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Qiu J, Zhang J, Li A. Cytotoxicity and intestinal permeability of phycotoxins assessed by the human Caco-2 cell model. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 249:114447. [PMID: 38321666 DOI: 10.1016/j.ecoenv.2022.114447] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/05/2022] [Accepted: 12/16/2022] [Indexed: 02/08/2024]
Abstract
Phycotoxins are a class of multiple natural metabolites produced by microalgae in marine and freshwater ecosystems that bioaccumulate in food webs, particularly in shellfish, having a great impact on human health. Phycotoxins are mainly leached and absorbed in the small intestine when human consumers accidentally ingest toxic aquatic products contaminated by them. To assess the intestinal uptake and damage of phycotoxins, a typical in vitro model was developed and widely applied using the human colorectal adenocarcinoma Caco-2 cell line. In this review, the application cases were summarized for multiple phycotoxins, including microcystins (MCs), cylindrospermopsins (CYNs), domoic acids (DAs), saxitoxins (STXs), palytoxins (PLTXs), okadaic acids (OAs), pectenotoxins (PTXs) and azaspiracids (AZAs). The results of the previous studies showed that each group of phycotoxins presented different cytotoxicity and mechanisms to Caco-2 cells, and significant discrepancies in the transport of phycotoxin across the Caco-2 cell monolayers. Therefore, this review describes the evaluation assays of the Caco-2 cell monolayer model, illustrates the principles of several primary cytotoxicity evaluation assays, and summarizes the cytotoxicity of each group of phycotoxins to Caco-2 cells line and their cellular transport, and finally proposes the development of multicellular intestinal models for future comprehensive studies on the toxicity and absorption of phycotoxins in the intestine. It will improve the understanding of Caco-2 cell monolayer models in the toxicology studies on phycotoxins and the potentially detrimental effects of microalgal toxins on the human intestine.
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Affiliation(s)
- Jiangbing Qiu
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China
| | - Jingrui Zhang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Aifeng Li
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China.
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2
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Henri J, Lanceleur R, Delmas JM, Fessard V, Huguet A. Permeability of the Cyanotoxin Microcystin-RR across a Caco-2 Cells Monolayer. Toxins (Basel) 2021; 13:toxins13030178. [PMID: 33673481 PMCID: PMC7997155 DOI: 10.3390/toxins13030178] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 12/27/2022] Open
Abstract
Microcystins (MCs) are toxins produced by several cyanobacterial species found worldwide. While MCs have a common structure, the variation of two amino acids in their structure affects their toxicity. As toxicodynamics are very similar between the MC variants, their differential toxicity could rather be explained by toxicokinetic parameters. Microcystin-RR (MC-RR) is the second most abundant congener and induces toxicity through oral exposure. As intestinal permeability is a key parameter of oral toxicokinetics, the apparent permeability of MC-RR across a differentiated intestinal Caco-2 cell monolayer was investigated. We observed a rapid and large decrease of MC-RR levels in the donor compartment. However, irrespective of the loaded concentration and exposure time, the permeabilities were very low from apical to basolateral compartments (from 4 to 15 × 10−8 cm·s−1) and from basolateral to apical compartments (from 2 to 37 × 10−8 cm·s−1). Our results suggested that MC-RR would be poorly absorbed orally. As similar low permeability was reported for the most abundant congener microcystin-LR, and this variant presented a greater acute oral toxicity than MC-RR, we concluded that the intestinal permeability was probably not involved in the differential toxicity between them, in contrast to the hepatic uptake and metabolism.
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Wang Y, Xiao X, Wang F, Yang Z, Yue J, Shi J, Ke F, Xie Z, Fan Y. An identified PfHMGB1 promotes microcystin-LR-induced liver injury of yellow catfish (Pelteobagrus fulvidraco). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 207:111266. [PMID: 32919194 DOI: 10.1016/j.ecoenv.2020.111266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
Microcystin-LR (MC-LR) is a potent hepatotoxin that can cause liver inflammation and injury. However, the mode of action of related inflammatory factors is not fully understood. PfHMGB1 is an inflammatory factor induced at the mRNA level in the liver of juvenile yellow catfish (Pelteobagrus fulvidraco) that were intraperitoneally injected with 50 μg/kg MC-LR. The PfHMGB1 mRNA level was highest in the liver and muscle among 11 tissues examined. The full-length cDNA sequence of PfHMGB1 was cloned and overexpressed in E. coli, and the purified protein rPfHMGB1 demonstrated DNA binding affinity. Endotoxin-free rPfHMGB1 (6-150 μg/mL) also showed dose-dependent hepatotoxicity and induced inflammatory gene expression of primary hepatocytes. PfHMGB1 antibody (anti-PfHMGB1) in vitro reduced MC-LR (30 and 50 μmol/L)-induced hepatotoxicity, suggesting PfHMGB1 is important in the toxic effects of MC-LR. In vivo study showed that MC-LR upregulated PfHMGB1 protein in the liver. The anti-PfHMGB1 blocked its counterpart and reduced ALT/AST activities after MC-LR exposure. Anti-PfHMGB1 partly neutralized MC-LR-induced hepatocyte disorganization, nucleus shrinkage, mitochondria, and rough endoplasmic reticula destruction. These findings suggest that PfHMGB1 promotes MC-LR-induced liver damage in the yellow catfish. HMGB1 may help protect catfish against widespread microcystin pollution.
