DNA methylation pattern changes following a short-term hypocaloric diet in women with obesity.

BACKGROUND/OBJECTIVES: We aimed to investigate the effects of short-term hypocaloric diet-induced weight loss on DNA methylation profile in leukocytes from women with severe obesity. METHODS: Eleven women with morbid obesity (age: 36.9 ± 10.3 years; BMI: 58.5 ± 10.5 kg/m2) were assessed before and after 6 weeks of a hypocaloric dietary intervention. The participants were compared with women of average weight and the same age (age: 36.9 ± 11.8 years; BMI: 22.5 ± 1.6 kg/m2). Genome-wide DNA methylation analysis was performed in DNA extracted from peripheral blood leukocytes using the Infinium Human Methylation 450 BeadChip assay. Changes (Δß) in the methylation level of each CpGs were calculated. A threshold with a minimum value of 10%, p < 0.001, for the significant CpG sites based on Δß and a false discovery rate of <0.05 was set. RESULTS: Dietary intervention changed the methylation levels at 16,064 CpG sites. These CpGs sites were related to cancer, cell cycle-related, MAPK, Rap1, and Ras signaling pathways. However, regardless of hypocaloric intervention, a group of 878 CpGs (related to 649 genes) remained significantly altered in obese women when compared with normal-weight women. Pathway enrichment analysis identified genes related to the cadherin and Wnt pathway, angiogenesis signaling, and p53 pathways by glucose deprivation. CONCLUSION: A short-term hypocaloric intervention in patients with severe obesity partially restored the obesity-related DNA methylation pattern. Thus, the full change of obesity-related DNA methylation patterns could be proportional to the weight-loss rate in these patients after dietary interventions.

Altered pathways in methylome and transcriptome longitudinal analysis of normal weight and bariatric surgery women.

DNA methylation could provide a link between environmental, genetic factors and weight control and can modify gene expression pattern. This study aimed to identify genes, which are differentially expressed and methylated depending on adiposity state by evaluating normal weight women and obese women before and after bariatric surgery (BS). We enrolled 24 normal weight (BMI: 22.5 ± 1.6 kg/m2) and 24 obese women (BMI: 43.3 ± 5.7 kg/m2) submitted to BS. Genome-wide methylation analysis was conducted using Infinium Human Methylation 450 BeadChip (threshold for significant CpG sites based on delta methylation level with a minimum value of 5%, a false discovery rate correction (FDR) of q < 0.05 was applied). Expression levels were measured using HumanHT-12v4 Expression BeadChip (cutoff of p ≤ 0.05 and fold change ≥2.0 was used to detect differentially expressed probes). The integrative analysis of both array data identified four genes (i.e. TPP2, PSMG6, ARL6IP1 and FAM49B) with higher methylation and lower expression level in pre-surgery women compared to normal weight women: and two genes (i.e. ZFP36L1 and USP32) that were differentially methylated after BS. These methylation changes were in promoter region and gene body. All genes are related to MAPK cascade, NIK/NF-kappaB signaling, cellular response to insulin stimulus, proteolysis and others. Integrating analysis of DNA methylation and gene expression evidenced that there is a set of genes relevant to obesity that changed after BS. A gene ontology analysis showed that these genes were enriched in biological functions related to adipogenesis, orexigenic, oxidative stress and insulin metabolism pathways. Also, our results suggest that although methylation plays a role in gene silencing, the majority of effects were not correlated.

Lipid peroxidation and antioxidant capacity of G6PD-deficient patients with A-(202G>A) mutation.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an enzymopathy in which reduced NADPH concentrations are not maintained, resulting in oxidative damage. We evaluated G6PD activity, oxidative stress levels and Trolox equivalent antioxidant capacity in individuals with the A-(202G>A) mutation for G6PD deficiency. Five hundred and forty-four peripheral blood samples were screened for G6PD deficiency; we also analyzed lipid peroxidation products measured as thiobarbituric acid reactive species and Trolox equivalent antioxidant capacity. Men with the A-(202G>A) mutation had lower G6PD activity than women with the same mutation. Individuals with the A-(202G>A) mutation also differed in mean Trolox equivalent antioxidant capacity values but not for thiobarbituric acid reactive species values. We concluded that A-(202G>A) mutation is associated with reduced G6PD activity and increased Trolox equivalent antioxidant capacity.

DNA methylation screening after roux-en Y gastric bypass reveals the epigenetic signature stems from genes related to the surgery per se.

