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

[Abstract] 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.This study’s data collection, DNA and statistical analysis was supported by São Paulo Research Foundation (FAPESP) (grants #2017/07220–7, #2016/05638–1 and #2015/18669–0). Also, statistical and bioinformatics analysis was supported by “Centro de Investigacion Biomedica En Red” (CIBERobn) and grants (PI17/01287) from the “Instituto de Salud Carlos III” (ISCIII), Spain, co-financed by the European Regional Development Fund (FEDER), MINECO grants MTM2014–52876-R and MTM2017–82724-R, and by the Xunta de Galicia (Grupos de Referencia Competitiva ED431C-2016-015 and Centro Singular de Investigación de Galicia ED431G/01), all of them through the ERDF. A Diaz-Lagares is funded by a research contract “Juan Rodés” (JR17/00016) and Ana B Crujeiras is funded by a research contract “Miguel Servet” (CP17/00088) from the ISCIII, co-financed by the European Regional Development Fund (FEDER)Brasil. Fundação de Amparo à Pesquisa do Estado de São Paulo; #2017/07220–7Brasil. Fundação de Amparo à Pesquisa do Estado de São Paulo; #2016/05638–1Brasil. Fundação de Amparo à Pesquisa do Estado de São Paulo; #2015/18669–0Xunta de Galicia; ED431C-2016-015Xunta de Galicia; ED431G/0

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

[Abstract] 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.São Paulo Research Foundation; 2017/07220-7São Paulo Research Foundation; #2016/05638-1São Paulo Research Foundation; #2013/12819-4São Paulo Research Foundation; #2015/18669-0Instituto de Salud Carlos III; PI17/01287Ministerio de Economía y Empresa; MTM2014-52876-RMinisterio de Economía y Empresa; MTM2017-82724-RXunta de Galicia; ED431C-2016-015Xunta de Galicia; ED431G/0

Exercise training and DNA methylation profile in post-bariatric women: Results from an exploratory study

[Abstract]: Exercise training and bariatric surgery have been shown to independently modulate DNA methylation profile in clusters of genes related to metabolic and inflammatory pathways. This study aimed to investigate the effects of a 6-month exercise training program on DNA methylation profile in women who underwent bariatric surgery. In this exploratory, quasi-experimental study, we analyzed DNA methylation levels by array technology in eleven women who underwent Roux-en-Y Gastric Bypass and a 6-month, three-times-a-week, supervised exercise training program. Epigenome Wide Association Analysis showed 722 CpG sites with different methylation level equal to or greater than 5% (P < 0.01) after exercise training. Some of these CpGs sites were related to pathophysiological mechanisms of inflammation, specially Th17 cell differentiation (FDR value < 0.05 and P < 0.001). Our data showed epigenetic modification in specific CpG sites related to Th17 cell differentiation pathway in post-bariatric women following a 6-months exercise training program.This study was supported by São Paulo Research Foundation (FAPESP) (grants #2015/18669–0, #2016/05638–1, #2017/13552–2) and Coordenação de Aperfeiçoamento de Pesquisa de Pessoal de Nível Superior - CAPES (grant #88887.473556/2020–00)

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

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 &#949;4/&#949;4 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 &#949;4/&#949;4 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