Allogeneic human mesenchymal stem cells (MSC) as a novel therapy for OA
Osteoarthritis (OA) is a rheumatic disease leading to chronic pain and disability with no effective treatment available. Recently, allogeneic human mesenchymal stem cells (MSC) entered clinical trials as a novel therapy for OA. Increasing evidence suggests that therapeutic efficacy of MSC depends on paracrine signaling. Here we investigated the role of extracellular vesicles (EVs) secreted by human bone marrow-derived MSC (BMMSC) in human OA cartilage repair. We show that BMMSC-EVs inhibit the adverse effects of inflammatory mediators on cartilage homeostasis. BMMSC-EVs also promoted cartilage regeneration in vitro. Addition of BMMSC-EVs to cultures of chondrocytes isolated from OA patients stimulated production of proteoglycans and type II collagen by these cells. These data demonstrate that BMMSC-EVs can be important mediators of cartilage repair and hold great promise as a novel therapeutic for cartilage regeneration and osteoarthritis.