1
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Gannon HG, Riaz-Bradley A, Cann MJ. A Non-Functional Carbon Dioxide-Mediated Post-Translational Modification on Nucleoside Diphosphate Kinase of Arabidopsis thaliana. Int J Mol Sci 2024; 25:898. [PMID: 38255974 PMCID: PMC10815852 DOI: 10.3390/ijms25020898] [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: 12/11/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
The carbamate post-translational modification (PTM), formed by the nucleophilic attack of carbon dioxide by a dissociated lysine epsilon-amino group, is proposed as a widespread mechanism for sensing this biologically important bioactive gas. Here, we demonstrate the discovery and in vitro characterization of a carbamate PTM on K9 of Arabidopsis nucleoside diphosphate kinase (AtNDK1). We demonstrate that altered side chain reactivity at K9 is deleterious for AtNDK1 structure and catalytic function, but that CO2 does not impact catalysis. We show that nucleotide substrate removes CO2 from AtNDK1, and the carbamate PTM is functionless within the detection limits of our experiments. The AtNDK1 K9 PTM is the first demonstration of a functionless carbamate. In light of this finding, we speculate that non-functionality is a possible feature of the many newly identified carbamate PTMs.
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Affiliation(s)
- Harry G. Gannon
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; (H.G.G.)
| | - Amber Riaz-Bradley
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; (H.G.G.)
| | - Martin J. Cann
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; (H.G.G.)
- Biophysical Sciences Institute, Durham University, South Road, Durham DH1 3LE, UK
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2
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Abstract
Background Identifying CO2-binding proteins is vital for our knowledge of CO2-regulated molecular processes. The carbamate post-translational modification is a reversible CO2-mediated adduct that can form on neutral N-terminal α-amino or lysine ε-amino groups. Methods We have developed triethyloxonium ion (TEO) as a chemical proteomics tool to trap the carbamate post-translational modification on protein covalently. We use 13C-NMR and TEO and identify ubiquitin as a plant CO2-binding protein. Results We observe the carbamate post-translational modification on the Arabidopsis thaliana ubiquitin ε-amino groups of lysines 6, 33, and 48. We show that biologically relevant near atmospheric PCO2 levels increase ubiquitin conjugation dependent on lysine 6. We further demonstrate that CO2 increases the ubiquitin E2 ligase (AtUBC5) charging step via the transthioesterification reaction in which Ub is transferred from the E1 ligase active site to the E2 active site. Conclusions and general significance Therefore, plant ubiquitin is a CO2-binding protein, and the carbamate post-translational modification represents a potential mechanism through which plant cells can respond to fluctuating PCO2.
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Affiliation(s)
- Harry G Gannon
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | - Martin J Cann
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, South Road, Durham DH1 3LE, UK
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3
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Kryvenko V, Vadász I. Mechanisms of Hypercapnia-Induced Endoplasmic Reticulum Dysfunction. Front Physiol 2021; 12:735580. [PMID: 34867444 PMCID: PMC8640499 DOI: 10.3389/fphys.2021.735580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/27/2021] [Indexed: 01/16/2023] Open
Abstract
Protein transcription, translation, and folding occur continuously in every living cell and are essential for physiological functions. About one-third of all proteins of the cellular proteome interacts with the endoplasmic reticulum (ER). The ER is a large, dynamic cellular organelle that orchestrates synthesis, folding, and structural maturation of proteins, regulation of lipid metabolism and additionally functions as a calcium store. Recent evidence suggests that both acute and chronic hypercapnia (elevated levels of CO2) impair ER function by different mechanisms, leading to adaptive and maladaptive regulation of protein folding and maturation. In order to cope with ER stress, cells activate unfolded protein response (UPR) pathways. Initially, during the adaptive phase of ER stress, the UPR mainly functions to restore ER protein-folding homeostasis by decreasing protein synthesis and translation and by activation of ER-associated degradation (ERAD) and autophagy. However, if the initial UPR attempts for alleviating ER stress fail, a maladaptive response is triggered. In this review, we discuss the distinct mechanisms by which elevated CO2 levels affect these molecular pathways in the setting of acute and chronic pulmonary diseases associated with hypercapnia.
