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Role of TRPM2 in brain tumours and potential as a drug target. Acta Pharmacol Sin 2022; 43:759-770. [PMID: 34108651 DOI: 10.1038/s41401-021-00679-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/07/2021] [Indexed: 02/06/2023] Open
Abstract
Ion channels are ubiquitously expressed in almost all living cells, and are the third-largest category of drug targets, following enzymes and receptors. The transient receptor potential melastatin (TRPM) subfamily of ion channels are important to cell function and survival. Studies have shown upregulation of the TRPM family of ion channels in various brain tumours. Gliomas are the most prevalent form of primary malignant brain tumours with no effective treatment; thus, drug development is eagerly needed. TRPM2 is an essential ion channel for cell function and has important roles in oxidative stress and inflammation. In response to oxidative stress, ADP-ribose (ADPR) is produced, and in turn activates TRPM2 by binding to the NUDT9-H domain on the C-terminal. TRPM2 has been implicated in various cancers and is significantly upregulated in brain tumours. This article reviews the current understanding of TRPM2 in the context of brain tumours and overviews the effects of potential drug therapies targeting TRPM2 including hydrogen peroxide (H2O2), curcumin, docetaxel and selenium, paclitaxel and resveratrol, and botulinum toxin. It is long withstanding knowledge that gliomas are difficult to treat effectively, therefore investigating TRPM2 as a potential therapeutic target for brain tumours may be of considerable interest in the fields of ion channels and pharmacology.
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2
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Aras S, Efendioğlu M, Wulamujiang A, Ozkanli SS, Keleş MS, Tanzer İO. Radioprotective effect of melatonin against radiotherapy-induced cerebral cortex and cerebellum damage in rat. Int J Radiat Biol 2021; 97:348-355. [PMID: 33320758 DOI: 10.1080/09553002.2021.1864047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
PURPOSE The present study aims to investigate the radioprotective effect of melatonin (MEL) against early period brain damage caused by different dose rate beams in the experimental rat model. MATERIALS AND METHODS Forty-eight Sprague Dawley rats were randomly divided into six groups; the control, only melatonin, low dose rate-radiotherapy (LDR-RT), high dose rate-radiotherapy (HDR-RT) groups and (LDR-RT) + MEL and (HDR-RT) + MEL radiotherapy plus melatonin groups. Each rat administered melatonin was given a dose of 10 mg/kg through intraperitoneal injection, 15 minutes before radiation exposure. The head and neck region of each rat in only radiotherapy and radiotherapy plus melatonin groups was irradiated with a single dose of 16 Gy in LDR-RT and HDR-RT beams. Rats in all groups were examined for histopathology and biochemistry analysis 10 days after radiotherapy. RESULTS Comparing the findings for LDR-RT and HDR-RT only radiotherapy groups and the control group, there was a statistically significant difference in histopathological and biochemical parameters, however, melatonin administered in radiotherapy plus melatonin groups contributed improving these parameters (p < .05). There was no statistically significant difference between LDR-RT and HDR-RT beams (p > .05). CONCLUSIONS It was concluded that melatonin applied before LDR-RT and HDR-RT radiotherapy protected early period radiotherapy-induced brain damage. The effects of clinically low and high dose beams on the cerebral cortex and cerebellum were investigated histopathologically for the first time. HDR beams can be safely applied in brain radiotherapy. However, more experimental rat and clinical studies are needed to explain the radiobiological uncertainties about the clinic dose rate on different cancerous and healthy tissues.
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Affiliation(s)
- Serhat Aras
- Medical Imaging Techniques Programme, University of Health Sciences Turkey, Istanbul, Turkey
| | - Mustafa Efendioğlu
- Department of Neurosurgery, Haydarpaşa Numune Training and Research Hospital, University of Health Sciences Turkey, Istanbul, Turkey
| | - Aini Wulamujiang
- Medical Imaging Techniques Programme, University of Health Sciences Turkey, Istanbul, Turkey
| | - Sidika Seyma Ozkanli
- Department of Pathology, Göztepe Training and Research Hospital, Medeniyet University, Istanbul, Turkey
| | - Mevlüt Sait Keleş
- Department of Medical Biochemistry, Faculty of Medicine, Ataturk University, Erzurum, Turkey
| | - İhsan Oğuz Tanzer
- Biomedical Technology Programme, University of Health Sciences Turkey, Istanbul, Turkey
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3
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Isık A, Atamanalp M, Alak G. Evaluation of antioxidant level and protein oxidation of rainbow trout (Oncorhynchus mykiss) fillets during rigor and post‐rigor. J Food Saf 2019. [DOI: 10.1111/jfs.12746] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Abdulcelil Isık
- Graduate School of Natural and Applied Sciences Erzurum Turkey
| | - Muhammed Atamanalp
- Department of Fisheries and Seafood Processing Technology, Faculty of FisheriesAtatürk University Erzurum Turkey
| | - Gonca Alak
- Department of Fisheries and Seafood Processing Technology, Faculty of FisheriesAtatürk University Erzurum Turkey
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Zhang Q, Lyu W, Yu M, Niu Y, Meng Z. Investigating the inotropic effect of pyruvic acid on the isolated rat heart and its underlying mechanism. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2019; 71:103206. [PMID: 31212135 DOI: 10.1016/j.etap.2019.103206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 05/09/2019] [Accepted: 06/06/2019] [Indexed: 06/09/2023]
Abstract
Pyruvic acid is important organic chemical intermediates that plays a role in cardiomyocyte pathophysiology and therapy. This study sought to explore the inotropic effects of pyruvic acid on the function of the isolated rat hearts and investigate its underlying mechanism. Pyruvic acid produced a greater negative inotropic effect compared to HCl and sodium pyruvate in a concentration-dependent pattern in the hearts. The role of low dose of pyruvic acid on heart function was regulated by pyruvic acid molecules and high dose pyruvic acid may be influenced by pyruvic acid molecules and pH. Kv channels may be involved in the pyruvic acid-induced negative inotropic effect. Finally, pyruvic acid markedly increased the level of LDH and CK and reduced the level of Ca2+Mg2+-ATPase and Na+K+-ATPase. These results suggest that pyruvic acid may modulate cardiac function at physiological or low doses but can cause damage to cardiomyocytes at high doses.
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Affiliation(s)
- Quanxi Zhang
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China.
| | - Wenru Lyu
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China
| | - Mengbin Yu
- Institute of NBC Defence, Beijing 102205, China
| | - Yuxin Niu
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China
| | - Ziqiang Meng
- Institute of Environmental Medicine and Toxicology, Institute of Environmental Science, Shanxi University, Taiyuan 030006, China
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5
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Pardeep Singh, Kumar M, Bansal N. Azelnidipine Ameliorates Dementia in Streptozotocin Treated Rats: Interplay between Oxidative Stress and Calcium. NEUROCHEM J+ 2019. [DOI: 10.1134/s1819712419030139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Badillo-Ramírez I, Saniger JM, Rivas-Arancibia S. 5-S-cysteinyl-dopamine, a neurotoxic endogenous metabolite of dopamine: Implications for Parkinson's disease. Neurochem Int 2019; 129:104514. [PMID: 31369776 DOI: 10.1016/j.neuint.2019.104514] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/04/2019] [Accepted: 07/29/2019] [Indexed: 12/13/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide and is characterized for being an idiopathic and multifactorial disease. Extensive research has been conducted to explain the origin of the disease, but it still remains elusive. It is well known that dopamine oxidation, through the endogenous formation of toxic metabolites, is a key process in the activation of a cascade of molecular events that leads to cellular death in the hallmark of PD. Thio-catecholamines, such as 5-S-cysteinyl-dopamine, 5-S-glutathionyl-dopamine and derived benzothiazines, are endogenous metabolites formed in the dopamine oxidative degradation pathway. Those metabolites have been shown to be highly toxic to neurons in the substantia nigra pars compacta, activating molecular mechanisms that ultimately lead to neuronal death. In this review we describe the origin, formation and the toxic effects of 5-S-cysteinyl-dopamine and its oxidative derivatives that cause death to dopaminergic neurons. Furthermore, we correlate the formation of those metabolites with the neurodegeneration progress in PD. In addition, we present the reported neuroprotective strategies of products that protect against the cellular damage of those thio-catecholamines. Finally, we discuss the advantages in the use of 5-S-cysteinyl-dopamine as a potential biomarker for PD.
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Affiliation(s)
- Isidro Badillo-Ramírez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito externo S/N, Cd. Universitaria, 04510, Ciudad de México, Mexico; Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito externo S/N, Cd. Universitaria, 04510, Ciudad de México, Mexico
| | - José M Saniger
- Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito externo S/N, Cd. Universitaria, 04510, Ciudad de México, Mexico.
| | - Selva Rivas-Arancibia
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito externo S/N, Cd. Universitaria, 04510, Ciudad de México, Mexico.
