title: Isolation and characterization of human amniotic mesenchymal stem cells and their chondrogenic differentiation.
abstract: BACKGROUND
  Freshly isolated human amniotic mesenchymal (fHAM) cells contain somatic stem cells possessing proliferative ability and pluripotency, including a chondrogenic lineage. However, little is known about the biology of amnion-derived mesenchymal stem cells (MSCs) because fHAM cells can barely survive to expand under culture conditions in vitro for a long time.
  
  
  METHODS
  In this study, we separated fHAM cells and seeded them to isolate MSCs and analyze its character. In addition, suitable chondrogenic growth factor was determined by pellet culture, and their viability under xenogenic environment was examined by transplantation into rabbit knee joints.
  
  
  RESULTS
  We succeeded in purifying proliferative subpopulations of fHAM cells, which could continue to proliferate more than 50 cumulative population doubling levels, and designated them as HAMα cells. Flow cytometry analysis revealed that they were positive for MSC markers (CD44, CD73, CD90, and CD105) and negative for hematopoietic cell markers (CD34, CD14, and CD45) and major histocompatibility complex class II antigen (human leukocyte antigen-DR). The expression of various stem-cell markers such as OCT3/4, C-MYC, SOX2, NANOG, CD44, SSEA-3, and SSEA-4 was also proved by immunocytochemical staining. Pellet culture using chondrogenic medium supplemented with transforming growth factor β3, transforming growth factor β3 plus bone morphogenetic protein (BMP)-2, or BMP-2 implied that supplementation of BMP-2 alone most effectively induced chondrogenesis in vitro. Xenotransplantation of HAMα cells achieved 8-week survival in vivo.
  
  
  CONCLUSIONS
  These results suggest that HAMα cells correspond to MSCs that are highly proliferative and multipotent. Their chondrogenic potential and low immunogenicity indicate that HAMα cells could be an allotransplantable cell resource for cartilage repair.
authors: Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
authors: Makiko
authors: M
authors: Nogami
authors: Hiroaki
authors: H
authors: Tsuno
authors: Chika
authors: C
authors: Koike
authors: Motonori
authors: M
authors: Okabe
authors: Toshiko
authors: T
authors: Yoshida
authors: Shoji
authors: S
authors: Seki
authors: Yoshito
authors: Y
authors: Matsui
authors: Tomoatsu
authors: T
authors: Kimura
authors: Toshio
authors: T
authors: Nikaido
mesh_terms: D000650:Amnion / Q000166:cytology*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D002358:Cartilage, Articular / Q000601:surgery; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D002469:Cell Separation / Q000379:methods; D002470:Cell Survival / Q000502:physiology; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D011247:Pregnancy; D011817:Rabbits; D053782:Transforming Growth Factor beta3 / Q000378:metabolism; D014183:Transplantation, Heterologous
chemical_list: C525718:BMP2 protein, human; D015415:Biomarkers; D055396:Bone Morphogenetic Protein 2; D053782:Transforming Growth Factor beta3