Percentage Of DNA Methylation Research Articles

Hypomethylation of the IL8 promoter in nasal epithelial cells of patients with chronic rhinosinusitis with nasal polyps

IL-8 is an important chemokine implicated in the pathogenesis of chronic rhinosinusitis (CRS), but little is known about epigenetic regulation of IL8 in the pathogenesis of CRS. We sought to investigate the relationship between the DNA methylation level in the IL8 proximal promoter and CRS in Han Chinese subjects. Patients with chronic rhinosinusitis with nasal polyps (CRSwNP; n=187), patients with chronic rhinosinusitis without nasal polyps (CRSsNP; n=89), and control subjects (n=57) were enrolled in 2 independent cohorts. Purified human nasal epithelial cells from each participant were assessed for percentage DNA methylation of CpG sites in the IL8 proximal promoter by using bisulfite pyrosequencing and for functional aspects of methylation status by using invitro assays. DNA methylation of CpG sites 1, 2, and 3, respectively, in the IL8 proximal promoter was significantly decreased in human nasal epithelial cells of patients with CRSwNP compared with that in patients with CRSsNP (P<.001) and control subjects (P<.001). Percentage of DNA methylation of the CpG3 site was correlated negatively with both tissue eosinophilic cationic protein (P<.01) and myeloperoxidase (P<.05) levels. IL-1β (P<.001) and TNF-α (P<.01) significantly increased IL8 expression accompanied by a reduction in methylation at the CpG3 site (P<.001). Electrophoretic mobility shift assays demonstrated that methylation status of CpG3 changed the binding of octamer-binding transcription factor 1 and nuclear factor κB. Decreased DNA methylation of particularly CpG sites in the IL8 proximal promoter might play a role in the pathogenesis of CRSwNP.

Regulation of adenosine A2A receptor gene expression in a model of binge eating in the amygdaloid complex of female rats.

Pharmacological treatment approaches for eating disorders, such as binge eating disorder and bulimia nervosa, are currently limited. Using a well-characterized animal model of binge eating, we investigated the epigenetic regulation of the A2A Adenosine Receptor (A2AAR) and dopaminergic D2 receptor (D2R) genes. Gene expression analysis revealed a selective increase of both receptor mRNAs in the amygdaloid complex of stressed and restricted rats, which exhibited binge-like eating, when compared to non-stressed and non-restricted rats. Consistently, pyrosequencing analysis revealed a significant reduction of the percentage of DNA methylation but only at the A2AAR promoter region in rats showing binge-like behaviour compared to the control animals. Focusing thus on A2AAR agonist (VT 7) administration (which inhibited the episode of binge systemically at 0.1 mg/kg or intra-central amygdala (CeA) injection at 900 ng/side) induced a significant increase of A2AAR mRNA levels in restricted and stressed rats when compared to the control group. In addition, we observed a significant decrease in A2AAR mRNA levels in rats treated with the A2AAR antagonist (ANR 94) at 1 mg/kg. Consistent changes in the DNA methylation status of the A2AAR promoter were found in restricted and stressed rats after administration of VT 7 or ANR 94. We confirm the role of A2AAR in binge eating behaviours, and we underline the importance of epigenetic regulation of the A2AAR gene, possibly due to a compensatory mechanism to counteract the effect of binge eating. We suggest that A2AAR activation, inducing receptor gene up-regulation, could be relevant to reduction of food consumption.

