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Cerecedo D, Martínez-Vieyra I, Hernández-Rojo I, Hernández-Cruz A, Rincón-Heredia R, Millán-Aldaco D, Mendoza-Garrido ME. Reactive oxygen species downregulate dystroglycans in the megakaryocytes of rats with arterial hypertension. Exp Cell Res 2023; 433:113847. [PMID: 37931771 DOI: 10.1016/j.yexcr.2023.113847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/28/2023] [Accepted: 10/29/2023] [Indexed: 11/08/2023]
Abstract
Hypertension is a multifactorial disease characterized by vascular and renal dysfunction, cardiovascular remodeling, inflammation, and fibrosis, all of which are associated with oxidative stress. We previously demonstrated cellular reactive oxygen species (ROS) imbalances may impact the structural and biochemical functions of blood cells and reported downregulation of β-dystroglycan (β-Dg) and overexpression of the epithelial sodium channel (ENaC) contribute to the pathophysiology of hypertension. In this study, we aimed to determine the expression of dystroglycans (Dg) and ENaC in platelet progenitors (megakaryocytes) and their surrounding niches. Thin sections of bone marrow from 5- and 28-week-old spontaneous hypertensive rats (SHR) were compared to age-matched normotensive rats (WKY). Cytometry and immunohistochemical assays demonstrated an oxidative environment in SHR bone marrow, characterized by high levels of myeloperoxidase and 3-nitrotyrosine and downregulation of peroxiredoxin II. In addition, transmission electron micrography and confocal microscopy revealed morphological changes in platelets and Mgks from SHR rats, including swollen mitochondria. Quantitative qRT-PCR assays confirmed downregulation of Dg mRNA and immunohistochemistry and western-blotting validated low expression of β-Dg, mainly in the phosphorylated form, in Mgks from 28-week-old SHR rats. Moreover, we observed a progressive increase in β-1 integrin expression in Mgks and extracellular matrix proteins in Mgk niches in SHR rats compared to WKY controls. These results indicate accumulation of ROS promotes oxidative stress within the bone marrow environment and detrimentally affects cellular homeostasis in hypertensive individuals.
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Affiliation(s)
- Doris Cerecedo
- Laboratorio de Hematobiología, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City, Mexico.
| | - Ivette Martínez-Vieyra
- Laboratorio de Hematobiología, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Isaac Hernández-Rojo
- Laboratorio de Hematobiología, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Arturo Hernández-Cruz
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ruth Rincón-Heredia
- Microscopy Core Unit, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Diana Millán-Aldaco
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Maria Eugenia Mendoza-Garrido
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City, Mexico
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Zhang M, Zhang X, Pei J, Guo B, Zhang G, Li M, Huang L. Identification of phytochemical compounds of Fagopyrum dibotrys and their targets by metabolomics, network pharmacology and molecular docking studies. Heliyon 2023; 9:e14029. [PMID: 36911881 PMCID: PMC9977108 DOI: 10.1016/j.heliyon.2023.e14029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 01/30/2023] [Accepted: 02/19/2023] [Indexed: 03/05/2023] Open
Abstract
Acute lung injury (ALI) is a clinically severe lung illness with high incidence rate and mortality. Especially, coronavirus disease 2019 (COVID-19) poses a serious threat to world wide governmental fitness. It has distributed to almost from corner to corner of the universe, and the situation in the prevention and control of COVID-19 remains grave. Traditional Chinese medicine plays a vital role in the precaution and therapy of sicknesses. At present, there is a lack of drugs for treating these diseases, so it is necessary to develop drugs for treating COVID-19 related ALI. Fagopyrum dibotrys (D. Don) Hara is an annual plant of the Polygonaceae family and one of the long-history used traditional medicine in China. In recent years, its rhizomes (medicinal parts) have attracted the attention of scholars at home and abroad due to their significant anti-inflammatory, antibacterial and anticancer activities. It can work on SARS-COV-2 with numerous components, targets, and pathways, and has a certain effect on coronavirus disease 2019 (COVID-19) related acute lung injury (ALI). However, there are few systematic studies on its aerial parts (including stems and leaves) and its potential therapeutic mechanism has not been studied. The phytochemical constituents of rhizome of F. dibotrys were collected using TCMSP database. And metabolites of F. dibotrys' s aerial parts were detected by metabonomics. The phytochemical targets of F. dibotrys were predicted by the PharmMapper website tool. COVID-19 and ALI-related genes were retrieved from GeneCards. Cross targets and active phytochemicals of COVID-19 and ALI related genes in F. dibotrys were enriched by gene ontology (GO) and KEGG by metscape bioinformatics tools. The interplay network entre active phytochemicals and anti COVID-19 and ALI targets was established and broke down using Cytoscape software. Discovery Studio (version 2019) was used to perform molecular docking of crux active plant chemicals with anti COVID-19 and ALI targets. We identified 1136 chemicals from the aerial parts of F. dibotrys, among which 47 were active flavonoids and phenolic chemicals. A total of 61 chemicals were searched from the rhizome of F. dibotrys, and 15 of them were active chemicals. So there are 6 commonly key active chemicals at the aerial parts and the rhizome of F. dibotrys, 89 these phytochemicals's potential targets, and 211 COVID-19 and ALI related genes. GO enrichment bespoken that F. dibotrys might be involved in influencing gene targets contained numerous biological processes, for instance, negative regulation of megakaryocyte differentiation, regulation of DNA metabolic process, which could be put down to its anti COVID-19 associated ALI effects. KEGG pathway indicated that viral carcinogenesis, spliceosome, salmonella infection, coronavirus disease - COVID-19, legionellosis and human immunodeficiency virus 1 infection pathway are the primary pathways obsessed in the anti COVID-19 associated ALI effects of F. dibotrys. Molecular docking confirmed that the 6 critical active phytochemicals of F. dibotrys, such as luteolin, (+) -epicatechin, quercetin, isorhamnetin, (+) -catechin, and (-) -catechin gallate, can combine with kernel therapeutic targets NEDD8, SRPK1, DCUN1D1, and PARP1. In vitro activity experiments showed that the total antioxidant capacity of the aerial parts and rhizomes of F. dibotrys increased with the increase of concentration in a certain range. In addition, as a whole, the antioxidant capacity of the aerial part of F. dibotrys was stronger than that of the rhizome. Our research afford cues for farther exploration of the anti COVID-19 associated ALI chemical compositions and mechanisms of F. dibotrys and afford scientific foundation for progressing modern anti COVID-19 associated ALI drugs based on phytochemicals in F. dibotrys. We also fully developed the medicinal value of F. dibotrys' s aerial parts, which can effectively avoid the waste of resources. Meanwhile, our work provides a new strategy for integrating metabonomics, network pharmacology, and molecular docking techniques which was an efficient way for recognizing effective constituents and mechanisms valid to the pharmacologic actions of traditional Chinese medicine.
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Key Words
- ARDS, acute respiratory distress syndrome
- BC, BetweennessCentrality
- CC, ClosenessCentrality
- CHM, Chinese herbal medicines
- COVID-19 related ALI, Coronavirus disease 2019 related acute lung injury
- Coronavirus disease 2019 related acute lung injury
- DL, drug-like properties
- Fagopyrum dibotrys
- GO, Gene Ontology
- KEGG, Kyoto Encyclopedia of Genes and Genomes
- LC-MS, liquid chromatography-mass spectrometry
- Metabolomics
- Molecular docking
- NC, NeighborhoodConnectivity
- NSCLC, Non-small cell lung carcinoma
- Network pharmacology
- OB, oral bioavailability
- PARP-1, Poly(ADP-ribose)polymerase-1
- PDB, Protein Data Bank database
- PPI network, protein-protein interaction network
- RMSD, Root mean square deviation
- SARS-CoV-2, severe acute respiratory syndrome coronavirus 2
- TCM, traditional Chinese medicine
- TCMSP, traditional Chinese medicine systems pharmacology database and analysis platform
- WTM, widely targeted metabolome
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Affiliation(s)
- Min Zhang
- A Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
- College of Pharmacy, Baotou Medical College, Baotou, 014040, China
- Inner Mongolia Autonomous Region Hospital of Traditional Chinese Medicine, Hohhot, 010020, China
- Inner Mongolia Academy of Chinese and Mongolian Medicine, Hohhot, 010010, China
| | - Xinke Zhang
- A Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
| | - Jin Pei
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Baolin Guo
- A Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
| | - Guoshuai Zhang
- A Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
| | - Minhui Li
- College of Pharmacy, Baotou Medical College, Baotou, 014040, China
- Inner Mongolia Autonomous Region Hospital of Traditional Chinese Medicine, Hohhot, 010020, China
- Inner Mongolia Academy of Chinese and Mongolian Medicine, Hohhot, 010010, China
- Corresponding author. College of Pharmacy, Baotou Medical College, Baotou, 014040, China.
| | - Linfang Huang
- A Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of the People's Republic of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, China
- Corresponding author.
