Genome-Wide Admixture and Association Study of Serum Selenium Deficiency to Identify Genetic Variants Indirectly Linked to Selenium Regulation in Brazilian Adults.

Blood selenium (Se) concentrations differ substantially by population and could be influenced by genetic variants, increasing Se deficiency-related diseases. We conducted a genome-wide association study (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with serum Se deficiency in 382 adults with admixed ancestry. Genotyping arrays were combined to yield 90,937 SNPs. R packages were applied to quality control and imputation. We also performed the ancestral proportion analysis. The Search Tool for the Retrieval of Interacting Genes was used to interrogate known protein-protein interaction networks (PPIs). Our ancestral proportion analysis estimated 71% of the genome was from Caucasians, 22% was from Africans, and 8% was from East Asians. We identified the SNP rs1561573 in the TraB domain containing 2B (TRABD2B), rs425664 in MAF bZIP transcription factor (MAF), rs10444656 in spermatogenesis-associated 13 (SPATA13), and rs6592284 in heat shock protein nuclear import factor (HIKESHI) genes. The PPI analysis showed functional associations of Se deficiency, thyroid hormone metabolism, NRF2-ARE and the Wnt pathway, and heat stress. Our findings show evidence of a genetic association between Se deficiency and metabolic pathways indirectly linked to Se regulation, reinforcing the complex relationship between Se intake and the endogenous factors affecting the Se requirements for optimal health.

The influence of serum selenium in differential epigenetic and transcriptional regulation of CPT1B gene in women with obesity.

INTRODUCTION: The increasing prevalence of obesity has become a major health problem worldwide. The causes of obesity are multifactorial and could be influenced by dietary patterns and genetic factors. Obesity has been associated with a decrease in micronutrient intake and consequently decreased blood concentrations. Selenium is an essential micronutrient for human health, and its metabolism could be affected by obesity, especially severe obesity. This study aimed to identify differential methylation genes associated with serum selenium concentration in women with and without obesity. METHODOLOGY: Thirty-four patients were enrolled in the study and divided into two groups: Obese (Ob) n = 20 and Non-Obese (NOb) n = 14, according to the Body Mass Index (BMI). Anthropometry, body composition, serum selenium, selenium intake, and biochemical parameters were evaluated. DNA extraction and bisulfite conversion were performed to hybridize the samples on the 450k Methylation Chip Infinium Beadchip (Illumina). Bioinformatics analysis was performed using the R program and the Champ package. The differentially methylated regions (DMRs) were identified using the Bumphunter method. In addition, logarithmic conversion was performed for the analysis of serum selenium and methylation. RESULTS: In the Ob group, the body weight, BMI, fat mass, and free fat mass were higher than in the NOb group, as expected. Interestingly, the serum selenium was lower in the Ob than in the NOb group without differences in selenium intake. One DMR corresponding to the CPT1B gene, involved in lipid oxidation, was related to selenium levels. This region was hypermethylated in the Ob group, indicating that the intersection between selenium deficiency and hypermethylation could influence the expression of the CPT1B gene. The transcriptional analysis confirmed the lower expression of the CPT1B gene in the Ob group. CONCLUSION: Studies connecting epigenetics to environmental factors could offer insights into the mechanisms involving the expression of genes related to obesity and its comorbidities. Here we demonstrated that the mineral selenium might play an essential role in lipid oxidation via epigenetic and transcriptional regulation of the CPT1B gene in obesity.

14-Week exercise training modifies the DNA methylation levels at gene sites in non-Alzheimer's disease women aged 50 to 70 years.

