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Berkowitz BA, Paruchuri A, Stanek J, Abdul-Nabi M, Podolsky RH, Bustos AH, Childers KL, Murphy GG, Stangis K, Roberts R. Biomarker evidence of early vision and rod energy-linked pathophysiology benefits from very low dose DMSO in 5xFAD mice. Acta Neuropathol Commun 2024; 12:85. [PMID: 38822433 PMCID: PMC11140992 DOI: 10.1186/s40478-024-01799-8] [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: 03/04/2024] [Accepted: 05/20/2024] [Indexed: 06/03/2024] Open
Abstract
Here, we test whether early visual and OCT rod energy-linked biomarkers indicating pathophysiology in nicotinamide nucleotide transhydrogenase (Nnt)-null 5xFAD mice also occur in Nnt-intact 5xFAD mice and whether these biomarkers can be pharmacologically treated. Four-month-old wild-type or 5xFAD C57BL/6 substrains with either a null (B6J) Nnt or intact Nnt gene (B6NTac) and 5xFAD B6J mice treated for one month with either R-carvedilol + vehicle or only vehicle (0.01% DMSO) were studied. The contrast sensitivity (CS), external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness (a proxy for low pH-triggered water removal), profile shape of the hyperreflective band just posterior to the ELM (i.e., the mitochondrial configuration within photoreceptors per aspect ratio [MCP/AR]), and retinal laminar thickness were measured. Both wild-type substrains showed similar visual performance indices and dark-evoked ELM-RPE contraction. The lack of a light-dark change in B6NTac MCP/AR, unlike in B6J mice, is consistent with relatively greater mitochondrial efficiency. 5xFAD B6J mice, but not 5xFAD B6NTac mice, showed lower-than-WT CS. Light-adapted 5xFAD substrains both showed abnormal ELM-RPE contraction and greater-than-WT MCP/AR contraction. The inner retina and superior outer retina were thinner. Treating 5xFAD B6J mice with R-carvedilol + DMSO or DMSO alone corrected CS and ELM-RPE contraction but not supernormal MCP/AR contraction or laminar thinning. These results provide biomarker evidence for prodromal photoreceptor mitochondrial dysfunction/oxidative stress/oxidative damage, which is unrelated to visual performance, as well as the presence of the Nnt gene. This pathophysiology is druggable in 5xFAD mice.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA.
| | - Anuhya Paruchuri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Josh Stanek
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Mura Abdul-Nabi
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, MD, USA
| | | | | | - Geoffrey G Murphy
- Department of Molecular and Integrative Physiology, Molecular Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Katherine Stangis
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
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Patel TA, Kevadiya BD, Bajwa N, Singh PA, Zheng H, Kirabo A, Li YL, Patel KP. Role of Nanoparticle-Conjugates and Nanotheranostics in Abrogating Oxidative Stress and Ameliorating Neuroinflammation. Antioxidants (Basel) 2023; 12:1877. [PMID: 37891956 PMCID: PMC10604131 DOI: 10.3390/antiox12101877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/13/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Oxidative stress is a deteriorating condition that arises due to an imbalance between the reactive oxygen species and the antioxidant system or defense of the body. The key reasons for the development of such conditions are malfunctioning of various cell organelles, such as mitochondria, endoplasmic reticulum, and Golgi complex, as well as physical and mental disturbances. The nervous system has a relatively high utilization of oxygen, thus making it particularly vulnerable to oxidative stress, which eventually leads to neuronal atrophy and death. This advances the development of neuroinflammation and neurodegeneration-associated disorders such as Alzheimer's disease, Parkinson's disease, epilepsy, dementia, and other memory disorders. It is imperative to treat such conditions as early as possible before they worsen and progress to irreversible damage. Oxidative damage can be negated by two mechanisms: improving the cellular defense system or providing exogenous antioxidants. Natural antioxidants can normally handle such oxidative stress, but they have limited efficacy. The valuable features of nanoparticles and/or nanomaterials, in combination with antioxidant features, offer innovative nanotheranostic tools as potential therapeutic modalities. Hence, this review aims to represent novel therapeutic approaches like utilizing nanoparticles with antioxidant properties and nanotheranostics as delivery systems for potential therapeutic applications in various neuroinflammation- and neurodegeneration-associated disease conditions.
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Affiliation(s)
- Tapan A. Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center (UNMC), Omaha, NE 68198, USA;
| | - Bhavesh D. Kevadiya
- Department of Pharmacology and Experimental Neuroscience, College of Medicine, University of Nebraska Medical Center (UNMC), Omaha, NE 68198, USA;
| | - Neha Bajwa
- University Institute of Pharma Sciences (UIPS), Chandigarh University, Mohali 140413, Punjab, India; (N.B.); (P.A.S.)
| | - Preet Amol Singh
- University Institute of Pharma Sciences (UIPS), Chandigarh University, Mohali 140413, Punjab, India; (N.B.); (P.A.S.)
| | - Hong Zheng
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, SD 57069, USA;
| | - Annet Kirabo
- Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center (UNMC), Omaha, NE 68198, USA;
| | - Kaushik P. Patel
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center (UNMC), Omaha, NE 68198, USA;
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3
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Cartwright IM, Dowdell AS, Hanson C, Kostelecky RE, Welch N, Steiner CA, Colgan SP. Contact-dependent, polarized acidification response during neutrophil-epithelial interactions. J Leukoc Biol 2022; 112:1543-1553. [PMID: 35674095 PMCID: PMC9701153 DOI: 10.1002/jlb.3ma0422-742r] [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: 03/14/2022] [Revised: 04/29/2022] [Indexed: 01/04/2023] Open
Abstract
Neutrophil (PMN) infiltration during active inflammation imprints changes in the local tissue environment. Such responses are often accompanied by significant extracellular acidosis that result in predictable transcriptional responses. In this study, we explore the mechanisms involved in inflammatory acidification as a result of PMN-intestinal epithelial cell (IEC) interactions. Using recently developed tools, we revealed that PMN transepithelial migration (TEM)-associated inflammatory acidosis is dependent on the total number of PMNs present during TEM and is polarized toward the apical surface. Extending these studies, we demonstrate that physical separation of the PMNs and IECs prevented acidification, whereas inhibition of PMN TEM using neutralizing antibodies enhanced extracellular acidification. Utilizing pharmaceutical inhibitors, we demonstrate that the acidification response is independent of myeloperoxidase and dependent on reactive oxygen species generated during PMN TEM. In conclusion, inflammatory acidosis represents a polarized PMN-IEC-dependent response by an as yet to be fully determined mechanism.
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Affiliation(s)
- Ian M. Cartwright
- Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado, USA
| | - Alexander S. Dowdell
- Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Camila Hanson
- Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado, USA
| | - Rachael E. Kostelecky
- Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Nichole Welch
- Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Calen A. Steiner
- Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Sean P. Colgan
- Mucosal Inflammation Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado, USA
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Dean JB, Stavitzski NM. The O2-sensitive brain stem, hyperoxic hyperventilation, and CNS oxygen toxicity. Front Physiol 2022; 13:921470. [PMID: 35957982 PMCID: PMC9360621 DOI: 10.3389/fphys.2022.921470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Central nervous system oxygen toxicity (CNS-OT) is a complex disorder that presents, initially, as a sequence of cardio-respiratory abnormalities and nonconvulsive signs and symptoms (S/Sx) of brain stem origin that culminate in generalized seizures, loss of consciousness, and postictal cardiogenic pulmonary edema. The risk of CNS-OT and its antecedent “early toxic indications” are what limits the use of hyperbaric oxygen (HBO2) in hyperbaric and undersea medicine. The purpose of this review is to illustrate, based on animal research, how the temporal pattern of abnormal brain stem responses that precedes an “oxtox hit” provides researchers a window into the early neurological events underlying seizure genesis. Specifically, we focus on the phenomenon of hyperoxic hyperventilation, and the medullary neurons presumed to contribute in large part to this paradoxical respiratory response; neurons in the caudal Solitary complex (cSC) of the dorsomedial medulla, including putative CO2 chemoreceptor neurons. The electrophysiological and redox properties of O2-/CO2-sensitive cSC neurons identified in rat brain slice experiments are summarized. Additionally, evidence is summarized that supports the working hypothesis that seizure genesis originates in subcortical areas and involves cardio-respiratory centers and cranial nerve nuclei in the hind brain (brainstem and cerebellum) based on, respectively, the complex temporal pattern of abnormal cardio-respiratory responses and various nonconvulsive S/Sx that precede seizures during exposure to HBO2.
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5
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Probing altered enzyme activity in the biochemical characterization of cancer. Biosci Rep 2022; 42:230680. [PMID: 35048115 PMCID: PMC8819661 DOI: 10.1042/bsr20212002] [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: 11/16/2021] [Revised: 01/10/2022] [Accepted: 01/19/2022] [Indexed: 11/30/2022] Open
Abstract
Enzymes have evolved to catalyze their precise reactions at the necessary rates, locations, and time to facilitate our development, to respond to a variety of insults and challenges, and to maintain a healthy, balanced state. Enzymes achieve this extraordinary feat through their unique kinetic parameters, myriad regulatory strategies, and their sensitivity to their surroundings, including substrate concentration and pH. The Cancer Genome Atlas (TCGA) highlights the extraordinary number of ways in which the finely tuned activities of enzymes can be disrupted, contributing to cancer development and progression often due to somatic and/or inherited genetic alterations. Rather than being limited to the domain of enzymologists, kinetic constants such as kcat, Km, and kcat/Km are highly informative parameters that can impact a cancer patient in tangible ways—these parameters can be used to sort tumor driver mutations from passenger mutations, to establish the pathways that cancer cells rely on to drive patients’ tumors, to evaluate the selectivity and efficacy of anti-cancer drugs, to identify mechanisms of resistance to treatment, and more. In this review, we will discuss how changes in enzyme activity, primarily through somatic mutation, can lead to altered kinetic parameters, new activities, or changes in conformation and oligomerization. We will also address how changes in the tumor microenvironment can affect enzymatic activity, and briefly describe how enzymology, when combined with additional powerful tools, and can provide us with tremendous insight into the chemical and molecular mechanisms of cancer.
