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Liu Z, Zhang Y, Jia X, Hoskins TD, Lu L, Han Y, Zhang X, Lin H, Shen L, Feng Y, Zheng Y, Hu C, Zhang H. Microcystin-LR Induces Estrogenic Effects at Environmentally Relevant Concentration in Black-Spotted Pond Frogs ( Pelophylax nigromaculatus): In Situ, In Vivo, In Vitro, and In Silico Investigations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:9559-9569. [PMID: 38710655 DOI: 10.1021/acs.est.4c01322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Harmful cyanobacterial blooms are frequent and intense worldwide, creating hazards for aquatic biodiversity. The potential estrogen-like effect of Microcystin-LR (MC-LR) is a growing concern. In this study, we assessed the estrogenic potency of MC-LR in black-spotted frogs through combined field and laboratory approaches. In 13 bloom areas of Zhejiang province, China, the MC-LR concentrations in water ranged from 0.87 to 8.77 μg/L and were correlated with sex hormone profiles in frogs, suggesting possible estrogenic activity of MC-LR. Tadpoles exposed to 1 μg/L, an environmentally relevant concentration, displayed a female-biased sex ratio relative to controls. Transcriptomic results revealed that MC-LR induces numerous and complex effects on gene expression across multiple endocrine axes. In addition, exposure of male adults significantly increased the estradiol (E2)/testosterone (T) ratio by 3.5-fold relative to controls. Downregulation of genes related to male reproductive endocrine function was also identified. We also showed how MC-LR enhances the expression of specific estrogen receptor (ER) proteins, which induce estrogenic effects by activating the ER pathway and hypothalamic-pituitary-gonadal (HPG) axis. In aggregate, our results reveal multiple lines of evidence demonstrating that, for amphibians, MC-LR is an estrogenic endocrine disruptor at environmentally relevant concentrations. The data presented here support the need for a shift in the MC-LR risk assessment. While hepatoxicity has historically been the focus of MC-LR risk assessments, our data clearly demonstrate that estrogenicity is a major mode of toxicity at environmental levels and that estrogenic effects should be considered for risk assessments on MC-LR going forward.
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Affiliation(s)
- Zhiquan Liu
- School of Engineering, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yinan Zhang
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Xiuying Jia
- Hangzhou City University, Hangzhou, Zhejiang 310015, China
| | - Tyler D Hoskins
- Department of Forestry & Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Liping Lu
- School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yu Han
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Xiaofang Zhang
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Huikang Lin
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Lilai Shen
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yixuan Feng
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Yueyue Zheng
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Chao Hu
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
| | - Hangjun Zhang
- School of Engineering, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
- Hangzhou International Urbanology Research Center, Hangzhou 311121, China
- School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China
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Ge K, Du X, Liu H, Meng R, Wu C, Zhang Z, Liang X, Yang J, Zhang H. The cytotoxicity of microcystin-LR: ultrastructural and functional damage of cells. Arch Toxicol 2024; 98:663-687. [PMID: 38252150 DOI: 10.1007/s00204-023-03676-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024]
Abstract
Microcystin-LR (MC-LR) is a toxin produced by cyanobacteria, which is widely distributed in eutrophic water bodies and has multi-organ toxicity. Previous cytotoxicity studies have mostly elucidated the effects of MC-LR on intracellular-related factors, proteins, and DNA at the molecular level. However, there have been few studies on the adverse effects of MC-LR on cell ultrastructure and function. Therefore, research on the cytotoxicity of MC-LR in recent years was collected and summarized. It was found that MC-LR can induce a series of cytotoxic effects, including decreased cell viability, induced autophagy, apoptosis and necrosis, altered cell cycle, altered cell morphology, abnormal cell migration and invasion as well as leading to genetic damage. The above cytotoxic effects were related to the damage of various ultrastructure and functions such as cell membranes and mitochondria. Furthermore, MC-LR can disrupt cell ultrastructure and function by inducing oxidative stress and inhibiting protein phosphatase activity. In addition, the combined toxic effects of MC-LR and other environmental pollutants were investigated. This review explored the toxic targets of MC-LR at the subcellular level, which will provide new ideas for the prevention and treatment of multi-organ toxicity caused by MC-LR.