PF540 TERT PROMOTER METHYLATION AS A POTENTIAL PROGNOSTIC BIOMARKER FOR PROGRESSION OF UNEXPLAINED CYTOPENIA TO MDS AND AML

Background:Patients with myelodysplastic syndrome (MDS) often have mutations in epigenetic regulators and altered DNA methylation in their blood cells. Patients with unexplained cytopenia that do not fulfill the criteria for MDS are referred to as having idiopathic cytopenia of undetermined significance (ICUS) or, if they have MDS‐related mutations, clonal cytopenia of undetermined significance (CCUS).A previous study (Zhao et al. BJH 2016) showed that acute myeloid leukemia (AML) patients with preceding MDS (MDS/AML) have hypermethylation of the telomerase reverse transcriptase (TERT) promoter compared to healthy controls. Increased TERT promoter methylation may cause impaired telomerase activity and thereby shortening of telomeres and increased risk of progression to AML.Aims:We aimed to investigate DNA methylation of the TERT promoter to evaluate its potential as a biomarker of disease severity in patients with unexplained cytopenia and MDS.Methods:TERT promoter methylation of two regions (region 1 covering 5 CpG sites 456 to 424 bp upstream of the TSS and region 2 covering 6 CpG sites 384 to 328 bp upstream of the TSS) was analyzed by pyrosequencing in a cohort of 185 patients with ICUS (n = 65), CCUS (n = 49) or MDS (n = 71). Results are presented as DNA methylation percentage of region 1 and 2 (mean ± SD).Results:The 185 included patients (111 men, 74 women) had a median age of 69 years (ICUS: 65 years, CCUS: 70 years, MDS: 72 years) and the 15 healthy controls (6 men, 7 women) had a median age of 57 years.One‐way ANOVA analysis revealed significantly differences in TERT promoter methylation between all groups for both regions (region 1: p = 0.0004, region 2: p = 7.4 × 10–5).TERT promoter methylation in region 1 was significantly higher in all disease groups compared to healthy controls, with increasing methylation and significance levels with increased disease severity (ICUS: 8.3 ± 4.8, p = 0.03; CCUS: 10.2 ± 7.2, p = 0.0007, MDS: 11.3 ± 7.7, p = 1.9 × 10–6; Figure 1A). Furthermore, TERT promoter methylation levels of both CCUS and MDS patients were significantly higher than ICUS patients (p = 0.02 and p = 1.8 × 10–6, respectively.In region 2, MDS patients had significantly higher methylation (MDS: 8.8 ± 8.1, p = 0.001) compared to healthy controls (5.4 ± 3.2). TERT promoter methylation of region 2 in ICUS and CCUS patients was not significantly different from healthy controls or MDS patients (Figure 1B).Figure 1: Box‐and‐whisper plots of TERT promoter methylation percentage in region 1 (A) and region 2 (B) in 185 ICUS, CCUS, MDS patients and 15 age‐matched healthy controls.Summary/Conclusion:Promoter methylation of TERT increases gradually from healthy controls to ICUS, CCUS and MDS patients. Our study suggests that DNA methylation of the TERT promoter reflects disease severity of unexplained cytopenia and MDS patients. We are currently investigating if TERT promoter methylation can be used as a biomarker for survival and progression to MDS and AML.image

Global DNA Methylation in the Limbic System of Cattle.

To elucidate the extent to which DNA methylation varies across multiple tissues in the brain and between animals, we have quantified global DNA methylation in tissues comprising the limbic system for six Red Angus x Simmental steers. Global DNA methylation was measured in nine regions of the bovine brain: amygdala, the bed nucleus of the stria terminalis, cingulate gyrus, dorsal raphe, hippocampus, hypothalamus, nucleus accumbens, periaqueductal gray and prefrontal cortex. DNA methylation varies among animals for each tissue type and varies among tissue types for each animal. The highest amounts of DNA methylation were found in the amygdala, cingulate gyrus and dorsal raphe, while the bed nucleus of the stria terminalis, nucleus accumbens and periaqueductal gray had the lowest amounts of DNA methylation. A heatmap sorted by k-means clustering was generated to graphically display percent DNA methylation in relation to tissue type and animal number. This is the first study to report measures of DNA methylation in the limbic system of the bovine brain and can be used to inform the cattle genomics community of expected variation in cattle brain methylation.

Assessing Global DNA Methylation Changes Associated with Plasticity in Seven Highly Inbred Lines of Snapdragon Plants (Antirrhinum majus).

