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Das R, Karri R, Chalana A, Rai RK, Roy G. Uncovering the Role of Methylmercury on DNA Lesions at Cytotoxic Concentrations in Glutathione-Depleted Cells: Insights from Experimental and Computational Studies. Inorg Chem 2024; 63:10455-10465. [PMID: 38743433 DOI: 10.1021/acs.inorgchem.3c04579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Organomercurials (RHg+), especially methylmercury (MeHg+) and ethylmercury (EtHg+), are considered to be more neurotoxic than the inorganic counterpart (Hg2+). They cause massive DNA damage in cells, especially in neurons, where cellular glutathione (GSH) levels are significantly low. However, the mechanism by which RHg+ exerts massive DNA damage at cytotoxic concentrations in brain cells remains obscure. In this study, we investigated the effect of RHg+ on the structural and electronic properties of nucleosides and its effects on DNA damage. The direct interaction of RHg+ with the nucleoside significantly weakens N-glycosidic bonds, decreases the C-H bond energy of sugar moieties, and increases the electrophilicity of the C8-center of purine bases. As a consequence, RHg+-conjugated DNA molecules are extremely labile and highly sensitive to any nucleophiles/radicals present in GSH-depleted cells and, thus, undergo enhanced oxidative and unusual alkylative DNA damage. We also report a functional model of organomercurial lyase, which showed excellent cytoprotective effect against RHg+-induced cytotoxicity; this reverses the activity of glutathione reductase inhibited by MeHgCl and ceases oxidative and alkylating DNA damage. This intriguing finding provides new mechanistic insight into the mode of action of organomercurials in GSH-depleted cells and their adverse effects on individuals with neurodegenerative disorders associated with oxidative stress.
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Affiliation(s)
- Ranajit Das
- Department of Chemistry, School of Natural Sciences, Shiv Nadar Institution of Eminence Deemed to be University, Dadri, UP 201314, India
| | - Ramesh Karri
- Department of Chemistry, School of Natural Sciences, Shiv Nadar Institution of Eminence Deemed to be University, Dadri, UP 201314, India
- Ruhvenile Biomedical OPC Pvt. Ltd., New Delhi 110070, Delhi, India
| | - Ashish Chalana
- Centre for Development of Biomaterials, Department of Chemistry & Biochemistry, Sharda University, Greater Noida, UP 201306, India
| | - Rakesh Kumar Rai
- Department of Chemistry, Indian Institute of Technology Tirupati, Tirupati, AP 517619, India
| | - Gouriprasanna Roy
- Department of Chemistry, Indian Institute of Technology Tirupati, Tirupati, AP 517619, India
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Sousa T, Gouveia M, Travasso RD, Salvador A. How abundant are superoxide and hydrogen peroxide in the vasculature lumen, how far can they reach? Redox Biol 2022; 58:102527. [PMID: 36335761 PMCID: PMC9640316 DOI: 10.1016/j.redox.2022.102527] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/21/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022] Open
Abstract
Paracrine superoxide (O2•−) and hydrogen peroxide (H2O2) signaling critically depends on these substances' concentrations, half-lives and transport ranges in extracellular media. Here we estimated these parameters for the lumen of human capillaries, arterioles and arteries using reaction-diffusion-advection models. These models considered O2•− and H2O2 production by endothelial cells and uptake by erythrocytes and endothelial cells, O2•− dismutation, O2•− and H2O2 diffusion and advection by the blood flow. Results show that in this environment O2•− and H2O2 have half-lives <60. ms and <40. ms, respectively, the former determined by the plasma SOD3 activity, the latter by clearance by endothelial cells and erythrocytes. H2O2 concentrations do not exceed the 10 nM scale. Maximal O2•− concentrations near vessel walls exceed H2O2's several-fold when the latter results solely from O2•− dismutation. Cytosolic dismutation of inflowing O2•− may thus significantly contribute to H2O2 delivery to cells. O2•− concentrations near vessel walls decay to 50% of maximum 12 μm downstream from O2•− production sites. H2O2 concentrations in capillaries decay to 50% of maximum 22 μm (6.0 μm) downstream from O2•− (H2O2) production sites. Near arterioles' (arteries') walls, they decay by 50% within 6.0 μm (4. μm) of H2O2 production sites. However, they reach maximal values 50 μm (24 μm) downstream from O2•− production sites and decrease by 50% over 650 μm (500 μm). Arterial/olar endothelial cells might thus signal over a mm downstream through O2•−-derived H2O2, though this requires nM-sensitive H2O2 transduction mechanisms. Physiological local H2O2 concentrations in vasculature lumen are up to 10's of μM. H2O2 transport range in capillaries is just ≈20 μm. Faster blood flow in arteri(ol)es transports O2•−-derived H2O2 over 100's of μm Similar H2O2 abundances and distribution near arterioles' and arteries' walls, likewise for O2•−. Inflowing O2•− may significantly feed H2O2 to the cytosol of endothelial cells
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Bjørklund G, Zou L, Peana M, Chasapis CT, Hangan T, Lu J, Maes M. The Role of the Thioredoxin System in Brain Diseases. Antioxidants (Basel) 2022; 11:2161. [PMID: 36358532 PMCID: PMC9686621 DOI: 10.3390/antiox11112161] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/23/2022] [Accepted: 10/28/2022] [Indexed: 08/08/2023] Open
Abstract
The thioredoxin system, consisting of thioredoxin (Trx), thioredoxin reductase (TrxR), and NADPH, plays a fundamental role in the control of antioxidant defenses, cell proliferation, redox states, and apoptosis. Aberrations in the Trx system may lead to increased oxidative stress toxicity and neurodegenerative processes. This study reviews the role of the Trx system in the pathophysiology and treatment of Alzheimer's, Parkinson's and Huntington's diseases, brain stroke, and multiple sclerosis. Trx system plays an important role in the pathophysiology of those disorders via multiple interactions through oxidative stress, apoptotic, neuro-immune, and pro-survival pathways. Multiple aberrations in Trx and TrxR systems related to other redox systems and their multiple reciprocal relationships with the neurodegenerative, neuro-inflammatory, and neuro-oxidative pathways are here analyzed. Genetic and environmental factors (nutrition, metals, and toxins) may impact the function of the Trx system, thereby contributing to neuropsychiatric disease. Aberrations in the Trx and TrxR systems could be a promising drug target to prevent and treat neurodegenerative, neuro-inflammatory, neuro-oxidative stress processes, and related brain disorders.
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Affiliation(s)
- Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Toften 24, 8610 Mo i Rana, Norway
| | - Lili Zou
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, China
| | - Massimiliano Peana
- Department of Chemical, Physical, Mathematical and Natural Sciences, University of Sassari, Via Vienna 2, 07100 Sassari, Italy
| | - Christos T. Chasapis
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece
| | - Tony Hangan
- Faculty of Medicine, Ovidius University of Constanta, 900470 Constanta, Romania
| | - Jun Lu
- School of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Michael Maes
- Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand
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4
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Tong ZB, Kim H, El Touny L, Simeonov A, Gerhold D. LUHMES Dopaminergic Neurons Are Uniquely Susceptible to Ferroptosis. Neurotox Res 2022; 40:1526-1536. [PMID: 35922689 PMCID: PMC9576307 DOI: 10.1007/s12640-022-00538-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/13/2022] [Accepted: 06/27/2022] [Indexed: 02/07/2023]
Abstract
Ferroptosis is a necrotic cell death caused by lipid oxidation that may be responsible for neural degeneration in Parkinson's disease. We assessed whether three neuronal cell lines are sensitive to killing by ferroptosis. Ferroptosis inducer erastin killed LUHMES neurons at sub-micromolar concentrations, whereas neuronal cells derived from SH-SY5Y cells or neural stem cells were at least 50-fold less sensitive. LUHMES differentiated neurons were likewise sensitive to killing by RSL3 or ML210, inhibitors of the glutathione peroxidase 4 enzyme (GPX4) that consumes GSH to detoxify lipid peroxides. Additional assays showed that erastin, RSL3, and ML210 increased lipid peroxide levels, and that LUHMES neurons were protected from both peroxide accumulation and cell death by ferrostatin-1. A possible role of iron was assessed by evaluating the effects of five metal chelators on cytotoxicity of erastin and RSL3. LUHMES neurons were protected from RSL3 by three of the chelators, 2,3-dimercapto-1-propanesulfonic acid (DMPS), deferoxiprone (DFX), and deferiprone (DFP). Collectively, these results demonstrate the vulnerability of LUHMES neurons to ferroptosis by chemical treatments that disrupt glutathione synthesis, lipid peroxide detoxification, or iron metabolism. The same vulnerabilities may occur in CNS neurons, which reportedly generate low levels of GSH and metallothioneins, limiting their ability to neutralize oxidative stresses and toxic metals. These results suggest a rationale and methods to search for environmental toxicants that may exploit these vulnerabilities and promote neurodegenerative diseases.
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Affiliation(s)
- Zhi-Bin Tong
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, 20850, USA
| | - Hyunhee Kim
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, 20850, USA
| | - Lara El Touny
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, 20850, USA
| | - Anton Simeonov
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, 20850, USA
| | - David Gerhold
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, 20850, USA.
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Uraguchi S, Nagai K, Naruse F, Otsuka Y, Ohshiro Y, Nakamura R, Takanezawa Y, Kiyono M. Development of affinity bead-based in vitro metal-ligand binding assay reveals dominant cadmium affinity of thiol-rich small peptides phytochelatins beyond glutathione. Metallomics 2021; 13:6445037. [PMID: 34850059 DOI: 10.1093/mtomcs/mfab068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/17/2021] [Indexed: 11/12/2022]
Abstract
For a better understanding of metal-ligand interaction and its function in cells, we developed an easy, sensitive, and high-throughput method to quantify ligand-metal(loid) binding affinity under physiological conditions by combining ligand-attached affinity beads and inductively coupled plasma-optical emission spectrometry (ICP-OES). Glutathione (GSH) and two phytochelatins (PC2 and PC3, small peptides with different numbers of free thiols) were employed as model ligands and attached to hydrophilic beads. The principle of the assay resembles that of affinity purification of proteins in biochemistry: metals binding to the ligand on the beads and the rest in the buffer are separated by a spin column and quantified by ICP-OES. The binding assay using the GSH-attached beads and various metal(loid)s suggested the different affinity of the metal-GSH interactions, in accordance with the order of the Irving-Williams series and the reported stability constants. The binding assay using PC2 or PC3-attached beads suggested positive binding between PCs and Ni(II), Cu(II), Zn(II), Cd(II), and As(III) in accordance with the number of thiols in PC2 and PC3. We then conducted the competition assay using Cd(II), Mn(II), Fe(II), Cu(II), and Zn(II), and the results suggested a better binding affinity of PC2 with Cd(II) than with the essential metals. Another competition assay using PC2 and GSH suggested a robust binding affinity between PCs and Cd(II) compared to GSH and Cd(II). These results suggested the dominance of PC-Cd complex formation in vitro, supporting the physiological importance of PCs for the detoxification of cadmium in vivo. We also discuss the potential application of the assay.