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Affiliation(s)
- Kangfeng Ge
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Xingde Du
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Haohao Liu
- Department of Public Health, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450001, China
| | - Ruiyang Meng
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Chunrui Wu
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Zongxin Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Xiao Liang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Jun Yang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, 450001, China.
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3
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Zhou Y, Xue M, Jiang Y, Zhang M, Wang C, Wang X, Yu G, Tang Z. Beneficial Effects of Quercetin on Microcystin-LR Induced Tight Junction Defects. Front Pharmacol 2021; 12:733993. [PMID: 34566654 PMCID: PMC8462518 DOI: 10.3389/fphar.2021.733993] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/24/2021] [Indexed: 01/22/2023] Open
Abstract
Quercetin has numerous functions including antioxidant and anti-inflammatory effects. The beneficial effect of quercetin against microcystin-LR (MC-LR)-induced testicular tight junctions (TJs) defects in vitro and in vivo were investigated. Significant reductions in transepithelial electrical resistance, occludin, and zonula occludens-1(ZO-1) levels were detected in the MC-LR-treated TM4 cells, and quercetin attenuated these effects. Interestingly, quercetin suppressed MC-LR-induced phosphorylation of protein kinase B (AKT). It effectively inhibited the accumulation of reactive oxygen species (ROS) in cells stimulated by MC-LR. In addition, ROS inhibitors blocked the TJ damage that is dependent on the AKT signaling pathway induced by MC-LR. In conclusion, our results suggest that alleviates MC-LR-impaired TJs by suppressing the ROS-regulated activation of the AKT pathway.
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Affiliation(s)
- Yuan Zhou
- Department of Physiology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Mei Xue
- College of Traditional Chinese Medicine·College of Intergrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yunfei Jiang
- Department of Emergency, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Miaomiao Zhang
- Department of Physiology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Changming Wang
- Department of Physiology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xuyang Wang
- Department of Neurosurgery, Shanghai Jiao Tong University Affiliated 6th People's Hospital, Shanghai, China
| | - Guang Yu
- Department of Physiology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Zongxiang Tang
- Department of Physiology, School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
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Frohner IE, Mudrak I, Schüchner S, Anrather D, Hartl M, Sontag JM, Sontag E, Wadzinski BE, Preglej T, Ellmeier W, Ogris E. PP2A C Phospho-Tyr 307 Antibodies Are Not Specific for this Modification but Are Sensitive to Other PP2A C Modifications Including Leu 309 Methylation. Cell Rep 2021; 30:3171-3182.e6. [PMID: 32130916 DOI: 10.1016/j.celrep.2020.02.035] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/03/2019] [Accepted: 02/07/2020] [Indexed: 02/06/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is an important regulator of signal transduction pathways and a tumor suppressor. Phosphorylation of the PP2A catalytic subunit (PP2AC) at tyrosine 307 has been claimed to inactivate PP2A and was examined in more than 180 studies using commercial antibodies, but this modification was never identified using mass spectrometry. Here we show that the most cited pTyr307 monoclonal antibodies, E155 and F-8, are not specific for phosphorylated Tyr307 but instead are hampered by PP2AC methylation at leucine 309 or phosphorylation at threonine 304. Other pTyr307 antibodies are sensitive to PP2AC methylation as well, and some cross-react with pTyr residues in general, including phosphorylated hemagglutinin tags. We identify pTyr307 using targeted mass spectrometry after transient overexpression of PP2AC and Src kinase. Yet under such conditions, none of the tested antibodies show exclusive pTyr307 specificity. Thus, data generated using these antibodies need to be revisited, and the mechanism of PP2A inactivation needs to be redefined.
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Affiliation(s)
- Ingrid E Frohner
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Ingrid Mudrak
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Stefan Schüchner
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Dorothea Anrather
- Mass Spectrometry Facility, Max Perutz Labs, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Markus Hartl
- Mass Spectrometry Facility, Max Perutz Labs, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Jean-Marie Sontag
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Estelle Sontag
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Brian E Wadzinski
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Teresa Preglej
- Division of Immunobiology, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | - Wilfried Ellmeier
- Division of Immunobiology, Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | - Egon Ogris
- Center for Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria.