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7
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Alak G, Yeltekin AÇ, Özgeriş FB, Parlak V, Uçar A, Sait Keleş M, Atamanalp M. Therapeutic effect of N- acetyl cysteine as an antioxidant on rainbow trout's brain in cypermethrin toxicity. CHEMOSPHERE 2019; 221:30-36. [PMID: 30634146 DOI: 10.1016/j.chemosphere.2018.12.196] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/27/2018] [Accepted: 12/29/2018] [Indexed: 06/09/2023]
Abstract
The aim of this study was to investigate the therapeutic effect of N-acetylcystein (NAC) against oxidative stress induced by Cypermethrin pesticide in rainbow trout (Oncorhynchus mykiss). The experiment was designed as 5 groups (A, B, C, D, and E). Group A was organized as control group and had no treatment. The other groups were treated with Cypermethrin for 14 days. At the end of this period, Groups B (1.0 mM NAC) and D (0.5 mM NAC) was performed with NAC for 96 h. Group C was not administered NAC, the recovery process was evaluated with this group. Group E was exposed to cypermethrin during 14 days and sampled. Acetylcholinesterase (AChE), malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), paraoxonase (PON), arylesterase (AR), myeloperoxidase (MPO) activities, oxidative DNA damage (8-hydroxy-2'-deoxyguanosine (8-OHdG)), caspase-3 levels, and trace elements contents analyses were performed in all fish brains. According to the results, MDA, MPO, 8-OHdG and caspase-3 levels were significantly decreased compared to the other groups (pesticide and recovery) (p < 0.05), AChE, SOD, CAT, GPx, PON, and AR activities increased (p < 0.05). In brain tissue, no statistically significant difference was observed in trace element analysis of all application groups. According to the obtained data, the positive effect of N-acetylcysteine on protein synthesis, detoxification, and diverse metabolic functions against cypermethrin toxicity has been more effective in 1.0 mM NAC. NAC has important therapeutic effect on pesticide-induced neurotoxicity for fish in terms of all data. It was concluded that NAC has an antioxidant effect against pesticide-induced oxidative stress and the selected biochemical markers are useful for such studies.
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Affiliation(s)
- Gonca Alak
- Department of Aquaculture, Faculty of Fisheries, Ataturk University, TR-25030 Erzurum, Turkey.
| | - Aslı Çilingir Yeltekin
- Department of Chemistry, Faculty of Science, University of Yüzüncü Yıl, TR-65080, Van, Turkey
| | - Fatma Betül Özgeriş
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Ataturk University, TR-25030 Erzurum, Turkey
| | - Veysel Parlak
- Department of Aquaculture, Faculty of Fisheries, Ataturk University, TR-25030 Erzurum, Turkey
| | - Arzu Uçar
- Department of Aquaculture, Faculty of Fisheries, Ataturk University, TR-25030 Erzurum, Turkey
| | - M Sait Keleş
- Department of Biochemistry, Faculty of Medicine, Ataturk University, TR-25030 Erzurum, Turkey
| | - Muhammed Atamanalp
- Department of Aquaculture, Faculty of Fisheries, Ataturk University, TR-25030 Erzurum, Turkey.
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Belrose JC, Jackson MF. TRPM2: a candidate therapeutic target for treating neurological diseases. Acta Pharmacol Sin 2018; 39:722-732. [PMID: 29671419 PMCID: PMC5943913 DOI: 10.1038/aps.2018.31] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 02/24/2018] [Indexed: 12/25/2022] Open
Abstract
Transient receptor potential melastatin 2 (TRPM2) is a calcium (Ca2+)-permeable non-selective cation channel belonging to the TRP ion channel family. Oxidative stress-induced TRPM2 activation provokes aberrant intracellular Ca2+ accumulation and cell death in a variety of cell types, including neurons. Aberrant TRPM2 function has been implicated in several neurological disorders including ischemia/stroke, Alzheimer's disease, neuropathic pain, Parkinson's disease and bipolar disorder. In addition to research identifying a role for TRPM2 in disease, progress has been made in the identification of physiological functions of TRPM2 in the brain, including recent evidence that TRPM2 is necessary for the induction of N-methyl-D-aspartate (NMDA) receptor-dependent long-term depression, an important form of synaptic plasticity at glutamate synapses. Here, we summarize recent evidence on the role of TRPM2 in the central nervous system (CNS) in health and disease and discuss the potential therapeutic implications of targeting TRPM2. Collectively, these studies suggest that TRPM2 represents a prospective novel therapeutic target for neurological disorders.
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Affiliation(s)
- Jillian Corinne Belrose
- Department of Anesthesia & Perioperative Medicine, Schulich Medicine & Dentistry, Western University, London, Ontario, N6A 5A5, Canada
- E-mail
| | - Michael Frederick Jackson
- Department of Pharmacology and Therapeutics, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, R3E 0T6, Canada
- Neuroscience Research Program, Kleysen Institute for Advanced Medicine, Health Sciences Centre, Winnipeg, Manitoba, R3E 3J7, Canada
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9
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Lee W, Lee DG. A novel mechanism of fluconazole: fungicidal activity through dose-dependent apoptotic responses in Candida albicans. Microbiology (Reading) 2018; 164:194-204. [DOI: 10.1099/mic.0.000589] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Wonjong Lee
- School of Life Sciences, BK 21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Republic of Korea
| | - Dong Gun Lee
- School of Life Sciences, BK 21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Republic of Korea
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10
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Rakkestad KE, Sørvik IB, Øverby GR, Debernard KAB, Mathisen GH, Paulsen RE. 17α-Estradiol down-regulates glutathione synthesis in serum deprived PC-12 cells. Free Radic Res 2014; 48:1170-8. [DOI: 10.3109/10715762.2014.930455] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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11
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Smeyne M, Smeyne RJ. Glutathione metabolism and Parkinson's disease. Free Radic Biol Med 2013; 62:13-25. [PMID: 23665395 PMCID: PMC3736736 DOI: 10.1016/j.freeradbiomed.2013.05.001] [Citation(s) in RCA: 300] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 05/01/2013] [Accepted: 05/01/2013] [Indexed: 12/14/2022]
Abstract
It has been established that oxidative stress, defined as the condition in which the sum of free radicals in a cell exceeds the antioxidant capacity of the cell, contributes to the pathogenesis of Parkinson disease. Glutathione is a ubiquitous thiol tripeptide that acts alone or in concert with enzymes within cells to reduce superoxide radicals, hydroxyl radicals, and peroxynitrites. In this review, we examine the synthesis, metabolism, and functional interactions of glutathione and discuss how these relate to the protection of dopaminergic neurons from oxidative damage and its therapeutic potential in Parkinson disease.
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Affiliation(s)
- Michelle Smeyne
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, 901-595-3066
| | - Richard Jay Smeyne
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, 901-595-2830
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Kim JH, Xu EY, Sacks DB, Lee J, Shu L, Xia B, Kong ANT. Identification and functional studies of a new Nrf2 partner IQGAP1: a critical role in the stability and transactivation of Nrf2. Antioxid Redox Signal 2013; 19:89-101. [PMID: 22793650 PMCID: PMC3689176 DOI: 10.1089/ars.2012.4586] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS Nuclear factor-erythroid-related factor 2 (Nrf2) is a critical transcriptional factor that is used in regulating cellular defense against oxidative stress. This study is aimed at investigating new interacting protein partners of Nrf2 using One-strep tag pull-down coupled with LTQ Orbitrap LC/MS/MS, and at examining the impact on Nr2 signaling by the newly identified IQ motif containing GTPase activating protein 1 (IQGAP1). RESULTS Using the One-strep tag pull-down and LTQ Orbitrap LC/MS/MS, we identified IQGAP1 as a new Nrf2 interacting partner. Direct interactions between IQGAP1 and Nrf2 proteins were verified using in vitro glutathione S-transferase (GST) pull-down, transcription/translation assays, and in vivo utilizing Nrf2 overexpressing cells. Coexpression of Dsredmono-IQGAP1 and eGFP-Nrf2 increased the stability of eGFP-Nrf2 and enhanced the expression of Nrf2-target gene heme oxygenase-1 (HO-1). To confirm the functional role of IQGAP1 on Nrf2, knock-downed IQGAP1 using siIQGAP1 attenuated the expression of endogenous Nrf2, HO-1 proteins, and Nrf2-target genes GSTpi, GCLC, and NAD(P)H quinone oxidoreductase 1 (NQO-1). Furthermore, the stability of Nrf2 was dramatically decreased in IQGAP1-deficient mouse embryonic fibroblast (MEF) cells. Since IQGAP1 signaling could be mediated by calcium, treating the cells with calcium showed the translocation of IQGAP1/Nrf2 complex into the nucleus, suggesting that IQGAP1 may play a critical role in Nrf2 stability. Interestingly, consistent with calcium signaling for IQGAP1, treating the cells with calcium functionally enhanced Nrf2-mediated antioxidant responsive element-transcription activity and enhanced the expression of the endogenous Nrf2-target gene HO-1. INNOVATION In the aggregate, our current study identifies and functionally characterizes a new Nrf2 partner protein IQGAP1, which may contribute to Nrf2's regulation of antioxidant enzymes such as HO-1. CONCLUSION IQGAP1 may play a critical role in the stability and transactivation of Nrf2.
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Affiliation(s)
- Jung-Hwan Kim
- Graduate Program in Pharmaceutical Science, Center for Cancer Prevention Research, Ernest-Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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Nazıroğlu M, Özgül C, Küçükayaz M, Çiğ B, Hebeisen S, Bal R. Selenium modulates oxidative stress-induced TRPM2 cation channel currents in transfected Chinese hamster ovary cells. Basic Clin Pharmacol Toxicol 2012; 112:96-102. [PMID: 22905852 DOI: 10.1111/j.1742-7843.2012.00934.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 08/09/2012] [Indexed: 01/16/2023]
Abstract
It has been recently reported that the essential antioxidant element selenium has protective effects on cytosolic Ca(2+) levels in cell lines. However, the effects of selenium on like transient receptor potential melastatin 2 (TRPM2) in response to oxidative stress (H(2) O(2) ) are not well understood. We investigated the effects of selenium on H(2) O(2) -induced TRPM2 channel currents in the Chinese hamster ovary (CHO) cell line using patch-clamp and fura-2 fluorescence imaging techniques.