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Mohanraj N, Joshi NS, Poulose R, Patil RR, Santhoshkumar R, Kumar A, Waghmare GP, Saha AK, Haider SZ, Markandeya YS, Dey G, Rao LT, Govindaraj P, Mehta B. A proteomic study to unveil lead toxicity-induced memory impairments invoked by synaptic dysregulation. Toxicol Rep 2022; 9:1501-1513. [DOI: 10.1016/j.toxrep.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/02/2022] [Accepted: 07/05/2022] [Indexed: 11/17/2022] Open
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7
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Berkowitz BA, Qian H. OCT imaging of rod mitochondrial respiration in vivo. Exp Biol Med (Maywood) 2021; 246:2151-2158. [PMID: 34024141 DOI: 10.1177/15353702211013799] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
There remains a need for high spatial resolution imaging indices of mitochondrial respiration in the outer retina that probe normal physiology and measure pathogenic and reversible conditions underlying loss of vision. Mitochondria are involved in a critical, but somewhat underappreciated, support system that maintains the health of the outer retina involving stimulus-evoked changes in subretinal space hydration. The subretinal space hydration light-dark response is important because it controls the distribution of vision-critical interphotoreceptor matrix components, including anti-oxidants, pro-survival factors, ions, and metabolites. The underlying signaling pathway controlling subretinal space water management has been worked out over the past 30 years and involves cGMP/mitochondria respiration/pH/RPE water efflux. This signaling pathway has also been shown to be modified by disease-generating conditions, such as hypoxia or oxidative stress. Here, we review recent advances in MRI and commercially available OCT technologies that can measure stimulus-evoked changes in subretinal space water content based on changes in the external limiting membrane-retinal pigment epithelium region. Each step within the above signaling pathway can also be interrogated with FDA-approved pharmaceuticals. A highlight of these studies is the demonstration of first-in-kind in vivo imaging of mitochondria respiration of any cell in the body. Future examinations of subretinal space hydration are expected to be useful for diagnosing threats to sight in aging and disease, and improving the success rate when translating treatments from bench-to-bedside.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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8
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Hinojo CM, Ciarlone GE, D'Agostino DP, Dean JB. Exogenous ketone salts inhibit superoxide production in the rat caudal solitary complex during exposure to normobaric and hyperbaric hyperoxia. J Appl Physiol (1985) 2021; 130:1936-1954. [PMID: 33661724 DOI: 10.1152/japplphysiol.01071.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The use of hyperbaric oxygen (HBO2) in hyperbaric and undersea medicine is limited by the risk of seizures [i.e., central nervous system (CNS) oxygen toxicity, CNS-OT] resulting from increased production of reactive oxygen species (ROS) in the CNS. Importantly, ketone supplementation has been shown to delay onset of CNS-OT in rats by ∼600% in comparison with control groups (D'Agostino DP, Pilla R, Held HE, Landon CS, Puchowicz M, Brunengraber H, Ari C, Arnold P, Dean JB. Am J Physiol Regu Integr Comp Physiol 304: R829-R836, 2013). We have tested the hypothesis that ketone body supplementation inhibits ROS production during exposure to hyperoxygenation in rat brainstem cells. We measured the rate of cellular superoxide ([Formula: see text]) production in the caudal solitary complex (cSC) in rat brain slices using a fluorogenic dye, dihydroethidium (DHE), during exposure to control O2 (0.4 ATA) followed by 1-2 h of normobaric oxygen (NBO2) (0.95 ATA) and HBO2 (1.95, and 4.95 ATA) hyperoxia, with and without a 50:50 mixture of ketone salts (KS) dl-β-hydroxybutyrate + acetoacetate. All levels of hyperoxia tested stimulated [Formula: see text] production similarly in cSC cells and coexposure to 5 mM KS during hyperoxia significantly blunted the rate of increase in DHE fluorescence intensity during exposure to hyperoxia. Not all cells tested produced [Formula: see text] at the same rate during exposure to control O2 and hyperoxygenation; cells that increased [Formula: see text] production by >25% during hyperoxia in comparison with baseline were inhibited by KS, whereas cells that did not reach that threshold during hyperoxia were unaffected by KS. These findings support the hypothesis that ketone supplementation decreases the steady-state concentrations of superoxide produced during exposure to NBO2 and HBO2 hyperoxia.NEW & NOTEWORTHY Exposure of rat medullary tissue slices to levels of O2 that mimic those that cause seizures in rats stimulates cellular superoxide ([Formula: see text]) production to varying degrees. Cellular [Formula: see text] generation in the caudal solitary complex is variable during exposure to control O2 and hyperoxia and significantly decreases during ketone supplementation. Our findings support the theory that ketone supplementation delays onset of central nervous system oxygen toxicity in mammals, in part, by decreasing [Formula: see text] production in O2-sensitive neurons.
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Affiliation(s)
- Christopher M Hinojo
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, MDC 8, University of South Florida, Tampa, Florida
| | - Geoffrey E Ciarlone
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, MDC 8, University of South Florida, Tampa, Florida
| | - Dominic P D'Agostino
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, MDC 8, University of South Florida, Tampa, Florida.,Institute of Human and Machine Cognition, Ocala, Florida
| | - Jay B Dean
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, MDC 8, University of South Florida, Tampa, Florida
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Sildenafil-evoked photoreceptor oxidative stress in vivo is unrelated to impaired visual performance in mice. PLoS One 2021; 16:e0245161. [PMID: 33661941 PMCID: PMC7932139 DOI: 10.1371/journal.pone.0245161] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 12/22/2020] [Indexed: 12/22/2022] Open
Abstract
Purpose The phosphodiesterase inhibitor sildenafil is a promising treatment for neurodegenerative disease, but it can cause oxidative stress in photoreceptors ex vivo and degrade visual performance in humans. Here, we test the hypotheses that in wildtype mice sildenafil causes i) wide-spread photoreceptor oxidative stress in vivo that is linked with ii) impaired vision. Methods In dark or light-adapted C57BL/6 mice ± sildenafil treatment, the presence of oxidative stress was evaluated in retina laminae in vivo by QUEnch-assiSTed (QUEST) magnetic resonance imaging, in the subretinal space in vivo by QUEST optical coherence tomography, and in freshly excised retina by a dichlorofluorescein assay. Visual performance indices were also evaluated by QUEST optokinetic tracking. Results In light-adapted mice, 1 hr post-sildenafil administration, oxidative stress was most evident in the superior peripheral outer retina on both in vivo and ex vivo examinations; little evidence was noted for central retina oxidative stress in vivo and ex vivo. In dark-adapted mice 1 hr after sildenafil, no evidence for outer retina oxidative stress was found in vivo. Evidence for sildenafil-induced central retina rod cGMP accumulation was suggested as a panretinally thinner, dark-like subretinal space thickness in light-adapted mice at 1 hr but not 5 hr post-sildenafil. Cone-based visual performance was impaired by 5 hr post-sildenafil and not corrected with anti-oxidants; vision was normal at 1 hr and 24 hr post-sildenafil. Conclusions The sildenafil-induced spatiotemporal pattern of oxidative stress in photoreceptors dominated by rods was unrelated to impairment of cone-based visual performance in wildtype mice.
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10
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An acidic residue buried in the dimer interface of isocitrate dehydrogenase 1 (IDH1) helps regulate catalysis and pH sensitivity. Biochem J 2021; 477:2999-3018. [PMID: 32729927 DOI: 10.1042/bcj20200311] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/19/2022]
Abstract
Isocitrate dehydrogenase 1 (IDH1) catalyzes the reversible NADP+-dependent conversion of isocitrate to α-ketoglutarate (αKG) to provide critical cytosolic substrates and drive NADPH-dependent reactions like lipid biosynthesis and glutathione regeneration. In biochemical studies, the forward reaction is studied at neutral pH, while the reverse reaction is typically characterized in more acidic buffers. This led us to question whether IDH1 catalysis is pH-regulated, which would have functional implications under conditions that alter cellular pH, like apoptosis, hypoxia, cancer, and neurodegenerative diseases. Here, we show evidence of catalytic regulation of IDH1 by pH, identifying a trend of increasing kcat values for αKG production upon increasing pH in the buffers we tested. To understand the molecular determinants of IDH1 pH sensitivity, we used the pHinder algorithm to identify buried ionizable residues predicted to have shifted pKa values. Such residues can serve as pH sensors, with changes in protonation states leading to conformational changes that regulate catalysis. We identified an acidic residue buried at the IDH1 dimer interface, D273, with a predicted pKa value upshifted into the physiological range. D273 point mutations had decreased catalytic efficiency and, importantly, loss of pH-regulated catalysis. Based on these findings, we conclude that IDH1 activity is regulated, at least in part, by pH. We show this regulation is mediated by at least one buried acidic residue ∼12 Å from the IDH1 active site. By establishing mechanisms of regulation of this well-conserved enzyme, we highlight catalytic features that may be susceptible to pH changes caused by cell stress and disease.
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11
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Graham C, Santiago-Mugica E, Abdel-All Z, Li M, McNally R, Kalaria RN, Mukaetova-Ladinska EB. Erythrocytes as Biomarkers for Dementia: Analysis of Protein Content and Alpha-Synuclein. J Alzheimers Dis 2020; 71:569-580. [PMID: 31424413 DOI: 10.3233/jad-190567] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Discovering biomarkers for dementia is a pivotal step toward successful early diagnosis and treatment. Although plasma biomarkers have been explored, no consensus has been reached. Alpha-synuclein (AS), a 14 kDa synaptic protein associated with several neurodegenerative diseases, exists natively within erythrocytes (ERC). This protein is characteristic of Lewy body diseases, in which it aggregates into toxic Lewy bodies. As ERC are implicated in dementia, they are a potential target for future biomarkers. OBJECTIVE The aims of this study were to assess AS levels within ERC and whether AS can be used as a peripheral biomarker to differentiate between dementia and aged matched healthy control subjects. METHODS A total of 114 samples (60 aging controls, 36 Alzheimer's disease, 12 vascular dementia (VaD) and 6 dementia with Lewy bodies (DLB) subjects) were analyzed. We used Bradford assay to measure protein concentration, indirect ELISA to detect levels of AS, and immunoblotting to identify AS composition. Data were analyzed with nonparametric tests. RESULTS AS oligomers were present in dementia blood samples, whereas in controls, AS was largely monomeric. There was a significant increase in AS levels in DLB whole blood (p = 0.005; Kruskal-Wallis test), with a sensitivity and specificity of 100.0% and 93.9%. Protein concentrations in ERC isolated at pH 5.7 were significantly increased in dementia patients compared to controls (17.58 versus 40.33μg/ml; p≤0.005; Mann-Whitney test). In the VaD group, the protein concentration in the pH5.7 ERC fraction had sensitivity and specificity of 91.7% and 62.1%. CONCLUSIONS ERC protein concentration and AS levels have a potential for development of a novel diagnostic dementia blood test.
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Affiliation(s)
- Charlotte Graham
- Institute of Neuroscience, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | | | - Zeinab Abdel-All
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Mosi Li
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh, UK
| | - Richard McNally
- Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
| | - Rajesh N Kalaria
- Institute of Neuroscience, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | - Elizabeta B Mukaetova-Ladinska
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK.,The Evington Centre, Leicestershire Partnership NHS Trust, Leicester General Hospital, Leicester, UK
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12
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Abstract
Patients with diabetes continue to suffer from impaired visual performance before the appearance of overt damage to the retinal microvasculature and later sight-threatening complications. This diabetic retinopathy (DR) has long been thought to start with endothelial cell oxidative stress. Yet newer data surprisingly finds that the avascular outer retina is the primary site of oxidative stress before microvascular histopathology in experimental DR. Importantly, correcting this early oxidative stress is sufficient to restore vision and mitigate the histopathology in diabetic models. However, translating these promising results into the clinic has been stymied by an absence of methods that can measure and optimize anti-oxidant treatment efficacy in vivo. Here, we review imaging approaches that address this problem. In particular, diabetes-induced oxidative stress impairs dark-light regulation of subretinal space hydration, which regulates the distribution of interphotoreceptor binding protein (IRBP). IRBP is a vision-critical, anti-oxidant, lipid transporter, and pro-survival factor. We show how optical coherence tomography can measure subretinal space oxidative stress thus setting the stage for personalizing anti-oxidant treatment and prevention of impactful declines and loss of vision in patients with diabetes.
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13
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Abstract
Air-breathing animals do not experience hyperoxia (inspired O2 > 21%) in nature, but preterm and full-term infants often experience hyperoxia/hyperoxemia in clinical settings. This article focuses on the effects of normobaric hyperoxia during the perinatal period on breathing in humans and other mammals, with an emphasis on the neural control of breathing during hyperoxia, after return to normoxia, and in response to subsequent hypoxic and hypercapnic challenges. Acute hyperoxia typically evokes an immediate ventilatory depression that is often, but not always, followed by hyperpnea. The hypoxic ventilatory response (HVR) is enhanced by brief periods of hyperoxia in adult mammals, but the limited data available suggest that this may not be the case for newborns. Chronic exposure to mild-to-moderate levels of hyperoxia (e.g., 30-60% O2 for several days to a few weeks) elicits several changes in breathing in nonhuman animals, some of which are unique to perinatal exposures (i.e., developmental plasticity). Examples of this developmental plasticity include hypoventilation after return to normoxia and long-lasting attenuation of the HVR. Although both peripheral and CNS mechanisms are implicated in hyperoxia-induced plasticity, it is particularly clear that perinatal hyperoxia affects carotid body development. Some of these effects may be transient (e.g., decreased O2 sensitivity of carotid body glomus cells) while others may be permanent (e.g., carotid body hypoplasia, loss of chemoafferent neurons). Whether the hyperoxic exposures routinely experienced by human infants in clinical settings are sufficient to alter respiratory control development remains an open question and requires further research. © 2020 American Physiological Society. Compr Physiol 10:597-636, 2020.
