1
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Arend C, Grothaus IL, Waespy M, Ciacchi LC, Dringen R. Modulation of Multidrug Resistance Protein 1-mediated Transport Processes by the Antiviral Drug Ritonavir in Cultured Primary Astrocytes. Neurochem Res 2024; 49:66-84. [PMID: 37603214 PMCID: PMC10776481 DOI: 10.1007/s11064-023-04008-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/25/2023] [Accepted: 08/01/2023] [Indexed: 08/22/2023]
Abstract
The Multidrug Resistance Protein 1 (Mrp1) is an ATP-dependent efflux transporter and a major facilitator of drug resistance in mammalian cells during cancer and HIV therapy. In brain, Mrp1-mediated GSH export from astrocytes is the first step in the supply of GSH precursors to neurons. To reveal potential mechanisms underlying the drug-induced modulation of Mrp1-mediated transport processes, we investigated the effects of the antiviral drug ritonavir on cultured rat primary astrocytes. Ritonavir strongly stimulated the Mrp1-mediated export of glutathione (GSH) by decreasing the Km value from 200 nmol/mg to 28 nmol/mg. In contrast, ritonavir decreased the export of the other Mrp1 substrates glutathione disulfide (GSSG) and bimane-glutathione. To give explanation for these apparently contradictory observations, we performed in silico docking analysis and molecular dynamics simulations using a homology model of rat Mrp1 to predict the binding modes of ritonavir, GSH and GSSG to Mrp1. The results suggest that ritonavir binds to the hydrophilic part of the bipartite binding site of Mrp1 and thereby differently affects the binding and transport of the Mrp1 substrates. These new insights into the modulation of Mrp1-mediated export processes by ritonavir provide a new model to better understand GSH-dependent detoxification processes in brain cells.
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Affiliation(s)
- Christian Arend
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry), University of Bremen, P.O. Box 330440, 28359, Bremen, Germany.
- Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany.
| | - Isabell L Grothaus
- Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
- Hybrid Materials Interfaces Group, Faculty of Production Engineering, Bremen Center for Computational Materials Science, MAPEX Center for Materials and Processes, University of Bremen, Am Fallturm 1, 28359, Bremen, Germany
| | - Mario Waespy
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry), University of Bremen, P.O. Box 330440, 28359, Bremen, Germany
| | - Lucio Colombi Ciacchi
- Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
- Hybrid Materials Interfaces Group, Faculty of Production Engineering, Bremen Center for Computational Materials Science, MAPEX Center for Materials and Processes, University of Bremen, Am Fallturm 1, 28359, Bremen, Germany
| | - Ralf Dringen
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry), University of Bremen, P.O. Box 330440, 28359, Bremen, Germany
- Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
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2
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Mamelak M. The Alzheimer's Disease Brain, Its Microvasculature, and NADPH Oxidase. J Alzheimers Dis 2024; 99:S109-S118. [PMID: 37599534 DOI: 10.3233/jad-230415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
The deterioration of the brain's microvasculature, particularly in the hippocampus, appears to be a very early event in the development of Alzheimer's disease (AD), preceding even the deposition of amyloid-β. A damaged microvasculature reduces the supply of oxygen and glucose to this region and limits the production of energy, ATP. The damage may be a function of the rise with age in the expression and activity of NADPH oxidase (NOX) in these microvessels. This rise renders these vessels vulnerable to the effects of oxidative stress and inflammation. The rise in NOX activity with age is even more marked in the AD brain where an inverse correlation has been demonstrated between NOX activity and cognitive ability. Apocynin, a putative NOX inhibitor, has been shown to block the damaging effects of NOX activation. Apocynin acts as a strong scavenger of H2O2, and as a weak scavenger of superoxide. Like apocynin, sodium oxybate (SO) has also been shown to block the toxic effects of NOX activation. The application of SO generates NADPH and ATP. SO inhibits oxidative stress and maintains normal cerebral ATP levels under hypoxic conditions. Moreover, it acts epigenetically to attenuate the expression of NOX. SO may delay the onset and slow the progress of AD by suppling energy and maintaining an antioxidative environment in the brain throughout the night. The slow wave activity produced by SO may also activate the glymphatic system and promote the clearance of amyloid-β from the brain.
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Affiliation(s)
- Mortimer Mamelak
- Department of Psychiatry, Baycrest Hospital, University of Toronto, Toronto, Ontario, Canada
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3
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Paoli A, Cerullo G. Investigating the Link between Ketogenic Diet, NAFLD, Mitochondria, and Oxidative Stress: A Narrative Review. Antioxidants (Basel) 2023; 12:antiox12051065. [PMID: 37237931 DOI: 10.3390/antiox12051065] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/28/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
Together with the global rise in obesity and metabolic syndrome, the prevalence of individuals who suffer from nonalcoholic fatty liver disease (NAFLD) has risen dramatically. NAFLD is currently the most common chronic liver disease and includes a continuum of liver disorders from initial fat accumulation to nonalcoholic steatohepatitis (NASH), considered the more severe forms, which can evolve in, cirrhosis, and hepatocellular carcinoma. Common features of NAFLD includes altered lipid metabolism mainly linked to mitochondrial dysfunction, which, as a vicious cycle, aggravates oxidative stress and promotes inflammation and, as a consequence, the progressive death of hepatocytes and the severe form of NAFLD. A ketogenic diet (KD), i.e., a diet very low in carbohydrates (<30 g/die) that induces "physiological ketosis", has been demonstrated to alleviate oxidative stress and restore mitochondrial function. Based on this, the aim of the present review is to analyze the body of evidence regarding the potential therapeutic role of KD in NAFLD, focusing on the interplay between mitochondria and the liver, the effects of ketosis on oxidative stress pathways, and the impact of KD on liver and mitochondrial function.
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Affiliation(s)
- Antonio Paoli
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Research Center for High Performance Sport, UCAM Catholic University of Murcia, 30107 Murcia, Spain
| | - Giuseppe Cerullo
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
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4
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Rajaratnam S, Soman AP, Phalguna KS, Pradhan SS, Manjunath M, Rao RK, Dandamudi RB, Bhagavatham SKS, Pulukool SK, Rathnakumar S, Kocherlakota S, Pargaonkar A, Veeranna RP, Arumugam N, Almansour AI, Choudhary B, Sivaramakrishnan V. Integrated Omic Analysis Delineates Pathways Modulating Toxic TDP-43 Protein Aggregates in Amyotrophic Lateral Sclerosis. Cells 2023; 12:cells12091228. [PMID: 37174628 PMCID: PMC10177613 DOI: 10.3390/cells12091228] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/07/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a multi-systemic, incurable, amyloid disease affecting the motor neurons, resulting in the death of patients. The disease is either sporadic or familial with SOD1, C9orf72, FUS, and TDP-43 constituting the majority of familial ALS. Multi-omics studies on patients and model systems like mice and yeast have helped in understanding the association of various signaling and metabolic pathways with the disease. The yeast model system has played a pivotal role in elucidating the gene amyloid interactions. We carried out an integrated transcriptomic and metabolomic analysis of the TDP-43 expressing yeast model to elucidate deregulated pathways associated with the disease. The analysis shows the deregulation of the TCA cycle, single carbon metabolism, glutathione metabolism, and fatty acid metabolism. Transcriptomic analysis of GEO datasets of TDP-43 expressing motor neurons from mice models of ALS and ALS patients shows considerable overlap with experimental results. Furthermore, a yeast model was used to validate the obtained results using metabolite addition and gene knock-out experiments. Taken together, our result shows a potential role for the TCA cycle, cellular redox pathway, NAD metabolism, and fatty acid metabolism in disease. Supplementation of reduced glutathione, nicotinate, and the keto diet might help to manage the disease.
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Affiliation(s)
- Saiswaroop Rajaratnam
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur 515134, Andhra Pradesh, India
| | - Akhil P Soman
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur 515134, Andhra Pradesh, India
- Central Water and Power Research Station, Khadakwasla, Pune 411024, Maharashtra, India
| | - Kanikaram Sai Phalguna
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur 515134, Andhra Pradesh, India
| | - Sai Sanwid Pradhan
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur 515134, Andhra Pradesh, India
| | - Meghana Manjunath
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru 560100, Karnataka, India
| | - Raksha Kanthavara Rao
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru 560100, Karnataka, India
| | | | - Sai Krishna Srimadh Bhagavatham
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur 515134, Andhra Pradesh, India
| | - Sujith Kumar Pulukool
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur 515134, Andhra Pradesh, India
| | - Sriram Rathnakumar
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur 515134, Andhra Pradesh, India
| | - Sai Kocherlakota
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Ashish Pargaonkar
- Application Division, Agilent Technologies Ltd., Bengaluru 560066, Karnataka, India
| | - Ravindra P Veeranna
- Department of Biochemistry, Council of Scientific & Industrial Research (CSIR)-Central Food Technological Research Institute (CFTRI), Mysuru 570020, Karnataka, India
| | - Natarajan Arumugam
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Abdulrahman I Almansour
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Bibha Choudhary
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru 560100, Karnataka, India
| | - Venketesh Sivaramakrishnan
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur 515134, Andhra Pradesh, India
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5
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Reza Sepand M, Bigdelou B, Salek Maghsoudi A, Sanadgol N, Ho JQ, Chauhan P, Raoufi M, Kermanian A, Esfandyarpour R, Javad Hajipour M, Zanganeh S. Ferroptosis: Environmental causes, biological redox signaling responses, cancer and other health consequences. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2023.215024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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6
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Chang H, Bennett AM, Cameron WD, Floro E, Au A, McFaul CM, Yip CM, Rocheleau JV. Targeting Apollo-NADP + to Image NADPH Generation in Pancreatic Beta-Cell Organelles. ACS Sens 2022; 7:3308-3317. [PMID: 36269889 PMCID: PMC9706804 DOI: 10.1021/acssensors.2c01174] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
NADPH/NADP+ redox state supports numerous reactions related to cell growth and survival; yet the full impact is difficult to appreciate due to organelle compartmentalization of NADPH and NADP+. To study glucose-stimulated NADPH production in pancreatic beta-cell organelles, we targeted the Apollo-NADP+ sensor by first selecting the most pH-stable version of the single-color sensor. We subsequently targeted mTurquoise2-Apollo-NADP+ to various organelles and confirmed activity in the cytoplasm, mitochondrial matrix, nucleus, and peroxisome. Finally, we measured the glucose- and glutamine-stimulated NADPH responses by single- and dual-color imaging of the targeted sensors. Overall, we developed multiple organelle-targeted Apollo-NADP+ sensors to reveal the prominent role of beta-cell mitochondria in determining NADPH production in the cytoplasm, nucleus, and peroxisome.