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Affiliation(s)
- Yun Wang
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Hubei Province, Wuhan, 430056, China; Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China.
| | - Xiaoxue Xiao
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Feijie Wang
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Zupeng Yang
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Jingkai Yue
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Jiale Shi
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Fei Ke
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Zhaohui Xie
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
| | - Yanru Fan
- Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, 467036, China
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Vašíček O, Hájek J, Bláhová L, Hrouzek P, Babica P, Kubala L, Šindlerová L. Cyanobacterial lipopeptides puwainaphycins and minutissamides induce disruptive and pro-inflammatory processes in Caco-2 human intestinal barrier model. HARMFUL ALGAE 2020; 96:101849. [PMID: 32560836 DOI: 10.1016/j.hal.2020.101849] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 05/24/2023]
Abstract
Puwainaphycins (PUW) and minutissamides (MIN) are cyanobacterial lipopeptides found in various cyanobacterial species. The first possible target of human exposure to them is intestinal epithelium but effect of PUW/MIN on enterocytes is not known at all. Using differentiated Caco-2 cells, PUW F was found to be cytotoxic from 5 µM concentration based on lactate dehydrogenase release assay and total protein concentration. However, it is also able to induce production of interleukin 8 in non-cytotoxic concentrations 1 and 2.5 µM detected by ELISA. Effects of MIN A and C were similar but less pronounced compared to PUW F. On the other hand, MIN D was the least toxic compound with no significant pro-inflammatory effects. Surprisingly, pro-inflammatory activation of the cells by PUW F and MIN C resulted in an increase in tight junction (TJ) protein claudin 4 expression determined by western blot analysis and confirmed by confocal microscopy. Furthermore, decrease in expression of zonula occludens 3, another TJ protein, was observed after the exposure to PUW F. Taken together, these cytotoxic lipopeptides, especially PUW F, are to be studied more deeply due to their capability to activate and/or deregulate human enterocytes in low concentrations.
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Affiliation(s)
- Ondřej Vašíček
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 65, Czech Republic.
| | - Jan Hájek
- Institute of Microbiology, Centre Algatech, The Czech Academy of Sciences, Novohradska 237, Trebon 379 80, Czech Republic.
| | - Lucie Bláhová
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, Brno 625 00, Czech Republic.
| | - Pavel Hrouzek
- Institute of Microbiology, Centre Algatech, The Czech Academy of Sciences, Novohradska 237, Trebon 379 80, Czech Republic.
| | - Pavel Babica
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, Brno 625 00, Czech Republic; Institute of Botany, The Czech Academy of Sciences, Lidická 25/27, Brno 602 00, Czech Republic.
| | - Lukáš Kubala
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 65, Czech Republic.
| | - Lenka Šindlerová
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno 612 65, Czech Republic.
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Brózman O, Kubickova B, Babica P, Laboha P. Microcystin-LR Does Not Alter Cell Survival and Intracellular Signaling in Human Bronchial Epithelial Cells. Toxins (Basel) 2020; 12:E165. [PMID: 32156079 PMCID: PMC7150819 DOI: 10.3390/toxins12030165] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 01/18/2023] Open
Abstract
Changes in ecological and environmental factors lead to an increased occurrence of cyanobacterial water blooms, while secondary metabolites-producing cyanobacteria pose a threat to both environmental and human health. Apart from oral and dermal exposure, humans may be exposed via inhalation and/or swallowing of contaminated water and aerosols. Although many studies deal with liver toxicity, less information about the effects in the respiratory system is available. We investigated the effects of a prevalent cyanotoxin, microcystin-LR (MC-LR), using respiratory system-relevant human bronchial epithelial (HBE) cells. The expression of specific organic-anion-transporting polypeptides was evaluated, and the western blot analysis revealed the formation and accumulation of MC-LR protein adducts in exposed cells. However, MC-LR up to 20 μM neither caused significant cytotoxic effects according to multiple viability endpoints after 48-h exposure, nor reduced impedance (cell layer integrity) over 96 h. Time-dependent increase of putative MC-LR adducts with protein phosphatases was not associated with activation of mitogen-activated protein kinases ERK1/2 and p38 during 48-h exposure in HBE cells. Future studies addressing human health risks associated with inhalation of toxic cyanobacteria and cyanotoxins should focus on complex environmental samples of cyanobacterial blooms and alterations of additional non-cytotoxic endpoints while adopting more advanced in vitro models.
