Oral contraceptives modify the effect of GATA3 polymorphisms on the risk of asthma at the age of 18 years via DNA methylation

The role of epigenetics in multi-generational transmission of asthma: An NIAID workshop report-based narrative review

There is mounting evidence that environmental exposures can result in effects on health that can be transmitted across generations, without the need for a direct exposure to the original factor, for example, the effect of grandparental smoking on grandchildren. Hence, an individual's health should be investigated with the knowledge of cross-generational influences. Epigenetic factors are molecular factors or processes that regulate genome activity and may impact cross-generational effects. Epigenetic transgenerational inheritance has been demonstrated in plants and animals, but the presence and extent of this process in humans are currently being investigated. Experimental data in animals support transmission of asthma risk across generations from a single exposure to the deleterious factor and suggest that the nature of this transmission is in part due to changes in DNA methylation, the most studied epigenetic process. The association of father's prepuberty exposure with offspring risk of asthma and lung function deficit may also be mediated by epigenetic processes. Multi-generational birth cohorts are ideal to investigate the presence and impact of transfer of disease susceptibility across generations and underlying mechanisms. However, multi-generational studies require recruitment and assessment of participants over several decades. Investigation of adult multi-generation cohorts is less resource intensive but run the risk of recall bias. Statistical analysis is challenging given varying degrees of longitudinal and hierarchical data but path analyses, structural equation modelling and multilevel modelling can be employed, and directed networks addressing longitudinal effects deserve exploration as an effort to study causal pathways.

Perimenstrual Asthma in Adolescents: A Shared Condition in Pediatric and Gynecological Endocrinology

Asthma is a frequent medical condition in adolescence. The worsening of the most common symptoms perimenstrually is defined as perimenstrual asthma (PMA). The cause of PMA remains unclear, but a role for hormonal milieu is plausible. Data on PMA in adolescents are limited, and its management is not fully established. We aimed to discuss the PMA phenomenon in young females from pathophysiology to preventive strategies, focusing on the relationship with the hormonal pattern. The fluctuation of estrogens at ovulation and before menstruation and the progesterone secretion during the luteal phase and its subsequent withdrawal seem to be the culprits, because the deterioration of asthma is cyclical during the luteal phase and/or during the first days of the menstrual cycle. Conventional asthma therapies are not always effective for PMA. Preventive strategies may include innovative hormonal contraception. Even a possible beneficial effect of other hormonal treatments, including estrogens, progestogens, and androgens, as well as leukotriene receptor antagonists and explorative approach using microbial-directed therapy, is considered. The underlying mechanisms, through which sex-hormone fluctuations influence asthma symptoms, represent a challenge in the clinical management of such a distressing condition. Further studies focused on young females are mandatory to promote adolescent health.

DNA Methylation of Cannabinoid Receptor Interacting Protein 1 Promotes Pathogenesis of Intrahepatic Cholangiocarcinoma Through Suppressing Parkin-Dependent Pyruvate Kinase M2 Ubiquitination

BACKGROUND AND AIMS

Methylation landscape is important for maintaining the silence of cannabinoid receptor-interacting protein 1 (CNRIP1) in some tumors. However, the role of CNRIP1 in intrahepatic cholangiocarcinoma (ICC) remains poorly defined.

APPROACH AND RESULTS

In our study, we showed that CNRIP1 was down-regulated in ICC tissues, and low expression of CNRIP1 was significantly associated with poor prognosis of patients with ICC in 3-year overall survival and tumor-free survival. Investigating the genomic DNA methylation profile, we disclosed a CpG island site named CNRIP1 MS-2 (CNRIP1 methylation site-2) that contributes to the down-regulation of CNRIP1. In addition, the methylation level of CNRIP1 MS-2 was correlated to the pathological grade, metastasis, and tumor-node-metastasis classification in ICC. Notably, we observed that CNRIP1 suppressed tumor cell migration, invasion, and proliferation by inhibiting the activity of pyruvate kinase M2 (PKM2). Sustained overexpression of CNRIP1 suppressed the in vivo tumor growth in a mouse xenograft model. It was also found that CNRIP1 overexpression activated Parkin (an E3 ubiquitin ligase), which resulted in the protein degradation of PKM2 in ICC cells.