Exercise training emerges as a key strategy in lifestyle modification, capable of reducing the risk of developing Alzheimer's disease (AD) due to risk factors such as age, family history, genetics and low level of education associated with AD. We aim to analyze the effect of a 14-week combined exercise training (CT) on the methylation of genes associated with AD in non-alzheimer's disease women. CT sessions lasted 60 min, occurring three times a week for 14 weeks. Forty non-Alzheimer's disease women aged 50 to 70 years (60.7 ± 4.1 years) with a mean height of 1.6 ± 0.1 m, mean weight of 73.12 ± 9.0 kg and a mean body mass index of 29.69 ± 3.5 kg/m2, underwent two physical assessments: pre and post the 14 weeks. DNA methylation assays utilized the EPIC Infinium Methylation BeadChip from Illumina. We observed that 14 weeks of CT led to reductions in systolic (p = 0.001) and diastolic (p = 0.017) blood pressure and improved motor skills post-intervention. Among 25 genes linked to AD, CT induced differentially methylated sites in 12 genes, predominantly showing hypomethylated sites (negative ß values). Interestingly, despite hypomethylated sites, some genes exhibited hypermethylated sites (positive ß values), such as ABCA7, BDNF, and WWOX. A 14-week CT regimen was adequate to induce differential methylation in 12 CE-related genes in healthy older women, alongside improvements in motor skills and blood pressure. In conclusion, this study suggest that combined training can be a strategy to improve physical fitness in older individuals, especially able to induce methylation alterations in genes sites related to development of AD. It is important to highlight that training should act as protective factor in older adults.

Genetic polymorphisms related to the vitamin D pathway in patients with cirrhosis with or without hepatocellular carcinoma (HCC).

Objective: To evaluate the association of genetic polymorphisms of vitamin D transporter protein (DBPrs4588 and DBP-rs7041) and cytochrome P450-24A1 (CYP24A1-rs6013897) in patients with cirrhosis with or without hepatocellular carcinoma (HCC), including demographic/clinical/biochemical profiles. Methods: A total of 383 individuals were studied, considering the total group (TotalG) of patients with cirrhosis (TotalG: N = 158) with or without HCC, distributed into Group 1 (G1): cirrhosis and HCC; Group 2 (G2): isolated cirrhosis; and 225 individuals without hepatopathies (G3). Polymorphisms were analysed by real-time polymerase chain reaction. An alpha error of 5% was admitted. Results: CYP24A1-rs6013897 predominated the genotype with at least one polymorphic allele (_/T) in G1 (98.3%) versus G2 (88.8%; p = 0.0309). There was a moderate positive correlation between vitamin D and parathyroid hormone in patients (TotalG: R 2 = 0.3273). Smoking, alcoholism and diabetes mellitus (DM) stood out as independent factors for cirrhosis, as well as for cirrhosis with HCC, except for smoking, adding, in this case, advanced age, male gender, polymorphic allele of CYP24A1-rs6013897, viral hepatitis and high levels of serum gamma-glutamyl transferase (GGT), alpha-fetoprotein (AFP) and creatinine. An increase in survival was observed in the presence of the polymorphic allele of DBP-rs7041 (p = 0.0282). Conclusion: CYP24A1-rs6013897 is associated with cirrhosis and HCC as a predictor, while DBP-rs4588 is associated with reduced vitamin D, and DBP-rs7041 provides increased survival, suggesting a protective characteristic. Advanced age, alcoholism, DM, viral hepatitis and high levels of GGT, AFP and creatinine are also confirmed as predictors of HCC and cirrhosis, while smoking, alcoholism and DM for isolated cirrhosis only.

Sample Preparation to Bioinformatics Analysis of DNA Methylation: Association Strategy for Obesity and Related Trait Studies.

Obesity is directly connected to lifestyle and has been associated with DNA methylation changes that may cause alterations in the adipogenesis and lipid storage processes contributing to the development of the disease. We demonstrate a complete protocol from selection to epigenetic data analysis of patients with and without obesity. All steps from the protocol were tested and validated in a pilot study. 32 women participated in the study, in which 15 individuals were classified with obesity according to Body Mass Index (BMI) (45.1 ± 5.4 kg/m2); and 17 individuals were classified without obesity according to BMI (22.6 ± 1.8 kg/m2). In the group with obesity, 564 CpG sites related to fat mass were identified by linear regression analysis. The CpG sites were in the promoter regions. The differential analysis found 470 CpGs hypomethylated and 94 hypermethylated sites in individuals with obesity. The most hypomethylated enriched pathwayswere in the RUNX, WNT signaling, and response to hypoxia. The hypermethylated pathways were related to insulin secretion, glucagon signaling, and Ca2+. We conclude that the protocol effectively identified DNA methylation patterns and trait-related DNA methylation. These patterns could be associated with altered gene expression, affecting adipogenesis and lipid storage. Our results confirmed that an obesogenic lifestyle could promote epigenetic changes in human DNA.

