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Chen G, Jia Z, Wang L, Hu T. Effect of acute exposure of saxitoxin on development of zebrafish embryos (Danio rerio). ENVIRONMENTAL RESEARCH 2020; 185:109432. [PMID: 32247151 DOI: 10.1016/j.envres.2020.109432] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 03/10/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
As a type of cyanobacterial toxins, saxitoxin (STX) is receiving great interest due to its increasing presence in waterbodies. However, the underlying mechanism of STX-induced adverse effect is poorly understood. Here, we examined the developmental toxicity and molecular mechanism induced by STX using zebrafish embryos as an animal model. The embryonic toxicity induced by STX was demonstrated by inhibition of embryo hatching, increase in mortality rate, abnormal heart rate, abnormalities in embryo morphology as well as defects in angiogenesis and common cardinal vein remodeling. STX induced embryonic DNA damage and cell apoptosis, which would be alleviated by antioxidant N-acetyl-L-cysteine. Additionally, STX significantly increased reactive oxygen species level, catalase activity and malondialdehyde content and decreased the activity of superoxide dismutase and glutathione content. STX also promoted the expression of vascular development-related genes DLL4 and VEGFC, and inhibited VEGFA expression. Furthermore, STX altered the transcriptional regulation of apoptosis-related genes (BAX, BCL-2, P53 and CASPASE 3). Taken together, STX induced adverse effect on development of zebrafish embryos, which might be associated with oxidative stress-induced apoptosis.
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Affiliation(s)
- Guoliang Chen
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China
| | - Zimu Jia
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China
| | - Linping Wang
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China
| | - Tingzhang Hu
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China.
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Wang Q, Liu Y, Guo J, Lin S, Wang Y, Yin T, Gregersen H, Hu T, Wang G. Microcystin-LR induces angiodysplasia and vascular dysfunction through promoting cell apoptosis by the mitochondrial signaling pathway. CHEMOSPHERE 2019; 218:438-448. [PMID: 30485828 DOI: 10.1016/j.chemosphere.2018.11.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/25/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
The harmful algal blooms are becoming increasingly problematic in the regions that drinking water production depends on surface waters. With a global occurrence, microcystins are toxic peptides produced by multiple cyanobacterial genera in the harmful algal blooms. In this study, we examined the effects of microcystin-LR (MC-LR), a representative toxin of the microcystin family, on vascular development in zebrafish and the apoptosis of human umbilical vein endothelial cells (HUVECs). In zebrafish larvae, MC-LR induced angiodysplasia, damaged vascular structures and reduced lumen size at 0.1 μM and 1 μM, leading to the decrease of the blood flow area in the blood vessels and brain hemorrhage, which showed that MC-LR could dose-dependently inhibit vascular development and cause vascular dysfunction. In MC-LR treated HUVECs, the proportion of early apoptosis and late apoptosis cells increased in a concentration-dependent manner. Different concentrations of MC-LR could also activate caspase 3/9 in HUVECs, increase the level of mitochondrial ROS and reduce mitochondrial membrane potential. Additionally, MC-LR could promote the expression of p53 and inhibit the expression of PCNA. The findings showed that MC-LR could promote apoptosis of HUVECs through the mitochondrial signaling pathway. Combined with these results, MC-LR may promote vascular endothelial cell apoptosis through mitochondrial signaling pathway, leading to angiodysplasia and vascular dysfunction.
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Affiliation(s)
- Qilong Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Yuanli Liu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Jingsong Guo
- Key Laboratory of the Three Gorges Reservoir's Eco-Environments of MOE, Chongqing University, Chongqing 400045, China
| | - Song Lin
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Yeqi Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Tieying Yin
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Hans Gregersen
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China
| | - Tingzhang Hu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China.
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education (Chongqing University), State and Local Joint Engineering Laboratory for Vascular Implants (Chongqing), Bioengineering College of Chongqing University, Chongqing 400030, China.
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Ren Y, Yang M, Ma R, Gong Y, Zou Y, Wang T, Wu J. Microcystin-LR promotes migration via the cooperation between microRNA-221/PTEN and STAT3 signal pathway in colon cancer cell line DLD-1. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 167:107-113. [PMID: 30312888 DOI: 10.1016/j.ecoenv.2018.09.065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 08/14/2018] [Accepted: 09/15/2018] [Indexed: 06/08/2023]
Abstract
Previous researches have reported that microcystin-LR (MC-LR) contributes to the progression of multiple types of carcinomas including colon cancer; however, the underlying molecular mechanisms remain unclear and require in-depth investigation. Here, the colon cell line DLD-1 was arranged for the analysis by the microRNA microarray which was associated with the cancer metastasis after MC-LR exposure. 31 human microRNAs were differentially expressed, including miR-221, which targeted 3'-UTR of PTEN mRNA and PTEN level was down-regulated by MC-LR treatment. Besides, MC-LR also induced the phosphorylation of STAT3, which can be reversed by adding miR-221 inhibitor and PTEN expression plasmid. Furthermore, miR-221 inhibitor, STAT3 siRNA and PTEN expression plasmid could reverse the effects of MC-LR induced migration with the accumulation of β-catenin in nuclei. In conclusion, our study suggested that MC-LR promoted the progression of colon carcinoma, at least in part, by regulating the expression miR-221, PTEN and STAT3 phosphorylation, which offers a novel perspective to understand the connection between MC-LR and colon cancer.
