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Chen JH, Tsou TC, Chiu IM, Chou CC. Proliferation Inhibition, DNA Damage, and Cell-Cycle Arrest of Human Astrocytoma Cells after Acrylamide Exposure. Chem Res Toxicol 2010; 23:1449-58. [DOI: 10.1021/tx1000893] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jong-Hang Chen
- Department of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan, Division of Environmental Health and Occupational Medicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, Institute of Cellular and System Medicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, Department of Internal Medicine, The Ohio State University, 480 West Ninth Avenue, Columbus, Ohio 43210, and Center
| | - Tsui-Chun Tsou
- Department of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan, Division of Environmental Health and Occupational Medicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, Institute of Cellular and System Medicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, Department of Internal Medicine, The Ohio State University, 480 West Ninth Avenue, Columbus, Ohio 43210, and Center
| | - Ing-Ming Chiu
- Department of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan, Division of Environmental Health and Occupational Medicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, Institute of Cellular and System Medicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, Department of Internal Medicine, The Ohio State University, 480 West Ninth Avenue, Columbus, Ohio 43210, and Center
| | - Chin-Cheng Chou
- Department of Veterinary Medicine, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan, Division of Environmental Health and Occupational Medicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, Institute of Cellular and System Medicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, Department of Internal Medicine, The Ohio State University, 480 West Ninth Avenue, Columbus, Ohio 43210, and Center
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Yin Z, Milatovic D, Aschner JL, Syversen T, Rocha JB, Souza DO, Sidoryk M, Albrecht J, Aschner M. Methylmercury induces oxidative injury, alterations in permeability and glutamine transport in cultured astrocytes. Brain Res 2006; 1131:1-10. [PMID: 17182013 PMCID: PMC1847599 DOI: 10.1016/j.brainres.2006.10.070] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 10/09/2006] [Accepted: 10/26/2006] [Indexed: 01/12/2023]
Abstract
The neurotoxicity of high levels of methylmercury (MeHg) is well established both in humans and experimental animals. Astrocytes accumulate MeHg and play a prominent role in mediating MeHg toxicity in the central nervous system (CNS). Although the precise mechanisms of MeHg neurotoxicity are ill-defined, oxidative stress and altered mitochondrial and cell membrane permeability appear to be critical factors in its pathogenesis. The present study examined the effects of MeHg treatment on oxidative injury, mitochondrial inner membrane potential, glutamine uptake and expression of glutamine transporters in primary astrocyte cultures. MeHg caused a significant increase in F(2)-isoprostanes (F(2)-IsoPs), lipid peroxidation biomarkers of oxidative damage, in astrocyte cultures treated with 5 or 10 microM MeHg for 1 or 6 h. Consistent with this observation, MeHg induced a concentration-dependant reduction in the inner mitochondrial membrane potential (DeltaPsi(m)), as assessed by the potentiometric dye, tetramethylrhodamine ethyl ester (TMRE). Our results demonstrate that DeltaPsi(m) is a very sensitive endpoint for MeHg toxicity, since significant reductions were observed after only 1 h exposure to concentrations of MeHg as low as 1 microM. MeHg pretreatment (1, 5 and 10 microM) for 30 min also inhibited the net uptake of glutamine ((3)H-glutamine) measured at 1 min and 5 min. Expression of the mRNA coding the glutamine transporters, SNAT3/SN1 and ASCT2, was inhibited only at the highest (10 microM) MeHg concentration, suggesting that the reduction in glutamine uptake observed after 30 min treatment with lower concentrations of MeHg (1 and 5 microM) was not due to inhibition of transcription. Taken together, these studies demonstrate that MeHg exposure is associated with increased mitochondrial membrane permeability, alterations in glutamine/glutamate cycling, increased ROS formation and consequent oxidative injury. Ultimately, MeHg initiates multiple additive or synergistic disruptive mechanisms that lead to cellular dysfunction and cell death.
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MESH Headings
- Amino Acid Transport Systems, Neutral/genetics
- Animals
- Animals, Newborn
- Astrocytes/drug effects
- Astrocytes/metabolism
- Astrocytes/pathology
- Cell Membrane Permeability/drug effects
- Cell Membrane Permeability/physiology
- Cells, Cultured
- Central Nervous System/drug effects
- Central Nervous System/metabolism
- Central Nervous System/physiopathology
- Dose-Response Relationship, Drug
- Glutamic Acid/metabolism
- Glutamine/metabolism
- Lipid Peroxidation/drug effects
- Lipid Peroxidation/physiology
- Membrane Potential, Mitochondrial/drug effects
- Membrane Potential, Mitochondrial/physiology
- Mercury Poisoning, Nervous System/metabolism
- Mercury Poisoning, Nervous System/physiopathology
- Methylmercury Compounds/toxicity
- Mitochondria/drug effects
- Mitochondria/metabolism
- Mitochondria/pathology
- Mitochondrial Membranes/drug effects
- Mitochondrial Membranes/metabolism
- Mitochondrial Membranes/pathology
- Oxidative Stress/drug effects
- Oxidative Stress/physiology
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Reactive Oxygen Species/metabolism
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Affiliation(s)
- Zhaobao Yin
- Department of Pediatrics, Pharmacology, and the Kennedy Center, Norwegian University of Science and Technology, Trondheim, Norway
| | - Dejan Milatovic
- Department of Pediatrics, Pharmacology, and the Kennedy Center, Norwegian University of Science and Technology, Trondheim, Norway
| | - Judy L. Aschner
- Department of Pediatrics, Pharmacology, and the Kennedy Center, Norwegian University of Science and Technology, Trondheim, Norway
| | - Tore Syversen
- Department of Clinical Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
| | - Joao B.T. Rocha
- Departamento de Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Brazil
| | - Diogo O. Souza
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Marta Sidoryk
- Department of Neurotoxicology, Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Jan Albrecht
- Department of Neurotoxicology, Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Michael Aschner
- Department of Pediatrics, Pharmacology, and the Kennedy Center, Norwegian University of Science and Technology, Trondheim, Norway
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Wu Q, Sidoryk M, Mutkus L, Zielińska M, Albrecht J, Aschner M. Acrylamide stimulates glutamine uptake in Fischer 344 rat astrocytes by a mechanism involving upregulation of the amino acid transport system N. Ann N Y Acad Sci 2006; 1053:435-43. [PMID: 16179550 DOI: 10.1111/j.1749-6632.2005.tb00052.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
High demand of neoplastic tissues for glutamine (Gln) is met by its active transport across cell membranes. Chronic treatment with acrylamide in rodents is associated with an increased incidence of neoplasms, including astrocytomas. In this study, 24-h acrylamide treatment significantly increased the initial rate of l-[G-3H]glutamine uptake in astrocyte cultures derived from the acrylamide-sensitive Fischer 344 rat, and this effect could be fully inhibited by histidine, a model substrate for the amino acid transport system N. RT-PCR analysis revealed that acrylamide treatment caused a significant increase in the astrocytic expression of the mRNA coding for the major system N protein, SNAT3, which is specifically overexpressed in malignant gliomas in situ. The acrylamide-induced upregulation of astrocytic Gln transport via system N is likely to affect Gln homeostasis in these cells and may be causally related to the increased astrocytoma incidence observed in Fischer 344 rats.
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Affiliation(s)
- Qi Wu
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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