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Updated: Jan 9, 2026
Murine Flexor Tendon Injury and Repair Surgery
Published on: September 19, 2016
Achilles tendons of MRL/MpJ mice show scar-mediated healing after tenotomy
Ningfeng Tang1, Divya S Sivalingam2, Kimberly Wilson1
1Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD, USA.
Purpose/Aim Of The Study:
Tendon healing in Murphy Roths Large (MRL/MpJ) mice was examined using an Achilles tendon tenotomy model, a full transection model, to compare with previous studies in which regenerative tendon healing was shown in a patellar tendon focal injury model.
Materials And Methods:
Achilles tendons of MRL/MpJ and C57BL/6J mice were fully transected. Tensile testing and proteomics analysis were performed after four weeks of healing. MicroCT was performed after 10 weeks of healing.
Results:
The Achilles tendons of MRL/MpJ mice healed via scar formation, regardless of sex, as did C57BL/6J mice. Tensile testing found that mechanical properties of injured tendons of both MRL/MpJ female and male mice were similar to those of C57BL/6J female and male mice, respectively, after four weeks of healing, which is during the remodeling phase. After 10 weeks of healing, injured tendons of MRL/MpJ mice possessed smaller heterotopic ossification volumes than those of C57BL/6J mice. Proteomics analysis revealed similar alterations to signaling pathways in injured tendons of MRL/MpJ and C57BL/6J male mice after four weeks of healing. However, among the altered pathways, actin cytoskeleton and integrin signaling pathways were two of the top pathways that were more prominently activated in C57BL/6J males than in MRL/MpJ males.
Conclusions:
These findings indicate that MRL/MpJ mice possess limited capacity to regenerate injured tendons after complete rupture, and that tenotomized Achilles tendons of MRL/MpJ male mice have lesser induction of heterotopic ossification and lower activation of the signaling pathways also induced with injury in C57BL/6J male mice.