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Affiliation(s)
- Vitalii Kryvenko
- Department of Internal Medicine, Justus Liebig University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany
| | - István Vadász
- Department of Internal Medicine, Justus Liebig University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany.,Institute for Lung Health (ILH), Giessen, Germany
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4
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Linthwaite VL, Pawloski W, Pegg HB, Townsend PD, Thomas MJ, So VKH, Brown AP, Hodgson DRW, Lorimer GH, Fushman D, Cann MJ. Ubiquitin is a carbon dioxide-binding protein. SCIENCE ADVANCES 2021; 7:eabi5507. [PMID: 34559559 PMCID: PMC8462908 DOI: 10.1126/sciadv.abi5507] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
The identification of CO2-binding proteins is crucial to understanding CO2-regulated molecular processes. CO2 can form a reversible posttranslational modification through carbamylation of neutral N-terminal α-amino or lysine ε-amino groups. We have previously developed triethyloxonium (TEO) ion as a chemical proteomics tool for covalent trapping of carbamates, and here, we deploy TEO to identify ubiquitin as a mammalian CO2-binding protein. We use 13C-NMR spectroscopy to demonstrate that CO2 forms carbamates on the ubiquitin N terminus and ε-amino groups of lysines 6, 33, 48, and 63. We demonstrate that biologically relevant pCO2 levels reduce ubiquitin conjugation at lysine-48 and down-regulate ubiquitin-dependent NF-κB pathway activation. Our results show that ubiquitin is a CO2-binding protein and demonstrates carbamylation as a viable mechanism by which mammalian cells can respond to fluctuating pCO2.
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Affiliation(s)
| | - Wes Pawloski
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Hamish B. Pegg
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | | | | | - Victor K. H. So
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Adrian P. Brown
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - David R. W. Hodgson
- Department of Chemistry, Durham University, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Durham DH1 3LE, UK
| | - George H. Lorimer
- Biophysics Program, Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Martin J. Cann
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Durham DH1 3LE, UK
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5
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Kryvenko V, Wessendorf M, Tello K, Herold S, Morty RE, Seeger W, Vadász I. Hypercapnia-induces IRE1α-driven Endoplasmic Reticulum-associated Degradation of the Na,K-ATPase β-subunit. Am J Respir Cell Mol Biol 2021; 65:615-629. [PMID: 34192507 DOI: 10.1165/rcmb.2021-0114oc] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) is often associated with elevated levels of CO2 (hypercapnia) and impaired alveolar fluid clearance. Misfolding of the Na,K-ATPase (NKA), a key molecule involved in both alveolar epithelial barrier tightness and in resolution of alveolar edema, in the endoplasmic reticulum (ER) may decrease plasma membrane (PM) abundance of the transporter. Here, we investigated how hypercapnia affects the NKA β-subunit (NKA-β) in the ER. Exposing murine precision-cut lung slices (PCLS) and human alveolar epithelial A549 cells to elevated CO2 levels led to a rapid decrease of NKA-β abundance in the ER and at the cell surface. Knockdown of ER alpha-mannosidase I (MAN1B1) and ER degradation enhancing alpha-mannosidase like protein 1 by siRNA or treatment with the MAN1B1 inhibitor, kifunensine rescued loss of NKA-β in the ER, suggesting ER-associated degradation (ERAD) of the enzyme. Furthermore, hypercapnia activated the unfolded protein response (UPR) by promoting phosphorylation of inositol-requiring enzyme 1α (IRE1α) and treatment with a siRNA against IRE1α prevented the decrease of NKA-β in the ER. Of note, the hypercapnia-induced phosphorylation of IRE1α was triggered by a Ca2+-dependent mechanism. Additionally, inhibition of the inositol trisphosphate receptor decreased phosphorylation levels of IRE1α in PCLS and A549 cells, suggesting that Ca2+ efflux from the ER might be responsible for IRE1α activation and ERAD of NKA-β. In conclusion, here we provide evidence that hypercapnia attenuates maturation of the regulatory subunit of NKA by activating IRE1α and promoting ERAD, which may contribute to impaired alveolar epithelial integrity in patients with ARDS and hypercapnia.