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Affiliation(s)
- Mustafa Nazıroğlu
- Department of Biophysics, Medical Faculty, Süleyman Demirel University, Isparta, Turkey.
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Zhang Q, Meng Z. The inotropic effects of ammonia on isolated perfused rat hearts and the mechanisms involved. ACTA ACUST UNITED AC 2012; 214:4048-54. [PMID: 22071197 DOI: 10.1242/jeb.055947] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ammonia (NH(3)) is a common exogenous gas in the atmosphere, as well as an endogenous chemical produced by amino acid catabolism and other pathways in vivo. Physiological and pathophysiological roles of NH(3) in the nervous system have been studied. Recently, endogenous NH(3) has been suggested to be a gas transmitter. However, so far the role of NH(3) in cardiovascular functions has not been reported. The present study was designed to investigate the inotropic effects of NH(3) on isolated perfused rat hearts and the possible mechanisms involved in these effects. The results showed that NH(3) had a positive inotropic effect in a concentration-dependent manner and produced a higher positive effect than NaOH and NH(4)Cl. At low concentrations, the effect of NH(3) on cardiac function was caused by NH(3) molecules; at high concentrations, the effect of NH(3) on hearts may be partly correlated with a change of pH value, but was mainly caused by NH(3) molecules. The mechanisms involved in the NH(3)-induced positive inotropic effect may be related to the ATP-sensitive K(+) (K(ATP)) channel and the nitric oxide (NO)-cyclic GMP (cGMP) signaling pathway. In addition, at a concentration of 1.5 mmol l(-1), NH(3) significantly increased the activity of creatine kinase (CK) and lactate dehydrogenase (LDH) in the coronary perfusate and decreased the activity of Na(+),K(+)-ATPase and Ca(2+),Mg(2+)-ATPase in the hearts. These results indicate that NH(3) at physiological or low concentrations may play a modulatory role in heart function, but at high concentrations had a damaging effect on isolated rat hearts.
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Affiliation(s)
- Quanxi Zhang
- Institute of Environmental Medicine and Toxicology, Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006, China
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15
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Real MA, Simón MP, Heredia R, de Diego Y, Guirado S. Phenotypic changes in calbindin D28K immunoreactivity in the hippocampus of Fmr1 knockout mice. J Comp Neurol 2011; 519:2622-36. [PMID: 21491426 DOI: 10.1002/cne.22643] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Fragile X syndrome (FXS), the most prevalent form of inherited mental retardation, is caused by the lack of FMRP (fragile mental retardation protein) as a result of the transcriptional silencing of the FMR1 gene. Here we analyze the immunohistochemical expression of the calbindin D28K protein in the hippocampus of Fmr1 knockout (KO) mice and compare it with that of their wildtype (WT) littermates. The spatial distribution pattern of calbindin-immunoreactive cells in the hippocampus was similar in WT and KO mice but for each age studied (ranging from 3.5-8 months) the dentate gyrus of Fmr1-KO mice showed a significant reduction in calbindin-immunoreactive granule cells. Also, the number of calbindin-immunoreactive cells was reduced in the CA1 pyramidal layer in KO mice compared to their WT littermates. In addition, Frm1-KO mice showed a group of calbindin-immunoreactive cells located only in the left CA3b subregion that was only sometimes observed in WT mice. Overall, the absence of FMRP results in a dysregulation of the calbindin protein expression in the hippocampus. This dysregulation is cell type- and time-dependent and as a consequence key elements of the hippocampal trisynaptic circuitry may lack calbindin in critical periods for normal memory/learning abilities to be achieved and may explain some of the FXS symptoms observed in the Fmr1-KO mouse model.
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Affiliation(s)
- M Angeles Real
- University of Málaga, Department of Cell Biology, Genetics, and Physiology, Málaga, Spain
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Differential Effect of Nimodipine in Attenuating Iron-Induced Toxicity in Brain- and Blood–Brain Barrier-Associated Cell Types. Neurochem Res 2011; 37:134-42. [DOI: 10.1007/s11064-011-0591-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/13/2011] [Accepted: 08/29/2011] [Indexed: 10/17/2022]
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17
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Prigol M, Brüning CA, Nogueira CW, Zeni G. The role of the glutathione system in seizures induced by diphenyl diselenide in rat pups. Chem Biol Interact 2011; 193:65-70. [DOI: 10.1016/j.cbi.2011.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 05/09/2011] [Accepted: 05/11/2011] [Indexed: 11/29/2022]
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18
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Botta D, White CC, Vliet-Gregg P, Mohar I, Shi S, McGrath MB, McConnachie LA, Kavanagh TJ. Modulating GSH Synthesis Using Glutamate Cysteine Ligase Transgenic and Gene-Targeted Mice. Drug Metab Rev 2008; 40:465-77. [DOI: 10.1080/03602530802186587] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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19
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Hidalgo C, Donoso P. Crosstalk between calcium and redox signaling: from molecular mechanisms to health implications. Antioxid Redox Signal 2008; 10:1275-312. [PMID: 18377233 DOI: 10.1089/ars.2007.1886] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Studies done many years ago established unequivocally the key role of calcium as a universal second messenger. In contrast, the second messenger roles of reactive oxygen and nitrogen species have emerged only recently. Therefore, their contributions to physiological cell signaling pathways have not yet become universally accepted, and many biological researchers still regard them only as cellular noxious agents. Furthermore, it is becoming increasingly apparent that there are significant interactions between calcium and redox species, and that these interactions modify a variety of proteins that participate in signaling transduction pathways and in other fundamental cellular functions that determine cell life or death. This review article addresses first the central aspects of calcium and redox signaling pathways in animal cells, and continues with the molecular mechanisms that underlie crosstalk between calcium and redox signals under a number of physiological or pathological conditions. To conclude, the review focuses on conditions that, by promoting cellular oxidative stress, lead to the generation of abnormal calcium signals, and how this calcium imbalance may cause a variety of human diseases including, in particular, degenerative diseases of the central nervous system and cardiac pathologies.
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Affiliation(s)
- Cecilia Hidalgo
- Centro FONDAP de Estudios Moleculares de la Célula and Programa de Biología Molecular y Celular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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20
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Naziroğlu M, Lückhoff A. Effects of antioxidants on calcium influx through TRPM2 channels in transfected cells activated by hydrogen peroxide. J Neurol Sci 2008; 270:152-8. [PMID: 18442831 DOI: 10.1016/j.jns.2008.03.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Revised: 01/22/2008] [Accepted: 03/07/2008] [Indexed: 01/12/2023]
Abstract
Melastatin-like transient receptor potential 2 (TRPM2) channel is a redox sensitive Ca(2+)-permeable cation channel that can be gated by H(2)O(2) binding to the channel's enzymatic Nudix domain. Since the mechanisms that lead to TRPM2 action in response to H(2)O(2) are not understood, we examined the effects of various antioxidants on H(2)O(2)-induced TRPM2 cation channel currents in transfected Chinese hamster ovary (CHO) cells. The CHO cells were transfected with cDNA coding for TRPM2. Membrane currents were measured with the conventional whole cell patch-clamp technique. The intracellular solution contained ethylenediamine tetraacetic acid (EDTA) as a chelator for Ca(2+) and heavy metal ions instead of ethylene glycol tetraacetic acid (EGTA). Moreover, we chose an intracellular Ca(2+) concentration calculated to be in the range of 1 microM. H(2)O(2) (10 mM) was added extracellularly to the bath chamber. With these conditions, we were able to evoke TRPM2 currents consistently with H(2)O(2). We next tested whether vitamins C and E or glutathione (GSH) would prevent or attenuate the induction of TRPM2 currents by H(2)O(2) when applied extracellularly or intracellularly. Unexpectedly, administration of these antioxidants did not inhibit activation of TRPM2 by H(2)O(2). In conclusion, TRPM2 channels were constitutively activated by H(2)O(2) although we could not detect any inhibitory effect of the antioxidants on H(2)O(2)-induced TRPM2 cation channel currents in CHO cells.
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Affiliation(s)
- Mustafa Naziroğlu
- Department of Biophysics, Medical Faculty, Süleyman Demirel University, TR-32260, Isparta, Turkey.
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21
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Gaasch JA, Geldenhuys WJ, Lockman PR, Allen DD, Van der Schyf CJ. Voltage-gated calcium channels provide an alternate route for iron uptake in neuronal cell cultures. Neurochem Res 2007; 32:1686-93. [PMID: 17404834 DOI: 10.1007/s11064-007-9313-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Accepted: 02/08/2007] [Indexed: 10/23/2022]
Abstract
Recent studies suggest that iron enters cardiomyocytes via the L-type voltage-gated calcium channel (VGCC). The neuronal VGCC may also provide iron entry. As with calcium, extraneous iron is associated with the pathology and progression of neurodegenerative diseases such as Parkinson's and Alzheimer's disease. VGCCs, ubiquitously expressed, may be an important route of excessive entry for both iron and calcium, contributing to cell toxicity or death. We evaluated the uptake of (45)Ca(2+) and (55)Fe(2+) into NGF-treated rat PC12, and murine N-2alpha cells. Iron not only competed with calcium for entry into these cells, but iron uptake (similar to calcium uptake) was inhibited by nimodipine, a specific L-type VGCC blocker, and enhanced by FPL 64176, an L-VGCC activator, in a dose-dependent manner. Taken together, these data suggest that voltage-gated calcium channels are an alternate route for iron entry into neuronal cells under conditions that promote cellular iron overload toxicity.
