Embryonic Exposure to 2,2′,3,5′,6‐pentachlorobiphenyl (PCB‐95) Causes Developmental Malformations in Zebrafish

Abstract

2,2′,3,5′,6-Pentachlorobiphenyl (PCB-95) is an environmental neurotoxicant. There is accumulated evidence that some neurotoxic effects of PCB-95 are caused by increased spontaneous Ca 2+ oscillations in neurons resulting from modifying ryanodine receptors (RyR) in calcium-releasing channels. However, there are large gaps in explaining brain and other developmental malformations on embryonic PCB-95 exposure. In the present study, we address those deficiencies by studying the toxic effects of PCB-95 using zebrafish as an ontogenetic model. To characterize these effects, zebrafish embryos with intact chorions were exposed to 4 different concentrations of PCB-95 (0.25, 0.5, 0.75, and 1 ppm) for 3 consecutive days. The controls were maintained in 0.5 × E2 medium or egg water and in 0.1% (v/v) dimethyl sulfoxide (DMSO)/0.5 × E2 medium or egg water. PCB-95-treated groups showed dose-dependent decreases in survival and hatching rates, with increased rates of developmental malformations when compared to controls. These include morphological malformations, brain cell necrosis, and smaller eye sizes at 5 d post fertilization. These data suggest potential mechanisms underlying the abnormal behavior observed in a visual stimulus assay. The present study provides insight into PCB-95induced developmental toxicity and supports the use of the zebrafish model in understanding the effects of PCB-95 exposure. Environ Toxicol Chem 2020;39:162-170. © 2019 SETAC The Tg(elavl3:EGFP) line, maintained at Brown University, expresses enhanced green fluorescent protein and was utilized wileyonlinelibrary.com/ETC © 2019 SETAC Embryonic PCB-95 exposure and developmental malformations-Environmental Toxicology and Chemistry, 2020;39:162-170 Zhang XQ, Yang L, Zhang M, Guo X, Chi X. 2015. PCB1254 exposure contributes to the abnormalities of optomotor responses and influence of the photoreceptor cell development in zebrafish larvae. Ecotoxicol Environ Saf 118:133-138.

Ryanodine receptor-active non-dioxin-like polychlorinated biphenyls cause neurobehavioral deficits in larval zebrafish

“…Our teratogenic results are consistent with previously published work that reported no malformations or mortality in larval zebrafish younger than 7 dpf statically exposed to PCB 153 at concentrations as high as 10 μM ( Aluru et al, 2020 ). However, our results differ from other studies that showed developmental exposures to PCB 95 caused malformations ( Ranasinghe et al, 2020 ). This discrepancy may reflect the different exposure paradigms employed between studies.…”

Xenobiotics Targeting Cardiolipin Metabolism to Promote Thrombosis in Zebrafish

“…The zebrafish maintenance protocol and all of the reagents used are shown in Table S1. The dose concentrations were referenced from previous studies − and confirmed with preliminary exposure experiments. As shown in Table , three doses of chemicals (high, medium, and low doses) were used in the embryo exposure experiments, wherein the medium- and low-dose concentrations were mostly comparable to those reported in environmental water samples. − The in vivo concentrations of the chemicals were also determined in the exposed embryos to confirm that they matched the environmentally relevant concentrations (Table ).…”

Rapid Assessment of Ocular Toxicity from Environmental Contaminants Based on Visually Mediated Zebrafish Behavior Studies

“…Previous research has demonstrated that zebrafish larvae exposed to MPs, Cu, prednisolone, PCB-95, and combined exposures of Cu and MPs exhibit abnormal behavior during early developmental stages. These abnormalities manifest as either a lack of significant avoidance response towards visual stimuli or reduced avoidance behavior [ 49 , 88 , 89 ].…”