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Grant GJ, Mimche PN, Paine R, Liou TG, Qian WJ, Helms MN. Enhanced epithelial sodium channel activity in neonatal Scnn1b mouse lung attenuates high oxygen-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2021; 321:L29-L41. [PMID: 33949206 PMCID: PMC8321857 DOI: 10.1152/ajplung.00538.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 11/22/2022] Open
Abstract
Prolonged oxygen therapy leads to oxidative stress, epithelial dysfunction, and acute lung injury in preterm infants and adults. Heterozygous Scnn1b mice, which overexpress lung epithelial sodium channels (ENaC), and their wild-type (WT) C57Bl6 littermates were utilized to study the pathogenesis of high fraction inspired oxygen ([Formula: see text])-induced lung injury. Exposure to high [Formula: see text] from birth to postnatal (PN) day 11 was used to model oxidative stress. Chronic exposure of newborn pups to 85% O2 increased glutathione disulfide (GSSG) and elevated the GSH/GSSG redox potential (Eh) of bronchoalveolar lavage fluid (BALF). Longitudinal X-ray imaging and Evans blue-labeled-albumin assays showed that chronic 85% O2 and acute GSSG (400 µM) exposures decreased alveolar fluid clearance (AFC) in the WT lung. Morphometric analysis of WT pups insufflated with GSSG (400 µM) or amiloride (1 µM) showed a reduction in alveologenesis and increased lung injury compared with age-matched control pups. The Scnn1b mouse lung phenotype was not further aggravated by chronic 85% O2 exposure. These outcomes support the hypothesis that exposure to hyperoxia increases GSSG, resulting in reduced lung fluid reabsorption due to inhibition of amiloride-sensitive ENaC. Flavin adenine dinucleotide (FADH2; 10 µM) was effective in recycling GSSG in vivo and promoted alveologenesis, but did not impact AFC nor attenuate fibrosis following high [Formula: see text] exposure. In conclusion, the data indicate that FADH2 may be pivotal for normal lung development, and show that ENaC is a key factor in promoting alveologenesis, sustaining AFC, and attenuating fibrotic lung injury caused by prolonged oxygen therapy in WT mice.
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Affiliation(s)
- Garett J Grant
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Patrice N Mimche
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, Utah
| | - Robert Paine
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Theodore G Liou
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Wei-Jun Qian
- Biological Science Division, Pacific Northwest National Laboratory, Richland, Washington
| | - My N Helms
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
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Mraheil MA, Toque HA, La Pietra L, Hamacher J, Phanthok T, Verin A, Gonzales J, Su Y, Fulton D, Eaton DC, Chakraborty T, Lucas R. Dual Role of Hydrogen Peroxide as an Oxidant in Pneumococcal Pneumonia. Antioxid Redox Signal 2021; 34:962-978. [PMID: 32283950 PMCID: PMC8035917 DOI: 10.1089/ars.2019.7964] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Significance:Streptococcus pneumoniae (Spn), a facultative anaerobic Gram-positive human pathogen with increasing rates of penicillin and macrolide resistance, is a major cause of lower respiratory tract infections worldwide. Pneumococci are a primary agent of severe pneumonia in children younger than 5 years and of community-acquired pneumonia in adults. A major defense mechanism toward Spn is the generation of reactive oxygen species, including hydrogen peroxide (H2O2), during the oxidative burst of neutrophils and macrophages. Paradoxically, Spn produces high endogenous levels of H2O2 as a strategy to promote colonization. Recent Advances: Pneumococci, which express neither catalase nor common regulators of peroxide stress resistance, have developed unique mechanisms to protect themselves from H2O2. Spn generates high levels of H2O2 as a strategy to promote colonization. Production of H2O2 moreover constitutes an important virulence phenotype and its cellular activities overlap and complement those of other virulence factors, such as pneumolysin, in modulating host immune responses and promoting organ injury. Critical Issues: This review examines the dual role of H2O2 in pneumococcal pneumonia, from the viewpoint of both the pathogen (defense mechanisms, lytic activity toward competing pathogens, and virulence) and the resulting host-response (inflammasome activation, endoplasmic reticulum stress, and damage to the alveolar-capillary barrier in the lungs). Future Directions: An understanding of the complexity of H2O2-mediated host-pathogen interactions is necessary to develop novel strategies that target these processes to enhance lung function during severe pneumonia.
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Affiliation(s)
- Mobarak Abu Mraheil
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Haroldo A Toque
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Luigi La Pietra
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Juerg Hamacher
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland.,Internal Medicine V-Pneumology, Allergology, Respiratory and Environmental Medicine, Faculty of Medicine, Saarland University, Saarbrücken, Germany
| | - Tenzing Phanthok
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Alexander Verin
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Joyce Gonzales
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - David Fulton
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Douglas C Eaton
- Department of Medicine, Emory School of Medicine, Atlanta, Georgia, USA
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Rudolf Lucas
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
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Cannon SC. Epilepsy channelopathies go neddy: stabilizing NaV1.1 channels by neddylation. J Clin Invest 2021; 131:148370. [PMID: 33855971 DOI: 10.1172/jci148370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Loss-of-function mutations of SCN1A encoding the pore-forming α subunit of the NaV1.1 neuronal sodium channel cause a severe developmental epileptic encephalopathy, Dravet syndrome (DS). In this issue of the JCI, Chen, Luo, Gao, et al. describe a phenocopy for DS in mice deficient for posttranslational conjugation with neural precursor cell expressed, developmentally downregulated 8 (NEDD8) (neddylation), selectively engineered in inhibitory interneurons. Pursuing the possibility that this phenotype is also caused by loss of NaV1.1, Chen, Luo, Gao, and colleagues show that interneuron excitability and GABA release are impaired, NaV1.1 degradation rate is increased with a commensurate decrease of NaV1.1 protein, and NaV1.1 is a substrate for neddylation. These findings establish neddylation as a mechanism for stabilizing NaV1.1 subunits and suggest another pathomechanism for epileptic sodium channelopathy.
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Zou T, Zhang J. Diverse and pivotal roles of neddylation in metabolism and immunity. FEBS J 2020; 288:3884-3912. [PMID: 33025631 DOI: 10.1111/febs.15584] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 12/11/2022]
Abstract
Neddylation is one type of protein post-translational modification by conjugating a ubiquitin-like protein neural precursor cell-expressed developmentally downregulated protein 8 to substrate proteins via a cascade involving E1, E2, and E3 enzymes. The best-characterized substrates of neddylation are cullins, essential components of cullin-RING E3 ubiquitin-ligase complexes. The discovery of noncullin neddylation targets indicates that neddylation may have diverse biological functions. Indeed, neddylation has been implicated in various cellular processes including cell cycle progression, metabolism, immunity, and tumorigenesis. Here, we summarized the reported neddylation substrates and also discuss the functions of neddylation in the immune system and metabolism.
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Affiliation(s)
- Tao Zou
- Beijing Institute of Brain Sciences, China
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7
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Pick E. The necessity of NEDD8/Rub1 for vitality and its association with mitochondria-derived oxidative stress. Redox Biol 2020; 37:101765. [PMID: 33099217 PMCID: PMC7582104 DOI: 10.1016/j.redox.2020.101765] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/12/2020] [Accepted: 10/16/2020] [Indexed: 01/04/2023] Open
Abstract
Access of molecular oxygen to the respiratory electron transport chain at the mitochondria costs in the generation of reactive oxygen-derived species (ROS). ROS induces progressive damage to macromolecules in all living cells, hence, rapid defense mechanisms to maintain cellular redox homeostasis are vital. NEDD8/Rub1 is a highly conserved ubiquitin-like modifier that has recently been identified as a key regulator of cellular redox homeostasis. In this review, I will present NEDD8/Rub1, its modification cascade of enzymes, substrates and hydrolases. After introduction, I will show that the NEDD8/Rub1 pathway is linked with mitochondria physiology, namely, oxidative stress. In the rest of the review, I will approach the Ascomycota phylum of the kingdom fungi instrumentally, to present existing links between NEDD8/Rub1 vitality and the aerobic lifestyle of model species belonging to three subphyla: Saccharomycotina (S. cerevisiae and C. albicans), Pezizomycotina (A. nidulans and N. crassa), and Taphrinomycotina (S. pombe). NEDD8/Rub1 is a key regulator of cellular redox homeostasis. Ascomycota species that produce mitochondria-derived ROS during glycolysis require NEDD8/Rub1for viability. NEDD8/Rub1 essentiality correlates with the existence of NEDP1 in the organism genome.
