title: Hoxa5 undergoes dynamic DNA methylation and transcriptional repression in the adipose tissue of mice exposed to high-fat diet.
abstract: The genomic bases of the adipose tissue abnormalities induced by chronic positive calorie excess have been only partially elucidated. We adopted a genome-wide approach to directly test whether long-term high-fat diet (HFD) exposure affects the DNA methylation profile of the mouse adipose tissue and to identify the functional consequences of these changes.
  
  
  
  We have used epididymal fat of mice fed either high-fat (HFD) or regular chow (STD) diet for 5 months and performed genome-wide DNA methylation analyses by methylated DNA immunoprecipitation sequencing (MeDIP-seq). Mouse Homeobox (Hox) Gene DNA Methylation PCR, RT-qPCR and bisulphite sequencing analyses were then performed.
  
  
  
  Mice fed the HFD progressively expanded their adipose mass accompanied by a significant decrease in glucose tolerance (P<0.001) and insulin sensitivity (P<0.05). MeDIP-seq data analysis revealed a uniform distribution of differentially methylated regions (DMR) through the entire adipocyte genome, with a higher number of hypermethylated regions in HFD mice (P<0.005). This different methylation profile was accompanied by increased expression of the Dnmt3a DNA methyltransferase (Dnmt; P<0.05) and the methyl-CpG-binding domain protein Mbd3 (P<0.05) genes in HFD mice. Gene ontology analysis revealed that, in the HFD-treated mice, the Hox family of development genes was highly enriched in differentially methylated genes (P=0.008). To validate this finding, Hoxa5, which is implicated in fat tissue differentiation and remodeling, has been selected and analyzed by bisulphite sequencing, confirming hypermethylation in the adipose tissue from the HFD mice. Hoxa5 hypermethylation was associated with downregulation of Hoxa5 mRNA and protein expression. Feeding animals previously exposed to the HFD with a standard chow diet for two further months improved the metabolic phenotype of the animals, accompanied by return of Hoxa5 methylation and expression levels (P<0.05) to values similar to those of the control mice maintained under standard chow.
  
  
  
  HFD induces adipose tissue abnormalities accompanied by epigenetic changes at the Hoxa5 adipose tissue remodeling gene.
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Parrillo
authors.affiliation: Institute of Genetics and Biophysics 'Adriano Buzzati-Traverso', National Research Council, Naples, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Costa
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: G A
authors.initials: GA
authors.lastname: Raciti
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Longo
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Spinelli
authors.affiliation: Institute of Genetics and Biophysics 'Adriano Buzzati-Traverso', National Research Council, Naples, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Esposito
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Nigro
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Vastolo
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Desiderio
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Zatterale
authors.affiliation: Institute of Genetics and Biophysics 'Adriano Buzzati-Traverso', National Research Council, Naples, Italy.|DiST, Department of Science and Technology, 'Parthenope' University of Naples, Centro Direzionale, Naples, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Ciccodicola
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Formisano
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Miele
authors.affiliation: Dipartimento di Scienze Mediche e Traslazionali dell'Università di Napoli 'Federico II', Naples, Italy.|URT dell'Istituto di Endocrinologia e Oncologia Sperimentale 'Gaetano Salvatore', Consiglio Nazionale delle Ricerche, Naples, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Beguinot
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D019175:DNA Methylation; D059305:Diet, High-Fat; D004195:Disease Models, Animal; D015536:Down-Regulation; D044127:Epigenesis, Genetic; D018398:Homeodomain Proteins / Q000235:genetics*; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000235:genetics; D010750:Phosphoproteins / Q000235:genetics*; D014157:Transcription Factors; D014158:Transcription, Genetic
chemical_list: D018398:Homeodomain Proteins; C059637:Hoxa5 protein, mouse; D010750:Phosphoproteins; D014157:Transcription Factors