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Affiliation(s)
- Shimpei Uraguchi
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Kenichiro Nagai
- Medicinal Research Laboratories, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Fumii Naruse
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Yuto Otsuka
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Yuka Ohshiro
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Ryosuke Nakamura
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Yasukazu Takanezawa
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Masako Kiyono
- Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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Haddad M, Hervé V, Ben Khedher MR, Rabanel JM, Ramassamy C. Glutathione: An Old and Small Molecule with Great Functions and New Applications in the Brain and in Alzheimer's Disease. Antioxid Redox Signal 2021; 35:270-292. [PMID: 33637005 DOI: 10.1089/ars.2020.8129] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Significance: Glutathione (GSH) represents the most abundant and the main antioxidant in the body with important functions in the brain related to Alzheimer's disease (AD). Recent Advances: Oxidative stress is one of the central mechanisms in AD. We and others have demonstrated the alteration of GSH levels in the AD brain, its important role in the detoxification of advanced glycation end-products and of acrolein, a by-product of lipid peroxidation. Recent in vivo studies found a decrease of GSH in several areas of the brain from control, mild cognitive impairment, and AD subjects, which are correlated with cognitive decline. Critical Issues: Several strategies were developed to restore its intracellular level with the l-cysteine prodrugs or the oral administration of γ-glutamylcysteine to prevent alterations observed in AD. To date, no benefit on GSH level or on oxidative biomarkers has been reported in clinical trials. Thus, it remains uncertain if GSH could be considered a potential preventive or therapeutic approach or a biomarker for AD. Future Directions: We address how GSH-coupled nanocarriers represent a promising approach for the functionalization of nanocarriers to overcome the blood/brain barrier (BBB) for the brain delivery of GSH while avoiding cellular toxicity. It is also important to address the presence of GSH in exosomes for its potential intercellular transfer or its shuttle across the BBB under certain conditions. Antioxid. Redox Signal. 35, 270-292.
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Affiliation(s)
- Mohamed Haddad
- INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Canada.,Institute on Nutrition and Functional Foods, Université Laval, Québec, Canada
| | - Vincent Hervé
- INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Canada.,Institute on Nutrition and Functional Foods, Université Laval, Québec, Canada
| | - Mohamed Raâfet Ben Khedher
- INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Canada.,Institute on Nutrition and Functional Foods, Université Laval, Québec, Canada
| | | | - Charles Ramassamy
- INRS-Centre Armand-Frappier Santé Biotechnologie, Laval, Canada.,Institute on Nutrition and Functional Foods, Université Laval, Québec, Canada
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7
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Rose J, Brian C, Pappa A, Panayiotidis MI, Franco R. Mitochondrial Metabolism in Astrocytes Regulates Brain Bioenergetics, Neurotransmission and Redox Balance. Front Neurosci 2020; 14:536682. [PMID: 33224019 PMCID: PMC7674659 DOI: 10.3389/fnins.2020.536682] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 10/14/2020] [Indexed: 01/17/2023] Open
Abstract
In the brain, mitochondrial metabolism has been largely associated with energy production, and its dysfunction is linked to neuronal cell loss. However, the functional role of mitochondria in glial cells has been poorly studied. Recent reports have demonstrated unequivocally that astrocytes do not require mitochondria to meet their bioenergetics demands. Then, the question remaining is, what is the functional role of mitochondria in astrocytes? In this work, we review current evidence demonstrating that mitochondrial central carbon metabolism in astrocytes regulates overall brain bioenergetics, neurotransmitter homeostasis and redox balance. Emphasis is placed in detailing carbon source utilization (glucose and fatty acids), anaplerotic inputs and cataplerotic outputs, as well as carbon shuttles to neurons, which highlight the metabolic specialization of astrocytic mitochondria and its relevance to brain function.
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Affiliation(s)
- Jordan Rose
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, United States.,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Christian Brian
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, United States.,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Aglaia Pappa
- Department of Molecular Biology and Genetics, Democritus University of Thrace, Alexandroupolis, Greece
| | - Mihalis I Panayiotidis
- Department of Electron Microscopy & Molecular Pathology, Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
| | - Rodrigo Franco
- Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE, United States.,School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
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8
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The MT1G Gene in LUHMES Neurons Is a Sensitive Biomarker of Neurotoxicity. Neurotox Res 2020; 38:967-978. [PMID: 32870474 DOI: 10.1007/s12640-020-00272-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/19/2020] [Accepted: 08/10/2020] [Indexed: 10/23/2022]
Abstract
Identification of toxicants that underlie neurological diseases is a neglected area awaiting a valid strategy to identify such toxicants. We sought biomarkers that respond to known neurotoxicants in LUHMES immortalized neurons and evaluated these biomarkers for use in screening libraries of environmental toxicants. LUHMES immortalized human dopaminergic neurons were surveyed by RNA sequencing following challenge with parkinsonian toxicants rotenone, 6-hydroxydopamine, MPP+, and ziram (zinc dimethyldithiocarbamate; Zn2+DDC2), as well as additional toxicants paraquat, MS275, and methylmercury. The metallothionein gene MT1G was the most dynamic gene expression response to all seven toxicants. Multiple toxicants also increased transcripts for SLC30A1 and SLC30A2 zinc secretion transporters, the SLC7A11 xCT cystine/glutamate antiporter important for glutathione synthesis, DNA damage inducible transcript 3 (DDIT3), and secreted growth factors FIBIN and CXCL12, whereas several toxicants decreased expression of the apelin growth factor (APLN). These biomarker genes revealed stress responses to many toxicants at sub-cytotoxic concentrations. Since several of these biomarker genes and prior neurological disease studies implicated disruption of metal distribution, we tested metal chelator thiram (dimethyldithiocarbamate, DDC), ziram, and several other metals and metal chelates for cytotoxicity and induction of MT1G expression. Metals and chelators that caused dynamic increases in MT1G expression also caused cytotoxicity, except Ni2+DDC2 induced MT1G at 5 μM, but lacked cytotoxicity up to 100 μM. These results bolster prior work suggesting that neurons are characteristically sensitive to depletion of glutathione or to disruption of cellular metal distribution and provide biomarkers to search for such neurotoxicants in chemical libraries.
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Xie J, Gonzalez-Carter D, Tockary TA, Nakamura N, Xue Y, Nakakido M, Akiba H, Dirisala A, Liu X, Toh K, Yang T, Wang Z, Fukushima S, Li J, Quader S, Tsumoto K, Yokota T, Anraku Y, Kataoka K. Dual-Sensitive Nanomicelles Enhancing Systemic Delivery of Therapeutically Active Antibodies Specifically into the Brain. ACS NANO 2020; 14:6729-6742. [PMID: 32431145 DOI: 10.1021/acsnano.9b09991] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Delivering therapeutic antibodies into the brain across the blood-brain barrier at a therapeutic level is a promising while challenging approach in the treatment of neurological disorders. Here, we present a polymeric nanomicelle (PM) system capable of delivering therapeutically effective levels of 3D6 antibody fragments (3D6-Fab) into the brain parenchyma for inhibiting Aβ aggregation. PM assembly was achieved by charge-converting 3D6-Fab through pH-sensitive citraconylation to allow complexation with reductive-sensitive cationic polymers. Brain targeting was achieved by functionalizing the PM surface with glucose molecules to allow interaction with recycling glucose transporter (Glut)-1 proteins. Consequently, 41-fold enhanced 3D6-Fab accumulation in the brain was achieved by using the PM system compared to free 3D6-Fab. Furthermore, therapeutic benefits were obtained by successfully inhibiting Aβ1-42 aggregation in Alzheimer's disease mice systemically treated with 3D6-Fab-loaded glucosylated PM. Hence, this nanocarrier system represents a promising method for effectively delivering functional antibody agents into the brain and treating neurological diseases.
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Affiliation(s)
- Jinbing Xie
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
- Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
| | - Daniel Gonzalez-Carter
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Theofilus A Tockary
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Noriko Nakamura
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yonger Xue
- Department of Pharmacy, Shanghai Jiaotong University, 800 Dongchun Road, Shanghai 200240, China
| | - Makoto Nakakido
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Hiroki Akiba
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Anjaneyulu Dirisala
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Xueying Liu
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Kazuko Toh
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Tao Yang
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Zengtao Wang
- Department of Pharmacy, Shanghai Jiaotong University, 800 Dongchun Road, Shanghai 200240, China
| | - Shigeto Fukushima
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Junjie Li
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Sabina Quader
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Kouhei Tsumoto
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Takanori Yokota
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Yasutaka Anraku
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kazunori Kataoka
- Innovation Center of NanoMedicine, Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
- Institute for Future Initiatives, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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10
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Min HS, Kim HJ, Naito M, Ogura S, Toh K, Hayashi K, Kim BS, Fukushima S, Anraku Y, Miyata K, Kataoka K. Systemic Brain Delivery of Antisense Oligonucleotides across the Blood-Brain Barrier with a Glucose-Coated Polymeric Nanocarrier. Angew Chem Int Ed Engl 2020; 59:8173-8180. [PMID: 31995252 PMCID: PMC7317551 DOI: 10.1002/anie.201914751] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/13/2020] [Indexed: 12/14/2022]
Abstract
Current antisense oligonucleotide (ASO) therapies for the treatment of central nervous system (CNS) disorders are performed through invasive administration, thereby placing a major burden on patients. To alleviate this burden, we herein report systemic ASO delivery to the brain by crossing the blood-brain barrier using glycemic control as an external trigger. Glucose-coated polymeric nanocarriers, which can be bound by glucose transporter-1 expressed on the brain capillary endothelial cells, are designed for stable encapsulation of ASOs, with a particle size of about 45 nm and an adequate glucose-ligand density. The optimized nanocarrier efficiently accumulates in the brain tissue 1 h after intravenous administration and exhibits significant knockdown of a target long non-coding RNA in various brain regions, including the cerebral cortex and hippocampus. These results demonstrate that the glucose-modified polymeric nanocarriers enable noninvasive ASO administration to the brain for the treatment of CNS disorders.
