Role of Dietary Factors on DNA Methylation Levels of TNF-Alpha Gene and Proteome Profiles in Obese Men

Abstract

Integrated omics-based platforms from epigenomics and proteomics technologies are used to identify several important mechanisms in obesity etiology, food components, dietary intake, regulation of biological pathways, and potential new intervention targets. Therefore, this study aimed to analyze whether dietary factors involved in the methylation of tumor necrosis factor (TNF)-α are implicated in differential protein expression in people with normal weight and obesity. Methods: The participants were classified into the non-obese (N = 100) and obese (N = 133) groups. DNA methylation levels of the TNF-alpha gene and proteomics were analyzed using the pyrosequencing method and LC-MS-MS, respectively. Results: Comparison between geometric means of DNA methylation of TNF-α showed lower levels in subjects with obesity than in those without obesity (p < 0.05). There were associations between dietary factors and some metabolic syndrome components and TNF-α DNA methylation levels. Proteomic analysis showed important signaling pathways related to obesity, with 95 significantly downregulated proteins and 181 upregulated proteins in the non-obese group compared with the obese group. Conclusion: This study shows an association between the dietary factors involved in the methylation of TNF-α and differential protein expression related to obesity. However, a large sample size in future studies is required to confirm our results.

Keywords

• TNF-α
• DNA methylation
• serum proteome
• signaling pathway