title: Differential marker expression by cultures rich in mesenchymal stem cells.
abstract: BACKGROUND
  Mesenchymal stem cells have properties that make them amenable to therapeutic use. However, the acceptance of mesenchymal stem cells in clinical practice requires standardized techniques for their specific isolation. To date, there are no conclusive marker (s) for the exclusive isolation of mesenchymal stem cells. Our aim was to identify markers differentially expressed between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. We compared and contrasted the phenotype of tissue cultures in which mesenchymal stem cells are rich and rare. By initially assessing mesenchymal stem cell differentiation, we established that bone marrow and breast adipose cultures are rich in mesenchymal stem cells while, in our hands, foreskin fibroblast and olfactory tissue cultures contain rare mesenchymal stem cells. In particular, olfactory tissue cells represent non-stem cell mesenchymal cells. Subsequently, the phenotype of the tissue cultures were thoroughly assessed using immuno-fluorescence, flow-cytometry, proteomics, antibody arrays and qPCR.
  
  
  RESULTS
  Our analysis revealed that all tissue cultures, regardless of differentiation potential, demonstrated remarkably similar phenotypes. Importantly, it was also observed that common mesenchymal stem cell markers, and fibroblast-associated markers, do not discriminate between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. Examination and comparison of the phenotypes of mesenchymal stem cell and non-stem cell mesenchymal cell cultures revealed three differentially expressed markers - CD24, CD108 and CD40.
  
  
  CONCLUSIONS
  We indicate the importance of establishing differential marker expression between mesenchymal stem cells and non-stem cell mesenchymal cells in order to determine stem cell specific markers.
authors.affiliation: Stem Cell & Tissue Re-engineering Program, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Kingdom of Saudi Arabia. drcna@aol.com.
authors.forename: Andrew
authors.initials: A
authors.lastname: Wetzig
authors.forename: Ayodele
authors.initials: A
authors.lastname: Alaiya
authors.forename: Monther
authors.initials: M
authors.lastname: Al-Alwan
authors.forename: Christian Benedict
authors.initials: CB
authors.lastname: Pradez
authors.forename: Manogaran S
authors.initials: MS
authors.lastname: Pulicat
authors.forename: Amer
authors.initials: A
authors.lastname: Al-Mazrou
authors.forename: Zakia
authors.initials: Z
authors.lastname: Shinwari
authors.forename: Ghida Majed
authors.initials: GM
authors.lastname: Sleiman
authors.forename: Hazem
authors.initials: H
authors.lastname: Ghebeh
authors.forename: Hind
authors.initials: H
authors.lastname: Al-Humaidan
authors.forename: Ameera
authors.initials: A
authors.lastname: Gaafar
authors.forename: Imaduddin
authors.initials: I
authors.lastname: Kanaan
authors.forename: Chaker
authors.initials: C
authors.lastname: Adra
mesh_terms: D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism*; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D051927:CD24 Antigen / Q000235:genetics / Q000378:metabolism; D019013:CD40 Antigens / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D052816:Foreskin / Q000166:cytology / Q000378:metabolism*; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D042361:Mammary Glands, Human / Q000166:cytology / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D039961:Semaphorins / Q000235:genetics / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D051927:CD24 Antigen; D019013:CD40 Antigens; D058851:GPI-Linked Proteins; C118753:SEMA7A protein, human; D039961:Semaphorins