Identifying environmental chemicals impacting neurodevelopment using a random mixture-based screening approach

Environmental exposures can impact brain development and contribute to neurodevelopmental disorder risk. In this study, we leveraged insights from in vitro high-throughput screening studies that examined the developmental toxicity of environmental chemicals to select 47 chemicals for in vivo testing as complex random mixtures in pregnant female mice. Our objectives were to identify mixtures that impact key neurodevelopmental endpoints-embryonic body, brain, and placenta weight-and subsequently to use mass spectrometry to ascertain which chemicals from each active mixture entered the developing brain following gestational exposure. We identified 3 chemicals that entered the embryonic brain and reduced embryonic brain weight: Perfluorooctanoic acid (PFOA), fenpyroximate, and 4-tert-octylphenol. Given its effect on embryonic brain weight and its widespread presence in environmental samples, we selected PFOA for further study using single-nuclei RNA sequencing. We found that PFOA altered neural progenitor cell proliferation and neuronal differentiation in the developing mouse cerebral cortex. Furthermore, we found that gestational exposure to PFOA disrupted neurodevelopment by altering the cell cycle in neural progenitor cells of males and females. In conclusion, we identified environmental chemicals that impact neurodevelopmental processes in vivo and found that single-nuclei RNA sequencing can provide new insights into the cellular mechanisms of neurotoxicity.