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Affiliation(s)
- Julie A Gaasch
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, School of Pharmacy, Amarillo, Texas 79106, USA
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22
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Gaasch JA, Lockman PR, Geldenhuys WJ, Allen DD, Van der Schyf CJ. Brain Iron Toxicity: Differential Responses of Astrocytes, Neurons, and Endothelial Cells. Neurochem Res 2007; 32:1196-208. [PMID: 17404839 DOI: 10.1007/s11064-007-9290-4] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Accepted: 01/11/2007] [Indexed: 10/23/2022]
Abstract
Iron accumulation or iron overload in brain is commonly associated with neurodegenerative disorders such as Parkinson's and Alzheimer's diseases, and also plays a role in cellular damage following hemorrhagic stroke and traumatic brain injury. Despite the brain's highly regulated system for iron utilization and metabolism, these disorders often present following disruptions within iron metabolic pathways. Such dysregulation allows saturation of proteins involved in iron transport and storage, and may cause an increase in free ferrous iron within brain leading to oxidative damage. Not only do astrocytes, neurons, and brain endothelial cells serve unique purposes within the brain, but their individual cell types are equipped with distinct protective mechanisms against iron-induced injury. This review evaluates iron metabolism within the brain under homeostatic and pathological conditions and focuses on the mechanism(s) of brain cellular iron toxicity and differential responses of astrocytes, neurons, and brain vascular endothelial cells to excessive free iron.
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Affiliation(s)
- Julie A Gaasch
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX 79106-1712, USA
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McDermott C, Allshire A, van Pelt FNAM, Heffron JJA. Sub-chronic toxicity of low concentrations of industrial volatile organic pollutants in vitro. Toxicol Appl Pharmacol 2007; 219:85-94. [PMID: 17239415 DOI: 10.1016/j.taap.2006.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 11/23/2006] [Accepted: 12/05/2006] [Indexed: 01/26/2023]
Abstract
Organic solvents form an important class of pollutants in the ambient air and have been associated with neurotoxicity and immunotoxicity in humans. Here we investigated the biological effects of sub-chronic exposure to industrially important volatile organic solvents in vitro. Jurkat T cells were exposed to toluene, n-hexane and methyl ethyl ketone (MEK) individually for 5 days and solvent exposure levels were confirmed by headspace gas chromatography. A neuroblastoma cell line (SH-SY5Y) was exposed to toluene for the same period. Following exposure, cells were harvested and toxicity measured in terms of the following endpoints: membrane damage (LDH leakage), perturbations in intracellular free Ca(2+), changes in glutathione redox status and dual-phosphorylation of MAP kinases ERK1/2, JNK and p38. The results show that sub-chronic exposure to the volatile organic solvents causes membrane damage, increased intracellular free calcium and altered glutathione redox status in both cell lines. However, acute and sub-chronic solvent exposure did not result in MAP kinase phosphorylation. Toxicity of the solvents tested increased with hydrophobicity. The lowest-observed-adverse-effect-levels (LOAELs) measured in vitro were close to blood solvent concentrations reported for individuals exposed to the agents at levels at or below their individual threshold limit values (TLVs).
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24
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Geng H, Meng Z, Zhang Q. In vitro responses of rat alveolar macrophages to particle suspensions and water-soluble components of dust storm PM2.5. Toxicol In Vitro 2006; 20:575-84. [PMID: 16326066 DOI: 10.1016/j.tiv.2005.09.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 09/14/2005] [Accepted: 09/28/2005] [Indexed: 11/26/2022]
Abstract
A study was conducted to investigate the in vitro toxicities of dust storm particulate matter with an aerodynamic diameter < or = 2.5 microm (PM(2.5)) on rat alveolar macrophages (AM). This was based on the ambient PM(2.5) collected in March 2004 from Baotou city, Inner Mongolia Autonomous Region, China. The particles were classified as normal (from sunshiny and clean days) and dust storm samples according to the dust storm classification, and the local weather and air quality monitoring data. The cell viability, levels of cellular thiobarbituric acid-reactive species (TBARS), glutathione (GSH), and cytosolic free calcium ions (Ca(2+)), and the plasma membrane ATPase activities and membrane lipid fluidity were determined 4h following the in vitro treatment of AM with differing dosages of the collected samples. Results revealed that dust storm PM(2.5) and their water-soluble fractions at high dosages generated oxidant stress on AM, induced leakage of lactate dehydrogenase (LDH), significantly decreased activities of plasma membrane Na(+)K(+)-ATPase, increased intracellular Ca(2+) levels, and led to significant alterations in membrane lipid fluidity, finally resulting in cytotoxicity. A two-way ANOVA showed that there was no significant difference in the above indices measured between the normal and dust storm PM(2.5), suggesting the deleterious effects of ambient PM(2.5) from Baotou city were based on the dose used rather than the type of particles. But due to a higher concentration of airborne PM(2.5) mass concentration in dust storm days than that in normal days, it concluded that during dust storm episodes, a much more serious effect on AM was imminent.
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Affiliation(s)
- Hong Geng
- Institute of Environmental Medicine and Toxicology, Shanxi University, Taiyuan 030006, PR China
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25
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Yang W, Tiffany-Castiglioni E. The bipyridyl herbicide paraquat produces oxidative stress-mediated toxicity in human neuroblastoma SH-SY5Y cells: relevance to the dopaminergic pathogenesis. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2005; 68:1939-61. [PMID: 16263688 DOI: 10.1080/15287390500226987] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Paraquat (PQ) is a cationic nonselective bipyridyl herbicide widely used to control weeds and grasses in agriculture. Epidemiologic studies indicate that exposure to pesticides can be a risk factor in the incidence of Parkinson's disease (PD). A strong correlation has been reported between exposure to paraquat and PD incidence in Canada, Taiwan, and the United States. This correlation is supported by animal studies showing that paraquat produces toxicity in dopaminergic neurons of the rat and mouse brain. However, it is unclear how paraquat triggers toxicity in dopaminergic neurons. Based on the prooxidant properties of paraquat, it was hypothesized that paraquat may induce oxidative stress-mediated toxicity in dopaminergic neurons. To explore this possibility, dopaminergic SH-SY5Y cells were treated with paraquat, and several biomarkers of oxidativestress were measured. First, a specific dopamine transporter inhibitor GBR12909 significantly protected SY5Y cells against the toxicity of paraquat, indicating that paraquat exerts its toxicity by a mechanism involving the dopamine transporter (DAT). Second, paraquat increased intracellular levels of reactive oxygen species (ROS), but decreased the levels of glutathione. Third, paraquat inhibited glutathione peroxidase activity, but did not affect glutathione reductase activity. On the other hand, paraquat increased GST activity by 24 h, after which GST activity returned to the control value at 48 h. Fourth, paraquat dissipated mitochondrial transmembrane potential (MTP). Fifth, paraquat produced increases of malondialdehyde (MDA) and protein carbonyls, as well as DNA fragmentation, indicating oxidative damage to major cellular components. Sixth, paraquat increased the protein level of heme oxygenase-1 (HO-1). Taken together, these findings verify our hypothesis that paraquat produces oxidative stress-mediated toxicity in SH-SY5Y cells. Thus, current findings suggest that paraquat may induce the pathogenesis of dopaminergic neurons through oxidative stress.
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Affiliation(s)
- Wonsuk Yang
- Department of Integrative Biosciences, Texas A&M University, College Station, Texas 77843, USA
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26
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Lang W, Caldwell GW, Masucci JA. Evaluation of the effect of oxygen exposure on human liver microsomal metabolism of mitomycin C in the presence of glutathione using liquid chromatography-quadrupole time of flight mass spectrometry. Anal Biochem 2005; 343:268-76. [PMID: 16005424 DOI: 10.1016/j.ab.2005.05.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Revised: 05/12/2005] [Accepted: 05/27/2005] [Indexed: 11/21/2022]
Abstract
This article describes a metabolite profiling method for evaluating the effect of oxygen exposure on human liver microsomal metabolism of mitomycin C (MC) in the presence of glutathione (GSH) and NADPH under hypoxic (100% helium), limitedly and fully aerobic, and hyperoxic (100% oxygen) conditions. MC and its metabolite(s) were characterized and the relative percentages of these components were estimated at different incubation times using liquid chromatography and quadrupole time-of-flight mass spectrometry. The MC metabolite profiles were confirmed using purified human cytochrome P450 reductase, acidic activation, and UV-Vis detection at 550 nm. In hypoxia, MC was exclusively metabolized into 2,7-diaminomitosene-10-glutathione-S-conjugate (2,7-DAM-10-SG) within 30 min, whereas approximately 5% of this conjugate, 16% of 2,7-diaminomitosene (2,7-DAM), and 77% of MC were observed under a fully aerobic condition at 90 min. Under limitedly aerobic conditions, the relative percentages of the two metabolites in incubations varied greatly depending on the volume ratio of air to liquid. In hyperoxia, 2% of 2,7-DAM-10-SG, 9% of 2,7-DAM, and 86% of MC were obtained at 90 min. The results indicate that oxygen strongly inhibits the in vitro metabolism of MC. These data suggest that GSH may serve a dual function in facilitating the formation of a leucoaziridinomitosene followed by electron rearrangement giving intermediate metabolite 2,7-DAM, and then trapping this intermediate giving rise to 2,7-DAM-10-SG. These findings provide direct evidence for understanding the fate of oxygen-sensitive metabolic deactivation of MC by GSH.
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Affiliation(s)
- Wensheng Lang
- Johnson & Johnson Pharmaceutical Research and Development, Welsh and McKean Roads, Spring House, PA 19477, USA.
