title: Cadmium sulfate and CdTe-quantum dots alter DNA repair in zebrafish (Danio rerio) liver cells.
abstract: Increasing use of quantum dots (QDs) makes it necessary to evaluate their toxicological impacts on aquatic organisms, since their contamination of surface water is inevitable. This study compares the genotoxic effects of ionic Cd versus CdTe nanocrystals in zebrafish hepatocytes. After 24h of CdSO4 or CdTe QD exposure, zebrafish liver (ZFL) cells showed a decreased number of viable cells, an accumulation of Cd, an increased formation of reactive oxygen species (ROS), and an induction of DNA strand breaks. Measured levels of stress defense and DNA repair genes were elevated in both cases. However, removal of bulky DNA adducts by nucleotide excision repair (NER) was inhibited with CdSO4 but not with CdTe QDs. The adverse effects caused by acute exposure of CdTe QDs might be mediated through differing mechanisms than those resulting from ionic cadmium toxicity, and studying the effects of metallic components may be not enough to explain QD toxicities in aquatic organisms.
authors.affiliation: The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX 79416, USA.
authors.forename: Song
authors.initials: S
authors.lastname: Tang
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Cai
authors.forename: Hicham
authors.initials: H
authors.lastname: Chibli
authors.forename: Vinay
authors.initials: V
authors.lastname: Allagadda
authors.forename: Jay L
authors.initials: JL
authors.lastname: Nadeau
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Mayer
mesh_terms: D000818:Animals; D019187:Cadmium Compounds / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004260:DNA Repair; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D045663:Quantum Dots; D017382:Reactive Oxygen Species / Q000378:metabolism; D013431:Sulfates / Q000737:chemistry / Q000633:toxicity*; D013691:Tellurium / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D015027:Zebrafish
chemical_list: D019187:Cadmium Compounds; D017382:Reactive Oxygen Species; D013431:Sulfates; D014874:Water Pollutants, Chemical; C037123:cadmium sulfate; D013691:Tellurium; C028337:cadmium telluride
keywords: BER; Cadmium; Cd; CdTe; DNA repair; GFAAS; Genotoxic; MMR; MPA; MT; NER; NHEJ; PCoA; QDs; Quantum dots; ROS; Reactive oxygen species; SOD; TEM; ZFL; Zebrafish; base excision repair; cadmium; cadmium telluride; graphite furnace atomic absorption spectrometry; mercaptopropionic acid; metallothionein; mismatch repair; non-homologous end joining; nucleotide excision repair; principal coordinate analysis; quantum dots; reactive oxygen species; superoxide dismutase; transmission electron microscope; zebrafish liver cells