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Affiliation(s)
- Ondřej Brózman
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic; (O.B.); (B.K.); (P.B.)
| | - Barbara Kubickova
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic; (O.B.); (B.K.); (P.B.)
| | - Pavel Babica
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic; (O.B.); (B.K.); (P.B.)
- Department of Experimental Phycology and Ecotoxicology, Institute of Botany, Czech Academy of Sciences, Brno 60200, Czech Republic
| | - Petra Laboha
- RECETOX, Faculty of Science, Masaryk University, Brno 62500, Czech Republic; (O.B.); (B.K.); (P.B.)
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Tavares D, Paulino MG, Terezan AP, Batista Fernandes J, Giani A, Fernandes MN. Osmoregulatory disturbance in Neotropical fish exposed to the crude extracts of the cyanobacterium, Radiocystis fernandoi. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 216:105315. [PMID: 31561138 DOI: 10.1016/j.aquatox.2019.105315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
Blooms of cyanobacteria, a common event in eutrophic environments, result in the release of potentially toxic substances into the water. The cyanobacterium Radiocystis fernandoi produces microcystin (MC) and other peptides that may disturb homeostasis. This study evaluated the effect of intraperitoneal injections containing the crude extract (CE) of R. fernandoi strain R28 on the gills and kidneys of neotropical fish, Piaractus mesopotamicus, 3, 6 and 24 h post-injection. CE contained MC-RR, MC-YR and minor other oligopeptides. Plasma ions and the activities of the enzymes PP1 and PP2A, Na+/K+-ATPase (NKA), H+-ATPase (HA) and carbonic anhydrase (CA) were determined and morphological changes in both the gills and kidneys were characterized. Compared to controls, the concentration of Na+ within the plasma of P. mesopotamicus decreased after treatment with CE 3 h post treatment and increased after 24 h; the concentration of K+ decreased after 6 h. The activity of the endogenous PP1 and PP2A was unchanged in the gills and was inhibited in the kidneys 6 h after i.p. injection. In the gills, NKA activity increased after 3 h and decreased 6 h post i.p. exposure. Further, NKA activity did not differ from the controls 24-h post injection. In the kidneys, NKA, HA and CA activities were unaffected by treatment. The mitochondria-rich cell (MRC) density in the gills decreased after 3 h in the filament and 3 and 6 h in the lamellae and was restored to the control levels 24 h post-exposure. Filament epithelial hyperplasia and hypertrophy, lamellar atrophy and rupture of the lamellar epithelium were the most common effects of treatment in the gills. No histopathological changes occurred in the kidneys. This study demonstrates that a single dose of toxic CE from R. fernandoi can cause a transitory ion imbalance in P. mesopotamicus which is related to the changes in MRC levels and NKA activity. Ionic balance was recovered 24 h post i.p. injection, however, morphological changes that occurred in the gills took a longer amount of time to return to normal. To conclude, the effects of components contained within the CE of R. fernandoi may be harmful to P. mesopotamicus. In particular, the recovery of ionic regulation depends on MRC responses and histopathological changes produced by CE may affect gas exchange and other gill functions.
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Affiliation(s)
- Driele Tavares
- Department of Physiological Sciences, Federal University of São Carlos, Rodovia Washington Luiz km 235, 13565-905 São Carlos, São Paulo, Brazil
| | - Marcelo Gustavo Paulino
- Department of Physiological Sciences, Federal University of São Carlos, Rodovia Washington Luiz km 235, 13565-905 São Carlos, São Paulo, Brazil
| | - Ana Paula Terezan
- Department of Chemistry, Federal University of São Carlos, Rodovia Washington Luiz km 235, 13565-905 São Carlos, São Paulo, Brazil
| | - João Batista Fernandes
- Department of Chemistry, Federal University of São Carlos, Rodovia Washington Luiz km 235, 13565-905 São Carlos, São Paulo, Brazil
| | - Alessandra Giani
- Department of Botany, Federal University of Minas Gerais, Av. Pres. Antônio Carlos, 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
| | - Marisa Narciso Fernandes
- Department of Physiological Sciences, Federal University of São Carlos, Rodovia Washington Luiz km 235, 13565-905 São Carlos, São Paulo, Brazil.
