title: Limited evidence of chondrocyte outgrowth from adult human articular cartilage.
abstract: OBJECTIVE
  Cellular outgrowth from articular cartilage tissue has been described in a number of recent experimental studies. The aim of this study was to investigate the occurrence of cellular outgrowth from articular cartilage explants isolated from adult human donors.
  
  
  METHODS
  Macroscopically intact articular cartilage specimens were isolated from adult human donors and cultured either in their native status, or in a cleansed status achieved by forced washing to minimize attaching cells. Additionally, the effect of chemotactic stimuli including cell lysate, High-Mobility-Group-Protein B1 (HMGB-1), Trefoil-factor 3 (TFF3), bone morphogenetic protein-2 (BMP-2), transforming growth factor-ß1 (TGF-ß1), or three-dimensional fibrin or collagen matrices were investigated. Co-cultures with synovial membrane served as a positive control for a source of migratory cells. The occurrence of cellular outgrowth was analyzed by histological examination after a culture period of 4 weeks.
  
  
  RESULTS
  Spontaneous cellular outgrowth from cleansed cartilage specimens was not observed at a relevant level and could not significantly be induced by chemotactic stimuli or three-dimensional matrices either. A forming cartilage-adjoining cell layer was only apparent in the case of native cartilage explants with cellular remnants from surgical isolation or in co-culture experiments with synovial membrane.
  
  
  CONCLUSIONS
  The relevance of cellular outgrowth from cartilage tissue is largely absent in the case of adult human articular cartilage samples. A cartilage-adjoining cell layer forming around the explants may instead originate from still attaching cells that remained from surgical isolation.
authors.affiliation: Dept. of Orthopaedic and Trauma Surgery, University Hospital Erlangen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Zingler
authors.affiliation: Dept. of Orthopaedic Rheumatology, University of Erlangen-Nuremberg, Germany.
authors.forename: H-D
authors.initials: HD
authors.lastname: Carl
authors.affiliation: Dept. of Orthopaedic Rheumatology, University of Erlangen-Nuremberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Swoboda
authors.affiliation: Dept. of Orthopaedic and Trauma Surgery, University Hospital Erlangen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Krinner
authors.affiliation: Dept. of Orthopaedic and Trauma Surgery, University Hospital Erlangen, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Hennig
authors.affiliation: Dept. of Orthopaedic and Trauma Surgery, University Hospital Erlangen, Germany. Electronic address: kolja.gelse@web.de.
authors.forename: K
authors.initials: K
authors.lastname: Gelse
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D002358:Cartilage, Articular / Q000187:drug effects* / Q000502:physiology; D002633:Chemotaxis / Q000187:drug effects* / Q000502:physiology; D019902:Chondrocytes / Q000187:drug effects* / Q000502:physiology; D018920:Coculture Techniques; D003094:Collagen; D005337:Fibrin; D024243:HMGB1 Protein / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D010455:Peptides / Q000494:pharmacology*; D012038:Regeneration / Q000187:drug effects* / Q000502:physiology; D013583:Synovial Membrane; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*; D000071165:Trefoil Factor-3
chemical_list: D055396:Bone Morphogenetic Protein 2; D024243:HMGB1 Protein; D010455:Peptides; C082495:TFF3 protein, human; D053773:Transforming Growth Factor beta1; D000071165:Trefoil Factor-3; D005337:Fibrin; D003094:Collagen
keywords: Cartilage regeneration; Chemotaxis; Explant model; Migration