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Dushianthan A, Martin D, Mouncey P, Shahid T, Lampro L, Johnson AF, Goss V, Cazley A, Herbert W, Jones W, Lamond M, Neyroud F, Salmon K, Lentaigne J, Minnion M, Panchal M, Koster G, Moyses H, Postle AD, Feelisch M, Grocott MPW. Oxidative stress, redox status and surfactant metabolism in mechanically ventilated patients receiving different approaches to oxygen therapy (MecROX): An observational study protocol for mechanistic evaluation. NIHR OPEN RESEARCH 2024; 4:23. [PMID: 39145107 PMCID: PMC11320187 DOI: 10.3310/nihropenres.13567.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 07/02/2024] [Indexed: 08/16/2024]
Abstract
Background MecROX is a mechanistic sub-study of the UK-ROX trial which was designed to evaluate the clinical and cost-effectiveness of a conservative approach to oxygen therapy for invasively ventilated adults in intensive care. This is based on the scientific rationale that excess oxygen is harmful. Epithelial cell damage with alveolar surfactant deficiency is characteristic of hyperoxic acute lung injury. Additionally, hyperoxaemia (excess blood oxygen levels) may exacerbate whole-body oxidative stress leading to cell death, autophagy, mitochondrial dysfunction, bioenergetic failure and multi-organ failure resulting in poor clinical outcomes. However, there is a lack of in-vivo human models evaluating the mechanisms that underpin oxygen-induced organ damage in mechanically ventilated patients. Aim The aim of the MecROX mechanistic sub-study is to assess lung surfactant composition and global systemic redox status to provide a mechanistic and complementary scientific rationale to the UK-ROX trial findings. The objectives are to quantify in-vivo surfactant composition, synthesis, and metabolism with markers of oxidative stress and systemic redox disequilibrium (as evidenced by alterations in the 'reactive species interactome') to differentiate between groups of conservative and usual oxygen targets. Methods and design After randomisation into the UK-ROX trial, 100 adult participants (50 in the conservative and 50 in usual care group) will be recruited at two trial sites. Blood and endotracheal samples will be taken at 0, 48 and 72 hours following an infusion of 3 mg/kg methyl-D 9-choline chloride. This is a non-radioactive, stable isotope of choline (vitamin), which has been extensively used to study surfactant phospholipid kinetics in humans. This study will mechanistically evaluate the in-vivo surfactant synthesis and breakdown (by hydrolysis and oxidation), oxidative stress and redox disequilibrium from sequential plasma and bronchial samples using an array of analytical platforms. We will compare conservative and usual oxygenation groups according to the amount of oxygen administered. Trial registration: ISRCTNISRCTN61929838, 27/03/2023 https://doi.org/10.1186/ISRCTN61929838.
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Affiliation(s)
- Ahilanandan Dushianthan
- General Intensive Care Unit, University Hospital Southampton, Southamnpton, Hampshire, SO16 6YD, UK
- NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
- Faculty of Medicine, University of Southampton, Southampton, England, SO16 6YD, UK
| | - Daniel Martin
- Peninsula Medical School, University of Plymouth, Plymouth, England, PL6 8BT, UK
- Department of Intensive Care, University Hospital Plymouth, Plymouth, Devon, PL6 8DH, UK
| | - Paul Mouncey
- Intensive Care National Audit and Research Centre, London, England, UK
| | - Tasnin Shahid
- Intensive Care National Audit and Research Centre, London, England, UK
| | - Lamprini Lampro
- Intensive Care National Audit and Research Centre, London, England, UK
| | | | - Victoria Goss
- Clinical Trials Unit (CTU), University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Angelica Cazley
- Clinical Trials Unit (CTU), University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - William Herbert
- Clinical Trials Unit (CTU), University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - William Jones
- Patient and Public Involvement Team, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Mark Lamond
- Patient and Public Involvement Team, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Florence Neyroud
- General Intensive Care Unit, University Hospital Southampton, Southamnpton, Hampshire, SO16 6YD, UK
| | - Karen Salmon
- General Intensive Care Unit, University Hospital Southampton, Southamnpton, Hampshire, SO16 6YD, UK
| | - Julian Lentaigne
- Department of Intensive Care, University Hospital Plymouth, Plymouth, Devon, PL6 8DH, UK
| | - Magdalena Minnion
- NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Madhuri Panchal
- NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Grielof Koster
- NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Helen Moyses
- NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Anthony D Postle
- NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
- Faculty of Medicine, University of Southampton, Southampton, England, SO16 6YD, UK
| | - Martin Feelisch
- NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
- Faculty of Medicine, University of Southampton, Southampton, England, SO16 6YD, UK
| | - Michael P W Grocott
- General Intensive Care Unit, University Hospital Southampton, Southamnpton, Hampshire, SO16 6YD, UK
- NIHR Biomedical Research Centre, University Hospital Southampton, Southampton, Hampshire, SO16 6YD, UK
- Faculty of Medicine, University of Southampton, Southampton, England, SO16 6YD, UK
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2
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Liu JY, George IC, Hussain S, Sayes CM. High-throughput screening of respiratory hazards: Exploring lung surfactant inhibition with 20 benchmark chemicals. Toxicology 2024; 504:153785. [PMID: 38518839 DOI: 10.1016/j.tox.2024.153785] [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: 02/09/2024] [Revised: 03/05/2024] [Accepted: 03/19/2024] [Indexed: 03/24/2024]
Abstract
As environmental air quality worsens and respiratory health injuries and diseases increase, it is essential to enhance our ability to develop better methods to identify potential hazards. One promising approach in emerging toxicology involves the utilization of lung surfactant as a model that addresses the limitations of conventional in vitro toxicology methods by incorporating the biophysical aspect of inhalation. This study employed a constrained drop surfactometer to assess 20 chemicals for potential surfactant inhibition. Of these, eight were identified as inhibiting lung surfactant function: 1-aminoethanol, bovine serum albumin, maleic anhydride, propylene glycol, sodium glycocholate, sodium taurocholate, sodium taurodeoxycholate, and Triton X-100. These results are consistent with previously reported chemical-induced acute lung dysfunction in vivo. The study provides information on each chemical's minimum and maximum surface tension conditions and corresponding relative area and contact angle values. Isotherms and box plots are reported for selected chemicals across doses, and vector plots are used to summarize and compare the results concisely. This lung surfactant bioassay is a promising non-animal model for hazard identification, with broader implications for developing predictive modeling and decision-making tools.
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Affiliation(s)
- James Y Liu
- Department of Environmental Science, Baylor University, Waco, TX 76798-7266, USA
| | - Ian C George
- 711th Human Performance Wing, Air Force Research Laboratory, Dayton, OH, USA
| | - Saber Hussain
- 711th Human Performance Wing, Air Force Research Laboratory, Dayton, OH, USA
| | - Christie M Sayes
- Department of Environmental Science, Baylor University, Waco, TX 76798-7266, USA.
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3
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Dushianthan A, Bracegirdle L, Cusack R, Cumpstey AF, Postle AD, Grocott MPW. Alveolar Hyperoxia and Exacerbation of Lung Injury in Critically Ill SARS-CoV-2 Pneumonia. Med Sci (Basel) 2023; 11:70. [PMID: 37987325 PMCID: PMC10660857 DOI: 10.3390/medsci11040070] [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: 09/26/2023] [Revised: 10/17/2023] [Accepted: 10/30/2023] [Indexed: 11/22/2023] Open
Abstract
Acute hypoxic respiratory failure (AHRF) is a prominent feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) critical illness. The severity of gas exchange impairment correlates with worse prognosis, and AHRF requiring mechanical ventilation is associated with substantial mortality. Persistent impaired gas exchange leading to hypoxemia often warrants the prolonged administration of a high fraction of inspired oxygen (FiO2). In SARS-CoV-2 AHRF, systemic vasculopathy with lung microthrombosis and microangiopathy further exacerbates poor gas exchange due to alveolar inflammation and oedema. Capillary congestion with microthrombosis is a common autopsy finding in the lungs of patients who die with coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome. The need for a high FiO2 to normalise arterial hypoxemia and tissue hypoxia can result in alveolar hyperoxia. This in turn can lead to local alveolar oxidative stress with associated inflammation, alveolar epithelial cell apoptosis, surfactant dysfunction, pulmonary vascular abnormalities, resorption atelectasis, and impairment of innate immunity predisposing to secondary bacterial infections. While oxygen is a life-saving treatment, alveolar hyperoxia may exacerbate pre-existing lung injury. In this review, we provide a summary of oxygen toxicity mechanisms, evaluating the consequences of alveolar hyperoxia in COVID-19 and propose established and potential exploratory treatment pathways to minimise alveolar hyperoxia.
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Affiliation(s)
- Ahilanandan Dushianthan
- NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Luke Bracegirdle
- NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Rebecca Cusack
- NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Andrew F Cumpstey
- NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Anthony D Postle
- NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Michael P W Grocott
- NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
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Dushianthan A, Grocott MPW, Murugan GS, Wilkinson TMA, Postle AD. Pulmonary Surfactant in Adult ARDS: Current Perspectives and Future Directions. Diagnostics (Basel) 2023; 13:2964. [PMID: 37761330 PMCID: PMC10528901 DOI: 10.3390/diagnostics13182964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a major cause of hypoxemic respiratory failure in adults, leading to the requirement for mechanical ventilation and poorer outcomes. Dysregulated surfactant metabolism and function are characteristic of ARDS. A combination of alveolar epithelial damage leading to altered surfactant synthesis, secretion, and breakdown with increased functional inhibition from overt alveolar inflammation contributes to the clinical features of poor alveolar compliance and alveolar collapse. Quantitative and qualitative alterations in the bronchoalveolar lavage and tracheal aspirate surfactant composition contribute to ARDS pathogenesis. Compared to neonatal respiratory distress syndrome (nRDS), replacement studies of exogenous surfactants in adult ARDS suggest no survival benefit. However, these studies are limited by disease heterogeneity, variations in surfactant preparations, doses, and delivery methods. More importantly, the lack of mechanistic understanding of the exact reasons for dysregulated surfactant remains a significant issue. Moreover, studies suggest an extremely short half-life of replaced surfactant, implying increased catabolism. Refining surfactant preparations and delivery methods with additional co-interventions to counteract surfactant inhibition and degradation has the potential to enhance the biophysical characteristics of surfactant in vivo.
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Affiliation(s)
- Ahilanandan Dushianthan
- National Institute for Health Research (NIHR) Southampton Biomedical Research Centre, University Hospital Southampton National Health System Foundation Trust, Southampton SO16 6YD, UK; (M.P.W.G.); (T.M.A.W.); (A.D.P.)
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Michael P. W. Grocott
- National Institute for Health Research (NIHR) Southampton Biomedical Research Centre, University Hospital Southampton National Health System Foundation Trust, Southampton SO16 6YD, UK; (M.P.W.G.); (T.M.A.W.); (A.D.P.)
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | | | - Tom M. A. Wilkinson
- National Institute for Health Research (NIHR) Southampton Biomedical Research Centre, University Hospital Southampton National Health System Foundation Trust, Southampton SO16 6YD, UK; (M.P.W.G.); (T.M.A.W.); (A.D.P.)
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Anthony D. Postle
- National Institute for Health Research (NIHR) Southampton Biomedical Research Centre, University Hospital Southampton National Health System Foundation Trust, Southampton SO16 6YD, UK; (M.P.W.G.); (T.M.A.W.); (A.D.P.)
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
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Fan LC, McConn K, Plataki M, Kenny S, Williams NC, Kim K, Quirke JA, Chen Y, Sauler M, Möbius ME, Chung KP, Area Gomez E, Choi AM, Xu JF, Cloonan SM. Alveolar type II epithelial cell FASN maintains lipid homeostasis in experimental COPD. JCI Insight 2023; 8:e163403. [PMID: 37606038 PMCID: PMC10543729 DOI: 10.1172/jci.insight.163403] [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: 07/19/2022] [Accepted: 07/10/2023] [Indexed: 08/23/2023] Open
Abstract
Alveolar epithelial type II (AEC2) cells strictly regulate lipid metabolism to maintain surfactant synthesis. Loss of AEC2 cell function and surfactant production are implicated in the pathogenesis of the smoking-related lung disease chronic obstructive pulmonary disease (COPD). Whether smoking alters lipid synthesis in AEC2 cells and whether altering lipid metabolism in AEC2 cells contributes to COPD development are unclear. In this study, high-throughput lipidomic analysis revealed increased lipid biosynthesis in AEC2 cells isolated from mice chronically exposed to cigarette smoke (CS). Mice with a targeted deletion of the de novo lipogenesis enzyme, fatty acid synthase (FASN), in AEC2 cells (FasniΔAEC2) exposed to CS exhibited higher bronchoalveolar lavage fluid (BALF) neutrophils, higher BALF protein, and more severe airspace enlargement. FasniΔAEC2 mice exposed to CS had lower levels of key surfactant phospholipids but higher levels of BALF ether phospholipids, sphingomyelins, and polyunsaturated fatty acid-containing phospholipids, as well as increased BALF surface tension. FasniΔAEC2 mice exposed to CS also had higher levels of protective ferroptosis markers in the lung. These data suggest that AEC2 cell FASN modulates the response of the lung to smoke by regulating the composition of the surfactant phospholipidome.