Genetic and epigenetic variations are commonly known to underlie phenotypic plastic responses to environmental cues. However, the role of epigenetic variation in plastic responses harboring ecological significance in nature remains to be assessed. The shade avoidance response (SAR) of plants is one of the most prevalent examples of phenotypic plasticity. It is a phenotypic syndrome including stem elongation and multiple other traits. Its ecological significance is widely acknowledged, and it can be adaptive in the presence of competition for light. Underlying genes and pathways were identified, but evidence for its epigenetic basis remains scarce. We used a proven and accessible approach at the population level and compared global DNA methylation between plants exposed to regular light and three different magnitudes of shade in seven highly inbred lines of snapdragon plants (Antirrhinum majus) grown in a greenhouse. Our results brought evidence of a strong SAR syndrome for which magnitude did not vary between lines. They also brought evidence that its magnitude was not associated with the global DNA methylation percentage for five of the six traits under study. The magnitude of stem elongation was significantly associated with global DNA demethylation. We discuss the limits of this approach and why caution must be taken with such results. In-depth approaches at the DNA sequence level will be necessary to better understand the molecular basis of the SAR syndrome.

Effects of bisphenol-A and folic acid on growth, reproductive development, and DNA methylation in snapdragons (Antirrhinum majus)

Bisphenol-A (BPA), used in the production of polycarbonate plastics, exerts complex effects on the development of organisms and on their epigenomes as a methylation disruptor. BPA is of concern due to its ubiquity in the environment. In contrast, folic acid can promote plant growth and has been shown to correct the methyl-disrupting effects of BPA in mice. We investigated the effects of prolonged exposure to BPA and folic acid on plant height, dry mass, and DNA methylation of floral tissues of Antirrhinum majus L. (snapdragons) from seedling to floral senescence. At low and medium concentrations (5 and 25 mg/L), BPA had a growth-promoting effect early in development and appeared to accelerate floral development compared with the controls. At senescence, plants treated with the low and medium concentrations of BPA had decreased dry mass compared with the controls. Folic acid promoted growth early through mid-vegetative development and also promoted early flowering. In general, the acceleration of floral development associated with the low concentration of BPA and folic acid correlated with higher DNA methylation percentages. These data suggest that prolonged exposure to BPA influences plant growth and floral development, and causes epigenetic modifications that may potentially be alleviated through the application of folic acid, thus suggesting the significance of folic acid for environmental protection.

Global DNA Methylation in Children with Complicated Urinary Tract Infection

Background and Objectives: The Study suggests that pathogen interceded DNA methylation changes influence the gene expression pattern contributing to disease progression. To study the association between pathogen-induced global DNA methylation variation in children with complicated Urinary tract infection and healthy children. Methods: The study was conducted in the Department of Pediatrics of a referral hospital. For this study, 50 children as cases with complicated UTI and 50 healthy children as controls were enrolled. Whole blood genomic DNA was isolated from the cases as well as controls. Using 5-mC (methylcytosine) DNA ELISA method, the percentage of genomic DNA methylation in these children was established. Results: Global DNA methylation level was found highly significant between cases and controls and the percentage of DNA methylation level was (Cases: 25.81 ± 6.9; Controls: 15.354 ± 3.17; P<0.001). Receiver operating curve analysis showed that the area under curve 0.92 for the total study population. Interpretation and conclusions: The results of this study show that genomic DNA methylation varies significantly among cases and controls. This study points towards the role of DNA methylation in the pathogenesis of complicated urinary tract infection.

DNA methylation of FKBP5 and response to exposure-based psychological therapy.

