Kallistatin attenuates inflammatory response in rheumatoid arthritis via the NF-κB signaling pathway

Cartilage degeneration and inflammation are important features of rheumatoid arthritis (RA). Chondrocyte inflammation and apoptosis have been increasingly demonstrated to be related to cartilage decomposition. In this study, we analyzed the protective role of kallistatin against RA and its associated mechanisms. We obtained in vitro and in vivo RA models using IL-1β and heat-inactivated Mycobacterium tuberculosis, respectively. Our results showed that kallistatin mitigated IL-1β-mediated chondrocyte apoptosis and inhibited the synthesis of ECM-degrading generation, like matrix metalloproteinase (MMP)-3/13 and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4/5, in IL-1β-mediated chondrocytes. Furthermore, kallistatin markedly suppressed IL-1β-mediated inflammation while decreasing the levels of inflammatory factors and mediators via the NF-κB pathway. Daily administration of kallistatin reduced the expression levels of PGE2, TNF-α, IL-1β, and IL-6. Histochemical analysis revealed that the kallistatin-treated rats exhibited reduced RA severity compared with control mice. In summary, kallistatin suppressed IL-1β-mediated inflammation in chondrocytes via the NF-κB pathway. Administration of kallistatin remarkably inhibited RA development, accompanied by reduced inflammation and apoptosis. Therefore, kallistatin administration can be used as a candidate therapeutic strategy for RA.