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Affiliation(s)
- Elah Pick
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Tivon, 3600600, Israel.
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8
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Chase LA, VerHeulen Kleyn M, Schiller N, King AG, Flores G, Engelsman SB, Bowles C, Smith SL, Robinson AE, Rothstein J. Hydrogen peroxide triggers an increase in cell surface expression of system x c- in cultured human glioma cells. Neurochem Int 2019; 134:104648. [PMID: 31874187 DOI: 10.1016/j.neuint.2019.104648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/15/2019] [Accepted: 12/18/2019] [Indexed: 12/14/2022]
Abstract
System xc- exchanges extracellular cystine for intracellular glutamate across the plasma membrane of many cell types. One of the physiological roles of System xc- is to provide cystine for synthesis of the antioxidant glutathione. Here we report that hydrogen peroxide (H2O2) triggers the translocation of System xc- to the plasma membrane within 10 min of the initial exposure. Specifically, we observed a three-fold increase in 35S-l-cystine uptake following a 10 min exposure to 0.3 mM H2O2. This effect was dose-dependent with an EC50 for H2O2 of 65 μM. We then used cell surface biotinylation analysis to test the hypothesis that the increase in activity is due to an increased number of transporters on the plasma membrane. We demonstrated that the amount of transporter protein, xCT, localized to the plasma membrane doubles within 10 min of H2O2 exposure as a result of an increase in its delivery rate and a reduction in its internalization rate. In addition, we demonstrated that H2O2 triggered a rapid decrease in total cellular glutathione which recovered within 2 h of the oxidative insult. The kinetics of glutathione recovery matched the time course for the recovery of xCT cell surface expression and System xc- activity following removal of the oxidative insult. Collectively, these results suggest that oxidants acutely modulate the activity of System xc- by increasing its cell surface expression, and that this process may serve as an important mechanism to increase de novo glutathione synthesis during periods of oxidative stress.
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Affiliation(s)
- Leah A Chase
- Department of Chemistry, Hope College, Holland, MI, 49423, USA; Department of Biology, Hope College, Holland, MI, 49423, USA.
| | | | - NaTasha Schiller
- Department of Chemistry, Hope College, Holland, MI, 49423, USA; Department of Biology, Hope College, Holland, MI, 49423, USA
| | - Abby Goltz King
- Department of Chemistry, Hope College, Holland, MI, 49423, USA
| | - Guillermo Flores
- Department of Chemistry, Hope College, Holland, MI, 49423, USA; Department of Biology, Hope College, Holland, MI, 49423, USA
| | | | | | - Sara Lang Smith
- Department of Biology, Hope College, Holland, MI, 49423, USA
| | - Anne E Robinson
- Department of Chemistry, Hope College, Holland, MI, 49423, USA; Department of Biology, Hope College, Holland, MI, 49423, USA
| | - Jeffrey Rothstein
- Department of Neurology, Department of Neuroscience, Johns Hopkins University, Baltimore, MD, 21287, USA
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9
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Sowers JR, Habibi J, Aroor AR, Yang Y, Lastra G, Hill MA, Whaley-Connell A, Jaisser F, Jia G. Epithelial sodium channels in endothelial cells mediate diet-induced endothelium stiffness and impaired vascular relaxation in obese female mice. Metabolism 2019; 99:57-66. [PMID: 31302199 PMCID: PMC6901094 DOI: 10.1016/j.metabol.2019.153946] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 07/10/2019] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Mineralocorticoid receptor activation of the epithelial sodium channel in endothelial cells (ECs) (EnNaC) is accompanied by aldosterone induced endothelial stiffening and impaired nitric oxide (NO)-mediated arterial relaxation. Recent data support enhanced activity of the alpha subunit of EnNaC (αEnNaC) mediates this aldosterone induced endothelial stiffening and associated endothelial NO synthase (eNOS) activation. There is mounting evidence that diet induced obesity diminishes expression and activation of AMP-activated protein kinase α (AMPKα), sirtuin 1 (Sirt1), which would be expected to lead to impaired downstream eNOS activation. Thereby, we posited that enhanced EnNaC activation contributes to diet induced obesity related increases in stiffness of the endothelium and diminished NO mediated vascular relaxation by increasing oxidative stress and related inhibition of AMPKα, Sirt1, and associated eNOS inactivation. MATERIALS/METHODS Sixteen to twenty week-old αEnNaC knockout (αEnNaC-/-) and wild type littermate (EnNaC+/+) female mice were fed a mouse chow or an obesogenic western diet (WD) containing excess fat (46%) and fructose (17.5%) for 16 weeks. Sodium currents of ECs, endothelial stiffness and NO mediated aortic relaxation were examined along with indices of aortic oxidative stress, vascular remodeling and fibrosis. RESULTS Enhanced EnNaC activation-mediated WD-induced increases in sodium currents in isolated lung ECs, increased endothelial stiffness and impaired aortic endothelium-dependent relaxation to acetylcholine (10-9-10-4 mol/L). These abnormalities occurred in conjunction with WD-mediated aortic tissue oxidative stress, inflammation, and decreased activation of AMPKα, Sirt1, and downstream eNOS were substantially mitigated in αEnNaC-/- mice. Importantly, αEnNaC-/- prevented WD induced increases in endothelial stiffness and related impairment of endothelium-dependent relaxation as well as aortic fibrosis and remodeling. However, EnNaC signaling was not involved in diet-induced abnormal expression of adipokines and CYP11b2 in abdominal aortic perivascular adipose tissue. CONCLUSION These data suggest that endothelial specific EnNaC activation mediates WD-induced endothelial stiffness, impaired eNOS activation, aortic fibrosis and remodeling through increased aortic oxidative stress and increased inflammation related to a reduction of AMPKα and Sirt 1 mediated eNOS phosphorylation/activation and NO production.
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Affiliation(s)
- James R Sowers
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA; Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Javad Habibi
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Annayya R Aroor
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Yan Yang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA
| | - Guido Lastra
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Michael A Hill
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA; Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Adam Whaley-Connell
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Department of Medicine, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Frederic Jaisser
- INSERM, UMRS 1138, Cordeliers Research Center, Sorbonne University, USPC, Université Paris Descartes, Université Paris Diderot, F-75006 Paris, France
| | - Guanghong Jia
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA; Department of Medicine, University of Missouri School of Medicine, Columbia, MO 65212, USA.
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Bramasole L, Sinha A, Gurevich S, Radzinski M, Klein Y, Panat N, Gefen E, Rinaldi T, Jimenez-Morales D, Johnson J, Krogan NJ, Reis N, Reichmann D, Glickman MH, Pick E. Proteasome lid bridges mitochondrial stress with Cdc53/Cullin1 NEDDylation status. Redox Biol 2019; 20:533-543. [PMID: 30508698 PMCID: PMC6279957 DOI: 10.1016/j.redox.2018.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/11/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023] Open
Abstract
Cycles of Cdc53/Cullin1 rubylation (a.k.a NEDDylation) protect ubiquitin-E3 SCF (Skp1-Cullin1-F-box protein) complexes from self-destruction and play an important role in mediating the ubiquitination of key protein substrates involved in cell cycle progression, development, and survival. Cul1 rubylation is balanced by the COP9 signalosome (CSN), a multi-subunit derubylase that shows 1:1 paralogy to the 26S proteasome lid. The turnover of SCF substrates and their relevance to various diseases is well studied, yet, the extent by which environmental perturbations influence Cul1 rubylation/derubylation cycles per se is still unclear. In this study, we show that the level of cellular oxidation serves as a molecular switch, determining Cullin1 rubylation/derubylation ratio. We describe a mutant of the proteasome lid subunit, Rpn11 that exhibits accumulated levels of Cullin1-Rub1 conjugates, a characteristic phenotype of csn mutants. By dissecting between distinct phenotypes of rpn11 mutants, proteasome and mitochondria dysfunction, we were able to recognize the high reactive oxygen species (ROS) production during the transition of cells into mitochondrial respiration, as a checkpoint of Cullin1 rubylation in a reversible manner. Thus, the study adds the rubylation cascade to the list of cellular pathways regulated by redox homeostasis.
