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Emin MT, Lee MJ, Bhattacharya J, Hough RF. Mitochondria of lung venular capillaries mediate lung-liver cross talk in pneumonia. Am J Physiol Lung Cell Mol Physiol 2023; 325:L277-L287. [PMID: 37431588 PMCID: PMC10625830 DOI: 10.1152/ajplung.00209.2022] [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: 06/29/2022] [Revised: 07/02/2023] [Accepted: 07/03/2023] [Indexed: 07/12/2023] Open
Abstract
Failure of the lung's endothelial barrier underlies lung injury, which causes the high mortality acute respiratory distress syndrome (ARDS). Multiple organ failure predisposes to the mortality, but mechanisms are poorly understood. Here, we show that mitochondrial uncoupling protein 2 (UCP2), a component of the mitochondrial inner membrane, plays a role in the barrier failure. Subsequent lung-liver cross talk mediated by neutrophil activation causes liver congestion. We intranasally instilled lipopolysaccharide (LPS). Then, we viewed the lung endothelium by real-time confocal imaging of the isolated, blood-perfused mouse lung. LPS caused alveolar-capillary transfer of reactive oxygen species and mitochondrial depolarization in lung venular capillaries. The mitochondrial depolarization was inhibited by transfection of alveolar Catalase and vascular knockdown of UCP2. LPS instillation caused lung injury as indicated by increases in bronchoalveolar lavage (BAL) protein content and extravascular lung water. LPS or Pseudomonas aeruginosa instillation also caused liver congestion, quantified by liver hemoglobin and plasma aspartate aminotransferase (AST) increases. Genetic inhibition of vascular UCP2 prevented both lung injury and liver congestion. Antibody-mediated neutrophil depletion blocked the liver responses, but not lung injury. Knockdown of lung vascular UCP2 mitigated P. aeruginosa-induced mortality. Together, these data suggest a mechanism in which bacterial pneumonia induces oxidative signaling to lung venular capillaries, known sites of inflammatory signaling in the lung microvasculature, depolarizing venular mitochondria. Successive activation of neutrophils induces liver congestion. We conclude that oxidant-induced UCP2 expression in lung venular capillaries causes a mechanistic sequence leading to liver congestion and mortality. Lung vascular UCP2 may present a therapeutic target in ARDS.NEW & NOTEWORTHY We report that mitochondrial injury in lung venular capillaries underlies barrier failure in pneumonia, and venular capillary uncoupling protein 2 (UCP2) causes neutrophil-mediated liver congestion. Using in situ imaging, we found that epithelial-endothelial transfer of H2O2 activates UCP2, depolarizing mitochondria in venular capillaries. The conceptual advance from our findings is that mitochondrial depolarization in lung capillaries mediates liver cross talk through circulating neutrophils. Pharmacologic blockade of UCP2 could be a therapeutic strategy for lung injury.
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Affiliation(s)
- Memet T Emin
- Department of Pediatrics, Pediatric Critical Care and Hospital Medicine, Columbia University Irving Medical Center, New York, New York, United States
| | - Michael J Lee
- Department of Pathology and Cell Biology, Columbia University, New York, New York, United States
| | - Jahar Bhattacharya
- Lung Biology Laboratory, Pulmonary Division, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, United States
| | - Rebecca F Hough
- Department of Pediatrics, Pediatric Critical Care and Hospital Medicine, Columbia University Irving Medical Center, New York, New York, United States
- Lung Biology Laboratory, Pulmonary Division, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, United States
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2
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Cusack R, Bos LD, Povoa P, Martin-Loeches I. Endothelial dysfunction triggers acute respiratory distress syndrome in patients with sepsis: a narrative review. Front Med (Lausanne) 2023; 10:1203827. [PMID: 37332755 PMCID: PMC10272540 DOI: 10.3389/fmed.2023.1203827] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/16/2023] [Indexed: 06/20/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a severe organ failure occurring mainly in critically ill patients as a result of different types of insults such as sepsis, trauma or aspiration. Sepsis is the main cause of ARDS, and it contributes to a high mortality and resources consumption both in hospital setting and in the community. ARDS develops mainly an acute respiratory failure with severe and often refractory hypoxemia. ARDS also has long term implications and sequelae. Endothelial damage plays an important role in the pathogenesis of ARDS. Understanding the mechanisms of ARDS presents opportunities for novel diagnostic and therapeutic targets. Biochemical signals can be used in concert to identify and classify patients into ARDS phenotypes allowing earlier effective treatment with personalised therapies. This is a narrative review where we aimed to flesh out the pathogenetic mechanisms and heterogeneity of ARDS. We examine the links between endothelium damage and its contribution to organ failure. We have also investigated future strategies for treatment with a special emphasis in endothelial damage.
