1
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Shin J, Hammer MJ, Paul SM, Conley YP, Harris C, Oppegaard K, Morse L, Cooper BA, Levine JD, Miaskowski C. Associations Between Preoperative Shortness of Breath and Potassium Channels Gene Variations in Women With Breast Cancer. Biol Res Nurs 2024:10998004241268088. [PMID: 39137431 DOI: 10.1177/10998004241268088] [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: 08/15/2024]
Abstract
OBJECTIVES Shortness of breath is a common symptom in patients with cancer. However, the mechanisms that underlie this troublesome symptom are poorly understood. Therefore, this study aimed to determine the prevalence of and associated risk factors for shortness of breath in women prior to breast cancer surgery and identify associations between shortness of breath and polymorphisms for potassium channel genes. METHODS Patients were recruited prior to breast cancer surgery and completed a self-report questionnaire on the occurrence of shortness of breath. Genotyping of single nucleotides polymorphism (SNPs) in potassium channel genes was performed using a custom array. Multiple logistic regression analyses were done to identify associations between the occurrence of shortness of breath and SNPs in ten candidate genes. RESULTS Of the 398 patients, 11.1% reported shortness of breath. These patients had a lower annual household income, a higher comorbidity burden, and a lower functional status. After controlling for functional status, comorbidity burden, genomic estimates of ancestry and self-reported race and ethnicity, the genetic associations that remained significant in the multiple regression analyses were for potassium voltage-gated channel subfamily D (KCND2) rs12673992, potassium voltage-gated channel modifier subfamily S (KCNS1) rs4499491, and potassium two pore channel subfamily K (KCNK2) rs4411107. CONCLUSIONS While these findings warrant replication, they suggest that alterations in potassium channel function may contribute to the occurrence of shortness of breath in women prior to breast cancer surgery.
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Affiliation(s)
- Joosun Shin
- Dana-Farber Cancer Institute, Boston, MA, USA
| | | | - Steven M Paul
- School of Nursing, University of California San Francisco, San Francisco, CA, USA
| | - Yvette P Conley
- School of Nursing, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carolyn Harris
- School of Nursing, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Lisa Morse
- School of Nursing, University of California San Francisco, San Francisco, CA, USA
| | - Bruce A Cooper
- School of Nursing, University of California San Francisco, San Francisco, CA, USA
| | - Jon D Levine
- VA Portland Health Care System, Portland, OR, USA
| | - Christine Miaskowski
- School of Nursing, University of California San Francisco, San Francisco, CA, USA
- School of Medicine, University of California San Francisco, San Francisco, CA, USA
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2
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Harvey BJ, McElvaney NG. Sex differences in airway disease: estrogen and airway surface liquid dynamics. Biol Sex Differ 2024; 15:56. [PMID: 39026347 PMCID: PMC11264786 DOI: 10.1186/s13293-024-00633-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 07/03/2024] [Indexed: 07/20/2024] Open
Abstract
Biological sex differences exist for many airway diseases in which females have either worse or better health outcomes. Inflammatory airway diseases such as cystic fibrosis (CF) and asthma display a clear male advantage in post-puberty while a female benefit is observed in asthma during the pre-puberty years. The influence of menstrual cycle stage and pregnancy on the frequency and severity of pulmonary exacerbations in CF and asthma point to a role for sex steroid hormones, particularly estrogen, in underpinning biological sex differences in these diseases. There are many ways by which estrogen may aggravate asthma and CF involving disturbances in airway surface liquid (ASL) dynamics, inappropriate hyper-immune and allergenic responses, as well as exacerbation of pathogen virulence. The deleterious effect of estrogen on pulmonary function in CF and asthma contrasts with the female advantage observed in airway diseases characterised by pulmonary edema such as pneumonia, acute respiratory distress syndrome (ARDS) and COVID-19. Airway surface liquid hypersecretion and alveolar flooding are hallmarks of ARDS and COVID-19, and contribute to the morbidity and mortality of severe forms of these diseases. ASL dynamics encompasses the intrinsic features of the thin lining of fluid covering the airway epithelium which regulate mucociliary clearance (ciliary beat, ASL height, volume, pH, viscosity, mucins, and channel activating proteases) in addition to innate defence mechanisms (pathogen virulence, cytokines, defensins, specialised pro-resolution lipid mediators, and metabolism). Estrogen regulation of ASL dynamics contributing to biological sex differences in CF, asthma and COVID-19 is a major focus of this review.
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Affiliation(s)
- Brian J Harvey
- Faculty of Medicine and Health Sciences, Royal College of Surgeons in Ireland, 126 St Stephens Green, Dublin 2, Ireland.
- Department of Medicine, RCSI ERC, Beaumont Hospital, Dublin 2, Ireland.
| | - Noel G McElvaney
- Faculty of Medicine and Health Sciences, Royal College of Surgeons in Ireland, 126 St Stephens Green, Dublin 2, Ireland
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3
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Aubin Vega M, Girault A, Meunier É, Chebli J, Privé A, Robichaud A, Adam D, Brochiero E. Function of KvLQT1 potassium channels in a mouse model of bleomycin-induced acute lung injury. Front Physiol 2024; 15:1345488. [PMID: 38444763 PMCID: PMC10912346 DOI: 10.3389/fphys.2024.1345488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/30/2024] [Indexed: 03/07/2024] Open
Abstract
Acute respiratory distress syndrome (ARDS) is characterized by an exacerbated inflammatory response, severe damage to the alveolar-capillary barrier and a secondary infiltration of protein-rich fluid into the airspaces, ultimately leading to respiratory failure. Resolution of ARDS depends on the ability of the alveolar epithelium to reabsorb lung fluid through active transepithelial ion transport, to control the inflammatory response, and to restore a cohesive and functional epithelium through effective repair processes. Interestingly, several lines of evidence have demonstrated the important role of potassium (K+) channels in the regulation of epithelial repair processes. Furthermore, these channels have previously been shown to be involved in sodium/fluid absorption across alveolar epithelial cells, and we have recently demonstrated the contribution of KvLQT1 channels to the resolution of thiourea-induced pulmonary edema in vivo. The aim of our study was to investigate the role of the KCNQ1 pore-forming subunit of KvLQT1 channels in the outcome of ARDS parameters in a model of acute lung injury (ALI). We used a molecular approach with KvLQT1-KO mice challenged with bleomycin, a well-established ALI model that mimics the key features of the exudative phase of ARDS on day 7. Our data showed that KvLQT1 deletion exacerbated the negative outcome of bleomycin on lung function (resistance, elastance and compliance). An alteration in the profile of infiltrating immune cells was also observed in KvLQT1-KO mice while histological analysis showed less interstitial and/or alveolar inflammatory response induced by bleomycin in KvLQT1-KO mice. Finally, a reduced repair rate of KvLQT1-KO alveolar cells after injury was observed. This work highlights the complex contribution of KvLQT1 in the development and resolution of ARDS parameters in a model of ALI.
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Affiliation(s)
- Mélissa Aubin Vega
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Alban Girault
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
- Laboratoire de Physiologie Cellulaire et Moléculaire (LPCM UR UPJV 4667), Amiens, France
| | - Émilie Meunier
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Jasmine Chebli
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Anik Privé
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
| | | | - Damien Adam
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Emmanuelle Brochiero
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
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4
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Harvey BJ. Molecular mechanisms of dexamethasone actions in COVID-19: Ion channels and airway surface liquid dynamics. Steroids 2024; 202:109348. [PMID: 38049079 DOI: 10.1016/j.steroids.2023.109348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/23/2023] [Accepted: 11/28/2023] [Indexed: 12/06/2023]
Abstract
The COVID-19 pandemic has been a global health crisis of unprecedented magnitude. In the battle against the SARS-CoV-2 coronavirus, dexamethasone, a widely used corticosteroid with potent anti-inflammatory properties, has emerged as a promising therapy in the fight against severe COVID-19. Dexamethasone is a synthetic glucocorticoid that exerts its therapeutic effects by suppressing the immune system and reducing inflammation. In the context of COVID-19, the severe form of the disease is often characterized by a hyperactive immune response, known as a cytokine storm. Dexamethasone anti-inflammatory properties make it a potent tool in modulating this exaggerated immune response. Lung inflammation may lead to excessive fluid accumulation in the airways which can reduce gas exchange and mucociliary clearance. Pulmonary oedema and flooding of the airways are hallmarks of severe COVID-19 lung disease. The volume of airway surface liquid is determined by a delicate balance of salt and water secretion and absorption across the airway epithelium. In addition to its anti-inflammatory actions, dexamethasone modulates the activity of ion channels which regulate electrolyte and water transport across the airway epithelium. The observations of dexamethasone activation of sodium ion absorption via ENaC Na+ channels and inhibition of chloride ion secretion via CFTR Cl- channels to decrease airway surface liquid volume indicate a novel therapeutic action of the glucocorticoid to reverse airway flooding. This brief review delves into the early non-genomic and late genomic signaling mechanisms of dexamethasone regulation of ion channels and airway surface liquid dynamics, shedding light on the molecular mechanisms underpinning the action of the glucocorticoid in managing COVID-19.
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Affiliation(s)
- Brian J Harvey
- Faculty of Medicine, Royal College of Surgeons in Ireland, RCSI University of Medicine and Health Sciences, Dublin 2, Ireland; Centro de Estudios Cientificos, Valdivia, Chile.
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5
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Hao X, Yang Y, Liu J, Zhang D, Ou M, Ke B, Zhu T, Zhou C. The Modulation by Anesthetics and Analgesics of Respiratory Rhythm in the Nervous System. Curr Neuropharmacol 2024; 22:217-240. [PMID: 37563812 PMCID: PMC10788885 DOI: 10.2174/1570159x21666230810110901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 04/27/2023] [Accepted: 02/28/2023] [Indexed: 08/12/2023] Open
Abstract
Rhythmic eupneic breathing in mammals depends on the coordinated activities of the neural system that sends cranial and spinal motor outputs to respiratory muscles. These outputs modulate lung ventilation and adjust respiratory airflow, which depends on the upper airway patency and ventilatory musculature. Anesthetics are widely used in clinical practice worldwide. In addition to clinically necessary pharmacological effects, respiratory depression is a critical side effect induced by most general anesthetics. Therefore, understanding how general anesthetics modulate the respiratory system is important for the development of safer general anesthetics. Currently used volatile anesthetics and most intravenous anesthetics induce inhibitory effects on respiratory outputs. Various general anesthetics produce differential effects on respiratory characteristics, including the respiratory rate, tidal volume, airway resistance, and ventilatory response. At the cellular and molecular levels, the mechanisms underlying anesthetic-induced breathing depression mainly include modulation of synaptic transmission of ligand-gated ionotropic receptors (e.g., γ-aminobutyric acid, N-methyl-D-aspartate, and nicotinic acetylcholine receptors) and ion channels (e.g., voltage-gated sodium, calcium, and potassium channels, two-pore domain potassium channels, and sodium leak channels), which affect neuronal firing in brainstem respiratory and peripheral chemoreceptor areas. The present review comprehensively summarizes the modulation of the respiratory system by clinically used general anesthetics, including the effects at the molecular, cellular, anatomic, and behavioral levels. Specifically, analgesics, such as opioids, which cause respiratory depression and the "opioid crisis", are discussed. Finally, underlying strategies of respiratory stimulation that target general anesthetics and/or analgesics are summarized.
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Affiliation(s)
- Xuechao Hao
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Yaoxin Yang
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Jin Liu
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Donghang Zhang
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Mengchan Ou
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Bowen Ke
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Tao Zhu
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
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6
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Russell NX, Burra K, Shah RM, Bottasso-Arias N, Mohanakrishnan M, Snowball J, Ediga HH, Madala SK, Sinner D. Wnt signaling regulates ion channel expression to promote smooth muscle and cartilage formation in developing mouse trachea. Am J Physiol Lung Cell Mol Physiol 2023; 325:L788-L802. [PMID: 37873566 PMCID: PMC11068408 DOI: 10.1152/ajplung.00024.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 08/28/2023] [Accepted: 10/15/2023] [Indexed: 10/25/2023] Open
Abstract
Ion channels play critical roles in the physiology and function of the nervous system and contractile tissue; however, their role in noncontractile tissue and embryonic development has yet to be understood. Tracheobronchomalacia (TBM) and complete tracheal rings (CTR) are disorders affecting the muscle and cartilage of the trachea and bronchi, whose etiology remains poorly understood. We demonstrated that trachealis muscle organization and polarity are disrupted after epithelial ablation of Wntless (Wls), a cargo receptor critical for the Wnt signaling pathway, in developing trachea. The phenotype resembles the anomalous trachealis muscle observed after deletion of ion channel encoding genes in developing mouse trachea. We sought to investigate whether and how the deletion of Wls affects ion channels during tracheal development. We hypothesize that Wnt signaling influences the expression of ion channels to promote trachealis muscle cell assembly and patterning. Deleting Wls in developing trachea causes differential regulation of genes mediating actin binding, cytoskeleton organization, and potassium ion channel activity. Wnt signaling regulates the expression of Kcnj13, Kcnd3, Kcnj8, and Abcc9 as demonstrated by in vitro studies and in vivo analysis in Wnt5a and β-catenin-deficient tracheas. Pharmacological inhibition of potassium ion channels and Wnt signaling impaired contractility of developing trachealis smooth muscle and formation of cartilaginous mesenchymal condensation. Thus, in mice, epithelial-induced Wnt/β-catenin signaling mediates trachealis muscle and cartilage development via modulation of ion channel expression, promoting trachealis muscle architecture, contractility, and cartilaginous extracellular matrix. In turn, ion channel activity may influence tracheal morphogenesis underlying TBM and CTR.NEW & NOTEWORTHY Ion channels play critical roles in the physiology and function of the nervous system and contractile tissue; however, their role in noncontractile tissue and embryonic development has yet to be understood. In this study, we focused on the role of ion channels in the differentiation and patterning of the large airways of the developing respiratory tract. We identify a mechanism by which Wnt-beta-catenin signaling controls levels of ion channel-encoding genes to promote tracheal differentiation.