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Affiliation(s)
- Vitalii Kryvenko
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany.,The Cardio-Pulmonary Institute, Giessen, Germany
| | - Miriam Wessendorf
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany
| | - Khodr Tello
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany.,The Cardio-Pulmonary Institute, Giessen, Germany
| | - Susanne Herold
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany.,The Cardio-Pulmonary Institute, Giessen, Germany
| | - Rory E Morty
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany.,The Cardio-Pulmonary Institute, Giessen, Germany.,Max-Planck-Institute for Heart and Lung Research, Department of Lung Development and Remodeling, Bad Nauheim, Germany
| | - Werner Seeger
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany.,The Cardio-Pulmonary Institute, Giessen, Germany.,Max-Planck-Institute for Heart and Lung Research, Department of Lung Development and Remodeling, Bad Nauheim, Germany.,Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany
| | - István Vadász
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany.,The Cardio-Pulmonary Institute, Giessen, Germany;
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6
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Kryvenko V, Vagin O, Dada LA, Sznajder JI, Vadász I. Maturation of the Na,K-ATPase in the Endoplasmic Reticulum in Health and Disease. J Membr Biol 2021; 254:447-457. [PMID: 34114062 PMCID: PMC8192048 DOI: 10.1007/s00232-021-00184-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/08/2021] [Indexed: 12/11/2022]
Abstract
Abstract The Na,K-ATPase establishes the electrochemical gradient of cells by driving an active exchange of Na+ and K+ ions while consuming ATP. The minimal functional transporter consists of a catalytic α-subunit and a β-subunit with chaperon activity. The Na,K-ATPase also functions as a cell adhesion molecule and participates in various intracellular signaling pathways. The maturation and trafficking of the Na,K-ATPase include co- and post-translational processing of the enzyme in the endoplasmic reticulum (ER) and the Golgi apparatus and subsequent delivery to the plasma membrane (PM). The ER folding of the enzyme is considered as the rate-limiting step in the membrane delivery of the protein. It has been demonstrated that only assembled Na,K-ATPase α:β-complexes may exit the organelle, whereas unassembled, misfolded or unfolded subunits are retained in the ER and are subsequently degraded. Loss of function of the Na,K-ATPase has been associated with lung, heart, kidney and neurological disorders. Recently, it has been shown that ER dysfunction, in particular, alterations in the homeostasis of the organelle, as well as impaired ER-resident chaperone activity may impede folding of Na,K-ATPase subunits, thus decreasing the abundance and function of the enzyme at the PM. Here, we summarize our current understanding on maturation and subsequent processing of the Na,K-ATPase in the ER under physiological and pathophysiological conditions. Graphic Abstract ![]()
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Affiliation(s)
- Vitalii Kryvenko
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany
| | - Olga Vagin
- Department of Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA.,Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Laura A Dada
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - István Vadász
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany. .,The Cardio-Pulmonary Institute (CPI), Giessen, Germany.
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7
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Phelan DE, Mota C, Lai C, Kierans SJ, Cummins EP. Carbon dioxide-dependent signal transduction in mammalian systems. Interface Focus 2021; 11:20200033. [PMID: 33633832 PMCID: PMC7898142 DOI: 10.1098/rsfs.2020.0033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 12/15/2022] Open
Abstract
Carbon dioxide (CO2) is a fundamental physiological gas known to profoundly influence the behaviour and health of millions of species within the plant and animal kingdoms in particular. A recent Royal Society meeting on the topic of 'Carbon dioxide detection in biological systems' was extremely revealing in terms of the multitude of roles that different levels of CO2 play in influencing plants and animals alike. While outstanding research has been performed by leading researchers in the area of plant biology, neuronal sensing, cell signalling, gas transport, inflammation, lung function and clinical medicine, there is still much to be learned about CO2-dependent sensing and signalling. Notably, while several key signal transduction pathways and nodes of activity have been identified in plants and animals respectively, the precise wiring and sensitivity of these pathways to CO2 remains to be fully elucidated. In this article, we will give an overview of the literature relating to CO2-dependent signal transduction in mammalian systems. We will highlight the main signal transduction hubs through which CO2-dependent signalling is elicited with a view to better understanding the complex physiological response to CO2 in mammalian systems. The main topics of discussion in this article relate to how changes in CO2 influence cellular function through modulation of signal transduction networks influenced by pH, mitochondrial function, adenylate cyclase, calcium, transcriptional regulators, the adenosine monophosphate-activated protein kinase pathway and direct CO2-dependent protein modifications. While each of these topics will be discussed independently, there is evidence of significant cross-talk between these signal transduction pathways as they respond to changes in CO2. In considering these core hubs of CO2-dependent signal transduction, we hope to delineate common elements and identify areas in which future research could be best directed.
