title: Involvement of oxidative stress and cytoskeletal disruption in microcystin-induced apoptosis in CIK cells.
abstract: The outbreak of cyanobacterial blooms induces the production and release of microcystins (MCs) into water, representing a health hazard to aquatic organisms and even humans. Some recent studies have suggested that kidney is another important target organ of MCs except liver, however, the potential toxicity mechanisms are still unclear. In this study, we first investigated the collaborative effect of oxidative stress and cytoskeletal disruption in microcystin-induced apoptosis in CIK (Ctenopharyngodon idellus kidney) cells in vitro. CIK cells were treated with 0, 1, 10, and 100μg/L microcystin-LR (MC-LR) for 24 and 48h. Cell viability was increased by MC-LR in 1μg/L group, while decreased in 100μg/L group at 48h. Cell cycle assay showed that 1 and 10μg/L MC-LR induced cell cycle through G1 into S and G2/M phases, while 100μg/L MC-LR reduced G2/M phase population. MC-LR markedly induced apoptosis in 10 and 100μg/L groups. Elevated reactive oxygen species (ROS) production, increased malondialdehyde (MDA) contents, decreased glutathione (GSH) levels, and modulated antioxidant enzymes including catalase (CAT) and superoxide dismutase (SOD) were observed in CIK cells exposed to MC-LR. These alterations were more pronounced at higher doses (10 and 100μg/L), indicating that oxidative stress was induced by MC-LR. Laser scanning confocal microscope observation showed aggregation and collapse of microfilaments (MFs) and microtubules (MTs) in CIK cells, and even loss of some cytoskeleton structure. Moreover, transcriptional changes of cytoskeletal genes (β-actin, lc3a, and keratin) were also determined, which have a high probability with cytoskeleton structure damage. Our data suggest that oxidative stress and cytoskeletal disruption may interact with each other and jointly lead to apoptosis and renal toxicity induced by MCs.
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Huang
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Wanjing
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Qiao
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Wu
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wen
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Cuihong
authors.initials: C
authors.lastname: Huang
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Tang
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China. Electronic address: xuezhen@mail.hzau.edu.cn.
authors.forename: Xuezhen
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002347:Carps / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D000458:Cyanobacteria / Q000378:metabolism; D055612:Cytokine-Induced Killer Cells / Q000187:drug effects*; D004789:Enzyme Activation / Q000187:drug effects; D008099:Liver / Q000187:drug effects; D052998:Microcystins / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D010088:Oxidoreductases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D052998:Microcystins; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; C078588:microcystin; D010088:Oxidoreductases
keywords: Apoptosis; CIK cell; Cytoskeleton; Microcystin-LR; Nephrotoxicity; Oxidative stress