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Affiliation(s)
- Yan Ren
- Department of Cell Biology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Mengli Yang
- Department of Cell Biology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Rong Ma
- Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research & The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, China
| | - Ying Gong
- Department of Pharmacy, The Fourth People's Hospital of Jinan City, Jinan, China
| | - Yuntao Zou
- Department of Intensive Care Unit, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Ting Wang
- Department of Cell Biology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China.
| | - Jianzhong Wu
- Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research & The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, China.
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Ma J, Li Y, Duan H, Sivakumar R, Li X. Chronic exposure of nanomolar MC-LR caused oxidative stress and inflammatory responses in HepG2 cells. CHEMOSPHERE 2018; 192:305-317. [PMID: 29117589 DOI: 10.1016/j.chemosphere.2017.10.158] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/26/2017] [Accepted: 10/27/2017] [Indexed: 06/07/2023]
Abstract
Low dose but long-term exposure of microcystin-LR (MC-LR) could induce human hepatitis and promote liver cancer according to epidemiological investigation results, but the exact mechanism has not been completely elucidated. In the present study, a chronic toxicity test of MC-LR exposure on HepG2 cells at 0.1-30 nM for 83 d was conducted under laboratory conditions. The western blot assay result revealed that MC-LR entered HepG2 cells, even at the concentration of 0.1 nM, after 83 d of exposure, but no cytotoxicity was observed in the HepG2 cells, as determined by the CCK-8 and LDH tests. However, the results of the DCF fluorescence assay showed that the intracellular ROS level in the 30 nM MC-LR-treated cells was significantly higher than that of the control cells, and 5 and 10 nM of MC-LR exposure totally increased the activity of SOD in HepG2 cells. These results indicate that MC-LR exposure at low concentration also induced excessive ROS in HepG2 cells. Additionally, long-term exposure of MC-LR at low concentration remarkably promoted the expression of NF-κB p65, COX-2, iNOS, TNF-α, IL-1β, and IL-6 in the cells, suggesting that long-term MC-LR exposure at low concentration can induce inflammatory reaction to HepG2 cells, which might account for MC-induced human hepatitis. Thus, we hypothesized that the pathogenesis of human hepatitis and hepatocarcinoma caused by MCs might be closely associated with oxidative stress and inflammation.
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Affiliation(s)
- Junguo Ma
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yuanyuan Li
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | - Hongying Duan
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | | | - Xiaoyu Li
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China.
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Ma J, Feng Y, Jiang S, Li X. Altered cellular metabolism of HepG2 cells caused by microcystin-LR. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 225:610-619. [PMID: 28336091 DOI: 10.1016/j.envpol.2017.03.029] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/20/2017] [Accepted: 03/14/2017] [Indexed: 06/06/2023]
Abstract
This study aimed to evaluate the possible effects of microcystin-LR (MC-LR) exposure on the metabolism and drug resistance of human hepatocellular carcinoma (HepG2) cells. For this purpose, we first conducted an experiment to make sure that MC-LR could penetrate the HepG2 cell membrane effectively. The transcriptional levels of phase I (such as CYP2E1, CYP3A4, and CYP26B1) and phase II (such as EPHX1, SULTs, and GSTM) enzymes and export pump genes (such as MRP1 and MDR1) were altered by MC-LR-exposure for 24 h, indicating that MC-LR treatment may destabilize the metabolism of HepG2 cells. Further research showed that the CYP inducers omeprazole, ethanol, and rifampicin inhibited cell viability, in particular, ethanol, a CYP2E1 inducer, induced ROS generation, lipid peroxidation, and apoptosis in HepG2 cells treated with MC-LR. The CYP2E1 inhibitor chlormethiazole inhibited ROS generation, mitochondrial membrane potential loss, caspase-3 activity, and cytotoxicity caused by MC-LR. Meanwhile, the results also showed that co-incubation with the ROS scavenger l-ascorbic acid and MC-LR decreased ROS levels and effectively prevented apoptosis. These findings provide an interesting mechanistic explanation of cellular metabolism associated with MC-LR, i.e., MC-LR-exposure exerted toxicity on HepG2 cells and induced apoptosis of HepG2 cells via promoting CYP2E1 expression and inducing excessive ROS in HepG2 cells.