Differential DNA methylation of the hypothalamic‐pituitary‐adrenal axis related gene FKBP5 has recently been shown to be associated with varying response to environmental influences and may play a role in how well people respond to psychological treatments. Participants (n = 111) received exposure‐based cognitive behavioural therapy (CBT) for agoraphobia with or without panic disorder, or specific phobias. Percentage DNA methylation levels were measured for the promoter region and intron 7 of FKBP5. The association between percentage reduction in clinical severity and change in DNA methylation was tested using linear mixed models. The effect of genotype (rs1360780) was tested by the inclusion of an interaction term. The association between change in DNA methylation and FKBP5 expression was examined. Change in percentage DNA methylation at one CpG site of intron 7 was associated with percentage reduction in severity (β = −4.26, p = 3.90 × 10−4), where a decrease in DNA methylation was associated with greater response to therapy. An interaction was detected between rs1360780 and changes in DNA methylation in the promoter region of FKBP5 on treatment outcome (p = .045) but did not survive correction for multiple testing. Changes in DNA methylation were not associated with FKBP5 expression. Decreasing DNA methylation at one CpG site of intron 7 of FKBP5 was strongly associated with decreasing anxiety severity following exposure‐based CBT. In addition, there was suggestive evidence that allele‐specific methylation at the promoter region may also be associated with treatment response. The results of this study add to the growing literature demonstrating the role of biological processes such as DNA methylation in response to environmental influences.

Brood size influences patterns of DNA methylation in wild Zebra Finches (Taeniopygia guttata)

Both natural and experimentally manipulated brood size can influence the competition dynamics among siblings in a nest and alter the environment during early development in birds. Brood size affects a variety of life-history and fitness-related traits, but relatively little is known about the mechanisms that might mediate these effects. There is accumulating evidence that early-life environments can influence adult phenotypes though epigenetic mechanisms such as variation in DNA methylation. Here, we profile DNA methylation in nestling Zebra Finches (Taeniopygia guttata) raised in naturally variable and experimentally manipulated brood sizes. We found that (1) natal brood size is significantly, positively correlated with percent DNA methylation in blood; and (2) individuals in manipulated broods experience significantly more demethylation events across early development than individuals from broods that remain the same size. Any manipulation of brood size creates fluctuations in early developmental conditions, potentially explaining why the frequency of demethylation events in these treatments was higher than in control broods. We also found that the specific loci that lost and gained methylation across early development differed between individuals in enlarged and reduced broods, which may reflect the different developmental pressures imposed by the different manipulations. Although the phenotypic consequences of reduced levels of methylation are yet to be elucidated, our findings support the hypothesis that brood size is associated with the prevalence and pattern of DNA methylation in wild birds.

Clinical Validation of PITX2 DNA Methylation to Predict Outcome in High-Risk Breast Cancer Patients Treated with Anthracycline-Based Chemotherapy

Background: Breast cancer patients at high risk for recurrence are treated with anthracycline-based chemotherapy, but not all patients do equally benefit from such a regimen. To further improve therapy decision-making, biomarkers predicting outcome are of high unmet medical need. Methods: The percent DNA methylation ratio (PMR) of the promoter gene coding for the Paired-like homeodomain transcription factor 2 (PITX2) was determined by a validated methylation-specific real-time polymerase chain reaction (PCR) test. The multicenter study was conducted in routinely collected archived formalin-fixed paraffin-embedded (FFPE) tissue from 205 lymph node-positive breast cancer patients treated with adjuvant anthracycline-based chemotherapy. Results: The cut-off for the PITX2 methylation status (PMR = 12) was confirmed in a randomly selected cohort (n = 60) and validated (n = 145) prospectively with disease-free survival (DFS) at the 10-year follow-up. DFS was significantly different between the PMR ≤ 12 versus the PMR > 12 group with a hazard ratio (HR) of 2.74 (p < 0.001) in the validation cohort and also for the patient subgroup treated additionally with endocrine therapy (HR 2.47; p = 0.001). Conclusions: Early-stage lymph node-positive breast cancer patients with low PITX2 methylation do benefit from adjuvant anthracycline-based chemotherapy. Patients with a high PITX2 DNA methylation ratio, approximately 30%, show poor outcome and should thus be considered for alternative chemotherapy regimens.