CONCLUSIONS

We identified that CNRIP1 acted as a putative tumor suppressor in ICC, which suggested that CNRIP1 could be a candidate biomarker for predicting tumor recurrence in patients with ICC. Furthermore, these findings highlight a potential therapeutic approach in targeting the CNRIP1/Parkin/PKM2 pathway for the treatment of ICC.

A review of epigenetic changes in asthma: methylation and acetylation

Several studies show that childhood and adulthood asthma and its symptoms can be modulated through epigenetic modifications. Epigenetic changes are inheritable modifications that can modify the gene expression without changing the DNA sequence. The most common epigenetic alternations consist of DNA methylation and histone modifications. How these changes lead to asthmatic phenotype or promote the asthma features, in particular by immune pathways regulation, is an understudied topic. Since external effects, like exposure to tobacco smoke, air pollution, and drugs, influence both asthma development and the epigenome, elucidating the role of epigenetic changes in asthma is of great importance. This review presents available evidence on the epigenetic process that drives asthma genes and pathways, with a particular focus on DNA methylation, histone methylation, and acetylation. We gathered and assessed studies conducted in this field over the past two decades. Our study examined asthma in different aspects and also shed light on the limitations and the important factors involved in the outcomes of the studies. To date, most of the studies in this area have been carried out on DNA methylation. Therefore, the need for diagnostic and therapeutic applications through this molecular process calls for more research on the histone modifications in this disease.

Interweaving Between Genetic and Epigenetic Studies on Childhood Asthma

The cause and underlying mechanisms that contribute to asthma pathogenesis are not well known. Both genome- and epigenome-wide association studies have identified genes associated with asthma risk. It is unknown to what extent genes identified in these two types of studies overlap. Based on existing literature and the DisGeNET database, we extracted overlapping genes identified in genetic and epigenetic studies of childhood asthma. Through analyses of variance, we assessed whether DNA methylation (DNAm) at 5′-C-phosphate-G-3′ (CpGs) on the overlapping genes was associated with neighboring single-nucleotide polymorphisms (SNPs) within 1M base pairs (bps) and with low linkage disequilibrium (r² < 0.2) in the childhood asthma-related genes. In total, 285 genes from genetic studies and 226 genes from epigenetic studies were shown to be associated with asthma risk, of which six overlap. Of the six genes, 79 CpGs and 8229 unique neighboring SNPs (1M bps) were included in methylation quantitative loci (methQTL) assessment analyses. We tested the association of DNAm at each of the 79 CpG sites with its neighboring SNPs. After adjusting for multiple testing by controlling the false discovery rate to 0.05 when testing methQTL for each CpG site, we found statistically significant associations in three genes with their neighboring SNPs and identified 34 unique methQTLs. The rather limited overlap in genes between genetic and epigenetic studies on asthma and the absence of methQTL in some of the overlapping genes highlight a need to jointly, rather than independently, examine genetic and epigenetic effects on asthma risk to improve our understanding of the underlying mechanisms of asthma.

Changes of DNA methylation are associated with changes in lung function during adolescence

BACKGROUND

Adolescence is a significant period for the gender-dependent development of lung function. Prior studies have shown that DNA methylation (DNA-M) is associated with lung function and DNA-M at some cytosine-phosphate-guanine dinucleotide sites (CpGs) changes over time. This study examined whether changes of DNA-M at lung-function-related CpGs are associated with changes in lung function during adolescence for each gender, and if so, the biological significance of the detected CpGs.

METHODS

Genome-scale DNA-M was measured in peripheral blood samples at ages 10 (n = 330) and 18 years (n = 476) from the Isle of Wight (IOW) birth cohort in United Kingdom, using Illumina Infinium arrays (450 K and EPIC). Spirometry was conducted at both ages. A training and testing method was used to screen 402,714 CpGs for their potential associations with lung function. Linear regressions were applied to assess the association of changes in lung function with changes of DNA-M at those CpGs potentially related to lung function. Adolescence-related and personal and family-related confounders were included in the model. The analyses were stratified by gender. Multiple testing was adjusted by controlling false discovery rate of 0.05. Findings were further examined in two independent birth cohorts, the Avon Longitudinal Study of Children and Parents (ALSPAC) and the Children, Allergy, Milieu, Stockholm, Epidemiology (BAMSE) cohort. Pathway analyses were performed on genes to which the identified CpGs were mapped.

