Effects of Oxysterols on Chondrogenesis of Human Adipose-derived Stem Cells

Human adipose-derived stem cells (hADSCs) have been implicated as a high potency source of chondrocytes in cell therapy for cartilage defects. However, appropriate stimulators for the chondrogenesis of hADSCs are needed. Oxysterols have the potential to act as a stimulator. This study aims to investigate the effect of oxysterols on the chondrogenesis of hADSCs. hADSCs were collected from the abdominal subcutaneous tissue samples of patients undergoing caesarean section, and were cultured to passage 5. Mesenchymal stem cell markers were examined by flow cytometry. After the cells were subjected to adipogenic, osteogenic, and chondrogenic induction, the differentiation of each cell lineage was evaluated by RT-PCR and specific staining (Oil red O, Alizarin red S, and Alcian blue, respectively). The cell pellets of hADSCs were cultured in chondrogenic induced media containing 2μM 22(R)-hydroxycholesterol, 22(S)-hydroxycholesterol, or 25-hydroxycholesterol for 4 weeks. At 3 and 4 weeks of culture, the size and wet weight of the pellets were measured. The expressions of chondrogenesis-related genes and glycosaminoglycans production were examined by quantitative real-time PCR and Alcian blue staining. hADSCs were positive for the mesenchymal markers CD75, CD90, and CD105, while being negative for the hematopoietic markers CD31, CD34 and CD45. The multilineage potential of hADSCs was confirmed by the expression of adipogenic-, osteogenic-, and chondrogenic-specific genes, along with specific staining. 22(R)-hydroxycholesterol treatment significantly increased the size and wet weight of the pellet, glycosaminoglycans production, and expression of chondrogenic-related genes compared to the control group and other oxysterols (P<0.05). These results indicate that 22(R)-hydroxycholesterol can be effective as a stimulator for the chondrogenesis of hADSCs.