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Affiliation(s)
- Hyun Su Min
- Department of Materials EngineeringGraduate School of EngineeringThe University of Tokyo7-3-1 Hongo, Bunkyo-kuTokyo113-8656Japan
| | - Hyun Jin Kim
- Center for Disease Biology and Integrative MedicineGraduate School of MedicineThe University of Tokyo7-3-1 Hongo, Bunkyo-kuTokyo113-0033Japan
| | - Mitsuru Naito
- Center for Disease Biology and Integrative MedicineGraduate School of MedicineThe University of Tokyo7-3-1 Hongo, Bunkyo-kuTokyo113-0033Japan
| | - Satomi Ogura
- Department of Materials EngineeringGraduate School of EngineeringThe University of Tokyo7-3-1 Hongo, Bunkyo-kuTokyo113-8656Japan
| | - Kazuko Toh
- Innovation Center of Nanomedicine (iCONM)Kawasaki Institute of Industrial Promotion3-25-14 Tonomachi, Kawasaki-kuKawasaki210-0821Japan
| | - Kotaro Hayashi
- Innovation Center of Nanomedicine (iCONM)Kawasaki Institute of Industrial Promotion3-25-14 Tonomachi, Kawasaki-kuKawasaki210-0821Japan
| | - Beob Soo Kim
- Department of Materials EngineeringGraduate School of EngineeringThe University of Tokyo7-3-1 Hongo, Bunkyo-kuTokyo113-8656Japan
| | - Shigeto Fukushima
- Innovation Center of Nanomedicine (iCONM)Kawasaki Institute of Industrial Promotion3-25-14 Tonomachi, Kawasaki-kuKawasaki210-0821Japan
| | - Yasutaka Anraku
- Innovation Center of Nanomedicine (iCONM)Kawasaki Institute of Industrial Promotion3-25-14 Tonomachi, Kawasaki-kuKawasaki210-0821Japan
- Department of BioengineeringGraduate School of EngineeringThe University of Tokyo7-3-1 Hongo, Bunkyo-kuTokyo113-8656Japan
| | - Kanjiro Miyata
- Department of Materials EngineeringGraduate School of EngineeringThe University of Tokyo7-3-1 Hongo, Bunkyo-kuTokyo113-8656Japan
| | - Kazunori Kataoka
- Innovation Center of Nanomedicine (iCONM)Kawasaki Institute of Industrial Promotion3-25-14 Tonomachi, Kawasaki-kuKawasaki210-0821Japan
- Institute for Future InitiativesThe University of Tokyo7-3-1 Hongo, Bunkyo-kuTokyo113-0033Japan
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11
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Dwivedi D, Megha K, Mishra R, Mandal PK. Glutathione in Brain: Overview of Its Conformations, Functions, Biochemical Characteristics, Quantitation and Potential Therapeutic Role in Brain Disorders. Neurochem Res 2020; 45:1461-1480. [PMID: 32297027 DOI: 10.1007/s11064-020-03030-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 04/04/2020] [Accepted: 04/07/2020] [Indexed: 12/28/2022]
Abstract
Glutathione (GSH) is an important antioxidant found abundantly and synthesized intracellularly in the cytosol in a tightly regulated fashion. It has diverse physiological functions, including protection against reactive oxygen species and nitrogen species, antioxidant defense as well as maintenance of cellular thiol status. The human brain due to the high oxygen consumption is extremely susceptible to the generation of reactive oxygen species. GSH plays a paramount role in brain antioxidant defense, maintaining redox homeostasis. The depletion of brain GSH has also been observed from both autopsies as well as in vivo MRS studies with aging and varied neurological disorders (Alzheimer's disease, Parkinson's disease, etc.). Therefore, GSH enrichment using supplementation is a promising avenue in the therapeutic development for these neurological disorders. This review will enrich the information on the importance of GSH synthesis, metabolism, functions, compartmentation and inter-organ transport, structural conformations and its quantitation via different techniques. The transportation of GSH in the brain via different interventional routes and its potential role in the development of therapeutic strategies for various brain disorders is also addressed. Very recent study found significant improvement of behavioral deficits including cognitive decline, depressive-like behaviors, in APP (NL-G-F/NL-G-FG-) mice due to oral GSH administration. This animal model study put an emergent need to complete GSH supplementation trial in MCI and AD patients for cognitive improvement as proposed earlier.
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Affiliation(s)
- Divya Dwivedi
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Kanu Megha
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Ritwick Mishra
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Pravat K Mandal
- Neuroimaging and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Manesar, Gurgaon, Haryana, India. .,Florey Institute of Neuroscience and Mental Health, Melbourne School of Medicine Campus, Parkville, Melbourne, Australia.
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12
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Bayır H, Anthonymuthu TS, Tyurina YY, Patel SJ, Amoscato AA, Lamade AM, Yang Q, Vladimirov GK, Philpott CC, Kagan VE. Achieving Life through Death: Redox Biology of Lipid Peroxidation in Ferroptosis. Cell Chem Biol 2020; 27:387-408. [PMID: 32275865 DOI: 10.1016/j.chembiol.2020.03.014] [Citation(s) in RCA: 127] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 03/02/2020] [Accepted: 03/17/2020] [Indexed: 12/11/2022]
Abstract
Redox balance is essential for normal brain, hence dis-coordinated oxidative reactions leading to neuronal death, including programs of regulated death, are commonly viewed as an inevitable pathogenic penalty for acute neuro-injury and neurodegenerative diseases. Ferroptosis is one of these programs triggered by dyshomeostasis of three metabolic pillars: iron, thiols, and polyunsaturated phospholipids. This review focuses on: (1) lipid peroxidation (LPO) as the major instrument of cell demise, (2) iron as its catalytic mechanism, and (3) thiols as regulators of pro-ferroptotic signals, hydroperoxy lipids. Given the central role of LPO, we discuss the engagement of selective and specific enzymatic pathways versus random free radical chemical reactions in the context of the phospholipid substrates, their biosynthesis, intracellular location, and related oxygenating machinery as participants in ferroptotic cascades. These concepts are discussed in the light of emerging neuro-therapeutic approaches controlling intracellular production of pro-ferroptotic phospholipid signals and their non-cell-autonomous spreading, leading to ferroptosis-associated necroinflammation.
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Affiliation(s)
- Hülya Bayır
- Children's Neuroscience Institute, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA; Center for Free Radical and Antioxidant Health, Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Safar Center for Resuscitation Research, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15224, USA.
| | - Tamil S Anthonymuthu
- Children's Neuroscience Institute, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA; Center for Free Radical and Antioxidant Health, Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Safar Center for Resuscitation Research, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Yulia Y Tyurina
- Center for Free Radical and Antioxidant Health, Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Sarju J Patel
- Genetics and Metabolism Section, Liver Diseases Branch, NIDDK, NIH, Bethesda, MD 20892, USA
| | - Andrew A Amoscato
- Center for Free Radical and Antioxidant Health, Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Andrew M Lamade
- Children's Neuroscience Institute, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA; Center for Free Radical and Antioxidant Health, Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Safar Center for Resuscitation Research, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Qin Yang
- Children's Neuroscience Institute, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA; Center for Free Radical and Antioxidant Health, Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Safar Center for Resuscitation Research, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Georgy K Vladimirov
- Center for Free Radical and Antioxidant Health, Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Caroline C Philpott
- Genetics and Metabolism Section, Liver Diseases Branch, NIDDK, NIH, Bethesda, MD 20892, USA
| | - Valerian E Kagan
- Children's Neuroscience Institute, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA; Center for Free Radical and Antioxidant Health, Department of Environmental Health, University of Pittsburgh, Pittsburgh, PA 15213, USA; Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia.
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13
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Belov Kirdajova D, Kriska J, Tureckova J, Anderova M. Ischemia-Triggered Glutamate Excitotoxicity From the Perspective of Glial Cells. Front Cell Neurosci 2020; 14:51. [PMID: 32265656 PMCID: PMC7098326 DOI: 10.3389/fncel.2020.00051] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/21/2020] [Indexed: 12/21/2022] Open
Abstract
A plethora of neurological disorders shares a final common deadly pathway known as excitotoxicity. Among these disorders, ischemic injury is a prominent cause of death and disability worldwide. Brain ischemia stems from cardiac arrest or stroke, both responsible for insufficient blood supply to the brain parenchyma. Glucose and oxygen deficiency disrupts oxidative phosphorylation, which results in energy depletion and ionic imbalance, followed by cell membrane depolarization, calcium (Ca2+) overload, and extracellular accumulation of excitatory amino acid glutamate. If tight physiological regulation fails to clear the surplus of this neurotransmitter, subsequent prolonged activation of glutamate receptors forms a vicious circle between elevated concentrations of intracellular Ca2+ ions and aberrant glutamate release, aggravating the effect of this ischemic pathway. The activation of downstream Ca2+-dependent enzymes has a catastrophic impact on nervous tissue leading to cell death, accompanied by the formation of free radicals, edema, and inflammation. After decades of “neuron-centric” approaches, recent research has also finally shed some light on the role of glial cells in neurological diseases. It is becoming more and more evident that neurons and glia depend on each other. Neuronal cells, astrocytes, microglia, NG2 glia, and oligodendrocytes all have their roles in what is known as glutamate excitotoxicity. However, who is the main contributor to the ischemic pathway, and who is the unsuspecting victim? In this review article, we summarize the so-far-revealed roles of cells in the central nervous system, with particular attention to glial cells in ischemia-induced glutamate excitotoxicity, its origins, and consequences.
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Affiliation(s)
- Denisa Belov Kirdajova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Kriska
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jana Tureckova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Miroslava Anderova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
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14
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Min HS, Kim HJ, Naito M, Ogura S, Toh K, Hayashi K, Kim BS, Fukushima S, Anraku Y, Miyata K, Kataoka K. Systemic Brain Delivery of Antisense Oligonucleotides across the Blood–Brain Barrier with a Glucose‐Coated Polymeric Nanocarrier. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914751] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Hyun Su Min
- Department of Materials Engineering Graduate School of Engineering The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Hyun Jin Kim
- Center for Disease Biology and Integrative Medicine Graduate School of Medicine The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
| | - Mitsuru Naito
- Center for Disease Biology and Integrative Medicine Graduate School of Medicine The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
| | - Satomi Ogura
- Department of Materials Engineering Graduate School of Engineering The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Kazuko Toh
- Innovation Center of Nanomedicine (iCONM) Kawasaki Institute of Industrial Promotion 3-25-14 Tonomachi, Kawasaki-ku Kawasaki 210-0821 Japan
| | - Kotaro Hayashi
- Innovation Center of Nanomedicine (iCONM) Kawasaki Institute of Industrial Promotion 3-25-14 Tonomachi, Kawasaki-ku Kawasaki 210-0821 Japan
| | - Beob Soo Kim
- Department of Materials Engineering Graduate School of Engineering The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Shigeto Fukushima
- Innovation Center of Nanomedicine (iCONM) Kawasaki Institute of Industrial Promotion 3-25-14 Tonomachi, Kawasaki-ku Kawasaki 210-0821 Japan
| | - Yasutaka Anraku
- Innovation Center of Nanomedicine (iCONM) Kawasaki Institute of Industrial Promotion 3-25-14 Tonomachi, Kawasaki-ku Kawasaki 210-0821 Japan
- Department of Bioengineering Graduate School of Engineering The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Kanjiro Miyata
- Department of Materials Engineering Graduate School of Engineering The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Kazunori Kataoka
- Innovation Center of Nanomedicine (iCONM) Kawasaki Institute of Industrial Promotion 3-25-14 Tonomachi, Kawasaki-ku Kawasaki 210-0821 Japan
- Institute for Future Initiatives The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033 Japan
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15
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Zong H, Peng J, Li XR, Liu M, Hu Y, Li J, Zang Y, Li X, James TD. A fluorogenic probe for tracking GSH flux in developing neurons. Chem Commun (Camb) 2020; 56:515-518. [PMID: 31825409 DOI: 10.1039/c9cc07753g] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Understanding GSH flux in developing neurons is prerequisite to reveal its role in neuronal development but necessiates an ultrasensitive assay. By systematically exploring key structural factors determing probe sensitivity in live cells, we developed a fluorogenic probe capable of imaging subtle GSH fluctuations in developing neurons.