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Affiliation(s)
- Nicholas X Russell
- Neonatology and Pulmonary Biology Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati Honors Program, Cincinnati, Ohio, United States
| | - Kaulini Burra
- Neonatology and Pulmonary Biology Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Ronak M Shah
- Neonatology and Pulmonary Biology Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati Honors Program, Cincinnati, Ohio, United States
| | - Natalia Bottasso-Arias
- Neonatology and Pulmonary Biology Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Megha Mohanakrishnan
- Neonatology and Pulmonary Biology Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati Honors Program, Cincinnati, Ohio, United States
| | - John Snowball
- Neonatology and Pulmonary Biology Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
| | - Harshavardhana H Ediga
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| | - Satish K Madala
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| | - Debora Sinner
- Neonatology and Pulmonary Biology Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati, College of Medicine, Cincinnati, Ohio, United States
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7
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Russell NX, Burra K, Shah R, Bottasso-Arias N, Mohanakrishnan M, Snowball J, Ediga HH, Madala SK, Sinner D. Wnt signaling regulates ion channel expression to promote smooth muscle and cartilage formation in developing mouse trachea. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.10.523309. [PMID: 36711918 PMCID: PMC9882072 DOI: 10.1101/2023.01.10.523309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Ion channels play critical roles in the physiology and function of the nervous system and contractile tissue; however, their role in non-contractile tissue and embryonic development has yet to be understood. Tracheobronchomalacia (TBM) and complete tracheal rings (CTR) are disorders affecting the muscle and cartilage of the trachea and bronchi, whose etiology remains poorly understood. We demonstrated that trachealis muscle organization and polarity are disrupted after epithelial ablation of Wls, a cargo receptor critical for the Wnt signaling pathway, in developing trachea. The phenotype resembles the anomalous trachealis muscle observed after deletion of ion channel encoding genes in developing mouse trachea. We sought to investigate whether and how the deletion of Wls affects ion channels during tracheal development. We hypothesize that Wnt signaling influences the expression of ion channels to promote trachealis muscle cell assembly and patterning. Deleting Wls in developing trachea causes differential regulation of genes mediating actin binding, cytoskeleton organization, and potassium ion channel activity. Wnt signaling regulated expression of Kcnj13, Kcnd3, Kcnj8, and Abcc9 as demonstrated by in vitro studies and in vivo analysis in Wnt5a and β-catenin deficient tracheas. Pharmacological inhibition of potassium ion channels and Wnt signaling impaired contractility of developing trachealis smooth muscle and formation of cartilaginous mesenchymal condensation. Thus, in mice, epithelial-induced Wnt/β-catenin signaling mediates trachealis muscle and cartilage development via modulation of ion channel expression, promoting trachealis muscle architecture, contractility, and cartilaginous extracellular matrix. In turn, ion channel activity may influence tracheal morphogenesis underlying TBM and CTR.
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Affiliation(s)
- Nicholas X. Russell
- Neonatology and Pulmonary Biology Perinatal Institute. Cincinnati Children’s Hospital Medical Center and University of Cincinnati Honors Program
| | - Kaulini Burra
- Neonatology and Pulmonary Biology Perinatal Institute. Cincinnati Children’s Hospital Medical Center. Current affiliation: Nationwide Children’s Hospital Columbus OH
| | - Ronak Shah
- Neonatology and Pulmonary Biology Perinatal Institute. Cincinnati Children’s Hospital Medical Center and University of Cincinnati Honors Program Current Affiliation: Renaissance School of Medicine at Stony Brook University
| | - Natalia Bottasso-Arias
- Neonatology and Pulmonary Biology Perinatal Institute. Cincinnati Children’s Hospital Medical Center
| | - Megha Mohanakrishnan
- Neonatology and Pulmonary Biology Perinatal Institute. Cincinnati Children’s Hospital Medical Center and University of Cincinnati Honors Program
| | - John Snowball
- Neonatology and Pulmonary Biology Perinatal Institute. Cincinnati Children’s Hospital Medical Center. Current affiliation: P&G Cincinnati, OH
| | - Harshavardhana H. Ediga
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, University of Cincinnati College of Medicine
| | - Satish K Madala
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, University of Cincinnati College of Medicine
| | - Debora Sinner
- Neonatology and Pulmonary Biology Perinatal Institute. Cincinnati Children’s Hospital Medical Center and University of Cincinnati, College of Medicine
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8
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Orfali R, AlFaiz A, Rahman MA, Lau L, Nam YW, Zhang M. K Ca2 and K Ca3.1 Channels in the Airways: A New Therapeutic Target. Biomedicines 2023; 11:1780. [PMID: 37509419 PMCID: PMC10376499 DOI: 10.3390/biomedicines11071780] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/08/2023] [Accepted: 06/13/2023] [Indexed: 07/30/2023] Open
Abstract
K+ channels are involved in many critical functions in lung physiology. Recently, the family of Ca2+-activated K+ channels (KCa) has received more attention, and a massive amount of effort has been devoted to developing selective medications targeting these channels. Within the family of KCa channels, three small-conductance Ca2+-activated K+ (KCa2) channel subtypes, together with the intermediate-conductance KCa3.1 channel, are voltage-independent K+ channels, and they mediate Ca2+-induced membrane hyperpolarization. Many KCa2 channel members are involved in crucial roles in physiological and pathological systems throughout the body. In this article, different subtypes of KCa2 and KCa3.1 channels and their functions in respiratory diseases are discussed. Additionally, the pharmacology of the KCa2 and KCa3.1 channels and the link between these channels and respiratory ciliary regulations will be explained in more detail. In the future, specific modulators for small or intermediate Ca2+-activated K+ channels may offer a unique therapeutic opportunity to treat muco-obstructive lung diseases.
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Affiliation(s)
- Razan Orfali
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA 92618, USA
- Biomedical Research Administration, Research Centre, King Fahad Medical City, Riyadh Second Health Cluster, Riyadh 12231, Saudi Arabia
| | - Ali AlFaiz
- Biomedical Research Administration, Research Centre, King Fahad Medical City, Riyadh Second Health Cluster, Riyadh 12231, Saudi Arabia
| | - Mohammad Asikur Rahman
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA 92618, USA
| | - Liz Lau
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA 92618, USA
| | - Young-Woo Nam
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA 92618, USA
| | - Miao Zhang
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA 92618, USA
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9
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Canella R, Benedusi M, Vallese A, Pecorelli A, Guiotto A, Ferrara F, Rispoli G, Cervellati F, Valacchi G. The role of potassium current in the pulmonary response to environmental oxidative stress. Arch Biochem Biophys 2023; 737:109534. [PMID: 36740034 DOI: 10.1016/j.abb.2023.109534] [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: 07/14/2022] [Revised: 11/30/2022] [Accepted: 01/24/2023] [Indexed: 02/05/2023]
Abstract
Exposure of human lung epithelial cells (A549 cell line) to the oxidant pollutant ozone (O3) alters cell membrane currents inducing its decrease, when the cell undergoes to a voltage-clamp protocol ranging from -90 to +70mV. The membrane potential of these cells is mainly maintained by the interplay of potassium and chloride currents. Our previous studies indicated the ability of O3 to activate ORCC (Outward Rectifier Chloride Channel) and consequently increases the chloride current. In this paper our aim was to understand the response of potassium current to oxidative stress challenge and to identify the kind potassium channel involved in O3 induced current changes. After measuring the total membrane current using an intracellular solution with or without potassium ions, we obtained the contribution of potassium to the overall membrane current in control condition by a mathematical approach. Repeating these experiments after O3 treatment we observed a significant decrease of Ipotassium. Treatment of the cells with Iberiotoxin (IbTx), a specific inhibitor of BK channel, we were able to verify the presence and the functionality of BK channels. In addition, the administration of 4-Aminopyridine (an inhibitor of voltage dependent K channels but not BK channels) and Tetraethylammonium (TEA) before and after O3 treatment we observed the formation of BK oxidative post-translation modifications. Our data suggest that O3 is able to inhibit potassium current by targeting BK channel. Further studies are needed to better clarify the role of this BK channel and its interplay with the other membrane channels under oxidative stress conditions. These findings can contribute to identify the biomolecular pathway induced by O3 allowing a possible pharmacological intervention against oxidative stress damage in lung tissue.
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Affiliation(s)
- Rita Canella
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy.
| | - Mascia Benedusi
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy
| | - Andrea Vallese
- Department of Environmental Sciences and Prevention, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy
| | - Alessandra Pecorelli
- Department of Environmental Sciences and Prevention, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy
| | - Anna Guiotto
- Department of Environmental Sciences and Prevention, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy
| | - Francesca Ferrara
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy
| | - Giorgio Rispoli
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy
| | - Franco Cervellati
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy
| | - Giuseppe Valacchi
- Department of Environmental Sciences and Prevention, University of Ferrara, Via L. Borsari, 46, Ferrara, Italy; NC State University, Plants for Human Health Institute, Animal Science Dept. NC Research Campus 600 Laureate Way, Kannapolis, NC, 28081, USA; Department of Food and Nutrition, Kyung Hee University, Seoul, South Korea.
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10
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Aubin Vega M, Girault A, Adam D, Chebli J, Privé A, Maillé É, Robichaud A, Brochiero E. Impact of KvLQT1 potassium channel modulation on alveolar fluid homeostasis in an animal model of thiourea-induced lung edema. Front Physiol 2023; 13:1069466. [PMID: 36699692 PMCID: PMC9868633 DOI: 10.3389/fphys.2022.1069466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
Alveolar ion and fluid absorption is essential for lung homeostasis in healthy conditions as well as for the resorption of lung edema, a key feature of acute respiratory distress syndrome. Liquid absorption is driven by active transepithelial sodium transport, through apical ENaC Na+ channels and basolateral Na+/K+-ATPase. Our previous work unveiled that KvLQT1 K+ channels also participate in the control of Na+/liquid absorption in alveolar epithelial cells. Our aim was to further investigate the function of KvLQT1 channels and their interplay with other channels/transporters involved in ion/liquid transport in vivo using adult wild-type (WT) and KvLQT1 knock-out (KO) mice under physiological conditions and after thiourea-induced lung edema. A slight but significant increase in water lung content (WLC) was observed in naïve KvLQT1-KO mice, relative to WT littermates, whereas lung function was generally preserved and histological structure unaltered. Following thiourea-induced lung edema, KvLQT1-KO did not worsen WLC or lung function. Similarly, lung edema was not aggravated by the administration of a KvLQT1 inhibitor (chromanol). However, KvLQT1 activation (R-L3) significantly reduced WLC in thiourea-challenged WT mice. The benefits of R-L3 were prevented in KO or chromanol-treated WT mice. Furthermore, R-L3 treatment had no effect on thiourea-induced endothelial barrier alteration but restored or enhanced the levels of epithelial alveolar AQP5, Na+/K+-ATPase, and ENaC expressions. Altogether, the results indicate the benefits of KvLQT1 activation in the resolution of lung edema, probably through the observed up-regulation of epithelial alveolar channels/transporters involved in ion/water transport.