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Affiliation(s)
- Li-Chao Fan
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Keith McConn
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
| | - Maria Plataki
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
- NewYork-Presbyterian Hospital, Weill Cornell Medicine, New York, New York, USA
| | - Sarah Kenny
- School of Medicine, Trinity Biomedical Sciences Institute, and
| | | | - Kihwan Kim
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
| | | | - Yan Chen
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Maor Sauler
- Pulmonary, Critical Care and Sleep Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | | | - Kuei-Pin Chung
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
- Department of Laboratory Medicine, National Taiwan University College of Medicine, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Estela Area Gomez
- Division of Neuromuscular Medicine, Department of Neurology, Columbia University Irving Medical Center, Neurological Institute, New York, New York, USA
- Center for Biological Research “Margarita Salas”, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Augustine M.K. Choi
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
- NewYork-Presbyterian Hospital, Weill Cornell Medicine, New York, New York, USA
| | - Jin-Fu Xu
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Suzanne M. Cloonan
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York, USA
- School of Medicine, Trinity Biomedical Sciences Institute, and
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6
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Lock MC, Botting KJ, Allison BJ, Niu Y, Ford SG, Murphy MP, Orgeig S, Giussani DA, Morrison JL. MitoQ as an antenatal antioxidant treatment improves markers of lung maturation in healthy and hypoxic pregnancy. J Physiol 2023; 601:3647-3665. [PMID: 37467062 PMCID: PMC10952154 DOI: 10.1113/jp284786] [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: 04/03/2023] [Accepted: 07/04/2023] [Indexed: 07/21/2023] Open
Abstract
Chronic fetal hypoxaemia is a common pregnancy complication that increases the risk of infants experiencing respiratory complications at birth. In turn, chronic fetal hypoxaemia promotes oxidative stress, and maternal antioxidant therapy in animal models of hypoxic pregnancy has proven to be protective with regards to fetal growth and cardiovascular development. However, whether antenatal antioxidant therapy confers any benefit on lung development in complicated pregnancies has not yet been investigated. Here, we tested the hypothesis that maternal antenatal treatment with MitoQ will protect the developing lung in hypoxic pregnancy in sheep, a species with similar fetal lung developmental milestones as humans. Maternal treatment with MitoQ during late gestation promoted fetal pulmonary surfactant maturation and an increase in the expression of lung mitochondrial complexes III and V independent of oxygenation. Maternal treatment with MitoQ in hypoxic pregnancy also increased the expression of genes regulating liquid reabsorption in the fetal lung. These data support the hypothesis tested and suggest that MitoQ as an antenatal targeted antioxidant treatment may improve lung maturation in the late gestation fetus. KEY POINTS: Chronic fetal hypoxaemia promotes oxidative stress, and maternal antioxidant therapy in hypoxic pregnancy has proven to be protective with regards to fetal growth and cardiovascular development. MitoQ is a targeted antioxidant that uses the cell and the mitochondrial membrane potential to accumulate within the mitochondria. Treatment of healthy or hypoxic pregnancy with MitoQ, increases the expression of key molecules involved in surfactant maturation, lung liquid reabsorption and in mitochondrial proteins driving ATP synthesis in the fetal sheep lung. There were no detrimental effects of MitoQ treatment alone on the molecular components measured in the present study, suggesting that maternal antioxidant treatment has no effect on other components of normal maturation of the surfactant system.
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Affiliation(s)
- Mitchell C. Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health ScienceUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Kimberley J. Botting
- Department of Physiology, Development & NeuroscienceUniversity of CambridgeCambridgeUK
| | - Beth J. Allison
- Department of Physiology, Development & NeuroscienceUniversity of CambridgeCambridgeUK
| | - Youguo Niu
- Department of Physiology, Development & NeuroscienceUniversity of CambridgeCambridgeUK
| | - Sage G. Ford
- Department of Physiology, Development & NeuroscienceUniversity of CambridgeCambridgeUK
| | | | - Sandra Orgeig
- UniSA: Clinical and Health ScienceUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Dino A. Giussani
- Department of Physiology, Development & NeuroscienceUniversity of CambridgeCambridgeUK
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health ScienceUniversity of South AustraliaAdelaideSouth AustraliaAustralia
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Ben Anes A, Ben Nasr H, Tabka Z, Tabka O, Zaouali M, Chahed K. Plasma Lipid Profiling Identifies Phosphatidylcholine 34:3 and Triglyceride 52:3 as Potential Markers Associated with Disease Severity and Oxidative Status in Chronic Obstructive Pulmonary Disease. Lung 2022; 200:495-503. [PMID: 35816208 DOI: 10.1007/s00408-022-00552-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/20/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE To identify plasma alterations in lipid species in patients with chronic obstructive pulmonary disease (COPD), as well as, relationships with smoking status, oxidative and inflammatory markers. METHODS Plasma was obtained from 100 patients with COPD and 120 healthy controls. Pulmonary function was assessed by plethysmography. Serum levels of IL-6 and TNF-α were determined by ELISA. Oxidative stress parameters were measured using standard methods. Lipids were extracted then analyzed by Matrix-Assisted Laser Desorption and Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF-TOF-MS). RESULTS More than 40 lipid compounds were identified within plasma samples. Among these 19 lipid species including plasmalogens (PC O-), phosphatidylcholines (PC), and triglycerides (TG) were significantly altered in COPD. A decreased expression of PC O- (36:1, 36:2, 36:3, 36:4, 38:4, 38:5) species was found in patients with different severities compared to healthy controls. There was also a decrease in PC (34:3, 36:0, 36:4, 36:5, 40:6, 40:7) species in COPD patients. PC (34:3) levels were positively correlated with disease progression and pulmonary function decline (forced expiratory volume in 1 s (FEV1)) (r = 0.84, p < 0.001) and inversely correlated with thiobarbituric acid-reactive substances (TBARS) (r = - 0.77, p < 0.001). TG (50:0, 50:1, 52:1, 52:2, 52:3, 52:4, 54:4) species were altered in COPD patients and in those with advanced disease stages. Significant correlations between FEV1, TBARS, peroxynitrite, and TG (52:3) were found among COPD patients (r = - 0.69; r = 0.86; r = 0.77, p < 0.001, respectively). CONCLUSION PC (34:3) and TG (52:3) could be potential lipid signatures of COPD that correlate with altered pulmonary function and oxidative status.
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Affiliation(s)
- Amel Ben Anes
- Research Laboratory (LR19ES09): Exercise Physiology and Pathophysiology - From the Integrated to the Molecular Biology, Medicine and Health, Faculty of Medicine of Sousse, University of Sousse, 4002, Sousse, Tunisia.
| | - Hela Ben Nasr
- Research Laboratory (LR19ES09): Exercise Physiology and Pathophysiology - From the Integrated to the Molecular Biology, Medicine and Health, Faculty of Medicine of Sousse, University of Sousse, 4002, Sousse, Tunisia
- Higher Institute of Nursing Sciences, Sousse, Tunisia
| | - Zouhair Tabka
- Research Laboratory (LR19ES09): Exercise Physiology and Pathophysiology - From the Integrated to the Molecular Biology, Medicine and Health, Faculty of Medicine of Sousse, University of Sousse, 4002, Sousse, Tunisia
| | - Oussama Tabka
- Research Laboratory (LR19ES09): Exercise Physiology and Pathophysiology - From the Integrated to the Molecular Biology, Medicine and Health, Faculty of Medicine of Sousse, University of Sousse, 4002, Sousse, Tunisia
| | - Monia Zaouali
- Research Laboratory (LR19ES09): Exercise Physiology and Pathophysiology - From the Integrated to the Molecular Biology, Medicine and Health, Faculty of Medicine of Sousse, University of Sousse, 4002, Sousse, Tunisia
| | - Karim Chahed
- Research Laboratory (LR19ES09): Exercise Physiology and Pathophysiology - From the Integrated to the Molecular Biology, Medicine and Health, Faculty of Medicine of Sousse, University of Sousse, 4002, Sousse, Tunisia
- Faculty of Sciences of Sfax, Sfax, Tunisia
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Pioselli B, Salomone F, Mazzola G, Amidani D, Sgarbi E, Amadei F, Murgia X, Catinella S, Villetti G, De Luca D, Carnielli V, Civelli M. Pulmonary surfactant: a unique biomaterial with life-saving therapeutic applications. Curr Med Chem 2021; 29:526-590. [PMID: 34525915 DOI: 10.2174/0929867328666210825110421] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/26/2021] [Accepted: 06/29/2021] [Indexed: 11/22/2022]
Abstract
Pulmonary surfactant is a complex lipoprotein mixture secreted into the alveolar lumen by type 2 pneumocytes, which is composed by tens of different lipids (approximately 90% of its entire mass) and surfactant proteins (approximately 10% of the mass). It is crucially involved in maintaining lung homeostasis by reducing the values of alveolar liquid surface tension close to zero at end-expiration, thereby avoiding the alveolar collapse, and assembling a chemical and physical barrier against inhaled pathogens. A deficient amount of surfactant or its functional inactivation is directly linked to a wide range of lung pathologies, including the neonatal respiratory distress syndrome. This paper reviews the main biophysical concepts of surfactant activity and its inactivation mechanisms, and describes the past, present and future roles of surfactant replacement therapy, focusing on the exogenous surfactant preparations marketed worldwide and new formulations under development. The closing section describes the pulmonary surfactant in the context of drug delivery. Thanks to its peculiar composition, biocompatibility, and alveolar spreading capability, the surfactant may work not only as a shuttle to the branched anatomy of the lung for other drugs but also as a modulator for their release, opening to innovative therapeutic avenues for the treatment of several respiratory diseases.
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Affiliation(s)
| | | | | | | | - Elisa Sgarbi
- Preclinical R&D, Chiesi Farmaceutici, Parma. Italy
| | | | - Xabi Murgia
- Department of Biotechnology, GAIKER Technology Centre, Zamudio. Spain
| | | | | | - Daniele De Luca
- Division of Pediatrics and Neonatal Critical Care, Antoine Béclère Medical Center, APHP, South Paris University Hospitals, Paris, France; Physiopathology and Therapeutic Innovation Unit-U999, South Paris-Saclay University, Paris. France
| | - Virgilio Carnielli
- Division of Neonatology, G Salesi Women and Children's Hospital, Polytechnical University of Marche, Ancona. Italy
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Thorenoor N, Kawasawa YI, Gandhi CK, Zhang X, Floros J. Differential Impact of Co-expressed SP-A1/SP-A2 Protein on AM miRNome; Sex Differences. Front Immunol 2019; 10:1960. [PMID: 31475015 PMCID: PMC6707024 DOI: 10.3389/fimmu.2019.01960] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/02/2019] [Indexed: 12/04/2022] Open
Abstract
In humans there are two surfactant protein A (SP-A) functional genes SFTPA1 and SFTPA2 encoding innate immune molecules, SP-A1 and SP-A2, respectively, with numerous genetic variants each. SP-A interacts and regulates many of the functions of alveolar macrophages (AM). It is shown that SP-A variants differ in their ability to regulate the AM miRNome in response to oxidative stress (OxS). Because humans have both SP-A gene products, we were interested to determine the combined effect of co-expressed SP-A1/SP-A2 (co-ex) in response to ozone (O3) induced OxS on AM miRNome. Human transgenic (hTG) mice, carrying both SP-A1/SP-A2 (6A2/1A0, co-ex) and SP-A- KO were utilized. The hTG and KO mice were exposed to filtered air (FA) or O3 and miRNA levels were measured after AM isolation with or without normalization to KO. We found: (i) The AM miRNome of co-ex males and females in response to OxS to be largely downregulated after normalization to KO, but after Bonferroni multiple comparison analysis only in females the AM miRNome remained significantly different compared to control (FA); (ii) The targets of the significantly changed miRNAs were downregulated in females and upregulated in males; (iii) Several of the validated mRNA targets were involved in pro-inflammatory response, anti-apoptosis, cell cycle, cellular growth and proliferation; (iv) The AM of SP-A2 male, shown, previously to have major effect on the male AM miRNome in response to OxS, shared similarities with the co-ex, namely in pathways involved in the pro-inflammatory response and anti-apoptosis but also exhibited differences with the cell-cycle, growth, and proliferation pathway being involved in co-ex and ROS homeostasis in SP-A2 male. We speculate that the presence of both gene products vs. single gene products differentially impact the AM responses in males and females in response to OxS.
