Isolation and identification of stem cells in different subtype of cartilage tissue

Background: Cartilage tissue engineering provided a promising therapy for the repair of cartilage defects, and seeding cells play a vital role in cartilage regeneration. Chondrocytes and bone marrow-derived mesenchymal stem cells (BMSCs) were reported to be the ideal seeding cells, but 'dedifferentiation' and 'unstable phenotype' of tissue-engineered cartilage constructed by the two cell type hamper their clinical application. Recently, cartilage tissue was reported to possess a stem cell population, which may be a more superior cell source in cartilage tissue engineering. Methods: In current study, we isolated a cell population from different subtype of cartilage tissue via a differential adhesion assay to fibronectin. Results: Flow cytometry analysis demonstrates the cell lines expressed mesenchyme stem cell positive surface marker such as CD29 and CD90. Meanwhile, the cells are highly proliferative and multipotent. Reverse transcription-PCR detection showed the cell population expressed osteogenic and adipogenic differentiation under different induction conditions. More interesting, monolayer cells underwent chondrogenic differentiation in the presence of dexamethasone and insulin-like growth factor 1. In addition, the expression of chondrogenic genes in cartilage-derived stem cells (CSCs) was higher than those in BMSCs. Conclusion: CSC may become an ideal seeding cell in cartilage tissue engineering, owing to its stemness and chondrogenic characteristics.