Fig. 6
PLA2G7, a hypomethylated gene with increased expression in SYM and ASYM plaques. a t-SNE analysis diagram of PLA2G7. Red nodes represent SYM plaque samples (n = 6), blue nodes represent ASYM plaque samples (n = 8), and green nodes represent LIMA samples (n = 4). The node size represents the methylation level of PLA2G7. b The relative fold of the mRNA level of Lp-PLA2 in SYM plaques, ASYM plaques, and LIMAs (n = 6 for SYM plaques, n = 8 for ASYM plaques, and n = 4 for LIMAs, mean ± SD, ANOVA with a post hoc Bonfferoni test, *p < 0.05). c PLA2G7 is composed of twelve exons (blue). The locations of the CpG islands in the promoter region relative to PLA2G7 are shown according to the UCSC genome browser data (green). Six sites were found differentially methylated in the promoter region. Red highlights indicate one of the most significantly hypomethylated sites in plaques. d CpG plot of human PLA2G7 gene illustrating the putative CpG islands in the promoter region. THP-1 cells was treated with LPS. Bisulfite sequencing of the promoter region was performed to detect the methylation status by DMSO (control) and methyltransferase inhibitor 5-aza-CdR (25 μM, 48 h, n = 3 different cell batches). The CpG dinucleotides are highlighted in black. The red box indicates significant methylation differences in site cg11874627. e DNA methylation of PLA2G7 in THP-1 cells treated with LPS can be reversed by 5-aza-CdR. Bisulfite sequencing of the promoter region was performed to detect the methylation status by DMSO and methyltransferase inhibitor 5-aza-CdR (25 μM, 48 h, n = 3 different cell batches). A schematic diagram of the PLA2G7 promoter is presented to display the CG dinucleotide methylation percentage and relative position. The node represents the status of methylation. The red box indicates significant methylation differences site cg11874627. SYM, symptomatic; ASYM, asymptomatic; LIMAs, human left internal mammary arteries; Lp-PLA2, lipoprotein-associated phospholipase A2; LPS, lipopolysaccharide; and TSA, trichostatin A