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Affiliation(s)
- Junguo Ma
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yiyi Feng
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | - Siyu Jiang
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | - Xiaoyu Li
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China.
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Water metabolism dysfunction via renin-angiotensin system activation caused by liver damage in mice treated with microcystin-RR. Toxicol Lett 2017; 273:86-96. [PMID: 28330766 DOI: 10.1016/j.toxlet.2017.03.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 03/10/2017] [Accepted: 03/17/2017] [Indexed: 01/12/2023]
Abstract
Microcystins (MCs) are a group of monocyclic heptapeptide toxins that have been shown to act as potent hepatotoxins. However, the observed symptoms of water metabolism disruption induced by microcystin-RR (MC-RR) or MCs have rarely been reported, and a relatively clear mechanism has not been identified. In the present study, male mice were divided into 4 groups (A: 140μg/kg, B: 70μg/kg,C: 35μg/kg, and D: 0μg/kg) and administered MC-RR daily for a month. On day 8 of treatment, an increase in water intake and urine output was observed in the high-dose group compared with the control, and the symptoms worsened with the repeated administration of the toxin until day 30. In addition, the urine specific gravity decreased and serum enzymes that can reflect hepatic damage increased in the high-dose group compared with the control (P<0.05). The mRNA level of angiotensinogen (AGT) in hepatocytes was upregulated to approximately 150% of the control (P<0.05), and the serum renin-angiotensin system (RAS) was activated in the high-dose group; however, signs of renal injury were not observed throughout the experiment. After the toxin treatment was completed, the high levels of the RAS and vasopressin in group A returned to normal levels within 1 week. As expected, the symptoms of polyuria and polydipsia also disappeared. Therefore, we propose that water metabolism dysfunction occurs via RAS activation caused by liver damage because the increased serum RAS levels in the experiment were consistent with the increased urine output and water intake in the mice during the observation period. In addition, we found for the first time that a RAS blocker could alleviate the observed polyuria and polydipsia and inactivate the high level of the RAS induced by MC-RR in a dose-dependent manner, which further supported our hypothesis.
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Wang B, Liu J, Huang P, Xu K, Wang H, Wang X, Guo Z, Xu L. Protein phosphatase 2A inhibition and subsequent cytoskeleton reorganization contributes to cell migration caused by microcystin-LR in human laryngeal epithelial cells (Hep-2). ENVIRONMENTAL TOXICOLOGY 2017; 32:890-903. [PMID: 27393157 DOI: 10.1002/tox.22289] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 05/08/2016] [Accepted: 05/08/2016] [Indexed: 06/06/2023]
Abstract
The major toxic mechanism of Microcystin-LR is inhibition of the activity of protein phosphatase 2A (PP2A), resulting in a series of cytotoxic effects. Our previous studies have demonstrated that microcystin-LR (MCLR) induced very different molecular effects in normal cells and the tumor cell line SMMC7721. To further explore the MCLR toxicity mechanism in tumor cells, human laryngeal epithelial cells (Hep-2) was examined in this study. Western blot, immunofluorescence, immunoprecipitation, and transwell migration assay were used to detect the effects of MCLR on PP2A activity, PP2A substrates, cytoskeleton, and cell migration. The results showed that the protein level of PP2A subunits and the posttranslational modification of the catalytic subunit were altered and that the binding of the AC core enzyme as well as the binding of PP2A/C and α4, was also affected. As PP2A substrates, the phosphorylation of MAPK pathway members, p38, ERK1/2, and the cytoskeleton-associated proteins, Hsp27, VASP, Tau, and Ezrin were increased. Furthermore, MCLR induced reorganization of the cytoskeleton and promoted cell migration. Taken together, direct covalent binding to PP2A/C, alteration of the protein levels and posttranslational modification, as well as the binding of subunits, are the main pattern for the effects of MCLR on PP2A in Hep-2. A dose-dependent change in p-Tau and p-Ezrin due to PP2A inhibition may contribute to the changes in the cytoskeleton and be related to the cell migration in Hep-2. Our data provide a comprehensive exposition of the MCLR mechanism on tumor cells. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 890-903, 2017.
