title: The role of apoptosis in MCLR-induced developmental toxicity in zebrafish embryos.
abstract: We previously demonstrated that cyanobacteria-derived microcystin-leucine-arginine (MCLR) is able to induce developing toxicity, such as malformation, growth delay and also decreased heart rates in zebrafish embryos. However, the molecular mechanisms by which MCLR induces its toxicity during the development of zebrafish remain largely unknown. Here, we evaluate the role of apoptosis in MCLR-induced developmental toxicity. Zebrafish embryos were exposed to various concentrations of MCLR (0, 0.2, 0.5, 2, and 5.0 mg L(-1)) for 96 h, at which time reactive oxygen species (ROS) was significantly induced in the 2 and 5.0 mg L(-1) MCLR exposure groups. Acridine orange (AO) staining and terminal deoxynucleotide transferase-mediated deoxy-UTP nick end labelling (TUNEL) assay showed that MCLR exposure resulted in cell apoptosis. To test the apoptotic pathway, the expression pattern of several apoptotic-related genes was examined for the level of enzyme activity, gene and protein expression, respectively. The overall results demonstrate that MCLR induced ROS which consequently triggered apoptosis in the heart of developing zebrafish embryos. Our results also indicate that the p53-Bax-Bcl-2 pathway and the caspase-dependent apoptotic pathway play major roles in MCLR-induced apoptosis in the developing embryos.
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zeng
authors.affiliation: Hubei Maternal and Child Health Hospital, Wuhan 430070, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Sun
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jianghua
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Guirong
authors.initials: G
authors.lastname: Zhang
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Chen
authors.affiliation: Institute of Agricultural Quality Standards & Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064, China. Electronic address: Yanwei75126@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Yan
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China. Electronic address: ligy2001@163.com.
authors.forename: Guangyu
authors.initials: G
authors.lastname: Li
mesh_terms: D000165:Acridine Orange / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D020169:Caspases / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000201:enzymology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D020287:In Situ Nick-End Labeling; D008387:Marine Toxins; D052998:Microcystins / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000502:physiology*
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D020169:Caspases; C057862:cyanoginosin LR; D000165:Acridine Orange
keywords: Apoptosis; Developmental toxicity; Embryo; MCLR; Zebrafish