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Affiliation(s)
- Nithyananda Thorenoor
- Department of Pediatrics, Center for Host Defense, Inflammation, and Lung Disease Research, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Yuka Imamura Kawasawa
- Departments of Pharmacology and Biochemistry and Molecular Biology, Institute for Personalized Medicine, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Chintan K Gandhi
- Department of Pediatrics, Center for Host Defense, Inflammation, and Lung Disease Research, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Xuesheng Zhang
- Department of Pediatrics, Center for Host Defense, Inflammation, and Lung Disease Research, The Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Joanna Floros
- Department of Pediatrics, Center for Host Defense, Inflammation, and Lung Disease Research, The Pennsylvania State University College of Medicine, Hershey, PA, United States.,Department of Obstetrics and Gynecology, The Pennsylvania State University College of Medicine, Hershey, PA, United States
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10
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Davies MJ, Leach AG, Fullwood D, Mistry D, Hope A. The pH dependent interaction between nicotine and simulated pulmonary surfactant monolayers with associated molecular modelling. SURF INTERFACE ANAL 2017. [DOI: 10.1002/sia.6244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michael J. Davies
- The School of Pharmacy and Biomolecular Sciences; Liverpool John Moores University; Liverpool L3 3AF UK
| | - Andrew G. Leach
- The School of Pharmacy and Biomolecular Sciences; Liverpool John Moores University; Liverpool L3 3AF UK
| | - Danielle Fullwood
- The School of Pharmacy and Biomolecular Sciences; Liverpool John Moores University; Liverpool L3 3AF UK
| | - Dinesh Mistry
- The School of Pharmacy and Biomolecular Sciences; Liverpool John Moores University; Liverpool L3 3AF UK
| | - Alexandra Hope
- The School of Pharmacy and Biomolecular Sciences; Liverpool John Moores University; Liverpool L3 3AF UK
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11
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Echaide M, Autilio C, Arroyo R, Perez-Gil J. Restoring pulmonary surfactant membranes and films at the respiratory surface. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1725-1739. [PMID: 28341439 DOI: 10.1016/j.bbamem.2017.03.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/14/2017] [Accepted: 03/19/2017] [Indexed: 02/08/2023]
Abstract
Pulmonary surfactant is a complex of lipids and proteins assembled and secreted by the alveolar epithelium into the thin layer of fluid coating the respiratory surface of lungs. There, surfactant forms interfacial films at the air-water interface, reducing dramatically surface tension and thus stabilizing the air-exposed interface to prevent alveolar collapse along respiratory mechanics. The absence or deficiency of surfactant produces severe lung pathologies. This review describes some of the most important surfactant-related pathologies, which are a cause of high morbidity and mortality in neonates and adults. The review also updates current therapeutic approaches pursuing restoration of surfactant operative films in diseased lungs, mainly through supplementation with exogenous clinical surfactant preparations. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.
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Affiliation(s)
- Mercedes Echaide
- Dept. Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Chiara Autilio
- Dept. Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Raquel Arroyo
- Dept. Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, Madrid, Spain
| | - Jesus Perez-Gil
- Dept. Biochemistry, Faculty of Biology, and Research Institute "Hospital 12 de Octubre", Complutense University, Madrid, Spain.
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12
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Ogunbileje JO, Nawgiri RS, Anetor JI, Akinosun OM, Farombi EO, Okorodudu AO. Particles internalization, oxidative stress, apoptosis and pro-inflammatory cytokines in alveolar macrophages exposed to cement dust. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2014; 37:1060-1070. [PMID: 24769344 DOI: 10.1016/j.etap.2014.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 03/24/2014] [Accepted: 03/30/2014] [Indexed: 06/03/2023]
Abstract
Exposure to cement dust is one of the most common occupational dust exposures worldwide, but the mechanism of toxicity has not been fully elucidated. Cement dust (N) and clinker (C) samples collected from Nigeria and another sample of cement dust (U) collected from USA were evaluated using alveolar macrophage (NR8383) cell culture to determine the contribution of different sources of cement dust in the severity of cement dust toxicity. Cement dust particles internalization and morphologic alterations using transmission electron microscopy (TEM), cytotoxicity, apoptotic cells induction, intracellular reactive oxygen species generation, glutathione reduction, TNF-α, IL-1β, and CINC-3 secretion in alveolar macrophages (NR8383) exposed to cement dust and clinker samples were determined. Particles were internalized into the cytoplasmic vacuoles, with cells exposed to U showing increased cell membrane blebbing. Also, NR8383 exposed to U show more significant ROS generation, apoptotic cells induction and decreased glutathione. Interleukin-1β and TNF-α secretion were significantly more in cells exposed to both cement dust samples compared with clinker, while CINC-3 secretion was significantly more in cells exposed to clinker (p < 0.05). Endocytosis, oxidative stress induced-apoptosis and induction of pro-inflammatory cytokines may be key mechanisms of cement dust immunotoxicity in the lung and toxicity may be factory dependent.
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Affiliation(s)
- J O Ogunbileje
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Department of Chemical Pathology and Immunology, College of Medicine, University of Ibadan, Ibadan, Nigeria.
| | - R S Nawgiri
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - J I Anetor
- Department of Chemical Pathology and Immunology, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - O M Akinosun
- Department of Chemical Pathology and Immunology, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - E O Farombi
- Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - A O Okorodudu
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA.
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13
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Cataldi M, Sblendorio V, Leo A, Piazza O. Biofilm-dependent airway infections: a role for ambroxol? Pulm Pharmacol Ther 2013; 28:98-108. [PMID: 24252805 DOI: 10.1016/j.pupt.2013.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 10/31/2013] [Accepted: 11/11/2013] [Indexed: 11/16/2022]
Abstract
Biofilms are a key factor in the development of both acute and chronic airway infections. Their relevance is well established in ventilator associated pneumonia, one of the most severe complications in critically ill patients, and in cystic fibrosis, the most common lethal genetic disease in Caucasians. Accumulating evidence suggests that biofilms could have also a role in chronic obstructive pulmonary disease and their involvement in bronchiectasis has been proposed as well. When they grow in biofilms, microorganisms become multidrug-resistant. Therefore the treatment of biofilm-dependent airway infections is problematic. Indeed, it still largely based on measures aiming to prevent the formation of biofilms or remove them once that they are formed. Here we review recent evidence suggesting that the mucokinetic drug ambroxol has specific anti-biofilm properties. We also discuss how additional pharmacological properties of this drug could be beneficial in biofilm-dependent airway infections. Specifically, we review the evidence showing that: 1-ambroxol exerts anti-inflammatory effects by inhibiting at multiple levels the activity of neutrophils, and 2-it improves mucociliary clearance by interfering with the activity of airway epithelium ion channels and transporters including sodium/bicarbonate and sodium/potassium/chloride cotransporters, cystic fibrosis transmembrane conductance regulator and aquaporins. As a whole, the data that we review here suggest that ambroxol could be helpful in biofilm-dependent airway infections. However, considering the limited clinical evidence available up to date, further clinical studies are required to support the use of ambroxol in these diseases.
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Affiliation(s)
- M Cataldi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, Federico II University of Naples, Via Pansini 5, 80131 Napoli, Italy.
| | - V Sblendorio
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, Federico II University of Naples, Via Pansini 5, 80131 Napoli, Italy
| | - A Leo
- Department of Health Sciences, University Magna Græcia of Catanzaro, University Campus "Salvatore Venuta", Viale Europa, I-88100 Catanzaro, Italy
| | - O Piazza
- University of Salerno, Via Allende, 84081 Baronissi, Italy
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14
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Brink CB, Pretorius A, van Niekerk BP, Oliver DW, Venter DP. Studies on cellular resilience and adaptation following acute and repetitive exposure to ozone in cultured human epithelial (HeLa) cells. Redox Rep 2013; 13:87-100. [DOI: 10.1179/135100008x259187] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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15
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Kimura T, Shibata Y, Yamauchi K, Igarashi A, Inoue S, Abe S, Fujita K, Uosaki Y, Kubota I. Oxidized phospholipid, 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (PON-GPC), produced in the lung due to cigarette smoking, impairs immune function in macrophages. Lung 2011; 190:169-82. [PMID: 21986851 DOI: 10.1007/s00408-011-9331-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 09/25/2011] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Pulmonary innate immunity is impaired in cigarette smokers, because the abundant oxidants present in cigarette smoke (CS) cause injury to lung cells. Pulmonary surfactant is a unique material that is important roles in reducing surface tension in the lung and defending against invading pathogens. Oxidants reportedly cleave surfactant phospholipids, resulting in the production of oxidized phospholipids, such as 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (PON-GPC). Although oxidation of surfactant lipids is thought to be involved in the pathogenesis of smoking-related lung disease, there are no reports on the effect of oxidized surfactant lipid on the immune function of macrophages. We hypothesized that cigarette smoking elevates PON-GPC levels in the lung, and that PON-GPC impairs the innate immune function of macrophages. METHODS The levels of PON-GPC in bronchoalveolar lavage fluid (BALF) recovered from mice exposed to CS for 2 weeks (n = 7) were measured by liquid chromatography with electrospray-ionization tandem mass spectrometry. The effects of PON-GPC on inducibility of tumor necrosis factor (TNF)-α, nitric oxide (NO), and nicotinamide adenine dinucleotide phosphate (NADP(+)) production, as well as bactericidal activity, were investigated in RAW264.7 cells or primary alveolar macrophages. RESULTS The levels of PON-GPC in BALF of mice exposed to CS were significantly elevated, compared with those of control mice. PON-GPC attenuated TNF-α, NO, and NADP(+) production in macrophages on stimulation with LPS plus IFN-γ. PON-GPC treatment attenuated the phosphorylation of p38 mitogen-activated protein kinase (MAPK). In addition, PON-GPC reduced the bactericidal activity of RAW264.7 cells. CONCLUSIONS CS may attenuate innate immunity in the lungs through oxidization of surfactant phospholipids.
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Affiliation(s)
- Tomomi Kimura
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
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16
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Draenert A, Marquardt K, Inci I, Soltermann A, Weder W, Jungraithmayr W. Ischaemia-reperfusion injury in orthotopic mouse lung transplants - a scanning electron microscopy study. Int J Exp Pathol 2011; 92:18-25. [PMID: 21272104 DOI: 10.1111/j.1365-2613.2010.00752.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Lung ischaemia-reperfusion (I/R) injury remains a major cause of graft failure in lung transplantation (Tx). With the implementation of orthotopic lung Tx in mice, a physiological model on the base of a perfused and ventilated graft became available for the investigation of I/R injury. Using the scanning electron microscopy (SEM) technique, we here present an analysis of early and late morphological changes of pulmonary I/R injury. Syngeneic lungs were orthotopically transplanted between C57BL/6 mice. Grafts were exposed to 2 h of cold ischaemia. Transplants and right lungs were examined by SEM with corresponding haematoxylin-eosin histology 30 min and 4 h after reperfusion. Thirty minutes after reperfusion, the alveolar surface of transplants showed a discontinued lining of surfactant, while the lining of the non-transplanted lung was normal. Within the graft, leucocytes displayed an irregular surface with development of pseudopodia, and microvilli were detected on the membrane of pneumocytes. At 4 h after reperfusion, leucocytes significantly increased in numbers within the alveolar space. Also, the number of microvilli on pneumocytes increased significantly. Similar to these, the endothelium of vessels increasingly developed microvilli from 30 min towards 4 h after reperfusion. The airways of transplanted grafts showed mild changes with thickening of the bronchial epithelium and a destruction of kinocilia. Taken together, SEM detects pathological events of I/R that are previously not described in normal histology. These findings may influence the interpretation of studies investigating the I/R injury in the mouse model of lung Tx.
