In vitro screening of understudied PFAS with a focus on lipid metabolism disruption.

ABSTRACT

Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals used in many industrial applications. Exposure to PFAS is associated with several health risks, including a decrease in infant birth weight, hepatoxicity, disruption of lipid metabolism, and decreased immune response. We used the in vitro cell models to screen six less studied PFAS [perfluorooctane sulfonamide (PFOSA), perfluoropentanoic acid (PFPeA), perfluoropropionic acid (PFPrA), 62 fluorotelomer alcohol (62 FTOH), 62 fluorotelomer sulfonic acid (62 FTSA), and 82 fluorotelomer sulfonic acid (82 FTSA)] for their capacity to activate nuclear receptors and to cause differential expression of genes involved in lipid metabolism. Cytotoxicity assays were run in parallel to exclude that observed differential gene expression was due to cytotoxicity. Based on the cytotoxicity assays and gene expression studies, PFOSA was shown to be more potent than other tested PFAS. PFOSA decreased the gene expression of crucial genes involved in bile acid synthesis and detoxification, cholesterol synthesis, bile acid and cholesterol transport, and lipid metabolism regulation. Except for 62 FTOH and 82 FTSA, all tested PFAS downregulated PPARA gene expression. The reporter gene assay also showed that 82 FTSA transactivated the farnesoid X receptor (FXR). Based on this study, PFOSA, 62 FTSA, and 82 FTSA were prioritized for further studies to confirm and understand their possible effects on hepatic lipid metabolism.