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7
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Cao L, Massey IY, Feng H, Yang F. A Review of Cardiovascular Toxicity of Microcystins. Toxins (Basel) 2019; 11:toxins11090507. [PMID: 31480273 PMCID: PMC6783932 DOI: 10.3390/toxins11090507] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 12/30/2022] Open
Abstract
The mortality rate of cardiovascular diseases (CVD) in China is on the rise. The increasing burden of CVD in China has become a major public health problem. Cyanobacterial blooms have been recently considered a global environmental concern. Microcystins (MCs) are the secondary products of cyanobacteria metabolism and the most harmful cyanotoxin found in water bodies. Recent studies provide strong evidence of positive associations between MC exposure and cardiotoxicity, representing a threat to human cardiovascular health. This review focuses on the effects of MCs on the cardiovascular system and provides some evidence that CVD could be induced by MCs. We summarized the current knowledge of the cardiovascular toxicity of MCs, with regard to direct cardiovascular toxicity and indirect cardiovascular toxicity. Toxicity of MCs is mainly governed by the increasing level of reactive oxygen species (ROS), oxidative stress in mitochondria and endoplasmic reticulum, the inhibition activities of serine/threonine protein phosphatase 1 (PP1) and 2A (PP2A) and the destruction of cytoskeletons, which finally induce the occurrence of CVD. To protect human health from the threat of MCs, this paper also puts forward some directions for further research.
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Affiliation(s)
- Linghui Cao
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha 410078, Hunan, China
| | - Isaac Yaw Massey
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha 410078, Hunan, China
| | - Hai Feng
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha 410078, Hunan, China
| | - Fei Yang
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha 410078, Hunan, China.
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Díez-Quijada L, Puerto M, Gutiérrez-Praena D, Llana-Ruiz-Cabello M, Jos A, Cameán AM. Microcystin-RR: Occurrence, content in water and food and toxicological studies. A review. ENVIRONMENTAL RESEARCH 2019; 168:467-489. [PMID: 30399604 DOI: 10.1016/j.envres.2018.07.019] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/09/2018] [Accepted: 07/09/2018] [Indexed: 06/08/2023]
Abstract
Microcystins (MCs) are hepatotoxins, produced by various species of cyanobacteria, whose occurrence is increasing worldwide owing to climate change and anthropogenic activities. More than 100 variants have been reported, and among them MC-LR is the most extensively studied, but there are other MC congeners that deserve to be investigated. The need for data to characterize the toxicological profile of MC variants other than MC-LR has been identified in order to improve risk assessment in humans and wildlife. Accordingly, the aim of this study was to evaluate the information available in the scientific literature dealing with MC-RR, as this congener is the second most common cyanotoxin in the environment. The review focuses on aspects such as occurrence in water and food, and toxicity studies both in vitro and in vivo. It reveals that, although MC-RR is a real hazard with a high exposure potential in some countries, little is known yet about its specific toxicological properties that differ from those of MC-LR, and important aspects such as genotoxicity and chronic effects have not yet been sufficiently addressed.
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Affiliation(s)
- Leticia Díez-Quijada
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Sevilla, Spain
| | - María Puerto
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Sevilla, Spain.
| | - Daniel Gutiérrez-Praena
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Sevilla, Spain
| | - María Llana-Ruiz-Cabello
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Sevilla, Spain
| | - Angeles Jos
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Sevilla, Spain
| | - Ana M Cameán
- Area of Toxicology, Faculty of Pharmacy, Universidad de Sevilla, C/Profesor García González 2, 41012 Sevilla, Spain
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Wu JX, Huang H, Yang L, Zhang XF, Zhang SS, Liu HH, Wang YQ, Yuan L, Cheng XM, Zhuang DG, Zhang HZ. Gastrointestinal toxicity induced by microcystins. World J Clin Cases 2018; 6:344-354. [PMID: 30283797 PMCID: PMC6163130 DOI: 10.12998/wjcc.v6.i10.344] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/08/2018] [Accepted: 06/28/2018] [Indexed: 02/05/2023] Open
Abstract
Microcystins (MCs) are produced by certain bloom-forming cyanobacteria that can induce toxicity in various organs, including renal toxicity, reproductive toxicity, cardiotoxicity, and immunosuppressive effects. It has been a significant global environmental issue due to its harm to the aquatic environment and human health. Numerous investigators have demonstrated that MC exposure can induce a widespread epidemic of enterogastritis with symptoms similar to food poisoning in areas close to lakes. Both in vivo and in vitro studies have provided evidence of positive associations between MC exposure and gastrointestinal toxicity. The toxicity of MCs on the gastrointestinal tract is multidimensional. MCs can affect gastrointestinal barrier function and shift the structure of gut microbiota in different gut regions. Furthermore, MCs can inhibit the secretion of gastrointestinal digestive enzymes and the release of inflammatory cytokines, which affects the expression of immune-related genes in the intestine. The damage of the intestine is closely correlated to MC exposure because the intestine is the main site for the digestion and absorption of nutrients. The damage to the gastrointestinal tract due to MCs was summarized from different aspects, which can be used as a foundation for further exploration of molecular damage mechanisms.