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Affiliation(s)
- Alice Draenert
- Division of Thoracic Surgery, University Hospital Zurich, Zurich, Switzerland
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17
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Zhao CZ, Fang XC, Wang D, Tang FD, Wang XD. Involvement of type II pneumocytes in the pathogenesis of chronic obstructive pulmonary disease. Respir Med 2011; 104:1391-5. [PMID: 20638828 DOI: 10.1016/j.rmed.2010.06.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2010] [Revised: 06/16/2010] [Accepted: 06/25/2010] [Indexed: 11/24/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality, but the cellular and molecular mechanisms are still not fully understood. Type II pneumocytes are identified as the synthesizing cells of the alveolar surfactant, which has important properties in maintaining alveolar and airway stability. Lung surfactant can reduce the surface tension and prevent alveolar collapse and the airway walls collapse. Pulmonary surfactant components play important roles in normal lung function and inflammation in the lung. Surfactant has furthermore been shown to modulate the process of innate host defense, including suppression of cytokine secretion and transcription factor activation, in the inflammatory network of COPD. Abnormalities of lung surfactant might be one of the mechanisms leading to increased airway resistance in COPD. The increased expression of Granzyme A and B was found in lung tissues of patients with COPD and type II pneumocytes was proposed to be involved in the pathogenesis of COPD. These novel findings provide new sights into the role of the type II pneumocytes in the pathogenesis of COPD.
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Affiliation(s)
- Chun-zhen Zhao
- Zhejiang Respiratory Drugs Research Laboratory of State Food and Drugs Administration of China, College of Medical Sciences, Zhejiang University, China
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18
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Sarker M, Rose J, McDonald M, Morrow MR, Booth V. Modifications to surfactant protein B structure and lipid interactions under respiratory distress conditions: consequences of tryptophan oxidation. Biochemistry 2010; 50:25-36. [PMID: 21128671 DOI: 10.1021/bi101426s] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
These studies detail the altered structure-function relationships caused by oxidation of surfactant protein B (SP-B), a mode of damage thought to be important in acute respiratory distress syndrome (ARDS), a common and frequently fatal condition. An 18-residue fragment comprising the N-terminal helix of SP-B was investigated in oxidized and unmodified forms by solution and solid-state nuclear magnetic resonance (NMR), circular dichroism (CD), and molecular dynamics (MD) simulation. Taken together, the results indicate that tryptophan oxidation causes substantial disruptions in helical structure and lipid interactions. The structural modifications induced by tryptophan oxidation were severe, with a reduction in helical extent from approximately three helical turns to, at most, one turn, and were observed in a variety of solvent environments, including sodium dodecyl sulfate (SDS) micelles, dodecyl phosphocholine (DPC) micelles, and a 40% hexafluoro-2-propanol (HFIP) aqueous solution. The unmodified peptide takes on an orientation within lipid bilayers that is tilted approximately 30° away from an in-plane position. Tryptophan oxidation causes significant modifications to the peptide-lipid interactions, and the peptide likely shifts to a more in-plane orientation within the lipids. Interestingly, the character of the disruptions to peptide-lipid interactions caused by tryptophan oxidation was highly dependent on the charge of the lipid headgroup.
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Affiliation(s)
- Muzaddid Sarker
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL, Canada
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19
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Verder H, Bohlin K, Kamper J, Lindwall R, Jonsson B. Nasal CPAP and surfactant for treatment of respiratory distress syndrome and prevention of bronchopulmonary dysplasia. Acta Paediatr 2009; 98:1400-8. [PMID: 19572989 DOI: 10.1111/j.1651-2227.2009.01413.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
UNLABELLED The Scandinavian approach is an effective combined treatment for respiratory distress syndrome (RDS) and prevention of bronchopulmonary dysplasia (BPD). It is composed of many individual parts. Of significant importance is the early treatment with nasal continuous positive airway pressure (nCPAP) and surfactant treatment. The approach may be supplemented with caffeine citrate and non-invasive positive pressure ventilation for apnoea. The low incidence of BPD seen as a consequence of the treatment strategy is mainly due to a reduced need for mechanical ventilation (MV). CONCLUSION Early-postnatal treatment with nCPAP and surfactant decreases the severity and mortality of RDS and BPD. This is mainly due to a diminished use of MV in the first days of life.
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Affiliation(s)
- Henrik Verder
- Department of Paediatrics, Holbaek University Hospital, University of Copenhagen, Holbaek, Denmark.
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20
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Stagos D, Umstead TM, Phelps DS, Skaltsounis L, Haroutounian S, Floros J, Kouretas D. Inhibition of ozone-induced SP-A oxidation by plant polyphenols. Free Radic Res 2009; 41:357-66. [PMID: 17364965 DOI: 10.1080/10715760601064714] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Surfactant protein-A (SP-A) is the best studied and most abundant of the protein components of lung surfactant and plays an important role in host defense of the lung. It has been shown that ozone-induced oxidation of SP-A protein changes its functional and biochemical properties. In the present study, eight plant polyphenols (three flavonoids, three hydroxycinnamic acids, and two hydroxybenzoic acids) known as strong antioxidants, were tested for their ability to inhibit ozone-induced SP-A oxidation as a mechanism for chemoprevention against lung damage. SP-A isolated from alveolar proteinosis patients was exposed to ozone (1 ppm) for 4 h. The flavonoids protected SP-A from oxidation in a dose dependent manner. ( - )-Epicatechin was the most potent flavonoid and exhibited inhibition of ozone-induced formation of carbonyls by 35% at a concentration as low as 5 microM. Hydroxybenzoic acids inhibited SP-A oxidation in a dose-dependent manner although they were less potent than flavonoids. On the other hand, hydroxycinnamic acids exhibited a different inhibitory pattern. Inhibition was observed only at medium concentrations. The results indicate that inhibition of SP-A oxidation by plant polyphenols may be a mechanism accounting for the protective activity of natural antioxidants against the effects of ozone exposure on lungs.
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Affiliation(s)
- Dimitrios Stagos
- Department of Biochemistry, University of Thessaly, Larissa, Greece
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21
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Albert S, Kubiak B, Nieman G. Protective Mechanical Ventilation: Lessons Learned From Alveolar Mechanics. Intensive Care Med 2009. [DOI: 10.1007/978-0-387-77383-4_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Johnson LN, Koval M. Cross-talk between pulmonary injury, oxidant stress, and gap junctional communication. Antioxid Redox Signal 2009; 11:355-67. [PMID: 18816185 PMCID: PMC2933150 DOI: 10.1089/ars.2008.2183] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Gap junction channels interconnect several different types of cells in the lung, ranging from the alveolar epithelium to the pulmonary vasculature, each of which expresses a unique subset of gap junction proteins (connexins). Major lung functions regulated by gap junctional communication include coordination of ciliary beat frequency and inflammation. Gap junctions help enable the alveolus to regulate surfactant secretion as an integrated system, in which type I cells act as mechanical sensors that transmit calcium transients to type II cells. Thus, disruption of epithelial gap junctional communication, particularly during acute lung injury, can interfere with these processes and increase the severity of injury. Consistent with this, connexin expression is altered during lung injury, and connexin-deficiency has a negative impact on the injury response and lung-growth control. It has recently been shown that alcohol abuse is a significant risk factor associated with acute respiratory distress syndrome. Oxidant stress and hormone-signaling cascades in the lung induced by prolonged alcohol ingestion are discussed, as well as the effects of these pathways on connexin expression and function.
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Affiliation(s)
- Latoya N Johnson
- Division of Pulmonary, Allergy and Critical Care Medicine, and Emory Alcohol and Lung Biology Center, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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23
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Stenger PC, Alonso C, Zasadzinski JA, Waring AJ, Jung CL, Pinkerton KE. Environmental tobacco smoke effects on lung surfactant film organization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1788:358-70. [PMID: 19118518 DOI: 10.1016/j.bbamem.2008.11.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 11/13/2008] [Accepted: 11/14/2008] [Indexed: 01/05/2023]
Abstract
Adsorption of the clinical lung surfactants (LS) Curosurf or Survanta from aqueous suspension to the air-water interface progresses from multi-bilayer aggregates through multilayer films to a coexistence between multilayer and monolayer domains. Exposure to environmental tobacco smoke (ETS) alters this progression as shown by Langmuir isotherms, fluorescence microscopy and atomic force microscopy (AFM). After 12 h of LS exposure to ETS, AFM images of Langmuir-Blodgett deposited films show that ETS reduces the amount of material near the interface and alters how surfactant is removed from the interface during compression. For Curosurf, ETS prevents refining of the film composition during cycling; this leads to higher minimum surface tensions. ETS also changes the morphology of the Curosurf film by reducing the size of condensed phase domains from 8-12 microm to approximately 2 microm, suggesting a decrease in the line tension between the domains. The minimum surface tension and morphology of the Survanta film are less impacted by ETS exposure, although the amount of material associated with the film is reduced in a similar way to Curosurf. Fluorescence and mass spectra of Survanta dispersions containing native bovine SP-B treated with ETS indicate the oxidative degradation of protein aromatic amino acid residue side chains. Native bovine SP-C isolated from ETS exposed Survanta had changes in molecular mass consistent with deacylation of the lipoprotein. Fourier Transform Infrared Spectroscopy (FTIR) characterization of the hydrophobic proteins from ETS treated Survanta dispersions show significant changes in the conformation of SP-B and SP-C that correlate with the altered surface activity and morphology of the lipid-protein film.
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Affiliation(s)
- Patrick C Stenger
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106-5080, USA
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Pauluhn J, Carson A, Costa DL, Gordon T, Kodavanti U, Last JA, Matthay MA, Pinkerton KE, Sciuto AM. Workshop Summary: Phosgene-Induced Pulmonary Toxicity Revisited: Appraisal of Early and Late Markers of Pulmonary Injury From Animal Models With Emphasis on Human Significance. Inhal Toxicol 2008; 19:789-810. [PMID: 17687713 DOI: 10.1080/08958370701479133] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A workshop was held February 14, 2007, in Arlington, VA, under the auspices of the Phosgene Panel of the American Chemistry Council. The objective of this workshop was to convene inhalation toxicologists and medical experts from academia, industry and regulatory authorities to critically discuss past and recent inhalation studies of phosgene in controlled animal models. This included presentations addressing the benefits and limitations of rodent (mice, rats) and nonrodent (dogs) species to study concentration x time (C x t) relationships of acute and chronic types of pulmonary changes. Toxicological endpoints focused on the primary pulmonary effects associated with the acute inhalation exposure to phosgene gas and responses secondary to injury. A consensus was reached that the phosgene-induced increased pulmonary extravasation of fluid and protein can suitably be probed by bronchoalveolar lavage (BAL) techniques. BAL fluid analyses rank among the most sensitive methods to detect phosgene-induced noncardiogenic, pulmonary high-permeability edema following acute inhalation exposure. Maximum protein concentrations in BAL fluid occurred within 1 day after exposure, typically followed by a latency period up to about 15 h, which is reciprocal to the C x t exposure relationship. The C x t relationship was constant over a wide range of concentrations and single exposure durations. Following intermittent, repeated exposures of fixed duration, increased tolerance to recurrent exposures occurred. For such exposure regimens, chronic effects appear to be clearly dependent on the concentration rather than the cumulative concentration x time relationship. The threshold C x t product based on an increased BAL fluid protein following single exposure was essentially identical to the respective C x t product following subchronic exposure of rats based on increased pulmonary collagen and influx of inflammatory cells. Thus, the chronic outcome appears to be contingent upon the acute pulmonary threshold dose. Exposure concentrations high enough to elicit an increased acute extravasation of plasma constituents into the alveolus may also be associated with surfactant dysfunction, intra-alveolar accumulation of fibrin and collagen, and increased recruitment and activation of inflammatory cells. Although the exact mechanisms of toxicity have not yet been completely elucidated, consensus was reached that the acute pulmonary toxicity of phosgene gas is consistent with a simple, irritant mode of action at the site of its initial deposition/retention. The acute concentration x time mortality relationship of phosgene gas in rats is extremely steep, which is typical for a local, directly acting pulmonary irritant gas. Due to the high lipophilicity of phosgene gas, it efficiently penetrates the lower respiratory tract. Indeed, more recent published evidence from animals or humans has not revealed appreciable irritant responses in central and upper airways, unless exposure was to almost lethal concentrations. The comparison of acute inhalation studies in rats and dogs with focus on changes in BAL fluid constituents demonstrates that dogs are approximately three to four times less susceptible to phosgene than rats under methodologically similar conditions. There are data to suggest that the dog may be useful particularly for the study of mechanisms associated with the acute extravasation of plasma constituents because of its size and general morphology and physiology of the lung as well as its oronasal breathing patterns. However, the study of the long-term sequelae of acute effects is experimentally markedly more demanding in dogs as compared to rats, precluding the dog model to be applied on a routine base. The striking similarity of threshold concentrations from single exposure (increased protein in BAL fluid) and repeated-exposure 3-mo inhalation studies (increased pulmonary collagen deposition) in rats supports the notion that chronic changes depend on acute threshold mechanisms.