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Affiliation(s)
- Beilei Wang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Jinghui Liu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Pu Huang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Kailun Xu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Hanying Wang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Xiaofeng Wang
- Zhejiang Center for Disease Control and Prevention, Hangzhou, 310051, China
| | - Zonglou Guo
- Department of Biosystem Engineering, College of Biosystem Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Lihong Xu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
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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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Ma J, Feng Y, Liu Y, Li X. PUMA and survivin are involved in the apoptosis of HepG2 cells induced by microcystin-LR via mitochondria-mediated pathway. CHEMOSPHERE 2016; 157:241-249. [PMID: 27235693 DOI: 10.1016/j.chemosphere.2016.05.051] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/04/2016] [Accepted: 05/17/2016] [Indexed: 06/05/2023]
Abstract
The present study aimed to determine the cytotoxicity of microcystin-LR (MC-LR) on the human hepatocellular carcinoma (HepG2) cells in order to elucidate the mechanism of apoptosis induced by MC-LR. Morphological evaluation results showed that MC-LR induced time- and concentration-dependent apoptosis in HepG2 cells. The biochemical assays revealed that MC-LR-exposure caused overproduction of reactive oxygen species (ROS), cyclooxygenase-2 activity alteration, cytochrome c release, and remarkable activation of caspase-3 and caspase-9 in HepG2 cells, indicating that MC-LR-induced apoptosis is mediated by mitochondrial pathway. Moreover, we also found that p53 and Bax might play an important role in MC-LR-induced apoptosis in HepG2 cells in which PUMA and survivin were involved. However, further studies are necessary to elucidate the possible functions of PUMA and survivin in MC-LR-induced apoptosis in HepG2 cells.
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Affiliation(s)
- Junguo Ma
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yiyi Feng
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yang Liu
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China
| | - Xiaoyu Li
- College of Life Science, Henan Normal University, Xinxiang, Henan 453007, China.
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Qi M, Dang Y, Xu Q, Yu L, Liu C, Yuan Y, Wang J. Microcystin-LR induced developmental toxicity and apoptosis in zebrafish (Danio rerio) larvae by activation of ER stress response. CHEMOSPHERE 2016; 157:166-173. [PMID: 27219292 DOI: 10.1016/j.chemosphere.2016.05.038] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/12/2016] [Accepted: 05/12/2016] [Indexed: 06/05/2023]
Abstract
Recent studies have demonstrated that cyanobacteria-derived Microcystin-LR (MC-LR) can cause developmental toxicity and trigger apoptosis in zebrafish (Danio rerio) larvae, but the underlying mechanisms remain largely unknown. In this study, we tested the hypothesis that the mechanism by which MC-LR induces developmental toxicity is through activation of endoplasmic reticulum (ER) stress. MC-LR (4.0 μM) exposure through submersion caused serious developmental toxicity, such as malformation, growth delay and decreased heart rates in zebrafish larvae, which could be inhibited by ER stress blocker, tauroursodeoxycholic acid (TUDCA, 20 μM). Meanwhile, acridine orange (AO) staining showed TUDCA could rescue cell apoptosis in heart area in zebrafish larvae resulted by MC-LR exposure. Real-time polymerase chain reaction (real-time PCR) analysis demonstrated that MC-LR induced activation of ER stress which consequently triggered apoptosis in zebrafish larvae. Protein expression examined by western blot indicated that MC-LR could activate MAPK8/Bcl-2/Bax pathway and caspase-dependent apoptotic pathway in zebrafish larva and the effects were mitigated by inhibition of ER stress. Taken together, the results observed in this study suggested that ER stress plays a critical role in developmental toxicity and apoptosis in zebrafish embryos exposed to MC-LR.
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Affiliation(s)
- Mei Qi
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Yao Dang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Qinglong Xu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Liqin Yu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, China
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, China; Collaborative Innovation Center for Efficient and Health Production of Fisheries in Hunan Province, Changde 415000, China
| | - Yongchao Yuan
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Jianghua Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, China.
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Chen L, Chen J, Zhang X, Xie P. A review of reproductive toxicity of microcystins. JOURNAL OF HAZARDOUS MATERIALS 2016; 301:381-99. [PMID: 26521084 DOI: 10.1016/j.jhazmat.2015.08.041] [Citation(s) in RCA: 233] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Revised: 08/20/2015] [Accepted: 08/23/2015] [Indexed: 05/25/2023]
Abstract
Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies.
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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.
| | - 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
- College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, 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.