DRD2 and BDNF polymorphisms are associated with binge eating disorder in patients with weight regain after bariatric surgery.

AIM: The aim of this study was to analyze the association and susceptibility of Single Nucleotide Polymorphisms (SNPs) in the DRD2 and BDNF genes with BED in patients with weight regain in the postoperative period of bariatric surgery. METHODS: One hundred and seventy-seven individuals who underwent bariatric surgery with weight regain were evaluated and divided into two groups according to the BED diagnostic. The individuals were submitted to an anthropometric evaluation, analysis of the presence of BED using a validated questionnaire, and blood collection for genotyping of the polymorphisms rs6265 (BDNF) and rs1800497 (DRD2) by real-time polymerase chain reaction (RT-PCR). RESULTS: The presence of wild-type alleles for rs1800497 (CC) and rs6265 (GG) was more frequent in patients without BED. Nevertheless, the presence of one or two variant alleles for rs1800497 (CT + TT) and rs6265 (GA + AA) was more frequent in patients with BED. The combination of the two studied SNPs prevailed in patients with BED. CONCLUSIONS: The presence of allele frequency of rs1800497 SNP in the DRD2 gene and rs6265 SNP in the BDNF gene, isolated and/or combined, indicated an additional risk for the development of BED in patients with obesity, especially in the context of weight regain. LEVEL OF EVIDENCE: III (evidence obtained from the case-control analytic study).

The Impact of Gastric Bypass on Telomere Length and Shelterin Complex Gene Expression: 6 Months Prospective Study.

BACKGROUND: Telomeres are structures located at the ends of chromosomes associated with a protein complex, known as the shelterin complex. In individuals with obesity, excess adipose tissue plays a key role in inducing a chronic and systemic inflammatory state, which can cause TL shortening. In this context, bariatric surgery is one of the most effective treatment modalities in improving metabolic control. AIM: Therefore, the present study aimed to evaluate how a short postoperative period of gastric bypass affects TL and expression of POT1, TRF1 and TRF2 genes. METHODS: Forty-eight women submitted to RYGB were evaluated before and after 6 months of the surgical procedure. Anthropometric measures of body weight and height (BMI), abdominal circumference (AC), body composition, food intake and blood collection for biochemical evaluation, TL analysis (DNA), and gene expression (RNA) were collected at each moment. RESULTS: There was a reduction of weight, BMI, AC, FM and FFM as well as of glycemia, total cholesterol, LDL-cholesterol, and triglycerides after gastric bypass. No difference in energy intake and macronutrients consumption was observed. There was no significant change in TL, but there was a significant increase of POT1 and TRF1 gene expression after surgery, while TRF2 expression did not change. CONCLUSIONS: Despite bariatric surgery is not capable of increasing telomere length in a short-term period, no reduction is observed; additionally, we found a correlation between serum triglycerides concentration and TL. The increase of POT1 and TRF1 gene expression may explain the maintenance of the TL after 6 months postoperative period.

Nutritional Status of Children from Women with Previously Bariatric Surgery.