Correlating blood-based DNA methylation markers and prostate cancer risk in African-American men.

The objective of this work was to investigate the clinical significance of promoter gene DNA methylation changes in whole blood from African-American (AA) men with prostate cancer (PCa). We used high throughput pyrosequencing analysis to quantify percentage DNA methylation levels in a panel of 8 genes (RARβ2, TIMP3, SPARC, CDH13, HIN1, LINE1, CYB5R2 and DRD2) in blood DNA obtained from PCa and non-cancerous controls cases. Correlations of methylation status and various clinicopathological features were evaluated. Six genes tested achieved significant difference in DNA methylation levels between the PCa compared to control cases (P < 0.05). The TIMP3 loci demonstrated significant correlation of DNA methylation with age for all cases analyzed (p < 0.05). We observed an inverse correlation between CDH13 methylation (p = 0.045; r = -0.21) and serum vitamin D level whereas TIMP3 methylation (p = 0.021; r = -0.24) and DRD2 methylation (p = 0.056; r = -0.201) showed inverse correlation with supplementary vitamin D in the cancer cases. We also observed a direct correlation between methylation of RARβ2 (p = 0.0036; r = 0.293) and SPARC (p = 0.0134; r = 0.20) loci with PSA level in the controls but not the cancer cases. In addition, alcohol cases significantly correlated with higher RARβ2 methylation (p = 0.0314) in comparison with non-alcohol cases. Furthermore, we observed an inverse correlation of DRD2 methylation (p = 0.0349; r = -0.343) and Gleason score. Our data suggests that promoter methylation occurred more frequently in the blood of AA PCa and is associated with various clinicopathological features in AA men with PCa.

High intragenic methylation of SERPINB9, a regulator of cytotoxicity, in T cells as a marker for skin cancer after kidney transplantation

Background Skin cancer, specifically cutaneous squamous cell carcinoma (cSCC), occurs 65-200 times more frequent in organ transplant recipients than in the general population. T cells, which are targeted by immunosuppressive drugs, are important in anti-tumor immune surveillance and it is known that their function is regulated by DNA methylation. Our previous study demonstrated higher DNA methylation of an intragenic region of SERPINB9 when comparing T cells from kidney transplant recipients before the occurrence of cSCC with T cells from recipients without cSCC. SERPINB9 codes for a serine protease inhibitor that inhibits Granzyme B and is actively transcribed in T cells. We hypothesized that high methylation of SERPINB9 is a stable trait and may affect the cytotoxic activity of T cells towards cSCC cells, thereby facilitating the development of cSCC. Methods We studied a cohort of kidney transplant recipients (n=30) with recurrent cSCC and recipients without cSCC (n=26) of whom PBMCs were available, general patient characteristics were not different between the two groups. The mean time after transplantation was 13 years (±9 years). The cSCC patients developed their first biopsy-proven cSCC 7 years (±6 years) after transplantation. Peripheral T cells were characterized by the following markers: CD3, CD4, CD8, CD45RO, CCR7, CD25 and CD127. DNA methylation of two regions within SERPINB9, both containing 6 CpG sites, was measured using pyrosequencing analysis. Results No significant differences were found for the distribution of naive and memory T cell subsets and T regulatory cells between the cSCC and non-cSCC patients after cell sorting. We analyzed DNA methylation of the isolated T cells per region, which is an average of the 6 CpG sites. Percentage DNA methylation of the first region within SERPINB9 was 59%(±14%) for the cSCC patients and 51%(±13%) for the non-cSCC patients (p=0.03). The second region showed DNA methylation percentages of 55%(±14%) for the cSCC patients and 48%(±13%) for the non-cSCC patients (p=0.03). Conclusion Our results demonstrate that high intragenic methylation of SERPINB9 in T cells, previously found before the clinical onset of cSCC, can be validated in a different cohort of kidney transplant recipients during recurrent cSCC. This suggests a functional role for SERPINB9 methylation in cSCC development, possibly impairing T cells in exerting their cytotoxic activity towards cSCC cells. We conclude that high SERPINB9 methylation is stable throughout cSCC development which is a novel insight in the pathogenesis of cSCC in kidney transplant recipients.

