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Gao Y, Cao F, Tian X, Zhang Q, Xu C, Ji B, Zhang YA, Du L, Han J, Li L, Zhou S, Gong Y, Ying B, Gao-Smith F, Jin S. Inhibition the ubiquitination of ENaC and Na,K-ATPase with erythropoietin promotes alveolar fluid clearance in sepsis-induced acute respiratory distress syndrome. Biomed Pharmacother 2024; 174:116447. [PMID: 38518606 DOI: 10.1016/j.biopha.2024.116447] [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: 01/01/2024] [Revised: 03/08/2024] [Accepted: 03/15/2024] [Indexed: 03/24/2024] Open
Abstract
Sepsis-induced acute respiratory distress syndrome (ARDS) causes significant fatalities worldwide and lacks pharmacological intervention. Alveolar fluid clearance (AFC) plays a pivotal role in the remission of ARDS and is markedly impaired in the pathogenesis of ARDS. Here, we demonstrated that erythropoietin could effectively ameliorate lung injury manifestations and lethality, restore lung function and promote AFC in a rat model of lipopolysaccharide (LPS)-induced ARDS. Moreover, it was proven that EPO-induced restoration of AFC occurs through triggering the total protein expression of ENaC and Na,K-ATPase channels, enhancing their protein abundance in the membrane, and suppressing their ubiquitination for degeneration. Mechanistically, the data indicated the possible involvement of EPOR/JAK2/STAT3/SGK1/Nedd4-2 signaling in this process, and the pharmacological inhibition of the pathway markedly eliminated the stimulating effects of EPO on ENaC and Na,K-ATPase, and subsequently reversed the augmentation of AFC by EPO. Consistently, in vitro studies of alveolar epithelial cells paralleled with that EPO upregulated the expression of ENaC and Na,K-ATPase, and patch-clamp studies further demonstrated that EPO substantially strengthened sodium ion currents. Collectively, EPO could effectively promote AFC by improving ENaC and Na,K-ATPase protein expression and abundance in the membrane, dependent on inhibition of ENaC and Na,K-ATPase ubiquitination, and resulting in diminishing LPS-associated lung injuries.
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Affiliation(s)
- Ye Gao
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Fei Cao
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China; Department of Anesthesiology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xinyi Tian
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Qianping Zhang
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Congcong Xu
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Bowen Ji
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Ye-An Zhang
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Linan Du
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Jun Han
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Li Li
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Siyu Zhou
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Yuqiang Gong
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Binyu Ying
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Fang Gao-Smith
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China; Centre for Translational Inflammation Research, Institute of Inflammation and Aging, University of Birmingham, Birmingham, United Kingdom.
| | - Shengwei Jin
- Department of Anaesthesia, Pain and Critical Care, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China; Key Laboratory of Pediatric Anesthesiology, Ministry of Education, Wenzhou Medical University, Zhejiang, China; Laboratory of Anesthesiology of Zhejiang Province, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China.
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A Naveena H, Bhatia D. Hypoxia Modulates Cellular Endocytic Pathways and Organelles with Enhanced Cell Migration and 3D Cell Invasion. Chembiochem 2023; 24:e202300506. [PMID: 37677117 DOI: 10.1002/cbic.202300506] [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: 07/11/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 09/09/2023]
Abstract
Hypoxia, a decrease in cellular or tissue level oxygen content, is characteristic of most tumors and has been shown to drive cancer progression by altering multiple subcellular processes. We hypothesized that the cancer cells in a hypoxic environment might have slower proliferation rates and increased invasion and migration rates with altered endocytosis compared to the cancer cells in the periphery of the tumor mass that experience normoxic conditions. We induced cellular hypoxia by exposing cells to cobalt chloride, a chemical hypoxic mimicking agent. This study measured the effect of hypoxia on cell proliferation, migration, and invasion. Uptake of fluorescently labeled transferrin, galectin3, and dextran that undergo endocytosis through major endocytic pathways (Clathrin-mediated pathway (CME), Clathrin-independent pathway (CIE), Fluid phase endocytosis (FPE)) were analyzed during hypoxia. Also, the organelle changes associated with hypoxia were studied with organelle trackers. We found that the proliferation rate decreased, and the migration and invasion rate increased in cancer cells in hypoxic conditions compared to normoxic cancer cells. A short hypoxic exposure increased galectin3 uptake in hypoxic cancer cells, but a prolonged hypoxic exposure decreased clathrin-independent endocytic uptake of galectin 3. Subcellular organelles, such as mitochondria, increased to withstand the hypoxic stress, while other organelles, such as Endoplasmic reticulum (ER), were significantly decreased. These data suggest that hypoxia modulates cellular endocytic pathways with reduced proliferation and enhanced cell migration and invasion.
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Affiliation(s)
- Hema A Naveena
- Biological Engineering Discipline, Indian Institute of Technology Gandhinagar, Palaj Gandhinagar, 382355, Gujarat, India
| | - Dhiraj Bhatia
- Biological Engineering Discipline, Indian Institute of Technology Gandhinagar, Palaj Gandhinagar, 382355, Gujarat, India
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Mikami Y, Grubb BR, Rogers TD, Dang H, Asakura T, Kota P, Gilmore RC, Okuda K, Morton LC, Sun L, Chen G, Wykoff JA, Ehre C, Vilar J, van Heusden C, Livraghi-Butrico A, Gentzsch M, Button B, Stutts MJ, Randell SH, O’Neal WK, Boucher RC. Chronic airway epithelial hypoxia exacerbates injury in muco-obstructive lung disease through mucus hyperconcentration. Sci Transl Med 2023; 15:eabo7728. [PMID: 37285404 PMCID: PMC10664029 DOI: 10.1126/scitranslmed.abo7728] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 05/17/2023] [Indexed: 06/09/2023]
Abstract
Unlike solid organs, human airway epithelia derive their oxygen from inspired air rather than the vasculature. Many pulmonary diseases are associated with intraluminal airway obstruction caused by aspirated foreign bodies, virus infection, tumors, or mucus plugs intrinsic to airway disease, including cystic fibrosis (CF). Consistent with requirements for luminal O2, airway epithelia surrounding mucus plugs in chronic obstructive pulmonary disease (COPD) lungs are hypoxic. Despite these observations, the effects of chronic hypoxia (CH) on airway epithelial host defense functions relevant to pulmonary disease have not been investigated. Molecular characterization of resected human lungs from individuals with a spectrum of muco-obstructive lung diseases (MOLDs) or COVID-19 identified molecular features of chronic hypoxia, including increased EGLN3 expression, in epithelia lining mucus-obstructed airways. In vitro experiments using cultured chronically hypoxic airway epithelia revealed conversion to a glycolytic metabolic state with maintenance of cellular architecture. Chronically hypoxic airway epithelia unexpectedly exhibited increased MUC5B mucin production and increased transepithelial Na+ and fluid absorption mediated by HIF1α/HIF2α-dependent up-regulation of β and γENaC (epithelial Na+ channel) subunit expression. The combination of increased Na+ absorption and MUC5B production generated hyperconcentrated mucus predicted to perpetuate obstruction. Single-cell and bulk RNA sequencing analyses of chronically hypoxic cultured airway epithelia revealed transcriptional changes involved in airway wall remodeling, destruction, and angiogenesis. These results were confirmed by RNA-in situ hybridization studies of lungs from individuals with MOLD. Our data suggest that chronic airway epithelial hypoxia may be central to the pathogenesis of persistent mucus accumulation in MOLDs and associated airway wall damage.