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27
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Geng H, Meng Z, Zhang Q. Effects of blowing sand fine particles on plasma membrane permeability and fluidity, and intracellular calcium levels of rat alveolar macrophages. Toxicol Lett 2005; 157:129-37. [PMID: 15837000 DOI: 10.1016/j.toxlet.2005.01.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Revised: 01/21/2005] [Accepted: 01/21/2005] [Indexed: 11/27/2022]
Abstract
Ambient fine particulate matter (PM2.5, particulates with an aerodynamic diameter < or = 2.5 microm) can suppress alveolar macrophage (AM) functions, but the data concerning the effects of blowing sand PM2.5 on AMs remain limited. The aim of the present study is to investigate the influences of blowing sand PM2.5 on AM plasma membranes and intracellular calcium ion concentration ([Ca2+]i), and explore the mechanisms of the observed toxicological effects. The samples of normal PM2.5 (collected on sunshiny and non-blowing sand days) and blowing sand PM2.5 were collected in Wuwei city, Gansu Province, China. After AMs from rat bronchoalveolar lavage fluid (BALF) were treated in vitro for 4 h with the suspensions of these samples, the cell viability, plasma membrane permeability and fluidity, cytosolic free Ca2+ levels, and oxidative stress were examined. It was observed a dose-dependent decrease in cell viability, plasma membrane Ca2+Mg2+-dependent adenosinetriphosphatase (Ca2+Mg2+-ATPase) and Na+K+-dependent adenosinetriphosphatase (Na+K+-ATPase) activities, cellular glutathione (GSH) levels, fluorescence intensities of lipid probe 8-anilino-1-naphthalene-sulfonic acid (ANS) and fluorescence polarization of lipid probe 1,6-diphenyl-1,3,5-hexatriene (DPH) combined with cell membranes in the treatment groups of normal and blowing sand PM2.5 as compared to the control (saline group); and also observed a dose-dependent increase in the leakage of lactate dehydrogenase (LDH) and acid phosphatase (ACP), and intracellular [Ca2+]i and malondialdehyde (MDA) levels. These observations indicate blowing sand PM2.5, as similar to urban normal ones, could induce oxidative stress on AMs, enlarge plasma membrane permeability and membrane lipid fluidity, and elevate intracellular [Ca2+]i levels, resulting in cytotoxicity. A two-way ANOVA showed the toxic effects of normal and blowing sand PM2.5 on AMs were only relative to treatment dosages but not to dust types, suggesting the blowing sand PM2.5 whose airborne mass concentrations were much higher should be more harmful.
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Affiliation(s)
- Hong Geng
- Institute of Environmental Medicine and Toxicology, Shanxi University, Wucheng Road 36, Taiyuan 030006, PR China.
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28
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Han YS, Kim JM, Cho JS, Lee CS, Kim DE. Comparison of the Protective Effect of Indole beta-carbolines and R-(-)-deprenyl Against Nitrogen Species-Induced Cell Death in Experimental Culture Model of Parkinson's Disease. J Clin Neurol 2005; 1:81-91. [PMID: 20396475 PMCID: PMC2854935 DOI: 10.3988/jcn.2005.1.1.81] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Accepted: 02/07/2005] [Indexed: 11/17/2022] Open
Abstract
Background The membrane permeability transition of mitochondria has been suggested to be involved in toxic and oxidative forms of cell injury. Mitochondrial dysfunction is considered to play a critical role in neurodegeneration in Parkinson's disease. Despite the suggestion that indole β-carbolines may be neurotoxic, these compounds provide a protective effect against cytotoxicity of other neurotoxins. In addition, the effect of indole β-carbolines on change in the mitochondrial membrane permeability due to reactive nitrogen species (RNS), which may lead to cell death, has not been clarified. Methods Differentiated PC12 cells were used as the experimental culture model for the investigation of neuronal cell injury, which occurs in Parkinson's disease. The effect of indole β-carbolines (harmalol and harmine) on differentiated PC12 cells against toxicity of S-nitroso-N-acetyl-DL-penicillamine (SNAP) was determined by measuring the effect on the change in transmembrane potential, cytochrome c release, formation of ROS, GSH contents, caspase-3 activity and cell viability, and was compared to that of R-(-)-deprenyl. Results Specific inhibitors of caspases (z-LEHD.fmk, z-DQMD.fmk) and antioxidants (N-acetylcysteine, dithiothreitol, melatonin, carboxy-PTIO and uric acid) depressed cell death in PC12 cells due to SNAP. β-Carbolines and R-(-)-deprenyl attenuated the SNAP-induced cell death and GSH depletion concentration dependently with a maximal inhibitory effect at 25-50 µM. The compounds inhibited the nuclear damage, decrease in mitochondrial transmembrane potential, cytochrome c release and formation of reactive oxygen species caused by SNAP in PC12 cells. β-Carbolines and R-(-)-deprenyl attenuated the H2O2-induced cell death and depletion of GSH. Conclusions The results suggest that indole β-carbolines attenuate the SNAP-induced viability loss in PC12 cells by inhibition of change in the mitochondrial membrane permeability, which may be caused by free radicals. Indole β-carbolines appear to exert a protective effect against the nitrogen species-mediated neuronal cell injury in Parkinson's disease comparable to R-(-)-deprenyl.
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Affiliation(s)
- Young-Su Han
- Department of Neurology, Seoul Veterans Hospital, Seoul, Korea
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Hsu M, Srinivas B, Kumar J, Subramanian R, Andersen J. Glutathione depletion resulting in selective mitochondrial complex I inhibition in dopaminergic cells is via an NO-mediated pathway not involving peroxynitrite: implications for Parkinson's disease. J Neurochem 2005; 92:1091-103. [PMID: 15715660 DOI: 10.1111/j.1471-4159.2004.02929.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
An early biochemical change in the Parkinsonian substantia nigra (SN) is reduction in total glutathione (GSH + GSSG) levels in affected dopaminergic neurons prior to depletion in mitochondrial complex I activity, dopamine loss, and cell death. We have demonstrated using dopaminergic PC12 cell lines genetically engineered to inducibly down-regulate glutathione synthesis that total glutathione depletion in these cells results in selective complex I inhibition via a reversible thiol oxidation event. Here, we demonstrate that inhibition of complex I may occur either by direct nitric oxide (NO) but not peroxinitrite-mediated inhibition of complex I or through H2O2-mediated inhibition of the tricarboxylic acid (TCA) cycle enzyme alpha-ketoglutarate dehydrogenase (KGDH) which supplies NADH as substrate to the complex; activity of both enzymes are reduced in PD. While glutathione depletion causes a reduction in spare KGDH enzymatic capacity, it produces a complete collapse of complex I reserves and significant effects on mitochondrial function. Our data suggest that NO is likely the primary agent involved in preferential complex I inhibition following acute glutathione depletion in dopaminergic cells. This may have major implications in terms of understanding mechanisms of dopamine cell death associated with PD especially as they relate to complex I inhibition.
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Affiliation(s)
- Michael Hsu
- Department of Molecular Biology, University of Southern California, Los Angeles, California, USA
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Chen C, Pung D, Leong V, Hebbar V, Shen G, Nair S, Li W, Kong ANT. Induction of detoxifying enzymes by garlic organosulfur compounds through transcription factor Nrf2: effect of chemical structure and stress signals. Free Radic Biol Med 2004; 37:1578-90. [PMID: 15477009 DOI: 10.1016/j.freeradbiomed.2004.07.021] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2004] [Revised: 06/22/2004] [Accepted: 07/15/2004] [Indexed: 12/24/2022]
Abstract
Garlic organosulfur compounds (OSCs) are recognized as a group of potential chemopreventive compounds. It is known that garlic OSCs can modulate drug metabolism systems, especially various phase II detoxifying enzymes, though the mechanism underlying their inductive effect on these enzymes remains largely unknown. In the present study, we investigated the transcriptional levels of NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO1) genes, the reporter activity mediated by antioxidant response element (ARE), and the protein level of transcription factor nuclear factor E2-related factor 2 (Nrf2), after administration of three major garlic OSCs--diallyl sulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS)--in human hepatoma HepG2 cells. Our results showed that ARE activation and Nrf2 protein accumulation were well correlated with phase II gene expression induction. The structure-activity relationship study indicated that the third sulfur in the structure of OSCs contributed substantially to their bioactivities, and that allyl-containing OSCs were more potent than propyl-containing OSCs. To better understand the signaling events involved in the upregulation of detoxifying enzymes by DATS, ARE activity and Nrf2 protein levels were examined after transient transfection of HepG2 cells with mutant Nrf2, cotreatment with antioxidants, and pretreatment with protein kinase inhibitors. DATS-induced ARE activity was inhibited by dominant-negative Nrf2 Kelch-like ECH-associating protein 1 and constructs. Cotreatment with thiol antioxidants decreased the ARE activity and Nrf2 protein level induced by DATS. Three major mitogen-activated protein kinases (MAPKs)--extracellular signal-regulated protein kinase, c-Jun N-terminal kinase, and p38--were activated by DATS treatment. However, the inhibition of these MAPKs did not affect DATS-induced ARE activity. Pretreatment with various upstream protein kinase inhibitors showed that the protein kinase C pathway was not directly involved in DATS-induced ARE activity, but instead the calcium-dependent signaling pathway appeared to play a role in the DATS-induced cytoprotective effect.