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Affiliation(s)
- Ryan W Bavis
- Department of Biology, Bates College, Lewiston, Maine, USA
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14
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Wang X, Bai X, Su D, Zhang Y, Li P, Lu S, Gong Y, Zhang W, Tang B. Simultaneous Fluorescence Imaging Reveals N-Methyl-d-aspartic Acid Receptor Dependent Zn 2+/H + Flux in the Brains of Mice with Depression. Anal Chem 2020; 92:4101-4107. [PMID: 32037810 DOI: 10.1021/acs.analchem.9b05771] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Depression is immensely attributed to the overactivation of N-methyl-d-aspartic acid (NMDA) receptor in the brains. As regulatory binding partners of NMDA receptor, both Zn2+ and H+ are intimately interrelated to NMDA receptor's activity. Therefore, exploring synergistic changes on the levels of Zn2+ and H+ in brains will promote the knowledge and treatment of depression. However, the lack of efficient, appropriate imaging tools limits simultaneously tracking Zn2+ and H+ in living mouse brains. Thus, a well-designed dual-color fluorescent probe (DNP) was fabricated for the simultaneous monitoring of Zn2+ and H+ in the brains of mice with depression. Encountering Zn2+, the probe evoked bright blue fluorescence at 460 nm. Meanwhile, the red fluorescence at 680 nm was decreased with H+ addition. With blue/red dual fluorescence signal of DNP, we observed the synchronous increased Zn2+ and H+ in PC12 cells under oxidative stress. Notably, in vivo imaging for the first time revealed the simultaneous reduction of Zn2+ and pH in brains of mice with depression-like behaviors. Further results implied that the NMDA receptor might be responsible for the coinstantaneous fluctuation of Zn2+ and H+ during depression. Altogether, this work is conducive to the knowledge of neural signal transduction mechanisms, advancing our understanding of the pathogenesis in depression.
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Affiliation(s)
- Xin Wang
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
| | - Xiaoyi Bai
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
| | - Di Su
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
| | - Yandi Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
| | - Ping Li
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
| | - Shuyi Lu
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
| | - Yulin Gong
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
| | - Wen Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
| | - Bo Tang
- College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institutes of Biomedical Sciences, Shandong Normal University, Jinan 250014, People's Republic of China
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Bulat K, Dybas J, Kaczmarska M, Rygula A, Jasztal A, Szczesny-Malysiak E, Baranska M, Wood BR, Marzec KM. Multimodal detection and analysis of a new type of advanced Heinz body-like aggregate (AHBA) and cytoskeleton deformation in human RBCs. Analyst 2020; 145:1749-1758. [PMID: 31913373 DOI: 10.1039/c9an01707k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new type of aggregate, formed in human red blood cells (RBCs) in response to glutaraldehyde treatment, was discovered and analyzed with the classical and advanced biomolecular imaging techniques. Advanced Heinz body-like aggregates (AHBA) formed in a single human RBC are characterized by a higher level of hemoglobin (Hb) degradation compared to typical Heinz bodies, which consist of hemichromes. The complete destruction of the porphyrin structure of Hb and the aggregation of the degraded proteins in the presence of Fe3+ ions are observed. The presence of such aggregated, highly degraded proteins inside RBCs, without cell membrane destruction, has been never reported before. For the first time the spatial differentiation of two kinds of protein mixtures inside a single RBC, with different phenylalanine (Phe) conformations, is visualized. The non-resonant Raman spectra of altered RBCs with AHBA are characterized by the presence of a strong band located at 1037 cm-1, which confirms that glutaraldehyde interacts strongly with Phe. The shape-shifting of RBCs from a biconcave disk to a spherical structure and sinking of AHBA to the bottom of the cell are observed. Results reveal that the presence of AHBA should be considered when fixing RBCs and indicate the analytical potential of Raman spectroscopy, atomic force microscopy and scanning near-field optical microscopy in AHBA detection and analysis.
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Affiliation(s)
- Katarzyna Bulat
- Jagiellonian Center for Experimental Therapeutics, Jagiellonian University, 14 Bobrzynskiego Str., 30-348 Krakow, Poland.
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Ciarlone GE, Hinojo CM, Stavitzski NM, Dean JB. CNS function and dysfunction during exposure to hyperbaric oxygen in operational and clinical settings. Redox Biol 2019; 27:101159. [PMID: 30902504 PMCID: PMC6859559 DOI: 10.1016/j.redox.2019.101159] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/20/2019] [Accepted: 03/01/2019] [Indexed: 12/26/2022] Open
Abstract
Hyperbaric oxygen (HBO2) is breathed during hyperbaric oxygen therapy and during certain undersea pursuits in diving and submarine operations. What limits exposure to HBO2 in these situations is the acute onset of central nervous system oxygen toxicity (CNS-OT) following a latent period of safe oxygen breathing. CNS-OT presents as various non-convulsive signs and symptoms, many of which appear to be of brainstem origin involving cranial nerve nuclei and autonomic and cardiorespiratory centers, which ultimately spread to higher cortical centers and terminate as generalized tonic-clonic seizures. The initial safe latent period makes the use of HBO2 practical in hyperbaric and undersea medicine; however, the latent period is highly variable between individuals and within the same individual on different days, making it difficult to predict onset of toxic indications. Consequently, currently accepted guidelines for safe HBO2 exposure are highly conservative. This review examines the disorder of CNS-OT and summarizes current ideas on its underlying pathophysiology, including specific areas of the CNS and fundamental neural and redox signaling mechanisms that are thought to be involved in seizure genesis and propagation. In addition, conditions that accelerate the onset of seizures are discussed, as are current mitigation strategies under investigation for neuroprotection against redox stress while breathing HBO2 that extend the latent period, thus enabling safer and longer exposures for diving and medical therapies.
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Affiliation(s)
- Geoffrey E Ciarlone
- Undersea Medicine Department, Naval Medical Research Center, 503 Robert Grant Ave., Silver Spring, MD, USA
| | - Christopher M Hinojo
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Nicole M Stavitzski
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Jay B Dean
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.
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17
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Nucifora LG, MacDonald ML, Lee BJ, Peters ME, Norris AL, Orsburn BC, Yang K, Gleason K, Margolis RL, Pevsner J, Tamminga CA, Sweet RA, Ross CA, Sawa A, Nucifora FC. Increased Protein Insolubility in Brains From a Subset of Patients With Schizophrenia. Am J Psychiatry 2019; 176:730-743. [PMID: 31055969 DOI: 10.1176/appi.ajp.2019.18070864] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The mechanisms leading to schizophrenia are likely to be diverse. However, there may be common pathophysiological pathways for subtypes of the disease. The authors tested the hypothesis that increased protein insolubility and ubiquitination underlie the pathophysiology for a subtype of schizophrenia. METHODS Prefrontal cortex and superior temporal gyrus from postmortem brains of individuals with and without schizophrenia were subjected to cold sarkosyl fractionation, separating proteins into soluble and insoluble fractions. Protein insolubility and ubiquitin levels were quantified for each insoluble fraction, with normalization to total homogenate protein. Mass spectrometry analysis was then performed to identify the protein contents of the insoluble fractions. The potential biological relevance of the detected proteins was assessed using Gene Ontology enrichment analysis and Ingenuity Pathway Analysis. RESULTS A subset of the schizophrenia brains showed an increase in protein insolubility and ubiquitination in the insoluble fraction. Mass spectrometry of the insoluble fraction revealed that brains with increased insolubility and ubiquitination exhibited a similar peptide expression by principal component analysis. The proteins that were significantly altered in the insoluble fraction were enriched for pathways relating to axon target recognition as well as nervous system development and function. CONCLUSIONS This study suggests a pathological process related to protein insolubility for a subset of patients with schizophrenia. Determining the molecular mechanism of this subtype of schizophrenia could lead to a better understanding of the pathways underlying the clinical phenotype in some patients with major mental illness as well as to improved nosology and identification of novel therapeutic targets.
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Affiliation(s)
- Leslie G Nucifora
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Matthew L MacDonald
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Brian J Lee
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Matthew E Peters
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Alexis L Norris
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Benjamin C Orsburn
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Kun Yang
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Kelly Gleason
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Russell L Margolis
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Jonathan Pevsner
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Carol A Tamminga
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Robert A Sweet
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Christopher A Ross
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Akira Sawa
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
| | - Frederick C Nucifora
- The Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore (L.G. Nucifora, Lee, Peters, Yang, Margolis, Pevsner, Ross, Sawa, F.C. Nucifora); the Departments of Psychiatry and Neurology, University of Pittsburgh, and the VISN 4 Mental Illness Research, Education, and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh (MacDonald, Sweet); the Department of Neurology, Kennedy Krieger Institute, Baltimore (Norris, Pevsner); the Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore (Norris, Pevsner, Ross, Sawa); Protein Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Md. (Orsburn); the Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas (Gleason, Tamminga); the Department of Neurology, Johns Hopkins University School of Medicine, Baltimore (Margolis, Ross, Sawa, F.C. Nucifora); Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore (Lee, Sawa); the Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore (Ross)
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Brugniaux JV, Coombs GB, Barak OF, Dujic Z, Sekhon MS, Ainslie PN. Highs and lows of hyperoxia: physiological, performance, and clinical aspects. Am J Physiol Regul Integr Comp Physiol 2018; 315:R1-R27. [PMID: 29488785 DOI: 10.1152/ajpregu.00165.2017] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Molecular oxygen (O2) is a vital element in human survival and plays a major role in a diverse range of biological and physiological processes. Although normobaric hyperoxia can increase arterial oxygen content ([Formula: see text]), it also causes vasoconstriction and hence reduces O2 delivery in various vascular beds, including the heart, skeletal muscle, and brain. Thus, a seemingly paradoxical situation exists in which the administration of oxygen may place tissues at increased risk of hypoxic stress. Nevertheless, with various degrees of effectiveness, and not without consequences, supplemental oxygen is used clinically in an attempt to correct tissue hypoxia (e.g., brain ischemia, traumatic brain injury, carbon monoxide poisoning, etc.) and chronic hypoxemia (e.g., severe COPD, etc.) and to help with wound healing, necrosis, or reperfusion injuries (e.g., compromised grafts). Hyperoxia has also been used liberally by athletes in a belief that it offers performance-enhancing benefits; such benefits also extend to hypoxemic patients both at rest and during rehabilitation. This review aims to provide a comprehensive overview of the effects of hyperoxia in humans from the "bench to bedside." The first section will focus on the basic physiological principles of partial pressure of arterial O2, [Formula: see text], and barometric pressure and how these changes lead to variation in regional O2 delivery. This review provides an overview of the evidence for and against the use of hyperoxia as an aid to enhance physical performance. The final section addresses pathophysiological concepts, clinical studies, and implications for therapy. The potential of O2 toxicity and future research directions are also considered.
