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Allboani A, Kar S, Kavdia M. Computational modeling of neuronal nitric oxide synthase biochemical pathway: A mechanistic analysis of tetrahydrobiopterin and oxidative stress. Free Radic Biol Med 2024; 222:625-637. [PMID: 39004235 DOI: 10.1016/j.freeradbiomed.2024.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 06/14/2024] [Accepted: 07/11/2024] [Indexed: 07/16/2024]
Abstract
Neuronal cell dysfunction plays an important role in neurodegenerative diseases. Oxidative stress can disrupt the redox balance within neuronal cells and may cause neuronal nitric oxide synthase (nNOS) to uncouple, contributing to the neurodegenerative processes. Experimental studies and clinical trials using nNOS cofactor tetrahydrobiopterin (BH4) and antioxidants in neuronal cell dysfunction have shown inconsistent results. A better mechanistic understanding of complex interactions of nNOS activity and oxidative stress in neuronal cell dysfunction is needed. In this study, we developed a computational model of neuronal cell using nNOS biochemical pathways to explore several key mechanisms that are known to influence neuronal cell redox homeostasis. We studied the effects of oxidative stress and BH4 synthesis on nNOS nitric oxide production and biopterin ratio (BH4/total biopterin). Results showed that nNOS remained coupled and maintained nitric oxide production for oxidative stress levels less than 230 nM/s. The results showed that neuronal oxidative stress above 230 nM/s increased the degree of nNOS uncoupling and introduced instability in the nitric oxide production. The nitric oxide production did not change irrespective of initial biopterin ratio of 0.05-0.99 for a given oxidative stress. Oxidative stress resulted in significant reduction in BH4 levels even when nitric oxide production was not affected. Enhancing BH4 synthesis or supplementation improved nNOS coupling, however the degree of improvement was determined by the levels of oxidative stress and BH4 synthesis. The results of our mechanistic analysis indicate that there is a potential for significant improvement in neuronal dysfunction by simultaneously increasing BH4 levels and reducing cellular oxidative stress.
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Affiliation(s)
- Amnah Allboani
- Department of Biomedical Engineering, Wayne State University, Detroit, MI, 48202, USA
| | - Saptarshi Kar
- College of Engineering and Technology, American University of the Middle East, Kuwait
| | - Mahendra Kavdia
- Department of Biomedical Engineering, Wayne State University, Detroit, MI, 48202, USA.
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2
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Kostyuk AI, Rapota DD, Morozova KI, Fedotova AA, Jappy D, Semyanov AV, Belousov VV, Brazhe NA, Bilan DS. Modern optical approaches in redox biology: Genetically encoded sensors and Raman spectroscopy. Free Radic Biol Med 2024; 217:68-115. [PMID: 38508405 DOI: 10.1016/j.freeradbiomed.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/10/2024] [Accepted: 03/13/2024] [Indexed: 03/22/2024]
Abstract
The objective of the current review is to summarize the current state of optical methods in redox biology. It consists of two parts, the first is dedicated to genetically encoded fluorescent indicators and the second to Raman spectroscopy. In the first part, we provide a detailed classification of the currently available redox biosensors based on their target analytes. We thoroughly discuss the main architecture types of these proteins, the underlying engineering strategies for their development, the biochemical properties of existing tools and their advantages and disadvantages from a practical point of view. Particular attention is paid to fluorescence lifetime imaging microscopy as a possible readout technique, since it is less prone to certain artifacts than traditional intensiometric measurements. In the second part, the characteristic Raman peaks of the most important redox intermediates are listed, and examples of how this knowledge can be implemented in biological studies are given. This part covers such fields as estimation of the redox states and concentrations of Fe-S clusters, cytochromes, other heme-containing proteins, oxidative derivatives of thiols, lipids, and nucleotides. Finally, we touch on the issue of multiparameter imaging, in which biosensors are combined with other visualization methods for simultaneous assessment of several cellular parameters.
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Affiliation(s)
- Alexander I Kostyuk
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Pirogov Russian National Research Medical University, 117997, Moscow, Russia
| | - Diana D Rapota
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Kseniia I Morozova
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Anna A Fedotova
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - David Jappy
- Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow, 117997, Russia
| | - Alexey V Semyanov
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia; Sechenov First Moscow State Medical University, Moscow, 119435, Russia; College of Medicine, Jiaxing University, Jiaxing, Zhejiang Province, 314001, China
| | - Vsevolod V Belousov
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Pirogov Russian National Research Medical University, 117997, Moscow, Russia; Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow, 117997, Russia; Life Improvement by Future Technologies (LIFT) Center, Skolkovo, Moscow, 143025, Russia
| | - Nadezda A Brazhe
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia.
| | - Dmitry S Bilan
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Pirogov Russian National Research Medical University, 117997, Moscow, Russia.
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3
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Gupta DP, Park SH, Lee YS, Lee S, Lim S, Byun J, Cho IH, Song GJ. Daphne genkwa flower extract promotes the neuroprotective effects of microglia. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 108:154486. [PMID: 36240609 DOI: 10.1016/j.phymed.2022.154486] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Microglia are innate immune cells in the central nervous system that play a crucial role in neuroprotection by releasing neurotrophic factors, removing pathogens through phagocytosis, and regulating brain homeostasis. The constituents extracted from the roots and stems of the Daphne genkwa plant have shown neuroprotective effects in an animal model of Parkinson's disease. However, the effect of Daphne genkwa plant extract on microglia has yet to be demonstrated. PURPOSE To study the anti-inflammatory and neuroprotective effects of Daphne genkwa flower extract (GFE) in microglia and explore the underlying mechanisms. METHODS In-vitro mRNA expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase, Arginase1, and brain derived neurotropic factor (BDNF) were analyzed by reverse transcription polymerase chain reaction in microglia cells. Nitric oxide (NO) and TNF-α protein were respectively analyzed by Griess reagent and Enzyme Linked Immunosorbent Assay. Immunoreactivity of Iba-1, Neu-N, and BDNF in mouse brain were analyzed by immunofluorescence staining. Phagocytosis capacity of microglia was examined using fluorescent zymosan-red particles. RESULTS GFE significantly inhibited lipopolysaccharide (LPS)-induced neuroinflammation and promoted neuroprotection both in vitro and in vivo. First, GFE inhibited the LPS-induced inflammatory factors NO, iNOS, and TNF-α in microglial cell lines and primary glial cells, thus demonstrating anti-inflammatory effects. Arginase1 and BDNF mRNA levels were increased in primary glial cells treated with GFE. Phagocytosis was also increased in microglia treated with GFE, suggesting a neuroprotective effect of GFE. In vivo, neuroprotective and anti-neuroinflammatory effects of GFE were also found in the mouse brain, as oral administration of GFE significantly inhibited LPS-induced neuronal loss and inflammatory activation of microglia. CONCLUSION GFE has anti-inflammatory effects and promotes microglial neuroprotective effects. GFE inhibited the pro-inflammatory mediators and enhanced neuroprotective microglia activity by increasing BDNF expression and phagocytosis. These novel findings of the GFE effect on microglia show an innovative approach that can potentially promote neuroprotection for the prevention of neurodegenerative diseases.