BACKGROUND/OBJECTIVES: Obesity has been associated with gene methylation regulation. Recent studies have shown that epigenetic signature plays a role in metabolic homeostasis after Roux-en Y gastric bypass (RYGB). To conduct a genome-wide epigenetic analysis in peripheral blood to investigate whether epigenetic changes following RYGB stem from weight loss or the surgical procedure per se. SUBJECTS/METHODS: By means of the Infinium Human Methylation 450 BeadChip array, global methylation was analyzed in blood of 24 severely obese women before and 6 months after RYGB and in 24 normal-weight women (controls). RESULTS: In blood cells, nine DMCpG sites showed low methylation levels before surgery, methylation levels increased after RYGB and neared the levels measured in the controls. Additionally, 44 CpG sites associated with the Wnt and p53 signaling pathways were always differently methylated in the severely obese patients as compared to the controls and were not influenced by RYGB. Finally, 1638 CpG sites related to inflammation, angiogenesis, and apoptosis presented distinct methylation in the post-surgery patients as compared to the controls. CONCLUSION: Bariatric surgery per se acts on CpGs related to inflammation, angiogenesis, and endothelin-signaling. However, the gene cluster associated with obesity remains unchanged, suggesting that weight loss 6 months after RYGB surgery cannot promote this effect.

Edible mushroom Agaricus sylvaticus can prevent the onset of atheroma plaques in hipercholesterolemic rabbits.

Since the involvement of free radicals in the pathophysiology of atherosclerosis was proposed, antioxidant supplementation arose as a potential strategy for the management of this disease. Thus, we decided to investigate the potential benefit of a natural antioxidant--rich edible mushroom (Agaricus sylvaticus) on the prevention of atherosclerosis. New Zealand rabbits underwent atherosclerosis induction by feeding a cholesterol--enriched chow (Group A), while Group B simultaneously received edible mushroom A. sylvaticus water solution. Control group received standard rabbit chow only (Group C). At the end of 10 week treatment period serum samples were drawn for lipid profile, uric acid, thiobarbituric acid reactive substances (TBARS), and total antioxidant status (TAS). The area of aorta arteries taken by atheroma plaques was evaluated. Groups A and B presented higher cholesterol levels (p< 0.01) and reduced TAS (p<0.01), when compared to the Group C. However, TBARS and uric acid levels for Group B animals' were reduced, in comparison to Group A (p<0.05), and equals to group C. Moreover, animals from group A developed extensive atherosclerotic areas (47.0+/-14.0%), and that was prevented by the supplementation of A. sylvaticus (6.6+/-2.9%, p<0.01). Data suggested that A. sylvaticus can prevent the development of atherosclerosis in spite of hipercholesterolemia.

Relevance of apolipoprotein E4 for the lipid profile of Brazilian patients with coronary artery disease.

Apolipoprotein E (apoE - e2, e3, e4 alleles) plays a role in the regulation of lipid metabolism, with the e4 considered to be a risk factor for coronary artery disease (CAD). We aimed to evaluate the apoE polymorphisms in Brazilians with CAD and their influence on the lipid profile and other risk factors (hypertension, diabetes mellitus, smoking). Two hundred individuals were examined: 100 patients with atherosclerosis confirmed by coronary angiography and 100 controls. Blood samples were drawn to determine apoE polymorphisms and lipid profile. As expected, the e3 allele was prevalent in the CAD (0.87) and non-CAD groups (0.81; P = 0.099), followed by the e4 allele (0.09 and 0.14, respectively; P = 0.158). The e3/3 (76 and 78%) and e3/4 (16 and 23%) were the most common genotypes for patients and controls, respectively. The lipid profile was altered in patients compared to controls (P < 0.05), independently of the e4 allele. However, in the controls this allele was prevalent in individuals with elevated LDL-cholesterol levels only (odds ratio = 2.531; 95% CI = 1.028-6.232). The frequency of risk factors was higher in the CAD group (P < 0.05), but their association with the lipid profile was not demonstrable in e4 carriers. In conclusion, the e4 allele is not associated with CAD or lipid profile in patients with atherosclerosis. However, its frequency in the non-CAD group is associated with increased levels of LDL-cholesterol, suggesting an independent effect of the e4 allele on lipid profile when the low frequency of other risk factors in this group is taken into account.

Role of UCP2 polymorphisms on dietary intake of obese patients who underwent bariatric surgery.

Uncoupling protein 2 ( UCP2 ) plays an important role in body weight and energy metabolism and may be related to the control of food consumption. This study aimed to investigate the contribution of UCP2 gene variants on the dietary intake on a population after bariatric surgery. This study enrolled 150 obese patients (body mass index ≥ 35kg m(-2) ) who submitted to Roux-en-Y gastric bypass. Weight (kg), BMI (kg m(-2) ), energy (kcal d(-1) ) and macronutrients intake (g d(-1) ) of preoperative and 1-year postoperative period were collected from medical records. Ala55Val and -866G>A polymorphisms in the UCP2 gene were genotyped through allelic discrimination method in real-time polymerase chain reaction using the TaqMan pre-designed SNP Genotyping Assays kits. Hardy-Weinberg equilibrium, t-test and regression models were performed in statistical analysis (P<0.05).We found an allelic frequency of 0.44 for allele Val and 0.41 for allele A. In the postoperative period, patients with at least one rare allele for polymorphisms and with at least one rare allele for both polymorphisms together (haplotype) present a greater energy and carbohydrate intake, even after adjusting for gender, age and weight. Genetic variants in UCP2 gene were associated with the dietary consumption after Roux-En-Y gastric bypass.

