| Autor: |
Gebreab, Kiflom Y.1 (AUTHOR), Eeza, Muhamed N.H.2,3 (AUTHOR), Bai, Tianyu2,3 (AUTHOR), Zuberi, Zain4 (AUTHOR), Matysik, Jörg3 (AUTHOR), O'Shea, Kevin E.1 (AUTHOR), Alia, A.2,5 (AUTHOR), Berry, John P.1 (AUTHOR) berryj@fiu.edu |
| Abstrakt: |
Owing to environmental health concerns, a number of per- and polyfluoroalkyl substances (PFAS) have been phased-out, and increasingly replaced by various chemical analogs. Most prominent among these replacements are numerous perfluoroether carboxylic acids (PFECA). Toxicity, and environmental health concerns associated with these next-generation PFAS, however, remains largely unstudied. The zebrafish embryo was employed, in the present study, as a toxicological model system to investigate toxicity of a representative sample of PFECA, alongside perfluorooctanoic acid (PFOA) as one of the most widely used, and best studied, of the "legacy" PFAS. In addition, high-resolution magic angle spin (HRMAS) NMR was utilized for metabolic profiling of intact zebrafish embryos in order to characterize metabolic pathways associated with toxicity of PFAS. Acute embryotoxicity (i.e., lethality), along with impaired development, and variable effects on locomotory behavior, were observed for all PFAS in the zebrafish model. Median lethal concentration (LC 50) was significantly correlated with alkyl chain-length, and toxic concentrations were quantitatively similar to those reported previously for PFAS. Metabolic profiling of zebrafish embryos exposed to selected PFAS, specifically including PFOA and two representative PFECA (i.e., GenX and PFO3TDA), enabled elaboration of an integrated model of the metabolic pathways associated with toxicity of these representative PFAS. Alterations of metabolic profiles suggested targeting of hepatocytes (i.e., hepatotoxicity), as well as apparent modulation of neural metabolites, and moreover, were consistent with a previously proposed role of mitochondrial disruption and peroxisome proliferator-activated receptor (PPAR) activation as reflected by dysfunctions of carbohydrate, lipid and amino acid metabolism, and consistent with a previously proposed contribution of PFAS to metabolic syndrome. Taken together, it was generally concluded that toxicity of PFECA is quantitatively and qualitatively similar to PFOA, and these analogs, likewise, represent potential concerns as environmental toxicants. Image 1 • Perfluoroether carboxylic acids (PFECA) are emerging perfluoroalkyl substances (PFAS). • Toxicometabolomics of PFECA and "legacy" PFAS was studied in the zebrafish embryo model. • Toxicity of PFECA was comparable to perfluorooctanoic acid (PFOA) as a legacy PFAS. • High-resolution magic-angle spin NMR enabled metabolic profiling of PFAS-exposed embryos. • Metabolic profiles enabled elaboration of an integrated model of metabolic toxicity of PFAS. Assessment indicates that perfluoroethercarboxylic acids (PFECA) are comparably toxic to perfluorooctanoic acid (PFOA), and may contribute to metabolic syndrome. [ABSTRACT FROM AUTHOR] |
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