Fig. 4

DNA methylation of CpG locus at AVPR1a gene promoter in human umbilical vein. a Bioinformatic analysis of CpG islands of AVPR1a gene from upstream − 1.5 kb to downstream + 1.5 kb region. Sequence analysis identified one CpG island in exon that contains 14 CpG sites, located at positions + 1292 to + 1484 from the translation start site (TSS, defined as position 1) in AVPR1a gene promoter. b The mRNA levels of AVPR1a in HUVECs after treatment with 5-Aza-2′-deoxycytidine (5-Aza) for 2 days. c Represent image of bisulfite conversion efficiency between NP and PE group (N = 30 each group). d–e The mean methylation status of CpG locus (the total and each tested) at AVPR1a gene promoter in HUV (N = 30 each group). f Expression analysis of AVPR1a gene and its correlation with methylation levels of CpG sites (5 and 6). DNA methylation/mRNA correlation plots for AVPR1a gene identified by causal inference test (N = 30 each group). The Y-axis represents the relative expression level of AVPR1a gene which was detected with qRT-PCR method. The X-axis represents the relative mean methylation level of the CpG sites (5 and 6) at AVPR1a gene promoter in HUV. r: Pearson correlation coefficient. g mRNA levels of AVPR1a gene in normal and pre-eclamptic HUVECs after 5-Aza treatment (N = 8 each group). Error bars denote SEM. *P < 0.05; **P < 0.01; ***P < 0.001. N number of participants