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Affiliation(s)
- D. E. Phelan
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - C. Mota
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - C. Lai
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - S. J. Kierans
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - E. P. Cummins
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
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8
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Nijjar S, Maddison D, Meigh L, de Wolf E, Rodgers T, Cann MJ, Dale N. Opposing modulation of Cx26 gap junctions and hemichannels by CO 2. J Physiol 2020; 599:103-118. [PMID: 33022747 DOI: 10.1113/jp280747] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 10/02/2020] [Indexed: 01/21/2023] Open
Abstract
KEY POINTS A moderate increase in P C O 2 (55 mmHg) closes Cx26 gap junctions. This effect of CO2 is independent of changes in intra- or extracellular pH. The CO2 -dependent closing effect depends on the same residues (K125 and R104) that are required for the CO2 -dependent opening of Cx26 hemichannels. Pathological mutations of Cx26 abolish the CO2 -dependent closing of the gap junction. Elastic network modelling suggests that the effect of CO2 on Cx26 hemichannels and gap junctions is mediated through changes in the lowest entropy state of the protein. ABSTRACT Cx26 hemichannels open in response to moderate elevations of CO2 ( P C O 2 55 mmHg) via a carbamylation reaction that depends on residues K125 and R104. Here we investigate the action of CO2 on Cx26 gap junctions. Using a dye transfer assay, we found that an elevated P C O 2 of 55 mmHg greatly delayed the permeation of a fluorescent glucose analogue (NBDG) between HeLa cells coupled by Cx26 gap junctions. However, the mutations K125R or R104A abolished this effect of CO2 . Whole cell recordings demonstrated that elevated CO2 reduced the Cx26 gap junction conductance (median reduction 66.7%, 95% CI, 50.5-100.0%) but had no effect on Cx26K125R or Cx31 gap junctions. CO2 can cause intracellular acidification. Using 30 mm propionate, we found that acidification in the absence of a change in P C O 2 caused a median reduction in the gap junction conductance of 41.7% (95% CI, 26.6-53.7%). This effect of propionate was unaffected by the K125R mutation (median reduction 48.1%, 95% CI, 28.0-86.3%). pH-dependent and CO2 -dependent closure of the gap junction are thus mechanistically independent. Mutations of Cx26 associated with the keratitis ichthyosis deafness syndrome (N14K, A40V and A88V), in combination with the mutation M151L, also abolished the CO2 -dependent gap junction closure. Elastic network modelling suggests that the lowest entropy state when CO2 is bound is the closed configuration for the gap junction but the open state for the hemichannel. The opposing actions of CO2 on Cx26 gap junctions and hemichannels thus depend on the same residues and presumed carbamylation reaction.