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Cai F, Liu J, Li C, Wang J. Critical Role of Endoplasmic Reticulum Stress in Cognitive Impairment Induced by Microcystin-LR. Int J Mol Sci 2015; 16:28077-86. [PMID: 26602924 PMCID: PMC4691030 DOI: 10.3390/ijms161226083] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 01/11/2023] Open
Abstract
Recent studies showed that cyanobacteria-derived microcystin-leucine-arginine (MCLR) can cause hippocampal pathological damage and trigger cognitive impairment; but the underlying mechanisms have not been well understood. The objective of the present study was to investigate the mechanism of MCLR-induced cognitive deficit; with a focus on endoplasmic reticulum (ER) stress. The Morris water maze test and electrophysiological study demonstrated that MCLR caused spatial memory injury in male Wistar rats; which could be inhibited by ER stress blocker; tauroursodeoxycholic acid (TUDCA). Meanwhile; real-time polymerase chain reaction (real-time PCR) and immunohistochemistry demonstrated that the expression level of the 78-kDa glucose-regulated protein (GRP78); C/EBP homologous protein (CHOP) and caspase 12 were significantly up-regulated. These effects were rescued by co-administration of TUDCA. In agreement with this; we also observed that treatment of rats with TUDCA blocked the alterations in ER ultrastructure and apoptotic cell death in CA1 neurons from rats exposed to MCLR. Taken together; the present results suggested that ER stress plays an important role in potential memory impairments in rats treated with MCLR; and amelioration of ER stress may serve as a novel strategy to alleviate damaged cognitive function triggered by MCLR.
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Affiliation(s)
- Fei Cai
- Department of Pharmacology, Hubei University of Science and Technology, Xianning 437100, China.
| | - Jue Liu
- Department of Pharmacy, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430014, China.
| | - Cairong Li
- Hubei Province Key Laboratory on Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning 437100, China.
| | - Jianghua Wang
- Fisheries College, Huazhong Agricultural University, Wuhan 430070, China.
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Mechanisms of microcystin-LR-induced cytoskeletal disruption in animal cells. Toxicon 2015; 101:92-100. [DOI: 10.1016/j.toxicon.2015.05.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 05/06/2015] [Accepted: 05/12/2015] [Indexed: 12/31/2022]
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14
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Ma J, Feng Y, Xie W, Li X. PP2A (PR65) in Silver Carp: cDNA Cloning and Expression Analysis. J Biochem Mol Toxicol 2015; 29:399-409. [DOI: 10.1002/jbt.21706] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 02/07/2015] [Accepted: 03/01/2015] [Indexed: 12/27/2022]
Affiliation(s)
- Junguo Ma
- College of Life Science; Henan Normal University; Xinxiang Henan 453007 China
| | - Yiyi Feng
- College of Life Science; Henan Normal University; Xinxiang Henan 453007 China
| | - Wenjie Xie
- College of Life Science; Henan Normal University; Xinxiang Henan 453007 China
| | - Xiaoyu Li
- College of Life Science; Henan Normal University; Xinxiang Henan 453007 China
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15
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Zhang H, Cai C, Fang W, Wang J, Zhang Y, Liu J, Jia X. Oxidative damage and apoptosis induced by microcystin-LR in the liver of Rana nigromaculata in vivo. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 140-141:11-18. [PMID: 23747548 DOI: 10.1016/j.aquatox.2013.05.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 05/11/2013] [Accepted: 05/13/2013] [Indexed: 06/02/2023]
Abstract
Microcystins (MCs) are hepatotoxins with potent inhibitor activity of protein phosphatases PP1 and PP2A. The present study shows that MC-LR can induce severe oxidative damage and apoptosis in the livers of frogs (Rana nigromaculata) exposed to 1μg/L MC-LR for 7 and 14d in vivo. Ultrastructural observation showed the apoptotic morphology of perinuclear chromatin margination and swollen mitochondria, indicating that MC-LR can significantly damage frog liver. Reactive oxygen species (ROS) production and malondialdehyde (MDA) content were positively correlated with exposure time. Meanwhile, reduced glutathione (GSH) content and GSH peroxidase (GPx) activity rapidly decreased after prolonged exposure to 1μg/L MC-LR in a time-dependent manner. These results imply that the antioxidant defense systems of the liver were damaged. Enhanced apoptosis of cells in the livers of MC-treated frogs was detected by terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling (TUNEL) associated with up-regulation of the mitochondrial system. MC-LR significantly stimulated the livers to release cytochrome c, which improved the protein expressions of Bax, caspase-3, and caspase-9 (p<0.01) and inhibited the protein expression of Bcl-2 with prolonged exposure (p<0.01) via the mitochondrial pathway. These results imply that the mitochondrial pathway has a key function in toxin-induced liver cell apoptosis. The expression of caspase-8 was induced significantly (p<0.01), which illustrates the mechanism that the death receptor pathway is also involved in apoptosis. The present findings show that MC-LR can induce apoptosis in frog liver, which may be related with the decline of amphibian populations. The World Health Organization-recommended drinking water limit for MC-LR in water may be not safe for amphibians.