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Affiliation(s)
- J Pauluhn
- Bayer Schering Pharma, Wuppertal, Germany.
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Schmidt R, Markart P, Ruppert C, Wygrecka M, Kuchenbuch T, Walmrath D, Seeger W, Guenther A. Time-dependent changes in pulmonary surfactant function and composition in acute respiratory distress syndrome due to pneumonia or aspiration. Respir Res 2007; 8:55. [PMID: 17662121 PMCID: PMC1950506 DOI: 10.1186/1465-9921-8-55] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 07/27/2007] [Indexed: 01/11/2023] Open
Abstract
Background Alterations to pulmonary surfactant composition have been encountered in the Acute Respiratory Distress Syndrome (ARDS). However, only few data are available regarding the time-course and duration of surfactant changes in ARDS patients, although this information may largely influence the optimum design of clinical trials addressing surfactant replacement therapy. We therefore examined the time-course of surfactant changes in 15 patients with direct ARDS (pneumonia, aspiration) over the first 8 days after onset of mechanical ventilation. Methods Three consecutive bronchoalveolar lavages (BAL) were performed shortly after intubation (T0), and four days (T1) and eight days (T2) after intubation. Fifteen healthy volunteers served as controls. Phospholipid-to-protein ratio in BAL fluids, phospholipid class profiles, phosphatidylcholine (PC) molecular species, surfactant proteins (SP)-A, -B, -C, -D, and relative content and surface tension properties of large surfactant aggregates (LA) were assessed. Results At T0, a severe and highly significant reduction in SP-A, SP-B and SP-C, the LA fraction, PC and phosphatidylglycerol (PG) percentages, and dipalmitoylation of PC (DPPC) was encountered. Surface activity of the LA fraction was greatly impaired. Over time, significant improvements were encountered especially in view of LA content, DPPC, PG and SP-A, but minimum surface tension of LA was not fully restored (15 mN/m at T2). A highly significant correlation was observed between PaO2/FiO2 and minimum surface tension (r = -0.83; p < 0.001), SP-C (r = 0.64; p < 0.001), and DPPC (r = 0.59; p = 0.003). Outcome analysis revealed that non-survivors had even more unfavourable surfactant properties as compared to survivors. Conclusion We concluded that a profound impairment of pulmonary surfactant composition and function occurs in the very early stage of the disease and only gradually resolves over time. These observations may explain why former surfactant replacement studies with a short treatment duration failed to improve outcome and may help to establish optimal composition and duration of surfactant administration in future surfactant replacement studies in acute lung injury.
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Affiliation(s)
- Reinhold Schmidt
- University of Giessen Lung Center (UGLC), Medical Clinic II, Giessen, Germany
| | - Philipp Markart
- University of Giessen Lung Center (UGLC), Medical Clinic II, Giessen, Germany
| | - Clemens Ruppert
- University of Giessen Lung Center (UGLC), Medical Clinic II, Giessen, Germany
| | - Malgorzata Wygrecka
- University of Giessen Lung Center (UGLC), Medical Clinic II, Giessen, Germany
| | - Tim Kuchenbuch
- University of Giessen Lung Center (UGLC), Medical Clinic II, Giessen, Germany
| | - Dieter Walmrath
- University of Giessen Lung Center (UGLC), Medical Clinic II, Giessen, Germany
| | - Werner Seeger
- University of Giessen Lung Center (UGLC), Medical Clinic II, Giessen, Germany
| | - Andreas Guenther
- University of Giessen Lung Center (UGLC), Medical Clinic II, Giessen, Germany
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Haque R, Umstead TM, Ponnuru P, Guo X, Hawgood S, Phelps DS, Floros J. Role of surfactant protein-A (SP-A) in lung injury in response to acute ozone exposure of SP-A deficient mice. Toxicol Appl Pharmacol 2006; 220:72-82. [PMID: 17307210 PMCID: PMC1906716 DOI: 10.1016/j.taap.2006.12.017] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Revised: 12/01/2006] [Accepted: 12/02/2006] [Indexed: 10/23/2022]
Abstract
Millions are exposed to ozone levels above recommended limits, impairing lung function, causing epithelial damage and inflammation, and predisposing some individuals to pneumonia, asthma, and other lung conditions. Surfactant protein-A (SP-A) plays a role in host defense, the regulation of inflammation, and repair of tissue damage. We tested the hypothesis that the lungs of SP-A(-/-) (KO) mice are more susceptible to ozone-induced damage. We compared the effects of ozone on KO and wild type (WT) mice on the C57BL/6 genetic background by exposing them to 2 parts/million of ozone for 3 or 6 h and sacrificing them 0, 4, and 24 h later. Lungs were subject to bronchoalveolar lavage (BAL) or used to measure endpoints of oxidative stress and inflammation. Despite more total protein in BAL of KO mice after a 3 h ozone exposure, WT mice had increased oxidation of protein and had oxidized SP-A dimers. In KO mice there was epithelial damage as assessed by increased LDH activity and there was increased phospholipid content. In WT mice there were more BAL PMNs and elevated macrophage inflammatory protein (MIP)-2 and monocyte chemoattractant protein (MCP)-1. Changes in MIP-2 and MCP-1 were observed in both KO and WT, however mRNA levels differed. In KO mice MIP-2 mRNA levels changed little with ozone, but in WT levels they were significantly increased. In summary, several aspects of the inflammatory response differ between WT and KO mice. These in vivo findings appear to implicate SP-A in regulating inflammation and limiting epithelial damage in response to ozone exposure.
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Affiliation(s)
- Rizwanul Haque
- Departments of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Todd M. Umstead
- Departments of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Padmavathi Ponnuru
- Departments of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Xiaoxuan Guo
- Departments of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Samuel Hawgood
- Department of Pediatrics and Cardiovascular Research Institute, University of California, San Francisco, CA 94143
| | - David S. Phelps
- Departments of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Joanna Floros
- Departments of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA 17033
- Departments of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033
- Departments of Obstetrics and Gynecology, Pennsylvania State University College of Medicine, Hershey, PA 17033
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Lindwall R, Svensson ME, Frostell CG, Eksborg S, Gustafsson LE. Workplace NO and NO2 during combined treatment of infants with nasal CPAP and NO. Intensive Care Med 2006; 32:2034-41. [PMID: 17043849 DOI: 10.1007/s00134-006-0393-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2006] [Accepted: 09/08/2006] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine the workplace concentrations of NO and NO(2) in and around a paediatric incubator during inhaled NO (iNO) treatment and during an accidental emptying of NO cylinders into room air. DESIGN We simulated iNO-nasal CPAP treatment in order to assess the impact on the occupational environment. Furthermore, two full NO cylinders for therapy, 1,000 ppm, 20 litres, 150 bar and 400 ppm, 10 litres, 150 bar, were emptied as rapidly as possible into an intensive care unit (ICU) room. SETTING University hospital ICU. MEASUREMENTS AND RESULTS To correctly gauge the contribution from iNO-CPAP we constructed a system measuring breathing zone and room ventilation inlet-outlet values during a 10-ppm iNO treatment of a simulated infant. Maximal breathing zone values were 17.9 +/- 7.0 (mean +/- 95% CI) ppb for NO and 25.2 +/- 4.8 ppb for NO(2). If room inlet values were subtracted, the contributions to breathing zone values emanating from iNO-CPAP were 14.8 +/- 4.6 ppb for NO and 14.6 +/- 4.6 ppb for NO(2). At the ventilation outlet the maximal contributions were 4.2 +/- 2.9 ppb NO and 9.6 +/- 4.3 ppb NO(2). During rapid total release of a gas cylinder in the ICU room, simulating an accident, we found transient NO levels comparable to the high therapeutic dosing range, but only low NO(2) levels. CONCLUSIONS Neither 8-h time-weighted average (TWA) nor 15 min short-term exposure limits (STEL) were exceeded during normal operation or during a simulated accident. The contribution of nitrogen oxides from treatment to workplace air were minor compared to those from ambient air.
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Affiliation(s)
- Robert Lindwall
- Karolinska Institutet, Department of Clinical Sciences, Division of Anaesthesia and Intensive Care, Danderyd University Hospital, Stockholm, Sweden.
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Schmelzer KR, Wheelock ÅM, Dettmer K, Morin D, Hammock BD. The role of inflammatory mediators in the synergistic toxicity of ozone and 1-nitronaphthalene in rat airways. ENVIRONMENTAL HEALTH PERSPECTIVES 2006; 114:1354-60. [PMID: 16966088 PMCID: PMC1570074 DOI: 10.1289/ehp.8373] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Ambient air is polluted with a mixture of pulmonary toxicants. Previous studies indicate that prior exposure to atmospheric oxidant pollutants such as ozone may significantly alter the response to other pollutants, such as 1-nitronaphthalene (1-NN) . 1-NN, a component of the particulate exhaust from diesel engines, has been found at low concentrations in ambient air. Using a metabolomic approach, we investigated inflammatory responses in arachidonic and linoleic acid biochemical cascades (35 metabolites) and the expression of 19 cytokines/chemokines at three time points (2, 6, and 24 hr) following exposure to 1-NN with and without prior long-term O3 exposure. Long-term O3 exposure is associated with biochemical changes that have been shown to render the lung resistant to further O3 exposure. This study indicates that airways of O3-tolerant rats exhibited a low level of chronic inflammation, rendering the lungs more susceptible to other environmental pollutants such as 1-NN. Specifically, a 12.5-mg/kg dose of 1-NN to O3-tolerant rats produced significantly higher levels of cysteinyl-leukotrienes in bronchiolar lavage fluid even when compared to a 50-mg/kg dose of 1-NN in rats exposed to filtered air. Collectively, these results indicate that the combination of exposures as encountered in polluted ambient air are considerably more injurious to the lung than would be anticipated from previous studies employing single exposures. The observed synergism between O3 and 1-NN may be causally related to a shift in a T-helper 1 to T-helper 2 immune response in the airways.
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Affiliation(s)
| | - Åsa M. Wheelock
- Department of Molecular Biosciences-School of Veterinary Medicine, University of California, Davis, California, USA
| | | | - Dexter Morin
- Department of Molecular Biosciences-School of Veterinary Medicine, University of California, Davis, California, USA
| | - Bruce D. Hammock
- Department of Entomology
- Cancer Research Center and
- Address correspondence to B.D. Hammock, Department of Entomology, One Shields Ave., University of California Davis, CA 95616 USA. Telephone: (530) 752-7519. Fax: (530) 752-1537. E-mail:
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29
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Troncy E, Hubert B, Pang D, Taha R, Gauvin D, Beauchamp G, Veldhuizen RAW, Blaise GA. Pre-emptive and continuous inhaled NO counteracts the cardiopulmonary consequences of extracorporeal circulation in a pig model. Nitric Oxide 2006; 14:261-71. [PMID: 16545587 DOI: 10.1016/j.niox.2006.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 01/05/2006] [Accepted: 01/16/2006] [Indexed: 11/15/2022]
Abstract
Cardiopulmonary bypass (CPB) activates a systemic inflammatory response characterized clinically by alterations in cardiovascular and pulmonary function. The aim of this study was to measure the cardiopulmonary consequences in sham-operated pigs, and in animals subjected to CPB in the presence or absence of lipopolysaccharide (LPS). We also investigated, if the perioperative administration of inhaled NO exerts significant cardiopulmonary effects in an anaesthetized and mechanically ventilated pig model of extracorporeal circulation. Thirty pigs were randomized into six equal groups (sham; sham+INO; CPB; CPB+INO; CPB+LPS; CPB+LPS+INO) and subjected to anaesthesia with mechanical ventilation for up to 24h. We found that CPB+LPS group has the highest degree of lung injury. We also demonstrated that there was a significant difference on the cardiovascular parameters (heart rate, central venous pressure, stroke volume index, and mean systemic arterial blood pressure) between the CPB groups and the sham groups. The deteriorated lung mechanics was associated with a decrease in active subfraction of surfactant (LA) with time during the procedure (P=0.0003), on which inhaled NO had only an initial beneficial effect. In our model, inhaled NO had no long-term beneficial effect on lung mechanics and surfactant homeostasis despite improving lung haemodynamics, inflammation, and oxygenation. We conclude from this study that the use of pre-emptive and continuous inhaled NO therapy has protective and safe effects against lung ischemia/reperfusion associated with CPB.
