title: Behaviour of human physeal chondro-progenitorcells in early growth plate injury response in vitro.
abstract: OBJECTIVE
  The aim of this study was to investigate the proliferation and differentiation behaviour of a defined cell population gained from the human growth plate, namely, chondro-progenitorcells (CPCs), in the initial inflammatory phase of growth plate injury response in vitro.
  
  
  METHODS
  Growth plate cells were sorted via FACS and differentiated along adipogenic and osteogenic lineage to confirm their progenitor features. To mimic the inflammatory phase of injury response at the growth plate they were treated with IL-1β and exposed to cyclic mechanical loading. A BrdU assay was used to investigate CPC proliferation. CPC differentiation behaviour was analysed by RT-PCR.
  
  
  RESULTS
  CPCs (CD45-, CD34-, CD73+, CD90+, and CD105+) showed a successful differentiation along adipogenic and osteogenic lineage. Under conditions simulating the inflammatory phase of injury response at the growth plate in vitro CPCs differentiated towards hypertrophy while chondrogenesis and ossification were inhibited. Proliferation was not significantly altered.
  
  
  CONCLUSIONS
  This study showed that CPCs can be isolated from the human growth plate and expanded in vitro. In the first phase of injury response at the growth plate these cells differentiate towards hypertrophy. As longitudinal growth is obtained by chondrocyte proliferation and volume increase during hypertrophy this maturation might be the first step towards post-traumatic growth disorders such as unwanted premature ossification of the growth plate.
authors.affiliation: Department of Pediatric and Adolescent Surgery, Medical University Graz, Auenbruggerplatz 34, 8036 Graz, Austria. karin.pichler@medunigraz.at
authors.forename: Karin
authors.initials: K
authors.lastname: Pichler
authors.forename: Barbara
authors.initials: B
authors.lastname: Schmidt
authors.forename: Eva E
authors.initials: EE
authors.lastname: Fischerauer
authors.forename: Beate
authors.initials: B
authors.lastname: Rinner
authors.forename: Gottfried
authors.initials: G
authors.lastname: Dohr
authors.forename: Andreas
authors.initials: A
authors.lastname: Leithner
authors.forename: Annelie M
authors.initials: AM
authors.lastname: Weinberg
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects; D049108:Cell Enlargement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002469:Cell Separation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000473:pathology* / Q000502:physiology; D020219:Chondrogenesis / Q000187:drug effects; D005434:Flow Cytometry; D006132:Growth Plate / Q000473:pathology*; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D009999:Ossification, Heterotopic / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology; D010011:Osteocytes / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D010012:Osteogenesis / Q000187:drug effects; D000072042:Salter-Harris Fractures; D013234:Stem Cells / Q000187:drug effects / Q000473:pathology* / Q000502:physiology; D013314:Stress, Mechanical; D016474:Weight-Bearing
chemical_list: D053583:Interleukin-1beta