title: Silver nanoparticles disrupt regulation of steroidogenesis in fish ovarian cells.
abstract: Despite the influx of silver nanoparticles (nAg) into the marine environment, their effects on fish reproduction remain completely unexplored. Using ovarian primary cells from marine medaka (Oryzias melastigma), in vitro studies were carried out to evaluate the effects of two differently coated nAg particles (Oleic Acid, (OA) nAg and Polyvinylpyrrolidone, (PVP) nAg) on fish ovarian tissues, using AgNO3 as a positive control. Cytotoxicity was evaluated by MTT assay and expression of key genes regulating steroidogenesis (StAR, CYP 19a, CYP 11a, 3βHSD and 20βHSD) were determined by Q-RT-PCR. EC50 values for PVP nAg, OA nAg and AgNO3 were 7.25μgL(-1), 924.4μgL(-1), and 42.0μgL(-1) respectively, showing that toxicity of silver was greatly enhanced in the PVP coated nano-form. Down regulation of CYP 19a was observed in both nAg and AgNO3 treatments, while down regulation of 3βHSD was only found in the OA nAg and AgNO3 treatments. For the first time, our results demonstrated that nAg can affect specific genes regulating steroidogenesis, implicating nAg as a potential endocrine disruptor.
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region.
authors.forename: Natalie
authors.initials: N
authors.lastname: Degger
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region.
authors.forename: Anna C K
authors.initials: AC
authors.lastname: Tse
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong Special Administrative Region. Electronic address: rudolfwu@hku.hk.
authors.forename: Rudolf S S
authors.initials: RS
authors.lastname: Wu
mesh_terms: D000818:Animals; D005260:Female; D029941:Fish Proteins / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects*; D053768:Metal Nanoparticles / Q000633:toxicity*; D019301:Oleic Acid / Q000633:toxicity; D009990:Oryzias / Q000502:physiology*; D010053:Ovary / Q000187:drug effects*; D011205:Povidone / Q000633:toxicity; D012834:Silver / Q000633:toxicity*; D012835:Silver Nitrate / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D029941:Fish Proteins; D014874:Water Pollutants, Chemical; D019301:Oleic Acid; D012834:Silver; D012835:Silver Nitrate; D011205:Povidone
keywords: Endocrine disruption; Marine medaka; Primary cell culture; Silver nanoparticles; Steroidogenesis; in vitro