RESULTS

For females, 42 CpGs showed statistically significant associations with change in FEV1/FVC, but none for change in FEV1 or FVC. No CpGs were identified for males. In replication analyses, 16 and 21 of the 42 CpGs showed the same direction of associations among the females in the ALSPAC and BAMSE cohorts, respectively, with 11 CpGs overlapping across all the three cohorts. Through pathway analyses, significant biological processes were identified that have previously been related to lung function development.

CONCLUSIONS

The detected 11 CpGs in all three cohorts have the potential to serve as the candidate epigenetic markers for changes in lung function during adolescence in females.

Changes in DNA methylation from pre- to post-adolescence are associated with pubertal exposures

BACKGROUND

Adolescence is a period characterized by major biological development, which may be associated with changes in DNA methylation (DNA-M). However, it is unknown to what extent DNA-M varies from pre- to post-adolescence, whether the pattern of changes is different between females and males, and how adolescence-related factors are associated with changes in DNA-M.

METHODS

Genome-scale DNA-M at ages 10 and 18 years in whole blood of 325 subjects (n = 140 females) in the Isle of Wight (IOW) birth cohort was analyzed using Illumina Infinium arrays (450K and EPIC). Linear mixed models were used to examine DNA-M changes between pre- and post-adolescence and whether the changes were gender-specific. Adolescence-related factors and environmental exposure factors were assessed on their association with DNA-M changes. Replication of findings was attempted in the comparable Avon Longitudinal Study of Parents and Children (ALSPAC) cohort.

RESULTS

In the IOW cohort, after controlling for technical variation and cell compositions at both pre- and post-adolescence, 15,532 cytosine-phosphate-guanine (CpG) sites (of 400,825 CpGs, 3.88%) showed statistically significant DNA-M changes from pre-adolescence to post-adolescence invariant to gender (false discovery rate (FDR) = 0.05). Of these 15,532 CpGs, 10,212 CpGs (66%) were replicated in the ALSPAC cohort. Pathway analysis using Ingenuity Pathway Analysis (IPA) identified significant biological pathways related to growth and development of the reproductive system, emphasizing the importance of this period of transition on epigenetic state of genes. In addition, in IOW, we identified 1179 CpGs with gender-specific DNA-M changes. In the IOW cohort, body mass index (BMI) at age 10 years, age of growth spurt, nonsteroidal drugs use, and current smoking status showed statistically significant associations with DNA-M changes at 15 CpGs on 14 genes such as the AHRR gene. For BMI at age 10 years, the association was gender-specific. Findings on current smoking status were replicated in the ALSPAC cohort.

CONCLUSION

Adolescent transition is associated with changes in DNA-M at more than 15K CpGs. Identified pathways emphasize the importance of this period of transition on epigenetic state of genes relevant to cell growth and immune system development.

DNA methylation and allergic sensitizations: A genome-scale longitudinal study during adolescence

BACKGROUND

The presence of allergic sensitization has a major influence on the development and course of common childhood conditions such as asthma and rhinitis. The etiology of allergic sensitization is poorly understood, and its underlying biological mechanisms are not well established. Several studies showed that DNA methylation (DNAm) at some CpGs is associated with allergic sensitization. However, no studies have focused on the critical adolescence period.

METHODS

We assessed the association of pre- and postadolescence genome-wide DNAm with allergic sensitization against indoor, outdoor and food allergens, using linear mixed models. We hypothesized that DNAm is associated with sensitization in general, and with poly-sensitization status, and these associations are age- and gender-specific. We tested these hypotheses in the IoW cohort (n = 376) and examined the findings in the BAMSE cohort (n = 267).

