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.

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.

Green tea supplementation improves oxidative stress biomarkers and modulates IL-6 circulating levels in obese women.

INTRODUCTION: Introduction: obesity is associated with high levels of oxidative stress (OS) and inflammation. There is a lot of evidence that some polyphenols, such as green tea, have a positive impact on the OS state and consecutively, on inflammation. Objectives: the purposes of this study were: a) evaluate OS biomarkers in both obese and normal weight women; and b) evaluate if green tea supplementation has an impact on OS and inflammatory cytokine biomarkers of obese women. Methods: we evaluated obese (body mass index [BMI] ≥ 40 kg/m²) and normal weight (BMI between 18.5 and 24.9 kg/m²) women. Blood samples were used to access malondialdehyde (MDA), trolox equivalent antioxidant capacity (TEAC) and inflammatory cytokines. We randomly chose obese patients (18 individuals) and then gave them green tea supplementation for eight weeks. Statistical analysis included the Shapiro-Wilk, Wilcoxon, independent and paired t tests; p < 0.05 were considered as significant. Results: we enrolled 42 obese (BMI: 48.2 ± 9.3kg/m2) and 21 normal weight (BMI: 22.5 ± 2 kg/m2) women with an average age of 36.2 ± 9.1 years old. The serum levels of MDA were higher in obese (2.52 ± 0.31 µmol/l) than in eutrophic women (2.13 ± 0.26 µmol/l; p = 0.000). On the other hand, lower TEAC values were observed in the obese (0.75 ± 0.06 mM/l) than in the eutrophic group (0.78 ± 0.04 mM/l; p = 0.009). After the green tea intervention, MDA decreased 4.7% and TEAC increased 10%. Interleukin-6 (IL-6) serum levels decreased 12.7% after treatment (p = 0.03). Conclusions: a) the obese group had lower antioxidant capacity than eutrophic; and b) green tea supplementation ameliorated TEAC and MDA and reduced serum levels of IL-6 in obese women.

INTRODUCCIÓN: Introducción: la obesidad se asocia con altos niveles de estrés oxidativo (EO) e inflamación. Existe mucha evidencia de que algunos polifenoles, como el té verde, tienen un impacto positivo en el estado del EO y, consecutivamente, en la inflamación. Objetivos: los propósitos de este estudio fueron: a) evaluar los biomarcadores de EO en mujeres obesas y de peso normal; y b) evaluar si la suplementación con té verde tiene un impacto en el EO y biomarcadores de citoquinas inflamatorias de las mujeres obesas. Métodos: evaluamos mujeres obesas (índice de masa corporal [IMC] ≥ 40 kg/m²) y con peso normal (IMC entre 18,5 y 24,9 kg/m²). Se utilizaron muestras de sangre para determinar el malondialdehído (MDA), la capacidad antioxidante equivalente de trolox (TEAC) y las citoquinas inflamatorias. Elegimos al azar pacientes obesas (18 individuos) y luego les dimos suplementos de té verde durante ocho semanas. El análisis estadístico incluyó las pruebas de Shapiro-Wilk, Wilcoxon, t pareadas e independientes; p < 0,05 fueron considerados como significativos. Resultados: se reclutaron 42 mujeres obesas (IMC: 48,2 ± 9,3 kg/m2) y 21 de peso normal (IMC: 22,5 ± 2 kg/m2) con un promedio de edad de 36,2 ± 9,1 años. Los niveles séricos de MDA fueron más altos en las personas obesas (2,52 ± 0,31 µmol/L) que en las mujeres eutróficas (2,13 ± 0,26 µmol/L; p = 0,000). Por otro lado, se observaron valores TEAC más bajos en los obesos (0,75 ± 0,06 mM/L) que en el grupo eutrófico (0,78 ± 0,04 mM/L; p = 0,009). Después de la intervención con té verde, la MDA disminuyó 4.7% y el TEAC aumentó 10%. Los niveles séricos de interleucina-6 (IL-6) disminuyeron 12.7% después del tratamiento (p = 0,03). Conclusiones: a) mujeres obesas tienen menor capacidad antioxidante que las eutrófica; y b) la suplementación con té verde mejora TEAC y MDA y redujo los niveles séricos de IL-6 en mujeres obesas.