Paternal physical exercise demethylates the hippocampal DNA of male pups without modifying the cognitive and physical development

Maternal exercise is known to have beneficial effects in progeny development, but the influence of paternal exercise on the offspring still unclear. Since spermatogenesis is a continuous process, the father’s life experiences can reprogram epigenetic content of the sperm and somehow interfere on offspring phenotype. This study was designed to evaluate the effects of paternal physical exercise on cognitive and physical development and on hippocampal DNA methylation levels of the offspring. Adult male Wistar rats were divided into two groups: sedentary and exercised. The exercise protocol occurred before mating and consisted of treadmill running, 5 consecutive days/week for 8 weeks (20 min/day). The mothers were not trained. The following developmental parameters were examined in male offspring: body growth, physical and cognitive performance, weights of adrenal glands, gonadal fat and hindlimb muscles, BDNF expression and global DNA methylation at the hippocampus. The progeny of trained and sedentary fathers did not differ in relation to physical parameters and performance, spatial memory and BDNF expression. However, paternal exercise promoted a decrease in offspring´s relative gonadal fat weight and a lower percentage of global hippocampal DNA methylation compared to offspring of sedentary fathers. These results pointed to interference of male physical activity at the time of conception on adiposity and hippocampal epigenetic reprogramming of male offspring. The data reinforces that exercise does not harm the descendant’s development and emphasize the benefits to include the practice of physical exercise in a healthier lifestyle of the parents. Nevertheless, future studies are necessary and should investigate further the long-effects of epigenetic mechanisms in order to elucidate the father’s contribution in fetal programming.

Shorter telomere length and DNA hypermethylation in peripheral blood cells of coal workers

Coal is a mixture of several chemicals, mainly inorganic elements and polycyclic aromatic hydrocarbons, many of which have mutagenic and carcinogenic effects. Pneumoconiosis, fibrosis, asbestosis, silicosis, emphysema, loss of lung function and cancer are some examples of coal-related disorders. The aim of this study was to analyze coal miners with respect to telomere length (TL) and percentage (%) of global DNA methylation. The study involved 82 participants divided into two groups: 55 workers exposed to coal and 27 non-exposed individuals. DNA was isolated from peripheral blood samples from all individuals. Telomeres were measured by quantitative real time polymerase chain reaction (qPCR) and global DNA methylation levels were performed by the relative quantitation of 5-methyl-2′-deoxycytidine (5-mdC) by high-performance liquid chromatography (HPLC). TL measurements showed a mean of 9,199 bp (±4,196) for non-exposed and 7,545 bp (±2,703) for exposed groups, and% of global DNA methylation a mean of 2.78% (±0.41) for non-exposed and 3.00% (±0.37) for exposed individuals. Occupationally exposed individuals showed a significant decrease of TL (P < 0.05; Mann-Whitney test) and increase in the percentage of global DNA methylation (P < 0.05; Mann-Whitney test) when compared to the non-exposed group. This study showed that occupational exposure to coal and products of combustion is positively associated with TL and DNA methylation. Previously, we have evaluated the same individuals using comet assay, micronucleus (MN) test, oxidative stress and inorganic elements. No correlations were observed between TL and methylation with previous data in the exposed group. Further studies are needed to determine whether these alterations are associated with induced disease outcomes and if these events could be determinants to identify cancer risk.

Human Lung DNA Methylation Quantitative Trait Loci Colocalize with Chronic Obstructive Pulmonary Disease Genome-Wide Association Loci.

