Fig. 5

NFKB1 and NR3C1 are the core transcriptional factors of MAPK4 in ALI. a Methylation levels of CpG sites in MAPK4 promoter were detected in control lungs (n = 6) and ALI lungs (n = 6). b Series truncated versions of MAPK4 promoter (-2021 bp to + 173 bp) were synthesized and cloned into the luciferase reporter vector pGL3.0 basic. c The truncated versions of MAPK4 promoter were transfected into RAW264.7 cells and the relative luciferase activity were measured (n = 6). d, e The candidate transcriptional factors, including Sp1, Egr-1, NFKB1, PU.1 and NR3C1 were screened by TRANSFAC and JASPAP database. f The mRNA levels of relative candidate transcriptional factors, including PU.1, NFKB1, NR3C1, Egr-1 and Sp1, were detected in lung tissues by Real-time PCR assay (n = 5–6). g The protein levels of NFKB1 and NR3C1 were analyzed in lung tissues by Western blot. h, i EMSA assay shows DNA–protein interaction of transcriptional factors NFKB1 and NR3C1 to the MAPK4 promoter in vitro. Data were presented as the mean ± SEM. *p < 0.05, **p < 0.01