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Affiliation(s)
- Jin-Xia Wu
- Department of Environmental Hygiene, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Hui Huang
- Department of Environmental Hygiene, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Lei Yang
- Department of Nutriology, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Xiao-Feng Zhang
- Department of Nutriology, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Shen-Shen Zhang
- Department of Nutriology, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Hao-Hao Liu
- Department of Environmental Hygiene, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Yue-Qin Wang
- Department of Environmental Hygiene, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Le Yuan
- Department of Environmental Hygiene, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Xue-Min Cheng
- Department of Environmental Hygiene, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Dong-Gang Zhuang
- Department of Environmental Hygiene, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Hui-Zhen Zhang
- Department of Environmental Hygiene, College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan Province, China
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Meneely JP, Hajšlová J, Krska R, Elliott CT. Assessing the combined toxicity of the natural toxins, aflatoxin B 1, fumonisin B 1 and microcystin-LR by high content analysis. Food Chem Toxicol 2018; 121:527-540. [PMID: 30253246 DOI: 10.1016/j.fct.2018.09.052] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 09/20/2018] [Accepted: 09/22/2018] [Indexed: 12/19/2022]
Abstract
As human co-exposure to natural toxins through food and water is inevitable, risk assessments to safeguard health are necessary. Aflatoxin B1 and fumonisin B1, frequent co-contaminants of maize and microcystin-LR, produced in freshwater by cyanobacteria are all naturally occurring potent toxins that threaten human health. Populations in the poorest regions of the world may suffer repeated simultaneous exposure to these contaminants. Using High Content Analysis, multiple cytotoxicity endpoints were measured for the individual toxins and mixtures in various cell lines. Results highlighted that significant cytotoxic effects were observed for aflatoxin B1 in all cell lines while no cytotoxic effects were observed for fumonisin B1 or microcystin-LR. Aflatoxin B1/microcystin-LR was cytotoxic in the order HepG2 > Caco-2 > MDBK. Fumonisin B1/microcystin-LR affected MDBK cells. The ternary mixture was cytotoxic to all cell lines. Most combinations were additive, however antagonism was observed for binary and ternary mixtures in HepG2 and MDBK cell lines at low and high concentrations. Synergy was observed in all cell lines, including at low concentrations. The combination of these natural toxins may pose a significant risk to populations in less developed countries. Furthermore, the study highlights the complexity around trying to regulate for human exposure to multiple contaminants.
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Affiliation(s)
- Julie P Meneely
- Institute for Global Food Security, School of Biological Sciences, Queen's University, Belfast, BT7 1NN, United Kingdom.
| | - Jana Hajšlová
- Faculty of Food & Biochemical Technology, Department of Food Analysis & Nutrition, University of Chemistry & Technology, Technická 3, 166 28, Prague 6, Czech Republic
| | - Rudolf Krska
- Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz Str. 20, 3430, Tulln, Austria
| | - Christopher T Elliott
- Institute for Global Food Security, School of Biological Sciences, Queen's University, Belfast, BT7 1NN, United Kingdom
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11
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Wang X, Xu L, Li X, Chen J, Zhou W, Sun J, Wang Y. The differential effects of microcystin-LR on mitochondrial DNA in the hippocampus and cerebral cortex. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 240:68-76. [PMID: 29729571 DOI: 10.1016/j.envpol.2018.04.103] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 06/08/2023]
Abstract
Microcystin-LR (MC-LR) is the most abundant toxicant among microcystin variants produced by cyanobacteria. MC-induced toxicity is broadly reported to pose a threat to aquatic animals and humans and has been associated with the dysfunction of some organs such as liver and kidney. However, MC-induced neurotoxicity has not been well characterized after long-term exposure. This study was designed to investigate the neurotoxic effects after chronic oral administration of MC-LR. In our trial, C57/BL6 mice received MC-LR at 0, 1, 5, 10, 20 and 40 μg/L in drinking water for twelve months. Our data demonstrated that mitochondrial DNA (mtDNA) damage was evident in the damaged neurons as a result of chronic exposure. Histopathological abnormalities and mtDNA damage were observed in the hippocampus and cerebral cortex. Furthermore, MC-LR exerted distinct effects on these two brain regions. The hippocampus was more susceptible to the treatment of MC-LR compared with the cerebral cortex. However, no strong relationships were observed between the genotoxic effects and exposure doses. In conclusion, this study has provided a mtDNA-related mechanism for underlying chronic neurotoxicity of MC-LR and suggested the presence of differential toxicant effects on the hippocampus and cerebral cortex.