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Affiliation(s)
- L Bramasole
- Department of Human Biology, The Faculty of Natural Sciences, University of Haifa, Haifa 3190500, Israel; Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - A Sinha
- Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - S Gurevich
- Department of Biology, Technion-Israel Institute of Technology, 3200000 Haifa, Israel
| | - M Radzinski
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 9190400, Israel
| | - Y Klein
- Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - N Panat
- Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - E Gefen
- Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel
| | - T Rinaldi
- Department of Biology and Biotechnology, University of Rome ''La Sapienza'', Rome 00185, Italy
| | - D Jimenez-Morales
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - J Johnson
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - N J Krogan
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - N Reis
- Department of Biology, Technion-Israel Institute of Technology, 3200000 Haifa, Israel
| | - D Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 9190400, Israel
| | - M H Glickman
- Department of Biology, Technion-Israel Institute of Technology, 3200000 Haifa, Israel
| | - E Pick
- Department of Human Biology, The Faculty of Natural Sciences, University of Haifa, Haifa 3190500, Israel; Department of Biology and Environment, The Faculty of Natural Sciences, University of Haifa at Oranim, Tivon 3600600, Israel.
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11
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Mies F, Virreira M, Goolaerts A, Djerbib S, Beauwens R, Shlyonsky V, Boom A. DUOX1-mediated hydrogen peroxide release regulates sodium transport in H441 bronchiolar epithelial cells. Acta Physiol (Oxf) 2019; 225:e13166. [PMID: 30052308 DOI: 10.1111/apha.13166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 11/26/2022]
Abstract
AIM Dexamethasone has been shown to induce the formation of epithelial domes by bronchiolar H441 cells. It stimulates the expression of both amiloride inhibitable epithelial sodium channels (ENaC) and dual oxidase-1 (DUOX1). We therefore ask the question whether DUOX1 expression and production of submillimolar amounts of H2 O2 is instrumental for the sodium channel upregulation observed in H441 cells. METHODS In vitro cell culture, nystatin-perforated whole-cell patch-clamp technique, immunocytochemistry and RT-PCR methods have been used. RESULTS Cells forming epithelial domes induced by dexamethasone (0.1 μmol L-1 , 24 hours) and by 5-aza-2'-deoxytidine (1 μmol L-1 , 48 hours) expressed more DUOX1 protein compared with other cells in the monolayer. Dome formation could be inhibited by exogenous catalase in a concentration-dependent manner and by the NADPH oxidase inhibitor diphenyliodonium, which suggested the involvement of H2 O2 . While single application of 0.2 mmol L-1 H2 O2 induced transient dome formation, lower doses were ineffective and higher doses disrupted the cell monolayer. Hydrogen peroxide (0.1 mmol L-1 ) activated acutely amiloride-sensitive whole-cell currents from 3.91 ± 0.79 pA pF-1 to 4.76 ± 0.98 pA pF-1 in dome-forming cells and had no effect in cells outside of domes. ENaC but not DUOX1 transcription was potentiated by catalase in the presence of dexamethasone, which suggested negative feedback of H2 O2 on ENaC gene expression. CONCLUSION Our observations suggest that tonic production of H2 O2 by DUOX1 participates in maintaining the level of vectorial sodium transport by lung epithelial cells. Moreover, the system appears to be well tuned as it would allow H2 O2 -dependent innate immunity without inducing airway/alveolar sodium and fluid hyperabsorption.
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Affiliation(s)
- Frédérique Mies
- Laboratory of Physiology and Pharmacology; Université libre de Bruxelles; Brussels Belgium
| | - Myrna Virreira
- Laboratory of Cell and Molecular Physiology; Université libre de Bruxelles; Brussels Belgium
| | - Arnaud Goolaerts
- Laboratory of Physiology and Pharmacology; Université libre de Bruxelles; Brussels Belgium
| | - Sami Djerbib
- Laboratory of Cell and Molecular Physiology; Université libre de Bruxelles; Brussels Belgium
| | - Renaud Beauwens
- Laboratory of Cell and Molecular Physiology; Université libre de Bruxelles; Brussels Belgium
| | - Vadim Shlyonsky
- Laboratory of Physiology and Pharmacology; Université libre de Bruxelles; Brussels Belgium
| | - Alain Boom
- Laboratory of Cell and Molecular Physiology; Université libre de Bruxelles; Brussels Belgium
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12
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Abstract
Mucociliary clearance is critically important in protecting the airways from infection and from the harmful effects of smoke and various inspired substances known to induce oxidative stress and persistent inflammation. An essential feature of the clearance mechanism involves regulation of the periciliary liquid layer on the surface of the airway epithelium, which is necessary for normal ciliary beating and maintenance of mucus hydration. The underlying ion transport processes associated with airway surface hydration include epithelial Na+ channel-dependent Na+ absorption occurring in parallel with CFTR and Ca2+-activated Cl- channel-dependent anion secretion, which are coordinately regulated to control the depth of the periciliary liquid layer. Oxidative stress is known to cause both acute and chronic effects on airway ion transport function, and an increasing number of studies in the past few years have identified an important role for autophagy as part of the physiological response to the damaging effects of oxidation. In this review, recent studies addressing the influence of oxidative stress and autophagy on airway ion transport pathways, along with results showing the potential of autophagy modulators in restoring the function of ion channels involved in transepithelial electrolyte transport necessary for effective mucociliary clearance, are presented.
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Affiliation(s)
- Scott M O'Grady
- Departments of Animal Science, Integrative Biology and Physiology, University of Minnesota , St. Paul, Minnesota
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13
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Downs CA, Johnson NM, Coca C, Helms MN. Angiotensin II regulates δ-ENaC in human umbilical vein endothelial cells. Microvasc Res 2018; 116:26-33. [DOI: 10.1016/j.mvr.2017.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/19/2017] [Accepted: 10/15/2017] [Indexed: 11/24/2022]
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14
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Downs CA, Johnson NM, Tsaprailis G, Helms MN. RAGE-induced changes in the proteome of alveolar epithelial cells. J Proteomics 2018; 177:11-20. [PMID: 29448054 DOI: 10.1016/j.jprot.2018.02.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/28/2018] [Accepted: 02/05/2018] [Indexed: 12/14/2022]
Abstract
The receptor for advanced glycation end-products (RAGE) is a pattern recognition receptor and member of the immunoglobulin superfamily. RAGE is constitutively expressed in the distal lung where it co-localizes with the alveolar epithelium; RAGE expression is otherwise minimal or absent, except with disease. This suggests RAGE plays a role in lung physiology and pathology. We used proteomics to identify and characterize the effects of RAGE on rat alveolar epithelial (R3/1) cells. LC-MS/MS identified 177 differentially expressed proteins and the PANTHER Classification System further segregated proteins. Proteins involved in gene transcription (RNA and mRNA splicing, mRNA processing) and transport (protein, intracellular protein) were overrepresented; genes involved in a response to stimulus were underrepresented. Immune system processes and response to stimuli were downregulated with RAGE knockdown. Western blot confirmed RAGE-dependent changes in protein expression for NFκB and NLRP3 that was functionally supported by a reduction in IL-1β and phosphorylated p65. We also assessed RAGE's effect on redox regulation and report that RAGE knockdown attenuated oxidant production, decreased protein oxidation, and increased reduced thiol pools. Collectively the data suggest that RAGE is a critical regulator of epithelial cell response and has implications for our understanding of lung disease, specifically acute lung injury. SIGNIFICANCE STATEMENT In the present study, we undertook the first proteomic evaluation of RAGE-dependent processes in alveolar epithelial cells. The alveolar epithelium is a primary target during acute lung injury, and our data support a role for RAGE in gene transcription, protein transport, and response to stimuli. More over our data suggest that RAGE is a critical driver of redox regulation in the alveolar epithelium. The conclusions of the present work assist to unravel the molecular events that underlie the function of RAGE in alveolar epithelial cells and have implications for our understanding of RAGE signaling during lung injury. Our study was the first proteomic comparison showing the effects of RAGE activation from alveolar epithelial cells that constitutively express RAGE and these results can affect a wide field of lung biology, pulmonary therapeutics, and proteomics.