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Affiliation(s)
- Haichao Zong
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
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16
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Upregulation of Peroxiredoxin 3 Protects Afg3l2-KO Cortical Neurons In Vitro from Oxidative Stress: A Paradigm for Neuronal Cell Survival under Neurodegenerative Conditions. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4721950. [PMID: 31781336 PMCID: PMC6875171 DOI: 10.1155/2019/4721950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/03/2019] [Accepted: 09/14/2019] [Indexed: 02/03/2023]
Abstract
Several neurodegenerative disorders exhibit selective vulnerability, with subsets of
neurons more affected than others, possibly because of the high expression of an altered
gene or the presence of particular features that make them more susceptible to insults. On
the other hand, resilient neurons may display the ability to develop antioxidant defenses,
particularly in diseases of mitochondrial origin, where oxidative stress might contribute
to the neurodegenerative process. In this work, we investigated the oxidative stress
response of embryonic fibroblasts and cortical neurons obtained from
Afg3l2-KO mice. AFG3L2 encodes a subunit of a protease
complex that is expressed in mitochondria and acts as both quality control and regulatory
enzyme affecting respiration and mitochondrial dynamics. When cells were subjected to an
acute oxidative stress protocol, the survival of AFG3L2-KO MEFs was not significantly
influenced and was comparable to that of WT; however, the basal level of the antioxidant
molecule glutathione was higher. Indeed, glutathione depletion strongly affected the
viability of KO, but not of WT MEF, thereby indicating that oxidative stress is more
elevated in KO MEF even though well controlled by glutathione. On the other hand, when
cortical KO neurons were put in culture, they immediately appeared more vulnerable than WT
to the acute oxidative stress condition, but after few days in vitro, the situation was
reversed with KO neurons being more resistant than WT to acute stress. This compensatory,
protective competence was not due to the upregulation of glutathione, rather of two
mitochondrial antioxidant proteins: superoxide dismutase 2 and, at an even higher level,
peroxiredoxin 3. This body of evidence sheds light on the capability of neurons to
activate neuroprotective pathways and points the attention to peroxiredoxin 3, an
antioxidant enzyme that might be critical for neuronal survival also in other disorders
affecting mitochondria.
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17
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Abstract
Glucose is the long-established, obligatory fuel for brain that fulfills many critical functions, including ATP production, oxidative stress management, and synthesis of neurotransmitters, neuromodulators, and structural components. Neuronal glucose oxidation exceeds that in astrocytes, but both rates increase in direct proportion to excitatory neurotransmission; signaling and metabolism are closely coupled at the local level. Exact details of neuron-astrocyte glutamate-glutamine cycling remain to be established, and the specific roles of glucose and lactate in the cellular energetics of these processes are debated. Glycolysis is preferentially upregulated during brain activation even though oxygen availability is sufficient (aerobic glycolysis). Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in excess of oxygen, and adrenergic regulation of aerobic glycolysis draws attention to astrocytic metabolism, particularly glycogen turnover, which has a high impact on the oxygen-carbohydrate mismatch. Aerobic glycolysis is proposed to be predominant in young children and specific brain regions, but re-evaluation of data is necessary. Shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation, neurotransmission, and memory consolidation are controversial topics for which alternative mechanisms are proposed. Nutritional therapy and vagus nerve stimulation are translational bridges from metabolism to clinical treatment of diverse brain disorders.
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Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences , Little Rock, Arkansas ; and Department of Cell Biology and Physiology, University of New Mexico , Albuquerque, New Mexico
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18
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Interleukin-1β Protects Neurons against Oxidant-Induced Injury via the Promotion of Astrocyte Glutathione Production. Antioxidants (Basel) 2018; 7:antiox7080100. [PMID: 30044427 PMCID: PMC6115796 DOI: 10.3390/antiox7080100] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/04/2018] [Accepted: 07/21/2018] [Indexed: 01/13/2023] Open
Abstract
Interleukin-1β (IL-1β), a key cytokine that drives neuroinflammation in the Central Nervous System (CNS), is enhanced in many neurological diseases/disorders. Although IL-1β contributes to and/or sustains pathophysiological processes in the CNS, we recently demonstrated that IL-1β can protect cortical astrocytes from oxidant injury in a glutathione (GSH)-dependent manner. To test whether IL-1β could similarly protect neurons against oxidant stress, near pure neuronal cultures or mixed cortical cell cultures containing neurons and astrocytes were exposed to the organic peroxide, tert-butyl hydroperoxide (t-BOOH), following treatment with IL-1β or its vehicle. Neurons and astrocytes in mixed cultures, but not pure neurons, were significantly protected from the toxicity of t-BOOH following treatment with IL-1β in association with enhanced GSH production/release. IL-1β failed to increase the GSH levels or to provide protection against t-BOOH toxicity in chimeric mixed cultures consisting of IL-1R1+/+ neurons plated on top of IL-1R1−/− astrocytes. The attenuation of GSH release via block of multidrug resistance-associated protein 1 (MRP1) transport also abrogated the protective effect of IL-1β. These protective effects were not strictly an in vitro phenomenon as we found an increased striatal vulnerability to 3-nitropropionic acid-mediated oxidative stress in IL-1R1 null mice. Overall, our data indicate that IL-1β protects neurons against oxidant injury and that this likely occurs in a non-cell-autonomous manner that relies on an increase in astrocyte GSH production and release.
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19
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Abstract
SIGNIFICANCE Numerous studies have demonstrated the actions of reactive oxygen species (ROS) as regulators of several physiological processes. In this study, we discuss how redox signaling mechanisms operate to control different processes such as neuronal differentiation, oligodendrocyte differentiation, dendritic growth, and axonal growth. Recent Advances: Redox homeostasis regulates the physiology of neural stem cells (NSCs). Notably, the neuronal differentiation process of NSCs is determined by a change toward oxidative metabolism, increased levels of mitochondrial ROS, increased activity of NADPH oxidase (NOX) enzymes, decreased levels of Nrf2, and differential regulation of different redoxins. Furthermore, during the neuronal maturation processes, NOX and MICAL produce ROS to regulate cytoskeletal dynamics, which control the dendritic and axonal growth, as well as the axonal guidance. CRITICAL ISSUES The redox homeostasis changes are, in part, attributed to cell metabolism and compartmentalized production of ROS, which is regulated, sensed, and transduced by different molecules such as thioredoxins, glutaredoxins, peroxiredoxins, and nucleoredoxin to control different signaling pathways in different subcellular regions. The study of how these elements cooperatively act is essential for the understanding of nervous system development, as well as the application of regenerative therapies that recapitulate these processes. FUTURE DIRECTIONS The information about these topics in the last two decades leads us to the conclusion that the role of ROS signaling in development of the nervous system is more important than it was previously believed and makes clear the importance of exploring in more detail the mechanisms of redox signaling. Antioxid. Redox Signal. 28, 1603-1625.
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Affiliation(s)
- Mauricio Olguín-Albuerne
- División de Neurociencias, Instituto de Fisiología Celular , Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Julio Morán
- División de Neurociencias, Instituto de Fisiología Celular , Universidad Nacional Autónoma de México, Ciudad de México, México
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20
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Patel D, Rathinam M, Jarvis C, Mahimainathan L, Henderson G, Narasimhan M. Role for Cystathionine γ Lyase (CSE) in an Ethanol (E)-Induced Lesion in Fetal Brain GSH Homeostasis. Int J Mol Sci 2018; 19:ijms19051537. [PMID: 29786653 PMCID: PMC5983808 DOI: 10.3390/ijms19051537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/19/2018] [Accepted: 05/19/2018] [Indexed: 02/06/2023] Open
Abstract
Earlier, we reported that gestational ethanol (E) can dysregulate neuron glutathione (GSH) homeostasis partially via impairing the EAAC1-mediated inward transport of Cysteine (Cys) and this can affect fetal brain development. In this study, we investigated if there is a role for the transulfuration pathway (TSP), a critical bio-synthetic point to supply Cys in E-induced dysregulation of GSH homeostasis. These studies utilized an in utero E binge model where the pregnant Sprague⁻Dawley (SD) rat dams received five doses of E at 3.5 g/kg by gastric intubation beginning embryonic day (ED) 17 until ED19 separated by 12 h. The postnatal day 7 (PN7) alcohol model employed an oral dosing of 4 g/kg body weight split into 2 feedings at 2 h interval and an iso-caloric and iso-volumic equivalent maltose-dextrin milk solution served as controls. The in vitro model consisted of cerebral cortical neuron cultures from embryonic day (ED) 16⁻17 fetus from SD rats and differentiated neurons from ED18 rat cerebral cortical neuroblasts. E concentrations were 4 mg/mL. E induced an accumulation of cystathionine in primary cortical neurons (PCNs), 2nd trimester equivalent in utero binge, and 3rd trimester equivalent PN7 model suggesting that breakdown of cystathionine, a required process for Cys supply is impaired. This was associated with a significant reduction in cystathionine γ-lyase (CSE) protein expression in PCN (p < 0.05) and in fetal cerebral cortex in utero (53%, p < 0.05) without a change in the expression of cystathionine β-synthase (CBS). Concomitantly, E decreased Cse mRNA expression in PCNs (by 32% within 6 h of exposure, p < 0.05) and in fetal brain (33%, p < 0.05). In parallel, knock down of CSE in differentiated rat cortical neuroblasts exaggerated the E-induced ROS, GSH loss with a pronounced caspase-3 activation and cell death. These studies illustrate the importance of TSP in CSE-related maintenance of GSH and the downstream events via Cys synthesis in neurons and fetal brain.
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Affiliation(s)
- Dhyanesh Patel
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, USA.
| | - Marylatha Rathinam
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, USA.
| | - Courtney Jarvis
- Department of Microbiology and Immunology, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, USA.
| | - Lenin Mahimainathan
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, USA.
| | - George Henderson
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, USA.
| | - Madhusudhanan Narasimhan
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, USA.
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21
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Bylicky MA, Mueller GP, Day RM. Mechanisms of Endogenous Neuroprotective Effects of Astrocytes in Brain Injury. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:6501031. [PMID: 29805731 PMCID: PMC5901819 DOI: 10.1155/2018/6501031] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 02/19/2018] [Indexed: 12/11/2022]
Abstract
Astrocytes, once believed to serve only as "glue" for the structural support of neurons, have been demonstrated to serve critical functions for the maintenance and protection of neurons, especially under conditions of acute or chronic injury. There are at least seven distinct mechanisms by which astrocytes protect neurons from damage; these are (1) protection against glutamate toxicity, (2) protection against redox stress, (3) mediation of mitochondrial repair mechanisms, (4) protection against glucose-induced metabolic stress, (5) protection against iron toxicity, (6) modulation of the immune response in the brain, and (7) maintenance of tissue homeostasis in the presence of DNA damage. Astrocytes support these critical functions through specialized responses to stress or toxic conditions. The detoxifying activities of astrocytes are essential for maintenance of the microenvironment surrounding neurons and in whole tissue homeostasis. Improved understanding of the mechanisms by which astrocytes protect the brain could lead to the development of novel targets for the development of neuroprotective strategies.
