Differential toxicity of perfluorooctane sulfonate (PFOS) in wild-type and Oatp1d1 mutant zebrafish larvae

Perfluorooctane sulfonate (PFOS) is a persistent and bioaccumulative member of the per- and polyfluoroalkyl substances (PFAS) family widely used in various industrial applications and consumer products. In this study we present a comprehensive analysis of the effects of PFOS exposure on zebrafish embryos with respect to possible role of the organic anion transporting polypeptide 1d1 (Oatp1d1) membrane transporter, focusing on the differential responses between wild-type (WT) and Oatp1d1 mutant embryos. Significant differences in mortality rates were observed, with LC₅₀ values of 23.57 μM for WT and 16.71 μM for oatp1d1 mutants, indicating a higher susceptibility of the mutants to PFOS toxicity. Developmental abnormalities, particularly in the swim bladder, were more pronounced in mutant embryos. In addition, gene expression analysis showed changes in expression of genes involved in biotransformation processes, including members of the cytochrome P450 and glutathione S-transferase families. In summary, results of this study emphasize the complexity of PFOS-induced developmental toxicity mechanisms, implying important protective role of the Oatp1d1 transporter possibly related to detoxification processes or regulation of bioavailability. The findings improve our understanding of the toxicokinetic and toxicodynamic mechanisms of PFOS, emphasizing potential need for additional regulatory measures to address PFOS contamination and protect both aquatic life and human populations.