Allogeneic adipose-derived mesenchymal stem cells promote the expression of chondrocyte redifferentiation markers and retard the progression of knee osteoarthritis in rabbits.

Osteoarthritis (OA) is a progressively degenerative disease of joints. In vitro culture of chondrocytes results in dedifferentiation, which is characterized by the development of fibroblast phenotypes, reduced ability to produce cartilage extracellular matrix (ECM) and increase the expression of molecular markers Col1a1, Col10a1 and Runx2. Redifferentiation of chondrocytes is indicated by increased expression of the molecular markers Col2a1, Aggrecan and Sox9. In the current study, we investigated the effects of allogeneic rabbit adipose-derived mesenchymal stem cells (ADSCs) on articular chondrocytes, and explored the therapeutic effect of ADSCs on damaged articular cartilage at different stages in a rabbit OA model. In vitro , the proliferation and migration of primary articular chondrocytes were enhanced by cocultured rabbit ADSCs, and the expression of redifferentiation markers in chondrocytes cocultured with ADSCs was increased at both the mRNA and protein levels, while the expression of dedifferentiation markers was decreased. In vivo , the rabbit model of OA was established by anterior cruciate ligament transection (ACLT) with complete medial meniscectomy (MMx). Two weeks after surgery, ADSCs were used for OA rabbit treatment. Intra-articular injection of ADSCs gradually alleviated articular cartilage destruction, decreased Osteoarthritis Research Society International (OARSI) and Mankin scores, and reduced MMP13 expression at different stages in the rabbit model of OA. During the experiment, allogeneic ADSCs did not cause any adverse events. The current study demonstrates the effects and molecular mechanisms of ADSCs on articular chondrocytes and provides a favorable reference for clinical OA treatment with mesenchymal stem cells (MSCs) derived from adipose tissue.