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Affiliation(s)
- Yu Mikami
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Barbara R. Grubb
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Troy D. Rogers
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Hong Dang
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Takanori Asakura
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Pradeep Kota
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Rodney C. Gilmore
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Kenichi Okuda
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Lisa C. Morton
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Ling Sun
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Gang Chen
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jason A. Wykoff
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Juan Vilar
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Catharina van Heusden
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | | | - Martina Gentzsch
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Brian Button
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - M. Jackson Stutts
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Scott H. Randell
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Wanda K. O’Neal
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Richard C. Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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Zhou W, Hou Y, Yu T, Wang T, Ding Y, Nie H. Submersion and hypoxia inhibit alveolar epithelial Na + transport through ERK/NF-κB signaling pathway. Respir Res 2023; 24:117. [PMID: 37095538 PMCID: PMC10127099 DOI: 10.1186/s12931-023-02428-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 04/19/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND Hypoxia is associated with many respiratory diseases, partly due to the accumulation of edema fluid and mucus on the surface of alveolar epithelial cell (AEC), which forms oxygen delivery barriers and is responsible for the disruption of ion transport. Epithelial sodium channel (ENaC) on the apical side of AEC plays a crucial role to maintain the electrochemical gradient of Na+ and water reabsorption, thus becomes the key point for edema fluid removal under hypoxia. Here we sought to explore the effects of hypoxia on ENaC expression and the further mechanism related, which may provide a possible treatment strategy in edema related pulmonary diseases. METHODS Excess volume of culture medium was added on the surface of AEC to simulate the hypoxic environment of alveoli in the state of pulmonary edema, supported by the evidence of increased hypoxia-inducible factor-1 expression. The protein/mRNA expressions of ENaC were detected, and extracellular signal-regulated kinase (ERK)/nuclear factor κB (NF-κB) inhibitor was applied to explore the detailed mechanism about the effects of hypoxia on epithelial ion transport in AEC. Meanwhile, mice were placed in chambers with normoxic or hypoxic (8%) condition for 24 h, respectively. The effects of hypoxia and NF-κB were assessed through alveolar fluid clearance and ENaC function by Ussing chamber assay. RESULTS Hypoxia (submersion culture mode) induced the reduction of protein/mRNA expression of ENaC, whereas increased the activation of ERK/NF-κB signaling pathway in parallel experiments using human A549 and mouse alveolar type 2 cells, respectively. Moreover, the inhibition of ERK (PD98059, 10 µM) alleviated the phosphorylation of IκB and p65, implying NF-κB as a downstream pathway involved with ERK regulation. Intriguingly, the expression of α-ENaC could be reversed by either ERK or NF-κB inhibitor (QNZ, 100 nM) under hypoxia. The alleviation of pulmonary edema was evidenced by the administration of NF-κB inhibitor, and enhancement of ENaC function was supported by recording amiloride-sensitive short-circuit currents. CONCLUSIONS The expression of ENaC was downregulated under hypoxia induced by submersion culture, which may be mediated by ERK/NF-κB signaling pathway.
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Affiliation(s)
- Wei Zhou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yapeng Hou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Tong Yu
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Tingyu Wang
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yan Ding
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China.
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5
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Wong SL, Kardia E, Vijayan A, Umashankar B, Pandzic E, Zhong L, Jaffe A, Waters SA. Molecular and Functional Characteristics of Airway Epithelium under Chronic Hypoxia. Int J Mol Sci 2023; 24:ijms24076475. [PMID: 37047450 PMCID: PMC10095024 DOI: 10.3390/ijms24076475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 04/14/2023] Open
Abstract
Localized and chronic hypoxia of airway mucosa is a common feature of progressive respiratory diseases, including cystic fibrosis (CF). However, the impact of prolonged hypoxia on airway stem cell function and differentiated epithelium is not well elucidated. Acute hypoxia alters the transcription and translation of many genes, including the CF transmembrane conductance regulator (CFTR). CFTR-targeted therapies (modulators) have not been investigated in vitro under chronic hypoxic conditions found in CF airways in vivo. Nasal epithelial cells (hNECs) derived from eight CF and three non-CF participants were expanded and differentiated at the air-liquid interface (26-30 days) at ambient and 2% oxygen tension (hypoxia). Morphology, global proteomics (LC-MS/MS) and function (barrier integrity, cilia motility and ion transport) of basal stem cells and differentiated cultures were assessed. hNECs expanded at chronic hypoxia, demonstrating epithelial cobblestone morphology and a similar proliferation rate to hNECs expanded at normoxia. Hypoxia-inducible proteins and pathways in stem cells and differentiated cultures were identified. Despite the stem cells' plasticity and adaptation to chronic hypoxia, the differentiated epithelium was significantly thinner with reduced barrier integrity. Stem cell lineage commitment shifted to a more secretory epithelial phenotype. Motile cilia abundance, length, beat frequency and coordination were significantly negatively modulated. Chronic hypoxia reduces the activity of epithelial sodium and CFTR ion channels. CFTR modulator drug response was diminished. Our findings shed light on the molecular pathophysiology of hypoxia and its implications in CF. Targeting hypoxia can be a strategy to augment mucosal function and may provide a means to enhance the efficacy of CFTR modulators.
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Affiliation(s)
- Sharon L Wong
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
- Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), University of New South Wales, Sydney, NSW 2052, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
| | - Egi Kardia
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
- Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), University of New South Wales, Sydney, NSW 2052, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
| | - Abhishek Vijayan
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
- Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), University of New South Wales, Sydney, NSW 2052, Australia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Bala Umashankar
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
- Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), University of New South Wales, Sydney, NSW 2052, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
| | - Elvis Pandzic
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ling Zhong
- Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, NSW 2052, Australia
| | - Adam Jaffe
- Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), University of New South Wales, Sydney, NSW 2052, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
- Department of Respiratory Medicine, Sydney Children's Hospital, Sydney, NSW 2052, Australia
| | - Shafagh A Waters
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
- Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), University of New South Wales, Sydney, NSW 2052, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
- Department of Respiratory Medicine, Sydney Children's Hospital, Sydney, NSW 2052, Australia
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Zhou W, Yu T, Hua Y, Hou Y, Ding Y, Nie H. Effects of Hypoxia on Respiratory Diseases: Perspective View of Epithelial Ion Transport. Am J Physiol Lung Cell Mol Physiol 2022; 323:L240-L250. [PMID: 35819839 DOI: 10.1152/ajplung.00065.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The balance of gas exchange and lung ventilation is essential for the maintenance of body homeostasis. There are many ion channels and transporters in respiratory epithelial cells, including epithelial sodium channel, Na,K-ATPase, cystic fibrosis transmembrane conductance regulator, and some transporters. These ion channels/transporters maintain the capacity of liquid layer on the surface of respiratory epithelial cells, and provide an immune barrier for the respiratory system to clear off foreign pathogens. However, in some harmful external environment and/or pathological conditions, the respiratory epithelium is prone to hypoxia, which would destroy the ion transport function of the epithelium and unbalance the homeostasis of internal environment, triggering a series of pathological reactions. Many respiratory diseases associated with hypoxia manifest an increased expression of hypoxia-inducible factor-1, which mediates the integrity of the epithelial barrier and affects epithelial ion transport function. It is important to study the relationship between hypoxia and ion transport function, whereas the mechanism of hypoxia-induced ion transport dysfunction in respiratory diseases is not clear. This review focuses on the relationship of hypoxia and respiratory diseases, as well as dysfunction of ion transport and tight junctions in respiratory epithelial cells under hypoxia.
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Affiliation(s)
- Wei Zhou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Tong Yu
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yu Hua
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yapeng Hou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yan Ding
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
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Jiang Y, Xia M, Xu J, Huang Q, Dai Z, Zhang X. Dexmedetomidine alleviates pulmonary edema through the epithelial sodium channel (ENaC) via the PI3K/Akt/Nedd4-2 pathway in LPS-induced acute lung injury. Immunol Res 2021; 69:162-175. [PMID: 33641076 PMCID: PMC8106593 DOI: 10.1007/s12026-021-09176-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/10/2021] [Indexed: 01/11/2023]
Abstract
Dexmedetomidine (Dex), a highly selective α2-adrenergic receptor (α2AR) agonist, has an anti-inflammatory property and can alleviate pulmonary edema in lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the mechanism is still unclear. In this study, we attempted to investigate the effect of Dex on alveolar epithelial sodium channel (ENaC) in the modulation of alveolar fluid clearance (AFC) and the underlying mechanism. Lipopolysaccharide (LPS) was used to induce acute lung injury (ALI) in rats and alveolar epithelial cell injury in A549 cells. In vivo, Dex markedly reduced pulmonary edema induced by LPS through promoting AFC, prevented LPS-induced downregulation of α-, β-, and γ-ENaC expression, attenuated inflammatory cell infiltration in lung tissue, reduced the concentrations of TNF-α, IL-1β, and IL-6, and increased concentrations of IL-10 in bronchoalveolar lavage fluid (BALF). In A549 cells stimulated with LPS, Dex attenuated LPS-mediated cell injury and the downregulation of α-, β-, and γ-ENaC expression. However, all of these effects were blocked by the PI3K inhibitor LY294002, suggesting that the protective role of Dex is PI3K-dependent. Additionally, Dex increased the expression of phosphorylated Akt and reduced the expression of Nedd4-2, while LY294002 reversed the effect of Dex in vivo and in vitro. Furthermore, insulin-like growth factor (IGF)-1, a PI3K agonists, promoted the expression of phosphorylated Akt and reduced the expression of Nedd4-2 in LPS-stimulated A549 cells, indicating that Dex worked through PI3K, and Akt and Nedd4-2 are downstream of PI3K. In conclusion, Dex alleviates pulmonary edema by suppressing inflammatory response in LPS-induced ALI, and the mechanism is partly related to the upregulation of ENaC expression via the PI3K/Akt/Nedd4-2 signaling pathway.