Association between apolipoprotein E genotype, serum lipids, and colorectal cancer in Brazilian individuals.

We evaluated genetic variants of apolipoprotein E (APOE HhaI) and their association with serum lipids in colorectal cancer (CRC), together with eating habits and personal history. Eight-seven adults with CRC and 73 controls were studied. APOE*2 (rs7412) and APOE*4 (rs429358) were identified by polymerase chain reaction-restriction fragment length polymorphism. APOE gene polymorphisms were similar in both groups, but the epsilon4/epsilon4 genotype (6%) was present only in controls. The patients had reduced levels (mean +/- SD) of total cholesterol and low-density lipoprotein cholesterol fraction (180.4 +/- 49.5 and 116.1 +/- 43.1 mg/dL, respectively) compared to controls (204.2 +/- 55.6, P = 0.135 and 134.7 +/- 50.8 mg/dL; P = 0.330, respectively) indicating that they were not statistically significant after the Bonferroni correction. The APOE*4 allele was associated with lower levels of total cholesterol, low- and high-density lipoprotein cholesterol fraction and increased levels of very low-density lipoprotein cholesterol fraction and triglycerides only among patients (P = 0.014). There was a positive correlation between the altered lipid profile and increased body mass indexes in both groups (P < 0.010). Moreover, a higher rate of hypertension and overweight was observed in controls (P < 0.002). In conclusion, the presence of the epsilon4/epsilon4 genotype only in controls may be due to a protective effect against CRC. Lower lipid profile values among patients, even those on lipid-rich diets associated with the APOE*4 allele, suggest alterations in the lipid synthesis and metabolism pathways in CRC.

Association between apolipoprotein E genotype, serum lipids, and colorectal cancer in Brazilian individuals

We evaluated genetic variants of apolipoprotein E (APOE HhaI) and their association with serum lipids in colorectal cancer (CRC), together with eating habits and personal history. Eight-seven adults with CRC and 73 controls were studied. APOE*2 (rs7412) and APOE*4 (rs429358) were identified by polymerase chain reaction-restriction fragment length polymorphism. APOE gene polymorphisms were similar in both groups, but the å4/å4 genotype (6 percent) was present only in controls. The patients had reduced levels (mean ± SD) of total cholesterol and low-density lipoprotein cholesterol fraction (180.4 ± 49.5 and 116.1 ± 43.1 mg/dL, respectively) compared to controls (204.2 ± 55.6, P = 0.135 and 134.7 ± 50.8 mg/dL; P = 0.330, respectively) indicating that they were not statistically significant after the Bonferroni correction. The APOE*4 allele was associated with lower levels of total cholesterol, low- and high-density lipoprotein cholesterol fraction and increased levels of very low-density lipoprotein cholesterol fraction and triglycerides only among patients (P = 0.014). There was a positive correlation between the altered lipid profile and increased body mass indexes in both groups (P < 0.010). Moreover, a higher rate of hypertension and overweight was observed in controls (P < 0.002). In conclusion, the presence of the å4/å4 genotype only in controls may be due to a protective effect against CRC. Lower lipid profile values among patients, even those on lipid-rich diets associated with the APOE*4 allele, suggest alterations in the lipid synthesis and metabolism pathways in CRC.

Relevance of apolipoprotein E4 for the lipid profile of Brazilian patients with coronary artery disease

Apolipoprotein E (apoE - e2, e3, e4 alleles) plays a role in the regulation of lipid metabolism, with the e4 considered to be a risk factor for coronary artery disease (CAD). We aimed to evaluate the apoE polymorphisms in Brazilians with CAD and their influence on the lipid profile and other risk factors (hypertension, diabetes mellitus, smoking). Two hundred individuals were examined: 100 patients with atherosclerosis confirmed by coronary angiography and 100 controls. Blood samples were drawn to determine apoE polymorphisms and lipid profile. As expected, the e3 allele was prevalent in the CAD (0.87) and non-CAD groups (0.81; P = 0.099), followed by the e4 allele (0.09 and 0.14, respectively; P = 0.158). The e3/3 (76 and 78 percent) and e3/4 (16 and 23 percent) were the most common genotypes for patients and controls, respectively. The lipid profile was altered in patients compared to controls (P < 0.05), independently of the e4 allele. However, in the controls this allele was prevalent in individuals with elevated LDL-cholesterol levels only (odds ratio = 2.531; 95 percent CI = 1.028-6.232). The frequency of risk factors was higher in the CAD group (P < 0.05), but their association with the lipid profile was not demonstrable in e4 carriers. In conclusion, the e4 allele is not associated with CAD or lipid profile in patients with atherosclerosis. However, its frequency in the non-CAD group is associated with increased levels of LDL-cholesterol, suggesting an independent effect of the e4 allele on lipid profile when the low frequency of other risk factors in this group is taken into account.