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Affiliation(s)
- Chi Chen
- Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
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Lee CS, Park SY, Ko HH, Han ES. Effect of change in cellular GSH levels on mitochondrial damage and cell viability loss due to mitomycin c in small cell lung cancer cells. Biochem Pharmacol 2004; 68:1857-67. [PMID: 15450951 DOI: 10.1016/j.bcp.2004.06.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2004] [Accepted: 06/14/2004] [Indexed: 11/26/2022]
Abstract
The effect of GSH depletion on mitochondrial damage and cell death due to mitomycin c (MMC) was assessed in small cell lung cancer (SCLC) cells. Cytotoxicity of MMC was attenuated by Tempol and dicumarol, inhibitors of the enzymatic reduction, and increased by xanthine oxidase. The MMC-induced cell death and decrease in the GSH contents in SCLC cells were inhibited by caspase inhibitors (z-DQMD.fmk, z-IETD.fmk and z-LEHD.fmk) and antioxidants (N-acetylcysteine, dithiothreitol and N-(2-mercaptopropionyl)glycine, melatonin, rutin and carboxy-PTIO). Thiol compounds, melatonin and rutin attenuated the MMC-induced nuclear damage, decrease in mitochondrial transmembrane potential, release of cytochrome c and activation of caspase-3. Treatment of MMC caused a significant decrease in GSH contents in SCLC cells, which was followed by increase in the formation of reactive oxygen species. Depletion of GSH due to L-buthionine sulfoximine enhanced the MMC-induced activation of caspase-3 and cell death in SCLC cells. Antioxidants, including N-acetylcysteine, depressed formations of nitric oxide, malondialdehyde and carbonyls due to MMC in SCLC cells. The results show that the reductive activation of MMC may cause cell death in SCLC cells by inducing mitochondrial dysfunction, leading to caspase-3 activation, and by activation of caspase-8. The MMC-induced change in the mitochondrial membrane permeability, followed by cell death, in SCLC cells may be significantly enhanced by decrease in the intracellular GSH contents due to oxidative attack of free radicals.
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Affiliation(s)
- Chung Soo Lee
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul 156-756, South Korea.
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Doroshenko N, Doroshenko P. The glutathione reductase inhibitor carmustine induces an influx of Ca2+ in PC12 cells. Eur J Pharmacol 2004; 497:17-24. [PMID: 15321730 DOI: 10.1016/j.ejphar.2004.06.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Revised: 06/18/2004] [Accepted: 06/22/2004] [Indexed: 11/24/2022]
Abstract
We studied the effects of carmustine (1,3-bis(2-chloroethyl)-1-nitrosourea) on the intracellular Ca(2+) concentration ([Ca(2+)](i)) in PC12 cells using fura-2 fluorescence imaging. Carmustine (100 microM) caused a delayed increase in [Ca(2+)](i) that developed within approximately 3 h. This effect was enhanced in cells that were pretreated with an inhibitor of glutathione (GSH) synthesis, buthionine sulfoximine (BSO, 200 microM, 24 h), and was suppressed in cells that were treated with an antioxidant deferoxamine (50 microM). The carmustine-induced increase in [Ca(2+)](i) was absolutely dependent on the presence of extracellular Ca(2+) and could be inhibited by dihydropyridine blockers of L-type voltage-gated Ca(2+) channels (nimodipine or nitrendipine, 10 microM). The increase in [Ca(2+)](i) was also suppressed in Cl(-)-free solution and in the presence of the Cl(-) channel blockers, indanyloxyacetic acid 94 (IAA-94, 100 microM) and 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, 100 microM). The inhibition was complete when the blockers were applied simultaneously with carmustine and was partial when the blockers were applied after the initial increase in [Ca(2+)](i). We conclude that carmustine induces an influx of extracellular Ca(2+) through L-type Ca(2+) channels and that this effect is mediated by oxidative stress that results from the depletion of GSH following the inhibition by carmustine of glutathione reductase.
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Affiliation(s)
- Nina Doroshenko
- Ottawa Health Research Institute, 725 Parkdale Avenue, Ottawa, Ontario K1Y 4E9, Canada
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Mao W, Qin F, Iwai C, Vulapalli R, Keng PC, Liang CS. Extracellular norepinephrine reduces neuronal uptake of norepinephrine by oxidative stress in PC12 cells. Am J Physiol Heart Circ Physiol 2004; 287:H29-39. [PMID: 14962827 DOI: 10.1152/ajpheart.01168.2003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiac norepinephrine (NE) uptake activity is reduced in congestive heart failure. Our studies in intact animals suggest that this effect on the cardiac sympathetic nerve endings is caused by oxidative stress and/or NE toxic metabolites derived from NE. In this study, we investigated the direct effects of NE on neuronal NE uptake activity and NE transporter (NET), using undifferentiated PC12 cells. Cells were incubated with NE (1–500 μM) either alone or in combination of Cu2+ sulfate (1 μM), which promotes free radical formation by Fenton reaction for 24 h. NE uptake activity was measured using [3H]NE. Cell viability was determined with the use of Trypan blue exclusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay, and cellular oxidative stress by dichlorodihydrofluorescein fluorescence and the GSH/GSSG ratio. Cell viability was reduced by NE >100 μM. At lower doses, NE produced oxidative stress and a dose-dependent reduction of NE uptake activity without affecting cell viability significantly. Cu2+, which has no direct effect on NE uptake activity, potentiated oxidative stress and reduction of NE uptake activity produced by NE. This decrease of NE uptake activity was associated with reductions of NE uptake binding sites and NET protein expression by using the radioligand assay and Western blot analysis, but no changes in NET gene expression. In addition, the free-radical scavenger mannitol, and antioxidant enzymes superoxide dismutase and catalase, reduced oxidative stress and attenuated the reductions of NE uptake activity and NET protein produced by NE/Cu. Thus our results support a functional role of oxidative stress in mediating the neuronal NE uptake reducing effect of NE and that this effect of NE on NET is a posttranscriptional event.
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Affiliation(s)
- Weike Mao
- University of Rochester Medical Center, Cardiology Unit, Box 679, 601 Elmwood Ave., Rochester, NY 14642, USA
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Lee CS, Han ES, Lee WB. Antioxidant effect of phenelzine on MPP+-induced cell viability loss in differentiated PC12 cells. Neurochem Res 2004; 28:1833-41. [PMID: 14649725 DOI: 10.1023/a:1026119708124] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Phenelzine, deprenyl, and antioxidants (SOD, catalase, ascorbate, or rutin) reduced the loss of cell viability in differentiated PC12 cells treated with 250 microM MPP+, whereas N-acetylcysteine and dithiothreitol did not inhibit cell death. Phenelzine reduced the condensation and fragmentation of nuclei caused by MPP+ in PC12 cells. Phenelzine and deprenyl prevented the MPP+-induced decrease in mitochondrial membrane potential, cytochrome c release, formation of reactive oxygen species, and depletion of GSH in PC12 cells. Phenelzine revealed a scavenging action on hydrogen peroxide and reduced the hydrogen peroxide-induced cell death in PC12 cells, whereas deprenyl did not depress the cytotoxic effect of hydrogen peroxide. Both compounds reduced the iron and EDTA-mediated degradation of 2-deoxy-D-ribose degradation. The results suggest that phenelzine attenuates the MPP+-induced viability loss in PC12 cells by reducing the alteration of mitochondrial membrane permeability that seems to be mediated by oxidative stress.
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Affiliation(s)
- Chung Soo Lee
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, South Korea.
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35
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Hong JS, Ko HH, Han ES, Lee CS. Inhibition of bleomycin-induced cell death in rat alveolar macrophages and human lung epithelial cells by ambroxol. Biochem Pharmacol 2003; 66:1297-306. [PMID: 14505809 DOI: 10.1016/s0006-2952(03)00448-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mitochondrial permeability transition is recognized to be involved in toxic and oxidative forms of cell injury. In the present study, we investigated the effect of ambroxol against the cytotoxicity of bleomycin (BLM) by looking at the effect on the mitochondrial membrane permeability in alveolar macrophages and lung epithelial cells. Alveolar macrophages or lung epithelial cells exposed to BLM revealed the loss of cell viability and increase in caspase-3 activity. Ambroxol (10-100 microM) reduced the 75 mU/mL BLM-induced cell death and activation of caspase-3 in macrophages or epithelial cells. It reduced the condensation and fragmentation of nuclei caused by BLM in macrophages. Ambroxol alone did not significantly cause cell death. Treatment of alveolar macrophages with BLM resulted in the decrease in transmembrane potential in mitochondria, cytosolic accumulation of cytochrome c, increase in formation of reactive oxygen species (ROS) and depletion of GSH. Ambroxol (10-100 microM) inhibited the increase in mitochondrial membrane permeability, ROS formation and decrease in GSH contents due to BLM in macrophages. Ambroxol exerted a scavenging effect on hydroxyl radicals and nitric oxide and reduced the iron-mediated formation of malondialdehyde and carbonyls in liver mitochondria. It prevented cell death due to SIN-1 in lung epithelial cells. The results demonstrate that ambroxol attenuates the BLM-induced viability loss in alveolar macrophages or lung epithelial cells. This effect may be due to inhibition of mitochondrial damage and due to the scavenging action on free radicals.