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Affiliation(s)
- Yuanxu Jiang
- Department of Anesthesiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The Fist Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China
- Shenzhen Anesthesiology Engineering Center, Shenzhen, 518020, China
| | - Mingzhu Xia
- Hubei Community Health Service Center, Luohu Hospital Group, Luohu People's Hospital, Shenzhen, 518020, China
| | - Jing Xu
- Department of Pathology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The Fist Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China
| | - Qiang Huang
- Department of Anesthesiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The Fist Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China
- Shenzhen Anesthesiology Engineering Center, Shenzhen, 518020, China
| | - Zhongliang Dai
- Department of Anesthesiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The Fist Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China.
- Shenzhen Anesthesiology Engineering Center, Shenzhen, 518020, China.
| | - Xueping Zhang
- Department of Anesthesiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The Fist Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China.
- Shenzhen Anesthesiology Engineering Center, Shenzhen, 518020, China.
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Kryvenko V, Vadász I. Molecular mechanisms of Na,K-ATPase dysregulation driving alveolar epithelial barrier failure in severe COVID-19. Am J Physiol Lung Cell Mol Physiol 2021; 320:L1186-L1193. [PMID: 33689516 PMCID: PMC8238442 DOI: 10.1152/ajplung.00056.2021] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A significant number of patients with coronavirus disease 2019 (COVID-19) develop acute respiratory distress syndrome (ARDS) that is associated with a poor outcome. The molecular mechanisms driving failure of the alveolar barrier upon severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain incompletely understood. The Na,K-ATPase is an adhesion molecule and a plasma membrane transporter that is critically required for proper alveolar epithelial function by both promoting barrier integrity and resolution of excess alveolar fluid, thus enabling appropriate gas exchange. However, numerous SARS-CoV-2-mediated and COVID-19-related signals directly or indirectly impair the function of the Na,K-ATPase, thereby potentially contributing to disease progression. In this Perspective, we highlight some of the putative mechanisms of SARS-CoV-2-driven dysfunction of the Na,K-ATPase, focusing on expression, maturation, and trafficking of the transporter. A therapeutic mean to selectively inhibit the maladaptive signals that impair the Na,K-ATPase upon SARS-CoV-2 infection might be effective in reestablishing the alveolar epithelial barrier and promoting alveolar fluid clearance and thus advantageous in patients with COVID-19-associated ARDS.
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Affiliation(s)
- Vitalii Kryvenko
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany
| | - István Vadász
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany
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9
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López-Hernández T, Haucke V, Maritzen T. Endocytosis in the adaptation to cellular stress. Cell Stress 2020; 4:230-247. [PMID: 33024932 PMCID: PMC7520666 DOI: 10.15698/cst2020.10.232] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/24/2020] [Accepted: 07/29/2020] [Indexed: 12/11/2022] Open
Abstract
Cellular life is challenged by a multitude of stress conditions, triggered for example by alterations in osmolarity, oxygen or nutrient supply. Hence, cells have developed sophisticated stress responses to cope with these challenges. Some of these stress programs such as the heat shock response are understood in great detail, while other aspects remain largely elusive including potential stress-dependent adaptations of the plasma membrane proteome. The plasma membrane is not only the first point of encounter for many types of environmental stress, but given the diversity of receptor proteins and their associated molecules also represents the site at which many cellular signal cascades originate. Since these signaling pathways affect virtually all aspects of cellular life, changes in the plasma membrane proteome appear ideally suited to contribute to the cellular adaptation to stress. The most rapid means to alter the cell surface proteome in response to stress is by alterations in endocytosis. Changes in the overall endocytic flux or in the endocytic regulation of select proteins conceivably can help to counteract adverse environmental conditions. In this review we summarize recent data regarding stress-induced changes in endocytosis and discuss how these changes might contribute to the cellular adaptation to stress in different systems. Future studies will be needed to uncover the underlying mechanisms in detail and to arrive at a coherent picture.
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Affiliation(s)
- Tania López-Hernández
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
- Freie Universität Berlin, Faculty of Biology, Chemistry, Pharmacy, 14195 Berlin, Germany
| | - Tanja Maritzen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
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10
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Del Vecchio L, Locatelli F. Hypoxia response and acute lung and kidney injury: possible implications for therapy of COVID-19. Clin Kidney J 2020; 13:494-499. [PMID: 32905208 PMCID: PMC7467604 DOI: 10.1093/ckj/sfaa149] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/09/2020] [Indexed: 12/11/2022] Open
Abstract
Coronavirus disease 2019 (COVID-19) is a pandemic of unprecedented severity affecting millions of people around the world and causing several hundred thousands of deaths. The presentation of the disease ranges from asymptomatic manifestations through to acute respiratory distress syndrome with the necessity of mechanical ventilation. Cytokine storm and maladaptive responses to the viral spread in the body could be responsible for the severity of disease. Many patients develop acute kidney injury (AKI) during the course of their disease, especially in more severe cases. Many factors could cause kidney damage during infection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. It is still unclear whether direct viral damage or the overexpression of cytokines and inflammatory factors are preeminent. According to autoptic studies, in most of the cases, AKI is due proximal tubular damage. However, cases of collapsing focal segmental glomerulosclerosis were reported as well in the absence of signs of direct viral infection of the kidney. Considering that severe hypoxia is a hallmark of severe SARS-CoV-2 infection, the involvement of the hypoxia-inducible factor (HIF) system is very likely, possibly influencing the inflammatory response and outcome in both the lungs and kidneys. Several bodies of evidence have shown a possible role of the HIF pathway during AKI in various kidney disease models. Similar observations were made in the setting of acute lung injury. In both organs, HIF activation by means of inhibition of the prolyl-hydroxylases domain (PHD) could be protective. Considering these promising experimental data, we hypothesize that PHD inhibitors could be considered as a possible new therapy against severe SARS-CoV-2 infection.
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Affiliation(s)
| | - Francesco Locatelli
- Past Director, Department of Nephrology and Dialysis, Alessandro Manzoni Hospital, ASST Lecco, Lecco, Italy
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11
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Uchiyama M, Nakao A, Kurita Y, Fukushi I, Takeda K, Numata T, Tran HN, Sawamura S, Ebert M, Kurokawa T, Sakaguchi R, Stokes AJ, Takahashi N, Okada Y, Mori Y. O 2-Dependent Protein Internalization Underlies Astrocytic Sensing of Acute Hypoxia by Restricting Multimodal TRPA1 Channel Responses. Curr Biol 2020; 30:3378-3396.e7. [PMID: 32679097 DOI: 10.1016/j.cub.2020.06.047] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 04/14/2020] [Accepted: 06/12/2020] [Indexed: 01/18/2023]
Abstract
Hypoxia sensors are essential for regulating local oxygen (O2) homeostasis within the body. This is especially pertinent within the CNS, which is particularly vulnerable to O2 deprivation due to high energetic demand. Here, we reveal hypoxia-monitoring function exerted by astrocytes through an O2-regulated protein trafficking mechanism within the CNS. Strikingly, cultured mouse astrocytes isolated from the parafacial respiratory group (pFRG) and retrotrapezoid nucleus (RTN) region are capable of rapidly responding to moderate hypoxia via the sensor cation channel transient receptor potential (TRP) A1 but, unlike multimodal sensory neurons, are inert to hyperoxia and other TRPA1 activators (carbon dioxide, electrophiles, and oxidants) in normoxia. Mechanistically, O2 suppresses TRPA1 channel activity by protein internalization via O2-dependent proline hydroxylation and subsequent ubiquitination by an E3 ubiquitin ligase, NEDD4-1 (neural precursor cell-expressed developmentally down-regulated protein 4). Hypoxia inhibits this process and instantly accumulates TRPA1 proteins at the plasma membrane, inducing TRPA1-mediated Ca2+ influx that triggers ATP release from pFRG/RTN astrocytes, potentiating respiratory center activity. Furthermore, astrocyte-specific Trpa1 disruption in a mouse brainstem-spinal cord preparation impedes the amplitude augmentation of the central autonomic respiratory output during hypoxia. Thus, reversible coupling of the TRPA1 channels with O2-dependent protein translocation allows astrocytes to act as acute hypoxia sensors in the medullary respiratory center.