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Affiliation(s)
- Hangjun Zhang
- Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16#, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province 310036, China
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16
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Zhang H, Cai C, Wu Y, Shao D, Ye B, Zhang Y, Liu J, Wang J, Jia X. Mitochondrial and endoplasmic reticulum pathways involved in microcystin-LR-induced apoptosis of the testes of male frog (Rana nigromaculata) in vivo. JOURNAL OF HAZARDOUS MATERIALS 2013; 252-253:382-389. [PMID: 23548922 DOI: 10.1016/j.jhazmat.2013.03.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/07/2013] [Accepted: 03/08/2013] [Indexed: 06/02/2023]
Abstract
Previous studies have shown that toxins produced by toxic cyanobacterial blooms are hazardous materials. In the present study, 1 μg/L microcystin-LR (MC-LR) was observed to induce apoptosis in the testes of male Rana nigromaculata via the mitochondrial and endoplasmic reticulum (ER) pathways at exposure times ranging from 7 d to 14 d. The results showed that reactive oxygen species production and malondialdehyde content were positively correlated with exposure time. Antioxidant enzyme contents, such as reduced glutathione and glutathione peroxidase rapidly decreased, implying that the defense system of the testes induces oxidative damage. MC-LR significantly stimulated the release of cytochrome c in the testes, thereby improving the protein expressions of Bax and caspases-3, 8, and 9 (p<0.01) and inhibiting the protein expression of Bcl-2 with prolonged exposure (p<0.01). Ultrastructural observations showed distention of the mitochondria and endoplasmic reticulum and deformation of the nucleolus. Moreover, prolonged exposure times strengthened and weakened the relative expression levels of C/EBP homologous protein and GRP78, respectively. These results indicate that MC-LR-induced apoptosis of the testes in male frogs in vivo may occur through the mitochondrial and ER pathways. It also further proves our previous findings that MC-LR can induce toxicity in the male reproductive system of R. nigromaculata in vitro. The findings show that MC-LR is highly hazardous to frogs and that the accepted drinking water limit of 1 μg/L MC-LR exerts significant toxicity to amphibians.
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Affiliation(s)
- Hangjun Zhang
- Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16#, Xiasha Gaojiao Dongqu, Hangzhou, Zhejiang Province 310036, China
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17
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Li T, Ying L, Wang H, Li N, Fu W, Guo Z, Xu L. Microcystin-LR Induces Ceramide to Regulate PP2A and Destabilize Cytoskeleton in HEK293 Cells. Toxicol Sci 2012; 128:147-57. [DOI: 10.1093/toxsci/kfs141] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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18
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Liang J, Li T, Zhang YL, Guo ZL, Xu LH. Effect of microcystin-LR on protein phosphatase 2A and its function in human amniotic epithelial cells. J Zhejiang Univ Sci B 2012; 12:951-60. [PMID: 22135143 DOI: 10.1631/jzus.b1100121] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Due to their toxicity, the increased distribution of microcystins (MCs) has become an important worldwide problem. MCs have been recognized as inhibitors of protein phosphatase 2A (PP2A) through their binding to the PP2A catalytic subunit. However, the exact mechanism of MC toxicity has not been elucidated, especially concerning the cellular response and its autoregulation. To further dissect the role of PP2A in MC-induced toxicity, the present study was undertaken to determine the response of PP2A in human amniotic epithelial (FL) cells treated with microcystin-LR (MCLR), one of the MC congeners. The results show that a low-dose treatment of MCLR in FL cells for 6 h induced an increase in PP2A activity, and a high-dose treatment of MCLR for 24 h decreased the activity of PP2A, as expected. The increased mRNA and protein levels of the PP2A C subunit may explain the increased activity of PP2A. Furthermore, MCLR altered microtubule post-translational modifications through PP2A. These results further clarify the underlying mechanism how MCLR affects PP2A and may be helpful for elucidating the complex toxicity of MCLR.