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Affiliation(s)
- Sarbjit Nijjar
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Daniel Maddison
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Louise Meigh
- School of Life Sciences, University of Warwick, Coventry, UK
| | | | - Thomas Rodgers
- School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Martin J Cann
- Department of Biosciences, Durham University, Durham, UK
| | - Nicholas Dale
- School of Life Sciences, University of Warwick, Coventry, UK
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9
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Rackwitz R, Gäbel G. Effects of dissolved carbon dioxide on the integrity of the rumen epithelium: An agent in the development of ruminal acidosis. J Anim Physiol Anim Nutr (Berl) 2017; 102:e345-e352. [PMID: 28608583 DOI: 10.1111/jpn.12752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/21/2017] [Indexed: 01/20/2023]
Abstract
The carbon dioxide released and dissolved in rumen fluid may easily permeate across the epithelial cell membrane. Thus, we hypothesized that CO2 may act as proton carrier and induce epithelial damage under acidotic conditions. Ovine ruminal epithelia were mounted in Ussing chambers under short-circuit conditions. The serosal buffer solution had a constant pH of 7.4 and was gassed either with 100% oxygen or with carbogen (95% O2 /5% CO2 ). The mucosal solution was gassed with either 100% oxygen or 100% carbon dioxide. The mucosal pH was lowered stepwise from 6.6 to 5.0 in the presence or absence of short-chain fatty acids (SCFA). The transepithelial conductance (Gt ) as an indicator of epithelial integrity and the short-circuit current (Isc ) as an indicator of active electrogenic ion transfer were continuously monitored. At an initial mucosal pH of 6.6, there was no significant difference in Gt between the treatment groups. In the absence of both SCFA and CO2 , Gt remained constant when the mucosal solution was acidified to pH 5.0. In the presence of SCFA, mucosal acidification induced a significant rise in Gt when the solutions were gassed with oxygen. A small increase in Gt was observed in the mucosal presence of CO2 . However, no difference in final Gt was observed between SCFA-containing and SCFA-free conditions under carbon dioxide gassing during stepwise mucosal acidification. The SCFA+proton-induced increase in Gt could also be minimized by serosal gassing with carbogen. Because of the SCFA+proton-induced changes in Gt and their attenuation by CO2 , a protective role for mucosally available carbon dioxide may be assumed. We suggest that this effect may be due to the intraepithelial conversion of carbon dioxide to bicarbonate. However, the serosal presence of CO2 at a physiological concentration may be sufficient to protect the epithelia from SCFA+proton-induced damage for a certain period of time.
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Affiliation(s)
- R Rackwitz
- Institute for Veterinary Physiology, University of Leipzig, Leipzig, Germany
| | - G Gäbel
- Institute for Veterinary Physiology, University of Leipzig, Leipzig, Germany
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10
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Hug MJ. CO 2- friend or foe? J Physiol 2016; 594:1521. [DOI: 10.1113/jp271882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 01/04/2016] [Indexed: 11/08/2022] Open
Affiliation(s)
- Martin J. Hug
- Pharmacy; Medical Center, University of Freiburg; Hugstetter Str. 55 D-79106 Freiburg Germany
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11
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Turner MJ, Saint-Criq V, Patel W, Ibrahim SH, Verdon B, Ward C, Garnett JP, Tarran R, Cann MJ, Gray MA. Hypercapnia modulates cAMP signalling and cystic fibrosis transmembrane conductance regulator-dependent anion and fluid secretion in airway epithelia. J Physiol 2015; 594:1643-61. [PMID: 26574187 PMCID: PMC4799982 DOI: 10.1113/jp271309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/05/2015] [Indexed: 12/20/2022] Open
Abstract
Hypercapnia is clinically defined as an arterial blood partial pressure of CO2 of above 40 mmHg and is a feature of chronic lung disease. In previous studies we have demonstrated that hypercapnia modulates agonist-stimulated cAMP levels through effects on transmembrane adenylyl cyclase activity. In the airways, cAMP is known to regulate cystic fibrosis transmembrane conductance regulator (CFTR)-mediated anion and fluid secretion, which contributes to airway surface liquid homeostasis. The aim of the current work was to investigate if hypercapnia could modulate cAMP-regulated ion and fluid transport in human airway epithelial cells. We found that acute exposure to hypercapnia significantly reduced forskolin-stimulated elevations in intracellular cAMP as well as both adenosine- and forskolin-stimulated increases in CFTR-dependent transepithelial short-circuit current, in polarised cultures of Calu-3 human airway cells. This CO2 -induced reduction in anion secretion was not due to a decrease in HCO3 (-) transport given that neither a change in CFTR-dependent HCO3 (-) efflux nor Na(+) /HCO3 (-) cotransporter-dependent HCO3 (-) influx were CO2 -sensitive. Hypercapnia also reduced the volume of forskolin-stimulated fluid secretion over 24 h, yet had no effect on the HCO3 (-) content of the secreted fluid. Our data reveal that hypercapnia reduces CFTR-dependent, electrogenic Cl(-) and fluid secretion, but not CFTR-dependent HCO3 (-) secretion, which highlights a differential sensitivity of Cl(-) and HCO3 (-) transporters to raised CO2 in Calu-3 cells. Hypercapnia also reduced forskolin-stimulated CFTR-dependent anion secretion in primary human airway epithelia. Based on current models of airways biology, a reduction in fluid secretion, associated with hypercapnia, would be predicted to have important consequences for airways hydration and the innate defence mechanisms of the lungs.
