Osteoarthritis (OA) is a prevalent whole joint disease characterised by cartilage degradation, subchondral bone sclerosis and bone remodelling, and synovium inflammation, leading to pain, deformity, and cartilage dysfunction. Currently, there is no appropriate therapy for OA, and available treatments simply aim to reduce pain and swelling. Exosomes are membrane-bound extracellular vesicles secreted by almost all cells, receiving increasing interest because of their effect in cell-to-cell communication. Increasing evidence suggests that exosomes play an important role in cartilage physiological and pathological effects. Researchers from the Queensland University of Technology discuss the potential role of exosomes in OA regenerative medicine. Special attention is given to mesenchymal stem cells-derived exosomes due to the extensive research on their cartilage repair property and their function as miRNA cargo. More investigations are needed for the effects of exosomes from synovial fluid and chondrocytes in joints. A better understanding of the mechanisms will contribute to a novel and promising therapy for OA patients.
FLS-derived exosomes induce the gene expression patterns related to OA
Exosomes secreted by IL-1β-stimulated FLS promote MMP-13 and TNF-α expression while inhibiting ACAN and COL2A1 expression. MMP-13 is the most important collagenase that causes type Ⅱ collagen degradation. The upregulation or aberrant activation of MMP-13 contributes to the progression of different stages of OA. TNF-α is also involved in the cartilage degradation process. Simultaneously, the expression of anabolic genes (ACAN and COL2A1) is decreased.