1 2008 Vol: 33(11):2605-2609. DOI: 10.1038/sj.npp.1301662

Epigenetic Downregulation of Atrial Natriuretic Peptide but not Vasopressin mRNA Expression in Females with Eating Disorders is Related to Impulsivity

Disturbances of volume-regulating mechanisms have already been implicated in the pathophysiology of eating disorders like anorexia or bulimia nervosa with the peptide hormones vasopressin and atrial natriuretic peptide (ANP) being of special interest. Aim of the present study was to investigate, whether the expression of the corresponding genes was altered and if so, if these changes could be explained by epigenetic mechanisms such as DNA methylation. We analyzed blood samples of 46 women suffering from anorexia (n=22) or bulimia nervosa (n=24) as well as of 30 healthy controls. Peripheral mRNA expression and DNA methylation of the vasopressin and the ANP precursor genes were assessed using real-time PCR. We found significantly lower levels of ANP mRNA in patients with eating disorders. This downregulation was accompanied by a hypermethylation of the ANP gene promoter in the bulimic subgroup. We did not find differences regarding expression or methylation of the vasopressin gene. ANP mRNA expression was inversely associated with impaired impulse regulation. We conclude that epigenetic mechanisms may contribute to the known alterations of ANP homeostasis in women with eating disorders.

Mentions
Figures
Figure 1: RNA expression and DNA methylation of the atrial natriuretic precursor peptide gene. Women suffering from anorexia (AN) or bulimia nervosa (BN) have a significantly lower mRNA expression in the blood than healthy women (a). This downregulation is partially mediated by epigenetic DNA hypermethylation of the corresponding gene's promoter structure (b). P-values indicated in the figure are derived from Bonferroni's post hoc test after one-way analysis of variance (ANOVA). Further statistical details are summarized in the 'Results' and 'Materials and Methods' sections. Figure 2: Scatter plot of the relation between atrial natriuretic precursor peptide gene's expression and scores of the eating disorder inventory 2 (EDI-2). The figures show the relation between the mRNA expression of atrial natriuretic peptide (ANP) and the sum score (a) or the impulse regulation (IR) disturbance score (b) of the EDI-2. The straight line represents the regression curve of a simple linear regression with it's 95% confidence interval (dashed lines).
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References
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