RESULTS

Via linear mixed models, we identified 35 CpGs in IoW associated with allergic sensitization (at false discovery rate of 0.05), of which 33 were available in BAMSE and replicated with respect to the direction of associations with allergic sensitization. At the 35 CpGs except for cg19210306 on C13orf27, a reduction in methylation among atopic subjects was observed, most notably for cg21220721 and cg11699125 (ACOT7). DNAm at cg10159529 was strongly correlated with expression of IL5RA in peripheral blood (P-value = 6.76 × 10^-20 ). Three CpGs (cg14121142, cg23842695, and cg26496795) were identified in IoW with age-specific association between DNAm and allergic sensitization.

CONCLUSION

In adolescence, the status of allergic sensitization was associated with DNAm differentiation and at some CpGs the association is likely to be age-specific.

A review on the pathophysiology of asthma remission

Asthma is a chronic respiratory condition, which is highly prevalent worldwide. Although no cure is currently available, it is well recognized that some asthma patients can spontaneously enter remission of the disease later in life. Asthma remission is characterized by absence of symptoms and lack of asthma-medication use. Subjects in asthma remission can be divided into two groups: those in clinical remission and those in complete remission. In clinical asthma remission, subjects still have a degree of lung functional impairment or bronchial hyperresponsiveness, while in complete asthma remission, these features are no longer present. Over longer periods, the latter group is less likely to relapse. This remission group is of great scientific interest due to the higher potential to find biomarkers or biological pathways that elicit or are associated with asthma remission. Despite the fact that the definition of asthma remission varies between studies, some factors are reproducibly observed to be associated with remitted asthma. Among these are lower levels of inflammatory markers, which are lowest in complete remission. Additionally, in both groups some degree of airway remodeling is present. Still, the pathological disease state of asthma remission has been poorly investigated. Future research should focus on at least two aspects: further characterisation of the small airways and airway walls in order to determine histologically true remission, and more thorough biological pathway analyses to explore triggers that elicit this phenomenon. Ultimately, this will result in pharmacological targets that provide the potential to steer the course of asthma towards remission.

GLI2 promoter hypermethylation in saliva of children with a respiratory allergy

Background

The prevalence of respiratory allergy in children is increasing. Epigenetic DNA methylation changes are plausible underlying molecular mechanisms.

Results

Saliva samples collected in substudies of two longitudinal birth cohorts in Belgium (FLEHS1 & FLEHS2) were used to discover and confirm DNA methylation signatures that can differentiate individuals with respiratory allergy from healthy subjects. Genome-wide analysis with Illumina Methylation 450K BeadChips revealed 23 differentially methylated gene regions (DMRs) in saliva from 11y old allergic children (N=26) vs. controls (N=20) in FLEHS1. A subset of 7 DMRs was selected for confirmation by iPLEX MassArray analysis. First, iPLEX analysis was performed in the same 46 FLEHS1 samples for analytical confirmation of the findings obtained during the discovery phase. iPLEX results correlated significantly with the 450K array data (P <0.0001) and confirmed 4 out of the 7 DMRs. Aiming for additional biological confirmation, the 7 DMRs were analyzed using iPLEX in a substudy of an independent birth cohort (FLEHS2; N=19 cases vs. 20 controls, aged 5 years). One DMR in the GLI2 promoter region showed a consistent statistically significant hypermethylation in individuals with respiratory allergy across the two birth cohorts and technologies. In addition to its involvement in TGF-β signaling and T-helper differentiation, GLI2 has a regulating role in lung development.

Conclusion

GLI2 is considered an interesting candidate DNA methylation marker for respiratory allergy.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0484-1) contains supplementary material, which is available to authorized users.

Imbalanced Expression of Th2 and Treg Cell-related Parameters in Peripheral Blood Mononuclear Cells in Patients with Allergic Asthma

BACKGROUND

The imbalance between Th2 and Treg cells plays fundamental role in the pathogenesis of allergic asthma. The current study aimed at assessing the expression of some Th2 and Treg cell-related parameters in patients with allergic asthma.

MATERIAL AND METHODS

The serum and peripheral blood mononuclear cell (PBMC) samples were collected from 30 patients with asthma and 36 healthy subjects. The serum levels of transforming growth factor (TGF)-β, interleukin (IL)-4, as well as the expression levels of GATA3 and FOXP3 genes in PBMCs were determined by the enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR), respectively. The PBMCs were cultured for 48 hours with/without phytohemagglutinin (PHA) stimulation. The TGF-β and IL-4 levels in supernatants were also determined.

