title: Analysis of the chondrogenic potential of human synovial stem cells according to harvest site and culture parameters in knees with medial compartment osteoarthritis.
abstract: OBJECTIVE
  Synovial mesenchymal stem cells (MSCs) are an attractive cell source for cartilage regeneration because of their high chondrogenic ability. In this study, we examined the synovium of patients with medial compartment knee osteoarthritis (OA) to determine the proportion of MSCs in relation to cellular compartmentalization, and to identify the culture parameters that could affect the chondrogenic potential of synovial MSCs.
  
  
  METHODS
  Human synovium was collected from 4 different harvest sites in the knees of patients with medial compartment OA. Each synovial tissue sample was divided into 2 parts, one for histologic assessment and the other for analysis of the cell size, surface epitopes, and chondrogenic potential of colony-forming cells in vitro.
  
  
  RESULTS
  The numbers of alpha-smooth muscle actin-positive vessels and CD31+ endothelial cells were higher in the medial outer region than in the other regions of OA synovial tissue. The numbers of these cells correlated with the number of colony-forming cells. In parallel with increasing duration of the preculture period, the size of the cells increased, while the chondrogenic potential decreased, and this was correlated with expression of CD90.
  
  
  CONCLUSIONS
  Medial compartment knee OA demonstrates variability in the distribution of vessels, which results in a varying distribution of MSCs. The preculture period should be utilized to assess both the potential for expansion and the chondrogenic potential of MSCs.
authors.affiliation: Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nagase
authors.forename: Takeshi
authors.initials: T
authors.lastname: Muneta
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Ju
authors.forename: Kenji
authors.initials: K
authors.lastname: Hara
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Morito
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Koga
authors.forename: Akimoto
authors.initials: A
authors.lastname: Nimura
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Mochizuki
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sekiya
mesh_terms: D018929:Cell Culture Techniques; D002478:Cells, Cultured; D020219:Chondrogenesis; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D020370:Osteoarthritis, Knee / Q000473:pathology*; D013234:Stem Cells; D013583:Synovial Membrane / Q000166:cytology*; D020858:Tissue and Organ Harvesting