Fig. 7
DNA methylation alters the binding of transcription factor Sp3 to the promoter of PLA2G7 and changes gene expression. a ChIP assay on the promoter of PLA2G7. The effect of 5-aza-CdR on Sp3 binds to the 5ʹ-flanking regions of PLA2G7. THP-1 cells were treated with 5-aza-CdR (25 μM, 48 h). ChIP assays were performed with the antibodies against Sp3 and IgG were used as a negative control. Three independent experiments were done with the similar results. Results from one experiment are shown. b qPCR of ChIP assay in (a). Precipitated DNA fragments were detected using qPCR with specific primers spanning the DNA segments containing the indicated Sp3 responsive element of PLA2G7 promoter. Three independent experiments were done with similar results, each with triple biological repeats. Data were from one experiment with three technical replicates. n = 3 different cell batches, means ± SD, Student’s t-test, *p < 0.05. c The level of Lp-PLA2 mRNA in THP-1 cell pretreated with LPS with or without (control) 5-aza-CdR (25 μM, 48 h). d The level of Lp-PLA2 activity in THP-1 cell pretreated with LPS with or without (control) 5-aza-CdR (25 μM, 48 h). For c and d n = 3 different cell batches, mean ± SME, Mann–Whitney U test, *p < 0.05. e The level of Lp-PLA2 mRNA in THP-1 cell pretreated with LPS in the presence (+) or absence (−) of 5-aza-CdR (25 μM, 48 h) and TSA (100 nM, 24 h). f The level of Lp-PLA2 activity in THP-1 cell pretreated with LPS in the presence (+) or absence (−) of 5-aza-CdR (25 μM, 48 h) and TSA (100 nM, 24 h). For e and f n = 3 different cell batches, mean ± SME, ANOVA with a post hoc Bonfferoni test. *p < 0.05. 5-aza-CdR, 5-aza-2'-deoxycytidine; Lp-PLA2, lipoprotein-associated phospholipase A2; ChIP, chromatin immunoprecipitation; LPS, lipopolysaccharide; and TSA, trichostatin A