Transplantation of autologous mesenchymal stem cells during repair of detached rotator cuff muscle in sheep

The data describes the molecular, cellular and anatomical effect of the implantation of autologous mesenchymal stem cells (MSCs) in degenerated rotator cuff muscle of sheep. The aim of the onvestigation was that MSC injection would halt muscle-to-fat conversion subsequent to tendon repair by promoting growth and regeneration of muscle fibers.
Degeneration was induced for infraspinatus muscles of the right shoulder of Swiss Alpine sheep (n=14) by tendon release via osteotomy of the greater tuberosity. MSCs were prepared from bone marrow in a group of animals (T-MSC, n=8). They were characterised for their differentiation potential, fluorescently-labelled and grown as microtissues, before 0.9 Mio of them were injected in a specific area in the released muscle during tendon reattachment (repair). Two days (n=1), 2 weeks (n=1) and six weeks after repair (n=6) the effects of MSC implantation was characterised and compared against a group of sheep (n=6) where infraspinatus muscle was repaired after osteotomy but not being treated with MSCs.
Anatomical effects on muscle volume and composition were documented with radiological imaging of the entire muscle at baseline, during repair and six weeks after repair, and in MSC-injected, media-injected and non-injected areas six weeks after repair. Animal mass was determined with a balance. Cellular and molecular effects were characterised in biopsies being collected six weeks after repair from MSC-injected, media-injected and non-injected areas. Cellular effects were characterised by histological analysis of muscle sections for fiber type, fat and extracellular matrix composition. Molecular measures comprised biochchemical measures of the expression of myogenic (myogenin), regeneration (tenascin-C) and adipogenic markers (PPARG). Measurements were subjected to a (repeated) analysis of variance (ANOVA) with post hoc test of Fisher to identify statistically significant effects.