Perfluoroethylcyclohexane sulfonate (PFECHS) is an emerging per- and polyfluoroalkyl substance used to replace perfluorooctane sulfonate (PFOS), mainly in aircraft hydraulic fluids. However, previous research indicates the potential neurotoxicity of this replacement chemical. In this study, marine medaka (Oryzias melastigma) was exposed to environmentally relevant concentrations of PFECHS (concentrations: 0, 0.08, 0.26, and 0.91 μg/L) from the embryonic stage for 90 days. After exposure, the brain and eyes of the medaka were collected to investigate the bioconcentration potential of PFECHS stereoisomers and their effects on the nervous systems. The determined bioconcentration factors (BCFs) of PFECHS ranged from 324 ± 97 to 435 ± 89 L/kg and from 454 ± 60 to 576 ± 86 L/kg in the brain and eyes of medaka, respectively. The BCFs of trans-PFECHS were higher than those of cis-PFECHS. PFECHS exposure significantly altered γ-aminobutyric acid (GABA) levels in the medaka brain and disrupted the GABAergic system, as revealed by proteomics, implying that PFECHS can disturb neural signal transduction like PFOS. PFECHS exposure resulted in significant alterations in multiple proteins associated with eye function in medaka. Abnormal locomotion was observed in PFECHS-exposed medaka larvae, which was rescued by adding exogenous GABA, suggesting the involvement of disrupted GABA signaling pathways in PFECHS neurotoxicity.

中文翻译：

---

全氟乙基环己烷磺酸盐在海洋青鳉中的立体选择性生物富集和神经毒性


全氟乙基环己烷磺酸盐 (PFECHS) 是一种新兴的全氟烷基和多氟烷基物质，用于替代全氟辛烷磺酸 (PFOS)，主要用于飞机液压油中。然而，先前的研究表明这种替代化学物质具有潜在的神经毒性。在这项研究中，海洋青鳉 (Oryzias melastigma) 从胚胎阶段就暴露于环境相关浓度的 PFECHS（浓度：0、0.08、0.26 和 0.91 μg/L）90 天。接触后，收集了青鳉的大脑和眼睛，以研究 PFECHS 立体异构体的生物富集潜力及其对神经系统的影响。确定的青鳉大脑和眼睛中 PFECHS 的生物浓度因子 (BCF) 范围分别为 324 ± 97 至 435 ± 89 L/kg 和 454 ± 60 至 576 ± 86 L/kg。反式 PFECHS 的 BCF 高于顺式 PFECHS。蛋白质组学显示，PFECHS 暴露显着改变了青鳉大脑中的 γ-氨基丁酸 (GABA) 水平，并扰乱了 GABA 能系统，这意味着 PFECHS 可以像 PFOS 一样扰乱神经信号转导。 PFECHS 暴露导致青鳉中与眼功能相关的多种蛋白质发生显着改变。在暴露于 PFECHS 的青鳉幼虫中观察到异常运动，通过添加外源 GABA 可以挽救幼虫，这表明 GABA 信号通路被破坏与 PFECHS 神经毒性有关。