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Affiliation(s)
- Huntley
H. Chang
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Alex M. Bennett
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada
| | - William D. Cameron
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Eric Floro
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Aaron Au
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Christopher M. McFaul
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Christopher M. Yip
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Jonathan V. Rocheleau
- Institute
of Biomedical Engineering, University of
Toronto, Toronto, Ontario M5S 3G9, Canada,Toronto
General Hospital Research Institute, University
Health Network, Toronto, Ontario M5G 2C4, Canada,Department
of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada,Banting
and Best Diabetes Centre, University of
Toronto, Toronto, Ontario M5G 2C4, Canada,
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7
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Scott MB, Styring AK, McCullagh JSO. Polyphenols: Bioavailability, Microbiome Interactions and Cellular Effects on Health in Humans and Animals. Pathogens 2022; 11:pathogens11070770. [PMID: 35890016 PMCID: PMC9324685 DOI: 10.3390/pathogens11070770] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/26/2022] [Accepted: 07/03/2022] [Indexed: 12/12/2022] Open
Abstract
Polyphenolic compounds have a variety of functions in plants including protecting them from a range of abiotic and biotic stresses such as pathogenic infections, ionising radiation and as signalling molecules. They are common constituents of human and animal diets, undergoing extensive metabolism by gut microbiota in many cases prior to entering circulation. They are linked to a range of positive health effects, including anti-oxidant, anti-inflammatory, antibiotic and disease-specific activities but the relationships between polyphenol bio-transformation products and their interactions in vivo are less well understood. Here we review the state of knowledge in this area, specifically what happens to dietary polyphenols after ingestion and how this is linked to health effects in humans and animals; paying particular attention to farm animals and pigs. We focus on the chemical transformation of polyphenols after ingestion, through microbial transformation, conjugation, absorption, entry into circulation and uptake by cells and tissues, focusing on recent findings in relation to bone. We review what is known about how these processes affect polyphenol bioactivity, highlighting gaps in knowledge. The implications of extending the use of polyphenols to treat specific pathogenic infections and other illnesses is explored.
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Affiliation(s)
- Michael B. Scott
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK;
- School of Archaeology, University of Oxford, Oxford OX1 3TG, UK;
| | - Amy K. Styring
- School of Archaeology, University of Oxford, Oxford OX1 3TG, UK;
| | - James S. O. McCullagh
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK;
- Correspondence:
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8
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Francisco A, Figueira TR, Castilho RF. Mitochondrial NAD(P) + Transhydrogenase: From Molecular Features to Physiology and Disease. Antioxid Redox Signal 2022; 36:864-884. [PMID: 34155914 DOI: 10.1089/ars.2021.0111] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Significance: Proton-translocating NAD(P)+ transhydrogenase, also known as nicotinamide nucleotide transhydrogenase (NNT), catalyzes a reversible reaction coupling the protonmotive force across the inner mitochondrial membrane and hydride (H-, a proton plus two electrons) transfer between the mitochondrial pools of NAD(H) and NADP(H). The forward NNT reaction is a source of NADPH in the mitochondrial matrix, fueling antioxidant and biosynthetic pathways with reductive potential. Despite the greater emphasis given to the net forward reaction, the reverse NNT reaction that oxidizes NADPH also occurs in physiological and pathological conditions. Recent Advances: NNT (dys)function has been linked to various metabolic pathways and disease phenotypes. Most of these findings have been based on spontaneous loss-of-function Nnt mutations found in the C57BL/6J mouse strain (NntC57BL/6J mutation) and disease-causing Nnt mutations in humans. The present review focuses on recent advances based on the mouse NntC57BL/6J mutation. Critical Issues: Most studies associating NNT function with disease phenotypes have been based on comparisons between different strains of inbred mice (with or without the NntC57BL/6J mutation), which creates uncertainties over the actual contribution of NNT in the context of other potential genetic modifiers. Future Directions: Future research might contribute to understanding the role of NNT in pathological conditions and elucidate how NNT regulates physiological signaling through its forward and reverse reactions. The importance of NNT in redox balance and tumor cell proliferation makes it a potential target of new therapeutic strategies for oxidative-stress-mediated diseases and cancer. Antioxid. Redox Signal. 36, 864-884.
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Affiliation(s)
- Annelise Francisco
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Tiago Rezende Figueira
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Roger Frigério Castilho
- Department of Pathology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
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9
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The Effects of Contrast between Dark- and Light-Coloured Tanks on the Growth Performance and Antioxidant Parameters of Juvenile European Perch (Perca fluviatilis). WATER 2022. [DOI: 10.3390/w14060969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
European perch (Perca fluviatilis) is a predatory fish species with a high degree of stress sensitivity during rearing in intensive systems. Our study was focused on the effects of contrast between two colours (black and light grey) in different parts of a tank (bottom and sidewall) on the production and antioxidant parameters of juvenile European perch during intensive rearing. The duration of the experiment was 8 weeks. In the first treatment, the bottoms of the tanks were black (DB); in the second treatment, the sides of the tank were black (DS); in the control treatment, the fish were kept in light-grey tanks (K). There were three replicates per treatment, and a total of 180 individuals were used; therefore, 60 individuals were used per treatment, with 20 individuals per tank. The mean body weight of the fish at the start of the experiment was 32.01 ± 0.79 g. At the end of the experiment, the antioxidant parameters (cortisol, glucose, MDA, catalase, vitamin C, GPx, GR, GSH, GSSG, and HSP70) of the fish were determined from blood samples. The results of our experiment show that different levels of contrast between the dark and light tank colours significantly influenced the production and antioxidant parameters of the juvenile European perch.
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10
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Prevention of Lipotoxicity in Pancreatic Islets with Gammahydroxybutyrate. Cells 2022; 11:cells11030545. [PMID: 35159354 PMCID: PMC8833960 DOI: 10.3390/cells11030545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/28/2022] [Accepted: 01/30/2022] [Indexed: 02/06/2023] Open
Abstract
Oxidative stress caused by the exposure of pancreatic ß-cells to high levels of fatty acids impairs insulin secretion. This lipotoxicity is thought to play an important role in ß-cell failure in type 2 diabetes and can be prevented by antioxidants. Gamma-hydroxybutyrate (GHB), an endogenous antioxidant and energy source, has previously been shown to protect mice from streptozotocin and alloxan-induced diabetes; both compounds are generators of oxidative stress and yield models of type-1 diabetes. We sought to determine whether GHB could protect mouse islets from lipotoxicity caused by palmitate, a model relevant to type 2 diabetes. We found that GHB prevented the generation of palmitate-induced reactive oxygen species and the associated lipotoxic inhibition of glucose-stimulated insulin secretion while increasing the NADPH/NADP+ ratio. GHB may owe its antioxidant and insulin secretory effects to the formation of NADPH.
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11
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Kumar R, Jafri MS. Computational Modeling of Mitochondria to Understand the Dynamics of Oxidative Stress. Methods Mol Biol 2022; 2497:363-422. [PMID: 35771458 PMCID: PMC9811848 DOI: 10.1007/978-1-0716-2309-1_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Mitochondria are complex organelles that use catabolic metabolism to produce ATP which is the critical energy source for cell function. Oxidative phosphorylation by the electron transport chain, which receives reducing equivalents (NADH and FADH2) from the tricarboxylic acid cycle, also produces reactive oxygen species (ROS) as a by-product at complex I and III. ROS play a significant role in health and disease. In order to better understand this process, a computational model of mitochondrial energy metabolism and the production of ROS has been developed. The model demonstrates the process regulating ROS production and removal and how different energy substrates can affect ROS production.
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Affiliation(s)
- Rashmi Kumar
- School of Systems Biology, George Mason University, Fairfax, VA, USA
| | - Mohsin S Jafri
- School of Systems Biology, George Mason University, Fairfax, VA, USA.
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA.