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Affiliation(s)
- Xiaofen Wang
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China
| | - Lizhi Xu
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China; Experimental Center of Basic Medicine, Nanjing University School of Medicine, Nanjing, China
| | - Xinxiu Li
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China
| | - Jingwen Chen
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China
| | - Wei Zhou
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China
| | - Jiapeng Sun
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China
| | - Yaping Wang
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University School of Medicine, Nanjing, China.
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12
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Creed IF, Bergström AK, Trick CG, Grimm NB, Hessen DO, Karlsson J, Kidd KA, Kritzberg E, McKnight DM, Freeman EC, Senar OE, Andersson A, Ask J, Berggren M, Cherif M, Giesler R, Hotchkiss ER, Kortelainen P, Palta MM, Vrede T, Weyhenmeyer GA. Global change-driven effects on dissolved organic matter composition: Implications for food webs of northern lakes. GLOBAL CHANGE BIOLOGY 2018; 24:3692-3714. [PMID: 29543363 DOI: 10.1111/gcb.14129] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/05/2018] [Indexed: 05/21/2023]
Abstract
Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial-aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM)-the messenger between terrestrial and lake ecosystems-with potentially profound effects on the structure and function of lakes. Northern terrestrial ecosystems contain substantial stores of organic matter and filter or funnel DOM, affecting the timing and magnitude of DOM delivery to surface waters. This terrestrial DOM is processed in streams, rivers, and lakes, ultimately shifting its composition, stoichiometry, and bioavailability. Here, we explore the potential consequences of these global change-driven effects for lake food webs at northern latitudes. Notably, we provide evidence that increased allochthonous DOM supply to lakes is overwhelming increased autochthonous DOM supply that potentially results from earlier ice-out and a longer growing season. Furthermore, we assess the potential implications of this shift for the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the food web. We conclude that global change in northern regions leads not only to reduced primary productivity but also to nutritionally poorer lake food webs, with discernible consequences for the trophic web to fish and humans.
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Affiliation(s)
- Irena F Creed
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Charles G Trick
- Interfaculty Program on Public Health & Department of Biology, Western University, London, ON, Canada
| | - Nancy B Grimm
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Dag O Hessen
- Section for Aquatic Biology and Toxicology, University of Oslo, Oslo, Norway
| | - Jan Karlsson
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - Karen A Kidd
- Department of Biology and Canadian Rivers Institute, University of New Brunswick, Saint John, NB, Canada
| | | | | | - Erika C Freeman
- Department of Geography, Western University, London, ON, Canada
| | - Oscar E Senar
- Department of Geography, Western University, London, ON, Canada
| | - Agneta Andersson
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - Jenny Ask
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - Martin Berggren
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
| | - Mehdi Cherif
- Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - Reiner Giesler
- Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
| | - Erin R Hotchkiss
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | | | - Monica M Palta
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Tobias Vrede
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Gesa A Weyhenmeyer
- Department of Ecology and Genetics, Limnology, Uppsala University, Uppsala, Sweden
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13
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Lundqvist J, Pekar H, Oskarsson A. Microcystins activate nuclear factor erythroid 2-related factor 2 (Nrf2) in human liver cells in vitro – Implications for an oxidative stress induction by microcystins. Toxicon 2017; 126:47-50. [DOI: 10.1016/j.toxicon.2016.12.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/16/2016] [Accepted: 12/21/2016] [Indexed: 01/27/2023]
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14
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Buratti FM, Manganelli M, Vichi S, Stefanelli M, Scardala S, Testai E, Funari E. Cyanotoxins: producing organisms, occurrence, toxicity, mechanism of action and human health toxicological risk evaluation. Arch Toxicol 2017; 91:1049-1130. [DOI: 10.1007/s00204-016-1913-6] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 12/13/2016] [Indexed: 12/11/2022]
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15
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Carvalho GMC, Oliveira VR, Casquilho NV, Araujo ACP, Soares RM, Azevedo SMFO, Pires KMP, Valença SS, Zin WA. Pulmonary and hepatic injury after sub-chronic exposure to sublethal doses of microcystin-LR. Toxicon 2016; 112:51-8. [PMID: 26844922 DOI: 10.1016/j.toxicon.2016.01.066] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/21/2016] [Accepted: 01/27/2016] [Indexed: 11/29/2022]
Abstract
We had previously shown that microcystin-LR (MCLR) could induce lung and liver inflammation after acute exposure. The biological outcomes following prolonged exposure to MCLR, although more frequent, are still poorly understood. Thus, we aimed to verify whether repeated doses of MCLR could damage lung and liver and evaluate the dose-dependence of the results. Male Swiss mice received 10 intraperitoneal injections (i.p.) of distilled water (60 μL, CTRL) or different doses of MCLR (5 μg/kg, TOX5), 10 μg/kg (TOX10), 15 μg/kg (TOX15) and 20 μg/kg (TOX20) every other day. On the tenth injection respiratory mechanics (lung resistive and viscoelastic/inhomogeneous pressures, static elastance, and viscoelastic component of elastance) was measured. Lungs and liver were prepared for histology (morphometry and cellularity) and inflammatory mediators (KC and MIP-2) determination. All mechanical parameters and alveolar collapse were significantly higher in TOX5, 10, 15 and 20 than CTRL, but did not differ among them. Lung inflammatory cell content increased dose-dependently in all TOX groups in relation to CTRL, being TOX20 the largest. The production of KC was increased in lung and liver homogenates. MIP-2 increased in the liver of all TOX groups, but in lung homogenates it was significantly higher only in TOX20 group. All TOX mice livers showed steatosis, necrosis, inflammatory foci and a high degree of binucleated hepatocytes. In conclusion, sub-chronic exposure to MCLR damaged lung and liver in all doses, with a more important lung inflammation in TOX20 group.
