FIGURE 2.

MSC is involved in joint inflammation and cartilage repair through multiple mechanisms. MSC regulates immune cells (T cells, B cells, macrophages) by secreting paracrine factors (cytokines, growth factors and EVs), and intercellular contacts to exert immunomodulatory functions and reduce inflammation, such as inhibiting T and B cell proliferation and inducing macrophage polarization. MSC promotes chondrocyte proliferation, migration and anti‐apoptosis by secreting EVs, and inhibit chondrocyte inflammatory factor release and cartilage degradation by secreting paracrine factors and intercellular contacts.