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Affiliation(s)
- Deepak Prasad Gupta
- Department of Medical Science, Catholic Kwandong University College of Medicine, Gangneung, Gangwon-do, Korea
| | - Sung Hee Park
- Department of Medical Science, Catholic Kwandong University College of Medicine, Gangneung, Gangwon-do, Korea
| | - Young-Sun Lee
- Department of Medical Science, Catholic Kwandong University College of Medicine, Gangneung, Gangwon-do, Korea; The Convergence Institute of Healthcare and Medical Science, Catholic Kwandong University, International St. Mary's Hospital, Incheon, Korea
| | - Sanghyun Lee
- Department of Plant Science and Technology, Chung-Ang University, Anseong, Korea
| | - Sujin Lim
- Department of Life Science, The Catholic University of Korea, Bucheon, Korea
| | - Jiin Byun
- Department of Life Science, The Catholic University of Korea, Bucheon, Korea
| | - Ik-Hyun Cho
- Department of Convergence Medical Science, College of Korean Medicine, Kyung Hee University, Seoul, Korea.
| | - Gyun Jee Song
- Department of Medical Science, Catholic Kwandong University College of Medicine, Gangneung, Gangwon-do, Korea; The Convergence Institute of Healthcare and Medical Science, Catholic Kwandong University, International St. Mary's Hospital, Incheon, Korea.
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Montali C, Abbruzzetti S, Franzen A, Casini G, Bruno S, Delcanale P, Burgstaller S, Ramadani-Muja J, Malli R, Gensch T, Viappiani C. Nitric Oxide Sensing by a Blue Fluorescent Protein. Antioxidants (Basel) 2022; 11:2229. [PMID: 36421416 PMCID: PMC9686608 DOI: 10.3390/antiox11112229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 09/19/2023] Open
Abstract
S-Nitrosylation of cysteine residues is an important molecular mechanism for dynamic, post-translational regulation of several proteins, providing a ubiquitous redox regulation. Cys residues are present in several fluorescent proteins (FP), including members of the family of Aequorea victoria Green Fluorescent Protein (GFP)-derived FPs, where two highly conserved cysteine residues contribute to a favorable environment for the autocatalytic chromophore formation reaction. The effect of nitric oxide on the fluorescence properties of FPs has not been investigated thus far, despite the tremendous role FPs have played for 25 years as tools in cell biology. We have examined the response to nitric oxide of fluorescence emission by the blue-emitting fluorescent protein mTagBFP2. To our surprise, upon exposure to micromolar concentrations of nitric oxide, we observed a roughly 30% reduction in fluorescence quantum yield and lifetime. Recovery of fluorescence emission is observed after treatment with Na-dithionite. Experiments on related fluorescent proteins from different families show similar nitric oxide sensitivity of their fluorescence. We correlate the effect with S-nitrosylation of Cys residues. Mutation of Cys residues in mTagBFP2 removes its nitric oxide sensitivity. Similarly, fluorescent proteins devoid of Cys residues are insensitive to nitric oxide. We finally show that mTagBFP2 can sense exogenously generated nitric oxide when expressed in a living mammalian cell. We propose mTagBFP2 as the starting point for a new class of genetically encoded nitric oxide sensors based on fluorescence lifetime imaging.
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Affiliation(s)
- Chiara Montali
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7A, 43124 Parma, Italy
| | - Stefania Abbruzzetti
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7A, 43124 Parma, Italy
| | - Arne Franzen
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Giorgia Casini
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Stefano Bruno
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parco Area delle Scienze 23/A, 43124 Parma, Italy
| | - Pietro Delcanale
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7A, 43124 Parma, Italy
| | - Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Jeta Ramadani-Muja
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Thomas Gensch
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Cristiano Viappiani
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7A, 43124 Parma, Italy
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5
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Hirunpattarasilp C, Barkaway A, Davis H, Pfeiffer T, Sethi H, Attwell D. Hyperoxia evokes pericyte-mediated capillary constriction. J Cereb Blood Flow Metab 2022; 42:2032-2047. [PMID: 35786054 PMCID: PMC9580167 DOI: 10.1177/0271678x221111598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Oxygen supplementation is regularly prescribed to patients to treat or prevent hypoxia. However, excess oxygenation can lead to reduced cerebral blood flow (CBF) in healthy subjects and worsen the neurological outcome of critically ill patients. Most studies on the vascular effects of hyperoxia focus on arteries but there is no research on the effects on cerebral capillary pericytes, which are major regulators of CBF. Here, we used bright-field imaging of cerebral capillaries and modeling of CBF to show that hyperoxia (95% superfused O2) led to an increase in intracellular calcium level in pericytes and a significant capillary constriction, sufficient to cause an estimated 25% decrease in CBF. Although hyperoxia is reported to cause vascular smooth muscle cell contraction via generation of reactive oxygen species (ROS), endothelin-1 and 20-HETE, we found that increased cytosolic and mitochondrial ROS levels and endothelin release were not involved in the pericyte-mediated capillary constriction. However, a 20-HETE synthesis blocker greatly reduced the hyperoxia-evoked capillary constriction. Our findings establish pericytes as regulators of CBF in hyperoxia and 20-HETE synthesis as an oxygen sensor in CBF regulation. The results also provide a mechanism by which clinically administered oxygen can lead to a worse neurological outcome.
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Affiliation(s)
- Chanawee Hirunpattarasilp
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Anna Barkaway
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Harvey Davis
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK.,Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Thomas Pfeiffer
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
| | - Huma Sethi
- Division of Neurosurgery, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - David Attwell
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, UK
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6
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Corvace F, Faustmann TJ, Faustmann PM, Ismail FS. Anti-inflammatory properties of lacosamide in an astrocyte-microglia co-culture model of inflammation. Eur J Pharmacol 2022; 915:174696. [PMID: 34902360 DOI: 10.1016/j.ejphar.2021.174696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 11/03/2022]
Abstract
PURPOSE Understanding the effects of antiepileptic drugs on glial cells and glia-mediated inflammation is a new approach to future treatment of epilepsy. Little is known about direct effects of the antiepileptic drug lacosamide (LCM) on glial cells. Therefore, we aimed to study the LCM effects on glial viability, microglial activation, expression of gap-junctional (GJ) protein Cx43 as well as intercellular communication in an in vitro astrocyte-microglia co-culture model of inflammation. METHODS Primary rat astrocytes co-cultures containing 5% (M5, "physiological" conditions) or 30% (M30, "pathological inflammatory" conditions) of microglia were treated with different concentrations of LCM [5, 15, 30, and 90 μg/ml] for 24 h. Glial cell viability was measured by MTT assay. Immunocytochemistry was performed to analyze the microglial activation state. Western blot analysis was used to quantify the astroglial Cx43 expression. The GJ cell communication was studied via Scrape Loading. RESULTS A concentration-dependent incubation with LCM did not affect the glial cell viability both under physiological and pathological conditions. LCM induced a significant concentration-dependent decrease of activated microglia with parallel increase of ramified microglia under pathological inflammatory conditions. This correlated with an increase in astroglial Cx43 expression. Nevertheless, the functional coupling via GJs was significantly reduced after incubation with LCM. CONCLUSION LCM has not shown effects on the glial cell viability. The reduced GJ coupling by LCM could be related to its anti-epileptic activity. The anti-inflammatory glial features of LCM with inhibition of microglial activation under inflammatory conditions support beneficial role in epilepsy associated with neuroinflammation.