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Affiliation(s)
- Mark J Turner
- Institute for Cell & Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.,Department of Physiology, McIntyre Medical Sciences Building, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada, H3G 1Y6
| | - Vinciane Saint-Criq
- Institute for Cell & Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Waseema Patel
- Institute for Cell & Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Salam H Ibrahim
- Institute for Cell & Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Bernard Verdon
- Institute for Cell & Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Christopher Ward
- Institute for Cellular Medicine, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - James P Garnett
- Institute for Cell & Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Robert Tarran
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Martin J Cann
- School of Biological and Biomedical Sciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Michael A Gray
- Institute for Cell & Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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12
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Nunes AR, Holmes AP, Conde SV, Gauda EB, Monteiro EC. Revisiting cAMP signaling in the carotid body. Front Physiol 2014; 5:406. [PMID: 25389406 PMCID: PMC4211388 DOI: 10.3389/fphys.2014.00406] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 10/01/2014] [Indexed: 12/25/2022] Open
Abstract
Chronic carotid body (CB) activation is now recognized as being essential in the development of hypertension and promoting insulin resistance; thus, it is imperative to characterize the chemotransduction mechanisms of this organ in order to modulate its activity and improve patient outcomes. For several years, and although controversial, cyclic adenosine monophosphate (cAMP) was considered an important player in initiating the activation of the CB. However, its relevance was partially displaced in the 90s by the emerging role of the mitochondria and molecules such as AMP-activated protein kinase and O2-sensitive K+ channels. Neurotransmitters/neuromodulators binding to metabotropic receptors are essential to chemotransmission in the CB, and cAMP is central to this process. cAMP also contributes to raise intracellular Ca2+ levels, and is intimately related to the cellular energetic status (AMP/ATP ratio). Furthermore, cAMP signaling is a target of multiple current pharmacological agents used in clinical practice. This review (1) provides an outline on the classical view of the cAMP-signaling pathway in the CB that originally supported its role in the O2/CO2 sensing mechanism, (2) presents recent evidence on CB cAMP neuromodulation and (3) discusses how CB activity is affected by current clinical therapies that modify cAMP-signaling, namely dopaminergic drugs, caffeine (modulation of A2A/A2B receptors) and roflumilast (PDE4 inhibitors). cAMP is key to any process that involves metabotropic receptors and the intracellular pathways involved in CB disease states are likely to involve this classical second messenger. Research examining the potential modification of cAMP levels and/or interactions with molecules associated with CB hyperactivity is currently in its beginning and this review will open doors for future explorations.
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Affiliation(s)
- Ana R Nunes
- CEDOC, Chronic Diseases Research Center, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa Lisboa, Portugal
| | - Andrew P Holmes
- School of Clinical and Experimental Medicine, University of Birmingham Birmingham, UK
| | - Sílvia V Conde
- CEDOC, Chronic Diseases Research Center, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa Lisboa, Portugal
| | - Estelle B Gauda
- Neonatology Research Laboratories, Department of Pediatrics, Johns Hopkins Medical Institutions, Johns Hopkins University Baltimore, MD, USA
| | - Emília C Monteiro
- CEDOC, Chronic Diseases Research Center, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa Lisboa, Portugal
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Sharabi K, Charar C, Friedman N, Mizrahi I, Zaslaver A, Sznajder JI, Gruenbaum Y. The response to high CO2 levels requires the neuropeptide secretion component HID-1 to promote pumping inhibition. PLoS Genet 2014; 10:e1004529. [PMID: 25101962 PMCID: PMC4125093 DOI: 10.1371/journal.pgen.1004529] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 06/09/2014] [Indexed: 11/19/2022] Open
Abstract
Carbon dioxide (CO2) is a key molecule in many biological processes; however, mechanisms by which organisms sense and respond to high CO2 levels remain largely unknown. Here we report that acute CO2 exposure leads to a rapid cessation in the contraction of the pharynx muscles in Caenorhabditis elegans. To uncover the molecular mechanisms underlying this response, we performed a forward genetic screen and found that hid-1, a key component in neuropeptide signaling, regulates this inhibition in muscle contraction. Surprisingly, we found that this hid-1-mediated pathway is independent of any previously known pathways controlling CO2 avoidance and oxygen sensing. In addition, animals with mutations in unc-31 and egl-21 (neuropeptide secretion and maturation components) show impaired inhibition of muscle contraction following acute exposure to high CO2 levels, in further support of our findings. Interestingly, the observed response in the pharynx muscle requires the BAG neurons, which also mediate CO2 avoidance. This novel hid-1-mediated pathway sheds new light on the physiological effects of high CO2 levels on animals at the organism-wide level.
