Single-nucleus RNA-seq and ATAC-seq indicate that in utero Ecig exposure influences neuronal development in rodent offspring

Emerging evidence indicates maternal electronic cigarette (Ecig) exposure during gestation can cause adverse effects on behavior and brain development. Rodent models show an increase in anxiety like behavior and short-term memory deficits when exposed to Ecig aerosol in utero. Neurons are vital to maintaining brain homeostasis and behavior. We used the 10X Genomics platform for single-nucleus (sn)-RNA sequencing and snATAC sequencing to assess differential gene expression and differences in chromatin openness. Pregnant Sprague Dawley rats were exposed from gestational day 2 to 21 to the base Ecig liquid with 50:50 (v:v) ratio of vegetable glycerin and propylene glycol with no nicotine and no flavorings aerosolized at 5 watts or 30 watts power setting. Differing device power was used to create a cloud density corresponding to low (5w = 163 mg/m 3 ) and high (30w = 917 mg/m 3 ) exposure dose groups. After birth, offspring were aged to 6-months and then brain samples from the cerebral cortex were collected and analyzed. Seven cell types were detected (i.e. inhibitory neurons, excitatory neurons, oligodendrocytes, oligodendrocyte progenitor cells, vasculature associated cells, astrocytes, and microglia) using established cell-specific marker genes. We hypothesized that there would be differences in chromatin accessibility and transcription of excitatory and inhibitory neurons corresponding to behavioral changes in adult (6-month) rat offspring with gestational Ecig exposure compared to controls (i.e. offspring from dams exposed only to ambient air). The threshold |log2 fold change|>1.00 (p-value <0.01) was applied to the differentially expressed genes. Excitatory neuron cluster exhibited 11 upregulated and 154 downregulated genes in the 5 watt exposure group and 977 downregulated genes in the 30 watt group. The inhibitory neuron cluster showed 80 upregulated and 202 downregulated genes in the 5 watt exposure group and 6 upregulated and 949 downregulated genes in the 30 watt group. Gene ontology enrichment analysis (ShinyGo 0.80) revealed there were only a few pathways differentially regulated with Ecigs compared to Air in excitatory neurons. In contrast, changes in gene expression corresponding to multiple neurodegenerative conditions (including Alzheimer's, Prion, and Parkinson disease) were found with inhibitory neurons collected from the 30W exposure group. These data suggest gestational exposure from maternal vaping during pregnancy affects neuronal development in a way which causes long-lasting effects that may increase risk for several neurodegenerative conditions. AHA CSA 20CSA35320107 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.