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Affiliation(s)
- Rachael Cusack
- Department of Intensive Care, St. James’s Hospital, Dublin, Ireland
- School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Lieuwe D. Bos
- Intensive Care, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Pedro Povoa
- NOVA Medical School, CHRC, New University of Lisbon, Lisbon, Portugal
- Center for Clinical Epidemiology and Research Unit of Clinical Epidemiology, OUH Odense University Hospital, Odense, Denmark
- Department of Intensive Care, Hospital de São Francisco Xavier, CHLO, Lisbon, Portugal
| | - Ignacio Martin-Loeches
- Department of Intensive Care, St. James’s Hospital, Dublin, Ireland
- School of Medicine, Trinity College Dublin, Dublin, Ireland
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3
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Sanches Santos Rizzo Zuttion M, Moore SKL, Chen P, Beppu AK, Hook JL. New Insights into the Alveolar Epithelium as a Driver of Acute Respiratory Distress Syndrome. Biomolecules 2022; 12:biom12091273. [PMID: 36139112 PMCID: PMC9496395 DOI: 10.3390/biom12091273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/02/2022] [Accepted: 09/08/2022] [Indexed: 11/29/2022] Open
Abstract
The alveolar epithelium serves as a barrier between the body and the external environment. To maintain efficient gas exchange, the alveolar epithelium has evolved to withstand and rapidly respond to an assortment of inhaled, injury-inducing stimuli. However, alveolar damage can lead to loss of alveolar fluid barrier function and exuberant, non-resolving inflammation that manifests clinically as acute respiratory distress syndrome (ARDS). This review discusses recent discoveries related to mechanisms of alveolar homeostasis, injury, repair, and regeneration, with a contemporary emphasis on virus-induced lung injury. In addition, we address new insights into how the alveolar epithelium coordinates injury-induced lung inflammation and review maladaptive lung responses to alveolar damage that drive ARDS and pathologic lung remodeling.