RESULTS

The serum levels of IL-4, the expression level of GATA3, and GATA3/FOXP3 ratio in patients with asthma were significantly higher than healthy subjects (P <0.002, P <0.001, and P <0.004, respectively). The FOXP3 expression did no differ between the two groups. The serum level of TGF-β as well as its secretion profile in non-stimulated and stimulated PBMCs isolated from patients with asthma were significantly higher than those of the controls (P <0.03, P <0.001, and P <0.001, respectively). The serum TGF-β levels in severe asthma were significantly higher than moderate asthma; whereas the TGF-β secretion by PHA-stimulated PBMCs isolated from moderate asthma was higher than that of severe pattern of the disease (P <0.001 and P <0.05, respectively). The GTAT3/FOXP3 expression ratio in moderate asthma was significantly higher than severe form (P <0.04).

CONCLUSION

The results confirmed a Th2 cell-biased pattern and possible contribution of TGF-β in allergic asthma. TGF-β may have different expression patterns in moderate and severe asthma and the two forms of the disease may have differences in some main immunological parameters.

Multigenerational cohorts in patients with asthma and allergy

Recent observations that disease risk can be transmitted across generations without the need for direct exposure of the child to the index environmental insult has sparked interest in transgenerational inheritance. Epigenetics describes processes that modify gene expression without a change in the nucleotide sequence. Epigenetic processes can be induced in response to environmental exposures, can influence disease risk, and might explain these multigenerational effects. In experimental models a number of epigenetic mechanisms have been identified that could mediate vertical transmission of epigenetic inheritance. However, relevance of these findings to human disease is not yet clear. An alternative model is one in which transgenerational inheritance of disease risk requires the presence of exposure-related diseases in the mother during pregnancy (termed induced epigenetic transmission model). A number of cross-sectional studies have investigated multigenerational effects in allergy and asthma. However, given the early-life origins of asthma and allergy, birth cohort studies are ideal to investigate the effect of genetic predisposition, epigenetics, and environmental exposures, avoiding pitfalls, such as recall bias and confounding by ongoing exposures, disease, and treatment. The well-characterized 3 generations of the Isle of Wight cohort include 2 consecutive birth cohorts, providing longitudinal data that can be studied for epigenetic transfer of information, such as the effect of grand parental smoking or exposure to other toxic compounds. Further large multigenerational birth cohorts are needed to establish the clinical relevance of this phenomenon and differentiate between vertical and induced transmission models, which might influence future preventive strategies.

Epigenome-wide association studies for breast cancer risk and risk factors

There have been six epigenome-wide association studies (EWAS) for breast cancer risk using blood DNA from prospective cohorts published thus far, and the only consistent finding is a global loss of methylation observed in breast cancer cases compared with controls, with no individual CpG sites passing validation across studies. In contrast, a more successful approach has been the identification of EWAS signatures of cancer risk factors such as smoking, body mass index, age and alcohol use with numerous validated CpG sites. These signatures may be used as a molecular test to quantify cancer risk associated with these factors. It is clear from the larger EWAS of risk exposures that similar-sized large collaborative studies may be needed to robustly identify DNA methylation signatures of breast cancer risk.

Neonatal Immune State Is Influenced by Maternal Allergic Rhinitis and Associated With Regulatory T cells

Purpose

Maternal influences contribute to the origin of allergic diseases, but the mechanisms are not clear. The current literature prompted the role of epigenetics in the development of allergic diseases. We sought to investigate the roles of regulatory T (Treg) cells and Forkhead box p3 (Foxp3) DNA methylation in the process of maternal transmission of allergic rhinitis (AR) susceptibility.

Methods

BALB/c female mice (AR mother) were sensitized by intraperitoneal injection of Dermatophagoides pteronyssinus (Der p) 1 on day 1 and 7. Then they mated with normal male mice on day 8. From day 21 to 28, the female mice were intranasal challenged with Der p 1 continuously. The normal controls were given with normal saline in the same way. On postnatal day 3, Female mice and their offspring were sacrificed to detect their histopathology in nasal mucosae, cytokines in sera of mother and spleen homogenates of offspring, Treg cells count, Foxp3 mRNA expressions, and Foxp3 DNA methylation levels in spleens.