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Affiliation(s)
- Franco Corvace
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Bochum, Germany
| | - Timo Jendrik Faustmann
- Department of Psychiatry and Psychotherapy, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Pedro M Faustmann
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Bochum, Germany; International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Fatme Seval Ismail
- Department of Neurology, University Hospital Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany.
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Galler KM, Weber M, Korkmaz Y, Widbiller M, Feuerer M. Inflammatory Response Mechanisms of the Dentine-Pulp Complex and the Periapical Tissues. Int J Mol Sci 2021; 22:ijms22031480. [PMID: 33540711 PMCID: PMC7867227 DOI: 10.3390/ijms22031480] [Citation(s) in RCA: 126] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/25/2021] [Accepted: 01/28/2021] [Indexed: 02/08/2023] Open
Abstract
The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized bone, but also dentine, cementum and enamel of our teeth. These are exposed to intense mechanical and chemical stress as well as to dense microbiologic colonization. Teeth are susceptible to damage, most commonly to caries, where microorganisms from the oral cavity degrade the mineralized tissues of enamel and dentine and invade the soft connective tissue at the core, the dental pulp. However, the pulp is well-equipped to sense and fend off bacteria and their products and mounts various and intricate defense mechanisms. The front rank is formed by a layer of odontoblasts, which line the pulp chamber towards the dentine. These highly specialized cells not only form mineralized tissue but exert important functions as barrier cells. They recognize pathogens early in the process, secrete antibacterial compounds and neutralize bacterial toxins, initiate the immune response and alert other key players of the host defense. As bacteria get closer to the pulp, additional cell types of the pulp, including fibroblasts, stem and immune cells, but also vascular and neuronal networks, contribute with a variety of distinct defense mechanisms, and inflammatory response mechanisms are critical for tissue homeostasis. Still, without therapeutic intervention, a deep carious lesion may lead to tissue necrosis, which allows bacteria to populate the root canal system and invade the periradicular bone via the apical foramen at the root tip. The periodontal tissues and alveolar bone react to the insult with an inflammatory response, most commonly by the formation of an apical granuloma. Healing can occur after pathogen removal, which is achieved by disinfection and obturation of the pulp space by root canal treatment. This review highlights the various mechanisms of pathogen recognition and defense of dental pulp cells and periradicular tissues, explains the different cell types involved in the immune response and discusses the mechanisms of healing and repair, pointing out the close links between inflammation and regeneration as well as between inflammation and potential malignant transformation.
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Affiliation(s)
- Kerstin M. Galler
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, 93093 Regensburg, Germany;
- Correspondence:
| | - Manuel Weber
- Department of Oral and Maxillofacial Surgery, Friedrich-Alexander University Erlangen-Nürnberg, 91054 Erlangen, Germany;
| | - Yüksel Korkmaz
- Department of Periodontology and Operative Dentistry, University of Mainz, 55131 Mainz, Germany;
| | - Matthias Widbiller
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, 93093 Regensburg, Germany;
| | - Markus Feuerer
- Department for Immunology, University Hospital Regensburg, 93053 Regensburg, Germany;
- Regensburg Center for Interventional Immunology (RCI), University Hospital Regensburg, 93053 Regensburg, Germany
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8
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Ahuja BB, Vigalok A. Fluorescent Calixarene Scaffolds for NO Detection in Protic Media. Angew Chem Int Ed Engl 2019; 58:2774-2778. [DOI: 10.1002/anie.201813589] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/16/2019] [Indexed: 01/07/2023]
Affiliation(s)
- Brij Bhushan Ahuja
- School of ChemistryThe Sackler Faculty of Exact SciencesTel Aviv University Tel Aviv 69978 Israel
| | - Arkadi Vigalok
- School of ChemistryThe Sackler Faculty of Exact SciencesTel Aviv University Tel Aviv 69978 Israel
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9
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Ahuja BB, Vigalok A. Fluorescent Calixarene Scaffolds for NO Detection in Protic Media. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813589] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Brij Bhushan Ahuja
- School of ChemistryThe Sackler Faculty of Exact SciencesTel Aviv University Tel Aviv 69978 Israel
| | - Arkadi Vigalok
- School of ChemistryThe Sackler Faculty of Exact SciencesTel Aviv University Tel Aviv 69978 Israel
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10
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Engl E, Jolivet R, Hall CN, Attwell D. Non-signalling energy use in the developing rat brain. J Cereb Blood Flow Metab 2017; 37:951-966. [PMID: 27170699 PMCID: PMC5322833 DOI: 10.1177/0271678x16648710] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/30/2016] [Accepted: 04/05/2016] [Indexed: 11/26/2022]
Abstract
Energy use in the brain constrains its information processing power, but only about half the brain's energy consumption is directly related to information processing. Evidence for which non-signalling processes consume the rest of the brain's energy has been scarce. For the first time, we investigated the energy use of the brain's main non-signalling tasks with a single method. After blocking each non-signalling process, we measured oxygen level changes in juvenile rat brain slices with an oxygen-sensing microelectrode and calculated changes in oxygen consumption throughout the slice using a modified diffusion equation. We found that the turnover of the actin and microtubule cytoskeleton, followed by lipid synthesis, are significant energy drains, contributing 25%, 22% and 18%, respectively, to the rate of oxygen consumption. In contrast, protein synthesis is energetically inexpensive. We assess how these estimates of energy expenditure relate to brain energy use in vivo, and how they might differ in the mature brain.
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Affiliation(s)
- Elisabeth Engl
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Renaud Jolivet
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
- CERN, and Département de physique nucléaire et corpusculaire (DPNC), University of Geneva, Geneva, Switzerland
| | | | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
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11
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Terraneo L, Bianciardi P, Malavalli A, Mkrtchyan G, Spann SN, Lohman J, Samaja M, Vandegriff KD. Hemoglobin extravasation in the brain of rats exchange-transfused with hemoglobin-based oxygen carriers. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2016; 45:710-716. [PMID: 27908199 DOI: 10.1080/21691401.2016.1263640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Haemoglobin (Hb)-based oxygen carriers are under consideration as oxygen therapeutics. Their effect on apoptosis is critical, because the onset of pro-apoptotic pathways may lead to tissue damage. MP4OX, a polyethylene glycol-conjugated human Hb preserves the baseline level of neuron apoptosis with respect to sham. Here we develop a method for measuring Hb extravasation in brain. We exchange transfused rats by haemorrhaging 50% of their blood with simultaneous, isovolemic replacement with Hextend (negative control), MP4OX, or αα-cross-linked Hb. Animals were sacrificed 2 h after transfusion, brain tissue was harvested and processed for double-staining immunofluorescence, whereby Hb ? chain and NeuN (a neuron protein) were stained and quantitated. Whereas Hextend did not induce Hb extravasation, in both MP4OX and ??Hb brains Hb molecules were detected outside neurons. The level of extravasated Hb chains was > 3-fold higher in Hb compared to MP4OX. Western blot analysis revealed that the expression levels of protein related to redox imbalance (e.g., Nrf2, iNOS and ERK phosphorylation) were higher in ααHb than MP4OX. In conclusions, higher Hb extravasation in ααHb than MP4OX induces redox imbalance, which causes higher anti-oxidant response. Whereas Nrf2 response may be considered protective, iNOS response appears damaging.
