Associations of B‐Type Natriuretic Peptide and Its Coding Gene Promoter Methylation With Functional Outcome of Acute Ischemic Stroke: A Mediation Analysis

Figures

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  Figure 1. Flowchart of selection of study participants. BNP indicates B‐type natriuretic peptide; CATIS, China Antihypertensive Trial in Acute Ischemic Stroke; and NPPB, natriuretic peptide B.

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  Figure 2. Schematic illustration of the targeted sequence and primers for targeted bisulfite sequencing. Red represents the CpG loci assayed in the NPPB gene promoter (−198 to +39 bp from TSS). NPPB indicates natriuretic peptide B; and TSS, transcriptional start site

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  Figure 3. Heat map illustrating the average methylation levels at all CpG loci in the NPPB promoter according to mRS score at 14 days or hospital discharge. Color depth shows the value of the corresponding methylation level. BNP, B‐type natriuretic peptide; mRS indicates the modified Rankin Scale; and NPPB, natriuretic peptide B.

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  Figure 4. Spearman correlation matrix of DNA methylation of all CpG loci assayed in the NPPB promoter and proBNP (after log10‐transformation) at admission. The areas of circles and color depth show the absolute value of corresponding correlation coefficients. BNP indicates B‐type natriuretic peptide; and NPPB, natriuretic peptide B.

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  Figure 5. Schematic illustration of the mediating effect of proBNP on the association between DNA methylation at CpG11 (located in Chr:11918989) in the NPPB promoter and the functional outcome at 14 days or hospital discharge in 704 patients with ischemic stroke. In this model, DNA methylation at CpG11 (per 5% increment) was the exposure variable, proBNP (after log10‐transformation) was the mediator variable, and mRS was the outcome variable, adjusting for age, sex, stroke subtype, National Institutes of Health Stroke Scale score, hours from onset to hospitalization, current smoking, current drinking, body mass index, systolic blood pressure, disease history (hypertension, diabetes mellitus, dyslipidemia, coronary heart disease), and treatment group at admission. * P<0.05. BNP indicates B‐type natriuretic peptide; mRS, the modified Rankin Scale; and NPPB, natriuretic peptide B.

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  Figure 6. Schematic illustration of the gene network and biological functions involving the NPPB gene. ANKRD1 indicates ankyrin repeat domain 1; ATXN1, Ataxin 1; CDX4, Caudal type homeobox 4; CORIN, corin; DIRAS1, DIRAS family GTPase 1; FNDC4, Fibronectin type III domain containing 4; HAGHL, Hydroxyacylglutathione hydrolase like; KCTD7, Potassium channel tetramerization domain containing 7; MYL7, myosin light chain 7; NPR1, natriuretic peptide receptor 1; NPR2, natriuretic peptide receptor 2; NPR3, natriuretic peptide receptor 3; NPPA, natriuretic peptide A; NPPB, natriuretic peptide B; NPPC, natriuretic peptide C; PLN, phospholamban; PRRG3, proline rich and Gla domain 3; RASAL1, RAS protein activator like 1; TAC1, Tachykinin precursor 1; TNNI1, troponin I1; and TNNT2, troponin T2.