Results

Compared with the normal controls, neonatal offspring of Der p 1-stimulated female mice (AR offspring) showed the elevation of interleukin (IL)-4 (P<0.01) and IL-17 (P<0.01), the submission of IL-10 (P<0.01) in spleen homogenates. Further, Treg cells count in AR offspring decreased remarkably compared with the normal offspring (P<0.01). Though the difference of Foxp3 DNA methylation level between AR offspring and normal control offspring was not obvious, correlation analysis demonstrated that there was significantly positive correlation between Foxp3 DNA methylation level of mother and that of offspring (r=0.803, P<0.01).

Conclusions

Under the influence of Maternal AR, their neonatal offspring develop into T-helper type 2 (Th2) dominant immune state, which is closely associated with the recession of Treg cells. Foxp3 DNA methylation may be a mechanism responsible for that maternal effect but still need more studies to ensure.

Association between asthma and female sex hormones

CONTEXT AND OBJECTIVE:

The relationship between sex hormones and asthma has been evaluated in several studies. The aim of this review article was to investigate the association between asthma and female sex hormones, under different conditions (premenstrual asthma, use of oral contraceptives, menopause, hormone replacement therapy and pregnancy).

DESIGN AND SETTING:

Narrative review of the medical literature, Universidade Federal do Tocantins (UFT) and Universidade Federal de São Paulo (Unifesp).

METHODS:

We searched the CAPES journal portal, a Brazilian platform that provides access to articles in the MEDLINE, PubMed, SciELO, and LILACS databases. The following keywords were used based on Medical Subject Headings: asthma, sex hormones, women and use of oral contraceptives.

RESULTS:

The associations between sex hormones and asthma remain obscure. In adults, asthma is more common in women than in men. In addition, mortality due to asthma is significantly higher among females. The immune system is influenced by sex hormones: either because progesterone stimulates progesterone-induced blocking factor and Th2 cytokines or because contraceptives derived from progesterone and estrogen stimulate the transcription factor GATA-3.

CONCLUSIONS:

The associations between asthma and female sex hormones remain obscure. We speculate that estrogen fluctuations are responsible for asthma exacerbations that occur in women. Because of the anti-inflammatory action of estrogen, it decreases TNF-α production, interferon-γ expression and NK cell activity. We suggest that further studies that highlight the underlying physiopathological mechanisms contributing towards these interactions should be conducted.

Association of season of birth with DNA methylation and allergic disease

BACKGROUND

Season of birth influences allergy risk; however, the biological mechanisms underlying this observation are unclear. The environment affects DNA methylation, with potentially long-lasting effects on gene expression and disease. This study examined whether DNA methylation could underlie the association between season of birth and allergy.

METHODS

In a subset of 18-year-old participants from the Isle of Wight (IoW) birth cohort (n = 367), the risks of birth season on allergic outcomes were estimated. Whole blood epigenome-wide DNA methylation was measured, and season-associated CpGs detected using a training-and-testing-based technique. Validation method examined the 8-year-old Prevention and Incidence of Asthma and Mite Allergy (PIAMA) cohort. The relationships between DNA methylation, season of birth and allergy were examined. CpGs were analysed in IoW third-generation cohort newborns.

RESULTS

Autumn birth increased risk of eczema, relative to spring birth. Methylation at 92 CpGs showed association with season of birth in the epigenome-wide association study. In validation, significantly more CpGs had the same directionality than expected by chance, and four were statistically significant. Season-associated methylation was enriched among networks relating to development, the cell cycle and apoptosis. Twenty CpGs were nominally associated with allergic outcomes. Two CpGs were marginally on the causal pathway to allergy. Season-associated methylation was largely absent in newborns, suggesting it arises post-natally.

CONCLUSIONS

This study demonstrates that DNA methylation in adulthood is associated with season of birth, supporting the hypothesis that DNA methylation could mechanistically underlie the effect of season of birth on allergy, although other mechanisms are also likely to be involved.