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Affiliation(s)
- Jing Liang
- Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou, China
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19
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Meng G, Sun Y, Fu W, Guo Z, Xu L. Microcystin-LR induces cytoskeleton system reorganization through hyperphosphorylation of tau and HSP27 via PP2A inhibition and subsequent activation of the p38 MAPK signaling pathway in neuroendocrine (PC12) cells. Toxicology 2011; 290:218-29. [DOI: 10.1016/j.tox.2011.09.085] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Revised: 09/23/2011] [Accepted: 09/28/2011] [Indexed: 11/16/2022]
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20
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Huang P, Zheng Q, Xu LH. The apoptotic effect of oral administration of microcystin-RR on mice liver. ENVIRONMENTAL TOXICOLOGY 2011; 26:443-452. [PMID: 20196164 DOI: 10.1002/tox.20570] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 01/04/2010] [Accepted: 01/11/2010] [Indexed: 05/28/2023]
Abstract
Microcystin produced by cyanobacteria in diverse water systems is a potent hepatotoxin that has been documented to induce hepatocyte apoptosis and liver injury. There are more than eighty reported microcystins. The present work aimed at investigating the apoptotic effect of MC-RR (a common member of microcystin family), and its related mechanism. MC-RR was administered orally to ICR mice for 7 days with different dosages. Apoptotic cell death in liver was detected by TUNEL assay, and the expression levels of Bcl-2, Bax and p53, GRP 78 and CHOP which have been reported to be related to apoptosis and ER stress were determined via western-blot. The activity of PP2A was measured using the serine-threonine phosphatase assay system and PP2A A subunit expression at both transcription and protein levels was measured by RT-PCR and western blot, respectively. A significant difference was observed on the number of TUNEL positive liver cells between the control and MC-RR-treated groups. The expression levels of Bcl-2, Bax, p53, and GRP 78 in MC-RR-treated groups were altered significantly compared to the control, but no obvious alteration was found in CHOP expression. The PP2A activity and A subunit expression did not manifest any obvious change at both transcription and protein levels. The results indicated that oral exposure to MC-RR can cause apoptosis as well as moderate ER stress in mice liver. The mitochondrial pathway via Bcl-2 family members may contribute to the apoptosis. However, PP2A may not be involved in the regulation of apoptotic process under the current conditions.
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Affiliation(s)
- Pu Huang
- Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058, China
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21
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Li T, Huang P, Liang J, Fu W, Guo Z, Xu L. Microcystin-LR (MCLR) induces a compensation of PP2A activity mediated by α4 protein in HEK293 cells. Int J Biol Sci 2011; 7:740-52. [PMID: 21698000 PMCID: PMC3119846 DOI: 10.7150/ijbs.7.740] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 05/30/2011] [Indexed: 01/14/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a major protein phosphatase with important cell functions. Known and utilized as a potent inhibitor of PP2A, microcystin-LR (MCLR) targets PP2A as a core element that affects numerous cellular mechanisms. But apart from direct inhibition, the exact effect of MCLR on PP2A in cell is largely unknown, specifically with regard to cellular response and autoregulation. Here, we show that a low concentration of MCLR stimulates, rather than inhibits, PP2A activity in HEK293 cells. Immunoprecipitation and immunofluorescence assays reveal that the catalytic subunit and a regulatory subunit of PP2A, termed α4, dissociate from inactive complex upon MCLR exposure, suggesting that the released catalytic subunit regains activity and thereby compensates the activity loss. At high concentrations of MCLR, PP2A activity decreases along with dissociation of the core enzyme and altered post-translational modification of its catalytic subunit. In addition, the dissociation of α4 and PP2A may contribute to destabilization of HEK293 cells cytoskeleton architecture, detachment to extracellular matrix and further anoikis. Our data provide a novel PP2A upregulation mechanism and challenge the recognition of MCLR only as a PP2A inhibitor in cells.
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Affiliation(s)
- Tan Li
- Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou, China
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22
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Shi Y, Guo C, Sun Y, Liu Z, Xu F, Zhang Y, Wen Z, Li Z. Interaction between DNA and Microcystin-LR Studied by Spectra Analysis and Atomic Force Microscopy. Biomacromolecules 2011; 12:797-803. [DOI: 10.1021/bm101414w] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yan Shi
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China
| | - Cunlan Guo
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China
| | - Yujing Sun
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China
| | - Zhelin Liu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China
| | - Fugang Xu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China
| | - Yue Zhang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China
| | - Zhiwei Wen
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China
| | - Zhuang Li
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, People’s Republic of China, and Graduate School of the Chinese Academy of Sciences, Beijing, 100039, People’s Republic of China
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Qin W, Xu L, Zhang X, Wang Y, Meng X, Miao A, Yang L. Endoplasmic reticulum stress in murine liver and kidney exposed to microcystin-LR. Toxicon 2010; 56:1334-41. [DOI: 10.1016/j.toxicon.2010.07.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Revised: 07/08/2010] [Accepted: 07/22/2010] [Indexed: 11/24/2022]
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24
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Campos A, Vasconcelos V. Molecular mechanisms of microcystin toxicity in animal cells. Int J Mol Sci 2010; 11:268-287. [PMID: 20162015 PMCID: PMC2821003 DOI: 10.3390/ijms11010268] [Citation(s) in RCA: 347] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/11/2010] [Accepted: 01/12/2010] [Indexed: 12/31/2022] Open
Abstract
Microcystins (MC) are potent hepatotoxins produced by the cyanobacteria of the genera Planktothrix, Microcystis, Aphanizomenon, Nostoc and Anabaena. These cyclic heptapeptides have strong affinity to serine/threonine protein phosphatases (PPs) thereby acting as an inhibitor of this group of enzymes. Through this interaction a cascade of events responsible for the MC cytotoxic and genotoxic effects in animal cells may take place. Moreover MC induces oxidative stress in animal cells and together with the inhibition of PPs, this pathway is considered to be one of the main mechanisms of MC toxicity. In recent years new insights on the key enzymes involved in the signal-transduction and toxicity have been reported demonstrating the complexity of the interaction of these toxins with animal cells. Key proteins involved in MC up-take, biotransformation and excretion have been identified, demonstrating the ability of aquatic animals to metabolize and excrete the toxin. MC have shown to interact with the mitochondria. The consequences are the dysfunction of the organelle, induction of reactive oxygen species (ROS) and cell apoptosis. MC activity leads to the differential expression/activity of transcriptional factors and protein kinases involved in the pathways of cellular differentiation, proliferation and tumor promotion activity. This activity may result from the direct inhibition of the protein phosphatases PP1 and PP2A. This review aims to summarize the increasing data regarding the molecular mechanisms of MC toxicity in animal systems, reporting for direct MC interacting proteins and key enzymes in the process of toxicity biotransformation/excretion of these cyclic peptides.