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Affiliation(s)
| | - Vinícius Rosa Oliveira
- Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Natália Vasconcelos Casquilho
- Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andressa Cristine Pereira Araujo
- Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Raquel Moraes Soares
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sandra Maria F O Azevedo
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Karla Maria Pereira Pires
- Laboratory of Integrative Histology, Institute of Biomedical Sciences, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Samuel Santos Valença
- Laboratory of Integrative Histology, Institute of Biomedical Sciences, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Walter Araujo Zin
- Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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16
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Wang X, Huang P, Liu Y, Du H, Wang X, Wang M, Wang Y, Hei TK, Wu L, Xu A. Role of nitric oxide in the genotoxic response to chronic microcystin-LR exposure in human-hamster hybrid cells. J Environ Sci (China) 2015; 29:210-218. [PMID: 25766030 DOI: 10.1016/j.jes.2014.07.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 05/19/2014] [Accepted: 07/24/2014] [Indexed: 06/04/2023]
Abstract
Microcystin-LR (MC-LR) is the most abundant and toxic microcystin congener and has been classified as a potential human carcinogen (Group 2B) by the International Agency for Research on Cancer. However, the mechanisms underlying the genotoxic effects of MC-LR during chronic exposure are still poorly understood. In the present study, human-hamster hybrid (AL) cells were exposed to MC-LR for varying lengths of time to investigate the role of nitrogen radicals in MC-LR-induced genotoxicity. The mutagenic potential at the CD59 locus was more than 2-fold higher (p<0.01) in AL cells exposed to a cytotoxic concentration (1 μmol/L) of MC-LR for 30 days than in untreated control cells, which was consistent with the formation of micronucleus. MC-LR caused a dose-dependent increase in nitric oxide (NO) production in treated cells. Moreover, this was blocked by concurrent treatment with the NO synthase inhibitor NG-methyl-L-arginine (L-NMMA), which suppressed MC-LR-induced mutations as well. The survival of mitochondrial DNA-depleted (ρ0) AL cells was markedly decreased by MC-LR treatment compared to that in AL cells, while the CD59 mutant fraction was unaltered. These results provided clear evidence that the genotoxicity associated with chronic MC-LR exposure in mammalian cells was mediated by NO and might be considered as a basis for the development of therapeutics that prevent carcinogenesis.
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Affiliation(s)
- Xiaofei Wang
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China; Institute of Intelligent Machines, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China.
| | - Pei Huang
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China.
| | - Yun Liu
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Hua Du
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Xinan Wang
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Meimei Wang
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Yichen Wang
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Tom K Hei
- Center for Radiological Research, College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA
| | - Lijun Wu
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - An Xu
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, Anhui, China.
