Tributyltin chloride induces chondrocyte damage through the activation of NLRP3-mediated inflammation and pyroptosis

Tributyltin chloride (TBTC) is known to have effects and mechanisms in various diseases; however, whether TBTC is detrimental to joints and causes osteoarthritis (OA), as well as its underlying mechanism, has not yet been fully elucidated. The present study explored the effects of TBTC on rat chondrocytes, as well as on mouse OA. The toxicity of TBTC toward rat chondrocytes was detected using a lactate dehydrogenase (LDH) leakage assay and cell viability was evaluated using the Cell Counting Kit-8 assay. The results showed that TBTC decreased the viability of rat chondrocytes and increased the LDH leakage rate in a concentration-dependent manner. Moreover, compared with in the control group, TBTC increased the expression levels of interleukin (IL)-1 beta, IL-18, matrix metalloproteinase (MMP)-1, MMP-13, NLR family pyrin domain containing 3 (NLRP3), caspase-1, PYD and CARD domain containing, and gasdermin D in chondrocytes. Furthermore, knockdown of NLRP3 reversed the TBTC-induced increases in LDH leakage and NLRP3 inflammasome-associated protein levels. In vivo, TBTC exacerbated cartilage tissue damage in mice from the OA group, as evidenced by the attenuation of safranin O staining. In conclusion, TBTC may aggravate OA in mice by promoting chondrocyte damage and inducing pyroptosis through the activation of NLRP3 and caspase-1 signaling. The present study demonstrated that TBTC can cause significant damage to the articular cartilage; therefore, TBTC contamination should be strictly monitored.