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Affiliation(s)
- Charles A Downs
- Biobehavioral Health Science Division, College of Nursing & Division of Translational and Regenerative Medicine, College of Medicine, The University of Arizona, Tucson, AZ, United States.
| | - Nicholle M Johnson
- Biobehavioral Health Science Division, College of Nursing & Division of Translational and Regenerative Medicine, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - George Tsaprailis
- Arizona Research Laboratories, The University of Arizona, Tucson, AZ, United States
| | - My N Helms
- Department of Internal Medicine, School of Medicine, University of Utah, Salt Lake City, UT, United States
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15
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Blobner BM, Wang XP, Kashlan OB. Conserved cysteines in the finger domain of the epithelial Na + channel α and γ subunits are proximal to the dynamic finger-thumb domain interface. J Biol Chem 2018; 293:4928-4939. [PMID: 29425099 DOI: 10.1074/jbc.m117.819367] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/26/2018] [Indexed: 11/06/2022] Open
Abstract
The epithelial Na+ channel (ENaC) is a member of the ENaC/degenerin family of ion channels. In the structure of a related family member, the "thumb" domain's base interacts with the pore, and its tip interacts with the divergent "finger" domain. Between the base and tip, the thumb domain is characterized by a conserved five-rung disulfide ladder holding together two anti-parallel α helices. The ENaC α and γ subunits' finger domains harbor autoinhibitory tracts that can be proteolytically liberated to activate the channel and also host an ENaC-specific pair of cysteines. Using a crosslinking approach, we show that one of the finger domain cysteines in the α subunit (αCys-263) and both of the finger domain cysteines in the γ subunit (γCys-213 and γCys-220) lie near the dynamic finger-thumb domain interface. Our data suggest that the αCys-256/αCys-263 pair is not disulfide-bonded. In contrast, we found that the γCys-213/γCys-220 pair is disulfide-bonded. Our data also suggest that the γ subunit lacks the terminal rung in the thumb domain disulfide ladder, suggesting asymmetry between the subunits. We also observed functional asymmetry between the α and γ subunit finger-thumb domain interfaces; crosslinks bridging the α subunit finger-thumb interface only inhibited ENaC currents, whereas crosslinks bridging the γ subunit finger-thumb interface activated or inhibited currents dependent on the length of the crosslinker. Our data suggest that reactive cysteines lie at the dynamic finger-thumb interfaces of the α and γ subunits and may play a yet undefined role in channel regulation.
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Affiliation(s)
- Brandon M Blobner
- Departments of Medicine, Renal-Electrolyte Division, Pittsburgh, Pennsylvania 15261
| | - Xue-Ping Wang
- Departments of Medicine, Renal-Electrolyte Division, Pittsburgh, Pennsylvania 15261
| | - Ossama B Kashlan
- Departments of Medicine, Renal-Electrolyte Division, Pittsburgh, Pennsylvania 15261; Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261.
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16
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Zou L, Linck V, Zhai YJ, Galarza-Paez L, Li L, Yue Q, Al-Khalili O, Bao HF, Ma HP, Thai TL, Jiao J, Eaton DC. Knockout of mitochondrial voltage-dependent anion channel type 3 increases reactive oxygen species (ROS) levels and alters renal sodium transport. J Biol Chem 2017; 293:1666-1675. [PMID: 29180450 DOI: 10.1074/jbc.m117.798645] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/27/2017] [Indexed: 11/06/2022] Open
Abstract
It has been suggested that voltage-dependent anion channels (VDACs) control the release of superoxide from mitochondria. We have previously shown that reactive oxygen species (ROS) such as superoxide (O2̇̄) and hydrogen peroxide (H2O2) stimulate epithelial sodium channels (ENaCs) in sodium-transporting epithelial tissue, including cortical collecting duct (CCD) principal cells. Therefore, we hypothesized that VDACs could regulate ENaC by modulating cytosolic ROS levels. Herein, we find that VDAC3-knockout(KO) mice can maintain normal salt and water balance on low-salt and high-salt diets. However, on a high-salt diet for 2 weeks, VDAC3-KO mice had significantly higher systolic blood pressure than wildtype mice. Consistent with this observation, after a high-salt diet for 2 weeks, ENaC activity in VDAC3-KO mice was significantly higher than wildtype mice. EM analysis disclosed a significant morphological change of mitochondria in the CCD cells of VDAC3-KO mice compared with wildtype mice, which may have been caused by mitochondrial superoxide overload. Of note, compared with wildtype animals, ROS levels in VDAC3-KO animals fed a normal or high-salt diet were consistently and significantly increased in renal tubules. Both the ROS scavenger 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine (TEMPOL) and the mitochondrial ROS scavenger (2-(2,2,6,6-tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl)triphenylphosphonium chloride (mito-TEMPO) could reverse the effect of high-salt on ENaC activity and systolic blood pressure in the VDAC3-KO mice. Mito-TEMPO partially correct the morphological changes in VDAC3-KO mice. Our results suggest that knocking out mitochondrial VDAC3 increases ROS, alters renal sodium transport, and leads to hypertension.
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Affiliation(s)
- Li Zou
- From the Department of Nephrology, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China.,the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Valerie Linck
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Yu-Jia Zhai
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Laura Galarza-Paez
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Linda Li
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Qiang Yue
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Otor Al-Khalili
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Hui-Fang Bao
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - He-Ping Ma
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Tiffany L Thai
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
| | - Jundong Jiao
- From the Department of Nephrology, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China, .,the Institute of Nephrology, Harbin Medical University, Harbin, China
| | - Douglas C Eaton
- the Department of Physiology and the Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia 30322, and
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17
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Hydrogen Peroxide and Sodium Transport in the Lung and Kidney. BIOMED RESEARCH INTERNATIONAL 2016; 2016:9512807. [PMID: 27073804 PMCID: PMC4814630 DOI: 10.1155/2016/9512807] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/04/2016] [Accepted: 03/08/2016] [Indexed: 02/07/2023]
Abstract
Renal and lung epithelial cells are exposed to some significant concentrations of H2O2. In urine it may reach 100 μM, while in the epithelial lining fluid in the lung it is estimated to be in micromolar to tens-micromolar range. Hydrogen peroxide has a stimulatory action on the epithelial sodium channel (ENaC) single-channel activity. It also increases stability of the channel at the membrane and slows down the transcription of the ENaC subunits. The expression and the activity of the channel may be inhibited in some other, likely higher, oxidative states of the cell. This review discusses the role and the origin of H2O2 in the lung and kidney. Concentration-dependent effects of hydrogen peroxide on ENaC and the mechanisms of its action have been summarized. This review also describes outlooks for future investigations linking oxidative stress, epithelial sodium transport, and lung and kidney function.
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18
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A. Downs C, A. Alli A, M. Johnson N, N. Helms M. Cigarette smoke extract is a Nox agonist and regulates ENaC in alveolar type 2 cells. AIMS MOLECULAR SCIENCE 2016. [DOI: 10.3934/molsci.2016.3.439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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19
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Inhibitory role of reactive oxygen species in the differentiation of multipotent vascular stem cells into vascular smooth muscle cells in rats: a novel aspect of traditional culture of rat aortic smooth muscle cells. Cell Tissue Res 2015; 362:97-113. [PMID: 26022334 DOI: 10.1007/s00441-015-2193-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 04/03/2015] [Indexed: 12/24/2022]
Abstract
Proliferative or synthetic vascular smooth muscle cells (VSMCs) are widely accepted to be mainly derived from the dedifferentiation or phenotypic modulation of mature contractile VSMCs, i.e., a phenotype switch from a normally quiescent and contractile type into a proliferative or synthetic form. However, this theory has been challenged by recent evidence that synthetic VSMCs predominantly originate instead from media-derived multipotent vascular stem cells (MVSCs). To test these hypotheses further, we re-examine whether the conventional rat aortic SMC (RASMC) culture involves the VSMC differentiation of MVSCs or the dedifferentiation of mature VSMCs and the potential mechanism for controlling the synthetic phenotype of RASMCs. We enzymatically isolated RASMCs and cultured the cells in both a regular growth medium (RGM) and a stem cell growth medium (SCGM). Regardless of culture conditions, only a small portion of freshly isolated RASMCs attaches, survives and grows slowly during the first 7 days of primary culture, while expressing both SMC- and MVSC-specific markers. RGM-cultured cells undergo a process of synthetic SMC differentiation, whereas SCGM-cultured cells can be differentiated into not only synthetic SMCs but also other somatic cells. Notably, compared with the RGM-cultured differentiated RASMCs, the SCGM-cultured undifferentiated cells exhibit the phenotype of MVSCs and generate greater amounts of reactive oxygen species (ROS) that act as a negative regulator of differentiation into synthetic VSMCs. Knockdown of phospholipase A2, group 7 (Pla2g7) suppresses ROS formation in the MVSCs while enhancing SMC differentiation of MVSCs. These results suggest that cultured synthetic VSMCs can be derived from the SMC differentiation of MVSCs with ROS as a negative regulator.