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Affiliation(s)
- Mélissa Aubin Vega
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada,Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Alban Girault
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada,Département de Médecine, Université de Montréal, Montréal, QC, Canada,Laboratoire de Physiologie Cellulaire et Moléculaire (LPCM), Amiens, France
| | - Damien Adam
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada,Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Jasmine Chebli
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada,Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Anik Privé
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Émilie Maillé
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
| | | | - Emmanuelle Brochiero
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada,Département de Médecine, Université de Montréal, Montréal, QC, Canada,*Correspondence: Emmanuelle Brochiero,
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11
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Gonçalves AN, Moura RS, Correia-Pinto J, Nogueira-Silva C. Intraluminal chloride regulates lung branching morphogenesis: involvement of PIEZO1/PIEZO2. Respir Res 2023; 24:42. [PMID: 36740669 PMCID: PMC9901166 DOI: 10.1186/s12931-023-02328-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 01/13/2023] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Clinical and experimental evidence shows lung fluid volume as a modulator of fetal lung growth with important value in treating fetal lung hypoplasia. Thus, understanding the mechanisms underlying these morphological dynamics has been the topic of multiple investigations with, however, limited results, partially due to the difficulty of capturing or recapitulating these movements in the lab. In this sense, this study aims to establish an ex vivo model allowing the study of lung fluid function in branching morphogenesis and identify the subsequent molecular/ cellular mechanisms. METHODS Ex vivo lung explant culture was selected as a model to study branching morphogenesis, and intraluminal injections were performed to change the composition of lung fluid. Distinct chloride (Cl-) concentrations (5.8, 29, 143, and 715 mM) or Cl- channels inhibitors [antracene-9-carboxylic acid (A9C), cystic fibrosis transmembrane conductance regulator inhibitor172 (CFTRinh), and calcium-dependent Cl- channel inhibitorA01 (CaCCinh)] were injected into lung lumen at two timepoints, day0 (D0) and D2. At D4, morphological and molecular analyses were performed in terms of branching morphogenesis, spatial distribution (immunofluorescence), and protein quantification (western blot) of mechanoreceptors (PIEZO1 and PIEZO2), neuroendocrine (bombesin, ghrelin, and PGP9.5) and smooth muscle [alpha-smooth muscle actin (α-SMA) and myosin light chain 2 (MLC2)] markers. RESULTS For the first time, we described effective intraluminal injections at D0 and D2 and demonstrated intraluminal movements at D4 in ex vivo lung explant cultures. Through immunofluorescence assay in in vivo and ex vivo branching morphogenesis, we show that PGP9.5 colocalizes with PIEZO1 and PIEZO2 receptors. Fetal lung growth is increased at higher [Cl-], 715 mM Cl-, through the overexpression of PIEZO1, PIEZO2, ghrelin, bombesin, MLC2, and α-SMA. In contrast, intraluminal injection of CFTRinh or CaCCinh decreases fetal lung growth and the expression of PIEZO1, PIEZO2, ghrelin, bombesin, MLC2, and α-SMA. Finally, the inhibition of PIEZO1/PIEZO2 by GsMTx4 decreases branching morphogenesis and ghrelin, bombesin, MLC2, and α-SMA expression in an intraluminal injection-independent manner. CONCLUSIONS Our results identify PIEZO1/PIEZO2 expressed in neuroendocrine cells as a regulator of fetal lung growth induced by lung fluid.
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Affiliation(s)
- Ana N. Gonçalves
- grid.10328.380000 0001 2159 175XSchool of Medicine, Life and Health Sciences Research Institute (ICVS), University of Minho, Campus de Gualtar, Gualtar, 4710-057 Braga, Portugal ,grid.10328.380000 0001 2159 175XLife and Health Sciences Research Institute/3B’s-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rute S. Moura
- grid.10328.380000 0001 2159 175XSchool of Medicine, Life and Health Sciences Research Institute (ICVS), University of Minho, Campus de Gualtar, Gualtar, 4710-057 Braga, Portugal ,grid.10328.380000 0001 2159 175XLife and Health Sciences Research Institute/3B’s-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Jorge Correia-Pinto
- grid.10328.380000 0001 2159 175XSchool of Medicine, Life and Health Sciences Research Institute (ICVS), University of Minho, Campus de Gualtar, Gualtar, 4710-057 Braga, Portugal ,grid.10328.380000 0001 2159 175XLife and Health Sciences Research Institute/3B’s-PT Government Associate Laboratory, Braga/Guimarães, Portugal ,Department of Pediatric Surgery, Hospital de Braga, Braga, Portugal
| | - Cristina Nogueira-Silva
- School of Medicine, Life and Health Sciences Research Institute (ICVS), University of Minho, Campus de Gualtar, Gualtar, 4710-057, Braga, Portugal. .,Life and Health Sciences Research Institute/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal. .,Department of Obstetrics and Gynecology, Hospital de Braga, Braga, Portugal.
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12
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Velasco E, Delicado‐Miralles M, Hellings PW, Gallar J, Van Gerven L, Talavera K. Epithelial and sensory mechanisms of nasal hyperreactivity. Allergy 2022; 77:1450-1463. [PMID: 35174893 DOI: 10.1111/all.15259] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 02/06/2022] [Accepted: 02/14/2022] [Indexed: 11/28/2022]
Abstract
"Nasal hyperreactivity" is a key feature in various phenotypes of upper airway diseases, whereby reactions of the nasal epithelium to diverse chemical and physical stimuli are exacerbated. In this review, we illustrate how nasal hyperreactivity can result from at least three types of mechanisms: (1) impaired barrier function, (2) hypersensitivity to external and endogenous stimuli, and (3) potentiation of efferent systems. We describe the known molecular basis of hyperreactivity related to the functional impairment of epithelial cells and somatosensory innervation, and indicate that the thermal, chemical, and mechanical sensors determining hyperreactivity in humans remain to be identified. We delineate research directions that may provide new insights into nasal hyperreactivity associated with rhinitis/rhinosinusitis pathophysiology and therapeutics. The elucidation of the molecular mechanisms underlying nasal hyperreactivity is essential for the treatment of rhinitis according to the precepts of precision medicine.
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Affiliation(s)
- Enrique Velasco
- Instituto de Neurociencias Universidad Miguel Hernández‐CSIC San Juan de Alicante Spain
- The European University of Brain and Technology‐Neurotech EU San Juan de Alicante Spain
| | | | - Peter W. Hellings
- Department of Otorhinolaryngology University Hospitals Leuven Leuven Belgium
| | - Juana Gallar
- Instituto de Neurociencias Universidad Miguel Hernández‐CSIC San Juan de Alicante Spain
- The European University of Brain and Technology‐Neurotech EU San Juan de Alicante Spain
- Instituto de Investigación Sanitaria y Biomédica de Alicante San Juan de Alicante Spain
| | - Laura Van Gerven
- Department of Otorhinolaryngology University Hospitals Leuven Leuven Belgium
- Department of Microbiology, Immunology and transplantation, Allergy and Clinical Immunology Research Unit KU Leuven Leuven Belgium
- Department of Neurosciences, Experimental Otorhinolaryngology, Rhinology Research KU Leuven Leuven Belgium
| | - Karel Talavera
- Laboratory of Ion Channel Research Department of Cellular and Molecular Medicine KU Leuven, VIB‐KU Leuven Center for Brain & Disease Research Leuven Belgium
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13
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Abundant Monovalent Ions as Environmental Signposts for Pathogens during Host Colonization. Infect Immun 2021; 89:IAI.00641-20. [PMID: 33526568 DOI: 10.1128/iai.00641-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Host colonization by a pathogen requires proper sensing and response to local environmental cues, to ensure adaptation and continued survival within the host. The ionic milieu represents a critical potential source of environmental cues, and indeed, there has been extensive study of the interplay between host and pathogen in the context of metals such as iron, zinc, and manganese, vital ions that are actively sequestered by the host. The inherent non-uniformity of the ionic milieu also extends, however, to "abundant" ions such as chloride and potassium, whose concentrations vary greatly between tissue and cellular locations, and with the immune response. Despite this, the concept of abundant ions as environmental cues and key players in host-pathogen interactions is only just emerging. Focusing on chloride and potassium, this review brings together studies across multiple bacterial and parasitic species that have begun to define both how these abundant ions are exploited as cues during host infection, and how they can be actively manipulated by pathogens during host colonization. The close links between ion homeostasis and sensing/response to different ionic signals, and the importance of studying pathogen response to cues in combination, are also discussed, while considering the fundamental insight still to be uncovered from further studies in this nascent area of inquiry.
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14
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Vega G, Guequén A, Philp AR, Gianotti A, Arzola L, Villalón M, Zegarra-Moran O, Galietta LJ, Mall MA, Flores CA. Lack of Kcnn4 improves mucociliary clearance in muco-obstructive lung disease. JCI Insight 2020; 5:140076. [PMID: 32814712 PMCID: PMC7455130 DOI: 10.1172/jci.insight.140076] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
Airway mucociliary clearance (MCC) is the main mechanism of lung defense keeping airways free of infection and mucus obstruction. Airway surface liquid volume, ciliary beating, and mucus are central for proper MCC and critically regulated by sodium absorption and anion secretion. Impaired MCC is a key feature of muco-obstructive diseases. The calcium-activated potassium channel KCa.3.1, encoded by Kcnn4, participates in ion secretion, and studies showed that its activation increases Na+ absorption in airway epithelia, suggesting that KCa3.1-induced hyperpolarization was sufficient to drive Na+ absorption. However, its role in airway epithelium is not fully understood. We aimed to elucidate the role of KCa3.1 in MCC using a genetically engineered mouse. KCa3.1 inhibition reduced Na+ absorption in mouse and human airway epithelium. Furthermore, the genetic deletion of Kcnn4 enhanced cilia beating frequency and MCC ex vivo and in vivo. Kcnn4 silencing in the Scnn1b-transgenic mouse (Scnn1btg/+), a model of muco-obstructive lung disease triggered by increased epithelial Na+ absorption, improved MCC, reduced Na+ absorption, and did not change the amount of mucus but did reduce mucus adhesion, neutrophil infiltration, and emphysema. Our data support that KCa3.1 inhibition attenuated muco-obstructive disease in the Scnn1btg/+ mice. K+ channel modulation may be a therapeutic strategy to treat muco-obstructive lung diseases. Silencing the calcium-activated potassium channel KCa.3.1 improves mucociliary clearance in muco-obstructive lung disease by decreasing sodium absorption in the airways.
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Affiliation(s)
| | - Anita Guequén
- Centro de Estudios Científicos, Valdivia, Chile.,Universidad Austral de Chile, Valdivia, Chile
| | - Amber R Philp
- Centro de Estudios Científicos, Valdivia, Chile.,Universidad Austral de Chile, Valdivia, Chile
| | | | - Llilian Arzola
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Manuel Villalón
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Luis Jv Galietta
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Department of Translational Medical Sciences, University of Naples Federico II, Naples, Italy
| | - Marcus A Mall
- Department of Pediatric Pulmonology, Immunology and Critical Care Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany.,German Center for Lung Research, Berlin, Germany
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15
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Mondejar-Parreño G, Perez-Vizcaino F, Cogolludo A. Kv7 Channels in Lung Diseases. Front Physiol 2020; 11:634. [PMID: 32676036 PMCID: PMC7333540 DOI: 10.3389/fphys.2020.00634] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/18/2020] [Indexed: 12/23/2022] Open
Abstract
Lung diseases constitute a global health concern causing disability. According to WHO in 2016, respiratory diseases accounted for 24% of world population mortality, the second cause of death after cardiovascular diseases. The Kv7 channels family is a group of voltage-dependent K+ channels (Kv) encoded by KCNQ genes that are involved in various physiological functions in numerous cell types, especially, cardiac myocytes, smooth muscle cells, neurons, and epithelial cells. Kv7 channel α-subunits are regulated by KCNE1–5 ancillary β-subunits, which modulate several characteristics of Kv7 channels such as biophysical properties, cell-location, channel trafficking, and pharmacological sensitivity. Kv7 channels are mainly expressed in two large groups of lung tissues: pulmonary arteries (PAs) and bronchial tubes. In PA, Kv7 channels are expressed in pulmonary artery smooth muscle cells (PASMCs); while in the airway (trachea, bronchus, and bronchioles), Kv7 channels are expressed in airway smooth muscle cells (ASMCs), airway epithelial cells (AEPs), and vagal airway C-fibers (VACFs). The functional role of Kv7 channels may vary depending on the cell type. Several studies have demonstrated that the impairment of Kv7 channel has a strong impact on pulmonary physiology contributing to the pathophysiology of different respiratory diseases such as cystic fibrosis, asthma, chronic obstructive pulmonary disease, chronic coughing, lung cancer, and pulmonary hypertension. Kv7 channels are now recognized as playing relevant physiological roles in many tissues, which have encouraged the search for Kv7 channel modulators with potential therapeutic use in many diseases including those affecting the lung. Modulation of Kv7 channels has been proposed to provide beneficial effects in a number of lung conditions. Therefore, Kv7 channel openers/enhancers or drugs acting partly through these channels have been proposed as bronchodilators, expectorants, antitussives, chemotherapeutics and pulmonary vasodilators.
