Taurine attenuates arsenic-induced pyroptosis and nonalcoholic steatohepatitis by inhibiting the autophagic-inflammasomal pathway

Arsenic exposure causes nonalcoholic steatohepatitis (NASH). Inflammation is a key contributor to the pathology of nonalcoholic fatty liver disease (NAFLD), including NASH. However, it is unclear how arsenic induces inflammation. In mouse livers, we show that arsenic trioxide (As₂O₃) induced NASH, increased Autophagy and NLRP3 inflammasome activation, increased lipid accumulation, and resulted in dysregulation of lipid-related genes. Supplemented with taurine (Tau) attenuated the inflammation and Autophagy caused by As₂O₃. In HepG2 cells, we found that As₂O₃-induced pyroptotic cell death was dependent upon the activation of NLRP3 inflammasome, which was CTSB-dependent. In addition, inhibiting Autophagy alleviated the As₂O₃-induced increase of cytosolic CTSB expression and subsequent release of LDH, activation of the NLRP3 inflammasome, and Pyroptosis. Moreover, we found that Tau alleviated As₂O₃-induced elevation of Autophagy, CTSB expression, and activation of the NLRP3 inflammasome, and reduced the release of LDH, pyroptotic cell death, and inflammation. Interestingly, As₂O₃-induced lipid accumulation could not be alleviated by either inhibition of Autophagy nor by inhibition of CTSB. Additionally, neither inhibition of the NLRP3 inflammasome or Tau treatment could alleviate lipid accumulation. These results demonstrated that As₂O₃-induced Pyroptosis involves Autophagy, CTSB, and the NLRP3 inflammasome cascade, and that Tau alleviates As₂O₃-induced liver inflammation by inhibiting the autophagic-CTSB-NLRP3 inflammasomal pathway rather than decreasing lipid accumulation. These findings give insight into the association of Autophagy, inflammation, Pyroptosis, and NASH induced by As₂O₃.