Effects of ZnO nanoparticles on perfluorooctane sulfonate induced thyroid-disrupting on zebrafish larvae.
Perfluorooctane sulfonate (PFOS) and ZnO nanoparticles (nano-ZnO) are widely distributed in the environment. However, the potential toxicity of co-exposure to PFOS and nano-ZnO remains to be fully elucidated. The test investigated the effects of co-exposure to PFOS and nano-ZnO on the hypothalamic-pituitary-thyroid (HPT) axis in zebrafish. Zebrafish embryos were exposed to a combination of PFOS (0.2, 0.4, 0.8mg/L) and nano-ZnO (50mg/L) from their early stages of life (0-14days). The whole-body content of TH and the expression of genes and proteins related to the HPT axis were analyzed. The co-exposure decreased the body length and increased the malformation rates compared with exposure to PFOS alone. Co-exposure also increased the triiodothyronine (T3) levels, whereas the thyroxine (T4) content remained unchanged. Compared with the exposure to PFOS alone, exposure to both PFOS (0.8mg/L) and nano-ZnO (50mg/L) significantly up-regulated the expression of corticotropin-releasing factor, sodium/iodidesymporter, iodothyronine deiodinases and thyroid receptors and significantly down-regulated the expression of thyroid-stimulating hormone, thyroglobulin (TG), transthyretin (TTR) and thyroid receptors. The protein expression levels of TG and TTR were also significantly down-regulated in the co-exposure groups. In addition, the expression of the thyroid peroxidase gene was unchanged in all groups. The results demonstrated that PFOS and nano-ZnO co-exposure could cause more serious thyroid-disrupting effects in zebrafish than exposure to PFOS alone. Our results also provide insight into the mechanism of disruption of the thyroid status by PFOS and nano-ZnO.
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China; School of public health, Jia Mu Si University, Jiamusi 154007, China. Electronic address: dujia532158064@163.com.
Jia
J
Du
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. Electronic address: wshutao@126.com.
Shutao
S
Wang
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China; School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China. Electronic address: youhong@hit.edu.cn.
Hong
H
You
The Second Middle School of Funing at Qinhuangdao, Qinhuangdao 066300, China.
Zhongqiang
Z
Liu
D017738:Alkanesulfonic Acids / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D005466:Fluorocarbons / Q000737:chemistry / Q000633:toxicity*; D053758:Nanoparticles / Q000737:chemistry*; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*; D015027:Zebrafish; D015034:Zinc Oxide / Q000737:chemistry*
D017738:Alkanesulfonic Acids; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical; D014284:Triiodothyronine; C076994:perfluorooctane sulfonic acid; D015034:Zinc Oxide
HPT axis; PFOS; nano-ZnO; thyroid hormone; zebrafish