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Affiliation(s)
- Laura Terraneo
- a Department of Health Science , University of Milan , Milan , Italy
| | - Paola Bianciardi
- a Department of Health Science , University of Milan , Milan , Italy
| | - Ashok Malavalli
- b NovoSang, Inc. , San Diego , CA , USA.,c Sangart Inc. , San Diego , CA , USA
| | | | | | | | - Michele Samaja
- a Department of Health Science , University of Milan , Milan , Italy
| | - Kim D Vandegriff
- b NovoSang, Inc. , San Diego , CA , USA.,c Sangart Inc. , San Diego , CA , USA
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12
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Kann O, Hollnagel JO, Elzoheiry S, Schneider J. Energy and Potassium Ion Homeostasis during Gamma Oscillations. Front Mol Neurosci 2016; 9:47. [PMID: 27378847 PMCID: PMC4909733 DOI: 10.3389/fnmol.2016.00047] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/30/2016] [Indexed: 12/21/2022] Open
Abstract
Fast neuronal network oscillations in the gamma frequency band (30-100 Hz) occur in various cortex regions, require timed synaptic excitation and inhibition with glutamate and GABA, respectively, and are associated with higher brain functions such as sensory perception, attentional selection and memory formation. However, little is known about energy and ion homeostasis during the gamma oscillation. Recent studies addressed this topic in slices of the rodent hippocampus using cholinergic and glutamatergic receptor models of gamma oscillations (GAM). Methods with high spatial and temporal resolution were applied in vitro, such as electrophysiological recordings of local field potential (LFP) and extracellular potassium concentration ([K(+)]o), live-cell fluorescence imaging of nicotinamide adenine dinucleotide (phosphate) and flavin adenine dinucleotide [NAD(P)H and FAD, respectively] (cellular redox state), and monitoring of the interstitial partial oxygen pressure (pO2) in depth profiles with microsensor electrodes, including mathematical modeling. The main findings are: (i) GAM are associated with high oxygen consumption rate and significant changes in the cellular redox state, indicating rapid adaptations in glycolysis and oxidative phosphorylation; (ii) GAM are accompanied by fluctuating elevations in [K(+)]o of less than 0.5 mmol/L from baseline, likely reflecting effective K(+)-uptake mechanisms of neuron and astrocyte compartments; and (iii) GAM are exquisitely sensitive to metabolic stress induced by lowering oxygen availability or by pharmacological inhibition of the mitochondrial respiratory chain. These findings reflect precise cellular adaptations to maintain adenosine-5'-triphosphate (ATP), ion and neurotransmitter homeostasis and thus neural excitability and synaptic signaling during GAM. Conversely, the exquisite sensitivity of GAM to metabolic stress might significantly contribute the exceptional vulnerability of higher brain functions in brain disease.
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Affiliation(s)
- Oliver Kann
- Institute of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of HeidelbergHeidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of HeidelbergHeidelberg, Germany
| | - Shehabeldin Elzoheiry
- Institute of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of HeidelbergHeidelberg, Germany
| | - Justus Schneider
- Institute of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of HeidelbergHeidelberg, Germany
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Tarasenko AS. THE EFFECT OF NITRIC OXIDE ON SYNAPTIC VESICLE PROTON GRADIENT AND MITOCHONDRIAL POTENTIAL OF BRAIN NERVE TERMINALS. UKRAINIAN BIOCHEMICAL JOURNAL 2016; 87:64-75. [PMID: 27025060 DOI: 10.15407/ubj87.06.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The effect of nitric oxide on synaptic vesicle proton gradient and membrane potential of rat brain nerve terminals was studied. It has been shown that nitric oxide in the form of S-nitrosothiols at nanomolar concentrations had no effect on the studied parameters, but caused a rapid dissipation of synaptic vesicle proton gradient and depolarization of mitochondrial membrane in the presence of a SH-reducing compound such as dithiothreitol. Both processes were reversible and the rate of H(+)-gradient restoration depended on the redox potential of nerve terminals, namely the molar ratio of reductant/oxidant. This facts, as well as insensitivity of the studied processes to the inhibitor of NO-sensitive guanylate cyclase such as ODQ, allow suggesting that post-translational modification of thiol residues of the mitochondrial and synaptic vesicle proteins underlies the effect of nitric oxide on the key functional parameters ofpresynaptic nerve terminals.
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Goud PT, Goud AP, Najafi T, Gonik B, Diamond MP, Saed GM, Zhang X, Abu-Soud HM. Direct real-time measurement of intra-oocyte nitric oxide concentration in vivo. PLoS One 2014; 9:e98720. [PMID: 24887331 PMCID: PMC4041775 DOI: 10.1371/journal.pone.0098720] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 05/06/2014] [Indexed: 11/18/2022] Open
Abstract
Nitric oxide (NO) is reported to play significant a role in oocyte activation and maturation, implantation, and early embryonic development. Previously we have shown that NO forms an important component of the oocyte microenvironment, and functions effectively to delay oocyte aging. Thus, precise information about intra-oocyte NO concentrations [NO] will result in designing more accurate treatment plans in assisted reproduction. In this work, the direct, real-time and quantitative intra-oocyte [NO] was measured utilizing an L-shaped amperometric integrated NO-selective electrode. This method not only provides an elegant and convenient approach to real-time the measurement of NO in physiological environments, but also mimics the loss of NO caused by rapid NO diffusion combined with its reactivity in the biological milieu. This experiment suggests that the NO levels of oocytes obtained from young animals are significantly higher than those of oocytes obtained from old animals. Additionally the NO levels stay constant during the measurements; however, the intra-oocyte [NO] is reduced significantly (70-75% reduction) in response to L-NAME incubation, suggesting that NO measurements are truly NOS based rather than caused by an unknown interfering substance in our system. We believe this first demonstration of the direct quantitative measurement of [NO] in situ in an intact cellular complex should be useful in tracking real-time and rapid changes at nanomolar levels. Moreover, this finding confirms and extends our previous work showing that supplementation with NO delays the oocyte aging process.