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Affiliation(s)
- Jun Sik Hong
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul 156-756, South Korea
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36
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Lee CS, Song EH, Park SY, Han ES. Combined effect of dopamine and MPP+ on membrane permeability in mitochondria and cell viability in PC12 cells. Neurochem Int 2003; 43:147-54. [PMID: 12620283 DOI: 10.1016/s0197-0186(02)00214-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present study examined the combined effect of dopamine and 1-methyl-4-phenylpyridinium (MPP(+)) on the membrane permeability in isolated brain mitochondria and on cell viability in PC12 cells. MPP(+) increased effect of dopamine against the swelling, membrane potential, and Ca(2+) transport in isolated mitochondria, which was not inhibited by the addition of antioxidant enzymes (SOD and catalase). Dopamine or MPP(+) caused the decrease in transmembrane potential, increase in reactive oxygen species, depletion of GSH, and cell death in PC12 cells. Antioxidant enzymes reduced each effect of dopamine and MPP(+) against PC12 cells. Co-addition of dopamine and MPP(+) caused the decrease in the transmembrane potential and increase in the formation of reactive oxygen species in PC12 cells, in which they showed an additive effect. Dopamine plus MPP(+)-induced the depletion of GSH and cell death in PC12 cells were not decreased by the addition of antioxidant enzymes, rutin, diethylstilbestrol, and ascorbate. Melanin caused a cell viability loss in PC12 cells. The N-acetylcysteine, N-phenylthiourea, and 5-hydroxyindole decreased the cell death and the formation of dopamine quinone and melanin induced by co-addition of dopamine and MPP(+), whereas deprenyl and chlorgyline did not show an inhibitory effect. The results suggest that co-addition of dopamine and MPP(+) shows an enhancing effect on the change in mitochondrial membrane permeability and cell death, which may be accomplished by toxic quinone and melanin derived from the MPP(+)-stimulated dopamine oxidation.
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Affiliation(s)
- Chung Soo Lee
- Department of Pharmacology, College of Medicine, Chung-Ang University, 156-756, Seoul, South Korea.
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37
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Park TH, Kwon OS, Park SY, Han ES, Lee CS. N-methylated beta-carbolines protect PC12 cells from cytotoxic effect of MPP+ by attenuation of mitochondrial membrane permeability change. Neurosci Res 2003; 46:349-58. [PMID: 12804796 DOI: 10.1016/s0168-0102(03)00097-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Opening of the mitochondrial permeability transition pore has been recognized to be involved in cell death. The present study investigated the effect of beta-carbolines (harmaline and harmalol) on the MPP(+)-induced change in the mitochondrial membrane permeability and cell death in differentiated PC12 cells. beta-Carbolines and antioxidants (superoxide dismutase, catalase, ascorbate or rutin) prevented the loss of cell viability in PC12 cells treated with 250 microM MPP(+), while the effects of N-acetylcysteine and dithiothreitol were not observed. beta-Carbolines reduced the condensation and fragmentation of nuclei caused by MPP(+) in PC12 cells. beta-Carbolines alone did not exhibit a significant cytotoxic effect on PC12 cells. beta-Carbolines (50 microM) inhibited the decrease in mitochondrial transmembrane potential, cytochrome c release, activation of caspase-3, formation of reactive oxygen species (ROS) and depletion of GSH caused by MPP(+) in PC12 cells. beta-Carbolines reduced the hydrogen peroxide- or SIN-1-induced cell death in PC12 cells. The results suggest that beta-carbolines may attenuate the MPP(+)-induced viability loss in PC12 cells by inhibition of change in the mitochondrial membrane permeability and by antioxidant effect.
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Affiliation(s)
- Tai Hwan Park
- Department of Neurology, College of Medicine, Chung-Ang University, 156-756, Seoul, South Korea
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38
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Nicholls DG. Mitochondrial function and dysfunction in the cell: its relevance to aging and aging-related disease. Int J Biochem Cell Biol 2002; 34:1372-81. [PMID: 12200032 DOI: 10.1016/s1357-2725(02)00077-8] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria plays a complex multi-factorial role in the cell. In addition to their primary role in ATP generation, the organelles sequester calcium and both generate and detoxify reactive oxygen species. All these functions are intimately inter-linked through the central bioenergetic parameter of the proton electrochemical gradient across the inner mitochondrial membrane. Subtle changes in respiratory chain capacity, substrate supply, glutathione levels, cytoplasmic calcium and membrane potential occur in aging and in conditions predisposing towards neurodegenerative disease. These interactions are incompletely understood and in this review I present an overview of some of the current research in this area, and its possible relevance to aging and aging-related disease.
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Abstract
Carnitine (4-N-trimethylammonium-3-hydroxybutyric acid) plays an important role in the translocation of acetyl moieties from the mitochondria into the cytoplasm for acetylcholine synthesis in the brain. Previous studies in our laboratory have shown that L-carnitine suppresses oxidative damage during aging. This study was carried out to see the effect of L-carnitine on the status of non-enzymatic antioxidants and lipofuscin accumulation in various regions of the aged rat brain. We observed a decrease in the status of ascorbic acid, glutathione and vitamin E in aged rats. Histological work showed that the accumulation of lipofuscin increased as a function of age. The extent of damage varied between the regions we have investigated. Supplementation of L-carnitine to aged rat improved the antioxidant status in a duration dependent manner. The accumulation of lipofuscin was also found to be decreased after L-carnitine administration. The data suggests that decrement of lipofuscin accumulation by L-carnitine may be partially due to its antioxidant promoting action.
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Affiliation(s)
- P J Arockia Rani
- Department of Medical Biochemistry, Dr. ALM PGIBMS, University of Madras, Taramani, Chennai 113, India.
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40
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Denisova NA, Cantuti-Castelvetri I, Hassan WN, Paulson KE, Joseph JA. Role of membrane lipids in regulation of vulnerability to oxidative stress in PC12 cells: implication for aging. Free Radic Biol Med 2001; 30:671-8. [PMID: 11295365 DOI: 10.1016/s0891-5849(00)00513-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Previously, we reported that PC12 cells showed increased vulnerability to oxidative stress (OS) induced by H2O2 (as assessed by decrements in calcium recovery, i.e., the ability of cells to buffer Ca(2+) after a depolarization event) when the membrane levels of cholesterol (CHL) and sphingomyelin (SPH) were modified to approximate those seen in the neuronal membranes of old animals. The present study was designed to examine whether the enrichment of the membranes with SPH-CHL and increased cellular vulnerability to OS are mediated by neutral SPH-specific phospholipase C (N-Sase) and the intracellular antioxidant GSH. The results showed a significant up-regulation of N-Sase activity by both low (5 microM) and high (300 microM) doses of H2O2. However, under high doses of H2O2 the up-regulation of N-Sase is accompanied by a significant increase in reactive oxygen species and by a decrease in intracellular GSH. The enrichment of membranes with SPH-CHL significantly potentiated the effects of high doses of H2O2, by further reducing the intracellular GSH and further up-regulating the N-Sase activity. Furthermore, repleting intracellular GSH with 20 mM N-acetylcysteine treatment was sufficient to attenuate the effect of a low dose of H2O2 on Ca(2+) recovery in SPH-CHL-treated cells. Thus, these results suggested that age-related alterations in the membrane SPH-CHL levels could be important determinants of the susceptibility of neuronal cells to OS.
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Affiliation(s)
- N A Denisova
- United States Department of Agriculture, Jean Mayer Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
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41
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Pereira CF, Oliveira CR. Oxidative glutamate toxicity involves mitochondrial dysfunction and perturbation of intracellular Ca2+ homeostasis. Neurosci Res 2000; 37:227-36. [PMID: 10940457 DOI: 10.1016/s0168-0102(00)00124-3] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glutamate toxicity on PC12 cells is mediated by oxidative stress as a consequence of the inhibition of a cystine uptake system with depletion of GSH. In this study we report that glutamate decreases PC12 cell viability, inhibiting the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). This decrease was prevented by the antioxidants vitamin E, idebenone and L-deprenyl, which were also shown to be effective in reducing the accumulation of reactive oxygen species (ROS) in cells exposed to glutamate, decreasing the fluorescence of 2',7'-dichlorofluorescein (DCF). Incubation of PC12 cells with high glutamate concentrations induced mitochondrial dysfunction, leading to the loss of mitochondrial transmembrane potential, evaluated as a decrease in rhodamine 123 (Rh123) retention by mitochondria, and to the decrease of intracellular ATP levels. The mitochondrial dysfunction, induced by glutamate, can be involved in the observed increase of [Ca2+]i. The elevation of [Ca2+]i occurred after GSH depletion, suggesting that oxidative stress is involved in the disturbances of intracellular calcium homeostasis. In conclusion, our data indicate that glutamate, at concentrations which block cystine uptake in PC12 cells leading to GSH depletion and inducing oxidative stress, increases ROS accumulation and decreases cell survival by a mechanism involving mitochondrial dysfunction and impairment of Ca2+ homeostasis.
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Affiliation(s)
- C F Pereira
- Faculty of Medicine and Center for Neuroscience of Coimbra, University of Coimbra, Portugal.
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42
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Sen CK, Khanna S, Roy S, Packer L. Molecular basis of vitamin E action. Tocotrienol potently inhibits glutamate-induced pp60(c-Src) kinase activation and death of HT4 neuronal cells. J Biol Chem 2000; 275:13049-55. [PMID: 10777609 DOI: 10.1074/jbc.275.17.13049] [Citation(s) in RCA: 240] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
HT4 hippocampal neuronal cells were studied to compare the efficacy of tocopherols and tocotrienol to protect against glutamate-induced death. Tocotrienols were more effective than alpha-tocopherol in preventing glutamate-induced death. Uptake of tocotrienols from the culture medium was more efficient compared with that of alpha-tocopherol. Vitamin E molecules have potent antioxidant properties. Results show that at low concentrations, tocotrienols may have protected cells by an antioxidant-independent mechanism. Examination of signal transduction pathways revealed that protein tyrosine phosphorylation processes played a central role in the execution of death. Activation of pp60(c-Src) kinase and phosphorylation of ERK were observed in response to glutamate treatment. Nanomolar amounts of alpha-tocotrienol, but not alpha-tocopherol, blocked glutamate-induced death by suppressing glutamate-induced early activation of c-Src kinase. Overexpression of kinase-active c-Src sensitized cells to glutamate-induced death. Tocotrienol treatment prevented death of Src-overexpressing cells treated with glutamate. alpha-Tocotrienol did not influence activity of recombinant c-Src kinase suggesting that its mechanism of action may include regulation of SH domains. This study provides first evidence describing the molecular basis of tocotrienol action. At a concentration 4-10-fold lower than levels detected in plasma of supplemented humans, tocotrienol regulated unique signal transduction processes that were not sensitive to comparable concentrations of tocopherol.
