Acetazolamide protects rat articular chondrocytes from IL-1β-induced apoptosis by inhibiting the activation of NF-κB signal pathway

Because the excessive apoptosis of articular chondrocytes contributes to extracellular matrix (ECM) loss and cartilage damage in rheumatoid arthritis (RA), inhibiting chondrocyte apoptosis might be a promising strategy for RA. Aquaporin1 (AQP1) is overexpressed in RA cartilage and synovial tissues, and play a vital pathogenic role in RA development. Particularly, we previously reported that acetazolamide (AZ) as an AQP1 inhibitor suppressed secondary inflammation and promoted ECM production in cartilage of adjuvant-induced arthritis rats. Here, we investigated the antiapoptotic effect of AZ on interleukin-1 beta (IL-1 beta)-induced apoptosis, a classic in vitro model of chondrocyte apoptosis. AZ treatment could inhibit IL-1 beta-induced apoptosis, evidenced by increasing cell viability, relieving apoptotic nuclear morphology, decreasing apoptosis rates, and restoring mitochondrial membrane potential. Additionally, AZ reversed IL-1 beta-induced decrease of Bcl-2 protein and reduced IL-1 beta-induced increases of Bax and caspase 3 protein, accompanied by inhibiting I kappa B alpha degradation and phosphorylation in cytoplasm, reducing NF-kappa B p65 protein level in nucleus and preventing NF-kappa B p65 translocation from cytoplasm to nucleus. In conclusion, our findings indicated that AZ could effectively attenuate IL-1 beta-induced chondrocyte apoptosis mediated by regulating the protein levels of apoptosis-related genes and inhibiting the activation of NF-kappa B signal pathway, suggesting that AZ might be of potential clinical interest in RA treatment.