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Affiliation(s)
- Marilia Sanches Santos Rizzo Zuttion
- Women’s Guild Lung Institute, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Sarah Kathryn Littlehale Moore
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Peter Chen
- Women’s Guild Lung Institute, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Andrew Kota Beppu
- Women’s Guild Lung Institute, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Jaime Lynn Hook
- Lung Imaging Laboratory, Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Global Health and Emerging Pathogens Institute, Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Correspondence:
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4
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Zhan B, Shen J. Mitochondria and their potential role in acute lung injury (Review). Exp Ther Med 2022; 24:479. [PMID: 35761815 PMCID: PMC9214601 DOI: 10.3892/etm.2022.11406] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/16/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Biao Zhan
- Center of Emergency and Critical Medicine, Jinshan Hospital of Fudan University, Shanghai 201508, P.R. China
| | - Jie Shen
- Center of Emergency and Critical Medicine, Jinshan Hospital of Fudan University, Shanghai 201508, P.R. China
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5
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Tan YB, Pastukh VM, Gorodnya OM, Mulekar MS, Simmons JD, Machuca TN, Beaver TM, Wilson GL, Gillespie MN. Enhanced Mitochondrial DNA Repair Resuscitates Transplantable Lungs Donated After Circulatory Death. J Surg Res 2019; 245:273-280. [PMID: 31421373 DOI: 10.1016/j.jss.2019.07.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 06/18/2019] [Accepted: 07/18/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND Transplantation of lungs procured after donation after circulatory death (DCD) is challenging because postmortem metabolic degradation may engender susceptibility to ischemia-reperfusion (IR) injury. Because oxidative mitochondrial DNA (mtDNA) damage has been linked to endothelial barrier disruption in other models of IR injury, here we used a fusion protein construct targeting the DNA repair 8-oxoguanine DNA glycosylase-1 (OGG1) to mitochondria (mtOGG1) to determine if enhanced repair of mtDNA damage attenuates endothelial barrier dysfunction after IR injury in a rat model of lung procurement after DCD. MATERIALS AND METHODS Lungs excised from donor rats 1 h after cardiac death were cold stored for 2 h after which they were perfused ex vivo in the absence and presence of mt-OGG1 or an inactive mt-OGG1 mutant. Lung endothelial barrier function and mtDNA integrity were determined during and at the end of perfusion, respectively. RESULTS AND CONCLUSIONS Mitochondria-targeted OGG1 attenuated indices of lung endothelial dysfunction incurred after a 1h post-mortem period. Oxidative lung tissue mtDNA damage as well as accumulation of proinflammatory mtDNA fragments in lung perfusate, but not nuclear DNA fragments, also were reduced by mitochondria-targeted OGG1. A repair-deficient mt-OGG1 mutant failed to protect lungs from the adverse effects of DCD procurement. CONCLUSIONS These findings suggest that endothelial barrier dysfunction in lungs procured after DCD is driven by mtDNA damage and point to strategies to enhance mtDNA repair in concert with EVLP as a means of alleviating DCD-related lung IR injury.
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Affiliation(s)
- Yong B Tan
- Department of Surgery, College of Medicine, University of South Alabama, Mobile, Alabama
| | - Viktor M Pastukh
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, Alabama
| | - Olena M Gorodnya
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, Alabama
| | - Madhuri S Mulekar
- Department of Mathematics and Statistics, College of Medicine, University of South Alabama, Mobile, Alabama
| | - Jon D Simmons
- Department of Surgery, College of Medicine, University of South Alabama, Mobile, Alabama; Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, Alabama
| | - Tiago N Machuca
- Department of Surgery, College of Medicine, University of Florida, Gainesville, Florida
| | - Thomas M Beaver
- Department of Surgery, College of Medicine, University of Florida, Gainesville, Florida
| | | | - Mark N Gillespie
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, Alabama.
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6
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Hough RF, Islam MN, Gusarova GA, Jin G, Das S, Bhattacharya J. Endothelial mitochondria determine rapid barrier failure in chemical lung injury. JCI Insight 2019; 4:124329. [PMID: 30728333 DOI: 10.1172/jci.insight.124329] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/20/2018] [Indexed: 12/14/2022] Open
Abstract
Acid aspiration, which can result from several etiologies, including postoperative complications, leads to direct contact of concentrated hydrochloric acid (HCl) with the alveolar epithelium. As a result, rapid endothelial activation induces alveolar inflammation, leading to life-threatening pulmonary edema. Because mechanisms underlying the rapid endothelial activation are not understood, here we determined responses in real time through optical imaging of alveoli of live mouse lungs. By alveolar micropuncture, we microinfused concentrated HCl in the alveolar lumen. As expected, acid contact with the epithelium caused rapid, but transient, apical injury. However, there was no concomitant membrane injury to the endothelium. Nevertheless, H2O2-mediated epithelial-endothelial paracrine signaling induced endothelial barrier failure, as detected by microvascular dextran leakage and lung water quantification. Remarkably, endothelial mitochondria regulated the barrier failure by activating uncoupling protein 2 (UCP2), thereby inducing transient mitochondrial depolarization that led to cofilin-induced actin depolymerization. Knockdown, or endothelium-targeted deletion of UCP2 expression, blocked these responses, including pulmonary edema. To our knowledge, these findings are the first to mechanistically implicate endothelial mitochondria in acid-induced barrier deterioration and pulmonary edema. We suggest endothelial UCP2 may be a therapeutic target for acid-induced acute lung injury.
