DNA methylation of tumour necrosis factor (TNF) alpha gene is associated with specific blood fatty acid levels in a gender-specific manner.

ABSTRACT

BACKGROUND: Fatty acids, specifically polyunsaturated fatty acids (PUFAs) play an important role in inflammation and its resolution, however, their interaction with the epigenome is relatively unexplored. Here we investigate the relationship between circulating blood fatty acids and the DNA methylation of the cytokine encoding gene tumour necrosis factor (TNF, OMIM 191160). METHODS: Using a cross-sectional study approach, we collected blood samples from adults (N=88 (30 males, 58 females); 18-74 years old) for DNA methylation pyrosequencing analysis at four sites in TNF exon 1 and gas-chromatography mass-spectrometry analysis of the fatty acid profile of dried blood spots (DBS). RESULTS: Methylation levels of TNF exon 1 are significantly correlated with specific fatty acids in a gender-specific manner. In the males the PUFAs Docosahexaenoic Acid (DHA) and Arachidonic Acid (AA) were positively associated with TNF methylation, as was the saturated fatty acid (SFA) Stearic Acid; in contrast, mono-unsaturated fatty acids (MUFAs) had a negative association. In the females, omega-6 PUFA γ-Linolenic acid (GLA) was negatively correlated with TNF methylation; Adrenic acid and Eicosadienoic Acid were positively correlated with TNF methylation. CONCLUSION: These results suggest that one way that fatty acids interact with the inflammation is through altered methylation profiles of cytokine genes; thus, providing potential therapeutic targets for nutritional and health interventions.