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Affiliation(s)
- Makoto Uchiyama
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Akito Nakao
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Yuki Kurita
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Isato Fukushi
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo 208-0011, Japan; Faculty of Health Sciences, Uekusa Gakuen University, Chiba 264-0007, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo 208-0011, Japan; Faculty of Rehabilitation, School of Healthcare, Fujita Health University, 1-98, Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
| | - Tomohiro Numata
- Department of Physiology, School of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Ha Nam Tran
- Department of Technology and Ecology, Graduate School of Global Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Seishiro Sawamura
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Maximilian Ebert
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Tatsuki Kurokawa
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Reiko Sakaguchi
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan; World Premier International Research Initiative Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Alexander J Stokes
- Chaminade University, Honolulu, HI 96816, USA; Laboratory of Experimental Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96813, USA
| | - Nobuaki Takahashi
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo 208-0011, Japan
| | - Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
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12
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An outlined review for the role of Nedd4-1 and Nedd4-2 in lung disorders. Biomed Pharmacother 2020; 125:109983. [PMID: 32092816 DOI: 10.1016/j.biopha.2020.109983] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 12/16/2022] Open
Abstract
Neural precursor cell expressed, developmentally down-regulated 4, E3 ubiquitin protein ligase (Nedd4-1 and Nedd4-2) is a member of the HECT E3 ubiquitin ligase family. It has been shown to mediate numerous pathophysiological processes, including the regulation of synaptic plasticity and Wnt-associated signaling, via promoting the ubiquitination of its substrates, such as cyclic adenosine monophosphate (cAMP)-response element binding protein regulated transcription coactivator 3 (CRTC3), alpha-amino-3-hydroxy-5-methyl-4-isoxazo-lepropionic acid receptor (AMPAR), and Dishevelled2 (Dvl2). In the respiratory system, both Nedd4-1 and Nedd4-2 are expressed in epithelial cells and functionally associated with lung cancer development and alveolar fluid regulation. Nedd4-1 mediates lung cancer migration, metastasis, or drug resistance mainly through inducing phosphate and tension homology deleted on chromsome ten (PTEN) degradation or promoting cathepsin B secretion. Unlike Nedd4-1, Nedd4-2 displays more complex effects in lung cancers. On one hand it suppresses lung cancer cell migration and metastasis, and on the other hand it has been shown to promote lung cancer survival via inducing general control nonrepressed 2 (GCN2) degradation. Another important function of Nedd4-2 is to regulate the activity of epithelial sodium channel (ENaC), a membrane channel which mediates the clearance of fluid from the alveolar space at birth or during pulmonary edema. Here, we make an outlined review for the expression and function of Nedd4-1 and Nedd4-2 in the respiratory system in hope of getting an in-depth insight into their roles in lung disorders.
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13
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Magnani ND, Dada LA, Sznajder JI. Ubiquitin-proteasome signaling in lung injury. Transl Res 2018; 198:29-39. [PMID: 29752900 PMCID: PMC6986356 DOI: 10.1016/j.trsl.2018.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/15/2018] [Accepted: 04/16/2018] [Indexed: 12/21/2022]
Abstract
Cell homeostasis requires precise coordination of cellular proteins function. Ubiquitination is a post-translational modification that modulates protein half-life and function and is tightly regulated by ubiquitin E3 ligases and deubiquitinating enzymes. Lung injury can progress to acute respiratory distress syndrome that is characterized by an inflammatory response and disruption of the alveolocapillary barrier resulting in alveolar edema accumulation and hypoxemia. Ubiquitination plays an important role in the pathobiology of acute lung injury as it regulates the proteins modulating the alveolocapillary barrier and the inflammatory response. Better understanding of the signaling pathways regulated by ubiquitination may lead to novel therapeutic approaches by targeting specific elements of the ubiquitination pathways.
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Affiliation(s)
- Natalia D Magnani
- Pulmonary and Critical Care Division, Northwestern Feinberg School of Medicine, Chicago, Illinois
| | - Laura A Dada
- Pulmonary and Critical Care Division, Northwestern Feinberg School of Medicine, Chicago, Illinois
| | - Jacob I Sznajder
- Pulmonary and Critical Care Division, Northwestern Feinberg School of Medicine, Chicago, Illinois.
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14
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Winquist RJ, Cohen CJ. Integration of biological/pathophysiological contexts to help clarify genotype-phenotype mismatches in monogenetic diseases. Childhood epilepsies associated with SCN2A as a case study. Biochem Pharmacol 2018; 151:252-262. [DOI: 10.1016/j.bcp.2018.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/02/2018] [Indexed: 12/30/2022]
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15
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Zhuo XJ, Hao Y, Cao F, Yan SF, Li H, Wang Q, Cheng BH, Ying BY, Smith FG, Jin SW. Protectin DX increases alveolar fluid clearance in rats with lipopolysaccharide-induced acute lung injury. Exp Mol Med 2018; 50:1-13. [PMID: 29700291 PMCID: PMC5938057 DOI: 10.1038/s12276-018-0075-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 01/18/2018] [Accepted: 01/25/2018] [Indexed: 12/31/2022] Open
Abstract
Acute respiratory distress syndrome is a life-threatening critical syndrome resulting largely from the accumulation of and the inability to clear pulmonary edema. Protectin DX, an endogenously produced lipid mediator, is believed to exert anti-inflammatory and pro-resolution effects. Protectin DX (5 µg/kg) was injected i.v. 8 h after LPS (14 mg/kg) administration, and alveolar fluid clearance was measured in live rats (n = 8). In primary rat ATII epithelial cells, protectin DX (3.605 × 10−3 mg/l) was added to the culture medium with LPS for 6 h. Protectin DX improved alveolar fluid clearance (9.65 ± 1.60 vs. 15.85 ± 1.49, p < 0.0001) and decreased pulmonary edema and lung injury in LPS-induced lung injury in rats. Protectin DX markedly regulated alveolar fluid clearance by upregulating sodium channel and Na, K-ATPase protein expression levels in vivo and in vitro. Protectin DX also increased the activity of Na, K-ATPase and upregulated P-Akt via inhibiting Nedd4–2 in vivo. In addition, protectin DX enhanced the subcellular distribution of sodium channels and Na, K-ATPase, which were specifically localized to the apical and basal membranes of primary rat ATII cells. Furthermore, BOC-2, Rp-cAMP, and LY294002 blocked the increased alveolar fluid clearance in response to protectin DX. Protectin DX stimulates alveolar fluid clearance through a mechanism partly dependent on alveolar epithelial sodium channel and Na, K-ATPase activation via the ALX/PI3K/Nedd4–2 signaling pathway. Treatment that involves boosting levels of a signaling molecule could help reduce fluid on the lungs in acute respiratory distress syndrome (ARDS). This condition usually affects critically ill patients with illnesses such as pneumonia or sepsis, and leads to severe inflammation and flooding of the lungs with fluid. This prevents microscopic air sacs called aveoli from processing oxygen and carbon dioxide effectively. At present there is no effective management for the condition. Now, Sheng-Wei Jin at Wenzhou Medical University, China, and co-workers have shown that boosting levels of a signaling molecule called protectin DX can help with aveolar fluid clearance in rats. They found that protectin DX activates sodium channels within the aveoli, helping clear fluid, and also acts as an anti-inflammatory and pro-resolving mediator to protect lung tissues from further injury.
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Affiliation(s)
- Xiao-Jun Zhuo
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China
| | - Yu Hao
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China
| | - Fei Cao
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China
| | - Song-Fan Yan
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China
| | - Hui Li
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China
| | - Qian Wang
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China
| | - Bi-Huan Cheng
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China
| | - Bin-Yu Ying
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China
| | - Fang Gao Smith
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China.,Institute of Inflammation and Aging, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.,Academic Department of Anesthesia, Critical Care, Pain and Resuscitation, Birmingham Heartlands Hospital, Heart of England NHS Foundation Trust, Birmingham, B9 5SS, UK
| | - Sheng-Wei Jin
- Department of Anesthesia and Critical Care, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, 325027, Zhejiang, China.