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12
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Sterling JP, Lombardi VC. Decreasing the Likelihood of Multiple Organ Dysfunction Syndrome in Burn Injury with Early Antioxidant Treatment. Antioxidants (Basel) 2021; 10:antiox10081192. [PMID: 34439439 PMCID: PMC8389021 DOI: 10.3390/antiox10081192] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 01/21/2023] Open
Abstract
Major burn trauma initiates a cascade of physiological events that cause profound stress on the body, resulting in significant complications which often lead to death. An understanding of these events may afford earlier and more precise interventions which, in turn, may reduce these complications, thus, improving patient outcomes. Burn trauma is associated with numerous inflammatory events that result in the release of free radicals, which promote oxidative stress and subsequent tissue damage. These mass-inflammatory events affect the body systemically, leading to several detrimental responses including complement activation, excessive histamine release, decrease in blood pressure, release of reactive oxygen species, and ultimately multiple organ dysfunction syndrome (MODS). However, recent studies conducted on the use of antioxidants as a part of a burn treatment protocol have shown promising results. In this review, we will discuss the current research and advancements in the treatment of burn trauma with the use of antioxidants, and how the early administration of antioxidant can possibly reduce the risk of developing MODS.
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Affiliation(s)
| | - Vincent C. Lombardi
- Department of Microbiology and Immunology, University of Nevada, Reno, School of Medicine, Reno, NV 89557, USA
- Correspondence: ; Tel.: +1-775-682-8278
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13
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Mamelak M. Sleep, Narcolepsy, and Sodium Oxybate. Curr Neuropharmacol 2021; 20:272-291. [PMID: 33827411 PMCID: PMC9413790 DOI: 10.2174/1570159x19666210407151227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 11/23/2022] Open
Abstract
Sodium oxybate (SO) has been in use for many decades to treat narcolepsy with cataplexy. It functions as a weak GABAB agonist but also as an energy source for the brain as a result of its metabolism to succinate and as a powerful antioxidant because of its capacity to induce the formation of NADPH. Its actions at thalamic GABAB receptors can induce slow-wave activity, while its actions at GABAB receptors on monoaminergic neurons can induce or delay REM sleep. By altering the balance between monoaminergic and cholinergic neuronal activity, SO uniquely can induce and prevent cataplexy. The formation of NADPH may enhance sleep’s restorative process by accelerating the removal of the reactive oxygen species (ROS), which accumulate during wakefulness. SO improves alertness in normal subjects and in patients with narcolepsy. SO may allay severe psychological stress - an inflammatory state triggered by increased levels of ROS and characterized by cholinergic supersensitivity and monoaminergic deficiency. SO may be able to eliminate the inflammatory state and correct the cholinergic/ monoaminergic imbalance.
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Affiliation(s)
- Mortimer Mamelak
- Department of Psychiatry, Baycrest Hospital, University of Toronto, Toronto, Ontario. Canada
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14
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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: 66] [Impact Index Per Article: 16.5] [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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15
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Jeong H, Vacanti NM. Systemic vitamin intake impacting tissue proteomes. Nutr Metab (Lond) 2020; 17:73. [PMID: 32863845 PMCID: PMC7449053 DOI: 10.1186/s12986-020-00491-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 08/07/2020] [Indexed: 12/12/2022] Open
Abstract
The kinetics and localization of the reactions of metabolism are coordinated by the enzymes that catalyze them. These enzymes are controlled via a myriad of mechanisms including inhibition/activation by metabolites, compartmentalization, thermodynamics, and nutrient sensing-based transcriptional or post-translational regulation; all of which are influenced as a network by the activities of metabolic enzymes and have downstream potential to exert direct or indirect control over protein abundances. Considering many of these enzymes are active only when one or more vitamin cofactors are present; the availability of vitamin cofactors likely yields a systems-influence over tissue proteomes. Furthermore, vitamins may influence protein abundances as nuclear receptor agonists, antioxidants, substrates for post-translational modifications, molecular signal transducers, and regulators of electrolyte homeostasis. Herein, studies of vitamin intake are explored for their contribution to unraveling vitamin influence over protein expression. As a body of work, these studies establish vitamin intake as a regulator of protein abundance; with the most powerful demonstrations reporting regulation of proteins directly related to the vitamin of interest. However, as a whole, the field has not kept pace with advances in proteomic platforms and analytical methodologies, and has not moved to validate mechanisms of regulation or potential for clinical application.
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Affiliation(s)
- Heesoo Jeong
- Division of Nutritional Sciences, Cornell University, Ithaca, NY USA
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16
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A novel role for the glutamate decarboxylase system in Listeria monocytogenes; protection against oxidative stress. Food Microbiol 2020; 85:103284. [DOI: 10.1016/j.fm.2019.103284] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 07/30/2019] [Indexed: 12/17/2022]
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17
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Francisco A, Ronchi JA, Navarro CDC, Figueira TR, Castilho RF. Nicotinamide nucleotide transhydrogenase is required for brain mitochondrial redox balance under hampered energy substrate metabolism and high-fat diet. J Neurochem 2018; 147:663-677. [PMID: 30281804 DOI: 10.1111/jnc.14602] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/13/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022]
Abstract
Among mitochondrial NADP-reducing enzymes, nicotinamide nucleotide transhydrogenase (NNT) establishes an elevated matrix NADPH/NADP+ by catalyzing the reduction of NADP+ at the expense of NADH oxidation coupled to inward proton translocation across the inner mitochondrial membrane. Here, we characterize NNT activity and mitochondrial redox balance in the brain using a congenic mouse model carrying the mutated Nnt gene from the C57BL/6J strain. The absence of NNT activity resulted in lower total NADPH sources activity in the brain mitochondria of young mice, an effect that was partially compensated in aged mice. Nonsynaptic mitochondria showed higher NNT activity than synaptic mitochondria. In the absence of NNT, an increased release of H2 O2 from mitochondria was observed when the metabolism of respiratory substrates occurred with restricted flux through relevant mitochondrial NADPH sources or when respiratory complex I was inhibited. In accordance, mitochondria from Nnt-/- brains were unable to sustain NADP in its reduced state when energized in the absence of carbon substrates, an effect aggravated after H2 O2 bolus metabolism. These data indicate that the lack of NNT in brain mitochondria impairs peroxide detoxification, but peroxide detoxification can be partially counterbalanced by concurrent NADPH sources depending on substrate availability. Notably, only brain mitochondria from Nnt-/- mice chronically fed a high-fat diet exhibited lower activity of the redox-sensitive aconitase, suggesting that brain mitochondrial redox balance requires NNT under the metabolic stress of a high-fat diet. Overall, the role of NNT in the brain mitochondria redox balance especially comes into play under mitochondrial respiratory defects or high-fat diet.
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Affiliation(s)
- Annelise Francisco
- Faculty of Medical Sciences, Department of Clinical Pathology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Juliana A Ronchi
- Faculty of Medical Sciences, Department of Clinical Pathology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Claudia D C Navarro
- Faculty of Medical Sciences, Department of Clinical Pathology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Tiago R Figueira
- Faculty of Medical Sciences, Department of Clinical Pathology, University of Campinas (UNICAMP), Campinas, SP, Brazil.,School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Roger F Castilho
- Faculty of Medical Sciences, Department of Clinical Pathology, University of Campinas (UNICAMP), Campinas, SP, Brazil
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18
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Raabe J, Arend C, Steinmeier J, Dringen R. Dicoumarol Inhibits Multidrug Resistance Protein 1-Mediated Export Processes in Cultured Primary Rat Astrocytes. Neurochem Res 2018; 44:333-346. [PMID: 30443714 DOI: 10.1007/s11064-018-2680-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/05/2018] [Accepted: 11/08/2018] [Indexed: 12/13/2022]
Abstract
Dicoumarol is frequently used as inhibitor of the detoxifying enzyme NAD(P)H:quinone acceptor oxidoreductase 1 (NQO1). In order to test whether dicoumarol may also affect the cellular glutathione (GSH) metabolism, we have exposed cultured primary astrocytes to dicoumarol and investigated potential effects of this compound on the cell viability as well as on the cellular and extracellular contents of GSH and its metabolites. Incubation of astrocytes with dicoumarol in concentrations of up to 100 µM did not acutely compromise cell viability nor was any GSH consumption or GSH oxidation to glutathione disulfide (GSSG) observed. However, unexpectedly dicoumarol inhibited the cellular multidrug resistance protein (Mrp) 1-dependent export of GSH in a time- and concentration-dependent manner with half-maximal effects observed at low micromolar concentrations of dicoumarol. Inhibition of GSH export by dicoumarol was not additive to that observed for the known Mrp1 inhibitor MK571. In addition, dicoumarol inhibited also the Mrp1-mediated export of GSSG during menadione-induced oxidative stress and the export of the GSH-bimane-conjugate (GS-B) that had been generated in the cells after exposure to monochlorobimane. Half-maximal inhibition of the export of Mrp1 substrates was observed at dicoumarol concentrations of around 4 µM (GSH and GSSG) and 30 µM (GS-B). These data demonstrate that dicoumarol strongly affects the GSH metabolism of viable cultured astrocytes by inhibiting Mrp1-mediated export processes and identifies for the first time Mrp1 as additional cellular target of dicoumarol.
