing during which data are collected. For example, MRL and LG mice are known to remove and reestablish basement membrane in the resolution phase of healing, whereas other strains do not.…”