BACKGROUND: Number of pregnancies has been increasing in women of childbearing age after the gastric bypass. OBJECTIVE: The objective of this study was to evaluate the nutritional status of children of women submitted to gastric bypass. METHODS: We evaluated anthropometric, breastfeeding and biochemical profile, body composition, and dietary intake indicators of children of both sexes who were born alive after the surgery. For statistical analysis, were performed Shapiro-Wilk and ANOVA test (p < 0.05). RESULTS: The sample consisted of 13 children (61.6% female, mean age of 46 ± 22.3 months, BMI of 18.9 ± 3.3 kg/m2). The classification of BMI index by age showed that 46.1% of the children were normal weight and 30.8% obese. We observed a large percentage of children with deficiency of iron and vitamin A. 7.6 and 30.7% of children presented carbohydrate and lipid, respectively, lower than the recommendation. Fiber intake was inadequate in all children, calcium in 61.5%, vitamin A in 30.7%, and folate in 76.9% of them. Also, 84.6% presented sodium intake higher than the recommendations. The blood glucose levels were lower in children with maternal breastfeeding (65.5 ± 2.1 mg/dL, p < 0.05); furthermore, children breastfed with artificial and breast milk presented lower fat mass (3.8 ± 1.9 kg; p < 0.05). CONCLUSION: Children from women with previously gastric bypass presented low birth weight; however, they are currently underweight or overweight and present important deficiency of iron and vitamin A and inadequate alimentary intake mainly of sodium and fibers. Breastfeeding may play a protective role in the development of obesity in these children.

Influence of Apolipoprotein E on the Lipid Profile and Postprandial Triglyceride Levels in Brazilian Postmenopausal Women With Artery Disease.

This study confirms the association of risk factors for coronary artery disease (CAD) and the apoE polymorphisms, specifically related to the APOE*4 allele, with coronary disease in postmenopausal women. Significantly altered values of the lipid profile were found in patients when compared with controls, independent of the presence of the APOE*4 allele. However, the controls showed higher high-density lipoprotein cholesterol (HDL-C) levels and reduced triglyceride (TG) levels, differing significantly from patients. In this case, the study of subgroups, considering the APOE*3/3 and APOE*3/4 genotypes, suggests that the APOE*4 allele is not implicated in the variations of the lipid profile of patients and determined an increase in the production levels of HDL-C and a reduction in TG highly benefiting the control group compared with APOE*3/3 genotype. The metabolic kinetics of TG, although with the same pattern between groups, and the presence of the APOE*4 allele are suggested to be associated with accelerated clearance compared with APOE*3 allele in non-CAD group.

Pregnancy After Roux en Y Gastric Bypass: Nutritional and Biochemical Aspects.

INTRODUCTION: Although pregnancy after bariatric surgery is related to risk reduction, nutritional complications may occur. This study aimed to evaluate nutritional and biochemical indicators of women who became pregnant after Roux en Y gastric bypass (RYGB). MATERIALS AND METHODS: We carried out a retrospective study with women who became pregnant after RYGB. We evaluated anthropometric, biochemical, and dietary intake indicators in the preoperative period and before, during, and after pregnancy by analysis of medical records. Shapiro-Wilk test and ANOVA for repeated measures were performed (p < 0.05). RESULTS: The study included 25 patients (35.7 ± 3.8 years), who became pregnant 31.3 ± 21.7 months after RYGB. Weight loss until the beginning of pregnancy was 32.4%, and the gestational weight gain was 3.8 ± 12 kg. There was a higher frequency of patients with hypertension in the preoperative time when compared to that during the pregnancy period. Total cholesterol (180.9 ± 24.8 versus 148.5 ± 30.4 mg/dL), LDL-cholesterol (103.5 ± 19.2 versus 85.8 ± 23.1 mg/dL), HDL-cholesterol (56.4 ± 8 versus 46.9 ± 8.7 mg/dL), and latent iron-binding capacity (337.6 ± 95.8 versus 277.8 ± 65 µg/dL) were higher during the pregnancy compared to that before the pregnancy, while hemoglobin values (11.2 ± 1 versus 12.3 ± 1.2 g/dL) and sodium (138.8 ± 2.9 versus 141 ± 3 mmol/L) were lower. No differences of food intake were found among times. There is no difference on gestational weight gain between women who became pregnant before or after the first year. CONCLUSION: During pregnancy, there was an expected weight gain and maintenance of the lipid profile within the normal range; however, there was a reduction of hemoglobin levels. These findings show the need for individualized follow-up with adequate nutritional intervention in the event of deficiencies.

UCP2 and PLIN1 Expression Affects the Resting Metabolic Rate and Weight Loss on Obese Patients.

