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It has been reported that exposure to perfluorooctane sulfonates (PFOS) causes behavioral abnormalities in zebrafish larvae, but the possible mechanisms underlying these changes remain unexplored. In this study, zebrafish embryos (2 h postfertilization, 2-hpf) were exposed to PFOS at different concentrations (0, 0.032, 0.32 and 3.2 mg/L) for 120 h. Developmental endpoints and the locomotion behavior of larvae were evaluated. Reactive oxygen species (ROS) levels, dopamine contents, several genes and proteins related to neurodevelopment and dopamine signaling were examined. Our results indicate that increased ROS levels in the zebrafish larvae heads may be causally associated with neurodevelopment damage. Meanwhile, brain-derived neurotrophic factor (BDNF) and alpha1-Tubulin (α1-Tubulin) protein contents were significantly increased, which may be a compensatory mechanism for the impaired central nervous system. PFOS-induced locomotor hyperactivity was observed in the first light phase and dark phase at the 0.32 and 3.2 mg/L of PFOS. Upregulation of dopamine-related genes tyrosine hydroxylase (th) and dopamine transporter (dat) associated with increased dopamine contents in the 3.2 mg/L of PFOS. In addition, protein expression of TH and DAT were noted at the 0.32 and 3.2 mg/L of PFOS concentrations. Our results suggested that PFOS induces neurobehavioral changes in zebrafish larvae, possibly by perturbing a dopamine signaling pathway. In addition, PFOS induced development damage, such as increased malformation rate and shorter body length.

Purpose Perfluoroalkyl substances (PFASs) are a class of manmade chemicals commonly used in consumer product manufacturing. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are two of the most highly studied PFASs. Both are present in the blood of the most Americans. PFASs are associated with intermediate cardiovascular disease (CVD) outcomes, but their relationship with obesity, a risk factor for intermediate and advanced CVD, remains largely unconfirmed. In this context, we aimed to explore the relationship between PFASs and both overweight/obesity and abdominal obesity among children. Methods We examine associations between PFOA and PFOS levels, and Body Mass Index (BMI) and waist circumference (WC) in a representative sample (N = 2473) of US children, aged 12–18 years from the Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey 1999–2012. Overweight/obesity is defined as age-, sex-specific BMI z-score ≥ 85th percentile; abdominal obesity is defined as age-, sex-specific waist circumference ≥90th percentile. Results Associations between PFASs and anthropometric outcomes show a dose-response relationship overall. For overweight/obese BMI z-score, findings indicate OR = 1.42 and 95% CI: 0.85–2.38 for quartile 2 of PFOA exposure; OR = 2.22 (95% CI: 1.20–4.13) for quartile 3 of PFOA exposure; and OR = 2.73 (95% CI:1.10–6.74) for quartile 4 of PFOA exposure. Discussion Findings indicate an association between elevated PFOA and overweight/obesity among children after multivariable adjustment.