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Affiliation(s)
| | - Geoff B Coombs
- Centre for Heart, Lung, and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada
| | - Otto F Barak
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia.,Faculty of Sport and Physical Education, University of Novi Sad, Novi Sad, Serbia
| | - Zeljko Dujic
- Department of Integrative Physiology, School of Medicine, University of Split , Split , Croatia
| | - Mypinder S Sekhon
- Centre for Heart, Lung, and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada.,Division of Critical Care Medicine, Department of Medicine, Vancouver General Hospital, University of British Columbia , Vancouver, British Columbia , Canada
| | - Philip N Ainslie
- Centre for Heart, Lung, and Vascular Health, University of British Columbia , Kelowna, British Columbia , Canada
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Squecco R, Luciani P, Idrizaj E, Deledda C, Benvenuti S, Giuliani C, Fibbi B, Peri A, Francini F. Hyponatraemia alters the biophysical properties of neuronal cells independently of osmolarity: a study on Ni(2+) -sensitive current involvement. Exp Physiol 2018; 101:1086-100. [PMID: 27307205 DOI: 10.1113/ep085806] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/13/2016] [Indexed: 12/28/2022]
Abstract
What is the central question of this study? Hyponatraemia, an electrolyte disorder encountered in hospitalized patients, can cause neurological symptoms usually attributed to a reduction in plasma osmolarity. Here, we investigated whether low [Na(+) ] per se can cause neuronal changes independent of osmolarity, focusing on involvement of the Na(+) -Ca(2+) exchanger. What is the main finding and its importance? We show that hyponatraemia per se causes alterations of neuronal properties. The novel finding of Na(+) -Ca(2+) exchanger involvement helps us to elucidate the volume regulation following hyponatraemia. This might have relevance in a translational perspective because Na(+) -Ca(2+) exchanger could be a target for novel therapies. Hyponatraemia is the most frequent electrolyte disorder encountered in hospitalized patients, and it can cause a wide variety of neurological symptoms. Most of the negative effects of this condition on neuronal cells are attributed to cell swelling because of the reduction of plasma osmolarity, although in hyponatraemia different membrane proteins are supposed to be involved in the conservation of neuronal volume. We have recently reported detrimental effects of hyponatraemia on two different neuronal cell lines, SK-N-AS and SH-SY5Y, independent of osmotic alterations. In this study we investigated, in the same cell lines, whether hyponatraemic conditions per se can cause electrophysiological alterations and whether these effects vary over time. Accordingly, we carried out experiments in low-sodium medium in either hyposmotic [Osm(-)] or isosmotic [Osm(+)] conditions, for a short (24 h) or long time (7 days). Using a patch pipette in voltage-clamp conditions, we recorded possible modifications of cell capacitance (Cm ) and membrane conductance (Gm ). Our results indicate that in both Osm(-) and Osm(+) medium, Cm and Gm show a similar increase, but such effects are dependent on the time in culture in different ways. Notably, regarding the possible mechanisms involved in the maintenance of Cm , Gm and Gm /Cm in Osm(+) conditions, we observed a greater contribution of the Na(+) -Ca(2+) exchanger compared with Osm(-) and control conditions. Overall, these novel electrophysiological results help us to understand the mechanisms of volume regulation after ionic perturbation. Our results might also have relevance in a translational perspective because the Na(+) -Ca(2+) exchanger can be considered a target for planning novel therapies.
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Affiliation(s)
- Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, 50134, Florence, Italy
| | - Paola Luciani
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, 50134, Florence, Italy
| | - Eglantina Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, 50134, Florence, Italy
| | - Cristiana Deledda
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, 50134, Florence, Italy
| | - Susanna Benvenuti
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, 50134, Florence, Italy
| | - Corinna Giuliani
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, 50134, Florence, Italy
| | - Benedetta Fibbi
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, 50134, Florence, Italy
| | - Alessandro Peri
- Department of Experimental and Clinical Biomedical Sciences 'Mario Serio', University of Florence, 50134, Florence, Italy
| | - Fabio Francini
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, 50134, Florence, Italy
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20
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Thétiot-Laurent S, Gosset G, Clément JL, Cassien M, Mercier A, Siri D, Gaudel-Siri A, Rockenbauer A, Culcasi M, Pietri S. New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy. Chembiochem 2016; 18:300-315. [DOI: 10.1002/cbic.201600550] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Indexed: 01/06/2023]
Affiliation(s)
- Sophie Thétiot-Laurent
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Gaëlle Gosset
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Jean-Louis Clément
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Mathieu Cassien
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Anne Mercier
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Didier Siri
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Anouk Gaudel-Siri
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Antal Rockenbauer
- Research Centre for Natural Sciences of the Hungarian Academy of Sciences; Institute of Materials and Environmental Chemistry; Budapest University of Technology and Economics; 1117 Budapest Hungary
| | - Marcel Culcasi
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Sylvia Pietri
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
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21
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Domoto H, Iwaya K, Ikomi F, Matsuo H, Tadano Y, Fujii S, Tachi K, Itoh Y, Sato M, Inoue K, Shinomiya N. Up-Regulation of Antioxidant Proteins in the Plasma Proteome during Saturation Diving: Unique Coincidence under Hypobaric Hypoxia. PLoS One 2016; 11:e0163804. [PMID: 27741252 PMCID: PMC5065185 DOI: 10.1371/journal.pone.0163804] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 09/14/2016] [Indexed: 01/04/2023] Open
Abstract
Saturation diving (SD) is one of the safest techniques for tolerating hyperbaric conditions for long durations. However, the changes in the human plasma protein profile that occur during SD are unknown. To identify differential protein expression during or after SD, 65 blood samples from 15 healthy Japanese men trained in SD were analyzed by two-dimensional fluorescence difference gel electrophoresis. The expression of two proteins, one 32.4 kDa with an isoelectric point (pI) of 5.8 and the other 44.8 kDa with pI 4.0, were elevated during SD to 60, 100, and 200 meters sea water (msw). The expression of these proteins returned to pre-diving level when the SD training was completed. The two proteins were identified using in-gel digestion and mass spectrometric analysis; the 32.4 kDa protein was transthyretin and the 44.8 kDa protein was alpha-1-acid glycoprotein 1. Oxidation was detected at methionine 13 of transthyretin and at methionine 129 of alpha-1-acid glycoprotein 1 by tandem mass spectrometry. Moreover, haptoglobin was up-regulated during the decompression phase of 200 msw. These plasma proteins up-regulated during SD have a common function as anti-oxidants. This suggests that by coordinating their biological effects, these proteins activate a defense mechanism to counteract the effects of hyperbaric-hyperoxic conditions during SD.
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Affiliation(s)
- Hideharu Domoto
- Research Division, Maritime Self-Defense Force Undersea Medical Center, Yokosuka, Kanagawa, Japan
| | - Keiichi Iwaya
- Department of Pathology, SASAKI Institute, Kyoundo Hospital, Chiyoda, Tokyo, Japan
- * E-mail:
| | - Fumitaka Ikomi
- National Defense Medical College Research Institute, Tokorozawa, Saitama, Japan
| | - Hirotaka Matsuo
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Yutaka Tadano
- Research Division, Maritime Self-Defense Force Undersea Medical Center, Yokosuka, Kanagawa, Japan
| | - Shigenori Fujii
- Research Division, Maritime Self-Defense Force Undersea Medical Center, Yokosuka, Kanagawa, Japan
| | - Kazuyoshi Tachi
- Research Division, Maritime Self-Defense Force Undersea Medical Center, Yokosuka, Kanagawa, Japan
| | | | - Michiya Sato
- Research Division, Maritime Self-Defense Force Undersea Medical Center, Yokosuka, Kanagawa, Japan
| | - Kimitoshi Inoue
- Research Division, Maritime Self-Defense Force Undersea Medical Center, Yokosuka, Kanagawa, Japan
| | - Nariyoshi Shinomiya
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
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22
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Ciarlone GE, Dean JB. Normobaric hyperoxia stimulates superoxide and nitric oxide production in the caudal solitary complex of rat brain slices. Am J Physiol Cell Physiol 2016; 311:C1014-C1026. [PMID: 27733362 DOI: 10.1152/ajpcell.00160.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/05/2016] [Indexed: 12/25/2022]
Abstract
Central CO2-chemosensitive neurons in the caudal solitary complex (cSC) are stimulated not only by hypercapnic acidosis, but by hyperoxia as well. While a cellular mechanism for the CO2 response has yet to be isolated, previous data show that a redox-sensitive mechanism underlies neuronal excitability to hyperoxia. However, it remains unknown how changes in Po2 affect the production of reactive oxygen and nitrogen species (RONS) in the cSC that can lead to increased cellular excitability and, with larger doses, to cellular dysfunction and death. To this end, we used fluorescence microscopy in real time to determine how normobaric hyperoxia increases the production of key RONS in the cSC. Because neurons in the region are CO2 sensitive, we also examined the potential effects of CO2 narcosis, used during euthanasia before brain slice harvesting, on RONS production. Our findings show that normobaric hyperoxia (0.4 → 0.95 atmospheres absolute O2) increases the fluorescence rates of fluorogenic dyes specific to both superoxide and nitric oxide. Interestingly, different results were seen for superoxide fluorescence when CO2 narcosis was used during euthanasia, suggesting long-lasting changes in superoxide production and/or antioxidant activity subsequent to CO2 narcosis before brain slicing. Further research needs to distinguish whether the increased levels of RONS reported here are merely increases in oxidative and nitrosative signaling or, alternatively, evidence of redox and nitrosative stress.
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Affiliation(s)
- Geoffrey E Ciarlone
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Jay B Dean
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, University of South Florida, Tampa, Florida
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23
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Majdi A, Mahmoudi J, Sadigh-Eteghad S, Golzari SE, Sabermarouf B, Reyhani-Rad S. Permissive role of cytosolic pH acidification in neurodegeneration: A closer look at its causes and consequences. J Neurosci Res 2016; 94:879-87. [DOI: 10.1002/jnr.23757] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Alireza Majdi
- Neurosciences Research Center; Tabriz University of Medical Sciences; Tabriz Iran
| | - Javad Mahmoudi
- Neurosciences Research Center; Tabriz University of Medical Sciences; Tabriz Iran
| | - Saeed Sadigh-Eteghad
- Neurosciences Research Center; Tabriz University of Medical Sciences; Tabriz Iran
| | - Samad E.J. Golzari
- Cardiovascular Research Center; Tabriz University of Medical Sciences; Tabriz Iran
| | - Babak Sabermarouf
- Neurosciences Research Center; Tabriz University of Medical Sciences; Tabriz Iran
| | - Siamak Reyhani-Rad
- Department of Laboratory Sciences; Marand Branch, Islamic Azad University; Marand Iran
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24
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Wajman JR, Bertolucci PHF, Mansur LL, Gauthier S. Culture as a variable in neuroscience and clinical neuropsychology: A comprehensive review. Dement Neuropsychol 2015; 9:203-218. [PMID: 29213964 PMCID: PMC5619361 DOI: 10.1590/1980-57642015dn93000002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/15/2015] [Indexed: 11/22/2022] Open
Abstract
Culture is a dynamic system of bidirectional influences among individuals and their environment, including psychological and biological processes, which facilitate adaptation and social interaction. One of the main challenges in clinical neuropsychology involves cognitive, behavioral and functional assessment of people with different sociocultural backgrounds. In this review essay, examining culture from a historical perspective to ethical issues in cross-cultural research, including the latest significant and publications, the authors sought to explore the main features related to cultural variables in neuropsychological practice and to debate the challenges found regarding the operational methods currently in use. Literature findings suggest a more comprehensive approach in cognitive and behavioral neuroscience, including an interface between elementary disciplines and applied neuropsychology. Thus, as a basis for discussion on this issue, the authors analyzed key-topics related to the study of new trends in sociocultural neuroscience and the application of their concepts from a clinical perspective.
