title: Circulating osteogenic precursor cells in heterotopic bone formation.
abstract: Cells with osteogenic potential can be found in a variety of tissues. Here we show that circulating osteogenic precursor (COP) cells, a bone marrow-derived type I collagen+/CD45+ subpopulation of mononuclear adherent cells, are present in early preosseous fibroproliferative lesions in patients with fibrodysplasia ossificans progressiva (FOP) and nucleate heterotopic ossification (HO) in a murine in vivo implantation assay. Blood samples from patients with FOP with active episodes of HO contain significantly higher numbers of clonally derived COP cell colonies than patients with stable disease or unaffected individuals. The highest level of COP cells was found in a patient just before the clinical onset of an HO exacerbation. Our studies show that even COP cells derived from an unaffected individual can contribute to HO in genetically susceptible host tissue. The possibility that circulating, hematopoietic-derived cells with osteogenic potential can seed inflammatory sites has tremendous implications and, to our knowledge, represents the first example of their involvement in clinical HO. Thus, bone formation is not limited to cells of the mesenchymal lineage, and circulating cells of hematopoietic origin can also serve as osteogenic precursors at remote sites of tissue inflammation.
authors.affiliation: Department of Medicine, University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania 19104-6160, USA.
authors.forename: Robin K
authors.initials: RK
authors.lastname: Suda
authors.forename: Paul C
authors.initials: PC
authors.lastname: Billings
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Egan
authors.forename: Jung-Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Ruth
authors.initials: R
authors.lastname: McCarrick-Walmsley
authors.forename: David L
authors.initials: DL
authors.lastname: Glaser
authors.forename: David L
authors.initials: DL
authors.lastname: Porter
authors.forename: Eileen M
authors.initials: EM
authors.lastname: Shore
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Pignolo
mesh_terms: D000328:Adult; D000818:Animals; D016026:Bone Marrow Transplantation; D002460:Cell Line; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D009221:Myositis Ossificans / Q000378:metabolism / Q000473:pathology*; D009999:Ossification, Heterotopic / Q000378:metabolism / Q000473:pathology*; D010012:Osteogenesis / Q000502:physiology*