DNA methylation of the natriuretic peptides system genes and ischemic stroke: gene-based and gene-set analyses

<p><span><b>Background</b></span></p> <p><span>The natriuretic peptides (NP) system has been considered an important regulator for ischemic stroke (IS) with a limited clinical implication. A better understanding of the underlying molecular mechanisms is urgent. Here, we aimed to examine the role of NP system genes methylation in IS.</span></p> <p><span><b>Methods and Results</b></span></p> <p><span>DNA methylation at promoter regions of four core NP system genes, e.g., <i>CORIN</i>, <i>FURIN</i>, <i>NPPA</i>, and <i>NPPB</i>, was measured by targeted bisulfite sequencing in 853 IS patients and 918 healthy controls. We first examined the association between DNA methylation at each single CpG and IS, followed by gene-based and gene-set analyses to examine the joint associations of DNA methylation at multiple CpGs in a gene or all four genes as a pathway with IS. After control of covariates and multiple testing, DNA methylation at 19 of the 36 assayed CpGs were individually associated with IS at q&lt;0.05. The average methylation levels at the targeted regions of <i>CORIN</i> (OR=0.64, 95%CI: 0.56-0.73), <i>FURIN</i> (OR=0.78, 95%CI: 0.69-0.88), and <i>NPPA</i> (OR=0.78, 95%CI: 0.69-0.88) were inversely associated with IS (all q&lt;0.05). The truncated product method revealed the same gene-based associations (all q&lt;0.05) and found that DNA methylation at all four NP system genes together was jointly associated with IS (<i>P</i>=0.0001).</span></p> <p><span><b>Conclusions</b></span></p> <p><span>DNA methylation at NP system genes was downregulated in IS patients. Our results may unravel a molecular mechanism underlying the regulating effect of the NP system on IS, and highlight the relevance of testing the joint effect of multiple CpGs in the epigenetic analysis.</span></p>