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Affiliation(s)
- Michelle A. Bylicky
- Department of Anatomy, Physiology, and Genetics, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Gregory P. Mueller
- Department of Anatomy, Physiology, and Genetics, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Regina M. Day
- Department of Pharmacology and Molecular Therapeutics, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
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22
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Howarth C, Sutherland B, Choi HB, Martin C, Lind BL, Khennouf L, LeDue JM, Pakan JMP, Ko RWY, Ellis-Davies G, Lauritzen M, Sibson NR, Buchan AM, MacVicar BA. A Critical Role for Astrocytes in Hypercapnic Vasodilation in Brain. J Neurosci 2017; 37:2403-2414. [PMID: 28137973 PMCID: PMC5354350 DOI: 10.1523/jneurosci.0005-16.2016] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 11/21/2016] [Accepted: 12/14/2016] [Indexed: 11/21/2022] Open
Abstract
Cerebral blood flow (CBF) is controlled by arterial blood pressure, arterial CO2, arterial O2, and brain activity and is largely constant in the awake state. Although small changes in arterial CO2 are particularly potent to change CBF (1 mmHg variation in arterial CO2 changes CBF by 3%-4%), the coupling mechanism is incompletely understood. We tested the hypothesis that astrocytic prostaglandin E2 (PgE2) plays a key role for cerebrovascular CO2 reactivity, and that preserved synthesis of glutathione is essential for the full development of this response. We combined two-photon imaging microscopy in brain slices with in vivo work in rats and C57BL/6J mice to examine the hemodynamic responses to CO2 and somatosensory stimulation before and after inhibition of astrocytic glutathione and PgE2 synthesis. We demonstrate that hypercapnia (increased CO2) evokes an increase in astrocyte [Ca2+]i and stimulates COX-1 activity. The enzyme downstream of COX-1 that synthesizes PgE2 (microsomal prostaglandin E synthase-1) depends critically for its vasodilator activity on the level of glutathione in the brain. We show that, when glutathione levels are reduced, astrocyte calcium-evoked release of PgE2 is decreased and vasodilation triggered by increased astrocyte [Ca2+]iin vitro and by hypercapnia in vivo is inhibited. Astrocyte synthetic pathways, dependent on glutathione, are involved in cerebrovascular reactivity to CO2 Reductions in glutathione levels in aging, stroke, or schizophrenia could lead to dysfunctional regulation of CBF and subsequent neuronal damage.SIGNIFICANCE STATEMENT Neuronal activity leads to the generation of CO2, which has previously been shown to evoke cerebral blood flow (CBF) increases via the release of the vasodilator PgE2 We demonstrate that hypercapnia (increased CO2) evokes increases in astrocyte calcium signaling, which in turn stimulates COX-1 activity and generates downstream PgE2 production. We demonstrate that astrocyte calcium-evoked production of the vasodilator PgE2 is critically dependent on brain levels of the antioxidant glutathione. These data suggest a novel role for astrocytes in the regulation of CO2-evoked CBF responses. Furthermore, these results suggest that depleted glutathione levels, which occur in aging and stroke, will give rise to dysfunctional CBF regulation and may result in subsequent neuronal damage.
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Affiliation(s)
- Clare Howarth
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, United Kingdom
- Department of Psychology, University of Sheffield, Sheffield, S10 2TP, United Kingdom
| | - Brad Sutherland
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, United Kingdom
| | - Hyun B Choi
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Chris Martin
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, United Kingdom
- Department of Psychology, University of Sheffield, Sheffield, S10 2TP, United Kingdom
| | - Barbara Lykke Lind
- Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Lila Khennouf
- Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Jeffrey M LeDue
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Janelle M P Pakan
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Rebecca W Y Ko
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Graham Ellis-Davies
- Department of Neuroscience, Mount Sinai School of Medicine, New York, New York 10028, and
| | - Martin Lauritzen
- Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen, DK-2200 Copenhagen N, Denmark
- Department of Clinical Neurophysiology, Rigshospitalet, DK-2600 Glostrup, Denmark
| | - Nicola R Sibson
- Cancer Research United Kingdom and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, United Kingdom
| | - Alastair M Buchan
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, United Kingdom,
| | - Brian A MacVicar
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada,
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Glutathione in the human brain: Review of its roles and measurement by magnetic resonance spectroscopy. Anal Biochem 2016; 529:127-143. [PMID: 28034792 DOI: 10.1016/j.ab.2016.12.022] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 12/21/2016] [Accepted: 12/23/2016] [Indexed: 12/12/2022]
Abstract
We review the transport, synthesis and catabolism of glutathione in the brain as well as its compartmentation and biochemistry in different brain cells. The major reactions involving glutathione are reviewed and the factors limiting its availability in brain cells are discussed. We also describe and critique current methods for measuring glutathione in the human brain using magnetic resonance spectroscopy, and review the literature on glutathione measurements in healthy brains and in neurological, psychiatric, neurodegenerative and neurodevelopmental conditions In summary: Healthy human brain glutathione concentration is ∼1-2 mM, but it varies by brain region, with evidence of gender differences and age effects; in neurological disease glutathione appears reduced in multiple sclerosis, motor neurone disease and epilepsy, while being increased in meningiomas; in psychiatric disease the picture is complex and confounded by methodological differences, regional effects, length of disease and drug-treatment. Both increases and decreases in glutathione have been reported in depression and schizophrenia. In Alzheimer's disease and mild cognitive impairment there is evidence for a decrease in glutathione compared to age-matched healthy controls. Improved methods to measure glutathione in vivo will provide better precision in glutathione determination and help resolve the complex biochemistry of this molecule in health and disease.
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Hijacking microglial glutathione by inorganic arsenic impels bystander death of immature neurons through extracellular cystine/glutamate imbalance. Sci Rep 2016; 6:30601. [PMID: 27477106 PMCID: PMC4967897 DOI: 10.1038/srep30601] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/04/2016] [Indexed: 12/21/2022] Open
Abstract
Arsenic-induced altered microglial activity leads to neuronal death, but the causative mechanism remains unclear. The present study showed, arsenic-exposed (10 μM) microglial (N9) culture supernatant induced bystander death of neuro-2a (N2a), which was further validated with primary microglia and immature neuronal cultures. Results indicated that arsenic-induced GSH synthesis by N9 unfavorably modified the extracellular milieu for N2a by lowering cystine and increasing glutamate concentration. Similar result was observed in N9-N2a co-culture. Co-exposure of arsenic and 250 μM glutamate, less than the level (265 μM) detected in arsenic-exposed N9 culture supernatant, compromised N2a viability which was rescued by cystine supplementation. Therefore, microglia executes bystander N2a death by competitive inhibition of system Xc- (xCT) through extracellular cystine/glutamate imbalance. We confirmed the role of xCT in mediating bystander N2a death by siRNA inhibition studies. Ex-vivo primary microglia culture supernatant from gestationally exposed mice measured to contain lower cystine and higher glutamate compared to control and N-acetyl cysteine co-treated group. Immunofluorescence staining of brain cryosections from treated group showed more dead immature neurons with no such effect on microglia. Collectively, we showed, in presence of arsenic microglia alters cystine/glutamate balance through xCT in extracellular milieu leading to bystander death of immature neurons.
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Differences in vulnerability of neurons and astrocytes to heme oxygenase-1 modulation: Implications for mitochondrial ferritin. Sci Rep 2016; 6:24200. [PMID: 27097841 PMCID: PMC4838889 DOI: 10.1038/srep24200] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/22/2016] [Indexed: 11/08/2022] Open
Abstract
Induction of the antioxidant enzyme heme oxygenase-1 (HO-1) was observed in both astrocytes and neurons in the substantia nigra of patients with Parkinson's disease (PD). In the current study, we investigated whether HO-1 behaves differently between neurons and astrocytes under the condition of neurotoxicity related to PD. The results showed a time-dependent HO-1 upregulation in primary cultured ventral mesencephalon neurons and astrocytes treated with the mitochondria complex I inhibitor 1-methyl-4-phenylpyridinium (MPP(+)) or recombinant α-synuclein. However, HO-1 upregulation appeared much later in neurons than in astrocytes. The HO-1 inhibitor zinc protoporphyrin (ZnPP) aggravated MPP(+)- or α-synuclein-induced oxidative damage in both astrocytes and neurons, indicating that this HO-1 response was cytoprotective. For neurons, the HO-1 activator cobalt protoporphyrin IX (CoPPIX) exerted protective effects against MPP(+) or α-synuclein during moderate HO-1 upregulation, but it aggravated damage at the peak of the HO-1 response. For astrocytes, CoPPIXalways showed protective effects. Higher basal and CoPPIX-induced mitochondrial ferritin (MtFt) levels were detected in astrocytes. Lentivirus-mediated MtFt overexpression rescued the neuronal damage induced by CoPPIX, indicating that large MtFt buffering capacity contributes to pronounced HO-1 tolerance in astrocytes. Such findings suggest that astrocyte-targeted HO-1 interventions and MtFt modulations have potential as novel pharmacological strategies in PD.
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Central Role of Glutamate Metabolism in the Maintenance of Nitrogen Homeostasis in Normal and Hyperammonemic Brain. Biomolecules 2016; 6:biom6020016. [PMID: 27023624 PMCID: PMC4919911 DOI: 10.3390/biom6020016] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/10/2016] [Accepted: 03/15/2016] [Indexed: 12/21/2022] Open
Abstract
Glutamate is present in the brain at an average concentration—typically 10–12 mM—far in excess of those of other amino acids. In glutamate-containing vesicles in the brain, the concentration of glutamate may even exceed 100 mM. Yet because glutamate is a major excitatory neurotransmitter, the concentration of this amino acid in the cerebral extracellular fluid must be kept low—typically µM. The remarkable gradient of glutamate in the different cerebral compartments: vesicles > cytosol/mitochondria > extracellular fluid attests to the extraordinary effectiveness of glutamate transporters and the strict control of enzymes of glutamate catabolism and synthesis in well-defined cellular and subcellular compartments in the brain. A major route for glutamate and ammonia removal is via the glutamine synthetase (glutamate ammonia ligase) reaction. Glutamate is also removed by conversion to the inhibitory neurotransmitter γ-aminobutyrate (GABA) via the action of glutamate decarboxylase. On the other hand, cerebral glutamate levels are maintained by the action of glutaminase and by various α-ketoglutarate-linked aminotransferases (especially aspartate aminotransferase and the mitochondrial and cytosolic forms of the branched-chain aminotransferases). Although the glutamate dehydrogenase reaction is freely reversible, owing to rapid removal of ammonia as glutamine amide, the direction of the glutamate dehydrogenase reaction in the brain in vivo is mainly toward glutamate catabolism rather than toward the net synthesis of glutamate, even under hyperammonemia conditions. During hyperammonemia, there is a large increase in cerebral glutamine content, but only small changes in the levels of glutamate and α-ketoglutarate. Thus, the channeling of glutamate toward glutamine during hyperammonemia results in the net synthesis of 5-carbon units. This increase in 5-carbon units is accomplished in part by the ammonia-induced stimulation of the anaplerotic enzyme pyruvate carboxylase. Here, we suggest that glutamate may constitute a buffer or bulwark against changes in cerebral amine and ammonia nitrogen. Although the glutamate transporters are briefly discussed, the major emphasis of the present review is on the enzymology contributing to the maintenance of glutamate levels under normal and hyperammonemic conditions. Emphasis will also be placed on the central role of glutamate in the glutamine-glutamate and glutamine-GABA neurotransmitter cycles between neurons and astrocytes. Finally, we provide a brief and selective discussion of neuropathology associated with altered cerebral glutamate levels.
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Harris JL, Choi IY, Brooks WM. Probing astrocyte metabolism in vivo: proton magnetic resonance spectroscopy in the injured and aging brain. Front Aging Neurosci 2015; 7:202. [PMID: 26578948 PMCID: PMC4623195 DOI: 10.3389/fnagi.2015.00202] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 10/07/2015] [Indexed: 11/18/2022] Open
Abstract
Following a brain injury, the mobilization of reactive astrocytes is part of a complex neuroinflammatory response that may have both harmful and beneficial effects. There is also evidence that astrocytes progressively accumulate in the normal aging brain, increasing in both number and size. These astrocyte changes in normal brain aging may, in the event of an injury, contribute to the exacerbated injury response and poorer outcomes observed in older traumatic brain injury (TBI) survivors. Here we present our view that proton magnetic resonance spectroscopy (1H-MRS), a neuroimaging approach that probes brain metabolism within a defined region of interest, is a promising technique that may provide insight into astrocyte metabolic changes in the injured and aging brain in vivo. Although 1H-MRS does not specifically differentiate between cell types, it quantifies certain metabolites that are highly enriched in astrocytes (e.g., Myo-inositol, mlns), or that are involved in metabolic shuttling between astrocytes and neurons (e.g., glutamate and glutamine). Here we focus on metabolites detectable by 1H-MRS that may serve as markers of astrocyte metabolic status. We review the physiological roles of these metabolites, discuss recent 1H-MRS findings in the injured and aging brain, and describe how an astrocyte metabolite profile approach might be useful in clinical medicine and clinical trials.
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Affiliation(s)
- Janna L Harris
- Hoglund Brain Imaging Center, University of Kansas Medical Center Kansas City, KS, USA ; Department of Anatomy and Cell Biology, University of Kansas Medical Center Kansas City, KS, USA
| | - In-Young Choi
- Hoglund Brain Imaging Center, University of Kansas Medical Center Kansas City, KS, USA ; Department of Neurology, University of Kansas Medical Center Kansas City, KS, USA ; Department of Molecular and Integrative Physiology, University of Kansas Medical Center Kansas City, KS, USA
| | - William M Brooks
- Hoglund Brain Imaging Center, University of Kansas Medical Center Kansas City, KS, USA ; Department of Neurology, University of Kansas Medical Center Kansas City, KS, USA ; Department of Molecular and Integrative Physiology, University of Kansas Medical Center Kansas City, KS, USA
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Xu X, Song N, Wang R, Jiang H, Xie J. Preferential Heme Oxygenase-1 Activation in Striatal Astrocytes Antagonizes Dopaminergic Neuron Degeneration in MPTP-Intoxicated Mice. Mol Neurobiol 2015; 53:5056-65. [PMID: 26385576 DOI: 10.1007/s12035-015-9437-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 09/10/2015] [Indexed: 01/01/2023]
Abstract
Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) accompanied by increased oxidative damage. Astrocytes, which are the most abundant glial cell types in the brain, possess higher antioxidant potential partially due to preferentially activated nuclear factor E2-related factor 2 genes. Heme oxygenase isoform 1 (HO-1) is crucial for the response to oxidative stress via the catabolism of heme to carbon monoxide, bilirubin, and iron. In the present study, we aimed to investigate astroglial expression of HO-1 in the SNpc, especially in the striatum of a subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mouse model of PD, and to investigate the neuroprotective effects of intraventricularly administrated HO-1 activator cobalt protoporphyrin IX (CoPPIX). The results showed that HO-1 was faintly distributed in neurons but not astrocytes in the normal SNpc and striatum. MPTP triggered a robust HO-1 response in the astrocytes of the striatum after 1-day treatment, but the HO-1 levels declined dramatically at day 3 and were completely undetectable at day 5. Intraventricular administration of CoPPIX for 8 days could preferentially activate HO-1 in astrocytes in the striatum but not SNpc. The content of striatal dopamine and its derivatives was restored in the subacute MPTP models. CoPPIX also increased the number of dopaminergic neurons and the tyrosine hydroxylase levels in the SNpc. These results suggest that inadequate HO-1 in striatal astrocytes might contribute to the limited antioxidant defense and dopaminergic neuron degeneration in PD, and preferential HO-1 activation in striatal astrocytes might be neuroprotective. The study thus sheds light on the targeting of HO-1 in striatal astrocytes for PD therapeutics.
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Affiliation(s)
- Xiaofeng Xu
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, 266071, China.,Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao, 266071, China
| | - Ning Song
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, 266071, China.,Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao, 266071, China
| | - Ranran Wang
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, 266071, China.,Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao, 266071, China
| | - Hong Jiang
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, 266071, China.,Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao, 266071, China
| | - Junxia Xie
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, 266071, China. .,Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao, 266071, China.
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Majumder P, Duchen MR, Gale JE. Cellular glutathione content in the organ of Corti and its role during ototoxicity. Front Cell Neurosci 2015; 9:143. [PMID: 25972783 PMCID: PMC4412067 DOI: 10.3389/fncel.2015.00143] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/26/2015] [Indexed: 12/31/2022] Open
Abstract
Glutathione (GSH) is the major scavenger of reactive oxygen species (ROS) inside cells. We used live confocal imaging in order to clarify the role of GSH in the biology of the organ of Corti, the sensory epithelium of the cochlea, before, during and after the onset of hearing and in ~1 year old mice. GSH content was measured using monochlorobimane (MCB), a non-fluorescent cell permeant bimane that reacts with GSH, forming a fluorescent adduct through a reaction catalyzed by glutathione-S-transferase. GSH content increased significantly in inner hair cells during maturation in young adult animals, whereas there was no significant change in the outer hair cells. However, the GSH content in inner hair cells was significantly reduced in ~1 year old mice. The GSH content of supporting cells was comparatively stable over these ages. To test whether the GSH content played a significant protective role during ototoxicity, GSH synthesis was inhibited by buthionine sulfoximine (BSO) in organotypic cochlear explant cultures from immature mice. BSO treatment alone, which reduced GSH by 65 and 85% in inner hair cells and outer hair cells respectively, did not cause any significant cell death. Surprisingly, GSH depletion had no significant effect on hair cell survival even during exposure to the ototoxic aminoglycoside neomycin. These data suggest that the involvement of ROS during aminoglycoside-induced hair cell death is less clear than previously thought and requires further investigation.
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Affiliation(s)
| | - Michael R Duchen
- Department of Cell and Developmental Biology, University College London London, UK
| | - Jonathan E Gale
- UCL Ear Institute, University College London London, UK ; Department of Cell and Developmental Biology, University College London London, UK
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He Y, Jackman NA, Thorn TL, Vought VE, Hewett SJ. Interleukin-1β protects astrocytes against oxidant-induced injury via an NF-κB-dependent upregulation of glutathione synthesis. Glia 2015; 63:1568-80. [PMID: 25880604 DOI: 10.1002/glia.22828] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 03/12/2015] [Indexed: 01/17/2023]
Abstract
Astrocytes produce and export the antioxidant glutathione (GSH). Previously, we found that interleukin-1β (IL-1β) enhanced the expression of astrocyte system xc (-) , the transporter that delivers the rate-limiting substrate for GSH synthesis-cyst(e)ine. Herein, we demonstrate directly that IL-1β mediates a time-dependent increase in extracellular GSH levels in cortical astrocyte cultures, suggesting both enhanced synthesis and export. This increased GSH production was blocked by inhibition of nuclear factor-κB (NF-κB) activity but not by inhibition of p38 MAPK. To determine whether this increase could provide protection against oxidative stress, the oxidants tert-butyl hydroperoxide (tBOOH) and ferrous sulfate (FeSO4 ) were employed. IL-1β treatment prevented the increase in reactive oxygen species produced in astrocytes following tBOOH exposure. Additionally, the toxicity induced by tBOOH or FeSO4 exposure was significantly attenuated following treatment with IL-1β, an effect reversed by concomitant exposure to l-buthionine-S,R-sulfoximine (BSO), which prevented the IL-1β-mediated rise in GSH production. IL-1β failed to increase GSH or to provide protection against t-BOOH toxicity in astrocyte cultures derived from IL-1R1 null mutant mice. Overall, our data indicate that under certain conditions IL-1β may be an important stimulus for increasing astrocyte GSH production, and potentially, total antioxidant capacity in brain, via an NF-κB-dependent process.
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Affiliation(s)
- Yan He
- Department of Biology and Program in Neuroscience, Syracuse University, Syracuse, New York
| | - Nicole A Jackman
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut
| | - Trista L Thorn
- Department of Biology and Program in Neuroscience, Syracuse University, Syracuse, New York
| | - Valarie E Vought
- Department of Biology and Program in Neuroscience, Syracuse University, Syracuse, New York
| | - Sandra J Hewett
- Department of Biology and Program in Neuroscience, Syracuse University, Syracuse, New York
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Synaptic NMDA receptor activity is coupled to the transcriptional control of the glutathione system. Nat Commun 2015; 6:6761. [PMID: 25854456 PMCID: PMC4403319 DOI: 10.1038/ncomms7761] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/25/2015] [Indexed: 02/07/2023] Open
Abstract
How the brain’s antioxidant defenses adapt to changing demand is incompletely understood. Here we show that synaptic activity is coupled, via the NMDA receptor (NMDAR), to control of the glutathione antioxidant system. This tunes antioxidant capacity to reflect the elevated needs of an active neuron, guards against future increased demand and maintains redox balance in the brain. This control is mediated via a programme of gene expression changes that boosts the synthesis, recycling and utilization of glutathione, facilitating ROS detoxification and preventing Puma-dependent neuronal apoptosis. Of particular importance to the developing brain is the direct NMDAR-dependent transcriptional control of glutathione biosynthesis, disruption of which can lead to degeneration. Notably, these activity-dependent cell-autonomous mechanisms were found to cooperate with non-cell-autonomous Nrf2-driven support from astrocytes to maintain neuronal GSH levels in the face of oxidative insults. Thus, developmental NMDAR hypofunction and glutathione system deficits, separately implicated in several neurodevelopmental disorders, are mechanistically linked. How the brain’s antioxidant defenses adapt to changing demand is not well understood. Here the authors demonstrate that synaptic activity is coupled to transcriptional control of the glutathione antioxidant system via NMDA receptors, enabling neurons to tune their antioxidant defenses.
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Dai X, Zhang T, Li Y, Yan T, Wang PC, Miao JY, Zhao BX. An effective fluorescent probe to detect glutathione from other sulfhydryl compounds in aqueous solution and its living cell imaging. RSC Adv 2014. [DOI: 10.1039/c4ra09712b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Abstract
Neurons are more vulnerable to oxidative stress than astrocytes, the reasons for which have yet to be fully elucidated. Understanding the cellular and molecular mechanisms which contribute to this enhanced vulnerability is key to efforts aimed at ameliorating neuronal health and resilience to oxidative stress, particularly in the context of neurodegenerative disease, which is characterized by progressive dysfunction and loss of neurons specifically, and in which oxidative stress is considered a central aetiological contributor. Biological factors which may influence neuronal susceptibility to oxidative stress, in normal and neurodegenerative contexts, are reviewed in the present article, with a focus on properties intrinsic to the neuronal cell type and on properties related to neuronal reliance on surrounding astrocytes.