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Affiliation(s)
- Pravin T. Goud
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of California Davis, Sacramento, California, United States of America
- California IVF Fertility Center, Davis and Sacramento, California, United States of America
| | - Anuradha P. Goud
- California National Primate Research Center, University California Davis, Davis, California, United States of America
| | - Tohid Najafi
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America
| | - Bernard Gonik
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America
| | - Michael P. Diamond
- Department of Obstetrics & Gynecology, Georgia Regents University, Augusta, Georgia, United States of America
| | - Ghassan M. Saed
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America
| | - Xueji Zhang
- World Precision Instruments, Sarasota, Florida, United States of America
- Research Center for Bioengineering & Sensing Technology, University of Science & Technology, Beijing, P.R. China
| | - Husam M. Abu-Soud
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, The C. S. Mott Center for Human Growth and Development, Wayne State University, Detroit, Michigan, United States of America
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States of America
- * E-mail:
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15
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Hall CN, Reynell C, Gesslein B, Hamilton NB, Mishra A, Sutherland BA, O'Farrell FM, Buchan AM, Lauritzen M, Attwell D. Capillary pericytes regulate cerebral blood flow in health and disease. Nature 2014; 508:55-60. [PMID: 24670647 PMCID: PMC3976267 DOI: 10.1038/nature13165] [Citation(s) in RCA: 1253] [Impact Index Per Article: 125.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 02/19/2014] [Indexed: 01/12/2023]
Abstract
Increases in brain blood flow, evoked by neuronal activity, power neural computation and form the basis of BOLD (blood-oxygen-level-dependent) functional imaging. Whether blood flow is controlled solely by arteriole smooth muscle, or also by capillary pericytes, is controversial. We demonstrate that neuronal activity and the neurotransmitter glutamate evoke the release of messengers that dilate capillaries by actively relaxing pericytes. Dilation is mediated by prostaglandin E2, but requires nitric oxide release to suppress vasoconstricting 20-HETE synthesis. In vivo, when sensory input increases blood flow, capillaries dilate before arterioles and are estimated to produce 84% of the blood flow increase. In pathology, ischaemia evokes capillary constriction by pericytes. We show that this is followed by pericyte death in rigor, which may irreversibly constrict capillaries and damage the blood-brain barrier. Thus, pericytes are major regulators of cerebral blood flow and initiators of functional imaging signals. Prevention of pericyte constriction and death may reduce the long-lasting blood flow decrease that damages neurons after stroke.
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Affiliation(s)
- Catherine N Hall
- Department of Neuroscience, Physiology & Pharmacology University College London, Gower St., London, WC1E 6BT, UK
| | - Clare Reynell
- Department of Neuroscience, Physiology & Pharmacology University College London, Gower St., London, WC1E 6BT, UK
| | - Bodil Gesslein
- Department of Neuroscience & Pharmacology and Center for Healthy Aging, and Department of Clinical Neurophysiology, Glostrup Hospital, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Nicola B Hamilton
- Department of Neuroscience, Physiology & Pharmacology University College London, Gower St., London, WC1E 6BT, UK
| | - Anusha Mishra
- Department of Neuroscience, Physiology & Pharmacology University College London, Gower St., London, WC1E 6BT, UK
| | - Brad A Sutherland
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
| | - Fergus M O'Farrell
- Department of Neuroscience, Physiology & Pharmacology University College London, Gower St., London, WC1E 6BT, UK
| | - Alastair M Buchan
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
| | - Martin Lauritzen
- Department of Neuroscience & Pharmacology and Center for Healthy Aging, and Department of Clinical Neurophysiology, Glostrup Hospital, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology University College London, Gower St., London, WC1E 6BT, UK
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16
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Abstract
Endothelial nitric oxide (NO) is generated by constitutively active endothelial nitric oxide synthase (eNOS), an essential enzyme responsible for cardiovascular homeostasis. Historically, endothelial NO was first recognized as a major vasodilator involved in control of vasomotor function and local blood flow. In this review, our attention is focused on the emerging role of endothelial NO in linking cerebrovascular function with cognition. We will discuss the recognized ability of endothelial NO to modulate processing of amyloid precursor protein (APP), influence functional status of microglia, and affect cognitive function. Existing evidence suggests that the loss of NO in cultured human cerebrovascular endothelium causes increased expression of APP and β-site APP-cleaving enzyme 1 (BACE1) thereby resulting in increased secretion of amyloid β peptides (Aβ1-40 and Aβ1-42). Furthermore, increased expression of APP and BACE1 as well as increased production of Aβ peptides was detected in the cerebral microvasculature and brain tissue of eNOS-deficient mice. Since Aβ peptides are considered major cytotoxic molecules responsible for the pathogenesis of Alzheimer's disease, these observations support the concept that a loss of endothelial NO might significantly contribute to the initiation and progression of cognitive decline. In addition, genetic inactivation of eNOS causes activation of microglia and promotes a pro-inflammatory phenotype in the brain. Behavioural analysis revealed that eNOS-deficient mice exhibit impaired cognitive performance thereby indicating that selective loss of endothelial NO has a detrimental effect on the function of neuronal cells. Together with findings from prior studies demonstrating the ability of endothelial NO to affect synaptic plasticity, mitochondrial biogenesis, and function of neuronal progenitor cells, it is becoming apparent that the role of endothelial NO in the control of central nervous system function is very complex. We propose that endothelial NO represents the key molecule linking cerebrovascular and neuronal function.
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Affiliation(s)
- Zvonimir S Katusic
- Department of Anesthesiology, Vascular Biology Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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17
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Arafa MH, Atteia HH. Sildenafil citrate attenuates the deleterious effects of elevated ammonia. Toxicol Mech Methods 2013; 23:402-11. [DOI: 10.3109/15376516.2013.770109] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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18
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Oxidative phosphorylation, not glycolysis, powers presynaptic and postsynaptic mechanisms underlying brain information processing. J Neurosci 2012; 32:8940-51. [PMID: 22745494 DOI: 10.1523/jneurosci.0026-12.2012] [Citation(s) in RCA: 298] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Neural activity has been suggested to initially trigger ATP production by glycolysis, rather than oxidative phosphorylation, for three reasons: glycolytic enzymes are associated with ion pumps; neurons may increase their energy supply by activating glycolysis in astrocytes to generate lactate; and activity increases glucose uptake more than O₂ uptake. In rat hippocampal slices, neuronal activity rapidly decreased the levels of extracellular O₂ and intracellular NADH (reduced nicotinamide adenine dinucleotide), even with lactate dehydrogenase blocked to prevent lactate generation, or with only 20% superfused O₂ to mimic physiological O₂ levels. Pharmacological analysis revealed an energy budget in which 11% of O₂ use was on presynaptic action potentials, 17% was on presynaptic Ca²⁺ entry and transmitter release, 46% was on postsynaptic glutamate receptors, and 26% was on postsynaptic action potentials, in approximate accord with theoretical brain energy budgets. Thus, the major mechanisms mediating brain information processing are all initially powered by oxidative phosphorylation, and an astrocyte-neuron lactate shuttle is not needed for this to occur.
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19
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Agathocleous M, Love NK, Randlett O, Harris JJ, Liu J, Murray AJ, Harris WA. Metabolic differentiation in the embryonic retina. Nat Cell Biol 2012; 14:859-64. [PMID: 22750943 PMCID: PMC3442239 DOI: 10.1038/ncb2531] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 05/24/2012] [Indexed: 12/21/2022]
Abstract
Unlike healthy adult tissues, cancers produce energy mainly by aerobic glycolysis instead of oxidative phosphorylation. This adaptation, called the Warburg effect, may be a feature of all dividing cells, both normal and cancerous, or it may be specific to cancers. It is not known whether, in a normally growing tissue during development, proliferating and postmitotic cells produce energy in fundamentally different ways. Here we show in the embryonic Xenopus retina in vivo, that dividing progenitor cells depend less on oxidative phosphorylation for ATP production than non-dividing differentiated cells, and instead use glycogen to fuel aerobic glycolysis. The transition from glycolysis to oxidative phosphorylation is connected to the cell differentiation process. Glycolysis is indispensable for progenitor proliferation and biosynthesis, even when it is not used for ATP production. These results suggest that the Warburg effect can be a feature of normal proliferation in vivo, and that the regulation of glycolysis and oxidative phosphorylation is critical for normal development.