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Affiliation(s)
- Janice Raabe
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry), University of Bremen, P.O. Box 330440, 28334, Bremen, Germany
| | - Christian Arend
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry), University of Bremen, P.O. Box 330440, 28334, Bremen, Germany.,Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
| | - Johann Steinmeier
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry), University of Bremen, P.O. Box 330440, 28334, Bremen, Germany.,Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
| | - Ralf Dringen
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry), University of Bremen, P.O. Box 330440, 28334, Bremen, Germany. .,Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany.
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19
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McCracken JM, Chalise P, Briley SM, Dennis KL, Jiang L, Duncan FE, Pritchard MT. C57BL/6 Substrains Exhibit Different Responses to Acute Carbon Tetrachloride Exposure: Implications for Work Involving Transgenic Mice. Gene Expr 2017; 17:187-205. [PMID: 28234577 PMCID: PMC5500426 DOI: 10.3727/105221617x695050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Biological differences exist between strains of laboratory mice, and it is becoming increasingly evident that there are differences between substrains. In the C57BL/6 mouse, the primary substrains are called 6J and 6N. Previous studies have demonstrated that 6J and 6N mice differ in response to many experimental models of human disease. The aim of our study was to determine if differences exist between 6J and 6N mice in terms of their response to acute carbon tetrachloride (CCl4) exposure. Mice were given CCl4 once and were euthanized 12 to 96 h later. Relative to 6J mice, we found that 6N mice had increased liver injury but more rapid repair. This was because of the increased speed with which necrotic hepatocytes were removed in 6N mice and was directly related to increased recruitment of macrophages to the liver. In parallel, enhanced liver regeneration was observed in 6N relative to 6J mice. Hepatic stellate cell activation occurred earlier in 6N mice, but there was no difference in matrix metabolism between substrains. Taken together, these data demonstrate specific and significant differences in how the C57BL/6 substrains respond to acute CCl4, which has important implications for all mouse studies utilizing this model.
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Affiliation(s)
- Jennifer M. McCracken
- *Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
| | - Prabhakar Chalise
- †Department of Biostatistics, University of Kansas Medical Center, Kansas City, KS, USA
| | - Shawn M. Briley
- ‡Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Katie L. Dennis
- §Department of Pathology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Lu Jiang
- *Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
| | - Francesca E. Duncan
- ‡Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Michele T. Pritchard
- *Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
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20
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Di Meo S, Iossa S, Venditti P. Skeletal muscle insulin resistance: role of mitochondria and other ROS sources. J Endocrinol 2017; 233:R15-R42. [PMID: 28232636 DOI: 10.1530/joe-16-0598] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 01/31/2017] [Indexed: 12/12/2022]
Abstract
At present, obesity is one of the most important public health problems in the world because it causes several diseases and reduces life expectancy. Although it is well known that insulin resistance plays a pivotal role in the development of type 2 diabetes mellitus (the more frequent disease in obese people) the link between obesity and insulin resistance is yet a matter of debate. One of the most deleterious effects of obesity is the deposition of lipids in non-adipose tissues when the capacity of adipose tissue is overwhelmed. During the last decade, reduced mitochondrial function has been considered as an important contributor to 'toxic' lipid metabolite accumulation and consequent insulin resistance. More recent reports suggest that mitochondrial dysfunction is not an early event in the development of insulin resistance, but rather a complication of the hyperlipidemia-induced reactive oxygen species (ROS) production in skeletal muscle, which might promote mitochondrial alterations, lipid accumulation and inhibition of insulin action. Here, we review the literature dealing with the mitochondria-centered mechanisms proposed to explain the onset of obesity-linked IR in skeletal muscle. We conclude that the different pathways leading to insulin resistance may act synergistically because ROS production by mitochondria and other sources can result in mitochondrial dysfunction, which in turn can further increase ROS production leading to the establishment of a harmful positive feedback loop.
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Affiliation(s)
- Sergio Di Meo
- Department of BiologyUniversity of Naples 'Federico II', Naples, Italy
| | - Susanna Iossa
- Department of BiologyUniversity of Naples 'Federico II', Naples, Italy
| | - Paola Venditti
- Department of BiologyUniversity of Naples 'Federico II', Naples, Italy
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21
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Naseri NN, Bonica J, Xu H, Park LC, Arjomand J, Chen Z, Gibson GE. Novel Metabolic Abnormalities in the Tricarboxylic Acid Cycle in Peripheral Cells From Huntington's Disease Patients. PLoS One 2016; 11:e0160384. [PMID: 27611087 PMCID: PMC5017661 DOI: 10.1371/journal.pone.0160384] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 07/18/2016] [Indexed: 12/12/2022] Open
Abstract
Metabolic dysfunction is well-documented in Huntington's disease (HD). However, the link between the mutant huntingtin (mHTT) gene and the pathology is unknown. The tricarboxylic acid (TCA) cycle is the main metabolic pathway for the production of NADH for conversion to ATP via the electron transport chain (ETC). The objective of this study was to test for differences in enzyme activities, mRNAs and protein levels related to the TCA cycle between lymphoblasts from healthy subjects and from patients with HD. The experiments utilize the advantages of lymphoblasts to reveal new insights about HD. The large quantity of homogeneous cell populations permits multiple dynamic measures to be made on exactly comparable tissues. The activities of nine enzymes related to the TCA cycle and the expression of twenty-nine mRNAs encoding for these enzymes and enzyme complexes were measured. Cells were studied under baseline conditions and during metabolic stress. The results support our recent findings that the activities of the pyruvate dehydrogenase complex (PDHC) and succinate dehydrogenase (SDH) are elevated in HD. The data also show a large unexpected depression in MDH activities. Furthermore, message levels for isocitrate dehydrogenase 1 (IDH1) were markedly increased in in HD lymphoblasts and were responsive to treatments. The use of lymphoblasts allowed us to clarify that the reported decrease in aconitase activity in HD autopsy brains is likely due to secondary hypoxic effects. These results demonstrate the mRNA and enzymes of the TCA cycle are critical therapeutic targets that have been understudied in HD.
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Affiliation(s)
- Nima N. Naseri
- Weill Cornell Medical College, Brain and Mind Research Institute, Burke Medical Research Institute, 785 Mamaroneck Avenue, White Plains, NY 10605, United States of America
| | - Joseph Bonica
- Weill Cornell Medical College, Brain and Mind Research Institute, Burke Medical Research Institute, 785 Mamaroneck Avenue, White Plains, NY 10605, United States of America
| | - Hui Xu
- Weill Cornell Medical College, Brain and Mind Research Institute, Burke Medical Research Institute, 785 Mamaroneck Avenue, White Plains, NY 10605, United States of America
| | - Larry C. Park
- CHDI Management/CHDI Foundation, Inc., 6080 Center Drive. Suite 100, Los Angeles, CA 90045, United States of America
| | - Jamshid Arjomand
- CHDI Management/CHDI Foundation, Inc., 6080 Center Drive. Suite 100, Los Angeles, CA 90045, United States of America
| | - Zhengming Chen
- Weill Cornell Medical College, Division of Biostatistics and Epidemiology, Department of Healthcare Policy and Research, 425 East 61st Street, New York, NY 10065, United States of America
| | - Gary E. Gibson
- Weill Cornell Medical College, Brain and Mind Research Institute, Burke Medical Research Institute, 785 Mamaroneck Avenue, White Plains, NY 10605, United States of America
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22
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Ronchi JA, Francisco A, Passos LAC, Figueira TR, Castilho RF. The Contribution of Nicotinamide Nucleotide Transhydrogenase to Peroxide Detoxification Is Dependent on the Respiratory State and Counterbalanced by Other Sources of NADPH in Liver Mitochondria. J Biol Chem 2016; 291:20173-87. [PMID: 27474736 DOI: 10.1074/jbc.m116.730473] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Indexed: 11/06/2022] Open
Abstract
The forward reaction of nicotinamide nucleotide transhydrogenase (NNT) reduces NADP(+) at the expense of NADH oxidation and H(+) movement down the electrochemical potential across the inner mitochondrial membrane, establishing an NADPH/NADP(+) ratio severalfold higher than the NADH/NAD(+) ratio in the matrix. In turn, NADPH drives processes, such as peroxide detoxification and reductive biosynthesis. In this study, we generated a congenic mouse model carrying a mutated Nnt(C57BL/6J) allele from the C57BL/6J substrain. Suspensions of isolated mitochondria from Nnt(+/+), Nnt(+/-), and Nnt(-/-) mouse liver were biochemically evaluated and challenged with exogenous peroxide under different respiratory states. The respiratory substrates were also varied, and the participation of concurrent NADPH sources (i.e. isocitrate dehydrogenase-2, malic enzymes, and glutamate dehydrogenase) was assessed. The principal findings include the following: Nnt(+/-) and Nnt(-/-) exhibit ∼50% and absent NNT activity, respectively, but the activities of concurrent NADPH sources are unchanged. The lack of NNT activity in Nnt(-/-) mice impairs peroxide metabolism in intact mitochondria. The contribution of NNT to peroxide metabolism is decreased during ADP phosphorylation compared with the non-phosphorylating state; however, it is accompanied by increased contributions of concurrent NADPH sources, especially glutamate dehydrogenase. NNT makes a major contribution to peroxide metabolism during the blockage of mitochondrial electron transport. Interestingly, peroxide metabolism in the Nnt(+/-) mitochondria matched that in the Nnt(+/+) mitochondria. Overall, this study demonstrates that the respiratory state and/or substrates that sustain energy metabolism markedly influence the relative contribution of NNT (i.e. varies between nearly 0 and 100%) to NADPH-dependent mitochondrial peroxide metabolism.
