PUBLICATION

6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), a novel perfluorooctane sulfonate alternative, induced developmental toxicity in zebrafish embryos

Authors
Shi, G., Xie, Y., Guo, Y., Dai, J.
ID
ZDB-PUB-171219-7
Date
2017
Source
Aquatic toxicology (Amsterdam, Netherlands)   195: 24-32 (Journal)
Registered Authors
Keywords
6:2 FTAB, Cell apoptosis, Developmental toxicity, Immunotoxicity, Oxidative stress, Zebrafish embryos
MeSH Terms
  • Alkanesulfonic Acids/chemistry
  • Alkanesulfonic Acids/toxicity*
  • Animals
  • Apoptosis/drug effects
  • Caspases/metabolism
  • Embryo, Nonmammalian/drug effects*
  • Embryo, Nonmammalian/pathology
  • Fluorocarbons/chemistry
  • Fluorocarbons/toxicity*
  • Gene Expression Regulation, Developmental/drug effects
  • Immune System/drug effects
  • Immunity, Innate/drug effects
  • Oxidative Stress/drug effects
  • Sulfonamides/chemistry
  • Sulfonamides/toxicity*
  • Transcription, Genetic/drug effects
  • Water Pollutants, Chemical/toxicity
  • Zebrafish/embryology*
  • Zebrafish/genetics
  • Zebrafish/immunology
  • Zebrafish Proteins/metabolism
PubMed
29247975 Full text @ Aquat. Toxicol.
Abstract
6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB) is a major component of Forafac®1157, a novel perfluorooctane sulfonate (PFOS) alternative used globally in aqueous film forming foams (AFFFs). Although 6:2 FTAB has been recently detected in the aquatic environment, its toxic effects on aquatic organisms remain unclear. Here, zebrafish embryos were exposed to various concentrations of 6:2 FTAB (0, 5, 10, 20, 40, 60, 80, and 100 mg/L) from 6 to 120 h post-fertilization (hpf) to investigate its developmental toxicity and possible mechanism of action. Results showed that exposure to 40 mg/L or higher concentrations of 6:2 FTAB significantly decreased the survival percentage and increased the malformation percentage. The median lethal concentration (LC50) at 120 hpf was 43.73 ± 3.24 mg/L, and the corresponding benchmark dose lower limit (BMDL) of lethal effect was 33.79 mg/L. These values were both higher than those for PFOS, supporting the notion that 6:2 FTAB is less toxic than PFOS to zebrafish embryos. The most common developmental defect in 6:2 FTAB-treated embryos was rough-edged skin/fins. TUNEL assay showed that 6:2 FTAB exposure induced cell apoptosis in the tail region compared with that of the control, which might explain the rough-edged skin/fins. The increased transcriptional levels of p53, bax, and apaf1 and the increased activities of caspase-3, -8, and -9 provided further evidence of 6:2 FTAB-induced apoptosis. We also analyzed the effects of 6:2 FTAB on oxidative stress and the immune system. Results showed that reactive oxygen species and malondialdehyde accumulated in concentration-dependent manners after exposure to 6:2 FTAB, and antioxidant enzyme activities (catalase and glutathione peroxidase) also changed. Exposure to 6:2 FTAB also altered the transcriptional levels of ccl1, il-1β, il-8, tnfα, ifn, and cxcl-c1c, which play important roles in the innate immune system. Collectively, our data suggest that 6:2 FTAB exposure can induce cell apoptosis, oxidative stress, and immunotoxicity, thus highlighting the developmental toxicity of 6:2 FTAB in zebrafish embryos.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping