Transcriptomics effects of per- and polyfluorinated alkyl substances in differentiated neuronal cells

Per- and polyfluorinated alkyl substances (PFAS) are pervasive environmental contaminants that bioaccumulate in tissues and pose risks to human health. Increasing evidence links PFAS to neurodegenerative and behavioral disorders, yet the underlying mechanisms of their effects on neuronal function remain largely unexplored. In this study, we utilized SH-SY5Y neuroblastoma cells, differentiated into neuronal-like cells, to investigate the impact of six PFAS compounds-- perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorodecanoic acid (PFDA), perfluorodecanesulfonic acid (PFDS), 8:2 fluorotelomer sulfonate (8:2 FTS), and 8:2 fluorotelomer alcohol (8:2 FTOH)--on neuronal health. Following a 30 M exposure for 24 hours, PFAS accumulation ranged from 100-7500 ng/mg of protein. Transcriptomic analysis revealed 721 differentially expressed genes (DEGs) across treatments (padj < 0.05), with 11 DEGs shared among all PFAS exposures, indicating potential biomarkers for neuronal PFAS toxicity. PFOA-treated cells showed downregulation of genes involved in synaptic growth and neural function, while PFOS, PFDS, 8:2 FTS, and 8:2 FTOH exposures resulted in upregulation of genes related to hypoxia response and amino acid metabolism. Lipidomic profiling further demonstrated significant fatty acid upregulation with PFDA, PFDS, and 8:2 FTS, alongside triacylglycerol downregulation with 8:2 FTOH. These findings suggest that the neurotoxic effects of PFAS are structurally dependent, offering insights into the molecular processes that may drive PFAS-induced neuronal dysfunction. SynopsisPer- and poly fluorinated alkyl substances (PFAS) have been shown to bioaccumulate in human tissues and affect health. This study aims to provide insights into the specific biological processes through which PFAS exposure affects neuronal cells.