Preconceptional exposure to oral contraceptive pills and the risk of wheeze, asthma and rhinitis in children

BACKGROUND

The prevalence of maternal oral contraceptive pills (OCP) use and that of childhood asthma are high in western countries. The aim of this study is to examine the association of OCP use with childhood wheeze and allergic diseases in Japan.

METHODS

Relevant data were extracted from a hospital based birth cohort study named as Tokyo-Children's Health, Illness and Development Study (T-CHILD) of which questionnaire conducted during pregnancy included maternal history and duration of OCP use. To identify wheeze and allergic diseases in the children, the questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC) was used. Logistic regression models were applied to estimate those association and adjustments were made for maternal history of allergy, maternal education level, maternal age at pregnancy, maternal BMI, maternal smoking during pregnancy, mode of delivery, gestational age at delivery, daycare attendance, number of previous live births, and gender of child.

RESULTS

OCP use was associated with ever wheeze (adjusted odds ratio [aOR], 1.62; 95% confidence interval [CI], 1.10-2.40), current wheeze (aOR, 1.59; 95% CI, 1.01-2.50), ever asthma (aOR, 1.65; 95% CI, 1.02-2.65), and ever rhinitis (aOR, 1.90; 95% CI, 1.30-2.80). Compared with no prior OCP use, using OCP for more than three months statistically increased the odds of ever wheeze (P = 0.012), current wheeze (P = 0.035), and ever rhinitis (P = 0.002).

CONCLUSIONS

Our findings suggest that maternal OCP use has a role in the development of wheeze, asthma and rhinitis in children. Extended use of OCP is likely to increase the risk of wheeze and rhinitis.

Epigenetics of Aging

The best-known phenomenon exemplifying epigenetic drift (the alteration of epigenetic patterns during aging) is the gradual decrease of global DNA methylation. Aging cells, different tissue types, as well as a variety of human diseases possess their own distinct DNA methylation profiles, although the functional impact of these is not always clear. DNA methylation appears to be a dynamic tool of transcriptional regulation, with an extra layer of complexity due to the recent discovery of the conversion of 5-methylcytosine into 5-hydroxymethylcytosine. This age-related DNA demethylation is associated with changes in histone modification patterns and, furthermore, we now know that ncRNAs have evolved in eukaryotes as epigenetic regulators of gene expression. In this review, we will discuss current knowledge on how all these epigenetic phenomena are implicated in human aging, and their links with external, internal and stochastic factors which can affect human age-related diseases onset.

The GATA3 gene is involved in leprosy susceptibility in Brazilian patients

Leprosy outcome is a complex trait and the host-pathogen-environment interaction defines the emergence of the disease. Host genetic risk factors have been successfully associated to leprosy. The 10p13 chromosomal region was linked to leprosy in familial studies and GATA3 gene is a strong candidate to be part of this association. Here, we tested tag single nucleotide polymorphisms at GATA3 in two case-control samples from Brazil comprising a total of 1633 individuals using stepwise strategy. The A allele of rs10905284 marker was associated with leprosy resistance. Then, a functional analysis was conducted and showed that individuals carrying AA genotype express higher levels of GATA-3 protein in lymphocytes. So, we confirmed that the rs10905284 is a locus associated to leprosy and influences the levels of this transcription factor in the Brazilian population.

Unified variable selection in semi-parametric models

We propose a Bayesian variable selection method in semi-parametric models with applications to genetic and epigenetic data (e.g., single nucleotide polymorphisms and DNA methylation, respectively). The data are individually standardized to reduce heterogeneity and facilitate simultaneous selection of categorical (single nucleotide polymorphisms) and continuous (DNA methylation) variables. The Gaussian reproducing kernel is applied to the transformed data to evaluate joint effect of the variables, which may include complex interactions between, e.g., single nucleotide polymorphisms and DNA methylation. Indicator variables are introduced to the model for the purpose of variable selection. The method is demonstrated and evaluated using simulations under different scenarios. We apply the method to identify informative DNA methylation sites and single nucleotide polymorphisms in a set of genes based on their joint effect on allergic sensitization. The selected single nucleotide polymorphisms and methylation sites have the potential to serve as early markers for allergy prediction, and consequently benefit medical and clinical research to prevent allergy before its manifestation.