Figure 3

NOS3 gene methylation levels vary according to genomic location in HPAEC and HPVEC cells. A. UCSC Genome Browser View of NOS3 showing chromosomal coordinates (Chr7 - chromosome 7), location of HM450 array probes, CpG sites (black vertical dashes), alternative splice variants including differential exons (blue bar) and introns (arrowed lines), CpG islands (green bar). B. Magnified view of regions of differential methylation of the NOS3 gene between HPAEC and HPVEC. C. Graphical summary of mean NOS3 methylation level (y-axis) in HPAEC (open triangles; n=9) relative to HPVEC (closed squares; n=9) for HM450 probes 1–14 in A. (x-axis) highlights a region of methylation of the major NOS3 promoter (i) and reciprocal hypomethylation of a downstream CpG island (iii) in HPVEC relative to HPAEC cells . Error bars denote 95% confidence interval and asterisks denote level of significance of array data according to adjusted p-value from linear regression analysis. D. DNA Methylation patterns detected by Sequenom EpiTYPER around the two regions corresponding to the HM450 probes. This cross-platform analysis further confirms the methylation of the major NOS3 promoter in HPVEC (i) and the reciprocal hypomethylation of the downstream CpG island (ii) Error bars – 95% confidence interval.