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Affiliation(s)
- Alexandre Campos
- Centro Interdisciplinar de Investigação Marinha e Ambiental, CIIMAR/CIMAR, Rua dos Bragas 289, 4050-123 Porto, Portugal; E-Mail:
- Author to whom correspondence should be addressed; E-Mail:
; Tel.: +351-223-401-813; Fax: +351-223-390-608
| | - Vitor Vasconcelos
- Centro Interdisciplinar de Investigação Marinha e Ambiental, CIIMAR/CIMAR, Rua dos Bragas 289, 4050-123 Porto, Portugal; E-Mail:
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4069-007 Porto, Portugal
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Xing ML, Wang XF, Zhu X, Zhou XD, Xu LH. Morphological and biochemical changes associated with apoptosis induced by okadaic acid in human amniotic FL cells. ENVIRONMENTAL TOXICOLOGY 2009; 24:437-445. [PMID: 18937299 DOI: 10.1002/tox.20446] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The marine toxin okadaic acid (OA) is an apoptosis inducer and a tumor promoter. During recent years, extensive studies have demonstrated that OA can induce apoptosis in a wide variety of cell types. In contrast to the relatively longer incubation time or higher treatment concentrations of OA in apoptosis shown previously, relatively lower concentrations (<or=100 nM) and shorter time (4 h) were designed in the current study to observe the toxic effects of OA in human amniotic cells (FL cells). The present study was undertaken to determine the morphological and biochemical changes of FL cells induced by OA. Results indicated that externalization of phosphatidylserine, cytoskeletal disruption, DNA strand breaks and decrease of Bcl-2 protein expression levels as well as increase of PP2A-A subunit protein were all involved in the apoptosis of FL cells induced by OA. This work not only provided further evidence of apoptosis induced by OA but also suggested that PP2A might play a pivotal role in apoptosis induced by protein phosphatases inhibitors.
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Affiliation(s)
- Ming-luan Xing
- Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058, China
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26
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Zhao Y, Xie P, Tang R, Zhang X, Li L, Li D. In vivo studies on the toxic effects of microcystins on mitochondrial electron transport chain and ion regulation in liver and heart of rabbit. Comp Biochem Physiol C Toxicol Pharmacol 2008; 148:204-10. [PMID: 18590982 DOI: 10.1016/j.cbpc.2008.05.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2008] [Revised: 05/19/2008] [Accepted: 05/20/2008] [Indexed: 11/24/2022]
Abstract
This study examined the toxic effects of microcystins on mitochondria of liver and heart of rabbit in vivo. Rabbits were injected i.p. with extracted microcystins (mainly MC-RR and -LR) at two doses, 12.5 and 50 MC-LReq. microg/kg bw, and the changes in mitochondria of liver and heart were studied at 1, 3, 12, 24 and 48 h after injection. MCs induced damage of mitochondrial morphology and lipid peroxidation in both liver and heart. MCs influenced respiratory activity through inhibiting NADH dehydrogenase and enhancing succinate dehydrogenase (SDH). MCs altered Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities of mitochondria and consequently disrupted ionic homeostasis, which might be partly responsible for the loss of mitochondrial membrane potential (MMP). MCs were highly toxic to mitochondria with more serious damage in liver than in heart. Damage of mitochondria showed reduction at 48 h in the low dose group, suggesting that the low dose of MCs might have stimulated a compensatory response in the rabbits.
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Affiliation(s)
- Yanyan Zhao
- Fisheries College of Huazhong Agricultural University; Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Wuhan 430070, People's Republic of China
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