BACKGROUND: Analysis of the expression of genes related to the energy metabolism can elucidate the understanding of physiological and genetic factors that contribute to obesity. This study aimed to evaluate the expression of genes and its influence on resting metabolic rate and weight loss in obese patients before and after bariatric surgery. METHODS: This study was conducted on 23 women, who were divided into two groups: bariatric surgery (preoperative and 6 months after surgery) and control. Abdominal subcutaneous adipose tissue samples were collected to analyze the gene expression, and the resting metabolic rate (RMR) was measured by indirect calorimetry. RESULTS: Significant differences were observed in weight reduction (22 %, p = 0.01), BMI (22.5 %, p = 0.01), and RMR values (10.5 %, p = 0.01) after the bariatric surgery, while the weight-adjusted RMR increased (15.8 %, p = 0.01). Increased UCP2 expression after 6 months of Roux-en-Y gastric bypass (RYGB) as compared to preoperative period (0.764 to 1.268, p = 0.01) was observed. Analysis with weight-adjusted RMR as dependent variable revealed that UCP2 (r 2 = 0.517, p = 0.01) and PLIN1 (r 2 = 0.420, p = 0.04) expression determine the RMR values in preoperative period. Moreover, UCP2 and PLIN1 expression in preoperative period influenced the percentage of weight loss, even when adjusted for age and BMI. CONCLUSIONS: We have demonstrated that after 6 months of bariatric surgery, there is significant increase in the UCP2 expression. Additionally, the expression of UCP2 and PLIN1 genes influences the resting metabolic rate in obese individuals and could predict the weight loss after bariatric surgery.

Angiotensin-converting enzyme insertion/deletion polymorphism, 24-h blood pressure profile and left ventricular hypertrophy in hypertensive individuals: a cross-sectional study.

BACKGROUND: The absence of nocturnal blood pressure dipping (ND) identified by 24-h ambulatory blood pressure monitoring (ABPM) correlates with a worse cardiovascular prognosis. The renin-angiotensin system influences blood pressure levels and the occurrence of target organ damage (TOD). Thus, the aim of this study was to correlate the angiotensin-converting enzyme gene (ACE) insertion/deletion (I/D) polymorphism with the 24-h blood pressure profile and TOD in hypertensive individuals. METHODS: 155 non-diabetic hypertensive individuals on antihypertensive treatment underwent ABPM. Peripheral blood samples were drawn for biochemistry and genetic analysis of the ACE I/D polymorphism by polymerase chain reaction. ND was defined as ≥10 % differences in the mean systolic blood pressure (BP) during wakefulness and sleep. RESULTS: There were no differences in clinical or biochemical variables or TOD in respect to ND status, except for higher BP levels during sleep (p < 0.001) in non-dippers. There was significant difference in the prevalence of left ventricular hypertrophy (LVH) between ACE genotypes (II: 13.0 %; ID: 34.1 %; DD: 46.5 %; p value = 0.024) with an increased risk in carriers of the DD genotype (OR = 5.80; IC 95 % 1.50-22.44; p value = 0.011). Carriers of the D allele had higher systolic BP during wakefulness and by ABPM (p < 0.05), higher left ventricular mass (117.3 ± 50.0 vs. 100.3 ± 25.7; p value = 0.017) and higher prevalence of LVH (37.4 vs. 12.5 %; OR = 4.14; 95 % IC: 1.17-14.65; p value = 0.028), compared to the II genotype. CONCLUSIONS: The DD genotype is associated with a higher prevalence of LVH. The presence of the D allele appears to be associated with higher mean 24-h and wake systolic BP measured by ABPM in hypertensive patients under antihypertensive treatment.

Association of interleukin 1ß polymorphisms and haplotypes with Alzheimer's disease.

Our study aimed to associate IL-1ß and IL-1RN polymorphisms with AD disease in comparison with elderly control group from São Paulo - Brazil. We genotyped 199 Alzheimer's disease (AD) patients, 165 elderly control and 122 young control samples, concerning VNTR (IL-1RN) and -511C>T and -31T>C (IL-1ß) polymorphisms. Our findings revealed that -511C/-31T/2-repetitions VNTR haplotype had a protective effect for AD when compared to EC (p=0.005), whereas -511C/-31C/1-repetition VNTR haplotype was associated as a risk factor for AD (p=0.021). Taken together, we may suggest that there is a relevant role of IL-1 genes cluster in AD pathogenesis in this Brazilian population.