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17
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Valério E, Vilares A, Campos A, Pereira P, Vasconcelos V. Effects of microcystin-LR on Saccharomyces cerevisiae growth, oxidative stress and apoptosis. Toxicon 2014; 90:191-8. [DOI: 10.1016/j.toxicon.2014.08.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 08/11/2014] [Accepted: 08/13/2014] [Indexed: 02/04/2023]
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18
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Low in vitro permeability of the cyanotoxin microcystin-LR across a Caco-2 monolayer: with identification of the limiting factors using modelling. Toxicon 2014; 91:5-14. [PMID: 25110175 DOI: 10.1016/j.toxicon.2014.07.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 01/25/2023]
Abstract
Microcystins (MCs) are toxins produced by several cyanobacteria species found worldwide. MC-LR is the most frequent. Here, we used the human Caco-2 cell line grown on semi-permeable filter supports as an in vitro model for determining MC-LR intestinal bidirectional transport. In this study, there was very low and time-dependent apparent permeability of MC-LR. To identify the limiting factors involved in the low permeability of MC-LR, a mathematical model was constructed to get physiologically relevant and informative parameters. The apical-to-basolateral transport was characterised by a rapid and substantial decrease in apical MC-LR concentrations (24-40% of the initial amount). In the basolateral compartment, the concentrations increased slowly after a lag time, but represented only a small fraction of the loaded concentrations (0.3-1.3%) after 24 h. This weak permeability was mainly due to a low clearance of efflux (from the cellular to the basolateral compartment) and effective secretion (from the cellular to the apical compartment). During the basolateral-to-apical transport, we observed a slow decrease in basolateral concentrations and a rapid increase in apical concentrations. In conclusion, modelling has the potential to highlight the key mechanisms involved in the complex kinetics of toxin transport.
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19
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Chen L, Zhang X, Chen J, Zhang X, Fan H, Li S, Xie P. NF-κB plays a key role in microcystin-RR-induced HeLa cell proliferation and apoptosis. Toxicon 2014; 87:120-30. [PMID: 24932741 DOI: 10.1016/j.toxicon.2014.06.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/30/2014] [Accepted: 06/05/2014] [Indexed: 01/26/2023]
Abstract
Microcystins (MCs) are well-known cyanobacterial toxins produced in eutrophic waters and can act as potential carcinogens and have caused serious risk to human health. However, pleiotropic even paradoxical actions of cells exposure to MCs have been reported, and the mechanisms of MC-induced tumorigenesis and apoptosis are still unknown. In this study, we performed the first comprehensive in vitro investigation on carcinogenesis associated with nuclear factor kappa B (NF-κB) and its downstream genes in HeLa cells (Human cervix adenocarcinoma cell line from epithelial cells) exposure to MC-RR. HeLa cells were treated with 0, 20, 40, 60, and 80 µg/mL MC-RR for 4, 8, 12, and 24 h. HeLa cells presented dualistic responses to different doses of MCs. CCK8 assay showed that MC-RR exposure evidently enhanced cell viability of HeLa cells at lower MCs doses. Cell cycle and apoptosis analysis revealed that lower MCs doses promoted G1/S transition and cell proliferation while higher doses of MCs induced apoptosis, with a dose-dependent manner. Electrophoretic mobility shift assay (EMSA) revealed that MC-RR could increase/decrease NF-κB activity at lower/higher MC-RR doses, respectively. Furthermore, the expression of NF-κB downstream target genes including c-FLIP, cyclinD1, c-myc, and c-IAP2 showed the same variation trend as NF-κB activity both at mRNA and protein levels, which were induced by lower doses of MC-RR and suppressed by higher doses. Our data verified for the first time that NF-κB pathway may mediate MC-induced cell proliferation and apoptosis and provided a better understanding of the molecular mechanism for potential carcinogenicity of MC-RR.
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Affiliation(s)
- Liang Chen
- 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
| | - Xin Zhang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jun Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Xuezhen Zhang
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Huihui Fan
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shangchun Li
- 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
| | - Ping Xie
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
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20
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Effects of the amino acid constituents of microcystin variants on cytotoxicity to primary cultured rat hepatocytes. Toxins (Basel) 2013; 6:168-79. [PMID: 24380975 PMCID: PMC3920255 DOI: 10.3390/toxins6010168] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 12/13/2013] [Accepted: 12/24/2013] [Indexed: 12/11/2022] Open
Abstract
Microcystins, which are cyclic heptapeptides produced by some cyanobacterial species from algal blooms, strongly inhibit serine/threonine protein phosphatase and are known as hepatotoxins. Microcystins have many structural variations, yet insufficient information is available on the differences in the cytotoxic potentials among the structural variants. In this study, the cytotoxicities of 16 microcystin variants at concentrations of 0.03–10 μg/mL to primary cultured rat hepatocytes were determined by measuring cellular ATP content, and subsequently determined by their 50% inhibitory concentration (IC50). Differences in the amino acid constituents were associated with differences in cytotoxic potential. [d-Asp3, Z-Dhb7] microcystin-LR exhibited the strongest cytotoxicity at IC50 of 0.053 μg/mL among the microcystin variants tested. Furthermore, [d-Asp3, Z-Dhb7] microcystin-HtyR was also highly cytotoxic. These results suggest that both d-Asp and Z-Dhb residues are important in determining the cytotoxic potential of microcystin variants.
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