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20
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Downs CA, Kreiner L, Zhao XM, Trac P, Johnson NM, Hansen JM, Brown LA, Helms MN. Oxidized glutathione (GSSG) inhibits epithelial sodium channel activity in primary alveolar epithelial cells. Am J Physiol Lung Cell Mol Physiol 2015; 308:L943-52. [PMID: 25713321 PMCID: PMC4888545 DOI: 10.1152/ajplung.00213.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 02/15/2015] [Indexed: 11/22/2022] Open
Abstract
Amiloride-sensitive epithelial Na(+) channels (ENaC) regulate fluid balance in the alveoli and are regulated by oxidative stress. Since glutathione (GSH) is the predominant antioxidant in the lungs, we proposed that changes in glutathione redox potential (Eh) would alter cell signaling and have an effect on ENaC open probability (Po). In the present study, we used single channel patch-clamp recordings to examine the effect of oxidative stress, via direct application of glutathione disulfide (GSSG), on ENaC activity. We found a linear decrease in ENaC activity as the GSH/GSSG Eh became less negative (n = 21; P < 0.05). Treatment of 400 μM GSSG to the cell bath significantly decreased ENaC Po from 0.39 ± 0.06 to 0.13 ± 0.05 (n = 8; P < 0.05). Likewise, back-filling recording electrodes with 400 μM GSSG reduced ENaC Po from 0.32 ± 0.08 to 0.17 ± 0.05 (n = 10; P < 0.05), thus implicating GSSG as an important regulatory factor. Biochemical assays indicated that oxidizing potentials promote S-glutathionylation of ENaC and irreversible oxidation of cysteine residues with N-ethylmaleimide blocked the effects of GSSG on ENaC Po. Additionally, real-time imaging studies showed that GSSG impairs alveolar fluid clearance in vivo as opposed to GSH, which did not impair clearance. Taken together, these data show that glutathione Eh is an important determinant of alveolar fluid clearance in vivo.
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Affiliation(s)
- Charles A Downs
- Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia
| | - Lisa Kreiner
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia
| | - Xing-Ming Zhao
- Department of Computer Science, School of Electronics and Information Engineering, Tongji University, Shanghai, China
| | - Phi Trac
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia
| | - Nicholle M Johnson
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia
| | - Jason M Hansen
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia; Center for Cystic Fibrosis and Airways Disease Research at Children's Healthcare of Atlanta Hospital, Atlanta, Georgia; and
| | - Lou Ann Brown
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia; Center for Cystic Fibrosis and Airways Disease Research at Children's Healthcare of Atlanta Hospital, Atlanta, Georgia; and
| | - My N Helms
- Department Pediatrics, School of Medicine, Emory University, Atlanta, Georgia; Center for Cystic Fibrosis and Airways Disease Research at Children's Healthcare of Atlanta Hospital, Atlanta, Georgia; and
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21
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Downs CA, Kreiner LH, Johnson NM, Brown LA, Helms MN. Receptor for advanced glycation end-products regulates lung fluid balance via protein kinase C-gp91(phox) signaling to epithelial sodium channels. Am J Respir Cell Mol Biol 2015; 52:75-87. [PMID: 24978055 DOI: 10.1165/rcmb.2014-0002oc] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The receptor for advanced glycation end-products (RAGE), a multiligand member of the Ig family, may play a crucial role in the regulation of lung fluid balance. We quantified soluble RAGE (sRAGE), a decoy isoform, and advanced glycation end-products (AGEs) from the bronchoalveolar lavage fluid of smokers and nonsmokers, and tested the hypothesis that AGEs regulate lung fluid balance through protein kinase C (PKC)-gp91(phox) signaling to the epithelial sodium channel (ENaC). Human bronchoalveolar lavage samples from smokers showed increased AGEs (9.02 ± 3.03 μg versus 2.48 ± 0.53 μg), lower sRAGE (1,205 ± 292 pg/ml versus 1,910 ± 263 pg/ml), and lower volume(s) of epithelial lining fluid (97 ± 14 ml versus 133 ± 17 ml). sRAGE levels did not predict ELF volumes in nonsmokers; however, in smokers, higher volumes of ELF were predicted with higher levels of sRAGE. Single-channel patch clamp analysis of rat alveolar epithelial type 1 cells showed that AGEs increased ENaC activity measured as the product of the number of channels (N) and the open probability (Po) (NPo) from 0.19 ± 0.08 to 0.83 ± 0.22 (P = 0.017) and the subsequent addition of 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-N-oxyl decreased ENaC NPo to 0.15 ± 0.07 (P = 0.01). In type 2 cells, human AGEs increased ENaC NPo from 0.12 ± 0.05 to 0.53 ± 0.16 (P = 0.025) and the addition of 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-N-oxyl decreased ENaC NPo to 0.10 ± 0.03 (P = 0.013). Using molecular and biochemical techniques, we observed that inhibition of RAGE and PKC activity attenuated AGE-induced activation of ENaC. AGEs induced phosphorylation of p47(phox) and increased gp91(phox)-dependent reactive oxygen species production, a response that was abrogated with RAGE or PKC inhibition. Finally, tracheal instillation of AGEs promoted clearance of lung fluid, whereas concomitant inhibition of RAGE, PKC, and gp91(phox) abrogated the response.
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22
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Ivonnet P, Salathe M, Conner GE. Hydrogen peroxide stimulation of CFTR reveals an Epac-mediated, soluble AC-dependent cAMP amplification pathway common to GPCR signalling. Br J Pharmacol 2014; 172:173-84. [PMID: 25220136 DOI: 10.1111/bph.12934] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 08/27/2014] [Accepted: 09/03/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE H2 O2 is widely understood to regulate intracellular signalling. In airway epithelia, H2 O2 stimulates anion secretion primarily by activating an autocrine PGE2 signalling pathway via EP4 and EP1 receptors to initiate cytic fibrosis transmembrane regulator (CFTR)-mediated Cl(-) secretion. This study investigated signalling downstream of the receptors activated by H2 O2 . EXPERIMENTAL APPROACH Anion secretion by differentiated bronchial epithelial cells was measured in Ussing chambers during stimulation with H2 O2 , an EP4 receptor agonist or β2 -adrenoceptor agonist in the presence and absence of inhibitors of ACs and downstream effectors. Intracellular calcium ([Ca(2+) ]I ) changes were followed by microscopy using fura-2-loaded cells and PKA activation followed by FRET microscopy. KEY RESULTS Transmembrane adenylyl cyclase (tmAC) and soluble AC (sAC) were both necessary for H2 O2 and EP4 receptor-mediated CFTR activation in bronchial epithelia. H2 O2 and EP4 receptor agonist stimulated tmAC to increase exchange protein activated by cAMP (Epac) activity that drives PLC activation to raise [Ca(2+) ]i via Ca(2+) store release (and not entry). Increased [Ca(2+) ]i led to sAC activation and further increases in CFTR activity. Stimulation of sAC did not depend on changes in [HCO3 (-) ]. Ca(2+) -activated apical KCa 1.1 channels and cAMP-activated basolateral KV 7.1 channels contributed to H2 O2 -stimulated anion currents. A similar Epac-mediated pathway was seen following β2 -adrenoceptor or forskolin stimulation. CONCLUSIONS AND IMPLICATIONS H2 O2 initiated a complex signalling cascade that used direct stimulation of tmACs by Gαs followed by Epac-mediated Ca(2+) crosstalk to activate sAC. The Epac-mediated Ca(2+) signal constituted a positive feedback loop that amplified CFTR anion secretion following stimulation of tmAC by a variety of stimuli.
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Affiliation(s)
- P Ivonnet
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, University of Miami, Miami, Florida, USA
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23
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Cowley AW, Abe M, Mori T, O'Connor PM, Ohsaki Y, Zheleznova NN. Reactive oxygen species as important determinants of medullary flow, sodium excretion, and hypertension. Am J Physiol Renal Physiol 2014; 308:F179-97. [PMID: 25354941 DOI: 10.1152/ajprenal.00455.2014] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The physiological evidence linking the production of superoxide, hydrogen peroxide, and nitric oxide in the renal medullary thick ascending limb of Henle (mTAL) to regulation of medullary blood flow, sodium homeostasis, and long-term control of blood pressure is summarized in this review. Data obtained largely from rats indicate that experimentally induced elevations of either superoxide or hydrogen peroxide in the renal medulla result in reduction of medullary blood flow, enhanced Na(+) reabsorption, and hypertension. A shift in the redox balance between nitric oxide and reactive oxygen species (ROS) is found to occur naturally in the Dahl salt-sensitive (SS) rat model, where selective reduction of ROS production in the renal medulla reduces salt-induced hypertension. Excess medullary production of ROS in SS rats emanates from the medullary thick ascending limbs of Henle [from both the mitochondria and membrane NAD(P)H oxidases] in response to increased delivery and reabsorption of excess sodium and water. There is evidence that ROS and perhaps other mediators such as ATP diffuse from the mTAL to surrounding vasa recta capillaries, resulting in medullary ischemia, which thereby contributes to hypertension.