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Affiliation(s)
| | - Annelise Francisco
- From the Department of Clinical Pathology, Faculty of Medical Sciences, and
| | - Luiz Augusto Correa Passos
- Multidisciplinary Center for Biological Investigation on Laboratory Animals Science, University of Campinas, Campinas SP 13083-877, Brazil
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23
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The Role of Mitochondrial Reactive Oxygen Species in Cardiovascular Injury and Protective Strategies. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:8254942. [PMID: 27200148 PMCID: PMC4856919 DOI: 10.1155/2016/8254942] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 12/14/2022]
Abstract
Ischaemia/reperfusion (I/R) injury of the heart represents a major health burden mainly associated with acute coronary syndromes. While timely coronary reperfusion has become the established routine therapy in patients with ST-elevation myocardial infarction, the restoration of blood flow into the previously ischaemic area is always accompanied by myocardial injury. The central mechanism involved in this phenomenon is represented by the excessive generation of reactive oxygen species (ROS). Besides their harmful role when highly generated during early reperfusion, minimal ROS formation during ischaemia and/or at reperfusion is critical for the redox signaling of cardioprotection. In the past decades, mitochondria have emerged as the major source of ROS as well as a critical target for cardioprotective strategies at reperfusion. Mitochondria dysfunction associated with I/R myocardial injury is further described and ultimately analyzed with respect to its role as source of both deleterious and beneficial ROS. Furthermore, the contribution of ROS in the highly investigated field of conditioning strategies is analyzed. In the end, the vascular sources of mitochondria-derived ROS are briefly reviewed.
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24
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Divalent cation chelators citrate and EDTA unmask an intrinsic uncoupling pathway in isolated mitochondria. J Bioenerg Biomembr 2016; 49:3-11. [PMID: 26971498 DOI: 10.1007/s10863-016-9656-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/07/2016] [Indexed: 10/22/2022]
Abstract
We demonstrate a suppression of ROS production and uncoupling of mitochondria by exogenous citrate in Mg2+ free medium. Exogenous citrate suppressed H2O2 emission and depolarized mitochondria. The depolarization was paralleled by the stimulation of respiration of mitochondria. The uncoupling action of citrate was independent of the presence of sodium, potassium, or chlorine ions, and it was not mediated by the changes in permeability of the inner mitochondrial membrane to solutes. The citrate transporter was not involved in the citrate effect. Inhibitory analysis data indicated that several well described mitochondria carriers and channels (ATPase, IMAC, ADP/ATP translocase, mPTP, mKATP) were not involved in citrate's effect. Exogenous MgCl2 strongly inhibited citrate-induced depolarization. The uncoupling effect of citrate was demonstrated in rat brain, mouse brain, mouse liver, and human melanoma cells mitochondria. We interpreted the data as an evidence to the existence of a hitherto undescribed putative inner mitochondrial membrane channel that is regulated by extramitochondrial Mg2+ or other divalent cations.
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25
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Succinate, an intermediate in metabolism, signal transduction, ROS, hypoxia, and tumorigenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1086-1101. [PMID: 26971832 DOI: 10.1016/j.bbabio.2016.03.012] [Citation(s) in RCA: 315] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/06/2016] [Accepted: 03/07/2016] [Indexed: 12/31/2022]
Abstract
Succinate is an important metabolite at the cross-road of several metabolic pathways, also involved in the formation and elimination of reactive oxygen species. However, it is becoming increasingly apparent that its realm extends to epigenetics, tumorigenesis, signal transduction, endo- and paracrine modulation and inflammation. Here we review the pathways encompassing succinate as a metabolite or a signal and how these may interact in normal and pathological conditions.(1).
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26
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Andreyev AY, Kushnareva YE, Murphy AN, Starkov AA. Mitochondrial ROS Metabolism: 10 Years Later. BIOCHEMISTRY (MOSCOW) 2016; 80:517-31. [PMID: 26071769 DOI: 10.1134/s0006297915050028] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The role of mitochondria in oxidative stress is well recognized, but many questions are still to be answered. This article is intended to update our comprehensive review in 2005 by highlighting the progress in understanding of mitochondrial reactive oxygen species (ROS) metabolism over the past 10 years. We review the recently identified or re-appraised sources of ROS generation in mitochondria, such as p66(shc) protein, succinate dehydrogenase, and recently discovered properties of the mitochondrial antioxidant system. We also reflect upon some controversies, disputes, and misconceptions that confound the field.
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Affiliation(s)
- A Y Andreyev
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093-0601, USA.
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27
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Glucose, Lactate, β-Hydroxybutyrate, Acetate, GABA, and Succinate as Substrates for Synthesis of Glutamate and GABA in the Glutamine-Glutamate/GABA Cycle. ADVANCES IN NEUROBIOLOGY 2016; 13:9-42. [PMID: 27885625 DOI: 10.1007/978-3-319-45096-4_2] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The glutamine-glutamate/GABA cycle is an astrocytic-neuronal pathway transferring precursors for transmitter glutamate and GABA from astrocytes to neurons. In addition, the cycle carries released transmitter back to astrocytes, where a minor fraction (~25 %) is degraded (requiring a similar amount of resynthesis) and the remainder returned to the neurons for reuse. The flux in the cycle is intense, amounting to the same value as neuronal glucose utilization rate or 75-80 % of total cortical glucose consumption. This glucose:glutamate ratio is reduced when high amounts of β-hydroxybutyrate are present, but β-hydroxybutyrate can at most replace 60 % of glucose during awake brain function. The cycle is initiated by α-ketoglutarate production in astrocytes and its conversion via glutamate to glutamine which is released. A crucial reaction in the cycle is metabolism of glutamine after its accumulation in neurons. In glutamatergic neurons all generated glutamate enters the mitochondria and its exit to the cytosol occurs in a process resembling the malate-aspartate shuttle and therefore requiring concomitant pyruvate metabolism. In GABAergic neurons one half enters the mitochondria, whereas the other one half is released directly from the cytosol. A revised concept is proposed for the synthesis and metabolism of vesicular and nonvesicular GABA. It includes the well-established neuronal GABA reuptake, its metabolism, and use for resynthesis of vesicular GABA. In contrast, mitochondrial glutamate is by transamination to α-ketoglutarate and subsequent retransamination to releasable glutamate essential for the transaminations occurring during metabolism of accumulated GABA and subsequent resynthesis of vesicular GABA.
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28
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Yin B, Barrionuevo G, Weber SG. Optimized real-time monitoring of glutathione redox status in single pyramidal neurons in organotypic hippocampal slices during oxygen-glucose deprivation and reperfusion. ACS Chem Neurosci 2015; 6:1838-48. [PMID: 26291433 DOI: 10.1021/acschemneuro.5b00186] [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] [Indexed: 02/07/2023] Open
Abstract
A redox-sensitive Grx1-roGFP2 fusion protein was introduced by transfection into single pyramidal neurons in the CA1 subfield of organotypic hippocampal slice cultures (OHSCs). We assessed changes in the GSH system in neuronal cytoplasm and mitochondria during oxygen-glucose deprivation and reperfusion (OGD/RP), an in vitro model of stroke. Pyramidal cells in a narrow range of depths below the surface of the OHSC were transfected by gene gun or single-cell electroporation with cyto- or mito-Grx1-roGFP2. To mimic the conditions of acute stroke, we developed an optimized superfusion system with the capability of rapid and reproducible exchange of the solution bathing the OHSCs. Measurements of pO2 as a function of tissue depth show that in the region containing the transfected cells, the pO2 is well-controlled. We also found that the pO2 changes on the same time scale as changes in intracranial pressure, cerebral blood flow, and pO2 during acute stroke. Determining the reduction potential, EGSH, from the ratiometric fluorescence signal requires an absolute intensity measurement during calibration of the Grx1-roGFP2. Using the signal from cotransfected tdTomato as an internal standard during calibration improves quantitative measurements of Grx1-roGFP2 redox status and allows EGSH to be determined. EGSH becomes more reducing during OGD and more oxidizing during RP in mitochondria while changes in cytoplasm are not significant compared with controls.