As the third leading cause of death in the United States, the impact of chronic obstructive pulmonary disease (COPD) makes identification of its molecular mechanisms of great importance. Genome-wide association studies (GWASs) have identified multiple genomic regions associated with COPD. However, genetic variation only explains a small fraction of the susceptibility to COPD, and sub-genome-wide significant loci may play a role in pathogenesis. Regulatory annotation with epigenetic evidence may give priority for further investigation, particularly for GWAS associations in noncoding regions. We performed integrative genomics analyses using DNA methylation profiling and genome-wide SNP genotyping from lung tissue samples from 90 subjects with COPD and 36 control subjects. We performed methylation quantitative trait loci (mQTL) analyses, testing for SNPs associated with percent DNA methylation and assessed the colocalization of these results with previous COPD GWAS findings using Bayesian methods in the R package coloc to highlight potential regulatory features of the loci. We identified 942,068 unique SNPs and 33,996 unique CpG sites among the significant (5% false discovery rate) cis-mQTL results. The genome-wide significant and subthreshold (P < 10-4) GWAS SNPs were enriched in the significant mQTL SNPs (hypergeometric test P < 0.00001). We observed enrichment for sites located in CpG shores and shelves, but not CpG islands. Using Bayesian colocalization, we identified loci in regions near KCNK3, EEFSEC, PIK3CD, DCDC2C, TCERG1L, FRMD4B, and IL27. Colocalization of mQTL and GWAS loci provides regulatory characterization of significant and subthreshold GWAS findings, supporting a role for genetic control of methylation in COPD pathogenesis.

Assessment of global DNA methylation in children with tuberculosis disease

Studying DNA methylation changes in disease condition provides the basis of disease pathogenesis or host immune response to infection. Evidences suggest that pathogen-mediated DNA methylation changes influences the expression pattern of genes contributing to disease condition to avert host immune response. Hence, we attempted to study the association between tubercle bacilli-mediated global DNA methylation changes in children with tuberculosis (TB) disease and healthy controls. Forty-three children diagnosed with TB and 33 healthy children were enrolled in this study. ELISA-based global DNA methylation quantification was performed to measure the changes in percentage of global genomic DNA methylation level. Highly significant difference in global DNA methylation level was found between cases and controls and median global DNA methylation level was 6.25% (interquartile range [IQR] 2.5%-10%) in cases and 25% (IQR, 12.5%-25%) in controls (P < 0.001). Significant difference was found in GeneXpert-positive cases (P < 0.01). Receiver operating curve analysis showed that area under curve 0.81 for the total study population and 0.76 for GeneXpert-positive cases. The results show the significant difference in global DNA methylation level in children with TB disease that can serve as a potential biomarker in early diagnosis of TB disease. Measuring global DNA methylation level, however, not an accurate or sensitive diagnostic method but evaluating active demethylation at genome-wide level can be used to monitor disease progression and treatment efficacy.

MaFOS-GDM trial: Maternal fish oil supplementation in women with gestational diabetes and cord blood DNA methylation at insulin like growth factor-1 (IGF-1) gene

To evaluate the effects of maternal fish oil supplementation in women with gestational diabetes mellitus (GDM) on birthweight and DNA methylation at insulin like growth factor-1 (IGF-1) gene in their offspring. Randomized controlled trial. A total of 120 women with GDM were randomized to one of the two groups between 24 and 28 weeks of the pregnancy: Group 1 (n=52) received fish oil liquid softgel (Ocean plus®) and Group 2 (Placebo) (n=68) sunflower oil liquid softgel. The birthweight and DNA methylation at IGF-1 gene of the offsprings were assessed. We observed a significant inverse association between fish oil use during pregnancy and birthweight (β=-0.18, s.e.:125, P=.04), corresponding to a 250g lower birthweight among infants born to fish oil users. This association didn't persist in multivariate analysis. Cord blood IGF-1 was lower in fish oil group (P=.001). Cord blood DNA methylation percentages at CpG-1044 and CpG-611 sites of IGF-1 gene promoter 1 (P1) region were higher in fish oil group compared to placebo group (P=.02 and P=.001, respectively). However, CpG-1044 and CpG-611 methylations were not associated to birthweight (β=0.04, s.e: 25.1, P=.66 and β=0.04, s.e: 22.7, P=0.66, respectively). Maternal fish oil use has small effects on birthweight and DNA methylation when given to mothers with GDM at late pregnancy. Future studies are needed to show associations between maternal fish oil use and neonatal DNA methylations. "Fish Oil Supplementation in Women with Gestational Diabetes". NCT02371343.