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Affiliation(s)
- José Roberto Wajman
- Translational Neuroimaging Laboratory, McGill Centre for
Studies in Aging, Douglas Research Institute, McGill University, Montreal, QC,
Canada
- Behavioural Neurology Sector, Department of Neurology and
Neurosurgery, Federal University of São Paulo, São Paulo SP,
Brazil
- Behavioral and Cognitive Neurology Unit, Department of
Neurology, Hospital das Clínicas, University of São Paulo, São
Paulo SP, Brazil
| | | | - Letícia Lessa Mansur
- Behavioral and Cognitive Neurology Unit, Department of
Neurology, Hospital das Clínicas, University of São Paulo, São
Paulo SP, Brazil
- Department of Physiotherapy, Speech Pathology and
Occupational Therapy. Medical School, University of São Paulo, São
Paulo SP, Brazil
| | - Serge Gauthier
- Translational Neuroimaging Laboratory, McGill Centre for
Studies in Aging, Douglas Research Institute, McGill University, Montreal, QC,
Canada
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25
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Hartmann SE, Kissel CK, Szabo L, Walker BL, Leigh R, Anderson TJ, Poulin MJ. Increased ventilatory response to carbon dioxide in COPD patients following vitamin C administration. ERJ Open Res 2015; 1:00017-2015. [PMID: 27730137 PMCID: PMC5005137 DOI: 10.1183/23120541.00017-2015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/12/2015] [Indexed: 11/17/2022] Open
Abstract
Patients with chronic obstructive pulmonary disease (COPD) have decreased ventilatory and cerebrovascular responses to hypercapnia. Antioxidants increase the ventilatory response to hypercapnia in healthy humans. Cerebral blood flow is an important determinant of carbon dioxide/hydrogen ion concentration at the central chemoreceptors and may be affected by antioxidants. It is unknown whether antioxidants can improve the ventilatory and cerebral blood flow response in individuals in whom these are diminished. Thus, we aimed to determine the effect of vitamin C administration on the ventilatory and cerebrovascular responses to hypercapnia during healthy ageing and in COPD. Using transcranial Doppler ultrasound, we measured the ventilatory and cerebral blood flow responses to hyperoxic hypercapnia before and after an intravenous vitamin C infusion in healthy young (Younger) and older (Older) subjects and in moderate COPD. Vitamin C increased the ventilatory response in COPD patients (mean (95% CI) 1.1 (0.9-1.1) versus 1.5 (1.1-2.0) L·min-1·mmHg-1, p<0.05) but not in Younger (2.5 (1.9-3.1) versus 2.4 (1.9-2.9) L·min-1·mmHg-1, p>0.05) or Older (1.3 (1.0-1.7) versus 1.3 (1.0-1.7) L·min-1·mmHg-1, p>0.05) healthy subjects. Vitamin C did not affect the cerebral blood flow response in the young or older healthy subjects or COPD subjects (p>0.05). Vitamin C increases the ventilatory but not cerebrovascular response to hyperoxic hypercapnia in patients with moderate COPD.
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Affiliation(s)
- Sara E. Hartmann
- Dept of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Christine K. Kissel
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Dept of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - Lian Szabo
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Dept of Medicine, University of Calgary, Calgary, AB, Canada
| | - Brandie L. Walker
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Dept of Medicine, University of Calgary, Calgary, AB, Canada
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Richard Leigh
- Dept of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Dept of Medicine, University of Calgary, Calgary, AB, Canada
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Todd J. Anderson
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Dept of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
- Dept of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marc J. Poulin
- Dept of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
- Dept of Clinical Neuroscience, University of Calgary, Calgary, AB, Canada
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
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26
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Musa-Aziz R, Occhipinti R, Boron WF. Evidence from simultaneous intracellular- and surface-pH transients that carbonic anhydrase II enhances CO2 fluxes across Xenopus oocyte plasma membranes. Am J Physiol Cell Physiol 2014; 307:C791-813. [PMID: 24965587 DOI: 10.1152/ajpcell.00051.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The α-carbonic anhydrases (CAs) are zinc-containing enzymes that catalyze the interconversion of CO2 and HCO3 (-). Here, we focus on human CA II (CA II), a ubiquitous cytoplasmic enzyme. In the second paper in this series, we examine CA IV at the extracellular surface. After microinjecting recombinant CA II in a Tris solution (or just Tris) into oocytes, we expose oocytes to 1.5% CO2/10 mM HCO3 (-)/pH 7.50 while using microelectrodes to monitor intracellular pH (pHi) and surface pH (pHS). CO2 influx causes the familiar sustained pHi fall as well as a transient pHS rise; CO2 efflux does the opposite. Both during CO2 addition and removal, CA II increases the magnitudes of the maximal rate of pHi change, (dpHi/dt)max, and the maximal change in pHS, ΔpHS. Preincubating oocytes with the inhibitor ethoxzolamide eliminates the effects of CA II. Compared with pHS, pHi begins to change only after a delay of ~9 s and its relaxation has a larger (i.e., slower) time constant (τpHi > τpHS ). Simultaneous measurements with two pHi electrodes, one superficial and one deep, suggest that impalement depth contributes to pHi delay and higher τpHi . Using higher CO2/HCO3 (-) levels, i.e., 5%/33 mM HCO3 (-) or 10%/66 mM HCO3 (-), increases (dpHi/dt)max and ΔpHS, though not in proportion to the increase in [CO2]. A reaction-diffusion mathematical model (described in the third paper in this series) accounts for the above general features and supports the conclusion that cytosolic CA-consuming entering CO2 or replenishing exiting CO2-increases CO2 fluxes across the cell membrane.
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Affiliation(s)
- Raif Musa-Aziz
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut; and Department of Physiology and Biophysics, University of Sao Paulo, Institute of Biomedical Sciences, Sao Paulo, Brazil
| | - Rossana Occhipinti
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Walter F Boron
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio; Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut; and
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27
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Matott M, Ciarlone G, Putnam R, Dean J. Normobaric hyperoxia (95% O2) stimulates CO2-sensitive and CO2-insensitive neurons in the caudal solitary complex of rat medullary tissue slices maintained in 40% O2. Neuroscience 2014; 270:98-122. [DOI: 10.1016/j.neuroscience.2014.03.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 03/09/2014] [Accepted: 03/10/2014] [Indexed: 12/13/2022]
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28
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Substance P differentially modulates firing rate of solitary complex (SC) neurons from control and chronic hypoxia-adapted adult rats. PLoS One 2014; 9:e88161. [PMID: 24516602 PMCID: PMC3917864 DOI: 10.1371/journal.pone.0088161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 01/03/2014] [Indexed: 11/19/2022] Open
Abstract
NK1 receptors, which bind substance P, are present in the majority of brainstem regions that contain CO2/H(+)-sensitive neurons that play a role in central chemosensitivity. However, the effect of substance P on the chemosensitive response of neurons from these regions has not been studied. Hypoxia increases substance P release from peripheral afferents that terminate in the caudal nucleus tractus solitarius (NTS). Here we studied the effect of substance P on the chemosensitive responses of solitary complex (SC: NTS and dorsal motor nucleus) neurons from control and chronic hypoxia-adapted (CHx) adult rats. We simultaneously measured intracellular pH and electrical responses to hypercapnic acidosis in SC neurons from control and CHx adult rats using the blind whole cell patch clamp technique and fluorescence imaging microscopy. Substance P significantly increased the basal firing rate in SC neurons from control and CHx rats, although the increase was smaller in CHx rats. However, substance P did not affect the chemosensitive response of SC neurons from either group of rats. In conclusion, we found that substance P plays a role in modulating the basal firing rate of SC neurons but the magnitude of the effect is smaller for SC neurons from CHx adult rats, implying that NK1 receptors may be down regulated in CHx adult rats. Substance P does not appear to play a role in modulating the firing rate response to hypercapnic acidosis of SC neurons from either control or CHx adult rats.
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29
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Concepcion AR, Lopez M, Ardura-Fabregat A, Medina JF. Role of AE2 for pHi regulation in biliary epithelial cells. Front Physiol 2014; 4:413. [PMID: 24478713 PMCID: PMC3894451 DOI: 10.3389/fphys.2013.00413] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 12/27/2013] [Indexed: 12/31/2022] Open
Abstract
The Cl−/HCO−3anion exchanger 2 (AE2) is known to be involved in intracellular pH (pHi) regulation and transepithelial acid-base transport. Early studies showed that AE2 gene expression is reduced in liver biopsies and blood mononuclear cells from patients with primary biliary cirrhosis (PBC), a disease characterized by chronic non-suppurative cholangitis associated with antimitochondrial antibodies (AMA) and other autoimmune phenomena. Microfluorimetric analysis of the Cl−/HCO−3 anion exchange (AE) in isolated cholangiocytes showed that the cAMP-stimulated AE activity is diminished in PBC compared to both healthy and diseased controls. More recently, it was found that miR-506 is upregulated in cholangiocytes of PBC patients and that AE2 may be a target of miR-506. Additional evidence for a pathogenic role of AE2 dysregulation in PBC was obtained with Ae2−/−a,b mice, which develop biochemical, histological, and immunologic alterations that resemble PBC (including development of serum AMA). Analysis of HCO−3 transport systems and pHi regulation in cholangiocytes from normal and Ae2−/−a,b mice confirmed that AE2 is the transporter responsible for the Cl−/HCO−3exchange in these cells. On the other hand, both Ae2+/+a,b and Ae2−/−a,b mouse cholangiocytes exhibited a Cl−-independent bicarbonate transport system, essentially a Na+-bicarbonate cotransport (NBC) system, which could contribute to pHi regulation in the absence of AE2.
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Affiliation(s)
- Axel R Concepcion
- Division of Gene Therapy and Hepatology, Center for Applied Medical Research (CIMA), School of Medicine, University of Navarra, and Ciberehd Pamplona, Spain
| | - María Lopez
- Division of Gene Therapy and Hepatology, Center for Applied Medical Research (CIMA), School of Medicine, University of Navarra, and Ciberehd Pamplona, Spain
| | - Alberto Ardura-Fabregat
- Division of Gene Therapy and Hepatology, Center for Applied Medical Research (CIMA), School of Medicine, University of Navarra, and Ciberehd Pamplona, Spain
| | - Juan F Medina
- Division of Gene Therapy and Hepatology, Center for Applied Medical Research (CIMA), School of Medicine, University of Navarra, and Ciberehd Pamplona, Spain
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30
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Stuth EAE, Stucke AG, Zuperku EJ. Effects of anesthetics, sedatives, and opioids on ventilatory control. Compr Physiol 2013; 2:2281-367. [PMID: 23720250 DOI: 10.1002/cphy.c100061] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This article provides a comprehensive, up to date summary of the effects of volatile, gaseous, and intravenous anesthetics and opioid agonists on ventilatory control. Emphasis is placed on data from human studies. Further mechanistic insights are provided by in vivo and in vitro data from other mammalian species. The focus is on the effects of clinically relevant agonist concentrations and studies using pharmacological, that is, supraclinical agonist concentrations are de-emphasized or excluded.
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Affiliation(s)
- Eckehard A E Stuth
- Medical College of Wisconsin, Anesthesia Research Service, Zablocki VA Medical Center, Milwaukee, Wisconsin, USA.