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Affiliation(s)
- Bocheng Yin
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Germán Barrionuevo
- Department
of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Stephen G. Weber
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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29
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Fujisawa Y, Napoli E, Wong S, Song G, Yamaguchi R, Matsui T, Nagasaki K, Ogata T, Giulivi C. Impact of a novel homozygous mutation in nicotinamide nucleotide transhydrogenase on mitochondrial DNA integrity in a case of familial glucocorticoid deficiency. BBA CLINICAL 2015; 3:70-78. [PMID: 26309815 PMCID: PMC4545511 DOI: 10.1016/j.bbacli.2014.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Familial Glucocorticoid Deficiency (FGD) is a rare autosomal recessive disorder that is characterized by isolated glucocorticoid deficiency. Recently, mutations in the gene encoding for the mitochondrial nicotinamide nucleotide transhydrogenase (NNT) have been identified as a causative gene for FGD; however, no NNT activities have been reported in FGD patients carrying NNT mutations. METHODS Clinical, biochemical and molecular analyses of lymphocytes from FDG homozygous and heterozygous carriers for the F215S NNT mutation. RESULTS In this study, we described an FGD-affected Japanese patient carrying a novel NNT homozygous mutation (c.644T>C; F215S) with a significant loss-of-function (NNT activity = 31% of healthy controls) in peripheral blood cells' mitochondria. The NNT activities of the parents, heterozygous for the mutation, were 61% of controls. CONCLUSIONS Our results indicated that (i) mitochondrial biogenesis (citrate synthase activity) and/or mtDNA replication (mtDNA copy number) were affected at ≤60% NNT activity because these parameters were affected in individuals carrying either one or both mutated alleles; and (ii) other outcomes (mtDNA deletions, protein tyrosine nitration, OXPHOS capacity) were affected at ≤30% NNT activity as also observed in murine cerebellar mitochondria from C57BL/6J (NNT-/-) vs. C57BL/6JN (NNT+/+) substrains. GENERAL SIGNIFICANCE By studying a family affected with a novel point mutation in the NNT gene, a gene-dose response was found for various mitochondrial outcomes providing for novel insights into the role of NNT in the maintenance of mtDNA integrity beyond that described for preventing oxidative stress.
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Affiliation(s)
- Yasuko Fujisawa
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
| | - Eleonora Napoli
- Department of Molecular Biosciences, University of California Davis, Davis, CA 95616, USA
| | - Sarah Wong
- Department of Molecular Biosciences, University of California Davis, Davis, CA 95616, USA
| | - Gyu Song
- Department of Molecular Biosciences, University of California Davis, Davis, CA 95616, USA
| | - Rie Yamaguchi
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
| | - Toshiharu Matsui
- Department of Pediatrics, Nagaoka Chuo General Hospital, Nagaoka 940-8653, Japan
| | - Keisuke Nagasaki
- Division of Pediatrics, Niigata University Graduate School of Medicine and Dental Sciences, Niigata 951-8122, Japan
| | - Tsutomu Ogata
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
| | - Cecilia Giulivi
- Department of Molecular Biosciences, University of California Davis, Davis, CA 95616, USA ; Medical Investigations of Neurodevelopmental Disorders (M. I. N. D.) Institute, University of California Davis, Sacramento, CA 95616
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Bouchut A, Chawla AR, Jeffers V, Hudmon A, Sullivan WJ. Proteome-wide lysine acetylation in cortical astrocytes and alterations that occur during infection with brain parasite Toxoplasma gondii. PLoS One 2015; 10:e0117966. [PMID: 25786129 PMCID: PMC4364782 DOI: 10.1371/journal.pone.0117966] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 11/20/2014] [Indexed: 01/22/2023] Open
Abstract
Lysine acetylation is a reversible post-translational modification (PTM) that has been detected on thousands of proteins in nearly all cellular compartments. The role of this widespread PTM has yet to be fully elucidated, but can impact protein localization, interactions, activity, and stability. Here we present the first proteome-wide survey of lysine acetylation in cortical astrocytes, a subtype of glia that is a component of the blood-brain barrier and a key regulator of neuronal function and plasticity. We identified 529 lysine acetylation sites across 304 proteins found in multiple cellular compartments that largely function in RNA processing/transcription, metabolism, chromatin biology, and translation. Two hundred and seventy-seven of the acetylated lysines we identified on 186 proteins have not been reported previously in any other cell type. We also mapped an acetylome of astrocytes infected with the brain parasite, Toxoplasma gondii. It has been shown that infection with T. gondii modulates host cell gene expression, including several lysine acetyltransferase (KAT) and deacetylase (KDAC) genes, suggesting that the host acetylome may also be altered during infection. In the T. gondii-infected astrocytes, we identified 34 proteins exhibiting a level of acetylation >2-fold and 24 with a level of acetylation <2-fold relative to uninfected astrocytes. Our study documents the first acetylome map for cortical astrocytes, uncovers novel lysine acetylation sites, and demonstrates that T. gondii infection produces an altered acetylome.
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Affiliation(s)
- Anne Bouchut
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States of America
| | - Aarti R. Chawla
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States of America
| | - Victoria Jeffers
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States of America
| | - Andy Hudmon
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States of America
| | - William J. Sullivan
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States of America
- Department of Microbiology & Immunology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States of America
- * E-mail:
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Lopert P, Patel M. Nicotinamide nucleotide transhydrogenase (Nnt) links the substrate requirement in brain mitochondria for hydrogen peroxide removal to the thioredoxin/peroxiredoxin (Trx/Prx) system. J Biol Chem 2014; 289:15611-20. [PMID: 24722990 DOI: 10.1074/jbc.m113.533653] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Mitochondrial reactive oxygen species are implicated in the etiology of multiple neurodegenerative diseases, including Parkinson disease. Mitochondria are known to be net producers of ROS, but recently we have shown that brain mitochondria can consume mitochondrial hydrogen peroxide (H2O2) in a respiration-dependent manner predominantly by the thioredoxin/peroxiredoxin system. Here, we sought to determine the mechanism linking mitochondrial respiration with H2O2 catabolism in brain mitochondria and dopaminergic cells. We hypothesized that nicotinamide nucleotide transhydrogenase (Nnt), which utilizes the proton gradient to generate NADPH from NADH and NADP(+), provides the link between mitochondrial respiration and H2O2 detoxification through the thioredoxin/peroxiredoxin system. Pharmacological inhibition of Nnt in isolated brain mitochondria significantly decreased their ability to consume H2O2 in the presence, but not absence, of respiration substrates. Nnt inhibition in liver mitochondria, which do not require substrates to detoxify H2O2, had no effect. Pharmacological inhibition or lentiviral knockdown of Nnt in N27 dopaminergic cells (a) decreased H2O2 catabolism, (b) decreased NADPH and increased NADP(+) levels, and (c) decreased basal, spare, and maximal mitochondrial oxygen consumption rates. Nnt-deficient cells possessed higher levels of oxidized mitochondrial Prx, which rendered them more susceptible to steady-state increases in H2O2 and cell death following exposure to subtoxic levels of paraquat. These data implicate Nnt as the critical link between the metabolic and H2O2 antioxidant function in brain mitochondria and suggests Nnt as a potential therapeutic target to improve the redox balance in conditions of oxidative stress associated with neurodegenerative diseases.
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Affiliation(s)
| | - Manisha Patel
- Department of Pharmaceutical Sciences, The University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
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Venditti P, Di Stefano L, Di Meo S. Mitochondrial metabolism of reactive oxygen species. Mitochondrion 2013; 13:71-82. [DOI: 10.1016/j.mito.2013.01.008] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 01/16/2013] [Accepted: 01/22/2013] [Indexed: 11/16/2022]
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Abstract
Oxidative and nitrosative stress underlie the pathogenesis of a broad range of human diseases, in particular neurodegenerative disorders. Within the brain, neurons are the cells most vulnerable to excess reactive oxygen and nitrogen species; their survival relies on the antioxidant protection promoted by neighbouring astrocytes. However, neurons are also intrinsically equipped with a biochemical mechanism that links glucose metabolism to antioxidant defence. Neurons actively metabolize glucose through the pentose phosphate pathway, which maintains the antioxidant glutathione in its reduced state, hence exerting neuroprotection. This process is tightly controlled by a key glycolysis-promoting enzyme and is dependent on an appropriate supply of energy substrates from astrocytes. Thus brain bioenergetic and antioxidant defence is coupled between neurons and astrocytes. A better understanding of the regulation of this intercellular coupling should be important for identifying novel targets for future therapeutic interventions.
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Yu W, Dittenhafer-Reed KE, Denu JM. SIRT3 protein deacetylates isocitrate dehydrogenase 2 (IDH2) and regulates mitochondrial redox status. J Biol Chem 2012; 287:14078-86. [PMID: 22416140 DOI: 10.1074/jbc.m112.355206] [Citation(s) in RCA: 329] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mitochondria play a central role in oxidative energy metabolism and age-related diseases such as cancer. Accumulation of spurious oxidative damage can cause cellular dysfunction. Antioxidant pathways that rely on NADPH are needed for the reduction of glutathione and maintenance of proper redox status. The mitochondrial matrix protein isocitrate dehydrogenase 2 (IDH2) is a major source of NADPH. Previously, we demonstrated that the NAD(+)-dependent deacetylase SIRT3 was essential for the prevention of age-related hearing loss in mice fed a calorically restricted diet. Here we provide direct biochemical and biological evidence establishing an exquisite regulatory relationship between IDH2 and SIRT3 under acute and chronic caloric restriction. The regulated site of acetylation was mapped to Lys-413, an evolutionarily invariant residue. Site-specific, genetic incorporation of N(ε)-acetyllysine into position 413 of IDH2 revealed that acetylated IDH2 displays a dramatic 44-fold loss in activity. Deacetylation by SIRT3 fully restored maximum IDH2 activity. The ability of SIRT3 to protect cells from oxidative stress was dependent on IDH2, and the deacetylated mimic, IDH2(K413R) variant was able to protect Sirt3(-/-) mouse embryonic fibroblasts from oxidative stress through increased reduced glutathione levels. Together these results uncover a previously unknown mechanism by which SIRT3 regulates IDH2 under dietary restriction. Recent findings demonstrate that IDH2 activities are a major factor in cancer, and as such, these results implicate SIRT3 as a potential regulator of IDH2-dependent functions in cancer cell metabolism.
