RESUMO
Ischemic stroke patients often show high concentrations of circulating inflammatory markers that are associated with increased risk of recurrence. Epigenetic mechanisms could be involved in obesity, inflammation and stroke. The objective of this research was to investigate, in obese patients suffering a previous stroke, the effects of a nutritional program on anthropometric and biochemical variables, and on the methylation patterns of two stroke-related genes (KCNQ1: potassium channel, voltage gated KQT-like subfamily Q, member 1; and WT1: Wilms tumor 1). Twenty-two ischemic stroke patients were compared with a control group composed of eighteen obese subjects with similar age and body mass index ranges. Both groups followed a 20-week nutritional program based on an energy-restricted balanced diet with high adherence to the Mediterranean dietary pattern. The intervention significantly improved anthropometric and metabolic variables, such as the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and C-reactive protein concentration, in ischemic stroke patients, and was accompanied by changes in the methylation patterns of both stroke-related genes, which correlated with anthropometric and biochemical variables.
Assuntos
Metilação de DNA/genética , Dieta Redutora/métodos , Canal de Potássio KCNQ1/genética , Obesidade , Acidente Vascular Cerebral , Proteínas WT1/genética , Idoso , Antropometria , Glicemia , Pressão Sanguínea , Composição Corporal , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Epigênese Genética , Feminino , Humanos , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/dietoterapia , Obesidade/genética , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/genéticaRESUMO
Obesity and stroke are multifactorial diseases in which genetic, epigenetic and lifestyle factors are involved. The research aims were, first, the description of genes with differential epigenetic regulation obtained by an 'omics' approach in patients with ischemic stroke and, second, to determine the importance of some regions of these selected genes in biological processes depending on the body mass index. A case-control study using two populations was designed. The first population consisted of 24 volunteers according to stroke/non-stroke and normal weight/obesity conditions. The second population included 60 stroke patients and 55 controls classified by adiposity. DNA from the first population was analyzed with a methylation microarray, showing 80 cytosine-guanine dinucleotides (CpG) sites differentially methylated in stroke and 96 CpGs in obesity, whereas 59 CpGs showed interaction. After validating these data by MassArray Epityper, the promoter region of peptidase M20 domain containing 1 (PM20D1) gene was significantly hypermethylated in stroke patients. One CpG site at Caldesmon 1 (CALD1) gene showed an interaction between stroke and obesity. Two CpGs located in the genes Wilms' tumor 1 (WT1) and potassium voltage-gated channel, KQT-like subfamily, member 1 (KCNQ1) were significantly hypermethylated in obese patients. In the second population, KCNQ1 was also hypermethylated in the obese subjects. Two CpGs of this gene were subsequently validated by methylation-sensitive high-resolution melting. Moreover, KCNQ1 methylation levels were associated with plasma KCNQ1 protein concentrations. In conclusion, obesity induced changes in the KCNQ1 methylation pattern which were also dependent on stroke. Furthermore, the epigenetic marks differentially methylated in the stroke patients were dependent on the previous obese state. These DNA methylation patterns could be used as future potential stroke biomarkers.
Assuntos
Metilação de DNA , Canal de Potássio KCNQ1/genética , Leucócitos/metabolismo , Obesidade/genética , Acidente Vascular Cerebral/genética , Idoso , Índice de Massa Corporal , Calmodulina/genética , Calmodulina/metabolismo , Proteínas de Ligação a Calmodulina/genética , Proteínas de Ligação a Calmodulina/metabolismo , Estudos de Casos e Controles , Ilhas de CpG , Epigênese Genética , Feminino , Marcadores Genéticos , Humanos , Canal de Potássio KCNQ1/sangue , Modelos Lineares , Masculino , Metaloproteases/genética , Metaloproteases/metabolismo , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Proteínas WT1/genética , Proteínas WT1/metabolismoRESUMO
Epigenetics could help to explain individual differences in weight loss after an energy-restriction intervention. Here, we identify novel potential epigenetic biomarkers of weight loss, comparing DNA methylation patterns of high and low responders to a hypocaloric diet. Twenty-five overweight or obese men participated in an 8-wk caloric restriction intervention. DNA was isolated from peripheral blood mononuclear cells and treated with bisulfite. The basal and endpoint epigenetic differences between high and low responders were analyzed by methylation microarray, which was also useful in comparing epigenetic changes due to the nutrition intervention. Subsequently, MALDI-TOF mass spectrometry was used to validate several relevant CpGs and the surrounding regions. DNA methylation levels in several CpGs located in the ATP10A and CD44 genes showed statistical baseline differences depending on the weight-loss outcome. At the treatment endpoint, DNA methylation levels of several CpGs on the WT1 promoter were statistically more methylated in the high than in the low responders. Finally, different CpG sites from WT1 and ATP10A were significantly modified as a result of the intervention. In summary, hypocaloric-diet-induced weight loss in humans could alter DNA methylation status of specific genes. Moreover, baseline DNA methylation patterns may be used as epigenetic markers that could help to predict weight loss.