Phthalates, which are used as plasticizers in plastics, can considerably increase the risk of allergies among children. According to a new study, an increased risk of children developing allergic asthma exists if the mother has been particularly heavily exposed to phthalates during pregnancy and breastfeeding.
2017 Study Abstract
Background
Prenatal and early postnatal exposures to environmental factors are considered responsible for the increasing prevalence of allergic diseases. Although there is some evidence for allergy-promoting effects in children due to exposure to plasticizers like phthalates, findings of previous studies are inconsistent and lack mechanistic information.
Objective
We investigated the effect of maternal phthalate exposure on asthma development in the subsequent generations and their underlying mechanisms including epigenetic alterations.
Methods
Phthalate metabolites were measured within the prospective mother-child cohort LINA and correlated with asthma development in the children. A murine trans-generational asthma model was used to identify involved pathways.
Results
In LINA maternal urinary concentrations of mono-n-butyl phthalate, a metabolite of butyl benzyl phthalate (BBP), were associated with an increased asthma risk in the children. Using a murine trans-generational asthma model, we demonstrate a direct effect of BBP on asthma severity in the offspring with a persistently increased airway inflammation up to the F2 generation. This disease-promoting effect was mediated by a BBP-induced global DNA hypermethylation in CD4 T cells of the offspring as treatment with a DNA demethylating agent alleviated exacerbation of allergic airway inflammation. 13 transcriptionally down-regulated genes linked to promoter or enhancer hypermethylation were identified. Among these, the GATA-3 repressor Zfpm1 emerged as a potential mediator of the enhanced susceptibility for Th2-driven allergic asthma.
Conclusion
These data provide strong evidence that maternal BBP exposure increases the risk for allergic airway inflammation in the offspring by modulating the expression of genes involved in Th2 differentiation via epigenetic alterations.
Sources and Press Releases
- Maternal Phthalate Exposure Promotes Allergic Airway Inflammation over Two Generations Via Epigenetic Modifications, jacionline, DOI: 10.1016/j.jaci.2017.03.017, 1 March 2017.
- Phthalates increase the risk of allergies among children, medicalxpress, May 3, 2017.
- Image credit: UFZ/André Künzelmann – In the course of the LINA mother-child cohort study, UFZ scientists investigated the lifestyle and environmental factors of pregnant women and their influence on the allergy risk of infants.