Evidence for articular cartilage regeneration in MRL/MpJ mice

Abstract

Male MRL/MpJ mice appear to possess an intrinsic ability to 'regenerate' articular cartilage. Understanding the biochemical and genetic basis for articular cartilage regeneration may open up new treatment options for traumatic articular cartilage defects.

Evaluating endogenous repair of focal cartilage defects in C57BL/6 and MRL/MpJ mice using 9.4T magnetic resonance imaging: A pilot study

“…In support of previous studies [2,3], we found that at 4 weeks post-injury, repair in MRL mice was significantly superior to repair in C57 animals (Fig. 2).…”

“…After decalcification was completed, samples are washed with water and underwent tissue processing and embedding. Paraffin-embedded tissue sections at 7 μm thick were stained with Safranin-O and graded using a scoring matrix previously described [3].…”

“…At 4 and 8 weeks after injury, MRL mice did not show the gross morphological changes that occurred in the C57 mice [2]. In a separate study, the authors induced full thickness cartilage lesions in C57 and MRL mice and evaluated injury sites at 6 and 12 weeks [3]. The authors observed that full thickness lesions resulted in significant repair in MRL mice at both 6 and 12 week time points, while limited to no repair was observed in C57 mice over the same period of time [3].…”

“…In a separate study, the authors induced full thickness cartilage lesions in C57 and MRL mice and evaluated injury sites at 6 and 12 weeks [3]. The authors observed that full thickness lesions resulted in significant repair in MRL mice at both 6 and 12 week time points, while limited to no repair was observed in C57 mice over the same period of time [3]. Furthermore, the repair tissue was comprised of chondrocytes and exhibited a hyaline cartilagelike structure including proteoglycan and collagen expression.…”

Cardinal Regenerative Features of the MRL Mouse — An Update

“…Interestingly, the wild type MRL/MpJ also displays a somewhat reduced level of autoimmunity. Further studies showed evidence of regeneration in many tissues including heart myocardium (Leferovich et al, 2001;Naseem et al, 2007;Alfaro et al, 2008), digit Chadwick et al, 2007), articular cartilage (Fitzgerald et al, 2008), cornea (Ueno et al, 2005) and peripheral nerves (Buckley et al, 2010). One specific type of injury in a given location, a flank or dorsal skin wound, has given mixed results.…”