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5
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Quan X, Liu X, Qin X, Wang Y, Sun T, Li Z, Zhu L, Chen J, Zhou Y, Singh S, Dong H, Zhang Z, Zhang H. The role of LR-TIMAP/PP1c complex in the occurrence and development of no-reflow. EBioMedicine 2021; 65:103251. [PMID: 33639401 PMCID: PMC7921471 DOI: 10.1016/j.ebiom.2021.103251] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 02/01/2021] [Accepted: 02/03/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The presence of no-reflow can increase the risk of major adverse cardiac events and is widely regarded as an important sign of serious prognosis. Previous studies show that laminin receptor (LR) is closely related to the morphology and function of microvessels. However, whether LR is involved in the occurrence and development of no-reflow is still unknown. METHODS In vivo, positron emission tomography (PET) perfusion imaging was performed to detect the effects of intramyocardial gene (LR-AAV and LR-siRNA-AAV) delivery treatment on the degree of no-reflow. In vitro, LC-MS/MS analysis was conducted to identify the LR phosphorylation sites of human cardiac microvascular endothelial cells (HCMECs) treated with oxygen-glucose deprivation (OGD) for 4 h. Western blot analyses were used to evaluate the phosphorylation levels of LR at residues Tyr47 (phospho-Tyr47-LR/pY47-LR) and Thr125 (phospho-Thr125-LR/pT125-LR) and their effects on the phosphorylation of VE-cadherin residue Ser665 (phospho-Ser665-VE-cad). FINDINGS LR over-expression, LRT125A (phosphonull) and LRY47A (phosphonull) treatments were found to reduce the level of phospho-Ser665-VE-cad, and subsequently maintain adherent junctions and endothelial barrier integrity in hypoxic environments. Mechanistically, TIMAP/PP1c can combine with LR on the cell membrane to form a novel LR-TIMAP/PP1c complex. The level of pY47-LR determined the stability of LR-TIMAP/PP1c complex. The binding of TIMAP/PP1c on LR activated the protein phosphatase activity of PP1c and regulated the level of pT125-LR. INTERPRETATION This study demonstrates that low level of phospho-LR reduces no-reflow area through stabilizing the LR-TIMAP/PP1c complex and promoting the stability of adherens junctions, and may help identify new therapeutic targets for the treatment of no-reflow.
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Affiliation(s)
- Xiaoyu Quan
- Thoracic Surgery Laboratory, the First College of Clinical Medicine, Xuzhou Medical University, Xuzhou, Jiangsu 221006, China
| | - Xiucheng Liu
- Thoracic Surgery Laboratory, the First College of Clinical Medicine, Xuzhou Medical University, Xuzhou, Jiangsu 221006, China; Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China
| | - Xichun Qin
- Thoracic Surgery Laboratory, the First College of Clinical Medicine, Xuzhou Medical University, Xuzhou, Jiangsu 221006, China; Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China
| | - Yuzhuo Wang
- Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China
| | - Teng Sun
- Thoracic Surgery Laboratory, the First College of Clinical Medicine, Xuzhou Medical University, Xuzhou, Jiangsu 221006, China; Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China
| | - Zhimin Li
- Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China
| | - Lidong Zhu
- Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China
| | - Jiali Chen
- Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China
| | - Yeqing Zhou
- Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China
| | - Sandeep Singh
- School of International Education, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, Jiangsu 221004, China
| | - Hongyan Dong
- Morphological Research Experiment Center, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, Jiangsu 221004, China
| | - Zhongming Zhang
- Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China.
| | - Hao Zhang
- Thoracic Surgery Laboratory, the First College of Clinical Medicine, Xuzhou Medical University, Xuzhou, Jiangsu 221006, China; Department of Thoracic Surgery, Affifiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, Jiangsu 221006, China.
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6
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Wang X, Li Y, Xiao H, Zhang M, Bao T, Luo X, Chen S. Genotoxicity of microcystin-LR in mammalian cells: Implication from peroxynitrite produced by mitochondria. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 195:110408. [PMID: 32179236 DOI: 10.1016/j.ecoenv.2020.110408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/27/2020] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
Microcystin-LR (MC-LR) is a widely known hepatotoxin which could induce the occurrence and metastasis of hepatocellular carcinoma. In recent years, with the frequent outbreak of cyanobacteria, the harm of MC-LR has gradually attracted more attention. Hence, this study focused on the effect of MC-LR on DNA damage in HepG2 cells, identifying the types and sources of free radicals that make an important function on this issue. Our data suggested that MC-LR induced concentration- and time-dependent increasement of DNA double-strand breaks (DSBs). After exposure to 1 μM MC-LR for 3 days, the protein expression and immunofluorescence staining of γ-H2AX was significantly increased. Using a scavenger of mitochondrial O2.- (4-hydroxy-tempo), a inhibitor of mitochondrial NOS (7-nitroindazole), and a scavenger of ONOO- (uric acid), it was revealed that ONOO- originated from mitochondria made a significant contribution to the genotoxicity of MC-LR. Moreover, a significant decreasement of mitochondrial membrane potential (MMP) was observed. These findings suggested that peroxynitrite targeting mitochondria plays a vital role in the MC-LR-induced genotoxic response in mammalian cells.