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31
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Culcasi M, Casano G, Lucchesi C, Mercier A, Clément JL, Pique V, Michelet L, Krieger-Liszkay A, Robin M, Pietri S. Synthesis and Biological Characterization of New Aminophosphonates for Mitochondrial pH Determination by 31P NMR Spectroscopy. J Med Chem 2013; 56:2487-99. [DOI: 10.1021/jm301866e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Marcel Culcasi
- Aix-Marseille Université, CNRS UMR 7273, Equipe Sondes Moléculaires en Biologie et
Stress Oxydant, Institut de Chimie Radicalaire, Marseille, France
| | - Gilles Casano
- Aix-Marseille Université, CNRS UMR 7273, Equipe Sondes Moléculaires en Biologie et
Stress Oxydant, Institut de Chimie Radicalaire, Marseille, France
| | - Céline Lucchesi
- Aix-Marseille Université, CNRS UMR 7273, Equipe Sondes Moléculaires en Biologie et
Stress Oxydant, Institut de Chimie Radicalaire, Marseille, France
| | - Anne Mercier
- Aix-Marseille Université, CNRS UMR 7273, Equipe Sondes Moléculaires en Biologie et
Stress Oxydant, Institut de Chimie Radicalaire, Marseille, France
| | - Jean-Louis Clément
- Aix-Marseille Université, CNRS UMR 7273, Equipe Sondes Moléculaires en Biologie et
Stress Oxydant, Institut de Chimie Radicalaire, Marseille, France
| | - Valérie Pique
- Aix-Marseille Université, CNRS UMR 7273, Equipe Sondes Moléculaires en Biologie et
Stress Oxydant, Institut de Chimie Radicalaire, Marseille, France
| | - Laure Michelet
- CNRS UMR 8221, Institut de Biologie et de Technologie de Saclay (iBiTec-S),
CEA Saclay, Gif-sur-Yvette, France
| | - Anja Krieger-Liszkay
- CNRS UMR 8221, Institut de Biologie et de Technologie de Saclay (iBiTec-S),
CEA Saclay, Gif-sur-Yvette, France
| | - Maxime Robin
- Aix-Marseille Université, CNRS UMR 7273, Equipe Sondes Moléculaires en Biologie et
Stress Oxydant, Institut de Chimie Radicalaire, Marseille, France
| | - Sylvia Pietri
- Aix-Marseille Université, CNRS UMR 7273, Equipe Sondes Moléculaires en Biologie et
Stress Oxydant, Institut de Chimie Radicalaire, Marseille, France
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Pilla R, Landon CS, Dean JB. A potential early physiological marker for CNS oxygen toxicity: hyperoxic hyperpnea precedes seizure in unanesthetized rats breathing hyperbaric oxygen. J Appl Physiol (1985) 2013; 114:1009-20. [PMID: 23429869 DOI: 10.1152/japplphysiol.01326.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Hyperbaric oxygen (HBO(2)) stimulates presumptive central CO2-chemoreceptor neurons, increases minute ventilation (V(min)), decreases heart rate (HR) and, if breathed sufficiently long, produces central nervous system oxygen toxicity (CNS-OT; i.e., seizures). The risk of seizures when breathing HBO(2) is variable between individuals and its onset is difficult to predict. We have tested the hypothesis that a predictable pattern of cardiorespiration precedes an impending seizure when breathing HBO2. To test this hypothesis, 27 adult male Sprague-Dawley rats were implanted with radiotelemetry transmitters to assess diaphragmatic/abdominal electromyogram, electrocardiogram, and electroencephalogram. Seven days after surgery, each rat was placed in a sealed, continuously ventilated animal chamber inside a hyperbaric chamber. Both chambers were pressurized in parallel using poikilocapnic 100% O(2) (animal chamber) and air (hyperbaric chamber) to 4, 5, or 6 atmospheres absolute (ATA). Breathing 1 ATA O(2) initially decreased V(min) and HR (Phase 1 of the compound hyperoxic ventilatory response). With continued exposure to normobaric hyperoxia, however, V(min) began increasing toward the end of exposure in one-third of the animals tested. Breathing HBO2 induced an early transient increase in V(min) (Phase 2) and HR during the chamber pressurization, followed by a second significant increase of V(min) ≤8 min prior to seizure (Phase 3). HR, which subsequently decreased during sustained hyperoxia, showed no additional changes prior to seizure. We conclude that hyperoxic hyperpnea (Phase 3 of the compound hyperoxic ventilatory response) is a predictor of an impending seizure while breathing poikilocapnic HBO(2) at rest in unanesthetized rats.
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Affiliation(s)
- Raffaele Pilla
- Department of Molecular Pharmacology & Physiology, Hyperbaric Biomedical Research Laboratory, University of South Florida, Morsani College of Medicine, Tampa, FL 33612, USA
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Catts VS, Weickert CS. Gene expression analysis implicates a death receptor pathway in schizophrenia pathology. PLoS One 2012; 7:e35511. [PMID: 22545112 PMCID: PMC3335850 DOI: 10.1371/journal.pone.0035511] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 03/16/2012] [Indexed: 12/22/2022] Open
Abstract
An increase in apoptotic events may underlie neuropathology in schizophrenia. By data-mining approaches, we identified significant expression changes in death receptor signaling pathways in the dorsolateral prefrontal cortex (DLPFC) of patients with schizophrenia, particularly implicating the Tumor Necrosis Factor Superfamily member 6 (FAS) receptor and the Tumor Necrosis Factor [ligand] Superfamily member 13 (TNFSF13) in schizophrenia. We sought to confirm and replicate in an independent tissue collection the noted mRNA changes with quantitative real-time RT-PCR. To test for regional and diagnostic specificity, tissue from orbital frontal cortex (OFC) was examined and a bipolar disorder group included. In schizophrenia, we confirmed and replicated significantly increased expression of TNFSF13 mRNA in the DLPFC. Also, a significantly larger proportion of subjects in the schizophrenia group had elevated FAS receptor expression in the DLPFC relative to unaffected controls. These changes were not observed in the bipolar disorder group. In the OFC, there were no significant differences in TNFSF13 or FAS receptor mRNA expression. Decreases in BH3 interacting domain death agonist (BID) mRNA transcript levels were found in the schizophrenia and bipolar disorder groups affecting both the DLPFC and the OFC. We tested if TNFSF13 mRNA expression correlated with neuronal mRNAs in the DLPFC, and found significant negative correlations with interneuron markers, parvalbumin and somatostatin, and a positive correlation with PPP1R9B (spinophilin), but not DLG4 (PSD-95). The expression of TNFSF13 mRNA in DLPFC correlated negatively with tissue pH, but decreasing pH in cultured cells did not cause increased TNFSF13 mRNA nor did exogenous TNFSF13 decrease pH. We concluded that increased TNFSF13 expression may be one of several cell-death cytokine abnormalities that contribute to the observed brain pathology in schizophrenia, and while increased TNFSF13 may be associated with lower brain pH, the change is not necessarily causally related to brain pH.
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Affiliation(s)
- Vibeke Sørensen Catts
- Schizophrenia Research Laboratory, Schizophrenia Research Institute, Sydney, New South Wales, Australia.
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Wan J, Forsyth AM, Stone HA. Red blood cell dynamics: from cell deformation to ATP release. Integr Biol (Camb) 2011; 3:972-81. [PMID: 21935538 DOI: 10.1039/c1ib00044f] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The mechanisms of red blood cell (RBC) deformation under both static and dynamic, i.e., flow, conditions have been studied extensively since the mid 1960s. Deformation-induced biochemical reactions and possible signaling in RBCs, however, were proposed only fifteen years ago. Therefore, the fundamental relationship between RBC deformation and cellular signaling dynamics i.e., mechanotransduction, remains incompletely understood. Quantitative understanding of the mechanotransductive pathways in RBCs requires integrative studies of physical models of RBC deformation and cellular biochemical reactions. In this article we review the physical models of RBC deformation, spanning from continuum membrane mechanics to cellular skeleton dynamics under both static and flow conditions, and elaborate the mechanistic links involved in deformation-induced ATP release.
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Affiliation(s)
- Jiandi Wan
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, USA
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35
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Theory of gastric CO2 ventilation and its control during respiratory acidosis: Implications for central chemosensitivity, pH regulation, and diseases causing chronic CO2 retention. Respir Physiol Neurobiol 2011; 175:189-209. [DOI: 10.1016/j.resp.2010.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 12/01/2010] [Accepted: 12/01/2010] [Indexed: 01/16/2023]
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36
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Lin JL, Thomas PS. Current perspectives of oxidative stress and its measurement in chronic obstructive pulmonary disease. COPD 2010; 7:291-306. [PMID: 20673039 DOI: 10.3109/15412555.2010.496818] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cigarette smoking, the principal aetiology of chronic obstructive pulmonary disease (COPD) in the developed countries, delivers and generates oxidative stress within the lungs. This imbalance of oxidant burden and antioxidant capacity has been implicated as an important contributing factor in the pathogenesis of COPD. Oxidative processes and free radical generation orchestrate the inflammation, mucous gland hyperplasia, and apoptosis of the airway lining epithelium which characterises COPD. Pivotal oxidative stress/pro-inflammatory molecules include reactive oxygen species such as the superoxides and hydroxyl radicals, pro-inflammatory cytokines including leukotrienes, interleukins, tumour necrosis factor alpha, and activated transcriptional factors such as nuclear factor kappa-B and activator protein 1. The lung has a large reserve of antioxidant agents such as glutathione and superoxide dismutase to counter oxidants. However, smoking also causes the depletion of antioxidants, which further contributes to oxidative tissue damage. The downregulation of antioxidant pathways has also been associated with acute exacerbations of COPD. The delivery of redox-protective antioxidants may have preventative and therapeutic potential of COPD. Although these observations have yet to translate into common clinical practice, preliminary clinical trials and studies of animal models have shown that interventions to counter this oxidative imbalance may have potential to better manage COPD. There is, thus, a need for the ability to monitor such interventions and exhaled breath condensate is rapidly emerging as a novel and noninvasive approach in the sampling of airway epithelial lining fluid which could be used for repeated analysis of oxidative stress and inflammation in the lungs.
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Affiliation(s)
- Jiun-Lih Lin
- University of New South Wales, Sydney, Australia.
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37
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Chowdhuri S, Sinha P, Pranathiageswaran S, Badr MS. Sustained hyperoxia stabilizes breathing in healthy individuals during NREM sleep. J Appl Physiol (1985) 2010; 109:1378-83. [PMID: 20724559 PMCID: PMC2980383 DOI: 10.1152/japplphysiol.00453.2010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 08/18/2010] [Indexed: 11/22/2022] Open
Abstract
The present study was designed to determine whether hyperoxia would lower the hypocapnic apneic threshold (AT) during non-rapid eye movement (NREM) sleep. Nasal noninvasive mechanical ventilation was used to induce hypocapnia and subsequent central apnea in healthy subjects during stable NREM sleep. Mechanical ventilation trials were conducted under normoxic (room air) and hyperoxic conditions (inspired PO(2) > 250 Torr) in a random order. The CO(2) reserve was defined as the minimal change in end-tidal PCO(2) (PET(CO(2))) between eupnea and hypocapnic central apnea. The PET(CO(2)) of the apnea closest to eupnea was designated as the AT. The hypocapnic ventilatory response was calculated as the change in ventilation below eupnea for a given change in PET(CO(2)). In nine participants, compared with room air, exposure to hyperoxia was associated with a significant decrease in eupneic PET(CO(2)) (37.5 ± 0.6 vs. 41.1 ± 0.6 Torr, P = 0.001), widening of the CO(2) reserve (-3.8 ± 0.8 vs. -2.0 ± 0.3 Torr, P = 0.03), and a subsequent decline in AT (33.3 ± 1.2 vs. 39.0 ± 0.7 Torr; P = 001). The hypocapnic ventilatory response was also decreased with hyperoxia. In conclusion, 1) hyperoxia was associated with a decreased AT and an increase in the magnitude of hypocapnia required for the development of central apnea. 2) Thus hyperoxia may mitigate the effects of hypocapnia on ventilatory motor output by lowering the hypocapnic ventilatory response and lowering the resting eupneic PET(CO(2)), thereby decreasing plant gain.