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Affiliation(s)
- Rebecca F Hough
- Lung Biology Lab, Department of Medicine, and.,Department of Pediatrics, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, USA
| | | | | | | | - Shonit Das
- Lung Biology Lab, Department of Medicine, and
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7
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Yin J, Lv L, Zhai P, Long T, Zhou Q, Pan H, Botwe G, Wang L, Wang Q, Tan L, Kuebler WM. Connexin 40 regulates lung endothelial permeability in acute lung injury via the ROCK1-MYPT1- MLC20 pathway. Am J Physiol Lung Cell Mol Physiol 2019; 316:L35-L44. [PMID: 30234377 DOI: 10.1152/ajplung.00012.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Increased pulmonary vascular permeability is a hallmark of acute lung injury (ALI). Connexin 40 (Cx40) is a gap junctional protein abundantly present in the lung microvascular endothelium. Yet, the role of Cx40 in the regulation of lung vascular permeability and its underlying mechanisms are unclear. Here, we tested the hypothesis that Cx40 participates in regulation of lung endothelial permeability via a mechanism involving a Rho-associated protein kinase (ROCK) dependent regulation of myosin light chain (MLC). In murine models of intratracheal acid- or LPS-induced lung injury, genetic deficiency of Cx40 attenuated key features of ALI including vascular barrier failure. In human pulmonary microvascular endothelial cells (PMVECs), thrombin-induced loss of transendothelial electrical resistance was attenuated by a Cx40-inhibiting mimetic peptide (40GAP27), Cx40-specific shRNA, or ROCK inhibitor Y27632. In isolated perfused mouse lungs, platelet-activating factor-induced lung weight gain was abrogated by gap junction blocker carbenoxolone, 40GAP27, Y27632, or genetic deficiency of Cx40. Phosphorylation of MLC20 increased drastically in both LPS-treated PMVECs and HCl-treated mouse lungs. Expression of ROCK1 was increased in both LPS-treated PMVECs and HCl-treated mouse lungs, and paralleled by phosphorylation of MLC20. Coimmunoprecipitation experiments revealed protein-protein interaction between ROCK1 and Cx40. LPS-induced upregulation of ROCK1 and phosphorylation of MLC20 were blocked by knockdown of Cx40. LPS caused phosphorylation of myosin phosphatase targeting subunit 1, which could be abrogated by Y27632 or Cx40-shRNA. Our findings reveal a role of Cx40 in regulation of ROCK1 and MLC20 that contributes critically to lung vascular barrier failure in ALI.
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Affiliation(s)
- Jun Yin
- Department of Thoracic Surgery, Zhongshan Hospital of Fudan University , Shanghai , China
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Lu Lv
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Peng Zhai
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Tao Long
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Qiang Zhou
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Huiwen Pan
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Godwin Botwe
- Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Liming Wang
- Department of Chemotherapy, Cancer Institute, Affiliated People's Hospital of Jiangsu University , Zhenjiang, Jiangsu , China
| | - Qun Wang
- Department of Thoracic Surgery, Zhongshan Hospital of Fudan University , Shanghai , China
| | - Lijie Tan
- Department of Thoracic Surgery, Zhongshan Hospital of Fudan University , Shanghai , China
| | - Wolfgang M Kuebler
- Department of Physiology and Center for Cardiovascular Research, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health , Berlin , Germany
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8
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Gramatté J, Pietzsch J, Bergmann R, Richter T. Causative treatment of acid aspiration induced acute lung injury - Recent trends from animal experiments and critical perspective. Clin Hemorheol Microcirc 2018; 69:187-195. [PMID: 29630538 DOI: 10.3233/ch-189113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Aspiration of low-pH gastric fluid leads to an initial pneumonitis, which may become complicated by subsequent pneumonia or acute respiratory distress syndrome. Current treatment is at best supportive, but there is growing experimental evidence on the significant contribution of both neutrophils and platelets in the development of this inflammatory pulmonary reaction, a condition that can be attenuated by several medicinal products. This review aims to summarize novel findings in experimental models on pathomechanisms after an acid-aspiration event. Given the clinical relevance, specific emphasis is put on deduced potential experimental therapeutic approaches, which make use of the characteristic alteration of microcirculation in the injured lung.