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Affiliation(s)
- Xiaofei Wang
- School of Biology, Food and Environment, Hefei University, Hefei, 230601, China; Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China.
| | - Yintao Li
- School of Biology, Food and Environment, Hefei University, Hefei, 230601, China
| | - Hourong Xiao
- School of Biology, Food and Environment, Hefei University, Hefei, 230601, China
| | - Min Zhang
- School of Biology, Food and Environment, Hefei University, Hefei, 230601, China
| | - Teng Bao
- School of Biology, Food and Environment, Hefei University, Hefei, 230601, China
| | - Xun Luo
- School of Biological Engineering, Huainan Normal University, Huainan, 232001, China
| | - Shaopeng Chen
- Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China.
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7
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Zhou Y, Sun M, Tang Y, Chen Y, Zhu C, Yang Y, Wang C, Yu G, Tang Z. Responses of the proteome in testis of mice exposed chronically to environmentally relevant concentrations of Microcystin-LR. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 187:109824. [PMID: 31654863 DOI: 10.1016/j.ecoenv.2019.109824] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 10/13/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
Microcystin-LR (MC-LR), a widespread environmental contaminant, has been shown to have potent acute testicular toxicity. However, magnitudes of toxic effects, induced by MCs, depend on route and magnitude of exposure to the toxin. In the present study, male mice were orally exposed 1, 10 or 100 μg/L MC-LR for 90 or 180 days, and pathological approach and the isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomics were employed with testes. Proteomics revealed that a number of differentially altered proteins may be involved in MC-LR-induced chronic testicular toxicity. The biological process analysis indicated the altered proteins played an important role in biological adhesion, cellular process, response to stimulus or rhythmic process. The cellular component analysis revealed that most of the proteins with altered expression associated with cell part, extracellular region, extracellular region part, membrane, membrane part, organelle or organelle part. The molecular function showed that these proteins were critical in molecular transducer activity. Integrity analyses provide first compelling evidence that MC-LR significantly cause dysfunction of blood-testis barrier (BTB) through affecting tight junctions and gap junctions. Moreover, phosphatidylinositol 3-kinase (PI3K)/AKT eventually contributed to injury result from chronic low-level MC-LR treatment. Identification of proteins in testis responsive to MC-LR provides insights into molecular mechanisms of chronic toxicity of MCs.
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Affiliation(s)
- Yuan Zhou
- Department of Biochemistry and Molecular Biology, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Menghan Sun
- Department of Physiology, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Ye Tang
- Department of Physiology, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Yu Chen
- Research Center of Endocrine and Metabolic Diseases, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Jiangsu Province Academy of Traditonal Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Chan Zhu
- Department of Physiology, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Yan Yang
- Department of Physiology, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Changming Wang
- Department of Physiology, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Guang Yu
- Department of Biochemistry and Molecular Biology, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China.
| | - Zongxiang Tang
- Department of Physiology, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China.
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8
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Huang P, Wang S, Weng D, Xu L. Alpha4-overexpressing HL7702 cells can counteract microcystin-LR effects on cytoskeletal structure. ENVIRONMENTAL TOXICOLOGY 2018; 33:978-987. [PMID: 29984889 DOI: 10.1002/tox.22585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/28/2018] [Accepted: 05/28/2018] [Indexed: 06/08/2023]
Abstract
Our previous studies indicated that α4 was involved in the toxicity of MC-LR on the cytoskeleton via the change of PP2A activity in HEK 293. To explore the role of α4 in MC-LR toxicity via PP2A regulation in different cell lines, the HL7702 cell overexpressing α4 protein was exposed to MC-LR, and the change of PP2A, cytoskeletal structure, and cytoskeleton-related proteins were investigated. The results showed that PP2A activity was decreased, PP2A/C subunit expression and phosphorylation (Tyr307) increased significantly, but methylation (Leu 309)clearly decreased. The structure of the actin filaments and microtubules (MTs) remained unchanged, and the expression and phosphorylation of the cytoskeleton-related proteins showed different changes. In addition, the main components of the MAPK pathway, JNK, P38, and ERK1/2, were activated together. Our results indicated that elevated α4 expression did confer some resistance to MC-LR-induced cytoskeletal changes, but the responses of different cell lines to MC-LR, under the α4-overexpression condition, are not exactly the same.