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Affiliation(s)
- Wei Yu
- Department of Biomolecular Chemistry and the Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, Wisconsin 53715, USA
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The C57BL/6J Mouse Strain Background Modifies the Effect of a Mutation in Bcl2l2. G3-GENES GENOMES GENETICS 2012; 2:99-102. [PMID: 22384386 PMCID: PMC3276190 DOI: 10.1534/g3.111.000778] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 11/09/2011] [Indexed: 11/18/2022]
Abstract
Bcl2l2 encodes BCL-W, an antiapoptotic member of the BCL-2 family of proteins. Intercross of Bcl2l2 +/- mice on a mixed C57BL/6J, 129S5 background produces Bcl2l2 -/- animals with the expected frequency. In contrast, intercross of Bcl2l2 +/- mice on a congenic C57BL/6J background produces relatively few live-born Bcl2l2 -/- animals. Genetic modifiers alter the effect of a mutation. C57BL/6J mice (Mus musculus) have a mutant allele of nicotinamide nucleotide transhydrogenase (Nnt) that can act as a modifier. Loss of NNT decreases the concentration of reduced nicotinamide adenine dinucleotide phosphate within the mitochondrial matrix. Nicotinamide adenine dinucleotide phosphate is a cofactor for glutathione reductase, which regenerates reduced glutathione, an important antioxidant. Thus, loss of NNT activity is associated with increased mitochondrial oxidative damage and cellular stress. To determine whether loss of Bcl2l2 -/- mice on the C57BL/6J background was mediated by the Nnt mutation, we outcrossed Bcl2l2 congenic C57BL/6J (Nnt -/-) mice with the closely related C57BL/6JEiJ (Nnt +/+) strain to produce Bcl2l2 +/- ; Nnt +/+ and Bcl2l2 +/- ; Nnt -/- animals. Intercross of Bcl2l2 +/- ; Nnt +/+ mice produced Bcl2l2 -/- with the expected frequency, whereas intercross of Bcl2l2 +/- ; Nnt -/- animals did not. This finding indicates the C57BL/6J strain background, and possibly the Nnt mutation, modifies the Bcl2l2 mutant phenotype. This and previous reports highlight the importance of knowing the genetic composition of mouse strains used in research studies as well as the accurate reporting of mouse strains in the scientific literature.
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Tretter L, Biagioni Angeli E, Ardestani MR, Goracci G, Adam-Vizi V. Reversible inhibition of hydrogen peroxide elimination by calcium in brain mitochondria. J Neurosci Res 2011; 89:1965-72. [PMID: 21541982 DOI: 10.1002/jnr.22658] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 03/03/2011] [Accepted: 03/14/2011] [Indexed: 11/07/2022]
Abstract
In the present work, the Ca(2+) dependence of mitochondrial H(2) O(2) elimination was investigated. Mitochondria isolated from guinea pig brain were energized by glutamate and malate and incubated with micromolar concentrations of Ca(2+) in the presence of ADP, preventing permeability transition pore formation. After the completion of Ca(2+) uptake, mitochondria were challenged with H(2) O(2) (5 μM), then at various time points residual H(2) O(2) was determined using the Amplex red method and compared with that in mitochondria incubated with H(2) O(2) without Ca(2+) addition. Dose-dependent inhibition of H(2) O(2) elimination by Ca(2+) was detected, which was prevented by the Ca(2+) -uptake inhibitor Ru 360. Stimulation of Ca(2+) release from Ca(2+) -loaded mitochondria by a combined addition of Ru 360 and Na(+) decreased the Ca(2+) -evoked inhibition of H(2) O(2) removal. After Ca(2+) uptake (50 μM), mitochondrial aconitase activity was found to be decreased, which was partially attributable to the impaired elimination of endogenously produced reactive oxygen species. We found that the effects of Ca(2+) and H(2) O(2) on the activity of aconitase were additive. These results confirm that Ca(2+) inhibits elimination of H(2) O(2) in mitochondria and demonstrate that this effect is concentration dependent and reversible. The phenomenon described here can play a role in the modulation of ROS handling under conditions involving excessive cellular Ca(2+) load.
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Affiliation(s)
- Laszlo Tretter
- Department of Medical Biochemistry, Semmelweis University, and Laboratory of Neurobiochemistry and Molecular Physiology, Hungarian Academy of Sciences, Budapest, Hungary
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Glutamate and glutathione interplay in a motor neuronal model of amyotrophic lateral sclerosis reveals altered energy metabolism. Neurobiol Dis 2011; 43:346-55. [PMID: 21530659 DOI: 10.1016/j.nbd.2011.04.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 03/23/2011] [Accepted: 04/07/2011] [Indexed: 12/20/2022] Open
Abstract
Impairment of mitochondrial function might contribute to oxidative stress associated with neurodegeneration in amyotrophic lateral sclerosis (ALS). Glutamate levels in tissues of ALS patients are sometimes altered. In neurons, mitochondrial metabolism of exogenous glutamine is mainly responsible for the net synthesis of glutamate, which is a neurotransmitter, but it is also necessary for the synthesis of glutathione, the main endogenous antioxidant. We investigated glutathione synthesis and glutamine/glutamate metabolism in a motor neuronal model of familial ALS. In standard culture conditions (with glutamine) or restricting glutamine or cystine, the level of glutathione was always lower in the cell line expressing the mutant (G93A) human Cu, Zn superoxide dismutase (G93ASOD1) than in the line expressing wild-type SOD1. With glutamine the difference in glutathione was associated with a lower glutamate and impairment of the glutamine/glutamate metabolism as evidenced by lower glutaminase and cytosolic malate dehydrogenase activity. d-β-hydroxybutyrate, as an alternative to glutamine as energy substrate in addition to glucose, reversed the decreases of cytosolic malate dehydrogenase activity and glutamate and glutathione. However, in the G93ASOD1 cell line, in all culture conditions the expression of pyruvate dehydrogenase kinase l protein, which down-regulates pyruvate dehydrogenase activity, was induced, together with an increase in lactate release in the medium. These findings suggest that the glutathione decrease associated with mutant SOD1 expression is due to mitochondrial dysfunction caused by the reduction of the flow of glucose-derived pyruvate through the TCA cycle; it implies altered glutamate metabolism and depends on the different mitochondrial energy substrates.
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Amaral AI, Teixeira AP, Sonnewald U, Alves PM. Estimation of intracellular fluxes in cerebellar neurons after hypoglycemia: Importance of the pyruvate recycling pathway and glutamine oxidation. J Neurosci Res 2011; 89:700-10. [DOI: 10.1002/jnr.22571] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 11/02/2010] [Accepted: 11/05/2010] [Indexed: 11/06/2022]
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Adam-Vizi V, Starkov AA. Calcium and mitochondrial reactive oxygen species generation: how to read the facts. J Alzheimers Dis 2010; 20 Suppl 2:S413-26. [PMID: 20421693 DOI: 10.3233/jad-2010-100465] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A number of recent discoveries indicate that abnormal Ca2+ signaling, oxidative stress, and mitochondrial dysfunction are involved in the neuronal damage in Alzheimer's disease. However, the literature on the interactions between these factors is controversial especially in the interpretation of the cause-effect relationship between mitochondrial damage induced by Ca2+ overload and the production of reactive oxygen species (ROS). In this review, we survey the experimental observations on the Ca2+-induced mitochondrial ROS production, explain the sources of controversy in interpreting these results, and discuss the different molecular mechanisms underlying the effect of Ca2+ on the ROS emission by brain mitochondria.
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Affiliation(s)
- Vera Adam-Vizi
- Department of Medical Biochemistry, Semmelweis University, Neurobiochemical Group of Hungarian Academy of Sciences, Budapest, Hungary.
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Perez CJ, Jaubert J, Guénet JL, Barnhart KF, Ross-Inta CM, Quintanilla VC, Aubin I, Brandon JL, Otto NW, DiGiovanni J, Gimenez-Conti I, Giulivi C, Kusewitt DF, Conti CJ, Benavides F. Two hypomorphic alleles of mouse Ass1 as a new animal model of citrullinemia type I and other hyperammonemic syndromes. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:1958-68. [PMID: 20724589 DOI: 10.2353/ajpath.2010.100118] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Citrullinemia type I (CTLN1, OMIM# 215700) is an inherited urea cycle disorder that is caused by an argininosuccinate synthetase (ASS) enzyme deficiency. In this report, we describe two spontaneous hypomorphic alleles of the mouse Ass1 gene that serve as an animal model of CTLN1. These two independent mouse mutant alleles, also described in patients affected with CTLN1, interact to produce a range of phenotypes. While some mutant mice died within the first week after birth, others survived but showed severe retardation during postnatal development as well as alopecia, lethargy, and ataxia. Notable pathological findings were similar to findings in human CTLN1 patients and included citrullinemia and hyperammonemia along with delayed cerebellar development, epidermal hyperkeratosis, and follicular dystrophy. Standard treatments for CTLN1 were effective in rescuing the phenotype of these mutant mice. Based on our studies, we propose that defective cerebellar granule cell migration secondary to disorganization of Bergmann glial cell fibers cause cerebellar developmental delay in the hyperammonemic and citrullinemic brain, pointing to a possible role for nitric oxide in these processes. These mouse mutations constitute a suitable model for both mechanistic and preclinical studies of CTLN1 and other hyperammonemic encephalopathies and, at the same time, underscore the importance of complementing knockout mutations with hypomorphic mutations for the generation of animal models of human genetic diseases.