DNA methylation alterations induced by transient exposure of MCF-7 cells to maghemite nanoparticles.

To evaluate the DNA methylation profile of MCF-7 cells during and after the treatment with maghemite nanoparticles (MNP-CIT). Noncytotoxic MNP-CIT concentrations and cell morphology were evaluated by standard methods. DNA methylation was assessed by whole genome bisulfite sequencing. DNA methyltransferase (DNMT) genes expression was analyzed by qRT-PCR. A total of 30 and 60µgFeml-1 MNP-CIT accumulated in cytoplasm but did not present cytotoxic effects. The overall percentage of DNA methylation was not affected, but 58 gene-associated regions underwent DNA methylation reprogramming, including genes related to cancer onset. DNMT transcript levels were also modulated. Transient exposure to MNP-CIT promoted epigenomic changes and altered the DNMT genes regulation in MCF-7 cells. These events should be considered for biomedical applications.

Lead (Pb) exposure induces disturbances in epigenetic status in workers exposed to this metal

ABSTRACTPrevious studies showed that lead (Pb) exposure may modulate gene expression by changes in the epigenetic status. However, little is known about the impact of Pb exposure and alterations on DNA methylation patterns in humans exposed to this metal. The aim of this study was to assess the consequences of exposure to Pb on DNA global methylation, in order to gain a better understanding of the interactions between Pb exposure and epigenetic effects. The study included 100 male workers employed in automotive battery factories from Paraná State, Brazil. Concentrations of Pb in blood (B-Pb) and plasma (P-Pb) were determined by ICP-MS, the percentage (%) of global DNA methylation was determined by quantification of 5-methylcytosine using indirect ELISA, and sociodemographic data collected by questionnaire by trained interviewers. The mean age was 37 ± 10 (18–67 years); 18% of participants were smokers, while 32% reported consumption of alcoholic beverages. The B-Pb and P-Pb levels were 20 ± 11 and 0.56 ± 0.64 µg/dl, respectively; % global DNA methylation was 2.8 ± 1.1% (ranging from 1.1 to 6.5%). B-Pb and P-Pb concentrations were significantly correlated. Furthermore, a marked association was noted between Pb biomarkers and DNA global methylation. Taken together, our data demonstrated that Pb exposure induced alterations on DNA global methylation in workers who were exposed to the metal and consequently may result in disturbances in the regulation of gene expression, leading to potentially several health adverse effect outcomes.

DNA methylation profiles of 22 apoptosis-related genes in odontogenic keratocysts before and after marsupialization

Odontogenic keratocysts (OKCs) are cystic lesions of the jaw and tend to recur after treatment. Marsupialization is an effective preliminary treatment for large OKCs. This procedure induces epithelial lining changes in association with reduction of Bcl-2 protein expression, but the underlying mechanisms remain unknown. The purpose of our study was to compare the methylation profile of the apoptosis-related genes of OKCs before and after marsupialization. We assessed the methylation percentages of the promoter region of 22 apoptosis-related genes in 13 OKCs, both marsupialized and nonmarsupialized lesions, by using methylation quantitative polymerase chain reaction array. We validated the expression of genes that showed the greatest differences in methylation percentages between the 2 groups. LTBR and BCLAF1 showed higher DNA methylation percentages in the marsupialized OKCs, but this difference did not affect gene expression (P > .05). The other 20 genes showed similar DNA methylation in both OKC groups. OKCs show a distinct methylation profile after marsupialization, but this is not followed by gene expression alterations.