Chronic perfluorooctanesulfonic acid exposure disrupts lipid metabolism in zebrafish

Perfluorooctanesulfonic acid (PFOS), a ubiquitous contaminant, has been used in various industrial applications. Currently few studies have documented the effects of chronic PFOS exposure on lipid metabolism, especially in aquatic organisms. The present study defined the effects of chronic exposure to low level of PFOS on lipid metabolism in F0 adult zebrafish and F1 offspring. Our findings revealed a severe fatty degeneration in the liver of F0 males treated with 0.5 μM PFOS and significant ultrastructure changes associated with substance transport or metabolism in liver and intestines (abnormal mitochondria and endoplasmic reticulum, disordered arrangement of inner microvilli within intracellular canaliculus). To address the potential trans-generational effects of PFOS exposure, the early gene expression related to lipid metabolism was measured by real-time quantitative polymerase chain reaction in F1 derived from chronically exposed parental fish. The results indicated that lepa (leptin α), kiss1 (kisspeptins), xdh (xanthine dehydrogenases), and insr (insulin receptor) were significantly upregulated in F1 while dgat1b (diacylglycerol O-acyltransferase), hb9 (motor neuron/pancreas homeobox), and Apoa1 (apolipoprotein A-I) were downregulated. These findings provided evidence that PFOS chronic exposure adversely impacts lipid metabolism in both F0 and F1 and demonstrated the validity of using zebrafish as an alternative model for PFOS chronic toxicity screening.