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Affiliation(s)
- Johannes Gramatté
- Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany
| | - Jens Pietzsch
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.,Department of Chemistry and Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Ralf Bergmann
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Torsten Richter
- Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany
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9
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Abstract
Crosstalk signaling between the closely juxtaposed epithelial and endothelial membranes of pulmonary alveoli establishes the lung's immune defense against inhaled and blood-borne pathogens. The crosstalk can occur in a forward direction, as from alveolus to capillary, or in a reverse direction, as from capillary to alveolus. The crosstalk direction likely depends on the site at which pathogens first initiate signaling. Thus, forward crosstalk may occur when inhaled pathogens encounter the alveolar epithelium, while reverse crosstalk may result from interactions of blood-borne pathogens with the endothelium. Here, we review the factors that regulate these two directions of signaling.
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Affiliation(s)
- Rebecca F Hough
- 1 Lung Biology Lab, Columbia University College of Physicians & Surgeons, New York, NY, USA.,2 Department of Pediatrics, Columbia University College of Physicians & Surgeons, New York, NY, USA
| | - Sunita Bhattacharya
- 1 Lung Biology Lab, Columbia University College of Physicians & Surgeons, New York, NY, USA.,2 Department of Pediatrics, Columbia University College of Physicians & Surgeons, New York, NY, USA
| | - Jahar Bhattacharya
- 1 Lung Biology Lab, Columbia University College of Physicians & Surgeons, New York, NY, USA.,3 Department of Medicine, Columbia University College of Physicians & Surgeons, New York, NY, USA
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10
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Huertas A, Guignabert C, Barberà JA, Bärtsch P, Bhattacharya J, Bhattacharya S, Bonsignore MR, Dewachter L, Dinh-Xuan AT, Dorfmüller P, Gladwin MT, Humbert M, Kotsimbos T, Vassilakopoulos T, Sanchez O, Savale L, Testa U, Wilkins MR. Pulmonary vascular endothelium: the orchestra conductor in respiratory diseases. Eur Respir J 2018; 51:13993003.00745-2017. [DOI: 10.1183/13993003.00745-2017] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 02/03/2018] [Indexed: 12/15/2022]
Abstract
The European Respiratory Society (ERS) Research Seminar entitled “Pulmonary vascular endothelium: orchestra conductor in respiratory diseases - highlights from basic research to therapy” brought together international experts in dysfunctional pulmonary endothelium, from basic science to translational medicine, to discuss several important aspects in acute and chronic lung diseases. This review will briefly sum up the different topics of discussion from this meeting which was held in Paris, France on October 27–28, 2016. It is important to consider that this paper does not address all aspects of endothelial dysfunction but focuses on specific themes such as: 1) the complex role of the pulmonary endothelium in orchestrating the host response in both health and disease (acute lung injury, chronic obstructive pulmonary disease, high-altitude pulmonary oedema and pulmonary hypertension); and 2) the potential value of dysfunctional pulmonary endothelium as a target for innovative therapies.