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Affiliation(s)
- Michalis Agathocleous
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom
- Gonville and Caius College, Cambridge CB2 1TA, United Kingdom
| | - Nicola K. Love
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom
| | - Owen Randlett
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom
| | - Julia J. Harris
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, United Kingdom
| | - Jinyue Liu
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom
| | - Andrew J. Murray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom
| | - William A. Harris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, United Kingdom
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20
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Laranjinha J, Santos RM, Lourenço CF, Ledo A, Barbosa RM. Nitric oxide signaling in the brain: translation of dynamics into respiration control and neurovascular coupling. Ann N Y Acad Sci 2012; 1259:10-8. [DOI: 10.1111/j.1749-6632.2012.06582.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Nitric oxide inactivation mechanisms in the brain: role in bioenergetics and neurodegeneration. Int J Cell Biol 2012; 2012:391914. [PMID: 22719764 PMCID: PMC3376480 DOI: 10.1155/2012/391914] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 04/18/2012] [Indexed: 10/28/2022] Open
Abstract
During the last decades nitric oxide ((•)NO) has emerged as a critical physiological signaling molecule in mammalian tissues, notably in the brain. (•)NO may modify the activity of regulatory proteins via direct reaction with the heme moiety, or indirectly, via S-nitrosylation of thiol groups or nitration of tyrosine residues. However, a conceptual understanding of how (•)NO bioactivity is carried out in biological systems is hampered by the lack of knowledge on its dynamics in vivo. Key questions still lacking concrete and definitive answers include those related with quantitative issues of its concentration dynamics and diffusion, summarized in the how much, how long, and how far trilogy. For instance, a major problem is the lack of knowledge of what constitutes a physiological (•)NO concentration and what constitutes a pathological one and how is (•)NO concentration regulated. The ambient (•)NO concentration reflects the balance between the rate of synthesis and the rate of breakdown. Much has been learnt about the mechanism of (•)NO synthesis, but the inactivation pathways of (•)NO has been almost completely ignored. We have recently addressed these issues in vivo on basis of microelectrode technology that allows a fine-tuned spatial and temporal measurement (•)NO concentration dynamics in the brain.
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22
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Fayed AHA, Gad SB. Effect of sildenafil citrate (Viagra®) on trace element concentration in serum and brain of rats. J Trace Elem Med Biol 2011; 25:236-8. [PMID: 22036616 DOI: 10.1016/j.jtemb.2011.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 08/24/2011] [Accepted: 09/30/2011] [Indexed: 11/28/2022]
Abstract
As a vasodilator with good hemodynamic effects, sildenafil has been successfully used in the treatment of patients with pulmonary hypertension and cardiovascular diseases. By selectively inhibiting phosphodiestrase type 5 (PDE-5) and thus effectively reducing the breakdown of c GMP, sildenafil administration can markedly improve the erectile dysfunction. Sildenafil also elevates localized cerebral blood flow in rat brain. The objective of the present study was to investigate the effect of sildenafil on the level of trace elements (Zinc (Zn), copper (Cu), iron (Fe), selenium (Se), cobalt (Co), and chromium (Cr)) in blood and brain of rats. Sixteen male albino rats weighing 180-200 g were divided into two groups (8 rats/group). Sildenafil (Viagra, Pfizer Inc.) was dissolved in saline and administered at a dose of 10mg/kg i.p. (0.5 ml volume) to rats in the treated group every 72 h for 12 injections. Rats in the control group were administered the same volume of saline as in treated group. All rats were sacrificed 24h after the last injection. Blood samples were collected and serum was separated and stored at -20°C. Brains were dissected and stored frozen until analysis. Trace elements concentrations were determined by flame emission atomic absorption spectrophotometer. Results showed that sildenafil injection significantly (P<0.05) increased serum and brain Se and Cu concentrations. Moreover, sildenafil increased the Cr concentration in the brain tissue. It was concluded that sildenafil citrate administration increased serum Se and Cu as well as, increased brain Se, Cu, and Cr concentrations in rats.
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Affiliation(s)
- Abdel-Hasseb A Fayed
- Department of Physiology, Faculty of Veterinary Medicine, Alexandria University, Edfina, Egypt.
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23
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Doucet MV, Harkin A, Dev KK. The PSD-95/nNOS complex: new drugs for depression? Pharmacol Ther 2011; 133:218-29. [PMID: 22133842 DOI: 10.1016/j.pharmthera.2011.11.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 11/02/2011] [Indexed: 12/11/2022]
Abstract
Drug treatment of major depressive disorder is currently limited to the use of agents which influence monoaminergic neuronal transmission including inhibitors of presynaptic transporters and monoamine oxidase. Typically improvement in depressive symptoms only emerges after several weeks of treatment, suggesting that downstream neuronal adaptations rather than the elevation in synaptic monoamine levels are responsible for antidepressant effects. In recent years, the NMDA receptor has emerged as a promising target for treating CNS disorders including stroke, pain and depression. In this review, we outline the molecular mechanisms underlying NMDA receptor signalling in neurons and in particular provide an overview of the role of the NMDAR/PSD-95/nNOS complex in CNS disorders. We discuss novel drug developments made that suggest the NMDAR/PSD-95/nNOS complex as a potential target for the treatment of depression. The review also provides examples of how PDZ-based protein-protein interactions can be exploited as novel drug targets for disease.
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Affiliation(s)
- Marika V Doucet
- Molecular Neuropharmacology, Department of Physiology, Trinity College, Dublin 2, Ireland
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24
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Wood KC, Batchelor AM, Bartus K, Harris KL, Garthwaite G, Vernon J, Garthwaite J. Picomolar nitric oxide signals from central neurons recorded using ultrasensitive detector cells. J Biol Chem 2011; 286:43172-81. [PMID: 22016390 PMCID: PMC3234811 DOI: 10.1074/jbc.m111.289777] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Nitric oxide (NO) is a widespread signaling molecule with potentially multifarious actions of relevance to health and disease. A fundamental determinant of how it acts is its concentration, but there remains a lack of coherent information on the patterns of NO release from its sources, such as neurons or endothelial cells, in either normal or pathological conditions. We have used detector cells having the highest recorded NO sensitivity to monitor NO release from brain tissue quantitatively and in real time. Stimulation of NMDA receptors, which are coupled to activation of neuronal NO synthase, routinely generated NO signals from neurons in cerebellar slices. The average computed peak NO concentrations varied across the anatomical layers of the cerebellum, from 12 to 130 pm. The mean value found in the hippocampus was 200 pm. Much variation in the amplitudes recorded by individual detector cells was observed, this being attributable to their location at variable distances from the NO sources. From fits to the data, the NO concentrations at the source surfaces were 120 pm to 1.4 nm, and the underlying rates of NO generation were 36–350 nm/s, depending on area. Our measurements are 4–5 orders of magnitude lower than reported by some electrode recordings in cerebellum or hippocampus. In return, they establish coherence between the NO concentrations able to elicit physiological responses in target cells through guanylyl cyclase-linked NO receptors, the concentrations that neuronal NO synthase is predicted to generate locally, and the concentrations that neurons actually produce.
