title: Bioconcentration and transfer of the organophorous flame retardant 1,3-dichloro-2-propyl phosphate causes thyroid endocrine disruption and developmental neurotoxicity in zebrafish larvae.
abstract: Organophosphate flame retardants are emerging environmental contaminants, although knowledge of their health risks is limited. Here, thyroid hormone homeostasis and neuronal development was studied in the progeny of adult zebrafish exposed to tris(1,3-dichloro-2-propyl) phosphate (TDCPP). Adult zebrafish were exposed to TDCPP (0, 4, 20, and 100 μg/L) for 3 months. Increased generation of reactive oxygen species and reduced survival rates was observed in exposed F1 larvae. We also observed a significant decrease in plasma thyroxine and 3,5,3'-triiodothyronine levels in F0 females and F1 eggs/larvae. The mRNA and protein expression of factors associated with neuronal development (e.g., α1-tubulin, myelin basic protein, and synapsin IIa) were significantly downregulated in exposed F1 larvae, as was the level of the neurotransmitters dopamine, serotonin, gamma amino butyric acid, and histamine. Larval locomotion was significantly decreased in exposed fish, but there was no effect on acetylcholinesterase activity. Bioconcentration of TDCPP was observed in F0 fish. TDCPP was also detected in F1 eggs following parental exposure, indicating maternal transfer of this compound. This study uniquely shows that TDCPP can be transferred to the offspring of exposed adults, causing thyroid endocrine disruption and developmental neurotoxicity.
authors.affiliation: †State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.|‡University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Qiangwei
authors.initials: Q
authors.lastname: Wang
authors.affiliation: §State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China.|∥Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for Sustainable Use of Marine Biodiversity, City University of Hong Kong Shenzhen Research Institute Building, Shenzhen, Guangdong 518057, China.|⊥Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
authors.forename: Nelson Lok-Shun
authors.initials: NL
authors.lastname: Lai
authors.affiliation: †State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.|‡University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: †State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.
authors.forename: Yongyong
authors.initials: Y
authors.lastname: Guo
authors.affiliation: §State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China.|∥Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for Sustainable Use of Marine Biodiversity, City University of Hong Kong Shenzhen Research Institute Building, Shenzhen, Guangdong 518057, China.|⊥Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
authors.forename: Paul Kwan-Sing
authors.initials: PK
authors.lastname: Lam
authors.affiliation: ∥Research Centre for the Oceans and Human Health, Shenzhen Key Laboratory for Sustainable Use of Marine Biodiversity, City University of Hong Kong Shenzhen Research Institute Building, Shenzhen, Guangdong 518057, China.
authors.forename: James Chung-Wah
authors.initials: JC
authors.lastname: Lam
authors.affiliation: †State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.
authors.forename: Bingsheng
authors.initials: B
authors.lastname: Zhou
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects; D052244:Endocrine Disruptors / Q000493:pharmacokinetics / Q000633:toxicity*; D005260:Female; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005411:Flame Retardants / Q000493:pharmacokinetics / Q000633:toxicity*; D018507:Gene Expression Regulation, Developmental; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D008297:Male; D020258:Neurotoxicity Syndromes / Q000209:etiology*; D018377:Neurotransmitter Agents / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000493:pharmacokinetics* / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013961:Thyroid Gland / Q000187:drug effects; D013963:Thyroid Hormones / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology / Q000378:metabolism
chemical_list: D052244:Endocrine Disruptors; D029941:Fish Proteins; D005411:Flame Retardants; D018377:Neurotransmitter Agents; D009943:Organophosphorus Compounds; D017382:Reactive Oxygen Species; D013963:Thyroid Hormones; C016805:tris(1,3-dichloro-2-propyl)phosphate; D000110:Acetylcholinesterase