title: In vitro chondrogenesis of the goat bone marrow mesenchymal stem cells directed by chondrocytes in monolayer and 3-dimetional indirect co-culture system.
abstract: BACKGROUND
  Cartilage injury has a very poor capacity for intrinsic regeneration. The cell-based treatment strategy for the cartilage repair using differentiated bone marrow mesenchymal stem cells (BMSCs) is, however, a promising approach to the chondral repair. This study was aimed to explore the chondrogenic potential of the goat BMSCs in the Transwell co-culture system and the poly-laetide-co-glycolide (PLGA) scaffolds.
  
  
  METHODS
  The BMSCs were isolated from the goat iliac crest while the chondrocytes were obtained from the goat's last costal cartilage. In the Transwell co-culture system, the BMSCs co-cultured with chondrocytes were designed as group A, whereas the goat's BMSCs induced with the chondrogenic medium were group B. Both groups A and B were the experimental groups, while group C that only contained BMSCs was the control group. In the PLGA scaffolds co-culture system, BMSCs were seeded into the PLGA scaffolds, which were suspended in the 24-well plate, and the control group was established by presence or absence of chondrocytes at the bottom of the 24-well plate. Toluidine blue staining, Alcian blue staining, collagen II immunofluoresence, collagen II immunochemical staining, collagen I, collagen II, COL2a Q-PCR and osteopontin Q-PCR were used to examine the chondrogenic conditions as well as the expressions of chondrogenic and osteogenic genes.
  
  
  RESULTS
  Cells isolated from the aspirates of the goat bone marrow proliferated rapidly and gained characteristics of stem cells in Passage 4. However, the differentiations of chondrocytes were not apparent in Passage 3. The results from Toluidine blue staining, collagen II immunofluoresence and PCR showed the transformation of BMSCs to chondrocytes in the Transwell co-culture system and PLGA scaffolds. Although the cartilage gene expressions were upgraded in both chondrogenesis group and co-culture system, the osteopontin gene expression, which represents osteogenic level, was also up-regulated.
  
  
  CONCLUSIONS
  The Transwell co-culture system and the PLGA scaffolds co-culture system can promote the chondrogenic differentiation of the goat's BMSCs, while up-regulated osteopontin gene expression in the Transwell co-culture system implies the osteogenic potential of BMSCs.
authors: Department of Traumatology and Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China.
authors: Jian-Wei
authors: JW
authors: Li
authors: Xiao-Lei
authors: XL
authors: Guo
authors: Chun-la
authors: CL
authors: He
authors: Yong-Hua
authors: YH
authors: Tuo
authors: Zhao
authors: Z
authors: Wang
authors: Jun
authors: J
authors: Wen
authors: Dan
authors: D
authors: Jin
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology*; D018929:Cell Culture Techniques / Q000379:methods; D019902:Chondrocytes / Q000502:physiology*; D020219:Chondrogenesis / Q000502:physiology*; D018920:Coculture Techniques; D006041:Goats; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds