ABSTRACT
BACKGROUND: Stem cell-based therapy has been proposed for the treatment of osteoarthritis (OA) and induced pluripotent stem cells (iPSCs) are becoming a promising stem cell source as they have strong proliferation and differentiation potentials and no ethics problem. OBJECTIVE: To explore an effective method of iPSCs differentiating into chondrocytes and to study the therapeutic effect of iPSCs derived chondrocytes on osteoarthritis. METHODS: In this study, three steps were developed to induce human iPSCs to differentiate into chondrocytes which were then transplanted into rat OA models induced by monosodium iodoacetate (MIA). There were four groups in the experiment: control group with normal saline injection, model group with MIA injection, iPSCs group with iPSCs transplantation following MIA injection, and differentiated iPSCs group with transplantation of iPSCs derived chondrocytes following MIA injection. At 15 weeks after transplantation, micro-CT was used and histological analysis of the knee joint was performed. RESULTS AND CONCLUSION: Compared with the iPS group, the expression of chondrocyte specific genes and proteins (Col2A1, GAG and Sox9) were significantly increased in the differentiated iPSCs group after 6 days of embryoid formation and after 2 weeks of cell differentiation. At 15 weeks after cell transplantation, no immune responses were observed, micro-CT showed an improvement in subchondral bone integrity, and histological examinations demonstrated the production of articular cartilage matrix. iPSCs derived chondrocytes showed better effects on articular cartilage repair than the iPSCs. To conclude, iPSCs derived chondrocytes can be effective via transplantation approach for cartilage tissue regeneration in OA rats.