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Affiliation(s)
- Kfir Sharabi
- Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Chayki Charar
- Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nurit Friedman
- Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Inbar Mizrahi
- Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alon Zaslaver
- Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jacob I. Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Yosef Gruenbaum
- Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail:
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Naderi S, Nikdel A, Meshram M, McConkey B, Ingalls B, Budman H, Scharer J. Modeling of cell culture damage and recovery leads to increased antibody and biomass productivity in CHO cell cultures. Biotechnol J 2014; 9:1152-63. [DOI: 10.1002/biot.201300287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 04/01/2014] [Accepted: 05/18/2014] [Indexed: 12/12/2022]
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15
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Cummins EP, Selfridge AC, Sporn PH, Sznajder JI, Taylor CT. Carbon dioxide-sensing in organisms and its implications for human disease. Cell Mol Life Sci 2013; 71:831-45. [PMID: 24045706 DOI: 10.1007/s00018-013-1470-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 08/22/2013] [Accepted: 08/30/2013] [Indexed: 12/29/2022]
Abstract
The capacity of organisms to sense changes in the levels of internal and external gases and to respond accordingly is central to a range of physiologic and pathophysiologic processes. Carbon dioxide, a primary product of oxidative metabolism is one such gas that can be sensed by both prokaryotic and eukaryotic cells and in response to altered levels, elicit the activation of multiple adaptive pathways. The outcomes of activating CO2-sensitive pathways in various species include increased virulence of fungal and bacterial pathogens, prey-seeking behavior in insects as well as taste perception, lung function, and the control of immunity in mammals. In this review, we discuss what is known about the mechanisms underpinning CO2 sensing across a range of species and consider the implications of this for physiology, disease progression, and the possibility of developing new therapeutics for inflammatory and infectious disease.
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Affiliation(s)
- Eoin P Cummins
- School of Medicine and Medical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
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Nunes AR, Holmes APS, Sample V, Kumar P, Cann MJ, Monteiro EC, Zhang J, Gauda EB. Bicarbonate-sensitive soluble and transmembrane adenylyl cyclases in peripheral chemoreceptors. Respir Physiol Neurobiol 2013; 188:83-93. [PMID: 23727159 DOI: 10.1016/j.resp.2013.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 05/09/2013] [Accepted: 05/13/2013] [Indexed: 12/17/2022]
Abstract
Stimulation of the carotid body (CB) chemoreceptors by hypercapnia triggers a reflex ventilatory response via a cascade of cellular events, which includes generation of cAMP. However, it is not known if molecular CO2/HCO3(-) and/or H(+) mediate this effect and how these molecules contribute to cAMP production. We previously reported that the CB highly expresses HCO3(-)-sensitive soluble adenylyl cyclase (sAC). In the present study we systematically characterize the role of sAC in the CB, comparing the effect of isohydric hypercapnia (IH) in cAMP generation through activation of sAC or transmembrane-adenylyl cyclase (tmAC). Pharmacological deactivation of sAC and tmAC decreased the CB cAMP content in normocapnia and IH with no differences between these two conditions. Changes from normocapnia to IH did not effect the degree of PKA activation and the carotid sinus nerve discharge frequency. sAC and tmAC are functional in CB but intracellular elevations in CO2/HCO3(-) in IH conditions on their own are insufficient to further activate these enzymes, suggesting that the hypercapnic response is dependent on secondary acidosis.
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Affiliation(s)
- Ana R Nunes
- Department of Pediatrics, Johns Hopkins Medical Institutions, Baltimore, MD 21287-3200, USA
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