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16
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Intermittent Hypoxia Increases the Severity of Bleomycin-Induced Lung Injury in Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:1240192. [PMID: 29725493 PMCID: PMC5872634 DOI: 10.1155/2018/1240192] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 01/03/2018] [Accepted: 01/10/2018] [Indexed: 01/02/2023]
Abstract
Background Severe obstructive sleep apnea (OSA) with chronic intermittent hypoxia (IH) is common in idiopathic pulmonary fibrosis (IPF). Here, we evaluated the impact of IH on bleomycin- (BLM-) induced pulmonary fibrosis in mice. Methods C57BL/6J mice received intratracheal BLM or saline and were exposed to IH (40 cycles/hour; FiO2 nadir: 6%; 8 hours/day) or intermittent air (IA). In the four experimental groups, we evaluated (i) survival; (ii) alveolar inflammation, pulmonary edema, lung oxidative stress, and antioxidant enzymes; (iii) lung cell apoptosis; and (iv) pulmonary fibrosis. Results Survival at day 21 was lower in the BLM-IH group (p < 0.05). Pulmonary fibrosis was more severe at day 21 in BLM-IH mice, as assessed by lung collagen content (p = 0.02) and histology. At day 4, BLM-IH mice developed a more severe neutrophilic alveolitis, (p < 0.001). Lung oxidative stress was observed, and superoxide dismutase and glutathione peroxidase expression was decreased in BLM-IH mice (p < 0.05 versus BLM-IA group). At day 8, pulmonary edema was observed and lung cell apoptosis was increased in the BLM-IH group. Conclusion These results show that exposure to chronic IH increases mortality, lung inflammation, and lung fibrosis in BLM-treated mice. This study raises the question of the worsening impact of severe OSA in IPF patients.
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17
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Hamacher J, Hadizamani Y, Borgmann M, Mohaupt M, Männel DN, Moehrlen U, Lucas R, Stammberger U. Cytokine-Ion Channel Interactions in Pulmonary Inflammation. Front Immunol 2018; 8:1644. [PMID: 29354115 PMCID: PMC5758508 DOI: 10.3389/fimmu.2017.01644] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/10/2017] [Indexed: 12/12/2022] Open
Abstract
The lungs conceptually represent a sponge that is interposed in series in the bodies’ systemic circulation to take up oxygen and eliminate carbon dioxide. As such, it matches the huge surface areas of the alveolar epithelium to the pulmonary blood capillaries. The lung’s constant exposure to the exterior necessitates a competent immune system, as evidenced by the association of clinical immunodeficiencies with pulmonary infections. From the in utero to the postnatal and adult situation, there is an inherent vital need to manage alveolar fluid reabsorption, be it postnatally, or in case of hydrostatic or permeability edema. Whereas a wealth of literature exists on the physiological basis of fluid and solute reabsorption by ion channels and water pores, only sparse knowledge is available so far on pathological situations, such as in microbial infection, acute lung injury or acute respiratory distress syndrome, and in the pulmonary reimplantation response in transplanted lungs. The aim of this review is to discuss alveolar liquid clearance in a selection of lung injury models, thereby especially focusing on cytokines and mediators that modulate ion channels. Inflammation is characterized by complex and probably time-dependent co-signaling, interactions between the involved cell types, as well as by cell demise and barrier dysfunction, which may not uniquely determine a clinical picture. This review, therefore, aims to give integrative thoughts and wants to foster the unraveling of unmet needs in future research.
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Affiliation(s)
- Jürg Hamacher
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Internal Medicine V - Pneumology, Allergology, Respiratory and Environmental Medicine, Faculty of Medicine, Saarland University, Saarbrücken, Germany.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Yalda Hadizamani
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Michèle Borgmann
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Markus Mohaupt
- Internal Medicine, Sonnenhofspital Bern, Bern, Switzerland
| | | | - Ueli Moehrlen
- Paediatric Visceral Surgery, Universitäts-Kinderspital Zürich, Zürich, Switzerland
| | - Rudolf Lucas
- Department of Pharmacology and Toxicology, Vascular Biology Center, Medical College of Georgia, Augusta, GA, United States
| | - Uz Stammberger
- Lungen- und Atmungsstiftung Bern, Bern, Switzerland.,Novartis Institutes for Biomedical Research, Translational Clinical Oncology, Novartis Pharma AG, Basel, Switzerland
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18
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HIF and HOIL-1L-mediated PKCζ degradation stabilizes plasma membrane Na,K-ATPase to protect against hypoxia-induced lung injury. Proc Natl Acad Sci U S A 2017; 114:E10178-E10186. [PMID: 29109255 DOI: 10.1073/pnas.1713563114] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Organisms have evolved adaptive mechanisms in response to stress for cellular survival. During acute hypoxic stress, cells down-regulate energy-consuming enzymes such as Na,K-ATPase. Within minutes of alveolar epithelial cell (AEC) exposure to hypoxia, protein kinase C zeta (PKCζ) phosphorylates the α1-Na,K-ATPase subunit and triggers it for endocytosis, independently of the hypoxia-inducible factor (HIF). However, the Na,K-ATPase activity is essential for cell homeostasis. HIF induces the heme-oxidized IRP2 ubiquitin ligase 1L (HOIL-1L), which leads to PKCζ degradation. Here we report a mechanism of prosurvival adaptation of AECs to prolonged hypoxia where PKCζ degradation allows plasma membrane Na,K-ATPase stabilization at ∼50% of normoxic levels, preventing its excessive down-regulation and cell death. Mice lacking HOIL-1L in lung epithelial cells (CreSPC/HOIL-1Lfl/fl ) were sensitized to hypoxia because they express higher levels of PKCζ and, consequently, lower plasma membrane Na,K-ATPase levels, which increased cell death and worsened lung injury. In AECs, expression of an α1-Na,K-ATPase construct bearing an S18A (α1-S18A) mutation, which precludes PKCζ phosphorylation, stabilized the Na,K-ATPase at the plasma membrane and prevented hypoxia-induced cell death even in the absence of HOIL-1L. Adenoviral overexpression of the α1-S18A mutant Na,K-ATPase in vivo rescued the enhanced sensitivity of CreSPC/HOIL-1Lfl/fl mice to hypoxic lung injury. These data suggest that stabilization of Na,K-ATPase during severe hypoxia is a HIF-dependent process involving PKCζ degradation. Accordingly, we provide evidence of an important adaptive mechanism to severe hypoxia, whereby halting the exaggerated down-regulation of plasma membrane Na,K-ATPase prevents cell death and lung injury.
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19
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Wheatley CM, Baker SE, Taylor BJ, Keller-Ross ML, Chase SC, Carlson AR, Wentz RJ, Snyder EM, Johnson BD. Influence of Inhaled Amiloride on Lung Fluid Clearance in Response to Normobaric Hypoxia in Healthy Individuals. High Alt Med Biol 2017; 18:343-354. [PMID: 28876128 DOI: 10.1089/ham.2017.0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Wheatley, Courtney M., Sarah E. Baker, Bryan J. Taylor, Manda L. Keller-Ross, Steven C. Chase, Alex R. Carlson, Robert J. Wentz, Eric M. Snyder, and Bruce D. Johnson. Influence of inhaled amiloride on lung fluid clearance in response to normobaric hypoxia in healthy individuals. High Alt Med Biol 18:343-354, 2017. AIM To investigate the role of epithelial sodium channels (ENaC) on lung fluid clearance in response to normobaric hypoxia, 20 healthy subjects were exposed to 15 hours of hypoxia (fraction of inspired oxygen [FiO2] = 12.5%) on two randomized occasions: (1) inhaled amiloride (A) (1.5 mg/5 mL saline); and (2) inhaled saline placebo (P). Changes in lung fluid were assessed through chest computed tomography (CT) for lung tissue volume (TV), and the diffusion capacity of the lungs for carbon monoxide (DLCO) and nitric oxide (DLNO) for pulmonary capillary blood volume (VC). Extravascular lung water (EVLW) was derived as TV-VC and changes in the CT attenuation distribution histograms were reviewed. RESULTS Normobaric hypoxia caused (1) a reduction in EVLW (change from baseline for A vs. P, -8.5% ± 3.8% vs. -7.9% ± 5.2%, p < 0.05), (2) an increase in VC (53.6% ± 28.9% vs. 53.9% ± 52.3%, p < 0.05), (3) a small increase in DLCO (9.6% ± 29.3% vs. 9.9% ± 23.9%, p > 0.05), and (4) CT attenuation distribution became more negative, leftward skewed, and kurtotic (p < 0.05). CONCLUSION Acute normobaric hypoxia caused a reduction in lung fluid that was unaffected by ENaC inhibition through inhaled amiloride. Although possible amiloride-sensitive ENaC may not be necessary to maintain lung fluid balance in response to hypoxia, it is more probable that normobaric hypoxia promotes lung fluid clearance rather than accumulation for the majority of healthy individuals. The observed reduction in interstitial lung fluid means alveolar fluid clearance may not have been challenged.
