Deficiency of STAT6 impaired the antioxidant capacity of lung tissues by downregulating Nrf2 signaling. (a) The mRNA expressions of Nrf2, GCS, and NQO1 in lung tissues were detected by qRT-PCR. Results were expressed as means ± SD (n = 6, ∗P < 0.05, Stat6+/+ vs. Stat6−/−). (b) The protein expression levels of Nrf2 and NQO1 in lung tissues were determined by western blot analysis in the indicated group. Results were presented as means ± SD (n = 6, ∗P < 0.05, Ctrl vs. particle; #P < 0.05, Stat6+/+ vs. Stat6−/−). (c) The protein expressions of STAT6, Nrf2, and NQO1 in BEAS-2B cells treated with siCtrl or indicated doses of siSTAT6 were measured using western blot analysis. Results were expressed as means ± SD (n = 4; ∗P < 0.05, Ctrl vs. treatment groups). (d) Immunofluorescence staining of Nrf2 in the cells with transfection of STAT6 plasmid or vector. Nuclei were stained with DAPI (blue). (e) Relative MDA and (f) GSH levels in lung tissue were measured. Results were expressed as means ± SD (n = 6, ∗P < 0.05, Ctrl vs. particle; #P < 0.05, Stat6+/+ vs. Stat6−/−).