Association of ApoE genetic polymorphisms with proximal deep venous thrombosis.

The aim of the current study was to evaluate a possible association between apolipoprotein E (ApoE) genetic polymorphisms and deep venous thrombosis. A case-control study of ApoE genetic polymorphisms was carried out in 60 male and female patients with deep venous thrombosis and 60 male and female controls. The ages of the patients ranged between 23 and 90 years old (mean ± standard deviation: 58 ± 16.56 years) and the ages of the control group, varied between 21 and 56 years old (mean ± SD: 33 ± 10.93 years). Genetic polymorphisms were analyzed in respect to the prevalence of alleles (APOE*2, APOE*3 and APOE*4) and genotypes (APOE*2/2, APOE*2/3, APOE*2/4, APOE*3/3, APOE*3/4 and APOE*4/4). The ε2 allele was more common in patients who had suffered thrombotic events (P = 0.0034). Additionally, there was a significant difference on comparing the distribution of alleles in female patients and female controls (P = 0.027). These results demonstrate an association between the ApoE ε2 allele and deep venous thrombotic events in women. This association opens the possibility of a new line of research to better understand these thrombotic events.

Interleukin-8-251T > A, Interleukin-1α-889C > T and Apolipoprotein E polymorphisms in Alzheimer's disease.

An inflammatory process has been involved in numerous neurodegenerative disorders such as Parkinson's disease, stroke and Alzheimer's disease (AD). In AD, the inflammatory response is mainly located in the vicinity of amyloid plaques. Cytokines, such as interleukin-8 (IL-8) and interleukin-1α (IL-1α), have been clearly involved in this inflammatory process. Polymorphisms of several interleukin genes have been correlated to the risk of developing AD. The present study investigated the association of AD with polymorphisms IL-8 -251T > A (rs4073) and IL-1α-889C > T (rs1800587) and the interactive effect of both, adjusted by the Apolipoprotein E genotype. 199 blood samples from patients with AD, 146 healthy elderly controls and 95 healthy young controls were obtained. DNA samples were isolated from blood cells, and the PCR-RFLP method was used for genotyping. The genotype distributions of polymorphisms IL-8, IL-1α and APOE were as expected under Hardy-Weinberg equilibrium. The allele frequencies did not differ significantly among the three groups tested. As expected, the APOE4 allele was strongly associated with AD (p < 0.001). No association of AD with either the IL-1α or the IL-8 polymorphism was observed, nor was any interactive effect between both polymorphisms. These results confirm previous studies in other populations, in which polymorphisms IL-8 -251T > A and IL-1α-889C > T were not found to be risk factors for AD.

LRRK2 p.G2019S mutation is not common among Alzheimer's disease patients in Brazil.

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene have emerged as a potential common cause for both sporadic and familial Parkinson's Disease (PD) in different populations. The pleomorphic features exhibited by LRRK2 mutation carriers and the central role of Lrrk2 protein in the proper functioning of central nervous system suggest that mutations in this protein might be involved in multiple cellular processes leading to other neurodegenerative disorders than PD. The location of LRRK2 gene on chromosome 12, close to a linkage peak for familial late-onset Alzheimer's Disease (AD), highlights that LRRK2 mutations might be involved in AD pathogenesis. We screened the most common LRRK2 mutation (p.G2019S) in a series of 180 consecutive patients clinically diagnosed with Alzheimer Disease (AD). We identified the p.G2019S in one AD patient with no PD signs, indicating that this mutation is not a common etiological factor for AD in our population (0.5%), corroborating recent data found in Norwegian, North American, Chinese and Italian populations. Nevertheless, these observations together with new information about the Lrrk2 critical multifunctionality do not rule out the possible influence of other variants within LRRK2 in AD, so that other screenings focusing in the whole extension of the LRRK2 using larger sized confirmed AD sample are urgently needed.