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Affiliation(s)
- Katherine C Wood
- Wolfson Institute for Biomedical Research, University College London, London WCIE 6BT, United Kingdom
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25
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Lewandowska H, Kalinowska M, Brzóska K, Wójciuk K, Wójciuk G, Kruszewski M. Nitrosyl iron complexes--synthesis, structure and biology. Dalton Trans 2011; 40:8273-89. [PMID: 21643591 DOI: 10.1039/c0dt01244k] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nitrosyl complexes of iron are formed in living species in the presence of nitric oxide. They are considered a form in which NO can be stored and stabilized within a living cell. Upon entering a topic in bioinorganic chemistry the researcher faces a wide spectrum of issues concerning synthetic methods, the structure and chemical properties of the complex on the one hand, and its biological implications on the other. The aim of this review is to present the newest knowledge on nitrosyl iron complexes, summarizing the issues that are important for understanding the nature of nitrosyl iron complexes, their possible interactions, behavior in vitro and in vivo, handling of the preparations etc. in response to the growing interest in these compounds. Herein we focus mostly on the dinitrosyl iron complexes (DNICs) due to their prevailing occurrence in NO-treated biological samples. This article reviews recent knowledge on the structure, chemical properties and biological action of DNICs and some mononitrosyls of heme proteins. Synthetic methods are also briefly reviewed.
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Affiliation(s)
- Hanna Lewandowska
- Institute of Nuclear Chemistry and Technology, Centre for Radiobiology and Biological Dosimetry, 16 Dorodna Str., 03-195, Warsaw, Poland
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26
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Santos RM, Lourenço CF, Pomerleau F, Huettl P, Gerhardt GA, Laranjinha J, Barbosa RM. Brain nitric oxide inactivation is governed by the vasculature. Antioxid Redox Signal 2011; 14:1011-21. [PMID: 20712398 DOI: 10.1089/ars.2010.3297] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The mechanisms underlying nitric oxide ((•)NO) synthesis and inactivation in the brain are essential determinants of (•)NO neuroactivity. Although (•)NO production is well characterized, the pathways of inactivation in vivo remain largely unknown. Here, we characterize the kinetics and the major mechanism of (•)NO inactivation in the rat brain cortex and hippocampus in vivo by measuring locally applied (•)NO with carbon-fiber microelectrodes (CFMs) and ceramic-based microelectrode arrays (MEAs). An apparent first-order clearance was observed in both brain regions, with decay rate constants (k) of (•)NO signals of 0.67 to 0.84 per second, significantly higher than the k obtained in agarose gel (0.099 per second), used as a (•)NO diffusion-control medium. (•)NO half-life in vivo, estimated by mathematical modeling, was 0.42 to 0.75 s. Experiments using MEAs support that the (•)NO diffusion radius is heterogeneous and related to local metabolic activity and vascular density. After global ischemia, k decreased to control values of diffusion in gel, but during anoxia, k decreased only 21%. Additionally, k in brain slices was threefold to fivefold lower than that in vivo, and hemorrhagic shock induced a 53% decrease in k. Overall, the results support that (•)NO scavenging by circulating erythrocytes constitutes the major (•)NO-inactivation pathway in the brain.
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Affiliation(s)
- Ricardo M Santos
- Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, Coimbra, Portugal
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27
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Ong PK, Jain S, Kim S. Temporal variations of the cell-free layer width may enhance NO bioavailability in small arterioles: Effects of erythrocyte aggregation. Microvasc Res 2011; 81:303-12. [PMID: 21345341 DOI: 10.1016/j.mvr.2011.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 02/11/2011] [Accepted: 02/12/2011] [Indexed: 11/29/2022]
Abstract
Recently, we have shown that temporal variations in the cell-free layer width can potentially enhance nitric oxide (NO) bioavailability in small arterioles. Since the layer width variations can be augmented by red blood cell aggregation, we tested the hypothesis that an increase in the layer width variations due to red blood cell aggregation could provide an underlying mechanism to improve NO bioavailability in the endothelium and promote vasodilatory effects. Utilizing cell-free layer width data acquired from arterioles of the rat cremaster muscle before and after dextran infusion in reduced flow conditions (wall shear stress=0.13-0.24Pa), our computational model predicted exponential enhancements of NO bioavailability in the endothelium and soluble guanylyl cyclase (sGC) activation in the smooth muscle layer with increasing temporal variability of the layer width. These effects were mediated primarily by the transient responses of wall shear stress and NO production rate to the layer width variations. The temporal variations in the layer width were significantly enhanced (P<0.05) by aggregation, leading to significant improvements (P<0.05) in NO bioavailability and sGC activation. As a result, the significant reduction (P<0.05) of sGC activation due to the increased width of the layer after aggregation induction was diminished by the opposing effect of the layer variations. These findings highlighted the possible enhancement of NO bioavailability and vascular tone in the arteriole by the augmented layer width variations due to the aggregation.
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Affiliation(s)
- Peng Kai Ong
- Division of Bioengineering & Department of Surgery, National University of Singapore, Singapore
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Attwell D, Buchan AM, Charpak S, Lauritzen M, Macvicar BA, Newman EA. Glial and neuronal control of brain blood flow. Nature 2010; 468:232-43. [PMID: 21068832 PMCID: PMC3206737 DOI: 10.1038/nature09613] [Citation(s) in RCA: 1650] [Impact Index Per Article: 117.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Blood flow in the brain is regulated by neurons and astrocytes. Knowledge of how these cells control blood flow is crucial for understanding how neural computation is powered, for interpreting functional imaging scans of brains, and for developing treatments for neurological disorders. It is now recognized that neurotransmitter-mediated signalling has a key role in regulating cerebral blood flow, that much of this control is mediated by astrocytes, that oxygen modulates blood flow regulation, and that blood flow may be controlled by capillaries as well as by arterioles. These conceptual shifts in our understanding of cerebral blood flow control have important implications for the development of new therapeutic approaches.