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Affiliation(s)
- Carlos J Perez
- Department of Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, Texas 78957, USA
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Sheeran FL, Rydström J, Shakhparonov MI, Pestov NB, Pepe S. Diminished NADPH transhydrogenase activity and mitochondrial redox regulation in human failing myocardium. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1138-48. [PMID: 20388492 DOI: 10.1016/j.bbabio.2010.04.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 03/30/2010] [Accepted: 04/05/2010] [Indexed: 11/28/2022]
Abstract
Although the functional role of nicotinamide nucleotide transhydrogenase (Nnt) remains to be fully elucidated, there is strong evidence that Nnt plays a critical part in mitochondrial metabolism by maintaining a high NADPH-dependent GSH/GSSG ratio, and thus the control of cellular oxidative stress. Using real-time PCR, spectrophotometric and western blotting techniques, we sought to determine the presence, abundance and activity level of Nnt in human heart tissues and to discern whether these are altered in chronic severe heart failure. Left ventricular levels of the NNT gene and protein expression did not differ significantly between the non-failing donor (NF) and heart failure (HF) group. Notably, compared to NF, Nnt activity rates in the HF group were 18% lower, which coincided with significantly higher levels of oxidized glutathione, lower glutathione reductase activity, lower NADPH and a lower GSH/GSSG ratio. In the failing human heart a partial loss of Nnt activity adversely impacts NADPH-dependent enzymes and the capacity to maintain membrane potential, thus contributing to a decline in bioenergetic capacity, redox regulation and antioxidant defense, exacerbating oxidative damage to cellular proteins.
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Affiliation(s)
- Freya L Sheeran
- Department of Surgery, Monash University Faculty of Medicine, Alfred Hospital, Melbourne, Australia
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Circu ML, Aw TY. Reactive oxygen species, cellular redox systems, and apoptosis. Free Radic Biol Med 2010; 48:749-62. [PMID: 20045723 PMCID: PMC2823977 DOI: 10.1016/j.freeradbiomed.2009.12.022] [Citation(s) in RCA: 2335] [Impact Index Per Article: 166.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 12/21/2009] [Accepted: 12/27/2009] [Indexed: 02/07/2023]
Abstract
Reactive oxygen species (ROS) are products of normal metabolism and xenobiotic exposure, and depending on their concentration, ROS can be beneficial or harmful to cells and tissues. At physiological low levels, ROS function as "redox messengers" in intracellular signaling and regulation, whereas excess ROS induce oxidative modification of cellular macromolecules, inhibit protein function, and promote cell death. Additionally, various redox systems, such as the glutathione, thioredoxin, and pyridine nucleotide redox couples, participate in cell signaling and modulation of cell function, including apoptotic cell death. Cell apoptosis is initiated by extracellular and intracellular signals via two main pathways, the death receptor- and the mitochondria-mediated pathways. Various pathologies can result from oxidative stress-induced apoptotic signaling that is consequent to ROS increases and/or antioxidant decreases, disruption of intracellular redox homeostasis, and irreversible oxidative modifications of lipid, protein, or DNA. In this review, we focus on several key aspects of ROS and redox mechanisms in apoptotic signaling and highlight the gaps in knowledge and potential avenues for further investigation. A full understanding of the redox control of apoptotic initiation and execution could underpin the development of therapeutic interventions targeted at oxidative stress-associated disorders.
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Affiliation(s)
- Magdalena L Circu
- Department of Molecular & Cellular Physiology, Louisiana University Health Sciences Center, Shreveport, LA 71130, USA
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Yap LP, Garcia JV, Han D, Cadenas E. The energy-redox axis in aging and age-related neurodegeneration. Adv Drug Deliv Rev 2009; 61:1283-98. [PMID: 19716388 PMCID: PMC2784280 DOI: 10.1016/j.addr.2009.07.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 07/23/2009] [Indexed: 02/07/2023]
Abstract
Decrease in mitochondrial energy-transducing capacity is a feature of the aging process that accompanies redox alterations, such as increased generation of mitochondrial oxidants, altered GSH status, and increased protein oxidation. The decrease in mitochondrial energy-transducing capacity and altered redox status should be viewed as a concerted process that embodies the mitochondrial energy-redox axis and is linked through various mechanisms including: (a) an inter-convertible reducing equivalents pool (i.e., NAD(P)(+)/NAD(P)H) and (b) redox-mediated protein post-translational modifications involved in energy metabolism. The energy-redox axis provides the rationale for therapeutic approaches targeted to each or both component(s) of the axis that effectively preserves or improve mitochondrial function and that have implications for aging and age-related neurodegenerative disorders.
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Affiliation(s)
- Li-Peng Yap
- Department of Molecular Pharmacology & Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089-9121, USA
| | - Jerome V. Garcia
- Department of Molecular Pharmacology & Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089-9121, USA
- University of LaVerne, Natural Science Division, Department of Biology, 1950 3 Street, LaVerne, CA 91750, USA
| | - Derick Han
- Research Center for Liver Diseases, Keck School of Medicine, University of Southern California, 2011 Zonal Avenue, Los Angeles, CA 90089-9121, USA
| | - Enrique Cadenas
- Department of Molecular Pharmacology & Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089-9121, USA
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Boutros J, Almasan A. Combining 2-deoxy-D-glucose with electron transport chain blockers: a double-edged sword. Cancer Biol Ther 2009; 8:1237-8. [PMID: 19458493 DOI: 10.4161/cbt.8.13.8869] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Jean Boutros
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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Kashem MA, Etages HD, Kopitar-Jerala N, McGregor IS, Matsumoto I. Differential protein expression in the corpus callosum (body) of human alcoholic brain. J Neurochem 2009; 110:486-95. [DOI: 10.1111/j.1471-4159.2009.06141.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Dukhande VV, Isaac AO, Chatterji T, Lai JCK. Reduced glutathione regenerating enzymes undergo developmental decline and sexual dimorphism in the rat cerebral cortex. Brain Res 2009; 1286:19-24. [PMID: 19450567 DOI: 10.1016/j.brainres.2009.05.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 04/30/2009] [Accepted: 05/07/2009] [Indexed: 02/08/2023]
Abstract
Oxidative stress during development may predispose humans to neurodegenerative disorders in old age. Moreover, numerous ailments of brain disproportionately affect one of the genders. We therefore hypothesized that, activities of enzymes regenerating and utilizing glutathione (GSH) show sexual dimorphism and developmental differences in rat brain. To test this hypothesis, we collected cortex tissue from male and female Sprague-Dawley rats at post-natal day (PN) 5, PN 10, PN 20, PN 30, and PN 60. We measured tissue levels of NADP-linked isocitrate dehydrogenase (NADP-ICDH), glucose-6-phosphate dehydrogenase (G6PDH), and, glutathione reductase (GR) by UV spectrophotometry and determined glutathione peroxidase (GPx) expression therein by western blotting. Our results showed that sexual maturation had an impact on activities of enzymes that regenerate and utilize GSH and rat female cortex had more anti-oxidant capacity. Moreover, age-related decline in the activities of these key enzymes were observed. Reduced glutathione and NADPH protects the brain from oxidative stress. Thus, our results may have implications for neurodegenerative disorders like Parkinson's disease and developmental disorders of brain like autism in which oxidative stress plays a key role.
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Affiliation(s)
- Vikas V Dukhande
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Pocatello, ID 83209-8334, USA
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50
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Liu T, O’Rourke B. Regulation of mitochondrial Ca2+ and its effects on energetics and redox balance in normal and failing heart. J Bioenerg Biomembr 2009; 41:127-32. [PMID: 19390955 PMCID: PMC2946065 DOI: 10.1007/s10863-009-9216-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ca(2+) has been well accepted as a signal that coordinates changes in cytosolic workload with mitochondrial energy metabolism in cardiomyocytes. During increased work, Ca(2+) is accumulated in mitochondria and stimulates ATP production to match energy supply and demand. The kinetics of mitochondrial Ca(2+) ([Ca(2+)](m)) uptake remains unclear, and we review the debate on this subject in this article. [Ca(2+)](m) has multiple targets in oxidative phosphorylation including the F1/FO ATPase, the adenine nucleotide translocase, and Ca(2+)-sensitive dehydrogenases (CaDH) of the tricarboxylic acid (TCA) cycle. The well established effect of [Ca(2+)](m) is to activate CaDHs of the TCA cycle to increase NADH production. Maintaining NADH level is not only critical to keep a high oxidative phosphorylation rate during increased cardiac work, but is also necessary for the reducing system of the cell to maintain its reactive oxygen species (ROS) -scavenging capacity. Further, we review recent data demonstrating the deleterious effects of elevated Na(+) in cardiac pathology by blunting [Ca(2+)](m) accumulation.
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Affiliation(s)
- Ting Liu
- Institute of Molecular Cardiobiology, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA
| | - Brian O’Rourke
- Institute of Molecular Cardiobiology, The Johns Hopkins University, 720 Rutland Ave., 1060 Ross Bldg., Baltimore, MD 21205-2195, USA,
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