Exposure to PFOS, PFBS, PFOA and PFBA impairs cell cycle progression in bovine brain (Bos taurus) endothelial cells

Abstract

Perfluoroalkylated substances (PFAS) are the large class of synthetic chemicals that persist in the environment and bioaccumulate in different tissues including the brain, inducing blood brain barrier (BBB) disruption. In this study, we assessed cytotoxicity of PFAS in a bovine brain endothelial cell line by exposing the cells to increasing concentrations (0.01, 0.1, 1, 10, and 100 μM) of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorobutane sulfonic acid (PFBS), perfluorobutanoic acid (PFBA) and perfluoro ([5-methoxy-1,3-dioxolan-4-yl]oxy) acetic acid (C6O4). Cell viability, cell cycle profiling and the apoptotic potential were then analyzed. Cells were categorized by grouping nuclei into G0 + G1, Synthesis (S) and Mitotic phases (M), nuclei showing characteristics of senescence and nuclear fragments. By combining high throughput screening with cell nuclei counting for group, we determined the relationship between the dose-response effect of PFAS and their proliferative potential. Our results showed that PFOS decreased the number of cells in S and M phase. PFBS reduced the number of cells in M phase, decreased the senescence phenotype and increased the number of fragment nuclei. PFOA enhanced the number of cells nuclei in S and M phase. The PFBA enhanced the number of nuclei in G0 + G1, S and M phase. C6O4 did not show significant variation under any of the experimental conditions tested. We did not find significant changes in terms of cell viability assay. This bovine endothelial cell line provides an alternative model for studying the mechanisms involved in the decrease of BBB integrity due to PFAS accumulation in a large mammal with large brain.

Keywords: Bos taurus; Cytotoxicity; Endothelial cells; High throughput screening; PFAS.