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Affiliation(s)
- Eric Troncy
- Unit of Anaesthesiology/Pharmacology, Department of Veterinary Biomedicine, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, Que., Canada
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Rodríguez-Capote K, Manzanares D, Haines T, Possmayer F. Reactive oxygen species inactivation of surfactant involves structural and functional alterations to surfactant proteins SP-B and SP-C. Biophys J 2006; 90:2808-21. [PMID: 16443649 PMCID: PMC1414557 DOI: 10.1529/biophysj.105.073106] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Exposing bovine lipid extract surfactant (BLES), a clinical surfactant, to reactive oxygen species arising from hypochlorous acid or the Fenton reaction resulted in an increase in lipid (conjugated dienes, lipid aldehydes) and protein (carbonyls) oxidation products and a reduction in surface activity. Experiments where oxidized phospholipids (PL) were mixed with BLES demonstrated that this addition hampered BLES biophysical activity. However the effects were only moderately greater than with control PL. These results imply a critical role for protein oxidation. BLES oxidation by either method resulted in alterations in surfactant proteins SP-B and SP-C, as evidenced by altered Coomassie blue and silver staining. Western blot analyses showed depressed reactivity with specific antibodies. Oxidized SP-C showed decreased palmitoylation. Reconstitution experiments employing PL, SP-B, and SP-C isolated from control or oxidized BLES demonstrated that protein oxidation was more deleterious than lipid oxidation. Furthermore, addition of control SP-B can improve samples containing oxidized SP-C, but not vice versa. We conclude that surfactant oxidation arising from reactive oxygen species generated by air pollution or leukocytes interferes with surfactant function through oxidation of surfactant PL and proteins, but that protein oxidation, in particular SP-B modification, produces the major deleterious effects.
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Affiliation(s)
- Karina Rodríguez-Capote
- Department of Obstetrics/Gynaecology, Canadian Institutes of Health Research Group in Fetal and Neonatal Health and Development, University of Western Ontario, London, Ontario, Canada
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Manzer R, Wang J, Nishina K, McConville G, Mason RJ. Alveolar epithelial cells secrete chemokines in response to IL-1beta and lipopolysaccharide but not to ozone. Am J Respir Cell Mol Biol 2005; 34:158-66. [PMID: 16239643 PMCID: PMC2644180 DOI: 10.1165/rcmb.2005-0205oc] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Ozone exposure produces acute inflammation and neutrophil influx in the distal lung. Alveolar epithelial cells cover a large surface area, secrete chemokines, and may initiate or modify the inflammatory response. The effect of ozone on chemokine production by these cells has not been defined. Isolated rat type II cells were cultured in different conditions to express the morphologic appearance and biochemical markers for the type I and the type II cell phenotypes. These cells were exposed to ozone at an air/liquid interface. The type I-like cells were more susceptible to injury than the type II cells and showed signs of injury at exposure levels of 100 ppb ozone for 60 min. Both phenotypes showed evidence of lipid peroxidation after ozone exposure as measured by 8-isoprostane production, but neither phenotype secreted increased amounts of MIP-2 (CXCL3), CINC-1 (CXCL1), or MCP-1 (CCL2) in response to ozone. Both cell phenotypes secreted MIP-2 and MCP-1 in response to IL-1beta or lipopolysaccharide, but there was no priming or synergy with ozone. It is likely that the inflammatory response to ozone in the alveolar compartment is not due to the direct effect of ozone on epithelial cells.
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Affiliation(s)
- Rizwan Manzer
- Department of Medicine, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206, USA
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32
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Janic B, Umstead TM, Phelps DS, Floros J. Modulatory effects of ozone on THP-1 cells in response to SP-A stimulation. Am J Physiol Lung Cell Mol Physiol 2004; 288:L317-25. [PMID: 15466251 DOI: 10.1152/ajplung.00125.2004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Ozone (O(3)), a major component of air pollution and a strong oxidizing agent, can lead to lung injury associated with edema, inflammation, and epithelial cell damage. The effects of O(3) on pulmonary immune cells have been studied in various in vivo and in vitro systems. We have shown previously that O(3) exposure of surfactant protein (SP)-A decreases its ability to modulate proinflammatory cytokine production by cells of monocyte/macrophage lineage (THP-1 cells). In this report, we exposed THP-1 cells and/or native SP-A obtained from bronchoalveolar lavage of patients with alveolar proteinosis to O(3) and studied cytokine production and NF-kappaB signaling. The results showed 1) exposure of THP-1 cells to O(3) significantly decreased their ability to express TNF-alpha in response to SP-A; TNF-alpha production, under these conditions, was still significantly higher than basal (unstimulated) levels in filtered air-exposed THP-1 cells; 2) exposure of both THP-1 cells and SP-A to O(3) did not result in any significant differences in TNF-alpha expression compared with basal levels; 3) O(3) exposure of SP-A resulted in a decreased ability of SP-A to activate the NF-kappaB pathway, as assessed by the lack of significant increase and decrease of the nuclear p65 subunit of NF-kappaB and cytoplasmic IkappaBalpha, respectively; and 4) O(3) exposure of THP-1 cells resulted in a decrease in SP-A-mediated THP-1 cell responsiveness, which did not seem to be mediated via the classic NF-kappaB pathway. These findings indicate that O(3) exposure may mediate its effect on macrophage function both directly and indirectly (via SP-A oxidation) and by involving different mechanisms.
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Affiliation(s)
- Branislava Janic
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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Zenri H, Rodriquez-Capote K, McCaig L, Yao LJ, Brackenbury A, Possmayer F, Veldhuizen R, Lewis J. Hyperoxia exposure impairs surfactant function and metabolism. Crit Care Med 2004; 32:1155-60. [PMID: 15190966 DOI: 10.1097/01.ccm.0000126264.00551.c8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the effects of hyperoxia exposure on lung function and the endogenous surfactant system in spontaneously breathing adult rats. DESIGN Analysis of the pulmonary surfactant system isolated from adult rats following exposure to > 90% oxygen or room air for 48 or 72 hrs. SETTING A basic science research laboratory in a university setting. SUBJECTS Sixty pathogen-free Sprague-Dawley rats. INTERVENTIONS Exposure to > 90% oxygen for 72 hrs. MEASUREMENTS AND MAIN RESULTS Exposure to > 90% oxygen for 72 hrs resulted in significant lung dysfunction and an increase in neutrophils and total protein concentrations within the airspace compared with animals exposed to room air or 48 hrs of 90% oxygen exposure. Total alveolar surfactant and large aggregate pool sizes were increased after 72 hrs of hyperoxia compared with the other groups, and there was evidence of lipid peroxidation within these large aggregate subtractions. The biophysical function of large aggregate isolated from 72-hr hyperoxia-exposed animals was also impaired and converted into small aggregate forms faster than large aggregate from normoxia-exposed animals when assessed using in vitro surface area cycling techniques. CONCLUSIONS Oxidative stress on the endogenous surfactant system may represent an important mechanism contributing to the surfactant dysfunction and abnormal surfactant metabolism associated with hyperoxia-induced lung injury.
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Affiliation(s)
- Hiromi Zenri
- Department of Medicine, Lawson Health Research Institute, St. Joseph's Health Centre, The University of Western Ontario, London, Ontario, Canada
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Schmidt R, Schäfer C, Luboeinski T, Löckinger A, Hermle G, Grimminger F, Seeger W, Ghofrani A, Schütte H, Günther A. Increase in alveolar antioxidant levels in hyperoxic and anoxic ventilated rabbit lungs during ischemia. Free Radic Biol Med 2004; 36:78-89. [PMID: 14732292 DOI: 10.1016/j.freeradbiomed.2003.10.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2003] [Revised: 10/16/2003] [Accepted: 10/27/2003] [Indexed: 10/26/2022]
Abstract
Increases in free radicals are believed to play a central role in the development of pulmonary ischemia/reperfusion (I-R) injury, leading to microvascular leakage and deterioration of pulmonary surfactant. Continued ventilation during ischemia offers significant protection against I-R injury, but the impact of alveolar oxygen supply both on lung injury and on radical generation is still unclear. We investigated the influence of hyperoxic (95% O2) and anoxic (0% O2) ventilation during ischemia on alveolar antioxidant status and surfactant properties in isolated rabbit lungs. Normoxic and hyperoxic ventilated, buffer-perfused lungs (n = 5 or 6) and native lungs (n = 6) served as controls. As compared with controls, biophysical and biochemical surfactant properties were not altered in anoxic as well as hyperoxic ventilated ischemic (2, 3, and 4 h) lungs. Assessment of several antioxidants (reduced glutathione (GSH), alpha-tocopherol (vitamin E), retinol (vitamin A), ascorbic acid (vitamin C), uric acid, and plasmalogens (1-O-alkenyl-2-acyl-phospholipids)) in bronchoalveolar lavage fluid (BALF) revealed a significant increase in antioxidant compounds under anoxic and hyperoxic ventilation, with maximum levels occuring after 3 h of ischemia. For example, GSH increased to 5.1 +/- 0.8 microM (mean +/- SE, p <.001) after 3 h of anoxic ventilated ischemia and to 2.7 +/- 0.2 microM (p <.01) after hyperoxic ventilated ischemia compared with native controls (1.3 +/- 0.2 microM), but did not significantly change under anoxic and hyperoxic ventilation alone. In parallel, under ischemic conditions, oxidized glutathione (GSSG) increased during hyperoxic (3 h: 0.81 +/- 0.04 microM, p <.001), but remained unchanged during anoxic (3 h: 0.31 +/- 0.04 microM) ventilation compared with native controls (0.22 +/- 0.02 microM), whereas F2-isoprostanes were elevated under both hyperoxic (3 h: 63 +/- 15 pM, p <.01) and anoxic (3 h: 50 +/- 9 pM, p <.01) ventilation compared with native controls (16 +/- 4 pM). We conclude that oxidative stress is increased in the lung alveolar lining layer during ischemia, during both anoxic and hyperoxic ventilation. This is paralleled by an increase rather than a decrease in alveolar antioxidant levels, suggested to reflect an adaptive response to oxidative stress during ischemia.
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Affiliation(s)
- Reinhold Schmidt
- Medizinische Klinik II, Zentrum für Innere Medizin, Justus-Liebig-University, Giessen, Germany.
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35
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Huang W, Wang G, Phelps DS, Al-Mondhiry H, Floros J. Human SP-A genetic variants and bleomycin-induced cytokine production by THP-1 cells: effect of ozone-induced SP-A oxidation. Am J Physiol Lung Cell Mol Physiol 2003; 286:L546-53. [PMID: 14617519 DOI: 10.1152/ajplung.00267.2003] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Surfactant protein A (SP-A) plays a role in innate host defense. Human SP-A is encoded by two functional genes (SP-A1 and SP-A2), and several alleles have been characterized for each gene. We assessed the effect of in vitro expressed human SP-A genetic variants, on TNF-alpha and IL-8 production by THP-1 cells in the presence of bleomycin, either before or after ozone-induced oxidation of the variants. The oligomerization of SP-A variants was also examined. We found 1) cytokine levels induced by SP-A2 (1A, 1A(0)) were significantly higher than those by SP-A1 (6A(2), 6A(4)) in the presence of bleomycin. 2) In the presence of bleomycin, ozone-induced oxidation significantly decreased the ability of 1A and 1A/6A(4), but not of 6A(4), to stimulate TNF-alpha production. 3) The synergistic effect of bleomycin/SP-A, either before or after oxidation, can be inhibited to the level of bleomycin alone by surfactant lipids. 4) Differences in oligomerization were also observed between SP-A1 and SP-A2. The results indicate that differences among SP-A variants may partly explain the individual variability of pulmonary complications observed during bleomycin chemotherapy and/or in an environment that may promote protein oxidation.