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Tomioka NH, Nakamura M, Doshi M, Deguchi Y, Ichida K, Morisaki T, Hosoyamada M. Ependymal cells of the mouse brain express urate transporter 1 (URAT1). Fluids Barriers CNS 2013; 10:31. [PMID: 24156345 PMCID: PMC4015888 DOI: 10.1186/2045-8118-10-31] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 10/22/2013] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Elevated uric acid (UA) is commonly associated with gout and it is also a known cardiovascular disease risk factor. In contrast to such deleterious effects, UA possesses neuroprotective properties in the brain and elucidating the molecular mechanisms involved may have significant value regarding the therapeutic treatment of neurodegenerative disease. However, it is not yet fully established how UA levels are regulated in the brain. In this study, we investigated the distribution of mouse urate transporter 1 (URAT1) in the brain. URAT1 is a major reabsorptive urate transporter predominantly found in the kidney. METHODS Immunohistochemistry of wild type and URAT1 knockout mouse brain using paraffin or frozen sections and a rabbit polyclonal anti-mouse URAT1 antibody were employed. RESULTS Antibody specificity was confirmed by the lack of immunostaining in brain tissue from URAT1 knockout mice. URAT1 was distributed throughout the ventricular walls of the lateral ventricle, dorsal third ventricle, ventral third ventricle, aqueduct, and fourth ventricle, but not in the non-ciliated tanycytes in the lower part of the ventral third ventricle. URAT1 was localized to the apical membrane, including the cilia, of ependymal cells lining the wall of the ventricles that separates cerebrospinal fluid (CSF) and brain tissue. CONCLUSION In this study, we report that URAT1 is expressed on cilia and the apical surface of ventricular ependymal cells. This is the first report to demonstrate expression of the urate transporter in ventricular ependymal cells and thus raises the possibility of a novel urate transport system involving CSF.
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Affiliation(s)
| | | | | | | | | | | | - Makoto Hosoyamada
- Department of Human Physiology and Pathology, Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan.
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Toborek M, Seelbach MJ, Rashid CS, András IE, Chen L, Park M, Esser KA. Voluntary exercise protects against methamphetamine-induced oxidative stress in brain microvasculature and disruption of the blood-brain barrier. Mol Neurodegener 2013; 8:22. [PMID: 23799892 PMCID: PMC3698182 DOI: 10.1186/1750-1326-8-22] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 06/14/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is no effective therapeutic intervention developed targeting cerebrovascular toxicity of drugs of abuse, including methamphetamine (METH). We hypothesize that exercise protects against METH-induced disruption of the blood-brain barrier (BBB) by enhancing the antioxidant capacity of cerebral microvessels and modulating caveolae-associated signaling. Mice were subjected to voluntary wheel running for 5 weeks resembling the voluntary pattern of human exercise, followed by injection with METH (10 mg/kg). The frequency, duration, and intensity of each running session were monitored for each mouse via a direct data link to a computer and the running data are analyzed by Clock lab™ Analysis software. Controls included mice sedentary that did not have access to running wheels and/or injections with saline. RESULTS METH induced oxidative stress in brain microvessels, resulting in up regulation of caveolae-associated NAD(P)H oxidase subunits, and phosphorylation of mitochondrial protein 66Shc. Treatment with METH disrupted also the expression and colocalization of tight junction proteins. Importantly, exercise markedly attenuated these effects and protected against METH-induced disruption of the BBB integrity. CONCLUSIONS The obtained results indicate that exercise is an important modifiable behavioral factor that can protect against METH-induced cerebrovascular toxicity. These findings may provide new strategies in preventing the toxicity of drug of abuse.
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Omega-3 supplementation can restore glutathione levels and prevent oxidative damage caused by prenatal ethanol exposure. J Nutr Biochem 2013; 24:760-9. [DOI: 10.1016/j.jnutbio.2012.04.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 04/02/2012] [Accepted: 04/03/2012] [Indexed: 11/19/2022]
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Hall AM, Rhodes GJ, Sandoval RM, Corridon PR, Molitoris BA. In vivo multiphoton imaging of mitochondrial structure and function during acute kidney injury. Kidney Int 2013; 83:72-83. [PMID: 22992467 PMCID: PMC4136483 DOI: 10.1038/ki.2012.328] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Mitochondrial dysfunction has been implicated in the pathogenesis of acute kidney injury due to ischemia and toxic drugs. Methods for imaging mitochondrial function in cells using confocal microscopy are well established; more recently, it was shown that these techniques can be utilized in ex vivo kidney tissue using multiphoton microscopy. We extended this approach in vivo and found that kidney mitochondrial structure and function can be imaged in anesthetized rodents using multiphoton excitation of endogenous and exogenous fluorophores. Mitochondrial nicotinamide adenine dinucleotide increased markedly in rat kidneys in response to ischemia. Following intravenous injection, the mitochondrial membrane potential-dependent dye TMRM was taken up by proximal tubules; in response to ischemia, the membrane potential dissipated rapidly and mitochondria became shortened and fragmented in proximal tubules. In contrast, the mitochondrial membrane potential and structure were better maintained in distal tubules. Changes in mitochondrial structure, nicotinamide adenine dinucleotide, and membrane potential were found in the proximal, but not distal, tubules after gentamicin exposure. These changes were sporadic, highly variable among animals, and were preceded by changes in non-mitochondrial structures. Thus, real-time changes in mitochondrial structure and function can be imaged in rodent kidneys in vivo using multiphoton excitation of endogenous and exogenous fluorophores in response to ischemia-reperfusion injury or drug toxicity.
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MESH Headings
- Acute Kidney Injury/etiology
- Acute Kidney Injury/pathology
- Acute Kidney Injury/physiopathology
- Animals
- Gentamicins/adverse effects
- Glutathione/metabolism
- Ischemia/complications
- Kidney/blood supply
- Kidney Tubules, Distal/metabolism
- Kidney Tubules, Distal/pathology
- Kidney Tubules, Distal/physiopathology
- Kidney Tubules, Proximal/metabolism
- Kidney Tubules, Proximal/pathology
- Kidney Tubules, Proximal/physiopathology
- Male
- Membrane Potential, Mitochondrial/physiology
- Mice
- Mice, Inbred C57BL
- Microscopy, Fluorescence, Multiphoton/methods
- Mitochondria/pathology
- Mitochondria/physiology
- NAD/metabolism
- Rats
- Rats, Sprague-Dawley
- Rats, Wistar
- Reactive Oxygen Species/metabolism
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Affiliation(s)
- Andrew M Hall
- University College London Centre for Nephrology, Royal Free Hospital, London, UK.
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39
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Johnson S, Rabinovitch P. Ex vivo imaging of excised tissue using vital dyes and confocal microscopy. ACTA ACUST UNITED AC 2012; Chapter 9:Unit 9.39. [PMID: 22752953 DOI: 10.1002/0471142956.cy0939s61] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Vital dyes routinely used for staining cultured cells can also be used to stain and image live tissue slices ex vivo. Staining tissue with vital dyes allows researchers to collect structural and functional data simultaneously and can be used for qualitative or quantitative fluorescent image collection. The protocols presented here are useful for structural and functional analysis of viable properties of cells in intact tissue slices, allowing for the collection of data in a structurally relevant environment. With these protocols, vital dyes can be applied as a research tool to disease processes and properties of tissue not amenable to cell culture-based studies.
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40
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Ostrakhovitch EA, Semenikhin OA. The role of redox environment in neurogenic development. Arch Biochem Biophys 2012; 534:44-54. [PMID: 22910298 DOI: 10.1016/j.abb.2012.08.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 07/19/2012] [Accepted: 08/03/2012] [Indexed: 10/28/2022]
Abstract
The dynamic changes of cellular redox elements during neurogenesis allow the control of specific programs for selective lineage progression. There are many redox couples that influence the cellular redox state. The shift from a reduced to an oxidized state and vice versa may act as a cellular switch mechanism of stem cell mode of action from proliferation to differentiation. The redox homeostasis ensures proper functioning of redox-sensitive signaling pathways through oxidation/reduction of critical cysteine residues on proteins involved in signal transduction. This review presents the current knowledge on the relation between changes in the cellular redox environment and stem cell programming in the course of commitment to a restricted neural lineage, focusing on in vivo neurogenesis and in vitro neuronal differentiation. The first two sections outline the main systems that control the intracellular redox environment and make it more oxidative or reductive. The last section provides the background on redox-sensitive signaling pathways that regulate neurogenesis.
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Affiliation(s)
- E A Ostrakhovitch
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7.
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41
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Prenatal and Postnatal Epigenetic Programming: Implications for GI, Immune, and Neuronal Function in Autism. AUTISM RESEARCH AND TREATMENT 2012; 2012:190930. [PMID: 22934169 PMCID: PMC3420412 DOI: 10.1155/2012/190930] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 05/03/2012] [Indexed: 12/13/2022]
Abstract
Although autism is first and foremost a disorder of the central nervous system, comorbid dysfunction of the gastrointestinal (GI) and immune systems is common, suggesting that all three systems may be affected by common molecular mechanisms. Substantial systemic deficits in the antioxidant glutathione and its precursor, cysteine, have been documented in autism in association with oxidative stress and impaired methylation. DNA and histone methylation provide epigenetic regulation of gene expression during prenatal and postnatal development. Prenatal epigenetic programming (PrEP) can be affected by the maternal metabolic and nutritional environment, whereas postnatal epigenetic programming (PEP) importantly depends upon nutritional support provided through the GI tract. Cysteine absorption from the GI tract is a crucial determinant of antioxidant capacity, and systemic deficits of glutathione and cysteine in autism are likely to reflect impaired cysteine absorption. Excitatory amino acid transporter 3 (EAAT3) provides cysteine uptake for GI epithelial, neuronal, and immune cells, and its activity is decreased during oxidative stress. Based upon these observations, we propose that neurodevelopmental, GI, and immune aspects of autism each reflect manifestations of inadequate antioxidant capacity, secondary to impaired cysteine uptake by the GI tract. Genetic and environmental factors that adversely affect antioxidant capacity can disrupt PrEP and/or PEP, increasing vulnerability to autism.
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42
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Hackett MJ, Smith SE, Paterson PG, Nichol H, Pickering IJ, George GN. X-ray absorption spectroscopy at the sulfur K-edge: a new tool to investigate the biochemical mechanisms of neurodegeneration. ACS Chem Neurosci 2012; 3:178-85. [PMID: 22860187 PMCID: PMC3369794 DOI: 10.1021/cn200097s] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 01/02/2011] [Indexed: 12/12/2022] Open
Abstract
Sulfur containing molecules such as thiols, disulfides, sulfoxides, sulfonic acids, and sulfates may contribute to neurodegenerative processes. However, previous study in this field has been limited by the lack of in situ analytical techniques. This limitation may now be largely overcome following the development of synchrotron radiation X-ray absorption spectroscopy at the sulfur K-edge, which has been validated as a novel tool to investigate and image the speciation of sulfur in situ. In this investigation, we build the foundation required for future application of this technique to study and image the speciation of sulfur in situ within brain tissue. This study has determined the effect of sample preparation and fixation methods on the speciation of sulfur in thin sections of rat brain tissue, determined the speciation of sulfur within specific brain regions (brain stem and cerebellum), and identified sulfur specific markers of peroxidative stress following metal catalyzed reactive oxygen species production. X-ray absorption spectroscopy at the sulfur K-edge is now poised for an exciting new range of applications to study thiol redox, methionine oxidation, and the role of taurine and sulfatides during neurodegeneration.
