| First Author | Matthews BG | Year | 2016 |
| Journal | Bone | Volume | 84 |
| Pages | 69-77 | PubMed ID | 26721734 |
| Mgi Jnum | J:329114 | Mgi Id | MGI:6869090 |
| Doi | 10.1016/j.bone.2015.12.010 | Citation | Matthews BG, et al. (2016) Osteogenic potential of alpha smooth muscle actin expressing muscle resident progenitor cells. Bone 84:69-77 |
| abstractText | Heterotopic ossification (HO) is a pathological process where bone forms in connective tissues such as skeletal muscle. Previous studies have suggested that muscle-resident non-myogenic mesenchymal progenitors are the likely source of osteoblasts and chondrocytes in HO. However, the previously identified markers of muscle-resident osteoprogenitors label up to half the osteoblasts within heterotopic lesions, suggesting other cell populations are involved. We have identified alpha smooth muscle actin (alphaSMA) as a marker of osteoprogenitor cells in bone and periodontium, and of osteo-chondro progenitors in the periosteum during fracture healing. We therefore utilized a lineage tracing approach to evaluate whether alphaSMACreERT2 identifies osteoprogenitors in the muscle. We show that in the muscle, alphaSMACreERT2 labels both perivascular cells, and satellite cells. alphaSMACre-labeled cells undergo osteogenic differentiation in vitro and form osteoblasts and chondrocytes in BMP2-induced HO in vivo. In contrast, Pax7CreERT2-labeled muscle satellite cells were restricted to myogenic differentiation in vitro, and rarely contributed to HO in vivo. Our data indicate that alphaSMACreERT2 labels a large proportion of osteoprogenitors in skeletal muscle, and therefore represents another marker of muscle-resident cells with osteogenic potential under HO-inducing stimulus. In contrast, muscle satellite cells make minimal contribution to bone formation in vivo. |
