Fig. 6

Schematic suggestion of the pathological changes of mCPCs in the progression of OA. In the progressing of OA, more mCPCs migrated into the articular cartilages for tissue repairing. However, the chondrogenerative capacities of mCPCs in grade 3–4 OA cartilage are remarkably impaired. Compared to their counterpart in grade 1–2 OA cartilage, these cells exhibited stronger osteogenesis, stronger adipogenesis, and weaker chondrogenesis