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Affiliation(s)
- Gema Mondejar-Parreño
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain.,Ciber Enfermedades Respiratorias (Ciberes), Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain
| | - Francisco Perez-Vizcaino
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain.,Ciber Enfermedades Respiratorias (Ciberes), Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain
| | - Angel Cogolludo
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain.,Ciber Enfermedades Respiratorias (Ciberes), Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain
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16
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Panou MM, Antoni M, Morgan EL, Loundras EA, Wasson CW, Welberry-Smith M, Mankouri J, Macdonald A. Glibenclamide inhibits BK polyomavirus infection in kidney cells through CFTR blockade. Antiviral Res 2020; 178:104778. [PMID: 32229236 PMCID: PMC7322401 DOI: 10.1016/j.antiviral.2020.104778] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/07/2020] [Accepted: 03/18/2020] [Indexed: 02/08/2023]
Abstract
BK polyomavirus (BKPyV) is a ubiquitous pathogen in the human population that is asymptomatic in healthy individuals, but can be life-threatening in those undergoing kidney transplant. To-date, no vaccines or anti-viral therapies are available to treat human BKPyV infections. New therapeutic strategies are urgently required. In this study, using a rational pharmacological screening regimen of known ion channel modulating compounds, we show that BKPyV requires cystic fibrosis transmembrane conductance regulator (CFTR) activity to infect primary renal proximal tubular epithelial cells. Disrupting CFTR function through treatment with the clinically available drug glibenclamide, the CFTR inhibitor CFTR172, or CFTR-silencing, all reduced BKPyV infection. Specifically, time of addition assays and the assessment of the exposure of VP2/VP3 minor capsid proteins indicated a role for CFTR during BKPyV transport to the endoplasmic reticulum, an essential step during the early stages of BKPyV infection. We thus establish CFTR as an important host-factor in the BKPyV life cycle and reveal CFTR modulators as potential anti-BKPyV therapies. BK polyomavirus (BKPyV) is life-threatening in those undergoing kidney transplant. BKPyV requires CFTR to infect primary kidney cells. Disrupting CFTR function pharmacologically reduces BKPyV infection. CFTR is required during BKPyV transport to the endoplasmic reticulum.
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Affiliation(s)
- Margarita-Maria Panou
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom
| | - Michelle Antoni
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom
| | - Ethan L Morgan
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom
| | - Eleni-Anna Loundras
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom
| | - Christopher W Wasson
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom
| | | | - Jamel Mankouri
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom.
| | - Andrew Macdonald
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom.
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17
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New ISE-Based Apparatus for Na +, K +, Cl -, pH and Transepithelial Potential Difference Real-Time Simultaneous Measurements of Ion Transport across Epithelial Cells Monolayer⁻Advantages and Pitfalls. SENSORS 2019; 19:s19081881. [PMID: 31009998 PMCID: PMC6515391 DOI: 10.3390/s19081881] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/14/2019] [Accepted: 04/18/2019] [Indexed: 12/18/2022]
Abstract
Cystic Fibrosis (CF) is the most common fatal human genetic disease, which is caused by a defect in an anion channel protein (CFTR) that affects ion and water transport across the epithelium. We devised an apparatus to enable the measurement of concentration changes of sodium, potassium, chloride, pH, and transepithelial potential difference by means of ion-selective electrodes that were placed on both sides of a 16HBE14σ human bronchial epithelial cell line that was grown on a porous support. Using flat miniaturized ISE electrodes allows for reducing the medium volume adjacent to cells to approximately 20 μL and detecting changes in ion concentrations that are caused by transport through the cell layer. In contrast to classic electrochemical measurements, in our experiments neither the calibration of electrodes nor the interpretation of results is simple. The calibration solutions might affect cell physiology, the medium composition might change the direction of actions of the membrane channels and transporters, and water flow that might trigger or cut off the transport pathways accompanies the transport of ions. We found that there is an electroneutral transport of sodium chloride in both directions of the cell monolayer in the isosmotic transepithelial concentration gradient of sodium or chloride ions. The ions and water are transported as an isosmotic solution of 145 mM of NaCl.
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18
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Canella R, Martini M, Cavicchio C, Cervellati F, Benedusi M, Valacchi G. Involvement of the TREK-1 channel in human alveolar cell membrane potential and its regulation by inhibitors of the chloride current. J Cell Physiol 2019; 234:17704-17713. [PMID: 30805940 DOI: 10.1002/jcp.28396] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 01/03/2019] [Accepted: 01/10/2019] [Indexed: 12/14/2022]
Abstract
K+ channels of the alveolar epithelium control the driving force acting on the ionic and solvent flow through the cell membrane contributing to the maintenance of cell volume and the constitution of epithelial lining fluid. In the present work, we analyze the effect of the Cl- channel inhibitors: (4-[(2-butyl-6,7-dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-inden-5-yl)oxy] butanoic acid (DCPIB) and 9-anthracenecarboxylic acid (9-AC) on the total current in a type II pneumocytes (A549 cell line) model by patch clamp, immunocytochemical, and gene knockdown techniques. We noted that DCPIB and 9-AC promote the activation of K conductance. In fact, they significantly increase the intensity of the current and shift its reversal potential to values more negative than the control. By silencing outward rectifier channel in its anoctamin 6 portion, we excluded a direct involvement of Cl- ions in modulation of IK and, by means of functional tests with its specific inhibitor spadin, we identified the TREK-1 channel as the presumable target of both drugs. As the activity of TREK-1 has a key role for the correct functioning of the alveolar epithelium, the identification of DCPIB and 9-AC molecules as its activators suggests their possible use to build new pharmacological tools for the modulation of this channel.
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Affiliation(s)
- Rita Canella
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Marta Martini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Carlotta Cavicchio
- Animal Science Department, Plants for Human Health Institute, NC State University, Kannapolis, North Carolina
| | - Franco Cervellati
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mascia Benedusi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,Animal Science Department, Plants for Human Health Institute, NC State University, Kannapolis, North Carolina
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19
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MacGilvary NJ, Kevorkian YL, Tan S. Potassium response and homeostasis in Mycobacterium tuberculosis modulates environmental adaptation and is important for host colonization. PLoS Pathog 2019; 15:e1007591. [PMID: 30716121 PMCID: PMC6375644 DOI: 10.1371/journal.ppat.1007591] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/14/2019] [Accepted: 01/22/2019] [Indexed: 11/19/2022] Open
Abstract
Successful host colonization by bacteria requires sensing and response to the local ionic milieu, and coordination of responses with the maintenance of ionic homeostasis in the face of changing conditions. We previously discovered that Mycobacterium tuberculosis (Mtb) responds synergistically to chloride (Cl-) and pH, as cues to the immune status of its host. This raised the intriguing concept of abundant ions as important environmental signals, and we have now uncovered potassium (K+) as an ion that can significantly impact colonization by Mtb. The bacterium has a unique transcriptional response to changes in environmental K+ levels, with both distinct and shared regulatory mechanisms controlling Mtb response to the ionic signals of K+, Cl-, and pH. We demonstrate that intraphagosomal K+ levels increase during macrophage phagosome maturation, and find using a novel fluorescent K+-responsive reporter Mtb strain that K+ is not limiting during macrophage infection. Disruption of Mtb K+ homeostasis by deletion of the Trk K+ uptake system results in dampening of the bacterial response to pH and Cl-, and attenuation in host colonization, both in primary murine bone marrow-derived macrophages and in vivo in a murine model of Mtb infection. Our study reveals how bacterial ionic homeostasis can impact environmental ionic responses, and highlights the important role that abundant ions can play during host colonization by Mtb.
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Affiliation(s)
- Nathan J. MacGilvary
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Yuzo L. Kevorkian
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts, United States of America
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts, United States of America
- * E-mail:
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20
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Webster MJ, Tarran R. Slippery When Wet: Airway Surface Liquid Homeostasis and Mucus Hydration. CURRENT TOPICS IN MEMBRANES 2018; 81:293-335. [PMID: 30243435 DOI: 10.1016/bs.ctm.2018.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The ability to regulate cell volume is crucial for normal physiology; equally the regulation of extracellular fluid homeostasis is of great importance. Alteration of normal extracellular fluid homeostasis contributes to the development of several diseases including cystic fibrosis. With regard to the airway surface liquid (ASL), which lies apically on top of airway epithelia, ion content, pH, mucin and protein abundance must be tightly regulated. Furthermore, airway epithelia must be able to switch from an absorptive to a secretory state as required. A heterogeneous population of airway epithelial cells regulate ASL solute and solvent composition, and directly secrete large mucin molecules, antimicrobials, proteases and soluble mediators into the airway lumen. This review focuses on how epithelial ion transport influences ASL hydration and ASL pH, with a specific focus on the roles of anion and cation channels and exchangers. The role of ions and pH in mucin expansion is also addressed. With regard to fluid volume regulation, we discuss the roles of nucleotides, adenosine and the short palate lung and nasal epithelial clone 1 (SPLUNC1) as soluble ASL mediators. Together, these mechanisms directly influence ciliary beating and in turn mucociliary clearance to maintain sterility and to detoxify the airways. Whilst all of these components are regulated in normal airways, defective ion transport and/or mucin secretion proves detrimental to lung homeostasis as such we address how defective ion and fluid transport, and a loss of homeostatic mechanisms, contributes to the development of pathophysiologies associated with cystic fibrosis.
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Affiliation(s)
- Megan J Webster
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Robert Tarran
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States; Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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Bartoszewski R, Matalon S, Collawn JF. Ion channels of the lung and their role in disease pathogenesis. Am J Physiol Lung Cell Mol Physiol 2017; 313:L859-L872. [PMID: 29025712 PMCID: PMC5792182 DOI: 10.1152/ajplung.00285.2017] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/03/2017] [Accepted: 10/03/2017] [Indexed: 12/16/2022] Open
Abstract
Maintenance of normal epithelial ion and water transport in the lungs includes providing a thin layer of surface liquid that coats the conducting airways. This airway surface liquid is critical for normal lung function in a number of ways but, perhaps most importantly, is required for normal mucociliary clearance and bacterial removal. Preservation of the appropriate level of hydration, pH, and viscosity for the airway surface liquid requires the proper regulation and function of a battery of different types of ion channels and transporters. Here we discuss how alterations in ion channel/transporter function often lead to lung pathologies.
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Affiliation(s)
- Rafal Bartoszewski
- Department of Biology and Pharmaceutical Botany, Medical University of Gdansk, Gdansk, Poland
| | - Sadis Matalon
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
- Gregory Fleming James Cystic Fibrosis Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - James F Collawn
- Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
- Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
- Gregory Fleming James Cystic Fibrosis Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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22
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Abbott GW. Chansporter complexes in cell signaling. FEBS Lett 2017; 591:2556-2576. [PMID: 28718502 DOI: 10.1002/1873-3468.12755] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/03/2017] [Accepted: 07/12/2017] [Indexed: 12/11/2022]
Abstract
Ion channels facilitate diffusion of ions across cell membranes for such diverse purposes as neuronal signaling, muscular contraction, and fluid homeostasis. Solute transporters often utilize ionic gradients to move aqueous solutes up their concentration gradient, also fulfilling a wide variety of tasks. Recently, an increasing number of ion channel-transporter ('chansporter') complexes have been discovered. Chansporter complex formation may overcome what could otherwise be considerable spatial barriers to rapid signal integration and feedback between channels and transporters, the ions and other substrates they transport, and environmental factors to which they must respond. Here, current knowledge in this field is summarized, covering both heterologous expression structure/function findings and potential mechanisms by which chansporter complexes fulfill contrasting roles in cell signaling in vivo.
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Affiliation(s)
- Geoffrey W Abbott
- Bioelectricity Laboratory, Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA
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Hover S, Foster B, Barr JN, Mankouri J. Viral dependence on cellular ion channels - an emerging anti-viral target? J Gen Virol 2017; 98:345-351. [PMID: 28113044 DOI: 10.1099/jgv.0.000712] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The broad range of cellular functions governed by ion channels represents an attractive target for viral manipulation. Indeed, modulation of host cell ion channel activity by viral proteins is being increasingly identified as an important virus-host interaction. Recent examples have demonstrated that virion entry, virus egress and the maintenance of a cellular environment conducive to virus persistence are, in part, dependent on virus manipulation of ion channel activity. Most excitingly, evidence has emerged that targeting ion channels pharmacologically can impede virus life cycles. Here, we discuss current examples of virus-ion channel interactions and the potential of targeting ion channel function as a new, pharmacologically safe and broad-ranging anti-viral therapeutic strategy.