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Affiliation(s)
- Weixiong Huang
- Departments of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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Vazquez de Lara LG, Umstead TM, Davis SE, Phelps DS. Surfactant protein A increases matrix metalloproteinase-9 production by THP-1 cells. Am J Physiol Lung Cell Mol Physiol 2003; 285:L899-906. [PMID: 12842807 DOI: 10.1152/ajplung.00082.2003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Matrix metalloproteinase (MMP)-9 from alveolar macrophages is a major source of elastolytic activity in the lung. It is increased in the bronchoalveolar lavage fluid of patients with emphysema. Although the importance of macrophage-derived elastolytic activity in the pathogenesis of emphysema is well established, questions remain about MMP-9 regulation and activity. Because surfactant protein A (SP-A) is capable of modulating other functions of human monocytic cells, we hypothesized that SP-A may regulate MMP-9 expression. Vitamin D3-differentiated THP-1 cells and peripheral blood mononuclear cells were stimulated in vitro with several concentrations of SP-A for different incubation times. MMP-9 mRNA expression was measured by dot-blot analysis, gelatinolytic activity in the medium was determined by gel zymography, protein expression was determined by ELISA, and a specific MMP-9 activity assay was used to measure the state of activation of this enzyme in the cell supernatants. SP-A induced the expression of MMP-9 in both cell types, the effect was time and dose dependent, and MMP-9 was released in its zymogen form. On the basis of results of neutralizing antibody studies, we believe that SP-A action is mediated through Toll-like receptor-2. Even though the biological meaning of these findings remains to be elucidated, these observations suggest the presence of a novel, locally controlled mechanism by which MMP-9 levels may be regulated in alveolar macrophages. We speculate that SP-A may influence the protease/antiprotease balance in the lungs of patients with quantitative and/or qualitative changes in surfactant constituents favoring an abnormal breakdown of extracellular matrix components.
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Affiliation(s)
- Luis G Vazquez de Lara
- Dept. of Pediatrics, Pennsylvania State Univ. College of Medicine, PO Box 850, Hershey, PA 17033, USA.
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Rodriguez Capote K, McCormack FX, Possmayer F. Pulmonary surfactant protein-A (SP-A) restores the surface properties of surfactant after oxidation by a mechanism that requires the Cys6 interchain disulfide bond and the phospholipid binding domain. J Biol Chem 2003; 278:20461-74. [PMID: 12600986 DOI: 10.1074/jbc.m212697200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Reactive oxygen species produced by activated leuko-cytes in the alveolar epithelial lining fluid have been implicated in the inactivation of pulmonary surfactant and the impairment of lung function. Oxidation of bovine lipid extract surfactant (BLES), a therapeutic surfactant, with hypochlorous acid (H-BLES) or the Fenton reaction (F-BLES) led to temporary increases in conjugated dienes and formation of malondialdehyde and 4-hydroxy-2-nonenal. Electrospray ionization mass spectrometry revealed the appearance of lipid hydroperoxides, peroxides, lysophospholipids, and free fatty acids. Captive bubble tensiometer studies of H-BLES demonstrated prolonged adsorption times, film instability at low surface tensions during film compression, and reduced respreadability during film expansion. F-BLES exhibited prolonged adsorption times, a marked effect on increasing compressibility during compression, and a lesser effect on reducing respreadability on expansion. Addition of native bovine or rat surfactant-associated protein A (SP-A) reversed the effects of oxidation on surfactant biophysical properties. Studies using mutant recombinant rat SP-As indicated that an intact carbohydrate recognition domain and disulfide-dependent oligomeric assembly are critical for these effects, but the collagen-like region is not required. We conclude that SP-A can reverse the detrimental effects of surfactant oxidation on the biophysical properties of surfactant, by a mechanism that is dependent on interchain disulfide bond formation and the C-terminal domains of the protein.
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Affiliation(s)
- Karina Rodriguez Capote
- Departments of Obstetrics/Gynecology and Biochemistry, Canadian Institutes of Health Research Group in Fetal and Neonatal Health and Development, University of Western Ontario, London N6A 5A5, Canada
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Janic B, Umstead TM, Phelps DS, Floros J. An in vitro cell model system for the study of the effects of ozone and other gaseous agents on phagocytic cells. J Immunol Methods 2003; 272:125-34. [PMID: 12505718 DOI: 10.1016/s0022-1759(02)00440-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ozone (O(3)), a major component of air pollution and a very strong oxidizing agent, can lead to lung injury associated with edema, inflammation, and epithelial cell damage. The ozone effects on pulmonary immune cells have been studied by various in vivo and in vitro systems. In this report, we characterized a model system of cells of monocyte/macrophage lineage (THP-1 cells) exposed to ozone in vitro by studying cell viability and cell surface marker expression. THP-1 cells exposed to ozone in concentrations ranging from 0.1 to 0.5 ppm for 1 h were analyzed for cell viability and apoptosis (Annexin V/7-Amino-actinomycin D (7-AAD) flow cytometric assay) either immediately after ozone exposure or at later time points. This analysis showed absence of apoptosis and a small decrease in cell viability (5-17%) in ozone-exposed THP-1 cells. Cell surface protein expression (CD14 and CD11b) did not change following ozone exposure, but the effect of lipopolysaccharride (LPS) on TNF-alpha production following ozone exposure changed compared to filtered air/LPS-exposed cells. These findings indicate that this in vitro ozone cell-exposure system may be used in studies where the effects of various agents (physiological and non-physiological) on phagocytic cells can be analyzed. This model system offers conditions where the experimental results are not due to cell death, but rather due to the effects of ozone and/or agents under investigation.
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Affiliation(s)
- Branislava Janic
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey 17033, USA
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39
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Haddad JJ. Oxygen homeostasis, thiol equilibrium and redox regulation of signalling transcription factors in the alveolar epithelium. Cell Signal 2002; 14:799-810. [PMID: 12135701 DOI: 10.1016/s0898-6568(02)00022-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
There is growing evidence linking the pathophysiology of lung disease to an imbalance state of reduction-oxidation (redox) equilibrium. The therapeutic potential of glutathione, an ubiquitous sulfhydryl thiol, and its immunopharmacological properties in the airway epithelium bears clinical consequences for the paediatric treatment of respiratory distress (RD). Dynamic variation in alveolar pO(2) and its effect on redox state may impose a direct role in modulating the pattern of gene expression in lung tissues and, accordingly, could be pivotal in determining cellular fate under these conditions. Hypoxia-inducible factor-1alpha (HIF-1alpha) and nuclear factor-kappaB (NF-kappaB) are redox-sensitive transcription factors of particular importance because their differential activation by reducing and oxidizing signals, respectively, regulate the expression/suppression of O(2)-responsive genes. The regulation of these transcription factors, therefore, which is redox sensitive, is consistent with their roles in coordinating adaptive homeostatic responses to oxidative stress. Functionally, the relationship between O(2), glutathione biosynthesis and transcription factor activity bears typical implications for the pattern of cellular survivorship and alveolarization on exposure to O(2)-linked stresses. In this review, I discuss (1) the HIF-1alpha/NF-kappaB responsiveness to dynamic changes in pO(2) characteristic of the transition period from placental to pulmonary-based respiration, (2) the capacity of the alveolar epithelium to engage in glutathione biosynthesis and redox shuttling, effectively forming a feedback mechanism governing gene expression, (3) the restitution of antioxidant/prooxidant equilibrium following oxidative challenge and its dependency on the adaptive coordination of responses between redox-associated signalling pathways controlling apoptosis and genetic regulatory factors and (4) a likely association between oxidative stress and the evolution of an inflammatory signal through the pleiotropic O(2)-sensitive cytokines.
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Affiliation(s)
- John J Haddad
- Neuroscience Research Laboratory, Department of Anesthesia and Perioperative Care, University of California at San Francisco, Medical Sciences Building S-261, San Francisco, CA 94143-0542, USA.
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Uhlson C, Harrison K, Allen CB, Ahmad S, White CW, Murphy RC. Oxidized phospholipids derived from ozone-treated lung surfactant extract reduce macrophage and epithelial cell viability. Chem Res Toxicol 2002; 15:896-906. [PMID: 12118999 DOI: 10.1021/tx010183i] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ozone is known to be a highly toxic gas present in the urban air which exerts its effect on pulmonary tissue through its facile chemical reactions with target molecules in the airway. One of the first barriers encountered by ozone is epithelial lining fluid which contains pulmonary surfactant rich in glycerophosphocholine lipids. The reaction of ozone with calf lung surfactant extract was found to result in the production of 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (16:0a/9-al-GPCho) as an expected product of the ozonolysis of abundant unsaturated phospholipids containing unsaturated fatty acyl groups with a double bond at carbon-9. This oxidized phospholipid was identified as a biologically active product in that it reduced elicited macrophage viability by necrosis with an ED(50) of 6 microM. Further studies of the biological activity of 16:0a/9-al-GPCho revealed that concentrations from 100 to 200 nM initiated apoptosis in pulmonary epithelial-like A549 cells as assessed by TUNEL staining, nuclear size, and caspase-3 activation with loss of viability indicated by reduction of mitochondrial dehydrogenase activity. The release of IL-8, a neutrophil chemokine, from A549 cells was also stimulated by 50-100 nM 16:0a/9-al-GPCho. Exposure of calf lung surfactant to low levels of ozone (62.5, 125, and 250 ppb) for various time periods from 2 to 48 h in a feedback-regulated ozone exposure chamber resulted in a dose- and time-dependent increase in the formation of 16:0a/9-al-GPCho as measured by a specific and sensitive LC/MS/MS assay. The quantity of this biologically active chain-shortened glycerophosphocholine lipid generated even at 125 ppb ozone for 2-4 h (50-100 nM) was consistent with this product mediating the toxic effects of ozone on cells in contact with surfactant.
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Affiliation(s)
- Charis Uhlson
- Division of Cell Biology, Department of Pediatrics, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, Colorado 80206, USA
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41
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Johnston SD, Starrs AP, Daniels CB, Orgeig S. Ontogeny of the pulmonary surfactant and antioxidant enzyme systems in the viviparous lizard, Tiliqua rugosa. Physiol Biochem Zool 2002; 75:260-72. [PMID: 12177829 DOI: 10.1086/341999] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2002] [Indexed: 11/03/2022]
Abstract
The antioxidant enzyme (AOE) system protects the lung from oxidative damage. The pulmonary surfactant (PS) system lowers the interfacial pressure within the lung, improving lung compliance and aiding lung clearance. In mammals, the AOE and PS systems develop in tandem during the final 10%-20% of gestation. Here, we investigated the development of these systems in the viviparous skink, Tiliqua rugosa. The content of total phospholipid (PL), disaturated phospholipid (DSP), and cholesterol (Chol) increased in lung washings from foetal lizards with advancing gestational age. Similarly, the relative saturation of the PLs increased throughout gestation, with mid-stage 40 foetuses having a DSP/PL equivalent to newborns and adults. Maternal lizards had significantly less total PL, DSP, and Chol than nongravid and newborn lizards; however, the relative composition did not differ from nongravid animals. This presumably results from compression of the lungs under the bulk of the developing foetus. The Chol/PL and Chol/DSP ratios declined early in development such that mid-stage 40 embryos had comparable ratios to both newborns and adults. Thus, it appears that the PS system matures in a similar manner in skinks and in mammals. However, the composition of surfactant is complete some weeks before parturition, probably to enable improved survivorship of the precocial young in the event of premature birth. Unlike the surfactant lipids, the AOEs, catalase, superoxide dismutase, and glutathione peroxidase did not differ appreciably throughout gestation. It appears therefore that like the surfactant lipids the AOE system is in readiness for air breathing throughout the latter stages of gestation, possibly in preparation for premature birth. Unlike mammals, the PS and AOE systems develop independently from one another.
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Affiliation(s)
- Sonya D Johnston
- Department of Physiology, University of Adelaide, Adelaide, South Australia 5005, Australia
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Ochs M, Fehrenbach H, Richter J. Ultrastructure of canine type II pneumocytes during hypothermic ischemia of the lung: a study by means of conventional and energy filtering transmission electron microscopy and stereology. ACTA ACUST UNITED AC 2001; 263:118-26. [PMID: 11360229 DOI: 10.1002/ar.1084] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Alterations in pulmonary surfactant have been reported to be associated with ischemia/reperfusion injury in experimental and clinical lung transplantation. It is unknown whether these alterations are due to damage to surfactant synthesizing type II pneumocytes during hypothermic ischemic storage. The aim of the present study was to examine the effects of hypothermic ischemic storage of the lung on canine type II pneumocytes by means of conventional (CTEM) and energy filtering TEM (EFTEM) and stereology. The lungs of 18 dogs were fixed for TEM immediately after cardiac arrest (6 double lungs) and after storage in Tutofusin at 4 degrees C for 20 min, 4 hr, 8 hr, and 12 hr (6 single lungs, respectively). Using a systematic uniform random sampling scheme, type II pneumocytes were analyzed qualitatively and stereologically. The relative phosphorus content of cell organelles, especially the surfactant containing lamellar bodies, was investigated by EFTEM. By CTEM, no major qualitative alterations could be observed in type II pneumocytes of the experimental groups. Stereologically, no significant changes in the volume densities or the volume-to-surface ratios of type II pneumocytes and their lamellar bodies were found. By EFTEM, the highest intracellular phosphorus signals were recorded over lamellar bodies in all experimental groups. No changes in the phosphorus signals were observed during ischemia. These results indicate that the ultrastructure of canine type II pneumocytes and their lamellar bodies is not affected by hypothermic ischemia of the lung up to 12 hr. Structural preservation of intracellular surfactant is possible during prolonged ischemic lung storage.