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Affiliation(s)
- Susmita Chowdhuri
- Medical Service, John D. Dingell Veterans Affairs Medical Center, Detroit, MI 48201, USA.
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38
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Dean JB, Putnam RW. The caudal solitary complex is a site of central CO(2) chemoreception and integration of multiple systems that regulate expired CO(2). Respir Physiol Neurobiol 2010; 173:274-87. [PMID: 20670695 DOI: 10.1016/j.resp.2010.07.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 06/30/2010] [Accepted: 07/01/2010] [Indexed: 12/16/2022]
Abstract
The solitary complex is comprised of the nucleus tractus solitarius (NTS, sensory) and dorsal motor nucleus of the vagus (DMV, motor), which functions as an integrative center for neural control of multiple systems including the respiratory, cardiovascular and gastroesophageal systems. The caudal NTS-DMV is one of the several sites of central CO(2) chemoreception in the brain stem. CO(2) chemosensitive neurons are fully responsive to CO(2) at birth and their responsiveness seems to depend on pH-sensitive K(+) channels. In addition, chemosensitive neurons are highly sensitive to conditions such as hypoxia (e.g., neural plasticity) and hyperoxia (e.g., stimulation), suggesting they employ redox and nitrosative signaling mechanisms. Here we review the cellular and systems physiological evidence supporting our hypothesis that the caudal NTS-DMV is a site for integration of respiratory, cardiovascular and gastroesophageal systems that work together to eliminate CO(2) during acute and chronic respiratory acidosis to restore pH homeostasis.
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Affiliation(s)
- Jay B Dean
- Dept. of Molecular Pharmacology & Physiology, Hyperbaric Biomedical Research Laboratory, University of South Florida, Tampa, FL 33612, USA.
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Bavis RW, Young KM, Barry KJ, Boller MR, Kim E, Klein PM, Ovrutsky AR, Rampersad DA. Chronic hyperoxia alters the early and late phases of the hypoxic ventilatory response in neonatal rats. J Appl Physiol (1985) 2010; 109:796-803. [PMID: 20576840 DOI: 10.1152/japplphysiol.00510.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chronic hyperoxia during the first 1-4 postnatal weeks attenuates the hypoxic ventilatory response (HVR) subsequently measured in adult rats. Rather than focusing on this long-lasting plasticity, the present study considered the influence of hyperoxia on respiratory control during the neonatal period. Sprague-Dawley rats were born and raised in 60% O2 until studied at postnatal ages (P) of 4, 6-7, or 13-14 days. Ventilation and metabolism were measured in normoxia (21% O2) and acute hypoxia (12% O2) using head-body plethysmography and respirometry, respectively. Compared with age-matched rats raised in room air, the major findings were 1) diminished pulmonary ventilation and metabolic O2 consumption in normoxia at P4 and P6-7; 2) decreased breathing stability during normoxia; 3) attenuation of the early phase of the HVR at P6-7 and P13-14; and 4) a sustained increase in ventilation during hypoxia (vs. the normal biphasic HVR) at all ages studied. Attenuation of the early HVR likely reflects progressive impairment of peripheral arterial chemoreceptors while expression of a sustained HVR in neonates before P7 suggests that hyperoxia also induces plasticity within the central nervous system. Together, these results suggest a complex interaction between inhibitory and excitatory effects of hyperoxia on the developing respiratory control system.
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Affiliation(s)
- Ryan W Bavis
- Department of Biology, Bates College, 44 Campus Ave., Carnegie Science Hall, Lewiston, ME 04240, USA.
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40
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Dean JB. Hypercapnia causes cellular oxidation and nitrosation in addition to acidosis: implications for CO2 chemoreceptor function and dysfunction. J Appl Physiol (1985) 2010; 108:1786-95. [PMID: 20150563 PMCID: PMC2886689 DOI: 10.1152/japplphysiol.01337.2009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 02/08/2010] [Indexed: 12/22/2022] Open
Abstract
Cellular mechanisms of CO2 chemoreception are discussed and debated in terms of the stimuli produced during hypercapnic acidosis and their molecular targets: protons generated by the hydration of CO2 and dissociation of carbonic acid, which target membrane-bound proteins and lipids in brain stem neurons. The CO2 hydration reaction, however, is not the only reaction that CO2 undergoes that generates molecules capable of modifying proteins and lipids. Molecular CO2 also reacts with peroxynitrite (ONOO-), a reactive nitrogen species (RNS), which is produced from nitric oxide (*NO) and superoxide (*O2-). The CO2/ONOO- reaction, in turn, produces additional nitrosative and oxidative reactive intermediates. Furthermore, protons facilitate additional redox reactions that generate other reactive oxygen species (ROS). ROS/RNS generated by these redox reactions may act as additional stimuli of CO2 chemoreceptors since neurons in chemosensitive areas produce both *NO and *O2- and, therefore, ONOO-. Perturbing *NO, *O2-, and ONOO- activities in chemosensitive areas modulates cardiorespiration. Moreover, neurons in at least one chemosensitive area, the solitary complex, are stimulated by cellular oxidation. Together, these data raise the following two questions: 1) do pH and ROS/RNS work in tandem to stimulate CO2 chemoreceptors during hypercapnic acidosis; and 2) does nitrosative stress and oxidative stress contribute to CO2 chemoreceptor dysfunction? To begin considering these two issues and their implications for central chemoreception, this minireview has the following three goals: 1) summarize the nitrosative and oxidative reactions that occur during hypercapnic acidosis and isocapnic acidosis; 2) review the evidence that redox signaling occurs in chemosensitive areas; and 3) review the evidence that neurons in the solitary complex are stimulated by cellular oxidation.
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Affiliation(s)
- Jay B Dean
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, University of South Florida, College of Medicine, MDC 8, 12901 Bruce B. Downs Blvd., Tampa, Florida 33612, USA.
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Nichols NL, Wilkinson KA, Powell FL, Dean JB, Putnam RW. Chronic hypoxia suppresses the CO2 response of solitary complex (SC) neurons from rats. Respir Physiol Neurobiol 2009; 168:272-80. [PMID: 19619674 DOI: 10.1016/j.resp.2009.07.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2008] [Revised: 07/12/2009] [Accepted: 07/13/2009] [Indexed: 11/17/2022]
Abstract
We studied the effect of chronic hypobaric hypoxia (CHx; 10-11% O(2)) on the response to hypercapnia (15% CO(2)) of individual solitary complex (SC) neurons from adult rats. We simultaneously measured the intracellular pH and firing rate responses to hypercapnia of SC neurons in superfused medullary slices from control and CHx-adapted adult rats using the blind whole cell patch clamp technique and fluorescence imaging microscopy. We found that CHx caused the percentage of SC neurons inhibited by hypercapnia to significantly increase from about 10% up to about 30%, but did not significantly alter the percentage of SC neurons activated by hypercapnia (50% in control vs. 35% in CHx). Further, the magnitudes of the responses of SC neurons from control rats (chemosensitivity index for activated neurons of 166+/-11% and for inhibited neurons of 45+/-15%) were the same in SC neurons from CHx-adapted rats. This plasticity induced in chemosensitive SC neurons by CHx appears to involve intrinsic changes in neuronal properties since they were the same in synaptic blockade medium.
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Affiliation(s)
- Nicole L Nichols
- Department of Neuroscience, Cell Biology & Physiology, Wright State University Boonshoft School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA
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Misiti F, Orsini F, Clementi ME, Masala D, Tellone E, Galtieri A, Giardina B. Amyloid peptide inhibits ATP release from human erythrocytes. Biochem Cell Biol 2009; 86:501-8. [PMID: 19088798 DOI: 10.1139/o08-139] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The oxygen required to meet metabolic needs of all tissues is delivered by the erythrocyte, a small, flexible cell, which, in mammals, is devoid of a nucleus and mitochondria. Despite its simple appearance, this cell has an important role in its own distribution, enabling the delivery of oxygen to precisely meet localized metabolic need. When an erythrocyte enters in a hypoxic area, a signalling pathway is activated within the cell resulting in the release of ATP in amounts adequate to activate purinergic receptors on vascular endothelium, which trigger secretion of nitric oxide and other factors resulting in vasodilatation. Among other mechanisms, binding of deoxyhemoglobin to the cytoplasmic domain of the anion-exchange protein band 3 is probably involved in this pathway. The present study investigates the effect of amyloid beta peptide exposure on this molecular mechanism. We report that deoxygenated human erythrocytes fail to release ATP following 24 h exposure to amyloid beta peptide. Concurrently, amyloid beta peptide induces caspase 3 activation. Preincubation of amyloid beta peptide treated erythrocytes with a specific inhibitor of caspase 3 prevents amyloid-induced caspase 3 activation and restores the erythrocyte's ability to release ATP under deoxygenated conditions. Since the activity of red cell phosphofructokinase, a key step in glycolytic flux, is not modified within the red cell following amyloid peptide exposure, it is likely that ATP release reduction is not dependent on glycolytic flux alterations. It has also been suggested that the heterotrimeric G protein, Gi, and adenylyl cyclase are downstream critical components of the pathway responsible for ATP release. We show that cAMP synthesis and ATP release are not failed in amyloid-peptide-treated erythrocytes in response to incubation with mastoparan 7 or forskolin plus 3-isobutyl-1-methyl xanthine, agents that stimulate cAMP synthesis. In conclusion, these results indicate that amyloid beta peptide inhibits ATP release from deoxygenated erythrocytes by activating red cell caspase 3, suggesting a pathophysiologic role for vascular amyloid peptide in Alzheimer's disease.
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Affiliation(s)
- Francesco Misiti
- Department of Health and Motor Sciences, University of Cassino, V.le Bonomi 03043, Cassino (FR), Italy.
