Chondrocytes-derived exosomal miR-8485 regulated the Wnt/β-catenin pathways to promote chondrogenic differentiation of BMSCs

In indirect co-culture system, chondrocytes can induce differentiation of bone marrow mesenchymal stem cells (BMSCs) to chondrocytes without additional inducer. The participation of microRNAs (miRNAs) may take part in the chondrogenic differentiation. Present study aimed to investigate the effect and mechanism of chondrocytes-derived exosomal miRNA in BMSCs chondrogenic differentiation. Our data showed that miR-8485 was the exosomal miRNA derived from chondrocytes and transmitted to BMSCs. Functionally, miR-8485 silence in chondrocytes impaired exosome-induced chondrogenic differentiation of BMSCs. Mechanistically, exosomal miR-8485 targeted GSK3B to repress GSK-3β expression and targeted DACT1 to induce p-GSK-3β (Ser9), activating Wnt/β-catenin pathways. Our study firstly showed that chondrocytes-derived exosomal miR-8485 regulated the Wnt/β-catenin pathways to promote chondrogenic differentiation of BMSCs, providing innovative thoughts for cartilage reconstruction.