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Affiliation(s)
- David Attwell
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
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29
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Marmolino D, Manto M. Past, present and future therapeutics for cerebellar ataxias. Curr Neuropharmacol 2010; 8:41-61. [PMID: 20808545 PMCID: PMC2866461 DOI: 10.2174/157015910790909476] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 11/18/2009] [Accepted: 11/30/2009] [Indexed: 01/14/2023] Open
Abstract
Cerebellar ataxias are a group of disabling neurological disorders. Patients exhibit a cerebellar syndrome and can also present with extra-cerebellar deficits, namely pigmentary retinopathy, extrapyramidal movement disorders, pyramidal signs, cortical symptoms (seizures, cognitive impairment/behavioural symptoms), and peripheral neuropathy. Recently, deficits in cognitive operations have been unraveled. Cerebellar ataxias are heterogeneous both at the phenotypic and genotypic point of view. Therapeutical trials performed during these last 4 decades have failed in most cases, in particular because drugs were not targeting a deleterious pathway, but were given to counteract putative defects in neurotransmission. The identification of the causative mutations of many hereditary ataxias, the development of relevant animal models and the recent identifications of the molecular mechanisms underlying ataxias are impacting on the development of new drugs. We provide an overview of the pharmacological treatments currently used in the clinical practice and we discuss the drugs under development.
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Affiliation(s)
- D Marmolino
- Laboratoire de Neurologie Expèrimentale ULB-Erasme, Brussels, Belgium.
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30
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Cellular in vivo imaging reveals coordinated regulation of pituitary microcirculation and GH cell network function. Proc Natl Acad Sci U S A 2010; 107:4465-70. [PMID: 20160103 DOI: 10.1073/pnas.0902599107] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Growth hormone (GH) exerts its actions via coordinated pulsatile secretion from a GH cell network into the bloodstream. Practically nothing is known about how the network receives its inputs in vivo and releases hormones into pituitary capillaries to shape GH pulses. Here we have developed in vivo approaches to measure local blood flow, oxygen partial pressure, and cell activity at single-cell resolution in mouse pituitary glands in situ. When secretagogue (GHRH) distribution was modeled with fluorescent markers injected into either the bloodstream or the nearby intercapillary space, a restricted distribution gradient evolved within the pituitary parenchyma. Injection of GHRH led to stimulation of both GH cell network activities and GH secretion, which was temporally associated with increases in blood flow rates and oxygen supply by capillaries, as well as oxygen consumption. Moreover, we observed a time-limiting step for hormone output at the perivascular level; macromolecules injected into the extracellular parenchyma moved rapidly to the perivascular space, but were then cleared more slowly in a size-dependent manner into capillary blood. Our findings suggest that GH pulse generation is not simply a GH cell network response, but is shaped by a tissue microenvironment context involving a functional association between the GH cell network activity and fluid microcirculation.
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31
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Aguirre E, Rodríguez-Juárez F, Bellelli A, Gnaiger E, Cadenas S. Kinetic model of the inhibition of respiration by endogenous nitric oxide in intact cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:557-65. [PMID: 20144583 DOI: 10.1016/j.bbabio.2010.01.033] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 01/25/2010] [Accepted: 01/27/2010] [Indexed: 11/24/2022]
Abstract
Nitric oxide (NO) inhibits mitochondrial respiration by decreasing the apparent affinity of cytochrome c oxidase (CcO) for oxygen. Using iNOS-transfected HEK 293 cells to achieve regulated intracellular NO production, we determined NO and O(2) concentrations and mitochondrial O(2) consumption by high-resolution respirometry over a range of O(2) concentrations down to nanomolar. Inhibition of respiration by NO was reversible, and complete NO removal recovered cell respiration above its routine reference values. Respiration was observed even at high NO concentrations, and the dependence of IC(50) on [O(2)] exhibits a characteristic but puzzling parabolic shape; both these features imply that CcO is protected from complete inactivation by NO and are likely to be physiologically relevant. We present a kinetic model of CcO inhibition by NO that efficiently predicts experimentally determined respiration at physiological O(2) and NO concentrations and under hypoxia, and accurately predicts the respiratory responses under hyperoxia. The model invokes competitive and uncompetitive inhibition by binding of NO to the reduced and oxidized forms of CcO, respectively, and suggests that dissociation of NO from reduced CcO may involve its O(2)-dependent oxidation. It also explains the non-linear dependence of IC(50) on O(2) concentration, and the hyperbolic increase of c(50) as a function of NO concentration.
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Affiliation(s)
- Enara Aguirre
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Melchor Fenández Almagro 3, Madrid, Spain
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32
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Casanova D, Bouzigues C, Nguyên TL, Ramodiharilafy RO, Bouzhir-Sima L, Gacoin T, Boilot JP, Tharaux PL, Alexandrou A. Single europium-doped nanoparticles measure temporal pattern of reactive oxygen species production inside cells. NATURE NANOTECHNOLOGY 2009; 4:581-585. [PMID: 19734931 DOI: 10.1038/nnano.2009.200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Accepted: 07/01/2009] [Indexed: 05/26/2023]
Abstract
Low concentrations of reactive oxygen species, notably hydrogen peroxide (H(2)O(2)), mediate various signalling processes in the cell. Production of these signals is highly regulated and a suitable probe is needed to measure these events. Here, we show that a probe based on a single nanoparticle can quantitatively measure transient H(2)O(2) generation in living cells. The Y(0.6)Eu(0.4)VO(4) nanoparticles undergo photoreduction under laser irradiation but re-oxidize in the presence of oxidants, leading to a recovery in luminescence. Our probe can be regenerated and reliably detects intracellular H(2)O(2) with a 30-s temporal resolution and a dynamic range of 1-45 microM. The differences in the timing of intracellular H(2)O(2) production triggered by different signals were also measured using these nanoparticles. Although the probe is not selective towards H(2)O(2), in many signalling processes H(2)O(2) is, however, the dominant oxidant. In conjunction with appropriate controls, this probe is a powerful tool for unravelling pathways that involve reactive oxygen species.
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Affiliation(s)
- Didier Casanova
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM U696, Palaiseau, France
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Hall CN, Garthwaite J. What is the real physiological NO concentration in vivo? Nitric Oxide 2009; 21:92-103. [PMID: 19602444 PMCID: PMC2779337 DOI: 10.1016/j.niox.2009.07.002] [Citation(s) in RCA: 263] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 07/06/2009] [Indexed: 01/10/2023]
Abstract
Clarity about the nitric oxide (NO) concentrations existing physiologically is essential for developing a quantitative understanding of NO signalling, for performing experiments with NO that emulate reality, and for knowing whether or not NO concentrations become abnormal in disease states. A decade ago, a value of about 1 μM seemed reasonable based on early electrode measurements and a provisional estimate of the potency of NO for its guanylyl cyclase-coupled receptors, which mediate physiological NO signal transduction. Since then, numerous efforts to measure NO concentrations directly using electrodes in cells and tissues have yielded an irreconcilably large spread of values. In compensation, data from several alternative approaches have now converged to provide a more coherent picture. These approaches include the quantitative analysis of NO-activated guanylyl cyclase, computer modelling based on the type, activity and amount of NO synthase enzyme contained in cells, the use of novel biosensors to monitor NO release from single endothelial cells and neurones, and the use of guanylyl cyclase as an endogenous NO biosensor in tissue subjected to a variety of challenges. All these independent lines of evidence suggest the physiological NO concentration range to be 100 pM (or below) up to ∼5 nM, orders of magnitude lower than was once thought.
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Affiliation(s)
- Catherine N Hall
- Department of Neuroscience, Physiology and Pharmacology, University College London, UK
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The Neuroscientist Comments. Neuroscientist 2008. [DOI: 10.1177/10738584080140060301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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