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Affiliation(s)
- Allen W Cowley
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Michiaki Abe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Takefumi Mori
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Paul M O'Connor
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Yusuke Ohsaki
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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24
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Helms MN, Trac P. ERp29, a chaperone protein ushering in new insights on ion transport regulation. Focus on "ERp29 regulates epithelial sodium channel functional expression by promoting channel cleavage". Am J Physiol Cell Physiol 2014; 307:C699-700. [PMID: 25009112 DOI: 10.1152/ajpcell.00217.2014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- My N Helms
- Department of Pediatrics and Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
| | - Phi Trac
- Department of Pediatrics and Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
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25
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Ronzaud C, Staub O. Ubiquitylation and control of renal Na+ balance and blood pressure. Physiology (Bethesda) 2014; 29:16-26. [PMID: 24382868 DOI: 10.1152/physiol.00021.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ubiquitylation is crucial for regulating numerous cellular functions. In the kidney, ubiquitylation regulates the epithelial Na(+) channel ENaC. The importance of this process is highlighted in Liddle's syndrome, where mutations interfere with ENaC ubiquitylation, resulting in constitutive Na(+) reabsorption and hypertension. There is emerging evidence that NCC, involved in hypertensive diseases, is also regulated by ubiquitylation. Here, we discuss the current knowledge and recent findings in this field.
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Affiliation(s)
- Caroline Ronzaud
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
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26
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Pavlov TS, Levchenko V, Staruschenko A. Role of Rho GDP dissociation inhibitor α in control of epithelial sodium channel (ENaC)-mediated sodium reabsorption. J Biol Chem 2014; 289:28651-9. [PMID: 25164814 DOI: 10.1074/jbc.m114.558262] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The epithelial sodium channel (ENaC) is expressed in the aldosterone-sensitive distal nephron where it performs sodium reabsorption from the lumen. We have recently shown that ENaC activity contributes to the development of salt-induced hypertension as a result of deficiency of EGF level. Previous studies revealed that Rho GDP-dissociation inhibitor α (RhoGDIα) is involved in the control of salt-sensitive hypertension and renal injury via Rac1, which is one of the small GTPases activating ENaC. Here we investigated the intracellular mechanism mediating the involvement of the RhoGDIα/Rac1 axis in the control of ENaC and the effect of EGF on ENaC in this pathway. We demonstrated that RhoGDIα is highly expressed in the cortical collecting ducts of mice and rats, and its expression is down-regulated in Dahl salt-sensitive rats fed a high salt diet. Knockdown of RhoGDIα in cultured cortical collecting duct principal cells increased ENaC subunits expression and ENaC-mediated sodium reabsorption. Furthermore, RhoGDIα deficiency causes enhanced response to EGF treatment. Patch clamp analysis reveals that RhoGDIα significantly decreases ENaC current density and prevents its up-regulation by RhoA and Rac1. Inhibition of Rho kinase with Y27632 had no effects on ENaC response to EGF either in control or RhoGDIα knocked down cells. However, EGF treatment increased levels of active Rac1, which was further enhanced in RhoGDIα-deficient cells. We conclude that changes in the RhoGDIα-dependent pathway have a permissive role in the Rac1-mediated enhancement of ENaC activity observed in salt-induced hypertension.
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Affiliation(s)
- Tengis S Pavlov
- From the Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Vladislav Levchenko
- From the Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Alexander Staruschenko
- From the Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
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27
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Gammon ST, Foje N, Brewer EM, Owers E, Downs CA, Budde MD, Leevy WM, Helms MN. Preclinical anatomical, molecular, and functional imaging of the lung with multiple modalities. Am J Physiol Lung Cell Mol Physiol 2014; 306:L897-914. [DOI: 10.1152/ajplung.00007.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In vivo imaging is an important tool for preclinical studies of lung function and disease. The widespread availability of multimodal animal imaging systems and the rapid rate of diagnostic contrast agent development have empowered researchers to noninvasively study lung function and pulmonary disorders. Investigators can identify, track, and quantify biological processes over time. In this review, we highlight the fundamental principles of bioluminescence, fluorescence, planar X-ray, X-ray computed tomography, magnetic resonance imaging, and nuclear imaging modalities (such as positron emission tomography and single photon emission computed tomography) that have been successfully employed for the study of lung function and pulmonary disorders in a preclinical setting. The major principles, benefits, and applications of each imaging modality and technology are reviewed. Limitations and the future prospective of multimodal imaging in pulmonary physiology are also discussed. In vivo imaging bridges molecular biological studies, drug design and discovery, and the imaging field with modern medical practice, and, as such, will continue to be a mainstay in biomedical research.
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Affiliation(s)
- Seth T. Gammon
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Nathan Foje
- Department of Biological Sciences, Notre Dame Integrated Imaging Facility, Notre Dame, Indiana
| | - Elizabeth M. Brewer
- Department of Pediatrics Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
| | - Elizabeth Owers
- Department of Biological Sciences, Notre Dame Integrated Imaging Facility, Notre Dame, Indiana
| | - Charles A. Downs
- Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia; and
| | - Matthew D. Budde
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - W. Matthew Leevy
- Department of Biological Sciences, Notre Dame Integrated Imaging Facility, Notre Dame, Indiana
| | - My N. Helms
- Department of Pediatrics Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
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28
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Ward JBJ, Keely SJ, Keely SJ. Oxygen in the regulation of intestinal epithelial transport. J Physiol 2014; 592:2473-89. [PMID: 24710059 DOI: 10.1113/jphysiol.2013.270249] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The transport of fluid, nutrients and electrolytes to and from the intestinal lumen is a primary function of epithelial cells. Normally, the intestine absorbs approximately 9 l of fluid and 1 kg of nutrients daily, driven by epithelial transport processes that consume large amounts of cellular energy and O2. The epithelium exists at the interface of the richly vascularised mucosa, and the anoxic luminal environment and this steep O2 gradient play a key role in determining the expression pattern of proteins involved in fluid, nutrient and electrolyte transport. However, the dynamic nature of the splanchnic circulation necessitates that the epithelium can evoke co-ordinated responses to fluctuations in O2 availability, which occur either as a part of the normal digestive process or as a consequence of several pathophysiological conditions. While it is known that hypoxia-responsive signals, such as reactive oxygen species, AMP-activated kinase, hypoxia-inducible factors, and prolyl hydroxylases are all important in regulating epithelial responses to altered O2 supply, our understanding of the molecular mechanisms involved is still limited. Here, we aim to review the current literature regarding the role that O2 plays in regulating intestinal transport processes and to highlight areas of research that still need to be addressed.
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Affiliation(s)
- Joseph B J Ward
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Simon J Keely
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle NSW, Australia
| | - Stephen J Keely
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
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29
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Alli AA, Brewer EM, Montgomery DS, Ghant MS, Eaton DC, Brown LA, Helms MN. Chronic ethanol exposure alters the lung proteome and leads to mitochondrial dysfunction in alveolar type 2 cells. Am J Physiol Lung Cell Mol Physiol 2014; 306:L1026-35. [PMID: 24682449 DOI: 10.1152/ajplung.00287.2013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The lungs can undergo irreversible damage from chronic alcohol consumption. Herein, we developed an animal model predisposed for edematous lung injury following chronic ingestion of alcohol to better understand the etiology of alcohol-related disorders. Using animal modeling, alongside high-throughput proteomic and microarray assays, we identified changes in lung protein and transcript in mice and rats, respectively, following chronic alcohol ingestion or a caloric control diet. Liquid chromatography-mass spectrometry identified several mitochondrial-related proteins in which the expression was upregulated following long-term alcohol ingestion in mice. Consistent with these observations, rat gene chip microarray analysis of alveolar cells obtained from animals maintained on a Lieber-DeCarli liquid alcohol diet confirmed significant changes in mitochondrial-related transcripts in the alcohol lung. Transmission electron microscopy revealed significant changes in the mitochondrial architecture in alcohol mice, particularly following lipopolysaccharide exposure. Chronic alcohol ingestion was also shown to worsen mitochondrial respiration, mitochondrial membrane polarization, and NAD(+)-to-NADH ratios in alveolar type 2 cells. In summary, our studies show causal connection between chronic alcohol ingestion and mitochondrial dysfunction, albeit the specific role of each of the mitochondrial-related proteins and transcripts identified in our study requires additional study.
