ABSTRACT
The circadian clock regulates the daily rhythms of several physiological and behavioral processes. Disruptions in clock genes have been associated with obesity and related comorbidities. This study aimed to analyze the association of DNA methylation signatures at circadian rhythm pathway genes with body mass index (BMI), metabolic profiles and dietary intakes. DNA methylation profiling was determined by microarray in white blood cells from 474 adults from the Methyl Epigenome Network Association (MENA) project. Kyoto Encyclopedia of Genes and Genomes database was used to identify the genes integrating the circadian rhythm pathway. Network enrichment analyses were performed with the PathDIP platform. Associations between circadian methylation patterns with anthropometric measurements, the metabolic profile, clinical data and dietary intakes were analyzed. DNA methylation patterns of nine CpG sites at six circadian rhythm pathway genes were strongly correlated with BMI (false discovery rates <0.0001). These CpGs encompassed cg09578018 (RORA), cg20406576 (PRKAG2), cg10059324 (PER3), cg01180628 (BHLHE40), cg23871860 (FBXL3), cg16964728 (RORA), cg14129040 (CREB1), cg07012178 (PRKAG2) and cg24061580 (PRKAG2). Interestingly, network enrichment analyses revealed that the six BMI-associated genes statistically contributed to the regulation of the circadian rhythm pathway (p = 1.9E-10). In addition, methylation signatures at cg09578018 (RORA), cg24061580 (PRKAG2), cg01180628 (BHLHE40) and cg10059324 (PER3) also correlated with insulin resistance (p < 0.0001) and mean arterial blood pressure (p < 0.0001). Furthermore, relevant correlations (p < 0.05) between methylation at cg09578018 (RORA) and cg01180628 (BHLHE40) with total energy and carbohydrate intakes were found. This investigation revealed potential associations of DNA methylation profiles at circadian genes with obesity, metabolic disturbances and carbohydrate intake, with potential impact on weight homeostasis.
Acknowledgements
The authors thank all the participants of this study, the personnel of the health centers and investigators of the different research groups for their participation in the recruitment process and data acquisition. Technical and laboratory support from Maria Hernandez, Salome Perez, Blanca Martinez de Morentin, Ana Lorente, Veronica Ciaurriz, Maria Zabala, Asuncion Redin, Laura Olazaran and Iosune Zubieta is especially acknowledged. The MENA Project is constituted by the cohorts PREDIMED, OBEPALIP, GEDYMET, DiOGenes, RESMENA, NUGENOB, Food4Me and ICTUS, where each of the following researchers in alphabetical order is involved: Alonso A, Arancibia C, Arós F, Astrup A, Babio N, Blázquez V, Bondia-Pons I, Brennan L, Buil-Cosiales P, Campión J, Cataldo LR, Celis-Morales C, Corella D, Covas MI, Dalskov S, Daniel H, De Arce A, de la Iglesia R, Estruch R, Fernández-Crehuet J, Fiol M, Fitó M, Flores M, Forga L, Galgani J, Gibney ER, Gibney MJ, Gómez-Úriz AM, González-Muniesa P, Goyenechea E, Guy-Grand B, Handjieva-Darlenska T, Holst C, Huerta AE, Jebb S, Kafatos A, Kunesová M, Lamuela-Raventós RM, Langin D, Lapetra J, Larsen TM, López De Munain A, López-Legarrea P, Lovegrove JA, Macdonald I, Manios Y, Martínez-Zabaleta MT, Mathers JC, Morales M, Muñoz MA, Olmos P, Pedersen O, Petersen M, Pfeiffer A, Pintó X, Pollak F, PREDIMED Investigators, Prieto-Hontoria PL, Ros E, Rössner S, Ruiz-Gutierrez V, Salas-Salvadó J, Saris WH, Serra-Majem L, Sørensen TI, Sorlí JV, Stich V, Taylor MA, Toledo E, Toubro S, Traczyk I, Valderas JP, van Baak M, Vega J, Verdich C, Walsh M and Yévenes I.
Declaration of Interest
The authors declare that there is no conflict of interest concerning this research.
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