Assessing effects of air pollution exposure on trophoblast cell mRNA and EV miRNA expression.

SUMMARY Air pollution is a ubiquitous environmental exposure that is consistently linked to adverse developmental trajectories in animal and human studies. However, the definitive mechanisms for these effects are currently unknown, limiting our biological understanding and delaying interventional and therapeutic efforts to protect

children from this widespread exposure. The placenta oversees prenatal development through regulation of fetal growth and its endocrine functions. In the parent R01 study (R01ES032818), we proposed to explore post-transcriptional modifications of RNA, i.e., the epitranscriptome, as potential mediators of black carbon-

related neurotoxicity. In this diversity supplement, we will build on the outlined aims of the parent grant by expanding the exposure to a mixed composition of diesel exhaust pollutants and the placental molecular evaluations of to include overall transcriptome-wide expression changes and content of extracellular vesicles.

We hypothesize that air pollutants alter expression profiles of miRNAs housed within placental cells and shed from placental cells in extracellular vesicles (EVs). To investigate this hypothesis, we propose a series of in vitro studies in the JEG-3 trophoblast cell line. In Aim 1, we will determine the association between diesel

exhaust exposure and transcriptome-wide alterations in placental miRNA expression. In Aim 2, we will determine the association between diesel exhaust exposure and transcriptome-wide alterations in placenta- derived EV miRNA expression. This project will provide novel evidence on the role of the placenta as a

conveyor of developmental toxicity due to prenatal air pollution exposure. Importantly, this supplement will also support training opportunities for an engaged and motivated Master of Public Health graduate student who is interested to cultivate his burgeoning interests in the field of Environmental Health, further ensuring that our

research team includes those traditionally underrepresented in this area of research.