Early Stage Exposure of 1H,1h,2h,2h-Perfluorooctanesulfonate-induced Cardiovascular Abnormality in Zebrafish Embryos and Larvae

The novel per- and polyfluoroalkyl substances (PFAS) have attracted global attention due to their persistence, bioaccumulation, and various toxicities. Few studies have focused on the toxicological effects of 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2 FTS), an alternative of perfluorooctanesulfonate (PFOS) detected worldwide. In this study, PFOS was used as a positive control to evaluate the developmental toxicity of 6:2 FTS in zebrafish embryos and larvae. The results of embryo exposure showed that the acute toxicity of 6:2 FTS was lower than that of PFOS. 6:2 FTS could affect the development of zebrafish, including increasing the utilization of yolk sac and the length of the pharyngeal pouch, leading to pericardial edema and inhibiting beating of the heart. Then transgenic zebrafish CZ63 and CZ40 were used to further explore its cardiovascular toxicity. 6:2 FTS could induce vascular hyperplasia, inhibit atrial development, and reduce blood flow velocity in larvae at 72 hours postfertilization. By employing transcriptome analysis and reverse transcription polymerase chain reaction, the involved molecular pathway was finally investigated. Two micromolar 6:2 FTS enhanced the activity of CAT and GSH-Px, involved in calcium signal transduction and myocardial contraction, and affected the MAPK, FoxO, and p53 signaling pathways. Our study can provide scientific insight into the biological safety and health risk of 6:2 FTS.