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43
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Conrad SC, Nichols NL, Ritucci NA, Dean JB, Putnam RW. Development of chemosensitivity in neurons from the nucleus tractus solitarii (NTS) of neonatal rats. Respir Physiol Neurobiol 2009; 166:4-12. [PMID: 19056522 PMCID: PMC2683148 DOI: 10.1016/j.resp.2008.11.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 11/07/2008] [Accepted: 11/07/2008] [Indexed: 11/16/2022]
Abstract
We studied the development of chemosensitivity during the neonatal period in rat nucleus tractus solitarii (NTS) neurons. We determined the percentage of neurons activated by hypercapnia (15% CO(2)) and assessed the magnitude of the response by calculating the chemosensitivity index (CI). There were no differences in the percentage of neurons that were inhibited (9%) or activated (44.8%) by hypercapnia or in the magnitude of the activated response (CI 164+/-4.9%) in NTS neurons from neonatal rats of all ages. To assess the degree of intrinsic chemosensitivity in these neurons we used chemical synaptic block medium and the gap junction blocker carbenoxolone. Chemical synaptic block medium slightly decreased basal firing rate but did not affect the percentage of NTS neurons that responded to hypercapnia at any neonatal age. However, in neonates aged
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Affiliation(s)
- Susan C. Conrad
- Department of Neuroscience, Cell Biology and Physiology, Wright State University School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435
| | - Nicole L. Nichols
- Department of Neuroscience, Cell Biology and Physiology, Wright State University School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435
| | - Nick A. Ritucci
- Department of Neuroscience, Cell Biology and Physiology, Wright State University School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435
| | - Jay B. Dean
- Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, 12901 Bruce B. Downs Boulevard, Tampa, FL 33612
| | - Robert W. Putnam
- Department of Neuroscience, Cell Biology and Physiology, Wright State University School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435
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44
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Nichols NL, Mulkey DK, Wilkinson KA, Powell FL, Dean JB, Putnam RW. Characterization of the chemosensitive response of individual solitary complex neurons from adult rats. Am J Physiol Regul Integr Comp Physiol 2009; 296:R763-73. [PMID: 19144749 DOI: 10.1152/ajpregu.90769.2008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We studied the CO(2)/H(+)-chemosensitive responses of individual solitary complex (SC) neurons from adult rats by simultaneously measuring the intracellular pH (pH(i)) and electrical responses to hypercapnic acidosis (HA). SC neurons were recorded using the blind whole cell patch-clamp technique and loading the soma with the pH-sensitive dye pyranine through the patch pipette. We found that SC neurons from adult rats have a lower steady-state pH(i) than SC neurons from neonatal rats. In the presence of chemical and electrical synaptic blockade, adult SC neurons have firing rate responses to HA (percentage of neurons activated or inhibited and the magnitude of response as determined by the chemosensitivity index) that are similar to SC neurons from neonatal rats. They also have a typical response to isohydric hypercapnia, including decreased DeltapH(i), followed by pH(i) recovery, and increased firing rate. Thus, the chemosensitive response of SC neurons from adults is similar to the chemosensitive response of SC neurons from neonatal rats. Because our findings for adults are similar to previously reported values for neurons from neonatal rats, we conclude that intrinsic chemosensitivity is established early in development for SC neurons and is maintained throughout adulthood.
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Affiliation(s)
- Nicole L Nichols
- Dept. of Neuroscience, Cell Biology and Physiology, Wright State Univ., Boonshoft School of Medicine, Dayton, OH 45435, USA
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45
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Ariyama Y, Tanaka Y, Shimizu H, Shimomura K, Okada S, Saito T, Yamada E, Oyadomari S, Mori M, Mori M. The role of CHOP messenger RNA expression in the link between oxidative stress and apoptosis. Metabolism 2008; 57:1625-35. [PMID: 19013284 DOI: 10.1016/j.metabol.2008.06.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Accepted: 06/09/2008] [Indexed: 12/20/2022]
Abstract
Low expression of antioxidant enzymes makes pancreatic beta-cells susceptible to cell damage by oxidative stress. Pancreatic beta-cell loss caused by endoplasmic reticulum stress is associated with the onset of diabetes mellitus. The present studies were undertaken to investigate a possible involvement of proapoptotic gene CHOP in pancreatic beta-cells damage by oxidative stress. The induction of CHOP messenger RNA and apoptosis were investigated in betaHC-9 cells after the oxidative stress by hydrogen peroxide and ribose. Latter was examined after the suppression of CHOP by small interfering RNA. For in vivo study, the pancreatic beta-cells were examined in CHOP-knockout (KO) mice after multiple low-dose streptozotocin (MLDS) administration. In betaHC-9 cells, both hydrogen peroxide and ribose obviously increased apoptotic cells, accompanied with enhanced CHOP messenger RNA expression. However, the number of apoptotic cells by those stimulations was significantly reduced by the addition of small interfering RNA against CHOP. In vivo study also showed that CHOP-KO mice were less susceptible to diabetes after MLDS administration. Although the oxidative stress marker level was similar to that of MLDS-treated wild type, the pancreatic beta-cell area was maintained in CHOP-KO mice. The present studies showed that CHOP should be important in pancreatic beta-cell injury by oxidative stress and indicate that CHOP may play a role in the development of pancreatic beta-cell damage on the onset of diabetes mellitus.
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Affiliation(s)
- Yasuyo Ariyama
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
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46
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Johnson SM, Haxhiu MA, Richerson GB. GFP-expressing locus ceruleus neurons from Prp57 transgenic mice exhibit CO2/H+ responses in primary cell culture. J Appl Physiol (1985) 2008; 105:1301-11. [PMID: 18635881 PMCID: PMC2576037 DOI: 10.1152/japplphysiol.90414.2008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Accepted: 07/12/2008] [Indexed: 11/22/2022] Open
Abstract
The locus ceruleus (LC) contains neurons that increase their firing rate (FR) in vitro when exposed to elevated CO(2)/H(+) and have been proposed to influence the respiratory network to make compensatory adjustments in ventilation. Prp57 transgenic mice express green fluorescent protein (GFP) in the LC and were used to isolate, culture, and target LC neurons for electrophysiological recording. We hypothesized that GFP-LC neurons would exhibit CO(2)/H(+) chemosensitivity under primary culture conditions, evidenced as a change in FR. This is the first study to quantify CO(2)/H(+) responses in LC neuron FR in cell culture. Neurons were continuously bathed with solutions containing antagonists of glutamate and GABA receptors, and the acid-base status was changed from control (5% CO(2); pH approximately 7.4) to hypercapnic acidosis (9% CO(2); pH approximately 7.2) and hypocapnic alkalosis (3% CO(2); pH approximately 7.6). FR was quantified during perforated patch current clamp recordings. Approximately 86% of GFP-LC neurons were stimulated, and approximately 14% were insensitive to changes in CO(2)/H(+). The magnitude of the response of these neurons depended on the baseline FR, ranging from 155.9 +/- 6% when FR started at 2.95 +/- 0.49 Hz to 381 +/- 55.6% when FR started at 1.32 +/- 0.31 Hz. These results demonstrate that cultured LC neurons from Prp57 transgenic mice retain functional sensing molecules necessary for CO(2)/H(+) responses. Prp57 transgenic mice will serve as a valuable model to delineate mechanisms involved in CO(2)/H(+) responsiveness in catecholaminergic neurons.
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Affiliation(s)
- Shereé M Johnson
- Department of Physiology and Biophysics, Howard University College of Medicine, 520 W Street Northwest, Washington, DC 20059, USA.
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Rocha MA, Crockett DP, Wong LY, Richardson JR, Sonsalla PK. Na(+)/H(+) exchanger inhibition modifies dopamine neurotransmission during normal and metabolic stress conditions. J Neurochem 2008; 106:231-43. [PMID: 18363831 DOI: 10.1111/j.1471-4159.2008.05355.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Na(+)/H(+) exchanger (NHE) proteins are involved in intracellular pH and volume regulation and may indirectly influence neurotransmission. The abundant NHE isoform 1 (NHE1) has also been linked to brain cell damage during metabolic stress. It is not known, however, whether NHE1 or other NHE isoforms play a role in striatal dopamine (DA) neurotransmission under normal or metabolic stress conditions. Our study tested the hypothesis that NHE inhibition with cariporide mesilate (HOE-642) modifies striatal DA overflow and DAergic terminal damage in mice caused by the mitochondrial inhibitor malonate. We also explored the expression of NHE1-5 in the striatum and substantia nigra. Reverse microdialysis of HOE-642 elicited a transient elevation followed by a reduction in DA overflow accompanied by a decline in striatal DA content. HOE-642 pre-treatment diminished the malonate-induced DA overflow without reducing the intensity of the metabolic stress or subsequent DAergic axonal damage. Although NHE isoforms 1-5 are expressed in the striatum and midbrain, NHE1 protein was not co-located on nigrostriatal DAergic neurons. The absence of NHE1 co-location on DAergic neurons suggests that the effects of HOE-642 on striatal DA overflow are either mediated via NHE1 located on other cell types or that HOE-642 is acting through multiple NHE isoforms.
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Affiliation(s)
- Marcelo A Rocha
- Department of Neurology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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48
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Aging-related changes in the sensitivity of the system of respiratory control and the intensity of free-radical processes in humans. NEUROPHYSIOLOGY+ 2008. [DOI: 10.1007/s11062-008-9017-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Obara M, Szeliga M, Albrecht J. Regulation of pH in the mammalian central nervous system under normal and pathological conditions: facts and hypotheses. Neurochem Int 2007; 52:905-19. [PMID: 18061308 DOI: 10.1016/j.neuint.2007.10.015] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 10/17/2007] [Accepted: 10/22/2007] [Indexed: 11/27/2022]
Abstract
The maintenance of pH homeostasis in the CNS is of key importance for proper execution and regulation of neurotransmission, and deviations from this homeostasis are a crucial factor in the mechanism underlying a spectrum of pathological conditions. The first few sections of the review are devoted to the brain operating under normal conditions. The article commences with an overview of how extrinsic factors modelling the brain at work: neurotransmitters, depolarising stimuli (potassium and voltage changes) and cyclic nucleotides as major signal transducing vehicles affect pH in the CNS. Further, consequences of pH alterations on the major aspects of CNS function and metabolism are outlined. Next, the major cellular events involved in the transport, sequestration, metabolic production and buffering of protons that are common to all the mammalian cells, including the CNS cells. Since CNS function reflects tight interaction between astrocytes and neurons, the pH regulatory events pertinent to either cell type are discussed: overwhelming evidence implicates astrocytes as a key player in pH homeostasis in the brain. The different classes of membrane proteins involved in proton shuttling are listed and their mechanisms of action are given. These include: the Na+/H+ exchanger, different classes of bicarbonate transporters acting in a sodium-dependent- or -independent mode, monocarboxylic acid transporters and the vacuolar-type proton ATPase. A separate section is devoted to carbonic anhydrase, which is represented by multiple isoenzymes capable of pH buffering both in the cell interior and in the extracellular space. Next, impairment of pH regulation and compensatory responses occurring in brain affected by different pathologies: hypoxia/ischemia, epilepsy, hyperammonemic encephalopathies, cerebral tumours and HIV will be described. The review is limited to facts and plausible hypotheses pertaining to phenomena directly involved in pH regulation: changes in pH that accompany metabolic stress but have no distinct implications for the pH regulatory mechanisms are not dealt with. In most cases, the vast body of knowledge derived from in vitro studies remains to be verified in in vivo settings.
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Affiliation(s)
- Marta Obara
- Department of Neurotoxicology, Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego Street, 02-106 Warsaw, Poland
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Sprague R, Stephenson A, Bowles E, Stumpf M, Ricketts G, Lonigro A. Expression of the heterotrimeric G protein Gi and ATP release are impaired in erythrocytes of humans with diabetes mellitus. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 588:207-16. [PMID: 17089891 DOI: 10.1007/978-0-387-34817-9_18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Erythrocytes of humans have been reported to stimulate nitric oxide (NO) synthesis in the circulation as a consequence of their ability to release ATP in response to both mechanical deformation and exposure to reduced oxygen tension. It has been proposed that the ability of the erythrocyte to affect local vascular resistance permits it to participate in the regulation of blood flow such that oxygen delivery is matched with metabolic need. A signal transduction pathway that relates deformation and exposure to reduced oxygen tension to ATP release from human erythrocytes has been described. The heterotrimeric G protein, Gi, is a critical component of this pathway. Importantly, stimulation of Gi results in activation of adenylyl cyclase and ATP release from these cells. Recently, in a model of diabetes mellitus in rats, expression of Gi was reported to be decreased in the aorta. We report that expression of G alpha 12 is selectively decreased in erythrocytes of humans with type 2 diabetes (DM2) and that these erythrocytes fail to release ATP in response to incubation with mastoparan 7 (10 microM), an agent that activates Gi. These results provide support for the hypothesis that ATP release from erythrocytes of humans with DM2 is impaired and this defect in erythrocyte physiology could contribute to the vascular disease associated with this clinical condition.
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Affiliation(s)
- Randy Sprague
- Saint Louis University, School of Medicine, Department of Pharmacological and Physiological Science, St. Louis, MO 63104, USA.
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