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Affiliation(s)
- Courtney M Wheatley
- 1 Department of Pharmaceutical Science, University of Arizona , Tucson, Arizona
| | - Sarah E Baker
- 1 Department of Pharmaceutical Science, University of Arizona , Tucson, Arizona
| | - Bryan J Taylor
- 2 Division of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
| | | | - Steven C Chase
- 2 Division of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
| | - Alex R Carlson
- 2 Division of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
| | - Robert J Wentz
- 2 Division of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
| | - Eric M Snyder
- 1 Department of Pharmaceutical Science, University of Arizona , Tucson, Arizona
| | - Bruce D Johnson
- 2 Division of Cardiovascular Diseases, Mayo Clinic , Rochester, Minnesota
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20
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Inhibitors of the proteasome stimulate the epithelial sodium channel (ENaC) through SGK1 and mimic the effect of aldosterone. Pflugers Arch 2017; 470:295-304. [DOI: 10.1007/s00424-017-2060-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/17/2017] [Accepted: 08/21/2017] [Indexed: 10/19/2022]
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21
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Lamothe SM, Song W, Guo J, Li W, Yang T, Baranchuk A, Graham CH, Zhang S. Hypoxia reduces mature hERG channels through calpain up‐regulation. FASEB J 2017; 31:5068-5077. [DOI: 10.1096/fj.201700255r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/17/2017] [Indexed: 01/07/2023]
Affiliation(s)
- Shawn M. Lamothe
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - WonJu Song
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Jun Guo
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Wentao Li
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Tonghua Yang
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Adrian Baranchuk
- Department of Medicine, Kingston General HospitalQueen’s UniversityKingstonOntarioCanada
| | - Charles H. Graham
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
| | - Shetuan Zhang
- Department of Biomedical and Molecular SciencesQueen’s UniversityKingstonOntarioCanada
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22
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Gwoździńska P, Buchbinder BA, Mayer K, Herold S, Morty RE, Seeger W, Vadász I. Hypercapnia Impairs ENaC Cell Surface Stability by Promoting Phosphorylation, Polyubiquitination and Endocytosis of β-ENaC in a Human Alveolar Epithelial Cell Line. Front Immunol 2017; 8:591. [PMID: 28588583 PMCID: PMC5440515 DOI: 10.3389/fimmu.2017.00591] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 05/04/2017] [Indexed: 01/11/2023] Open
Abstract
Acute lung injury is associated with formation of pulmonary edema leading to impaired gas exchange. Patients with acute respiratory distress syndrome (ARDS) require mechanical ventilation to improve oxygenation; however, the use of relatively low tidal volumes (to minimize further injury of the lung) often leads to further accumulation of carbon dioxide (hypercapnia). Hypercapnia has been shown to impair alveolar fluid clearance (AFC), thereby causing retention of pulmonary edema, and may lead to worse outcomes; however, the underlying molecular mechanisms remain incompletely understood. AFC is critically dependent on the epithelial sodium channel (ENaC), which drives the vectorial transport of Na+ across the alveolar epithelium. Thus, in the current study, we investigated the mechanisms by which hypercapnia effects ENaC cell surface stability in alveolar epithelial cells (AECs). Elevated CO2 levels led to polyubiquitination of β-ENaC and subsequent endocytosis of the α/β-ENaC complex in AECs, which were prevented by silencing the E3 ubiquitin ligase, Nedd4-2. Hypercapnia-induced ubiquitination and cell surface retrieval of ENaC were critically dependent on phosphorylation of the Thr615 residue of β-ENaC, which was mediated by the extracellular signal-regulated kinase (ERK)1/2. Furthermore, activation of ERK1/2 led to subsequent activation of AMP-activated protein kinase (AMPK) and c-Jun N-terminal kinase (JNK)1/2 that in turn phosphorylated Nedd4-2 at the Thr899 residue. Importantly, mutation of Thr899 to Ala markedly inhibited the CO2-induced polyubiquitination of β-ENaC and restored cell surface stability of the ENaC complex, highlighting the critical role of Nedd4-2 phosphorylation status in targeting ENaC. Collectively, our data suggest that elevated CO2 levels promote activation of the ERK/AMPK/JNK axis in a human AEC line, in which ERK1/2 phosphorylates β-ENaC whereas JNK mediates phosphorylation of Nedd4-2, thereby facilitating the channel-ligase interaction. The hypercapnia-induced ENaC dysfunction may contribute to impaired alveolar edema clearance and thus, interfering with these molecular mechanisms may improve alveolar fluid balance and lead to better outcomes in patients with ARDS.
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Affiliation(s)
- Paulina Gwoździńska
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Benno A Buchbinder
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Konstantin Mayer
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Susanne Herold
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
| | - Rory E Morty
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany.,Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Werner Seeger
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany.,Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - István Vadász
- Department of Internal Medicine, Justus Liebig University, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Giessen, Germany
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23
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Zhang JL, Zhuo XJ, Lin J, Luo LC, Ying WY, Xie X, Zhang HW, Yang JX, Li D, Gao Smith F, Jin SW. Maresin1 stimulates alveolar fluid clearance through the alveolar epithelial sodium channel Na,K-ATPase via the ALX/PI3K/Nedd4-2 pathway. J Transl Med 2017; 97:543-554. [PMID: 28218740 DOI: 10.1038/labinvest.2016.150] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 11/26/2016] [Accepted: 12/06/2016] [Indexed: 12/31/2022] Open
Abstract
Maresin1 (MaR1) is a new docosahexaenoic acid-derived pro-resolving agent that promotes the resolution of inflammation. In this study, we sought to investigate the effect and underlining mechanisms of MaR1 in modulating alveolar fluid clearance (AFC) on LPS-induced acute lung injury. MaR1 was injected intravenously or administered by instillation (200 ng/kg) 8 h after LPS (14 mg/kg) administration and AFC was measured in live rats. In primary rat alveolar type II epithelial cells, MaR1 (100 nM) was added to the culture medium with lipopolysaccharide for 6 h. MaR1 markedly stimulated AFC in LPS-induced lung injury, with the outcome of decreased pulmonary edema and lung injury. In addition, rat lung tissue protein was isolated after intervention, and we found MaR1 improved epithelial sodium channel (ENaC), Na,K-adenosine triphosphatase (ATPase) protein expression and Na,K-ATPase activity. MaR1 down-regulated Nedd4-2 protein expression though PI3k/Akt but not though PI3k/SGK1 pathway in vivo. In primary rat alveolar type II epithelial cells stimulated with LPS, MaR1-upregulated ENaC and Na,K-ATPase protein abundance in the plasma membrane. Finally, the lipoxin A4 Receptor inhibitor (BOC-2) and PI3K inhibitor (LY294002) not only blocked MaR1's effects on cAMP/cGMP, the expression of phosphorylated Akt and Nedd4-2, but also inhibited the effect of MaR1 on AFC in vivo. In conclusion, MaR1 stimulates AFC through a mechanism partly dependent on alveolar epithelial ENaC and Na,K-ATPase activation via the ALX/PI3K/Nedd4-2 signaling pathway. Our findings reveal a novel mechanism for pulmonary edema fluid reabsorption and MaR1 may provide a new therapy for the resolution of ALI/ARDS.
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Affiliation(s)
- Jun-Li Zhang
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Xiao-Jun Zhuo
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Jing Lin
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Ling-Chun Luo
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Wei-Yang Ying
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Xiang Xie
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Hua-Wei Zhang
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Jing-Xiang Yang
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Dan Li
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
| | - Fang Gao Smith
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China.,Academic Department of Anesthesia, Critical Care, Pain and Resuscitation, Birmingham Heartlands Hospital, Heart of England NHS Foundation Trust, Birmingham, UK
| | - Sheng-Wei Jin
- Department of Anesthesia and Critical Care, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, China
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24
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Trac PT, Thai TL, Linck V, Zou L, Greenlee M, Yue Q, Al-Khalili O, Alli AA, Eaton AF, Eaton DC. Alveolar nonselective channels are ASIC1a/α-ENaC channels and contribute to AFC. Am J Physiol Lung Cell Mol Physiol 2017; 312:L797-L811. [PMID: 28283476 DOI: 10.1152/ajplung.00379.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/01/2017] [Accepted: 03/02/2017] [Indexed: 12/13/2022] Open
Abstract
A thin fluid layer in alveoli is normal and results from a balance of fluid entry and fluid uptake by transepithelial salt and water reabsorption. Conventional wisdom suggests the reabsorption is via epithelial Na+ channels (ENaC), but if all Na+ reabsorption were via ENaC, then amiloride, an ENaC inhibitor, should block alveolar fluid clearance (AFC). However, amiloride blocks only half of AFC. The reason for failure to block is clear from single-channel measurements from alveolar epithelial cells: ENaC channels are observed, but another channel is present at the same frequency that is nonselective for Na+ over K+, has a larger conductance, and has shorter open and closed times. These two channel types are known as highly selective channels (HSC) and nonselective cation channels (NSC). HSC channels are made up of three ENaC subunits since knocking down any of the subunits reduces HSC number. NSC channels contain α-ENaC since knocking down α-ENaC reduces the number of NSC (knocking down β- or γ-ENaC has no effect on NSC, but the molecular composition of NSC channels remains unclear). We show that NSC channels consist of at least one α-ENaC and one or more acid-sensing ion channel 1a (ASIC1a) proteins. Knocking down either α-ENaC or ASIC1a reduces both NSC and HSC number, and no NSC channels are observable in single-channel patches on lung slices from ASIC1a knockout mice. AFC is reduced in knockout mice, and wet wt-to-dry wt ratio is increased, but the percentage increase in wet wt-to-dry wt ratio is larger than expected based on the reduction in AFC.
