1,4-benzoquinone triggers pyroptosis and contributes to haematotoxicity via regulating the NLRP3/Caspase-1/GSDMD pathway.

[BACKGROUND] Benzene is a prevalent and potent carcinogenic air pollutant that poses significant risks to the hematopoietic system, even at low-level exposure. Although the blood toxicity of benzene has been widely confirmed, the potential molecular mechanisms of benzene poisoning have not yet been elucidated.

[METHODS] In this study, we established an in vitro injury model by treating human chronic myeloid leukemia K562 cells with 1,4-benzoquinone (1,4-BQ), the primary toxic metabolite of benzene. We utilized molecular biology experimental methods such as immunofluorescence, qRT PCR, and Western blotting to quantitatively detect the expression levels of NLRP3, caspase-1, GSDMD, and related inflammatory cytokines. Furthermore, we evaluated the protective effect of MCC950 by detecting changes in the expression levels of various key proteins after intervention with NLRP3 specific inhibitor MCC950, elucidating the molecular regulatory pathway of benzene induced pyroptosis toxicity, and identifying early biomarkers of benzene toxicity.

[RESULTS] 1,4-BQ induced a dose-dependent and time-dependent reduction in K562 cell viability, accompanied by statistically significant increase in lactate dehydrogenase (LDH) release and morphological features characteristic of pyroptosis, such as cell swelling and membrane rupture. Exposure to 1,4-BQ markedly upregulated the expression of the NLRP3 inflammasome, activated caspase-1, and the N-terminal fragment of GSDMD. This was consistent with an increased release of pro-inflammatory cytokines (IL-1β and IL-18) and a decrease in the anti-inflammatory cytokine IL-10. Notably, intervention with MCC950 significantly attenuated these pyroptotic markers and mitigated the inflammatory response.

[CONCLUSION] Our findings demonstrate that benzene metabolites trigger cell pyroptosis via the canonical NLRP3/Caspase-1/GSDMD signaling pathway, which also enhances and enriches the molecular regulatory network of benzene induced hematopoietic toxicity In addition, we found that targeting NLRP3 may provide a promising prevention and treatment strategy for benzene induced hematopoietic injury, and provide potential molecular targets for the development of preventive drugs and early intervention agents for benzene poisoning, which has important research significance.