Frederica Perera, Ph.D.
Columbia University Health Sciences
P50ES09600, P01ES09600, R01ES13163, R01ES014393, R01ES08977
In a proof-of-concept study, NIEHS grantees developed an approach that uses DNA methylation signatures to predict prenatal exposure to environmental contaminants that may harm health.
Using air pollution as a case-study, the researchers sought to identify a biomarker that would distinguish newborns with higher risk from a toxic prenatal exposure to nitrogen dioxide (NO2), polycyclic aromatic hydrocarbons (PAHs), and particulate matter (PM2.5). Specifically, they looked for DNA methylation signatures in umbilical cord blood from two long-term New York City cohorts and analyzed those signatures in relation to modeled exposure to air pollutants during pregnancy.
In a screening step, the researchers identified prenatal exposures that could potentially be predicted by measured changes in DNA methylation and specific DNA regions that could be used to make predictions. Their analysis revealed that alterations to 500 top DNA sites, called CpGs, reliably identified pollutant exposures. The researchers used these sites to build predictive models.
The team ranked and selected the most informative CpG sites. Then they tested how well the top sites predicted exposure to each pollutant and how many CpG sites were needed to make the best prediction. Cord blood DNA methylation reliably predicted high versus low exposure to PM2.5 averaged across the entire pregnancy. The method also predicted exposure to NO2 averaged across the third trimester and the entire pregnancy. It did not work as well for predicting exposure to PAHs.
According to the authors, the simple approach is generalizable to other exposures, which may help identify children at risk of exposure-related developmental disorders to facilitate earlier interventions.
Citation: Wang Y, Perera F, Guo J, Riley KW, Durham T, Ross Z, Ananth CV, Baccarelli A, Wang S, Herbstman JB. 2021. A methodological pipeline to generate an epigenetic marker of prenatal exposure to air pollution indicators. Epigenetics; doi: 10.1080/15592294.2021.1872926. [Online 19 Jan 2021].