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Affiliation(s)
- Samantha Hover
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Becky Foster
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - John N Barr
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Jamel Mankouri
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
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Schwingshackl A. The role of stretch-activated ion channels in acute respiratory distress syndrome: finally a new target? Am J Physiol Lung Cell Mol Physiol 2016; 311:L639-52. [PMID: 27521425 DOI: 10.1152/ajplung.00458.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 08/05/2016] [Indexed: 02/06/2023] Open
Abstract
Mechanical ventilation (MV) and oxygen therapy (hyperoxia; HO) comprise the cornerstones of life-saving interventions for patients with acute respiratory distress syndrome (ARDS). Unfortunately, the side effects of MV and HO include exacerbation of lung injury by barotrauma, volutrauma, and propagation of lung inflammation. Despite significant improvements in ventilator technologies and a heightened awareness of oxygen toxicity, besides low tidal volume ventilation few if any medical interventions have improved ARDS outcomes over the past two decades. We are lacking a comprehensive understanding of mechanotransduction processes in the healthy lung and know little about the interactions between simultaneously activated stretch-, HO-, and cytokine-induced signaling cascades in ARDS. Nevertheless, as we are unraveling these mechanisms we are gathering increasing evidence for the importance of stretch-activated ion channels (SACs) in the activation of lung-resident and inflammatory cells. In addition to the discovery of new SAC families in the lung, e.g., two-pore domain potassium channels, we are increasingly assigning mechanosensing properties to already known Na(+), Ca(2+), K(+), and Cl(-) channels. Better insights into the mechanotransduction mechanisms of SACs will improve our understanding of the pathways leading to ventilator-induced lung injury and lead to much needed novel therapeutic approaches against ARDS by specifically targeting SACs. This review 1) summarizes the reasons why the time has come to seriously consider SACs as new therapeutic targets against ARDS, 2) critically analyzes the physiological and experimental factors that currently limit our knowledge about SACs, and 3) outlines the most important questions future research studies need to address.
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TASK-1 Regulates Apoptosis and Proliferation in a Subset of Non-Small Cell Lung Cancers. PLoS One 2016; 11:e0157453. [PMID: 27294516 PMCID: PMC4905626 DOI: 10.1371/journal.pone.0157453] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/31/2016] [Indexed: 12/29/2022] Open
Abstract
Lung cancer is the leading cause of cancer deaths worldwide; survival times are poor despite therapy. The role of the two-pore domain K+ (K2P) channel TASK-1 (KCNK3) in lung cancer is at present unknown. We found that TASK-1 is expressed in non-small cell lung cancer (NSCLC) cell lines at variable levels. In a highly TASK-1 expressing NSCLC cell line, A549, a characteristic pH- and hypoxia-sensitive non-inactivating K+ current was measured, indicating the presence of functional TASK-1 channels. Inhibition of TASK-1 led to significant depolarization in these cells. Knockdown of TASK-1 by siRNA significantly enhanced apoptosis and reduced proliferation in A549 cells, but not in weakly TASK-1 expressing NCI-H358 cells. Na+-coupled nutrient transport across the cell membrane is functionally coupled to the efflux of K+ via K+ channels, thus TASK-1 may potentially influence Na+-coupled nutrient transport. In contrast to TASK-1, which was not differentially expressed in lung cancer vs. normal lung tissue, we found the Na+-coupled nutrient transporters, SLC5A3, SLC5A6, and SLC38A1, transporters for myo-inositol, biotin and glutamine, respectively, to be significantly overexpressed in lung adenocarcinomas. In summary, we show for the first time that the TASK-1 channel regulates apoptosis and proliferation in a subset of NSCLC.
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Bonnomet A, Luczka E, Coraux C, de Gabory L. Non-diluted seawater enhances nasal ciliary beat frequency and wound repair speed compared to diluted seawater and normal saline. Int Forum Allergy Rhinol 2016; 6:1062-1068. [PMID: 27101776 PMCID: PMC5074274 DOI: 10.1002/alr.21782] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/17/2016] [Accepted: 03/08/2016] [Indexed: 01/05/2023]
Abstract
Background The regulation of mucociliary clearance is a key part of the defense mechanisms developed by the airway epithelium. If a high aggregate quality of evidence shows the clinical effectiveness of nasal irrigation, there is a lack of studies showing the intrinsic role of the different irrigation solutions allowing such results. This study investigated the impact of solutions with different pH and ionic compositions, eg, normal saline, non‐diluted seawater and diluted seawater, on nasal mucosa functional parameters. Methods For this randomized, controlled, blinded, in vitro study, we used airway epithelial cells obtained from 13 nasal polyps explants to measure ciliary beat frequency (CBF) and epithelial wound repair speed (WRS) in response to 3 isotonic nasal irrigation solutions: (1) normal saline 0.9%; (2) non‐diluted seawater (Physiomer®); and (3) 30% diluted seawater (Stérimar). The results were compared to control (cell culture medium). Results Non‐diluted seawater enhanced the CBF and the WRS when compared to diluted seawater and to normal saline. When compared to the control, it significantly enhanced CBF and slightly, though nonsignificantly, improved the WRS. Interestingly, normal saline markedly reduced the number of epithelial cells and ciliated cells when compared to the control condition. Conclusion Our results suggest that the physicochemical features of the nasal wash solution is important because it determines the optimal conditions to enhance CBF and epithelial WRS thus preserving the respiratory mucosa in pathological conditions. Non‐diluted seawater obtains the best results on CBF and WRS vs normal saline showing a deleterious effect on epithelial cell function.
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Affiliation(s)
- Arnaud Bonnomet
- National Institute of Health and Medical Research (Institut National de la Santé et de la Recherche Médicale [INSERM]) Scientific Mixed Research unit UMRS-S 903, Federative Structure Health Research Champagne-Ardennes-Picardie (SFR CAP-Santé): FED 4231, University of Reims-Champagne-Ardenne, Reims, France.,Cellular and Tissular Imaging Platform (PICT), University of Reims-Champagne-Ardenne, Reims, France
| | - Emilie Luczka
- National Institute of Health and Medical Research (Institut National de la Santé et de la Recherche Médicale [INSERM]) Scientific Mixed Research unit UMRS-S 903, Federative Structure Health Research Champagne-Ardennes-Picardie (SFR CAP-Santé): FED 4231, University of Reims-Champagne-Ardenne, Reims, France
| | - Christelle Coraux
- National Institute of Health and Medical Research (Institut National de la Santé et de la Recherche Médicale [INSERM]) Scientific Mixed Research unit UMRS-S 903, Federative Structure Health Research Champagne-Ardennes-Picardie (SFR CAP-Santé): FED 4231, University of Reims-Champagne-Ardenne, Reims, France
| | - Ludovic de Gabory
- Ear Nose and Throat (ENT) Department, University Hospital of Bordeaux, Hôpital Pellegrin, Bordeaux, France.
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Investigating CFTR and KCa3.1 Protein/Protein Interactions. PLoS One 2016; 11:e0153665. [PMID: 27092946 PMCID: PMC4836752 DOI: 10.1371/journal.pone.0153665] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/02/2016] [Indexed: 12/11/2022] Open
Abstract
In epithelia, Cl- channels play a prominent role in fluid and electrolyte transport. Of particular importance is the cAMP-dependent cystic fibrosis transmembrane conductance regulator Cl- channel (CFTR) with mutations of the CFTR encoding gene causing cystic fibrosis. The bulk transepithelial transport of Cl- ions and electrolytes needs however to be coupled to an increase in K+ conductance in order to recycle K+ and maintain an electrical driving force for anion exit across the apical membrane. In several epithelia, this K+ efflux is ensured by K+ channels, including KCa3.1, which is expressed at both the apical and basolateral membranes. We show here for the first time that CFTR and KCa3.1 can physically interact. We first performed a two-hybrid screen to identify which KCa3.1 cytosolic domains might mediate an interaction with CFTR. Our results showed that both the N-terminal fragment M1-M40 of KCa3.1 and part of the KCa3.1 calmodulin binding domain (residues L345-A400) interact with the NBD2 segment (G1237-Y1420) and C- region of CFTR (residues T1387-L1480), respectively. An association of CFTR and F508del-CFTR with KCa3.1 was further confirmed in co-immunoprecipitation experiments demonstrating the formation of immunoprecipitable CFTR/KCa3.1 complexes in CFBE cells. Co-expression of KCa3.1 and CFTR in HEK cells did not impact CFTR expression at the cell surface, and KCa3.1 trafficking appeared independent of CFTR stimulation. Finally, evidence is presented through cross-correlation spectroscopy measurements that KCa3.1 and CFTR colocalize at the plasma membrane and that KCa3.1 channels tend to aggregate consequent to an enhanced interaction with CFTR channels at the plasma membrane following an increase in intracellular Ca2+ concentration. Altogether, these results suggest 1) that the physical interaction KCa3.1/CFTR can occur early during the biogenesis of both proteins and 2) that KCa3.1 and CFTR form a dynamic complex, the formation of which depends on internal Ca2+.
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Voltage-Gated K+ Channel, Kv3.3 Is Involved in Hemin-Induced K562 Differentiation. PLoS One 2016; 11:e0148633. [PMID: 26849432 PMCID: PMC4743930 DOI: 10.1371/journal.pone.0148633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 01/20/2016] [Indexed: 12/31/2022] Open
Abstract
Voltage-gated K+ (Kv) channels are well known to be involved in cell proliferation. However, even though cell proliferation is closely related to cell differentiation, the relationship between Kv channels and cell differentiation remains poorly investigated. This study demonstrates that Kv3.3 is involved in K562 cell erythroid differentiation. Down-regulation of Kv3.3 using siRNA-Kv3.3 increased hemin-induced K562 erythroid differentiation through decreased activation of signal molecules such as p38, cAMP response element-binding protein, and c-fos. Down-regulation of Kv3.3 also enhanced cell adhesion by increasing integrin β3 and this effect was amplified when the cells were cultured with fibronectin. The Kv channels, or at least Kv3.3, appear to be associated with cell differentiation; therefore, understanding the mechanisms of Kv channel regulation of cell differentiation would provide important information regarding vital cellular processes.
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29
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Bilodeau C, Bardou O, Maillé É, Berthiaume Y, Brochiero E. Deleterious impact of hyperglycemia on cystic fibrosis airway ion transport and epithelial repair. J Cyst Fibros 2016; 15:43-51. [DOI: 10.1016/j.jcf.2015.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 04/07/2015] [Accepted: 04/10/2015] [Indexed: 02/08/2023]
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30
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Villanueva S, Burgos J, López-Cayuqueo KI, Lai KMV, Valenzuela DM, Cid LP, Sepúlveda FV. Cleft Palate, Moderate Lung Developmental Retardation and Early Postnatal Lethality in Mice Deficient in the Kir7.1 Inwardly Rectifying K+ Channel. PLoS One 2015; 10:e0139284. [PMID: 26402555 PMCID: PMC4581704 DOI: 10.1371/journal.pone.0139284] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 09/09/2015] [Indexed: 12/15/2022] Open
Abstract
Kir7.1 is an inwardly rectifying K+ channel of the Kir superfamily encoded by the kcnj13 gene. Kir7.1 is present in epithelial tissues where it colocalizes with the Na+/K+-pump probably serving to recycle K+ taken up by the pump. Human mutations affecting Kir7.1 are associated with retinal degeneration diseases. We generated a mouse lacking Kir7.1 by ablation of the Kcnj13 gene. Homozygous mutant null mice die hours after birth and show cleft palate and moderate retardation in lung development. Kir7.1 is expressed in the epithelium covering the palatal processes at the time at which palate sealing takes place and our results suggest it might play an essential role in late palatogenesis. Our work also reveals a second unexpected role in the development and the physiology of the respiratory system, where Kir7.1 is expressed in epithelial cells all along the respiratory tree.
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Affiliation(s)
| | - Johanna Burgos
- Centro de Estudios Científicos (CECs), Valdivia, Chile
- Doctorado en Ciencias Veterinarias de la Universidad Austral de Chile, Valdivia, Chile
| | | | - Ka-Man Venus Lai
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, United States of America
| | - David M. Valenzuela
- Regeneron Pharmaceuticals, Inc., Tarrytown, New York, United States of America
| | - L. Pablo Cid
- Centro de Estudios Científicos (CECs), Valdivia, Chile
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Lin MT, Jian MY, Taylor MS, Cioffi DL, Yap FC, Liedtke W, Townsley MI. Functional coupling of TRPV4, IK, and SK channels contributes to Ca(2+)-dependent endothelial injury in rodent lung. Pulm Circ 2015; 5:279-90. [PMID: 26064452 DOI: 10.1086/680166] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 09/15/2014] [Indexed: 02/05/2023] Open
Abstract
Our previous work has shown that the increased lung endothelial permeability response to 14,15-epoxyeicosatrienoic acid (14,15-EET) in rat lung requires Ca(2+) entry via vanilloid type-4 transient receptor potential (TRPV4) channels. Recent studies suggest that activation of TRPV4 channels in systemic vascular endothelium prolongs agonist-induced hyperpolarization and amplifies Ca(2+) entry by activating Ca(2+)-activated K(+) (KCa) channels, resulting in vessel relaxation. Activation of endothelial KCa channels thus has potential to increase the electrochemical driving force for Ca(2+) influx via TRPV4 channels and to amplify permeability responses to TRPV4 activation in lung. To examine this hypothesis, we used Western blot analysis, electrophysiological recordings, and isolated-lung permeability measurements to document expression of TRPV4 and KCa channels and the potential for functional coupling. The results show that rat pulmonary microvascular endothelial cells express TRPV4 and 3 KCa channels of different conductances: large (BK), intermediate (IK), and small (SK3). However, TRPV4 channel activity modulates the IK and SK3, but not the BK, channel current density. Furthermore, the TRPV4-mediated permeability response to 14,15-EET in mouse lung is significantly attenuated by pharmacologic blockade of IK and SK3, but not BK, channels. Collectively, this functional coupling suggests that endothelial TRPV4 channels in rodent lung likely form signaling microdomains with IK and SK3 channels and that the integrated response dictates the extent of lung endothelial injury caused by 14,15-EET.