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11
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Hook JL, Islam MN, Parker D, Prince AS, Bhattacharya S, Bhattacharya J. Disruption of staphylococcal aggregation protects against lethal lung injury. J Clin Invest 2018; 128:1074-1086. [PMID: 29431734 DOI: 10.1172/jci95823] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 01/04/2018] [Indexed: 01/23/2023] Open
Abstract
Infection by Staphylococcus aureus strain USA300 causes tissue injury, multiorgan failure, and high mortality. However, the mechanisms by which the bacteria adhere to, then stabilize on, mucosal surfaces before causing injury remain unclear. We addressed these issues through the first real-time determinations of USA300-alveolar interactions in live lungs. We found that within minutes, inhaled USA300 established stable, self-associated microaggregates in niches at curved, but not at flat, regions of the alveolar wall. The microaggregates released α-hemolysin toxin, causing localized alveolar injury, as indicated by epithelial dye loss, mitochondrial depolarization, and cytosolic Ca2+ increase. Spread of cytosolic Ca2+ through intercellular gap junctions to adjoining, uninfected alveoli caused pulmonary edema. Systemic pretreatment with vancomycin, a USA300-cidal antibiotic, failed to protect mice infected with inhaled WT USA300. However, vancomycin pretreatment markedly abrogated mortality in mice infected with mutant USA300 that lacked the aggregation-promoting factor PhnD. We interpret USA300-induced mortality as having resulted from rapid bacterial aggregation in alveolar niches. These findings indicate, for the first time to our knowledge, that alveolar microanatomy is critical in promoting the aggregation and, hence, in causing USA300-induced alveolar injury. We propose that in addition to antibiotics, strategies for bacterial disaggregation may constitute novel therapy against USA300-induced lung injury.
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Affiliation(s)
- Jaime L Hook
- Lung Biology Laboratory, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | - Mohammad N Islam
- Lung Biology Laboratory, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine
| | | | | | - Sunita Bhattacharya
- Lung Biology Laboratory, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine.,Department of Pediatrics, and
| | - Jahar Bhattacharya
- Lung Biology Laboratory, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine.,Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University Medical Center, New York, New York, USA
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12
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Cong X, Hubmayr RD, Li C, Zhao X. Plasma membrane wounding and repair in pulmonary diseases. Am J Physiol Lung Cell Mol Physiol 2017; 312:L371-L391. [PMID: 28062486 PMCID: PMC5374305 DOI: 10.1152/ajplung.00486.2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/05/2017] [Accepted: 01/05/2017] [Indexed: 12/12/2022] Open
Abstract
Various pathophysiological conditions such as surfactant dysfunction, mechanical ventilation, inflammation, pathogen products, environmental exposures, and gastric acid aspiration stress lung cells, and the compromise of plasma membranes occurs as a result. The mechanisms necessary for cells to repair plasma membrane defects have been extensively investigated in the last two decades, and some of these key repair mechanisms are also shown to occur following lung cell injury. Because it was theorized that lung wounding and repair are involved in the pathogenesis of acute respiratory distress syndrome (ARDS) and idiopathic pulmonary fibrosis (IPF), in this review, we summarized the experimental evidence of lung cell injury in these two devastating syndromes and discuss relevant genetic, physical, and biological injury mechanisms, as well as mechanisms used by lung cells for cell survival and membrane repair. Finally, we discuss relevant signaling pathways that may be activated by chronic or repeated lung cell injury as an extension of our cell injury and repair focus in this review. We hope that a holistic view of injurious stimuli relevant for ARDS and IPF could lead to updated experimental models. In addition, parallel discussion of membrane repair mechanisms in lung cells and injury-activated signaling pathways would encourage research to bridge gaps in current knowledge. Indeed, deep understanding of lung cell wounding and repair, and discovery of relevant repair moieties for lung cells, should inspire the development of new therapies that are likely preventive and broadly effective for targeting injurious pulmonary diseases.