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Affiliation(s)
- C K Sen
- Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA.
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43
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Mice deficient in cellular glutathione peroxidase show increased vulnerability to malonate, 3-nitropropionic acid, and 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine. J Neurosci 2000. [PMID: 10627575 DOI: 10.1523/jneurosci.20-01-00001.2000] [Citation(s) in RCA: 248] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Glutathione peroxidase (GSHPx) is a critical intracellular enzyme involved in detoxification of hydrogen peroxide (H(2)O(2)) to water. In the present study we examined the susceptibility of mice with a disruption of the glutathione peroxidase gene to the neurotoxic effects of malonate, 3-nitropropionic acid (3-NP), and 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). Glutathione peroxidase knock-out mice showed no evidence of neuropathological or behavioral abnormalities at 2-3 months of age. Intrastriatal injections of malonate resulted in a significant twofold increase in lesion volume in homozygote GSHPx knock-out mice as compared to both heterozygote GSHPx knock-out and wild-type control mice. Malonate-induced increases in conversion of salicylate to 2,3- and 2, 5-dihydroxybenzoic acid, an index of hydroxyl radical generation, were greater in homozygote GSHPx knock-out mice as compared with both heterozygote GSHPx knock-out and wild-type control mice. Administration of MPTP resulted in significantly greater depletions of dopamine, 3,4-dihydroxybenzoic acid, and homovanillic acid in GSHPx knock-out mice than those seen in wild-type control mice. Striatal 3-nitrotyrosine (3-NT) concentrations after MPTP were significantly increased in GSHPx knock-out mice as compared with wild-type control mice. Systemic 3-NP administration resulted in significantly greater striatal damage and increases in 3-NT in GSHPx knock-out mice as compared to wild-type control mice. The present results indicate that a knock-out of GSHPx may be adequately compensated under nonstressed conditions, but that after administration of mitochondrial toxins GSHPx plays an important role in detoxifying increases in oxygen radicals.
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44
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Kang Y, Viswanath V, Jha N, Qiao X, Mo JQ, Andersen JK. Brain γ-glutamyl cysteine synthetase (GCS) mRNA expression patterns correlate with regional-specific enzyme activities and glutathione levels. J Neurosci Res 1999. [DOI: 10.1002/(sici)1097-4547(19991101)58:3<436::aid-jnr9>3.0.co;2-b] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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45
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Su JY, Duffy S, Murphy TH. Reduction of H2O2-evoked, intracellular calcium increases in the rat N18-RE-105 neuronal cell line by pretreatment with an electrophilic antioxidant inducer. Neurosci Lett 1999; 273:109-12. [PMID: 10505628 DOI: 10.1016/s0304-3940(99)00634-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pretreatment of the neuronal cell line N18-RE-105 with the antioxidant enzyme inducer dimethyl fumarate (DMF) reduced cell death elicited by H2O2 (50 mM for 1 h) as measured 24 h after H2O2 washout. Oxidants like H2O2 may contribute to cell death by increasing intracellular ionized calcium ([Ca2+]i), suggesting that DMF may in part confer protection by altering H2O2-induced [Ca2+]i signals. To examine this possibility, we measured [Ca2+]i of fura-2-loaded cultures of DMF- and vehicle-pretreated cells during H2O2 superfusion. H2O2 exposure induced a delayed [Ca2+]i increase that was significantly lower in DMF-pretreated cells than controls. Elevation of extracellular cystine also reduced the H2O2 induced [Ca2+]i elevation. Thus, antioxidant upregulation may contribute to protection during oxidative stress by stabilizing [Ca2+]i. However, since oxidative stress may induce cytotoxicity by multiple pathways, [Ca2+]i stabilization may not be the only mechanism responsible for the protective effect of DMF.
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Affiliation(s)
- J Y Su
- Department of Psychiatry University of British Columbia, Vancouver, Canada
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46
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Koppal T, Drake J, Yatin S, Jordan B, Varadarajan S, Bettenhausen L, Butterfield DA. Peroxynitrite-induced alterations in synaptosomal membrane proteins: insight into oxidative stress in Alzheimer's disease. J Neurochem 1999; 72:310-7. [PMID: 9886083 DOI: 10.1046/j.1471-4159.1999.0720310.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Peroxynitrite (ONOO ) is a highly reactive, oxidizing anion with a half-life of <1 s that is formed by reaction of superoxide radical anion with nitric oxide. Several reports of ONOO--induced oxidation of lipids, proteins, DNA, sulfhydryls, and inactivation of key enzymes have appeared. ONOO- has also been implicated as playing a role in the pathology of several neurodegenerative disorders, such as Alzheimer's disease (AD) and amyotrophic lateral sclerosis, among others. Continuing our laboratory's interest in free radical oxidative stress in brain cells in AD, the present study was designed to investigate the damage to brain neocortical synaptosomal membrane proteins and the oxidation-sensitive enzyme glutamine synthetase (GS) caused by exposure to ONOO-. These synaptosomal proteins and GS have previously been shown by us and others to have been oxidatively damaged in AD brain and also following treatment of synaptosomes with amyloid beta-peptide. The results of the current study showed that exposure to physiological levels of ONOO- induced significant protein conformational changes, demonstrated using electron paramagnetic resonance in conjunction with a protein-specific spin label, and caused oxidation of proteins, measured by the increase in protein carbonyls. ONOO- also caused inactivation of GS and led to neuronal cell death examined in a hippocampal cell culture system. All these detrimental effects of ONOO- were successfully attenuated by the thiol-containing antioxidant tripeptide glutathione. This research shows that ONOO- can oxidatively modify both membranous and cytosolic proteins, affecting both their physical and chemical nature. These findings are discussed with reference to the potential involvement of ONOO- in AD neurodegeneration.
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Affiliation(s)
- T Koppal
- Department of Chemistry, Center of Membrane Sciences, University of Kentucky, Lexington 40506-0055, USA
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47
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Li Y, Copin JC, Reola LF, Calagui B, Gobbel GT, Chen SF, Sato S, Epstein CJ, Chan PH. Reduced mitochondrial manganese-superoxide dismutase activity exacerbates glutamate toxicity in cultured mouse cortical neurons. Brain Res 1998; 814:164-70. [PMID: 9838093 DOI: 10.1016/s0006-8993(98)01082-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Studies of neuronal injury and death after cerebral ischemia and various neurodegenerative diseases have increasingly focused on the interactions between mitochondrial function, reactive oxygen species (ROS) production and glutamate neurotoxicity. Recent findings suggest that increased mitochondrial ROS production precedes neuronal death after glutamate treatment. It is hypothesized that under pathological conditions when mitochondrial function is compromised, extracellular glutamate may exacerbate neuronal injury. In the present study, we focus on the relationship between mitochondrial superoxide production and glutamate neurotoxicity in cultured cortical neurons with normal or reduced levels of manganese-superoxide dismutase (MnSOD) activity. Our results demonstrate that neurons with reduced MnSOD activity are significantly more sensitive to transient exposure to extracellular glutamate. The increased sensitivity of cultured cortical neurons with reduced MnSOD activity is characteristically subject only to treatment by glutamate but not to other glutamate receptor agonists, such as N-methyl-d-aspartate, kainate and quisqualate. We suggest that the reduced MnSOD activity in neurons may exacerbate glutamate neurotoxicity via a mechanism independent of receptor activation.
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Affiliation(s)
- Y Li
- Department of Neurological Surgery, University of California, School of Medicine, San Francisco, CA 94143-0651, USA
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48
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Cardoso SM, Pereira C, Oliveira CR. The protective effect of vitamin E, idebenone and reduced glutathione on free radical mediated injury in rat brain synaptosomes. Biochem Biophys Res Commun 1998; 246:703-10. [PMID: 9618276 DOI: 10.1006/bbrc.1998.8563] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the present study the effect of ascorbate (0.8 mM)/iron (2.5 microM) on lipid and protein oxidation, in Synaptosomes isolated from rat brain cortex, was evaluated. Vitamin E, idebenone and reduced glutathione were used as free radicals scavengers, in order to analyze the mechanism involved in ascorbate/iron-induced oxidative stress. An increased formation of reactive oxygen species (ROS) in the cytosol and in the mitochondria was observed, in ascorbate/iron treated synaptosomes. Idebenone (50 microM) prevented the increased formation of ROS in both synaptosomal compartments, vitamin E (150 microM) protected partially this formation in mitochondria, whereas reduced glutathione (250 microM) (GSH) was ineffective. After ascorbate/iron treatment an increase in lipid peroxidation occurred as compared to control, which was completely inhibited by idebenone. A decrease in protein-SH content was also observed, and it was prevented by Vitamin E, idebenone and GSH. When synaptosomes were treated with ascorbate/iron the levels of GSH decreased, and the levels of oxidized glutathione (GSSG) increased as compared to controls under these conditions. Glutathione peroxidase activity was unchanged, whereas an inhibition of glutathione reductase activity was observed. These data suggest that the increased formation of free radicals in synaptosomes leads to lipid and protein oxidation, the role of the endogenous GSH being essential to protect protein thiol-groups against oxidative damage in order to maintain enzyme activity.
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Affiliation(s)
- S M Cardoso
- Center for Neuroscience of Coimbra, University of Coimbra, Portugal
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