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Affiliation(s)
- Mike T Lin
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA ; These authors contributed equally to this work
| | - Ming-Yuan Jian
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA ; Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA ; Present address: Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, Alabama, USA. ; These authors contributed equally to this work
| | - Mark S Taylor
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
| | - Donna L Cioffi
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA ; Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Fui C Yap
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA
| | - Wolfgang Liedtke
- Departments of Medicine, Neurology and Neurobiology, Duke University, Durham, North Carolina, USA
| | - Mary I Townsley
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, USA ; Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA ; Department of Medicine, University of South Alabama, Mobile, Alabama, USA
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Renigunta V, Schlichthörl G, Daut J. Much more than a leak: structure and function of K₂p-channels. Pflugers Arch 2015; 467:867-94. [PMID: 25791628 DOI: 10.1007/s00424-015-1703-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 11/27/2022]
Abstract
Over the last decade, we have seen an enormous increase in the number of experimental studies on two-pore-domain potassium channels (K2P-channels). The collection of reviews and original articles compiled for this special issue of Pflügers Archiv aims to give an up-to-date summary of what is known about the physiology and pathophysiology of K2P-channels. This introductory overview briefly describes the structure of K2P-channels and their function in different organs. Its main aim is to provide some background information for the 19 reviews and original articles of this special issue of Pflügers Archiv. It is not intended to be a comprehensive review; instead, this introductory overview focuses on some unresolved questions and controversial issues, such as: Do K2P-channels display voltage-dependent gating? Do K2P-channels contribute to the generation of action potentials? What is the functional role of alternative translation initiation? Do K2P-channels have one or two or more gates? We come to the conclusion that we are just beginning to understand the extremely complex regulation of these fascinating channels, which are often inadequately described as 'leak channels'.
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Affiliation(s)
- Vijay Renigunta
- Institute of Physiology and Pathophysiology, Marburg University, 35037, Marburg, Germany
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Brune K, Frank J, Schwingshackl A, Finigan J, Sidhaye VK. Pulmonary epithelial barrier function: some new players and mechanisms. Am J Physiol Lung Cell Mol Physiol 2015; 308:L731-45. [PMID: 25637609 DOI: 10.1152/ajplung.00309.2014] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/27/2015] [Indexed: 12/20/2022] Open
Abstract
The pulmonary epithelium serves as a barrier to prevent access of the inspired luminal contents to the subepithelium. In addition, the epithelium dictates the initial responses of the lung to both infectious and noninfectious stimuli. One mechanism by which the epithelium does this is by coordinating transport of diffusible molecules across the epithelial barrier, both through the cell and between cells. In this review, we will discuss a few emerging paradigms of permeability changes through altered ion transport and paracellular regulation by which the epithelium gates its response to potentially detrimental luminal stimuli. This review is a summary of talks presented during a symposium in Experimental Biology geared toward novel and less recognized methods of epithelial barrier regulation. First, we will discuss mechanisms of dynamic regulation of cell-cell contacts in the context of repetitive exposure to inhaled infectious and noninfectious insults. In the second section, we will briefly discuss mechanisms of transcellular ion homeostasis specifically focused on the role of claudins and paracellular ion-channel regulation in chronic barrier dysfunction. In the next section, we will address transcellular ion transport and highlight the role of Trek-1 in epithelial responses to lung injury. In the final section, we will outline the role of epithelial growth receptor in barrier regulation in baseline, acute lung injury, and airway disease. We will then end with a summary of mechanisms of epithelial control as well as discuss emerging paradigms of the epithelium role in shifting between a structural element that maintains tight cell-cell adhesion to a cell that initiates and participates in immune responses.
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Affiliation(s)
- Kieran Brune
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland
| | - James Frank
- The Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco VA Medical Center, and NCIRE/Veterans Health Research Institute, San Francisco, California
| | - Andreas Schwingshackl
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee
| | - James Finigan
- Division of Oncology, Cancer Center, National Jewish Health, Denver, Colorado
| | - Venkataramana K Sidhaye
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland;
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Ionotropic and metabotropic proton-sensing receptors involved in airway inflammation in allergic asthma. Mediators Inflamm 2014; 2014:712962. [PMID: 25197168 PMCID: PMC4147257 DOI: 10.1155/2014/712962] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/10/2014] [Accepted: 07/24/2014] [Indexed: 12/19/2022] Open
Abstract
An acidic microenvironment has been shown to evoke a variety of airway responses, including cough, bronchoconstriction, airway hyperresponsiveness (AHR), infiltration of inflammatory cells in the lung, and stimulation of mucus hyperproduction. Except for the participation of transient receptor potential vanilloid-1 (TRPV1) and acid-sensing ion channels (ASICs) in severe acidic pH (of less than 6.0)-induced cough and bronchoconstriction through sensory neurons, the molecular mechanisms underlying extracellular acidic pH-induced actions in the airways have not been fully understood. Recent studies have revealed that ovarian cancer G protein-coupled receptor 1 (OGR1)-family G protein-coupled receptors, which sense pH of more than 6.0, are expressed in structural cells, such as airway smooth muscle cells and epithelial cells, and in inflammatory and immune cells, such as eosinophils and dendritic cells. They function in a variety of airway responses related to the pathophysiology of inflammatory diseases, including allergic asthma. In the present review, we discuss the roles of ionotropic TRPV1 and ASICs and metabotropic OGR1-family G protein-coupled receptors in the airway inflammation and AHR in asthma and respiratory diseases.
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Purkey MT, Li J, Mentch F, Grant SFA, Desrosiers M, Hakonarson H, Toskala E. Genetic variation in genes encoding airway epithelial potassium channels is associated with chronic rhinosinusitis in a pediatric population. PLoS One 2014; 9:e89329. [PMID: 24595210 PMCID: PMC3940609 DOI: 10.1371/journal.pone.0089329] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 01/18/2014] [Indexed: 11/19/2022] Open
Abstract
Background Apical potassium channels regulate ion transport in airway epithelial cells and influence air surface liquid (ASL) hydration and mucociliary clearance (MCC). We sought to identify whether genetic variation within genes encoding airway potassium channels is associated with chronic rhinosinusitis (CRS). Methods Single nucleotide polymorphism (SNP) genotypes for selected potassium channels were derived from data generated on the Illumnia HumanHap550 BeadChip or Illumina Human610-Quad BeadChip for 828 unrelated individuals diagnosed with CRS and 5,083 unrelated healthy controls from the Children's Hospital of Philadelphia (CHOP). Statistical analysis was performed with set-based tests using PLINK, and corrected for multiple testing. Results Set-based case control analysis revealed the gene KCNMA1 was associated with CRS in our Caucasian subset of the cohort (598 CRS cases and 3,489 controls; p = 0.022, based on 10,000 permutations). In addition there was borderline evidence that the gene KCNQ5 (p = 0.0704) was associated with the trait in our African American subset of the cohort (230 CRS cases and 1,594 controls). In addition to the top significant SNPs rs2917454 and rs6907229, imputation analysis uncovered additional genetic variants in KCNMA1 and in KCNQ5 that were associated with CRS. Conclusions We have implicated two airway epithelial potassium channels as novel susceptibility loci in contributing to the pathogenesis of CRS.
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Affiliation(s)
- Michael T. Purkey
- Department of Otorhinolaryngology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jin Li
- Center for Applied Genomics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Frank Mentch
- Center for Applied Genomics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Struan F. A. Grant
- Division of Human Genetics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Martin Desrosiers
- Department of Otolaryngology, Montreal General Hospital, McGill University, Montreal, Québec Canada
| | - Hakon Hakonarson
- Center for Applied Genomics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Division of Human Genetics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (HH); (ET)
| | - Elina Toskala
- Department of Otolaryngology, Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (HH); (ET)
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Girault A, Brochiero E. Evidence of K+ channel function in epithelial cell migration, proliferation, and repair. Am J Physiol Cell Physiol 2013; 306:C307-19. [PMID: 24196531 DOI: 10.1152/ajpcell.00226.2013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Efficient repair of epithelial tissue, which is frequently exposed to insults, is necessary to maintain its functional integrity. It is therefore necessary to better understand the biological and molecular determinants of tissue regeneration and to develop new strategies to promote epithelial repair. Interestingly, a growing body of evidence indicates that many members of the large and widely expressed family of K(+) channels are involved in regulation of cell migration and proliferation, key processes of epithelial repair. First, we briefly summarize the complex mechanisms, including cell migration, proliferation, and differentiation, engaged after epithelial injury. We then present evidence implicating K(+) channels in the regulation of these key repair processes. We also describe the mechanisms whereby K(+) channels may control epithelial repair processes. In particular, changes in membrane potential, K(+) concentration, cell volume, intracellular Ca(2+), and signaling pathways following modulation of K(+) channel activity, as well as physical interaction of K(+) channels with the cytoskeleton or integrins are presented. Finally, we discuss the challenges to efficient, specific, and safe targeting of K(+) channels for therapeutic applications to improve epithelial repair in vivo.
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Affiliation(s)
- Alban Girault
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada; and
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Shabbir W, Scherbaum-Hazemi P, Tzotzos S, Fischer B, Fischer H, Pietschmann H, Lucas R, Lemmens-Gruber R. Mechanism of action of novel lung edema therapeutic AP301 by activation of the epithelial sodium channel. Mol Pharmacol 2013; 84:899-910. [PMID: 24077967 DOI: 10.1124/mol.113.089409] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AP301 [Cyclo(CGQRETPEGAEAKPWYC)], a cyclic peptide comprising the human tumor necrosis factor lectin-like domain (TIP domain) sequence, is currently being developed as a treatment for lung edema and has been shown to reduce extravascular lung water and improve lung function in mouse, rat, and pig models. The current paradigm for liquid homeostasis in the adult mammalian lung is that passive apical uptake of sodium via the amiloride-sensitive epithelial Na⁺ channel (ENaC) and nonselective cyclic-nucleotide-gated cation channels creates the major driving force for reabsorption of water through the alveolar epithelium in addition to other ion channels such as potassium and chloride channels. AP301 can increase amiloride-sensitive current in A549 cells as well as in freshly isolated type II alveolar epithelial cells from different species. ENaC is expressed endogenously in all of these cell types. Consequently, this study was undertaken to determine whether ENaC is the specific target of AP301. The effect of AP301 in A549 cells as well as in human embryonic kidney cells and Chinese hamster ovary cells heterologously expressing human ENaC subunits (α, β, γ, and δ) was measured in patch clamp experiments. The congener TIP peptide AP318 [Cyclo(4-aminobutanoic acid-GQRETPEGAEAKPWYD)] activated ENaC by increasing single-channel open probability. AP301 increased current in proteolytically activated (cleaved) but not near-silent (uncleaved) ENaC in a reversible manner. αβγ- or δβγ-ENaC coexpression was required for maximal activity. No increase in current was observed after deglycosylation of extracellular domains of ENaC. Thus, our data suggest that the specific interaction of AP301 with both endogenously and heterologously expressed ENaC requires precedent binding to glycosylated extracellular loop(s).
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Affiliation(s)
- Waheed Shabbir
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (W.S., P.S.-H., R.L.-G.); APEPTICO Forschung und Entwicklung GmbH, Vienna, Austria (S.T., B.F., H.F., H.P.); and Division of Pulmonary Medicine, Department of Pharmacology and Toxicology, Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia (R.L.)