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Affiliation(s)
- Phi T Trac
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Tiffany L Thai
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Valerie Linck
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Li Zou
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Megan Greenlee
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Qiang Yue
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Otor Al-Khalili
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida
| | - Amity F Eaton
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
| | - Douglas C Eaton
- Department of Physiology and Center for Cell and Molecular Signaling, Emory University School of Medicine, Atlanta, Georgia; and
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25
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Solnatide Demonstrates Profound Therapeutic Activity in a Rat Model of Pulmonary Edema Induced by Acute Hypobaric Hypoxia and Exercise. Chest 2017; 151:658-667. [DOI: 10.1016/j.chest.2016.10.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/11/2016] [Accepted: 10/17/2016] [Indexed: 11/23/2022] Open
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26
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Willam A, Aufy M, Tzotzos S, Evanzin H, Chytracek S, Geppert S, Fischer B, Fischer H, Pietschmann H, Czikora I, Lucas R, Lemmens-Gruber R, Shabbir W. Restoration of Epithelial Sodium Channel Function by Synthetic Peptides in Pseudohypoaldosteronism Type 1B Mutants. Front Pharmacol 2017; 8:85. [PMID: 28286482 PMCID: PMC5323398 DOI: 10.3389/fphar.2017.00085] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/09/2017] [Indexed: 12/20/2022] Open
Abstract
The synthetically produced cyclic peptides solnatide (a.k.a. TIP or AP301) and its congener AP318, whose molecular structures mimic the lectin-like domain of human tumor necrosis factor (TNF), have been shown to activate the epithelial sodium channel (ENaC) in various cell- and animal-based studies. Loss-of-ENaC-function leads to a rare, life-threatening, salt-wasting syndrome, pseudohypoaldosteronism type 1B (PHA1B), which presents with failure to thrive, dehydration, low blood pressure, anorexia and vomiting; hyperkalemia, hyponatremia and metabolic acidosis suggest hypoaldosteronism, but plasma aldosterone and renin activity are high. The aim of the present study was to investigate whether the ENaC-activating effect of solnatide and AP318 could rescue loss-of-function phenotype of ENaC carrying mutations at conserved amino acid positions observed to cause PHA1B. The macroscopic Na+ current of all investigated mutants was decreased compared to wild type ENaC when measured in whole-cell patch clamp experiments, and a great variation in the membrane abundance of different mutant ENaCs was observed with Western blotting experiments. However, whatever mechanism leads to loss-of-function of the studied ENaC mutations, the synthetic peptides solnatide and AP318 could restore ENaC function up to or even higher than current levels of wild type ENaC. As therapy of PHA1B is only symptomatic so far, the peptides solnatide and AP318, which directly target ENaC, are promising candidates for the treatment of the channelopathy-caused disease PHA1B.
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Affiliation(s)
- Anita Willam
- Department of Pharmacology and Toxicology, University of Vienna Vienna, Austria
| | - Mohammed Aufy
- Department of Pharmacology and Toxicology, University of Vienna Vienna, Austria
| | | | - Heinrich Evanzin
- Department of Pharmacology and Toxicology, University of Vienna Vienna, Austria
| | - Sabine Chytracek
- Department of Pharmacology and Toxicology, University of Vienna Vienna, Austria
| | - Sabrina Geppert
- Department of Pharmacology and Toxicology, University of Vienna Vienna, Austria
| | | | | | | | - Istvan Czikora
- Vascular Biology Center, Medical College of Georgia, Augusta University Augusta, GA, USA
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Augusta University Augusta, GA, USA
| | - Rosa Lemmens-Gruber
- Department of Pharmacology and Toxicology, University of Vienna Vienna, Austria
| | - Waheed Shabbir
- Department of Pharmacology and Toxicology, University of ViennaVienna, Austria; APEPTICO GmbHVienna, Austria
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27
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Krause NC, Kutsche HS, Santangelo F, DeLeon ER, Dittrich NP, Olson KR, Althaus M. Hydrogen sulfide contributes to hypoxic inhibition of airway transepithelial sodium absorption. Am J Physiol Regul Integr Comp Physiol 2016; 311:R607-17. [DOI: 10.1152/ajpregu.00177.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/13/2016] [Indexed: 01/23/2023]
Abstract
In lung epithelial cells, hypoxia decreases the expression and activity of sodium-transporting molecules, thereby reducing the rate of transepithelial sodium absorption. The mechanisms underlying the sensing of hypoxia and subsequent coupling to sodium-transporting molecules remain unclear. Hydrogen sulfide (H2S) has recently been recognized as a cellular signaling molecule whose intracellular concentrations critically depend on oxygen levels. Therefore, it was questioned whether endogenously produced H2S contributes to hypoxic inhibition of sodium transport. In electrophysiological Ussing chamber experiments, hypoxia was established by decreasing oxygen concentrations in the chambers. Hypoxia concentration dependently and reversibly decreased amiloride-sensitive sodium absorption by cultured H441 monolayers and freshly dissected porcine tracheal epithelia due to inhibition of basolateral Na+/K+-ATPase. Exogenous application of H2S by the sulfur salt Na2S mimicked the effect of hypoxia and inhibited amiloride-sensitive sodium absorption by both tissues in an oxygen-dependent manner. Hypoxia increased intracellular concentrations of H2S and decreased the concentration of polysulfides. Pretreatment with the cystathionine-γ-lyase inhibitor d/l-propargylglycine (PAG) decreased hypoxic inhibition of sodium transport by H441 monolayers, whereas inhibition of cystathionine-β-synthase (with aminooxy-acetic acid; AOAA) or 3-mercaptopyruvate sulfurtransferase (with aspartate) had no effect. Inhibition of all of these H2S-generating enzymes with a combination of AOAA, PAG, and aspartate decreased the hypoxic inhibition of sodium transport by H441 cells and pig tracheae and decreased H2S production by tracheae. These data suggest that airway epithelial cells endogenously produce H2S during hypoxia, and this contributes to hypoxic inhibition of transepithelial sodium absorption.
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Affiliation(s)
- Nicole C. Krause
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany; and
| | - Hanna S. Kutsche
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany; and
| | - Fabrizio Santangelo
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany; and
| | - Eric R. DeLeon
- Department of Physiology, Indiana University School of Medicine-South Bend, South Bend, Indiana
| | - Nikolaus P. Dittrich
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany; and
| | - Kenneth R. Olson
- Department of Physiology, Indiana University School of Medicine-South Bend, South Bend, Indiana
| | - Mike Althaus
- Institute for Animal Physiology, Justus-Liebig-University, Giessen, Germany; and
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28
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Boscardin E, Alijevic O, Hummler E, Frateschi S, Kellenberger S. The function and regulation of acid-sensing ion channels (ASICs) and the epithelial Na(+) channel (ENaC): IUPHAR Review 19. Br J Pharmacol 2016; 173:2671-701. [PMID: 27278329 DOI: 10.1111/bph.13533] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/19/2016] [Accepted: 06/02/2016] [Indexed: 12/30/2022] Open
Abstract
Acid-sensing ion channels (ASICs) and the epithelial Na(+) channel (ENaC) are both members of the ENaC/degenerin family of amiloride-sensitive Na(+) channels. ASICs act as proton sensors in the nervous system where they contribute, besides other roles, to fear behaviour, learning and pain sensation. ENaC mediates Na(+) reabsorption across epithelia of the distal kidney and colon and of the airways. ENaC is a clinically used drug target in the context of hypertension and cystic fibrosis, while ASIC is an interesting potential target. Following a brief introduction, here we will review selected aspects of ASIC and ENaC function. We discuss the origin and nature of pH changes in the brain and the involvement of ASICs in synaptic signalling. We expose how in the peripheral nervous system, ASICs cover together with other ion channels a wide pH range as proton sensors. We introduce the mechanisms of aldosterone-dependent ENaC regulation and the evidence for an aldosterone-independent control of ENaC activity, such as regulation by dietary K(+) . We then provide an overview of the regulation of ENaC by proteases, a topic of increasing interest over the past few years. In spite of the profound differences in the physiological and pathological roles of ASICs and ENaC, these channels share many basic functional and structural properties. It is likely that further research will identify physiological contexts in which ASICs and ENaC have similar or overlapping roles.