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Affiliation(s)
- Xiaofei Cong
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia
| | - Rolf D Hubmayr
- Emerius, Thoracic Diseases Research Unit, Mayo Clinic, Rochester, Minnesota; and
| | - Changgong Li
- Department of Pediatrics, University of Southern California, Los Angeles, California
| | - Xiaoli Zhao
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia;
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13
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Aman J, Weijers EM, van Nieuw Amerongen GP, Malik AB, van Hinsbergh VWM. Using cultured endothelial cells to study endothelial barrier dysfunction: Challenges and opportunities. Am J Physiol Lung Cell Mol Physiol 2016; 311:L453-66. [PMID: 27343194 DOI: 10.1152/ajplung.00393.2015] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 06/20/2016] [Indexed: 12/24/2022] Open
Abstract
Despite considerable progress in the understanding of endothelial barrier regulation and the identification of approaches that have the potential to improve endothelial barrier function, no drug- or stem cell-based therapy is presently available to reverse the widespread vascular leak that is observed in acute respiratory distress syndrome (ARDS) and sepsis. The translational gap suggests a need to develop experimental approaches and tools that better mimic the complex environment of the microcirculation in which the vascular leak develops. Recent studies have identified several elements of this microenvironment. Among these are composition and stiffness of the extracellular matrix, fluid shear stress, interaction of endothelial cells (ECs) with pericytes, oxygen tension, and the combination of toxic and mechanic injurious stimuli. Development of novel cell culture techniques that integrate these elements would allow in-depth analysis of EC biology that closely approaches the (patho)physiological conditions in situ. In parallel, techniques to isolate organ-specific ECs, to define EC heterogeneity in its full complexity, and to culture patient-derived ECs from inducible pluripotent stem cells or endothelial progenitor cells are likely to advance the understanding of ARDS and lead to development of therapeutics. This review 1) summarizes the advantages and pitfalls of EC cultures to study vascular leak in ARDS, 2) provides an overview of elements of the microvascular environment that can directly affect endothelial barrier function, and 3) discusses alternative methods to bridge the gap between basic research and clinical application with the intent of improving the translational value of present EC culture approaches.
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Affiliation(s)
- Jurjan Aman
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands; Department of Pulmonary Diseases, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands;
| | - Ester M Weijers
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Geerten P van Nieuw Amerongen
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Asrar B Malik
- Department of Pharmacology, University of Illinois College of Medicine, Chicago, Illinois
| | - Victor W M van Hinsbergh
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
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Bhattacharya J, Westphalen K. Macrophage-epithelial interactions in pulmonary alveoli. Semin Immunopathol 2016; 38:461-9. [PMID: 27170185 DOI: 10.1007/s00281-016-0569-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/29/2016] [Indexed: 12/20/2022]
Abstract
Alveolar macrophages have been investigated for years by approaches involving macrophage extraction from the lung by bronchoalveolar lavage, or by cell removal from lung tissue. Since extracted macrophages are studied outside their natural milieu, there is little understanding of the extent to which alveolar macrophages interact with the epithelium, or with one another to generate the lung's innate immune response to pathogen challenge. Here, we review new evidence of macrophage-epithelial interactions in the lung, and we address the emerging understanding that the alveolar epithelium plays an important role in orchestrating the macrophage-driven immune response.
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Affiliation(s)
- Jahar Bhattacharya
- Departments of Medicine and Physiology and Cellular Biophysics, Columbia University, New York, NY, USA.
