RESUMO
The main aim of this investigation was to study the regulatory roles of let-7b and miR-155-3p on the expression of inflammation-associated genes in monocytes, macrophages, and lipopolysaccharide (LPS)-activated macrophages (AcM). A second goal was to analyze the potential modulatory roles of different fatty acids, including oleic, palmitic, eicosapentaenoic (EPA), and docosahexaenoic (DHA), on the expression of these miRNAs in the three cell types. This hypothesis was tested in human acute monocytic leukemia cells (THP-1), which were differentiated into macrophages with 2-O-tetradecanoylphorbol-13-acetate (TPA) and further activated with LPS for 24 h. Monocytes, macrophages, and AcM were transfected with a negative control, or mimics for miR-155-3p and miR-let-7b-5p. The expression of both miRNAs and some proinflammatory genes was analyzed by qRT-PCR. Interestingly, let-7b mimic reduced the expression of IL6 and TNF in monocytes, and SERPINE1 expression in LPS-activated macrophages. However, IL6, TNF, and SERPINE1 were upregulated in macrophages by let-7b mimic. IL6 expression was higher in the three types of cells after transfecting with miR-155-3p mimic. Similarly, expression of SERPINE1 was increased by miR-155-3p mimic in monocytes and macrophages. However, TLR4 was downregulated by miR-155-3p in monocytes and macrophages. Regarding the effects of the different fatty acids, oleic acid increased the expression of let-7b in macrophages and AcM and also increased the expression of miR-155 in monocytes when compared with DHA but not when compared with non-treated cells. Overall, these results suggest anti- and proinflammatory roles of let-7b and miR-155-3p in THP-1 cells, respectively, although these outcomes are strongly dependent on the cell type. Noteworthy, oleic acid might exert beneficial anti-inflammatory effects in immune cells (i.e., non-activated and LPS-activated macrophages) by upregulating the expression of let-7b.
Assuntos
Ácidos Graxos não Esterificados/metabolismo , Regulação da Expressão Gênica , Macrófagos/metabolismo , MicroRNAs/metabolismo , Monócitos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-6/agonistas , Interleucina-6/antagonistas & inibidores , Interleucina-6/genética , Interleucina-6/metabolismo , Lipopolissacarídeos/toxicidade , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , MicroRNAs/química , Monócitos/imunologia , Ácido Oleico/metabolismo , Inibidor 1 de Ativador de Plasminogênio/agonistas , Inibidor 1 de Ativador de Plasminogênio/química , Inibidor 1 de Ativador de Plasminogênio/genética , Inibidor 1 de Ativador de Plasminogênio/metabolismo , RNA/metabolismo , Células THP-1 , Acetato de Tetradecanoilforbol/farmacologia , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/agonistas , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
BACKGROUND: Epigenetic mechanisms may be involved in obesity onset and its consequences. The aim of the present study was to evaluate whether DNA methylation status in microRNA (miRNA) coding regions is associated with childhood obesity. MATERIAL AND METHODS: DNA isolated from white blood cells of 24 children (identification sample: 12 obese and 12 non-obese) from the Grupo Navarro de Obesidad Infantil study was hybridized in a 450 K methylation microarray. Several CpGs whose DNA methylation levels were statistically different between obese and non-obese were validated by MassArray® in 95 children (validation sample) from the same study. RESULTS: Microarray analysis identified 16 differentially methylated CpGs between both groups (6 hypermethylated and 10 hypomethylated). DNA methylation levels in miR-1203, miR-412 and miR-216A coding regions significantly correlated with body mass index standard deviation score (BMI-SDS) and explained up to 40% of the variation of BMI-SDS. The network analysis identified 19 well-defined obesity-relevant biological pathways from the KEGG database. MassArray® validation identified three regions located in or near miR-1203, miR-412 and miR-216A coding regions differentially methylated between obese and non-obese children. CONCLUSIONS: The current work identified three CpG sites located in coding regions of three miRNAs (miR-1203, miR-412 and miR-216A) that were differentially methylated between obese and non-obese children, suggesting a role of miRNA epigenetic regulation in childhood obesity.
Assuntos
Metilação de DNA , Obesidade Infantil/genética , Criança , Epigênese Genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , MicroRNAs/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodosRESUMO
The aim of this study is to compare the effect of conventional bread and a whole grain bread on appetite and energy intake, satiety and satiety gut-hormones. A randomized controlled crossover pilot study was carried out in 11 university students (age: 18.7 ± 0.9 years; body mass index: 22.7 ± 2.7 kg/m(2)). Participants consumed two different mid-morning cereal-based snacks, including a conventional or whole grain bread. Two testing days were completed, including satiety questionnaires, blood sampling and consumption of standardized breakfast, mid-morning test-snacks and ad libitum lunch. Several gut-hormones were analysed and satiation was assessed using Visual Analogue Scale scores. The consumption of whole grain bread increased satiety perception, decreased the remained energy intake during the testing day, and decreased the postprandial response of peptide YY, compared with conventional bread (p < 0.005). These data suggest that the consumption of whole grain bread might be a useful strategy to improve satiety.