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Affiliation(s)
- Emilie Boscardin
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Omar Alijevic
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Edith Hummler
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
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29
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Favier FB, Britto FA, Freyssenet DG, Bigard XA, Benoit H. HIF-1-driven skeletal muscle adaptations to chronic hypoxia: molecular insights into muscle physiology. Cell Mol Life Sci 2015; 72:4681-96. [PMID: 26298291 PMCID: PMC11113128 DOI: 10.1007/s00018-015-2025-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 08/14/2015] [Accepted: 08/18/2015] [Indexed: 12/12/2022]
Abstract
Skeletal muscle is a metabolically active tissue and the major body protein reservoir. Drop in ambient oxygen pressure likely results in a decrease in muscle cells oxygenation, reactive oxygen species (ROS) overproduction and stabilization of the oxygen-sensitive hypoxia-inducible factor (HIF)-1α. However, skeletal muscle seems to be quite resistant to hypoxia compared to other organs, probably because it is accustomed to hypoxic episodes during physical exercise. Few studies have observed HIF-1α accumulation in skeletal muscle during ambient hypoxia probably because of its transient stabilization. Nevertheless, skeletal muscle presents adaptations to hypoxia that fit with HIF-1 activation, although the exact contribution of HIF-2, I kappa B kinase and activating transcription factors, all potentially activated by hypoxia, needs to be determined. Metabolic alterations result in the inhibition of fatty acid oxidation, while activation of anaerobic glycolysis is less evident. Hypoxia causes mitochondrial remodeling and enhanced mitophagy that ultimately lead to a decrease in ROS production, and this acclimatization in turn contributes to HIF-1α destabilization. Likewise, hypoxia has structural consequences with muscle fiber atrophy due to mTOR-dependent inhibition of protein synthesis and transient activation of proteolysis. The decrease in muscle fiber area improves oxygen diffusion into muscle cells, while inhibition of protein synthesis, an ATP-consuming process, and reduction in muscle mass decreases energy demand. Amino acids released from muscle cells may also have protective and metabolic effects. Collectively, these results demonstrate that skeletal muscle copes with the energetic challenge imposed by O2 rarefaction via metabolic optimization.
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Affiliation(s)
- F B Favier
- INRA, UMR 866 Dynamique Musculaire et Métabolisme, 34060, Montpellier, France.
- Université de Montpellier, 34090, Montpellier, France.
| | - F A Britto
- INRA, UMR 866 Dynamique Musculaire et Métabolisme, 34060, Montpellier, France
- Université de Montpellier, 34090, Montpellier, France
| | - D G Freyssenet
- Laboratoire de Physiologie de l'Exercice EA 4338, Université de Lyon, Université Jean Monnet, 42000, Saint Etienne, France
| | - X A Bigard
- Agence Française de Lutte contre le Dopage, 75007, Paris, France
| | - H Benoit
- INSERM, U1042 Hypoxie Physio-Pathologie, 38000, Grenoble, France
- Université Joseph Fourier, 38000, Grenoble, France
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30
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Abstract
PURPOSE OF REVIEW NEDD4-2 is an ubiquitin-protein ligase that was originally identified as an interactor of the epithelial Na+ channel (ENaC); this interaction is defective in Liddle's syndrome, causing elevated ENaC activity and salt-sensitive hypertension. In this review we aim to highlight progress achieved in recent years demonstrating that NEDD4-2 is involved in the control of Na+ transporters that are different from ENaC, but which also play a role in salt-sensitive hypertension. RECENT FINDINGS It has been shown that NEDD4-2 interacts with ubiquitylates and negatively regulates the thiazide-sensitive NCC (Na+,Cl- -cotransporter), both in vitro and in vivo in inducible, nephron-specific Nedd4-2 knockout mice. Moreover, evidence has been provided that NEDD4-2 is also involved in the regulation of human NHE3 (Na+,H+-exchanger 3) and NKCC2 (Na+,K+,2Cl- -cotransporter 2). SUMMARY The emerging role of NEDD4-2 in the regulation of different Na+ transporters along the nephron and the identification of human polymorphisms in the NEDD4-2 gene (Nedd4L) related to salt-sensitive hypertension makes this ubiquitin-protein ligase an interesting target for the development of antihypertensive drugs.
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31
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Han S, Mallampalli RK. The acute respiratory distress syndrome: from mechanism to translation. THE JOURNAL OF IMMUNOLOGY 2015; 194:855-60. [PMID: 25596299 DOI: 10.4049/jimmunol.1402513] [Citation(s) in RCA: 265] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The acute respiratory distress syndrome (ARDS) is a form of severe hypoxemic respiratory failure that is characterized by inflammatory injury to the alveolar capillary barrier, with extravasation of protein-rich edema fluid into the airspace. Although many modalities to treat ARDS have been investigated over the past several decades, supportive therapies remain the mainstay of treatment. In this article, we briefly review the definition, epidemiology, and pathophysiology of ARDS and present emerging aspects of ARDS pathophysiology that encompass modulators of the innate immune response, damage signals, and aberrant proteolysis that may serve as a foundation for future therapeutic targets.
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Affiliation(s)
- SeungHye Han
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213
| | - Rama K Mallampalli
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213; Department of Cell Biology and Physiology, University of Pittsburgh, Pittsburgh, PA 15213; and Medical Specialty Service Line, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15240
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32
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Liu H, Wang Z, Yu S, Xu J. Proteasomal degradation of O-GlcNAc transferase elevates hypoxia-induced vascular endothelial inflammatory response†. Cardiovasc Res 2014; 103:131-9. [PMID: 24788415 DOI: 10.1093/cvr/cvu116] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
AIMS Hypoxia induces vascular inflammation by a mechanism not fully understood. Emerging evidence implicates O-GlcNAc transferase (OGT) in inflammation. This study explored the role of OGT in hypoxia-induced vascular endothelial inflammatory response. METHODS AND RESULTS Hypoxia was either induced (1% O2 chamber) or mimicked by exposure to hypoxia-mimetic agents in cultured endothelial cells. Hypoxia increased hypoxia-inducible factor (HIF-1α) and inflammatory response (gene and protein expression of interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1, and E-selectin) but, surprisingly, reduced OGT protein (not mRNA) levels. Hypoxia-mimetic CoCl2 failed to reduce OGT when proteasome inhibitors were present, suggesting proteasome involvement. Indeed, CoCl2 enhanced 26S proteasome functionality evidenced by diminished reporter (Ub(G76V)-GFP) proteins in proteasome reporter cells, likely due to increased chymotrypsin-like activities. Mechanistically, β-TrCP1 mediated OGT degradation, since siRNA ablation of this E3 ubiquitin ligase stabilized OGT. Administration of the oxidative stress inhibitors reversed both proteasome activation and OGT degradation. Furthermore, up-regulation of OGT by stabilization, overexpression, or activation mitigated CoCl2-elicited inflammatory response. These observations were recapitulated in a mouse (C57BL/6J) model mimicking hypoxia, in which lung tissues presented higher levels of HIF-1α, proteasome activity, and inflammatory response, but lower levels of OGT (n = 5/group, hypoxia vs. normoxia, P < 0.05). However, administration of an activator of OGT (glucosamine: 1 mg/g/day, vehicle: saline, ip, 5 days) abolished the up-regulation of proteasome activity and inflammatory response (n = 5/group, the treated vs. untreated hypoxia groups, P < 0.05). CONCLUSIONS 26S proteasome-mediated OGT reduction contributed to hypoxia-induced vascular endothelial inflammatory response. Modulation of OGT may represent a new approach to treat diseases characterized by hypoxic inflammation.
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Affiliation(s)
- Hongtao Liu
- Section of Endocrinology and Diabetes, Department of Medicine, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Zhongxiao Wang
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Shujie Yu
- Section of Endocrinology and Diabetes, Department of Medicine, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Jian Xu
- Section of Endocrinology and Diabetes, Department of Medicine, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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Marunaka Y. Characteristics and Pharmacological Regulation of Epithelial Na+ Channel (ENaC) and Epithelial Na+ Transport. J Pharmacol Sci 2014. [DOI: 10.1254/jphs.14r01sr] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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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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