Detection of the PP2A and cell pyroptosis-related indicators by Western blot analysis demonstrated that upon HDAC1 overexpression or PP2A silencing in the PU treated ALI mice, the expression of PP2A was reduced and the expression of NLRP3, pro-IL-1β, and Caspase-1 p20 protein were increased, while the expression of Caspase-1 presented no significant changes (Fig. 5E, Supplementary Fig. 1D). Here, CASP1 is linked to acute respiratory distress syndrome.