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Richter K, Kiefer KP, Grzesik BA, Clauss WG, Fronius M. Hydrostatic pressure activates ATP-sensitive K+ channels in lung epithelium by ATP release through pannexin and connexin hemichannels. FASEB J 2013; 28:45-55. [PMID: 24048216 DOI: 10.1096/fj.13-229252] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lungs of air-breathing vertebrates are constantly exposed to mechanical forces and therefore are suitable for investigation of mechanotransduction processes in nonexcitable cells and tissues. Freshly dissected Xenopus laevis lungs were used for transepithelial short-circuit current (ISC) recordings and were exposed to increased hydrostatic pressure (HP; 5 cm fluid column, modified Ussing chamber). I(SC) values obtained under HP (I(5cm)) were normalized to values before HP (I(0cm)) application (I(5cm)/I(0cm)). Under control conditions, HP decreased I(SC) (I(5cm)/I(0cm)=0.84; n=68; P<0.0001). This effect was reversible and repeatable ≥30 times. Preincubation with ATP-sensitive K(+) channel (K(ATP)) inhibitors (HMR1098 and glibenclamide) prevented the decrease in I(SC) (I(5cm)/I(0cm): HMR1098=1.19, P<0.0001; glibenclamide=1.11, P<0.0001). Similar effects were observed with hemichannel inhibitors (I(5cm)/I(0cm): meclofenamic acid=1.09, P<0.0001; probenecid=1.0, P<0.0001). The HP effect was accompanied by release of ATP (P<0.05), determined by luciferin-luciferase luminescence in perfusion solution from the luminal side of an Ussing chamber. ATP release was abrogated by both meclofenamic acid and probenecid. RT-PCR experiments revealed the expression of pannexin and connexin hemichannels and KATP subunit transcripts in X. laevis lung. These data show an activation of KATP in pulmonary epithelial cells in response to HP that is induced by ATP release through mechanosensitive pannexin and connexin hemichannels. These findings represent a novel mechanism of mechanotransduction in nonexcitable cells.
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Affiliation(s)
- Katrin Richter
- 2Institute of Animal Physiology, Justus Liebig University, Giessen, Heinrich Buff Ring 26, D-35392 Giessen, Germany.
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Abstract
Ion channels perform a variety of cellular functions in lung epithelia. Oxidant- and antioxidant-mediated mechanisms (that is, redox regulation) of ion channels are areas of intense research. Significant progress has been made in our understanding of redox regulation of ion channels since the last Experimental Biology report in 2003. Advancements include: 1) identification of nonphagocytic NADPH oxidases as sources of regulated reactive species (RS) production in epithelia, 2) an understanding that excessive treatment with antioxidants can result in greater oxidative stress, and 3) characterization of novel RS signaling pathways that converge upon ion channel regulation. These advancements, as discussed at the 2013 Experimental Biology Meeting in Boston, MA, impact our understanding of oxidative stress in the lung, and, in particular, illustrate that the redox state has profound effects on ion channel and cellular function.
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Dagenais A, Tessier MC, Tatur S, Brochiero E, Grygorczyk R, Berthiaume Y. Hypotonic shock modulates Na(+) current via a Cl(-) and Ca(2+)/calmodulin dependent mechanism in alveolar epithelial cells. PLoS One 2013; 8:e74565. [PMID: 24019969 PMCID: PMC3760838 DOI: 10.1371/journal.pone.0074565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 08/05/2013] [Indexed: 12/02/2022] Open
Abstract
Alveolar epithelial cells are involved in Na+ absorption via the epithelial Na+ channel (ENaC), an important process for maintaining an appropriate volume of liquid lining the respiratory epithelium and for lung oedema clearance. Here, we investigated how a 20% hypotonic shock modulates the ionic current in these cells. Polarized alveolar epithelial cells isolated from rat lungs were cultured on permeant filters and their electrophysiological properties recorded. A 20% bilateral hypotonic shock induced an immediate, but transient 52% rise in total transepithelial current and a 67% increase in the amiloride-sensitive current mediated by ENaC. Amiloride pre-treatment decreased the current rise after hypotonic shock, showing that ENaC current is involved in this response. Since Cl- transport is modulated by hypotonic shock, its contribution to the basal and hypotonic-induced transepithelial current was also assessed. Apical NPPB, a broad Cl- channel inhibitor and basolateral DIOA a potassium chloride co-transporter (KCC) inhibitor reduced the total and ENaC currents, showing that transcellular Cl- transport plays a major role in that process. During hypotonic shock, a basolateral Cl- influx, partly inhibited by NPPB is essential for the hypotonic-induced current rise. Hypotonic shock promoted apical ATP secretion and increased intracellular Ca2+. While apyrase, an ATP scavenger, did not inhibit the hypotonic shock current response, W7 a calmodulin antagonist completely prevented the hypotonic current rise. These results indicate that a basolateral Cl- influx as well as Ca2+/calmodulin, but not ATP, are involved in the acute transepithelial current rise elicited by hypotonic shock.
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Affiliation(s)
- André Dagenais
- Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada
- Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
- * E-mail:
| | | | - Sabina Tatur
- Centre de Recherche du CHUM (CRCHUM), Centre Hospitalier de l’Université de Montréal, Montreal, Quebec, Canada
| | - Emmanuelle Brochiero
- Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
- Centre de Recherche du CHUM (CRCHUM), Centre Hospitalier de l’Université de Montréal, Montreal, Quebec, Canada
| | - Ryszard Grygorczyk
- Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
- Centre de Recherche du CHUM (CRCHUM), Centre Hospitalier de l’Université de Montréal, Montreal, Quebec, Canada
| | - Yves Berthiaume
- Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada
- Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
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Guillot L, Nathan N, Tabary O, Thouvenin G, Le Rouzic P, Corvol H, Amselem S, Clement A. Alveolar epithelial cells: master regulators of lung homeostasis. Int J Biochem Cell Biol 2013; 45:2568-73. [PMID: 23988571 DOI: 10.1016/j.biocel.2013.08.009] [Citation(s) in RCA: 173] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 07/12/2013] [Accepted: 08/16/2013] [Indexed: 01/04/2023]
Abstract
The lung interfaces with the environment across a continuous epithelium composed of various cell types along the proximal and distal airways. At the alveolar structure level, the epithelium, which is composed of type I and type II alveolar epithelial cells, represents a critical component of lung homeostasis. Indeed, its fundamental role is to provide an extensive surface for gas exchange. Additional functions that act to preserve the capacity for such unique gas transfer have been progressively identified. The alveolar epithelium represents a physical barrier that protects from environmental insults by segregating inhaled foreign agents and regulating water and ions transport, thereby contributing to the maintenance of alveolar surface fluid balance. The homeostatic role of alveolar epithelium relies on the regulated/controlled production of the pulmonary surfactant, which is not only a key determinant of alveolar mechanical stability but also a complex structure that participates in the cross-talk between local cells and the lung immune and inflammatory response. In regard to these critical functions, a major point is the maintenance of alveolar surface integrity, which relies on the renewal capacity of type II alveolar epithelial cells, and the contribution of progenitor populations within the lung.
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Affiliation(s)
- Loïc Guillot
- Inserm, UMR S-938, F-75012 Paris, France; UPMC Univ Paris 06, F-75005 Paris, France
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Kroigaard C, Dalsgaard T, Nielsen G, Laursen BE, Pilegaard H, Köhler R, Simonsen U. Activation of endothelial and epithelial K(Ca) 2.3 calcium-activated potassium channels by NS309 relaxes human small pulmonary arteries and bronchioles. Br J Pharmacol 2013; 167:37-47. [PMID: 22506557 DOI: 10.1111/j.1476-5381.2012.01986.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Small (K(Ca) 2) and intermediate (K(Ca) 3.1) conductance calcium-activated potassium channels (K(Ca) ) may contribute to both epithelium- and endothelium-dependent relaxations, but this has not been established in human pulmonary arteries and bronchioles. Therefore, we investigated the expression of K(Ca) 2.3 and K(Ca) 3.1 channels, and hypothesized that activation of these channels would produce relaxation of human bronchioles and pulmonary arteries. EXPERIMENTAL APPROACH Channel expression and functional studies were conducted in human isolated small pulmonary arteries and bronchioles. K(Ca) 2 and K(Ca) 3.1 currents were examined in human small airways epithelial (HSAEpi) cells by whole-cell patch clamp techniques. RESULTS While K(Ca) 2.3 expression was similar, K(Ca) 3.1 protein was more highly expressed in pulmonary arteries than bronchioles. Immunoreactive K(Ca) 2.3 and K(Ca) 3.1 proteins were found in both endothelium and epithelium. K(Ca) currents were present in HSAEpi cells and sensitive to the K(Ca) 2.3 blocker UCL1684 and the K(Ca) 3.1 blocker TRAM-34. In pulmonary arteries contracted by U46619 and in bronchioles contracted by histamine, the K(Ca) 2.3/ K(Ca) 3.1 activator, NS309, induced concentration-dependent relaxations. NS309 was equally potent in relaxing pulmonary arteries, but less potent in bronchioles, than salbutamol. NS309 relaxations were blocked by the K(Ca) 2 channel blocker apamin, while the K(Ca) 3.1 channel blocker, charybdotoxin failed to reduce relaxation to NS309 (0.01-1 µM). CONCLUSIONS AND IMPLICATIONS K(Ca) 2.3 and K(Ca) 3.1 channels are expressed in the endothelium of human pulmonary arteries and epithelium of bronchioles. K(Ca) 2.3 channels contributed to endo- and epithelium-dependent relaxations suggesting that these channels are potential targets for treatment of pulmonary hypertension and chronic obstructive pulmonary disease.
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Affiliation(s)
- Christel Kroigaard
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Faculty of Health Sciences, Aarhus University, Aarhus C, Denmark
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Hollenhorst MI, Lips KS, Wolff M, Wess J, Gerbig S, Takats Z, Kummer W, Fronius M. Luminal cholinergic signalling in airway lining fluid: a novel mechanism for activating chloride secretion via Ca²⁺-dependent Cl⁻ and K⁺ channels. Br J Pharmacol 2012; 166:1388-402. [PMID: 22300281 DOI: 10.1111/j.1476-5381.2012.01883.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE Recent studies detected the expression of proteins involved in cholinergic metabolism in airway epithelial cells, although the function of this non-neuronal cholinergic system is not known in detail. Thus, this study focused on the effect of luminal ACh as a regulator of transepithelial ion transport in epithelial cells. EXPERIMENTAL APPROACH RT-PCR experiments were performed using mouse tracheal epithelial cells for ChAT and organic cation transporter (OCT) transcripts. Components of tracheal airway lining fluid were analysed with desorption electrospray ionization (DESI) MS. Effects of nicotine on mouse tracheal epithelial ion transport were examined with Ussing-chamber experiments. KEY RESULTS Transcripts encoding ChAT and OCT1-3 were detected in mouse tracheal epithelial cells. The DESI experiments identified ACh in the airway lining fluid. Luminal ACh induced an immediate, dose-dependent increase in the transepithelial ion current (EC₅₀: 23.3 µM), characterized by a transient peak and sustained plateau current. This response was not affected by the Na⁺-channel inhibitor amiloride. The Cl⁻-channel inhibitor niflumic acid or the K⁺-channel blocker Ba²⁺ attenuated the ACh effect. The calcium ionophore A23187 mimicked the ACh effect. Luminal nicotine or muscarine increased the ion current. Experiments with receptor gene-deficient animals revealed the participation of muscarinic receptor subtypes M₁ and M₃. CONCLUSIONS AND IMPLICATIONS The presence of luminal ACh and activation of transepithelial ion currents by luminal ACh receptors identifies a novel non-neuronal cholinergic pathway in the airway lining fluid. This pathway could represent a novel drug target in the airways.
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Affiliation(s)
- Monika I Hollenhorst
- Institute of Animal Physiology, Justus-Liebig-University Giessen, Giessen, Germany
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Fronius M, Clauss WG, Althaus M. Why Do We have to Move Fluid to be Able to Breathe? Front Physiol 2012; 3:146. [PMID: 22661953 PMCID: PMC3357553 DOI: 10.3389/fphys.2012.00146] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 05/01/2012] [Indexed: 12/11/2022] Open
Abstract
The ability to breathe air represents a fundamental step in vertebrate evolution that was accompanied by several anatomical and physiological adaptations. The morphology of the air-blood barrier is highly conserved within air-breathing vertebrates. It is formed by three different plies, which are represented by the alveolar epithelium, the basal lamina, and the endothelial layer. Besides these conserved morphological elements, another common feature of vertebrate lungs is that they contain a certain amount of fluid that covers the alveolar epithelium. The volume and composition of the alveolar fluid is regulated by transepithelial ion transport mechanisms expressed in alveolar epithelial cells. These transport mechanisms have been reviewed extensively. Therefore, the present review focuses on the properties and functional significance of the alveolar fluid. How does the fluid enter the alveoli? What is the fate of the fluid in the alveoli? What is the function of the alveolar fluid in the lungs? The review highlights the importance of the alveolar fluid, its volume and its composition. Maintenance of the fluid volume and composition within certain limits is critical to facilitate gas exchange. We propose that the alveolar fluid is an essential element of the air-blood barrier. Therefore, it is appropriate to refer to this barrier as being formed by four plies, namely (1) the thin fluid layer covering the apical membrane of the epithelial cells, (2) the epithelial cell layer, (3) the basal membrane, and (4) the endothelial cells.