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Affiliation(s)
- Mark J Hackett
- Molecular and Environmental Sciences Group, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatchewan S7NSE2, Canada
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43
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Brocardo PS, Boehme F, Patten A, Cox A, Gil-Mohapel J, Christie BR. Anxiety- and depression-like behaviors are accompanied by an increase in oxidative stress in a rat model of fetal alcohol spectrum disorders: Protective effects of voluntary physical exercise. Neuropharmacology 2011; 62:1607-18. [PMID: 22019722 DOI: 10.1016/j.neuropharm.2011.10.006] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 10/07/2011] [Accepted: 10/08/2011] [Indexed: 10/16/2022]
Abstract
Prenatal ethanol exposure can damage the developing nervous system, producing long-lasting impairments in both brain structure and function. In this study we analyzed how exposure to this teratogen during the period of brain development affects the intracellular redox state in the brain as well as the development of anxiety- and depressive-like phenotypes. Furthermore, we also tested whether aerobic exercise might have therapeutic potential for fetal alcohol spectrum disorders (FASD) by increasing neuronal antioxidant capacity and/or by alleviating ethanol-induced behavioral deficits. Sprague-Dawley rats were administered ethanol across all three-trimester equivalents (i.e., throughout gestation and during the first 10 days of postnatal life). Ethanol-exposed and control animals were assigned to either sedentary or running groups at postnatal day (PND) 48. Runners had free access to a running wheel for 12 days and at PND 60 anxiety- and depressive-like behaviors were assessed. Perinatal ethanol exposure resulted in the occurrence of depressive and anxiety-like behaviors in adult rats without affecting their locomotor activity. Voluntary wheel running reversed the depressive-like behaviors in ethanol-exposed males, but not in ethanol-exposed females. Levels of lipid peroxidation and protein oxidation were significantly increased in the hippocampus and cerebellum of ethanol-exposed rats, and there was a concomitant reduction in the levels of the endogenous antioxidant glutathione. Voluntary exercise was able to reverse the deficits in glutathione both in ethanol-exposed males and females. Thus, while voluntary physical exercise increased glutathione levels in both sexes, its effects at the behavioral level were sex dependent, with only ethanol-exposed male runners showing a decrease in depressive-like behaviors.
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Affiliation(s)
- Patricia S Brocardo
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, British Columbia, Canada
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44
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Narasimhan M, Mahimainathan L, Rathinam ML, Riar AK, Henderson GI. Overexpression of Nrf2 protects cerebral cortical neurons from ethanol-induced apoptotic death. Mol Pharmacol 2011; 80:988-99. [PMID: 21873460 DOI: 10.1124/mol.111.073262] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Ethanol (ETOH) can cause apoptotic death of neurons by depleting GSH with an associated increase in oxidative stress. The current study illustrates a means to overcome this ETOH-induced neurotoxicity by enhancing GSH through boosting Nrf2, a transcription factor that controls GSH homeostasis. ETOH treatment caused a significant increase in Nrf2 protein, transcript expression, Nrf2-DNA binding activity, and expression of its transcriptional target, NQO1, in primary cortical neuron (PCNs). However, this increase in Nrf2 did not maintain GSH levels in response to ETOH, and apoptotic death still occurred. To elucidate this phenomenon, we silenced Nrf2 in neurons and found that ETOH-induced GSH depletion and the increase in superoxide levels were exacerbated. Furthermore, Nrf2 knockdown resulted in significantly increased (P < 0.05) caspase 3 activity and apoptosis. Adenovirus-mediated overexpression of Nrf2 prevented ETOH-induced depletion of GSH from the medium and high GSH subpopulations and prevented ETOH-related apoptotic death. These studies illustrate the importance of Nrf2-dependent maintenance of GSH homeostasis in cerebral cortical neurons in the defense against oxidative stress and apoptotic death elicited by ETOH exposure.
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Affiliation(s)
- Madhusudhanan Narasimhan
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
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45
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Lok J, Leung W, Zhao S, Pallast S, van Leyen K, Guo S, Wang X, Yalcin A, Lo EH. γ-glutamylcysteine ethyl ester protects cerebral endothelial cells during injury and decreases blood-brain barrier permeability after experimental brain trauma. J Neurochem 2011; 118:248-55. [PMID: 21534958 DOI: 10.1111/j.1471-4159.2011.07294.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxidative stress is a pathway of injury that is common to almost all neurological conditions. Hence, methods to scavenge radicals have been extensively tested for neuroprotection. However, saving neurons alone may not be sufficient in treating CNS disease. In this study, we tested the cytoprotective actions of the glutathione precursor gamma-glutamylcysteine ethyl ester (GCEE) in brain endothelium. First, oxidative stress was induced in a human brain microvascular endothelial cell line by exposure to H(2)O(2). Addition of GCEE significantly reduced formation of reactive oxygen species, restored glutathione levels which were reduced in the presence of H(2)O(2), and decreased cell death during H(2)O(2)-mediated injury. Next, we asked whether GCEE can also protect brain endothelial cells against oxygen-glucose deprivation (OGD). As expected, OGD disrupted mitochondrial membrane potentials. GCEE was able to ameliorate these mitochondrial effects. Concomitantly, GCEE significantly decreased endothelial cell death after OGD. Lastly, our in vivo experiments using a mouse model of brain trauma show that post-trauma (10 min after controlled cortical impact) administration of GCEE by intraperitoneal injection results in a decrease in acute blood-brain barrier permeability. These data suggest that the beneficial effects of GCEE on brain endothelial cells and microvessels may contribute to its potential efficacy as a neuroprotective agent in traumatic brain injury.
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Affiliation(s)
- Josephine Lok
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
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46
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Koga M, Serritella AV, Messmer MM, Hayashi-Takagi A, Hester LD, Snyder SH, Sawa A, Sedlak TW. Glutathione is a physiologic reservoir of neuronal glutamate. Biochem Biophys Res Commun 2011; 409:596-602. [PMID: 21539809 DOI: 10.1016/j.bbrc.2011.04.087] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 04/19/2011] [Indexed: 01/04/2023]
Abstract
Glutamate, the principal excitatory neurotransmitter of the brain, participates in a multitude of physiologic and pathologic processes, including learning and memory. Glutathione, a tripeptide composed of the amino acids glutamate, cysteine, and glycine, serves important cofactor roles in antioxidant defense and drug detoxification, but glutathione deficits occur in multiple neuropsychiatric disorders. Glutathione synthesis and metabolism are governed by a cycle of enzymes, the γ-glutamyl cycle, which can achieve intracellular glutathione concentrations of 1-10mM. Because of the considerable quantity of brain glutathione and its rapid turnover, we hypothesized that glutathione may serve as a reservoir of neural glutamate. We quantified glutamate in HT22 hippocampal neurons, PC12 cells and primary cortical neurons after treatment with molecular inhibitors targeting three different enzymes of the glutathione metabolic cycle. Inhibiting 5-oxoprolinase and γ-glutamyl transferase, enzymes that liberate glutamate from glutathione, leads to decreases in glutamate. In contrast, inhibition of γ-glutamyl cysteine ligase, which uses glutamate to synthesize glutathione, results in substantial glutamate accumulation. Increased glutamate levels following inhibition of glutathione synthesis temporally precede later effects upon oxidative stress.
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Affiliation(s)
- Minori Koga
- Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Meyer 4-137, 600 North Wolfe Street, Baltimore, MD 21287, USA.
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47
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Abstract
Redox biochemistry is increasingly recognized as an integral component of cellular signal processing and cell fate decision making. Unfortunately, our capabilities to observe and measure clearly defined redox processes in the natural context of living cells, tissues, or organisms are woefully limited. The most advanced and promising tools for specific, quantitative, dynamic and compartment-specific observations are genetically encoded redox probes derived from green fluorescent protein (GFP). Within only few years from their initial introduction, redox-sensitive yellow FP (rxYFP), redox-sensitive GFPs (roGFPs), and HyPer have generated enormous interest in applying these novel tools to monitor dynamic redox changes in vivo. As genetically encoded probes, these biosensors can be specifically targeted to different subcellular locations. A critical advantage of roGFPs and HyPer is their ratiometric fluorogenic behavior. Moreover, the probe scaffold of redox-sensitive fluorescent proteins (rxYFP and roGFPs) is amenable to molecular engineering, offering fascinating prospects for further developments. In particular, the engineering of redox relays between roGFPs and redox enzymes allows control of probe specificity and enhancement of sensitivity. Genetically encoded redox probes enable the functional analysis of individual proteins in cellular redox homeostasis. In addition, redox biosensor transgenic model organisms offer extended opportunities for dynamic in vivo imaging of redox processes.
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Affiliation(s)
- Andreas J Meyer
- Heidelberg Institute for Plant Science, Heidelberg University, Heidelberg, Germany
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48
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Marí M, Colell A, Morales A, von Montfort C, Garcia-Ruiz C, Fernández-Checa JC. Redox control of liver function in health and disease. Antioxid Redox Signal 2010; 12:1295-331. [PMID: 19803748 PMCID: PMC2864660 DOI: 10.1089/ars.2009.2634] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Reactive oxygen species (ROS), a heterogeneous population of biologically active intermediates, are generated as by-products of the aerobic metabolism and exhibit a dual role in biology. When produced in controlled conditions and in limited quantities, ROS may function as signaling intermediates, contributing to critical cellular functions such as proliferation, differentiation, and cell survival. However, ROS overgeneration and, particularly, the formation of specific reactive species, inflicts cell death and tissue damage by targeting vital cellular components such as DNA, lipids, and proteins, thus arising as key players in disease pathogenesis. Given the predominant role of hepatocytes in biotransformation and metabolism of xenobiotics, ROS production constitutes an important burden in liver physiology and pathophysiology and hence in the progression of liver diseases. Despite the recognized role of ROS in disease pathogenesis, the efficacy of antioxidants as therapeutics has been limited. A better understanding of the mechanisms, nature, and location of ROS generation, as well as the optimization of cellular defense strategies, may pave the way for a brighter future for antioxidants and ROS scavengers in the therapy of liver diseases.
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Affiliation(s)
- Montserrat Marí
- Liver Unit, Hospital Clinic, IDIBAPS-CIBEK, CIBEREHD, and Department of Cell Death and Proliferation, IIBB-CSIC, Barcelona, Spain
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49
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Differential changes of glutathione levels in astrocytes and neurons in ischemic brains by two-photon imaging. J Cereb Blood Flow Metab 2010; 30:734-8. [PMID: 20104233 PMCID: PMC2848708 DOI: 10.1038/jcbfm.2010.9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Using two-photon imaging techniques with monochlorobimane as a glutathione (GSH) probe, we investigated GSH levels in both core and penumbra regions of an ischemic brain after middle cerebral artery occlusion. We found that the GSH level significantly decreased in the ischemic core, but increased significantly in the penumbra. Furthermore, we observed a differential change of the GSH levels in neurons and astrocytes in the penumbra. The GSH level in neurons increased significantly whereas it decreased slightly in astrocytes in the penumbra. These findings reveal critical region and cell type-dependent changes of the GSH level in an ischemic brain.
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50
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Lewerenz J, Albrecht P, Tien MLT, Henke N, Karumbayaram S, Kornblum HI, Wiedau-Pazos M, Schubert D, Maher P, Methner A. Induction of Nrf2 and xCT are involved in the action of the neuroprotective antibiotic ceftriaxonein vitro. J Neurochem 2009; 111:332-43. [DOI: 10.1111/j.1471-4159.2009.06347.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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