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Affiliation(s)
- Pu Huang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Sha Wang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Dengpo Weng
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Lihong Xu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
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9
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Essential roles of Akt/Snail pathway in microcystin-LR-induced tight junction toxicity in Sertoli cell. Food Chem Toxicol 2018; 112:290-298. [PMID: 29307602 DOI: 10.1016/j.fct.2018.01.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 01/01/2018] [Accepted: 01/03/2018] [Indexed: 01/17/2023]
Abstract
Microcystin (MC)-LR is a cyclic heptapeptide that acts as a potent reproductive system toxin. However, the underlying pathways of MCLR-induced reproductive system toxicity have not been well elucidated. The blood-testis barrier is mainly constituted by tight junctions (TJs) between adjacent Sertoli cells in the seminiferous epithelium near the basement membrane. The present study was designed to investigate changes in TJs and the underlying pathway in MC-LR-induced TJs toxicity in Sertoli cell. In our study, the transepithelial electrical resistance (TER) value was decreased in a dose dependent manner due to the markers of TJs occludin, claudin and zonula occludens-1 (ZO-1) expression decline. MC-LR is shown to induce cytotoxicity by inhibiting protein phosphatase 2A (PP2A) activity. Our results also showed that the PP2A activity presented a dose-dependent decline. Moreover, MC-LR stimulated protein expression of snail by Akt/GSK-3β activation. The activated Akt/GSK-3β and snail signaling pathway largely accounted for MC-LRinduced TJs toxicity, which could be partially reversed by snail siRNA interference or AKT chemical inhibitor in TM4 cells. These findings indicated that MC-LR inhibit the protein expression of TJs, and the activation of Akt/Snail signaling pathways due to PP2A inhibition is proposed to participate in this process.
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10
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Zhou Y, Xu X, Yu B, Yu G. Characterization of in vitro effects of microcystin-LR on intestinal epithelial cells. ENVIRONMENTAL TOXICOLOGY 2017; 32:1539-1547. [PMID: 27758031 DOI: 10.1002/tox.22375] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/29/2016] [Accepted: 10/05/2016] [Indexed: 06/06/2023]
Abstract
The intestinal epithelium is a single-cell layer that provides an important barrier against natural toxins. Microcystin-LR (MC-LR), a cyclic heptapeptide, is one of the best known toxins able to alter the functions of intestine. This study evaluated the toxic effects and the possible mechanisms of MC-LR on barrier function of the intestinal epithelial cells. Intestinal epithelial cells (IEC-6) were exposed to 0, 6.25, 12.5, 25 and 50 μM MC-LR. Cell viability significantly decreased, while the ratio of apoptotic cells increased after exposure to 12.5μM and higer concentration of MC-LR. As expected, the integrity of a polarized IEC-6 monolayer was affected by MC-LR exposure, as demonstrated by a decrease in the transepithelial electrical resistance (TEER) values, becoming most pronounced at 50μM, 24 h. No effects were detected on the protein expression levels of the tight junction protein claudin at 50μM. However, the expression of occludin and zonula occludens-1 (ZO-1) declined. Furthermore, MC-LR can immigrate into IEC-6 cells. The activity of protein phosphatases 2A (PP2A) decreased from the concentration of 12.5 μM, showing a dose-dependent decline. These results provide new information that strengthens the concept that the intestinal epithelium is important targets for toxic effects of water contaminants like MC-LR. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1539-1547, 2017.
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Affiliation(s)
- Yuan Zhou
- College of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Xiaoping Xu
- Zhejiang Prov Ctr Dis Prevent & Control, Hangzhou, Zhejiang, 310051, China
| | - Beibei Yu
- School of Foreign Languages, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China
| | - Guang Yu
- College of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, 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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