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Affiliation(s)
- Martin Fronius
- Molecular Cell Physiology, Institute of Animal Physiology, Justus-Liebig-University Giessen Giessen, Germany
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Toczyłowska-Mamińska R, Dołowy K. Ion transporting proteins of human bronchial epithelium. J Cell Biochem 2012; 113:426-32. [PMID: 21975871 DOI: 10.1002/jcb.23393] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The electrolyte transport system across human airway epithelium followed by water movement is essential for the normal mucociliary clearance that allows the maintenance of the aseptic condition of the respiratory tract. The function of epithelial cells is to control and regulate ionic composition and volume of fluids in the airways. Various types of proteins taking part in assuring effective ions and water transport in apical and basolateral membranes of the airway epithelium have been found (e.g., CFTR, ENaC, CaCC, ORCC, potassium channels, NaKATPase, aquaporins). The paper reviews the current state of the art in the field of ion channels, transporters, and other signaling proteins identified in the human bronchial epithelium.
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Affiliation(s)
- Renata Toczyłowska-Mamińska
- Department of Biophysics, Warsaw University of Life Sciences (SGGW), 159 Nowoursynowska St, 0-776 Warsaw, Poland.
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Hamilton KL, Devor DC. Basolateral membrane K+ channels in renal epithelial cells. Am J Physiol Renal Physiol 2012; 302:F1069-81. [PMID: 22338089 DOI: 10.1152/ajprenal.00646.2011] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The major function of epithelial tissues is to maintain proper ion, solute, and water homeostasis. The tubule of the renal nephron has an amazingly simple structure, lined by epithelial cells, yet the segments (i.e., proximal tubule vs. collecting duct) of the nephron have unique transport functions. The functional differences are because epithelial cells are polarized and thus possess different patterns (distributions) of membrane transport proteins in the apical and basolateral membranes of the cell. K(+) channels play critical roles in normal physiology. Over 90 different genes for K(+) channels have been identified in the human genome. Epithelial K(+) channels can be located within either or both the apical and basolateral membranes of the cell. One of the primary functions of basolateral K(+) channels is to recycle K(+) across the basolateral membrane for proper function of the Na(+)-K(+)-ATPase, among other functions. Mutations of these channels can cause significant disease. The focus of this review is to provide an overview of the basolateral K(+) channels of the nephron, providing potential physiological functions and pathophysiology of these channels, where appropriate. We have taken a "K(+) channel gene family" approach in presenting the representative basolateral K(+) channels of the nephron. The basolateral K(+) channels of the renal epithelia are represented by members of the KCNK, KCNJ, KCNQ, KCNE, and SLO gene families.
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Affiliation(s)
- Kirk L Hamilton
- Department of Physiology, Otago School of Medical Sciences, University of Otago, PO Box 913, Dunedin, New Zealand.
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Tagne JB, Gupta S, Gower AC, Shen SS, Varma S, Lakshminarayanan M, Cao Y, Spira A, Volkert TL, Ramirez MI. Genome-wide analyses of Nkx2-1 binding to transcriptional target genes uncover novel regulatory patterns conserved in lung development and tumors. PLoS One 2012; 7:e29907. [PMID: 22242187 PMCID: PMC3252372 DOI: 10.1371/journal.pone.0029907] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 12/07/2011] [Indexed: 01/10/2023] Open
Abstract
The homeodomain transcription factor Nkx2-1 is essential for normal lung development and homeostasis. In lung tumors, it is considered a lineage survival oncogene and prognostic factor depending on its expression levels. The target genes directly bound by Nkx2-1, that could be the primary effectors of its functions in the different cellular contexts where it is expressed, are mostly unknown. In embryonic day 11.5 (E11.5) mouse lung, epithelial cells expressing Nkx2-1 are predominantly expanding, and in E19.5 prenatal lungs, Nkx2-1-expressing cells are predominantly differentiating in preparation for birth. To evaluate Nkx2-1 regulated networks in these two cell contexts, we analyzed genome-wide binding of Nkx2-1 to DNA regulatory regions by chromatin immunoprecipitation followed by tiling array analysis, and intersected these data to expression data sets. We further determined expression patterns of Nkx2-1 developmental target genes in human lung tumors and correlated their expression levels to that of endogenous NKX2-1. In these studies we uncovered differential Nkx2-1 regulated networks in early and late lung development, and a direct function of Nkx2-1 in regulation of the cell cycle by controlling the expression of proliferation-related genes. New targets, validated in Nkx2-1 shRNA transduced cell lines, include E2f3, Cyclin B1, Cyclin B2, and c-Met. Expression levels of Nkx2-1 direct target genes identified in mouse development significantly correlate or anti-correlate to the levels of endogenous NKX2-1 in a dosage-dependent manner in multiple human lung tumor expression data sets, supporting alternative roles for Nkx2-1 as a transcriptional activator or repressor, and direct regulator of cell cycle progression in development and tumors.
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Affiliation(s)
- Jean-Bosco Tagne
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Sumeet Gupta
- Center for Microarray Technology, Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Adam C. Gower
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
| | - Steven S. Shen
- Clinical and Translational Science Institute (CTSI), Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Saaket Varma
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | | | - Yuxia Cao
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Avrum Spira
- Bioinformatics Program, Boston University, Boston, Massachusetts, United States of America
- Clinical and Translational Science Institute (CTSI), Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Thomas L. Volkert
- Center for Microarray Technology, Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Maria I. Ramirez
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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Schmid D, Stolzlechner M, Sorgner A, Bentele C, Assinger A, Chiba P, Moeslinger T. An abundant, truncated human sulfonylurea receptor 1 splice variant has prodiabetic properties and impairs sulfonylurea action. Cell Mol Life Sci 2012; 69:129-48. [PMID: 21671119 PMCID: PMC11114697 DOI: 10.1007/s00018-011-0739-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 05/20/2011] [Accepted: 05/23/2011] [Indexed: 12/20/2022]
Abstract
An alternatively spliced form of human sulfonylurea receptor (SUR) 1 mRNA lacking exon 2 (SUR1Δ2) has been identified. The omission of exon 2 caused a frame shift and an immediate stop codon in exon 3 leading to translation of a 5.6-kDa peptide that comprises the N-terminal extracellular domain and the first transmembrane helix of SUR1. Based on a weak first splice acceptor site in the human SUR1 gene (ABCC8), RT-PCR revealed a concurrent expression of SUR1Δ2 and SUR1. The SUR1Δ2/(SUR1 + SUR1Δ2) mRNA ratio differed between tissues, and was lowest in pancreas (46%), highest in heart (88%) and negatively correlated with alternative splice factor/splicing factor 2 (ASF/SF2) expression. In COS-7 cells triple transfected with SUR1Δ2/SUR1/Kir6.2, the SUR1Δ2 peptide co-immunoprecipitated with Kir6.2, thereby displacing two of four SUR1 subunits on the cell surface. The ATP sensitivity of these hybrid ATP-sensitive potassium channels (K(ATP)) channels was reduced by about sixfold, as shown with single-channel recordings. RINm5f rat insulinoma cells, which genuinely express SUR1 but not SUR1Δ2, exhibited a strongly increased K(ATP) channel current upon transfection with SUR1Δ2. This led to inhibition of glucose-induced depolarization, calcium flux, insulin release and glibenclamide action. A non-mutagenic SNP on nucleotide position 333 (Pro69Pro) added another exonic splicing enhancer sequence detected by ASF/SF2, reduced relative abundance of SUR1Δ2 and slightly protected from non-insulin dependent diabetes in homozygotic individuals. Thus, SUR1Δ2 represents an endogenous K(ATP)-channel modulator with prodiabetic properties in islet cells. Its predominance in heart may explain why high-affinity sulfonylurea receptors are not found in human cardiac tissue.
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MESH Headings
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- Alternative Splicing/physiology
- Animals
- COS Cells
- Calcium/metabolism
- Chlorocebus aethiops
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Exons/physiology
- Glyburide/pharmacology
- Humans
- Hypoglycemic Agents/pharmacology
- Insulin/metabolism
- Islets of Langerhans/metabolism
- KATP Channels/drug effects
- KATP Channels/metabolism
- Myocardium/metabolism
- Organ Specificity/genetics
- Pancreas/metabolism
- Polymorphism, Single Nucleotide
- Potassium Channels, Inwardly Rectifying/genetics
- Potassium Channels, Inwardly Rectifying/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Receptors, Drug/genetics
- Receptors, Drug/metabolism
- Species Specificity
- Sulfonylurea Receptors
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Affiliation(s)
- Diethart Schmid
- Institute of Physiology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
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Maillé E, Trinh NTN, Privé A, Bilodeau C, Bissonnette É, Grandvaux N, Brochiero E. Regulation of normal and cystic fibrosis airway epithelial repair processes by TNF-α after injury. Am J Physiol Lung Cell Mol Physiol 2011; 301:L945-55. [DOI: 10.1152/ajplung.00149.2011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chronic infection and inflammation have been associated with progressive airway epithelial damage in patients with cystic fibrosis (CF). However, the effect of inflammatory products on the repair capacity of respiratory epithelia is unclear. Our objective was to study the regulation of repair mechanisms by tumor necrosis factor-α (TNF-α), a major component of inflammation in CF, in a model of mechanical wounding, in two bronchial cell lines, non-CF NuLi and CF CuFi. We observed that TNF-α enhanced the NuLi and CuFi repair rates. Chronic exposure (24–48 h) to TNF-α augmented this stimulation as well as the migration rate during repair. The cellular mechanisms involved in this stimulation were then evaluated. First, we discerned that TNF-α induced metalloproteinase-9 release, epidermal growth factor (EGF) shedding, and subsequent EGF receptor transactivation. Second, TNF-α-induced stimulation of the NuLi and CuFi wound-closure rates was prevented by GM6001 (metalloproteinase inhibitor), EGF antibody (to titrate secreted EGF), and EGF receptor tyrosine kinase inhibitors. Furthermore, we recently reported a relationship between the EGF response and K+channel function, both controlling bronchial repair. We now show that TNF-α enhances KvLQT1 and KATPcurrents, while their inhibition abolishes TNF-α-induced repair stimulation. These results indicate that the effect of TNF-α is mediated, at least in part, through EGF receptor transactivation and K+channel stimulation. In contrast, cell proliferation during repair was slowed by TNF-α, suggesting that TNF-α could exert contrasting actions on repair mechanisms of CF airway epithelia. Finally, the stimulatory effect of TNF-α on airway wound repair was confirmed on primary airway epithelial cells, from non-CF and CF patients.
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Affiliation(s)
- Emilie Maillé
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM)—Hôtel-Dieu, Montréal
- Département de médecine and
| | - Nguyen Thu Ngan Trinh
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM)—Hôtel-Dieu, Montréal
- Département de médecine and
| | - Anik Privé
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM)—Hôtel-Dieu, Montréal
| | - Claudia Bilodeau
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM)—Hôtel-Dieu, Montréal
| | - Élyse Bissonnette
- Institut Universitaire de cardiologie et de pneumologie de Québec, Département de médecine, Université Laval, Québec, Québec, Canada
| | - Nathalie Grandvaux
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM)—Hôtel-Dieu, Montréal
- Département de Biochimie, Université de Montréal, Montréal; and
| | - Emmanuelle Brochiero
- Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM)—Hôtel-Dieu, Montréal
- Département de médecine and
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50
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Ion transport by pulmonary epithelia. J Biomed Biotechnol 2011; 2011:174306. [PMID: 22131798 PMCID: PMC3205707 DOI: 10.1155/2011/174306] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 08/16/2011] [Indexed: 12/13/2022] Open
Abstract
The lung surface of air-breathing vertebrates is formed by a continuous epithelium that is covered by a fluid layer. In the airways, this epithelium is largely pseudostratified consisting of diverse cell types such as ciliated cells, goblet cells, and undifferentiated basal cells, whereas the alveolar epithelium consists of alveolar type I and alveolar type II cells. Regulation and maintenance of the volume and viscosity of the fluid layer covering the epithelium is one of the most important functions of the epithelial barrier that forms the outer surface area of the lungs. Therefore, the epithelial cells are equipped with a wide variety of ion transport proteins, among which Na+, Cl−, and K+ channels have been identified to play a role in the regulation of the fluid layer. Malfunctions of pulmonary epithelial ion transport processes and, thus, impairment of the liquid balance in our lungs is associated with severe diseases, such as cystic fibrosis and pulmonary oedema. Due to the important role of pulmonary epithelial ion transport processes for proper lung function, the present paper summarizes the recent findings about composition, function, and ion transport properties of the airway epithelium as well as of the alveolar epithelium.
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