| | - Kristin Westphalen
- Department of Anesthesiology, Ludwig Maximilians University, Munich, Germany.,Comprehensive Pneumology Center (CPC), German Center for Lung Research (DZL), Munich, Germany
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Reduced pulmonary blood flow in regions of injury 2 hours after acid aspiration in rats. BMC Anesthesiol 2015; 15:36. [PMID: 25805960 PMCID: PMC4372178 DOI: 10.1186/s12871-015-0013-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 02/24/2015] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Aspiration-induced lung injury can decrease gas exchange and increase mortality. Acute lung injury following acid aspiration is characterized by elevated pulmonary blood flow (PBF) in damaged lung areas in the early inflammation stage. Knowledge of PBF patterns after acid aspiration is important for targeting intravenous treatments. We examined PBF in an experimental model at a later stage (2 hours after injury). METHODS Anesthetized Wistar-Unilever rats (n = 5) underwent unilateral endobronchial instillation of hydrochloric acid. The PBF distribution was compared between injured and uninjured sides and with that of untreated control animals (n = 6). Changes in lung density after injury were measured using computed tomography (CT). Regional PBF distribution was determined quantitatively in vivo 2 hours after acid instillation by measuring the concentration of [(68)Ga]-radiolabeled microspheres using positron emission tomography. RESULTS CT scans revealed increased lung density in areas of acid aspiration. Lung injury was accompanied by impaired gas exchange. Acid aspiration decreased the arterial pressure of oxygen from 157 mmHg [139;165] to 74 mmHg [67;86] at 20 minutes and tended toward restoration to 109 mmHg [69;114] at 110 minutes (P < 0.001). The PBF ratio of the middle region of the injured versus uninjured lungs of the aspiration group (0.86 [0.7;0.9], median [25%;75%]) was significantly lower than the PBF ratio in the left versus right lung of the control group (1.02 [1.0;1.05]; P = 0.016). CONCLUSIONS The PBF pattern 2 hours after aspiration-induced lung injury showed a redistribution of PBF away from injured regions that was likely responsible for the partial recovery from hypoxemia over time. Treatments given intravenously 2 hours after acid-induced lung injury may not preferentially reach the injured lung regions, contrary to what occurs during the first hour of inflammation. Please see related article: http://dx.doi.org/10.1186/s12871-015-0014-z.
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Mehta D, Ravindran K, Kuebler WM. Novel regulators of endothelial barrier function. Am J Physiol Lung Cell Mol Physiol 2014; 307:L924-35. [PMID: 25381026 PMCID: PMC4269690 DOI: 10.1152/ajplung.00318.2014] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 11/05/2014] [Indexed: 12/15/2022] Open
Abstract
Endothelial barrier function is an essential and tightly regulated process that ensures proper compartmentalization of the vascular and interstitial space, while allowing for the diffusive exchange of small molecules and the controlled trafficking of macromolecules and immune cells. Failure to control endothelial barrier integrity results in excessive leakage of fluid and proteins from the vasculature that can rapidly become fatal in scenarios such as sepsis or the acute respiratory distress syndrome. Here, we highlight recent advances in our understanding on the regulation of endothelial permeability, with a specific focus on the endothelial glycocalyx and endothelial scaffolds, regulatory intracellular signaling cascades, as well as triggers and mediators that either disrupt or enhance endothelial barrier integrity, and provide our perspective as to areas of seeming controversy and knowledge gaps, respectively.
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Affiliation(s)
- Dolly Mehta
- Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois;
| | - Krishnan Ravindran
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada
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Herold S, Gabrielli NM, Vadász I. Novel concepts of acute lung injury and alveolar-capillary barrier dysfunction. Am J Physiol Lung Cell Mol Physiol 2013; 305:L665-81. [PMID: 24039257 DOI: 10.1152/ajplung.00232.2013] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In this review we summarize recent major advances in our understanding on the molecular mechanisms, mediators, and biomarkers of acute lung injury (ALI) and alveolar-capillary barrier dysfunction, highlighting the role of immune cells, inflammatory and noninflammatory signaling events, mechanical noxae, and the affected cellular and molecular entities and functions. Furthermore, we address novel aspects of resolution and repair of ALI, as well as putative candidates for treatment of ALI, including pharmacological and cellular therapeutic means.
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Affiliation(s)
- Susanne Herold
- Dept. of Internal Medicine, Justus Liebig Univ., Universities of Giessen and Marburg Lung Center, Klinikstrasse 33, 35392 Giessen, Germany.
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