Stress: a possible link between genetics, epigenetics, and childhood asthma

Association Between Enterovirus Infection and Asthma in Children: A 16-year Nationwide Population-based Cohort Study

BACKGROUND

Both virus-induced asthma and enterovirus (EV) infection are common in children; however, the relationship between EV infection and virus-induced asthma has not been systematically investigated in a cohort study. This nationwide population-based cohort study investigated the association between EV infection and asthma.

METHODS

We used data from the Taiwan National Health Insurance Research Database. The study sample consisted of insured children who were younger than 18 years and had EV infection between 1997 and 2013 and were followed until December 2013. We identified 36,935 children with EV infection and compared them based on 36,935 age-, sex-, urbanization- and income-matched controls to analyze the risk of subsequent asthma. Cox regression analyses were performed and adjusted for sex, age, urbanization, income, preterm labor and small for gestational age, perinatal complications, allergic rhinitis, allergic conjunctivitis, atopic dermatitis and bronchiolitis.

RESULTS

The mean follow-up interval for all patients was 8.59 years (standard deviation = 4.35 years). The mean latency period between initial EV infection and onset of asthma was 2.77 years (standard deviation = 2.43 years). EV infection was significantly associated with a higher incidence of asthma (hazard ratio = 1.65; 95% confidence interval: 1.60-1.71).

CONCLUSIONS

A significant association was observed between EV infection and asthma in children. Health providers should be aware of the higher potential for children with EV to develop asthma in the future.

Review of Environmental Impact on the Epigenetic Regulation of Atopic Diseases

There has been significant increase in the prevalence of atopy over the past decade that cannot be explained by genetic predisposition. Environmental factors including nutrition, the uterine environment, and lifestyle factors are known to play a role in gene expression through epigenetic modifications. In this article, we review the literature on the environmental impact on epigenetic modulation of atopic diseases including asthma, food allergy, eczema, and allergic rhinitis. Recent public release of epigenomic data for hundreds of human tissues provides a powerful resource for further investigation of the molecular basis of atopic diseases.

Parental stress and the onset and course of childhood asthma

The influence of a caregiver’s stress on the development of childhood asthma is an important aspect of the treatment and prevention of illness. Many cross-sectional studies have investigated the association between parenting attitude and/or caregiver’s stress and childhood asthma morbidity, but prospective studies are more advantageous than cross-sectional studies in interpreting a causal relationship from the results. We here present an overview of prospective studies that have reported a relationship between parental stress and the morbidity or course of childhood asthma and discuss the role of parental mental health in its prevention and treatment. Almost all of the studies referred to in this paper show that caregiver (mostly mothers) stress contributed to the onset and to a poor prognosis, while only a few studies have examined the adverse effect of paternal stress on childhood asthma. Their results are inconsistent, and there is insufficient data examining specific stress-related properties that can be targeted in intervention studies. Not only maternal but also paternal influence should be considered in future studies, and it will be important to assess specific stress-related properties that can be the foundation of specific intervention methods.

Advances in pediatric asthma in 2013: coordinating asthma care

Last year's "Advances in pediatric asthma: moving toward asthma prevention" concluded that "We are well on our way to creating a pathway around wellness in asthma care and also to utilize new tools to predict the risk for asthma and take steps to not only prevent asthma exacerbations but also to prevent the early manifestations of the disease and thus prevent its evolution to severe asthma." This year's summary will focus on recent advances in pediatric asthma on prenatal and postnatal factors altering the natural history of asthma, assessment of asthma control, and new insights regarding potential therapeutic targets for altering the course of asthma in children, as indicated in Journal of Allergy and Clinical Immunology publications in 2013 and early 2014. Recent reports continue to shed light on methods to understand factors that influence the course of asthma, methods to assess and communicate levels of control, and new targets for intervention, as well as new immunomodulators. It will now be important to carefully assess risk factors for the development of asthma, as well as the risk for asthma exacerbations, and to improve the way we communicate this information in the health care system. This will allow parents, primary care physicians, specialists, and provider systems to more effectively intervene in altering the course of asthma and to further reduce asthma morbidity and mortality.

Histone modifications of Notch1 promoter affect lung CD4+ T cell differentiation in asthmatic rats

Asthma is an inflammatory disease of the airways, and the current treatment in managing asthma is the control of inflammation. Notch signaling pathway has been linked to T-cell imbalance. The present study aimed to explore the histone modifications of Notch1 promoter in normal and asthmatic lung CD4+ T cells. Chromatin immunoprecipitation analysis showed that the acetylation levels of total H3, H4, site-specific H3K9, H3K14, H3K27, H3K18, H4K16, and the trimethylation levels of H3K4, H3K79 of Notch1 gene promoter were increased significantly in asthmatic lung CD4+ T cells compared to the control group, which correlated with increased P300, PCAF activity and decreased HDAC1, HDAC2 activity. After intervention of garcinol, a potent inhibitor of histone acetyltransferases, in asthmatic lung CD4+ T cells, HAT activity decreased significantly and the increased Notch1 and hes-1 expression was reversed. The total H3ac, H4ac, site-specific H3K9ac, H3K14ac, H3K27ac, H3K18ac, H4K16ac and H3K79me3 levels of Notch1 gene promoter decreased significantly, and the H3K4me3, H3K9me3, H4K20me3 levels had no significant difference. We further investigated the suppressive effects of GAR on asthmatic parameters. Results showed that the levels of IL-4, IL-5 and IL-13 were significantly reduced and a small reverse trend was found in the level of IFN-g after GAR treatment. Furthermore, the expression of NF-κB and AP-1 reduced significantly. These results suggest that asthma is associated with changes in the epigenetic status of Notch1 promoter, including abnormal histone acetylation and methylation, and GAR may have applications in the treatment of asthma.