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Affiliation(s)
- Abdel A Alli
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Elizabeth M Brewer
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia; and
| | | | - Marcus S Ghant
- Department of Biological Sciences, Clark Atlanta University, Atlanta, Georgia
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia; Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia; and
| | - Lou Ann Brown
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia; and
| | - My N Helms
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia; Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia; and
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30
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TGF-β directs trafficking of the epithelial sodium channel ENaC which has implications for ion and fluid transport in acute lung injury. Proc Natl Acad Sci U S A 2013; 111:E374-83. [PMID: 24324142 DOI: 10.1073/pnas.1306798111] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
TGF-β is a pathogenic factor in patients with acute respiratory distress syndrome (ARDS), a condition characterized by alveolar edema. A unique TGF-β pathway is described, which rapidly promoted internalization of the αβγ epithelial sodium channel (ENaC) complex from the alveolar epithelial cell surface, leading to persistence of pulmonary edema. TGF-β applied to the alveolar airspaces of live rabbits or isolated rabbit lungs blocked sodium transport and caused fluid retention, which--together with patch-clamp and flow cytometry studies--identified ENaC as the target of TGF-β. TGF-β rapidly and sequentially activated phospholipase D1, phosphatidylinositol-4-phosphate 5-kinase 1α, and NADPH oxidase 4 (NOX4) to produce reactive oxygen species, driving internalization of βENaC, the subunit responsible for cell-surface stability of the αβγENaC complex. ENaC internalization was dependent on oxidation of βENaC Cys(43). Treatment of alveolar epithelial cells with bronchoalveolar lavage fluids from ARDS patients drove βENaC internalization, which was inhibited by a TGF-β neutralizing antibody and a Tgfbr1 inhibitor. Pharmacological inhibition of TGF-β signaling in vivo in mice, and genetic ablation of the nox4 gene in mice, protected against perturbed lung fluid balance in a bleomycin model of lung injury, highlighting a role for both proximal and distal components of this unique ENaC regulatory pathway in lung fluid balance. These data describe a unique TGF-β-dependent mechanism that regulates ion and fluid transport in the lung, which is not only relevant to the pathological mechanisms of ARDS, but might also represent a physiological means of acutely regulating ENaC activity in the lung and other organs.
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31
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Downs CA, Kreiner LH, Trac DQ, Helms MN. Acute effects of cigarette smoke extract on alveolar epithelial sodium channel activity and lung fluid clearance. Am J Respir Cell Mol Biol 2013; 49:251-9. [PMID: 23526224 DOI: 10.1165/rcmb.2012-0234oc] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cigarette smoke contains high levels of reactive species. Moreover, cigarette smoke can induce cellular production of oxidants. The purpose of this study was to determine the effect of cigarette smoke extract (CSE)-derived oxidants on epithelial sodium channel (ENaC) activity in alveolar type 1 (T1) and type 2 (T2) cells and to measure corresponding rates of fluid clearance in mice receiving a tracheal instillation of CSE. Single-channel patch clamp analysis of T1 and T2 cells demonstrate that CSE exposure increases ENaC activity (NPo), measured as the product of the number of channels (N) and a channels open probability (Po), from 0.17 ± 0.07 to 0.34 ± 0.10 (n = 9; P = 0.04) in T1 cells. In T2 cells, CSE increased NPo from 0.08 ± 0.03 to 0.35 ± 0.10 (n = 9; P = 0.02). In both cell types, addition of tetramethylpiperidine and glutathione attenuated CSE-induced increases in ENaC NPo. Biotinylation and cycloheximide chase assays indicate that CSE-derived ROS increases channel activity, in part, by maintaining cell surface expression of the α-ENaC subunit. In vivo studies show that tracheal instillation of CSE promoted alveolar fluid clearance after 105 minutes compared with vehicle control (n = 10/group; P < 0.05).
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Affiliation(s)
- Charles A Downs
- Nell Hodgson Woodruff School of Nursing, School of Medicine, Emory University, Atlanta, GA 30322, USA
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32
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L Y K, McIntosh CJ, Biasio W, Liu Y, Ke Y, Olson DR, Miller JH, Page R, Snyder PM, McDonald FJ. Regulation of the delta and alpha epithelial sodium channel (ENaC) by ubiquitination and Nedd8. J Cell Physiol 2013; 228:2190-201. [PMID: 23589227 DOI: 10.1002/jcp.24390] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 04/05/2013] [Indexed: 12/16/2022]
Abstract
The δ epithelial sodium channel (δENaC) is a proton-activated, sodium-selective, amiloride-sensitive ion channel in the ENaC/degenerin family of ion channels involved in blood pressure regulation and mechanosensation. Other ENaC family members are subject to ubiquitin modification leading to internalization from the cell surface, and degradation of the channel. Here, we show that δENaC is also modified by ubiquitin on three intracellular lysine residues. Absence of these lysines abolished ubiquitin modification of δENaC and increased cell surface levels of δENaC. Although the HECT-domain ubiquitin ligase Nedd4-2 reduced amiloride-sensitive current generated by δβγENaC-containing channels, δENaC does not contain a binding site for Nedd4-2; therefore, this effect is probably mediated by the βγENaC subunits. Nedd8, a ubiquitin-like protein that regulates RING-domain E3 ubiquitin ligases, promoted δENaC ubiquitination, decreased both the intracellular and cell surface δENaC populations, and decreased δβγENaC amiloride-sensitive short circuit current (Isc -amiloride) in a mammalian epithelium. Nedd8 also promoted α- and γENaC ubiquitination, decreased the cell surface pools, and decreased αβγENaC Isc -amiloride. Conversely, XIAP, a single subunit RING E3 ligase, decreased ubiquitinated δENaC, increased the δENaC cell surface pool and increased δβγENaC Isc -amiloride. Therefore δ- and α - βγENaC channel function may be influenced by RING-domain E3 ubiquitin ligases.
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Affiliation(s)
- Kevin L Y
- Department of Physiology, University of Otago, Dunedin, New Zealand
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Abstract
Ion channels perform a variety of cellular functions in lung epithelia. Oxidant- and antioxidant-mediated mechanisms (that is, redox regulation) of ion channels are areas of intense research. Significant progress has been made in our understanding of redox regulation of ion channels since the last Experimental Biology report in 2003. Advancements include: 1) identification of nonphagocytic NADPH oxidases as sources of regulated reactive species (RS) production in epithelia, 2) an understanding that excessive treatment with antioxidants can result in greater oxidative stress, and 3) characterization of novel RS signaling pathways that converge upon ion channel regulation. These advancements, as discussed at the 2013 Experimental Biology Meeting in Boston, MA, impact our understanding of oxidative stress in the lung, and, in particular, illustrate that the redox state has profound effects on ion channel and cellular function.
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34
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Staruschenko A, Palygin O, Ilatovskaya DV, Pavlov TS. Epidermal growth factors in the kidney and relationship to hypertension. Am J Physiol Renal Physiol 2013; 305:F12-20. [PMID: 23637204 DOI: 10.1152/ajprenal.00112.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Members of the epidermal growth factor (EGF)-family bind to ErbB (EGFR)-family receptors that play an important role in the regulation of various fundamental cell processes in many organs including the kidney. In this field, most of the research efforts are focused on the role of EGF-ErbB axis in cancer biology. However, many studies indicate that abnormal ErbB-mediated signaling pathways are critical in the development of renal and cardiovascular pathologies. The kidney is a major site of the EGF-family ligands synthesis, and it has been shown to express all four members of the ErbB receptor family. The study of kidney disease regulation by ErbB receptor ligands has expanded considerably in recent years. In vitro and in vivo studies have provided direct evidence of the role of ErbB signaling in the kidney. Recent advances in the understanding of how the proteins in the EGF-family regulate sodium transport and development of hypertension are specifically discussed here. Collectively, these results suggest that EGF-ErbB signaling pathways could be major determinants in the progress of renal lesions, including its effects on the regulation of sodium reabsorption in collecting ducts.
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Affiliation(s)
- Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA.
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