title: Expression of CD105 on expanded mesenchymal stem cells does not predict their chondrogenic potential.
abstract: OBJECTIVE
  Total bone marrow-derived mesenchymal stem cell (BMSC) populations differ in their potential to undergo chondrogenesis, with individual BMSCs differing in their chondrogenic capacity. The aim of this study was to explore the use of CD105 as a marker to isolate a chondrogenic subpopulation of BMSCs from the total, heterogeneous population.
  
  
  METHODS
  BMSCs were isolated from patients undergoing total hip replacement and following expansion (Passage 1-Passage 5), CD105 expression was investigated by FACS analysis. FACS was also used to sort BMSCs based on the presence of CD105 (CD105(+)/CD105(-)) or their amount of CD105 expression (CD105(Bright)/CD105(Dim)). After 3 or 5 weeks of differentiation, chondrogenic potential was determined by thionine staining for glycosaminoglycan (GAG) content and by detection of collagen type II using immunohistochemistry.
  
  
  RESULTS
  Expanded total BMSC populations were composed almost exclusively of CD105(+) cells, the percentage of which did not correlate to subsequent chondrogenic potential; chondrogenic potential was observed to diminish with culture although CD105 expression remained stable. Similarly, differences in chondrogenic potential were observed between donors despite similar levels of CD105(+) BMSCs. Comparison of CD105(Bright) and CD105(Dim) BMSCs did not reveal a subpopulation with superior chondrogenic potential.
  
  
  CONCLUSIONS
  Chondrogenic potential of BMSCs is often linked to CD105 expression. This study demonstrates that CD105 expression on culture expanded BMSC populations does not associate with a chondroprogenitor phenotype and CD105 should not be pursued as a marker to obtain a chondroprogenitor population from BMSCs.
authors.affiliation: School of Veterinary Medicine, Veterinary Science Centre, University College Dublin, Belfield, Dublin 4, Ireland; Department of Orthopaedics, Erasmus MC, University Medical Centre, 3015 CN Rotterdam, The Netherlands. Electronic address: mairead.cleary@ucdconnect.ie.
authors.forename: M A
authors.initials: MA
authors.lastname: Cleary
authors.affiliation: Department of Orthopaedics, Erasmus MC, University Medical Centre, 3015 CN Rotterdam, The Netherlands. Electronic address: r.narcisi@erasmusmc.nl.
authors.forename: R
authors.initials: R
authors.lastname: Narcisi
authors.affiliation: Department of Orthopaedics, Erasmus MC, University Medical Centre, 3015 CN Rotterdam, The Netherlands. Electronic address: kristin2911@gmx.de.
authors.forename: K
authors.initials: K
authors.lastname: Focke
authors.affiliation: Erasmus MC Stem Cell and Regenerative Medicine Institute, Department of Cell Biology, Erasmus MC, University Medical Centre, 3015 CN Rotterdam, The Netherlands. Electronic address: r.linden@hubrecht.eu.
authors.forename: R
authors.initials: R
authors.lastname: van der Linden
authors.affiliation: School of Veterinary Medicine, Veterinary Science Centre, University College Dublin, Belfield, Dublin 4, Ireland. Electronic address: pieter.brama@ucd.ie.
authors.forename: P A J
authors.initials: PA
authors.lastname: Brama
authors.affiliation: Department of Orthopaedics, Erasmus MC, University Medical Centre, 3015 CN Rotterdam, The Netherlands; Department of Otorhinolaryngology, Erasmus MC, University Medical Centre, 3015 CN Rotterdam, The Netherlands. Electronic address: g.vanosch@erasmusmc.nl.
authors.forename: G J V M
authors.initials: GJ
authors.lastname: van Osch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism; D020219:Chondrogenesis / Q000502:physiology*; D000071063:Endoglin / Q000378:metabolism*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D008875:Middle Aged
chemical_list: D015415:Biomarkers; C064206:ENG protein, human; D000071063:Endoglin
keywords: CD105; Chondrogenesis; Chondroprogenitor; Mesenchymal stem cells; Subpopulation