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Affiliation(s)
- M Ochs
- Department of Anatomy, Division of Electron Microscopy, Georg-August-University, Göttingen, Germany.
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43
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Fehrenbach H. Alveolar epithelial type II cell: defender of the alveolus revisited. Respir Res 2001; 2:33-46. [PMID: 11686863 PMCID: PMC59567 DOI: 10.1186/rr36] [Citation(s) in RCA: 519] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2000] [Revised: 12/05/2000] [Accepted: 12/06/2000] [Indexed: 01/13/2023] Open
Abstract
In 1977, Mason and Williams developed the concept of the alveolar epithelial type II (AE2) cell as a defender of the alveolus. It is well known that AE2 cells synthesise, secrete, and recycle all components of the surfactant that regulates alveolar surface tension in mammalian lungs. AE2 cells influence extracellular surfactant transformation by regulating, for example, pH and [Ca2+] of the hypophase. AE2 cells play various roles in alveolar fluid balance, coagulation/fibrinolysis, and host defence. AE2 cells proliferate, differentiate into AE1 cells, and remove apoptotic AE2 cells by phagocytosis, thus contributing to epithelial repair. AE2 cells may act as immunoregulatory cells. AE2 cells interact with resident and mobile cells, either directly by membrane contact or indirectly via cytokines/growth factors and their receptors, thus representing an integrative unit within the alveolus. Although most data support the concept, the controversy about the character of hyperplastic AE2 cells, reported to synthesise profibrotic factors, proscribes drawing a definite conclusion today.
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Affiliation(s)
- H Fehrenbach
- Institute of Pathology, University Clinics Carl Gustav Carus, Technical University of Dresden, Germany.
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Müller B, Hochscheid R, Seifart C, Barth PJ. alpha-tocopherol improves impaired physiology of rat type II pneumocytes isolated from experimentally injured lungs. Eur J Clin Invest 2000; 30:1018-26. [PMID: 11114965 DOI: 10.1046/j.1365-2362.2000.00730.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Oxidant stress delivered by nitrogen dioxide (NO2) inhalation impairs the function of extracellular surfactant as well as surfactant phospholipid metabolism in type II pneumocytes. Because protection against oxidant stress is important to normal lung function, the lung contains a variety of antioxidants, including vitamin E. Whether administration of this antioxidant during NO2 inhalation attenuates NO2-induced alterations in phospholipid metabolism in type II pneumocytes has not been studied. METHODS We exposed rats to identical NO2 body doses (720 p.p.m. x h) using continuous, intermittent, or repetitive protocols. During exposure periods, the animals received daily intramuscular injections of vitamin E (25 mg kg-1). We isolated type II pneumocytes from NO2-exposed rats and evaluated them for cell yield and viability, as well as for synthesis and secretion of phosphatidylcholine (PC) as measures of surfactant metabolism. RESULTS The yield of type II pneumocytes was significantly elevated from animals that had been exposed continuously to NO2 whereas in intermittently and repeatedly exposed rats, cell yield was similar to yield from control animals. Viability of the isolated cells was similar in controls and all NO2 exposure protocols. Vitamin E treatment of the NO2-exposed rats neither changed cell yield nor cell viability. Phospholipid de novo synthesis, as estimated by choline incorporation into PC, was increased most after continuous NO2 inhalation whereas in the other conditions there was only a slight increase. Vitamin E administration further increased phospholipid synthesis; this difference reached statistical significance only in the case of intermittent NO2 exposure. Secretion of phosphatidylcholine from type II cells was only reduced after continuous NO2 inhalation and administration of the antioxidant reduced the impairment. CONCLUSION Because vitamin E appears to preserve the ability of type II pneumocytes isolated from NO2-exposed rats to synthesize and secrete surfactant lipid, we conclude that administration of vitamin E may mitigate NO2-induced lung injury.
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Affiliation(s)
- B Müller
- Philipps University of Marburg, Marburg, Germany.
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Abstract
Highly standardized and controlled inhalation studies are required for hazard identification to make test results reproducible and comparable and to fulfill general regulatory requirements for the registration of new drugs, pesticides, or chemicals. Despite significant efforts, the results of inhalation studies have to be analyzed judiciously due to the great number of variables. These variables may be related to technical issues or to the specific features of the animal model. Although inhalation exposure of animals mimics human exposure best, ie, error-prone route-to-route extrapolations are not necessary, not all results obtained under such very rigorous test conditions may necessarily also occur under real-life exposure conditions. Attempts are often made to duplicate as closely as possible these real-life exposure conditions of humans in appropriate bioassays. However, this in turn might affect established baseline data, rendering the interpretation of new findings difficult. In addition, specific use patterns, eg, of inhalation pharmaceuticals or pesticide-containing consumer products, may impose test agent-specific constraints that challenge traditional approaches. Moreover, specific modes of action of the substance under investigation, the evaluation of specific endpoints, or the clarification of equivocal findings in common rodent species may require exposure paradigms or the use of animal species not commonly used in inhalation toxicology. However, particularly in inhalation toxicology, the choice of animal models for inhalation toxicity testing is usually based on guideline requirements and practical considerations, such as exposure technology, expediency, and previous experience rather than validity for use in human beings. Larger animal species, apart from the welfare aspects, may require larger inhalation chambers to accommodate the animals, but for technical reasons and the difficulty of generating homogeneous exposure atmospheres in such inhalation chambers, this may jeopardize the outcome of the study. Some of the many variables and possible artifacts likely to occur in animal inhalation studies are addressed in this paper.
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Affiliation(s)
- J Pauluhn
- Institute of Toxicology, Bayer AG, Wuppertal, Germany.
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Weng YH, Tatarov A, Bartos BP, Contag CH, Dennery PA. HO-1 expression in type II pneumocytes after transpulmonary gene delivery. Am J Physiol Lung Cell Mol Physiol 2000; 278:L1273-9. [PMID: 10835334 DOI: 10.1152/ajplung.2000.278.6.l1273] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Somatic cell gene transfer is a potentially useful strategy to alter lung function. However, achieving efficient transfer to the alveolar epithelium, especially in smaller animals, has not been demonstrated. In this study, the rat heme oxygenase-1 (HO-1) gene was delivered to the lungs of neonatal mice via transpulmonary injection. A bidirectional promoter construct coexpressing both HO-1 and a luciferase reporter gene was used so that in vivo gene expression patterns could be monitored in real time. HO-1 expression levels were also modulated with doxycycline and assessed in vivo with bioluminescent light transmitted through the tissues from the coregulated luciferase reporter. As a model of oxidative stress and HO-1-mediated protection, groups of animals were exposed to hyperoxia. After gene transfer, elevated levels of HO-1 were detected predominantly in alveolar type II cells by immunocytochemistry. With overexpression of HO-1, increased oxidative injury was observed. Furthermore, this model demonstrated a cell-specific effect of lung HO-1 overexpression in oxidative stress. Specific control of expression for therapeutic genes is possible in vivo. The transpulmonary approach may prove useful in targeting gene expression to cells of the alveolar epithelium or to circumscribed areas of the lung.
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Affiliation(s)
- Y H Weng
- Department of Pediatrics, Stanford University School of Medicine, Palo Alto, California 94304, USA
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Haddad JJ, Land SC. O(2)-evoked regulation of HIF-1alpha and NF-kappaB in perinatal lung epithelium requires glutathione biosynthesis. Am J Physiol Lung Cell Mol Physiol 2000; 278:L492-503. [PMID: 10710521 DOI: 10.1152/ajplung.2000.278.3.l492] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To test the genetic capacity of the perinatal lung to respond to O(2) shifts that coincide with the first respiratory movements, rat fetal alveolar type II (fATII) epithelial cells were cultured at fetal distal lung PO(2) (23 Torr) and then exposed to postnatal (23 --> 76 Torr; mild hyperoxic shift), moderate (23 --> 152 Torr; moderate hyperoxic shift), or severe (23 --> 722 Torr; severe hyperoxic shift) oxygenation. Nuclear abundance and consensus binding characteristics of hypoxia-inducible factor (HIF)-1alpha and nuclear factor (NF)-kappaB (Rel A/p65) plus glutathione biosynthetic capacity were determined. Maximal HIF-1alpha activation at 23 Torr was sustained over the postnatal shift in (Delta) PO(2) and was elevated in vivo throughout late gestation. NF-kappaB was activated by the acute postnatal DeltaPO(2) in fATII cells, becoming maximal with moderate and severe oxygenation in vitro and within 6 h of birth in vivo, declining thereafter. fATII cell and whole lung glutathione and GSH-to-GSSG ratio increased fourfold with a postnatal DeltaPO(2) and were matched by threefold activity increases in gamma-glutamylcysteine synthetase and glutathione synthase. GSH concentration depletion by L-buthionine-(S, R)-sulfoximine abrogated both HIF-1alpha and NF-kappaB activation, with HIF-1alpha showing a heightened sensitivity to GSH concentration. We conclude that O(2)-linked genetic regulation in perinatal lung epithelium is responsive to developmental changes in glutathione biosynthetic capacity.
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Affiliation(s)
- J J Haddad
- Oxygen Signalling Group, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
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Tokieda K, Iwamoto HS, Bachurski C, Wert SE, Hull WM, Ikeda K, Whitsett JA. Surfactant protein-B-deficient mice are susceptible to hyperoxic lung injury. Am J Respir Cell Mol Biol 1999; 21:463-72. [PMID: 10502556 DOI: 10.1165/ajrcmb.21.4.3436] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Surfactant protein-B (SP-B) is a small, hydrophobic peptide that plays a critical role in pulmonary function and surfactant homeostasis. To determine whether SP-B protects mice from oxygen-induced injury, heterozygous SP-B(+/-) gene-targeted mice and wild-type SP-B(+/+) littermates were exposed to hyperoxia (95% oxygen for 3 d) or room air. Although specific lung compliance in room air in SP-B(+/-) mice was slightly reduced as compared with that in SP-B(+/+) mice, it was reduced more markedly during hyperoxia (46% versus 25% decrease, respectively). The larger decrease in lung compliance in SP-B(+/-) mice was associated with increased severity of pulmonary edema, hemorrhage and inflammation, lung permeability and protein leakage into the alveolar space. Hyperoxia increased SP-B messenger RNA (mRNA) and total protein concentrations by 2-fold in SP-B(+/+) and SP-B(+/-) mice, but decreased the abundance of SP-B protein in lavage fluid relative to total protein only in SP-B(+/-) mice. Hyperoxia increased SP-B expression, but apparently not enough to maintain SP-B function and lung compliance in the presence of increased protein leakage in SP-B(+/-) mice. Increased alveolar-capillary leakage and relative deficiency of SP-B may therefore contribute to oxygen-induced pulmonary dysfunction in SP-B(+/-) mice. These data support the concept that SP-B plays an important protective role in the lung.
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Affiliation(s)
- K Tokieda
- Division of Neonatology and Pulmonary Biology, Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA
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Nielsen GD, Hougaard KS, Larsen ST, Hammer M, Wolkoff P, Clausen PA, Wilkins CK, Alarie Y. Acute airway effects of formaldehyde and ozone in BALB/c mice. Hum Exp Toxicol 1999; 18:400-9. [PMID: 10413245 DOI: 10.1191/096032799678840246] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
1. Concentration and time-effect relationships of formaldehyde and ozone on the airways were investigated in BALB/c mice. The effects were obtained by continuous monitoring of the respiratory rate, tidal volume, expiratory flow rate, time of inspiration, time of expiration, and respiratory patterns. 2. With concentrations up to 4 p.p.m., formaldehyde showed mainly sensory irritation effects of the upper airways that decrease the respiratory rate from a trigeminal reflex. The no-effect level (NOEL) was about 0.3 p.p.m. This value is close to the human NOEL, which is about 0.08 p.p.m. 3. Ozone caused rapid, shallow breathing in BALB/c mice. Later on, the respiratory rate decreased due to another vagal response that indicated an incipient lung oedema. The NOEL in mice was about 1 p.p.m. during 30 min of ozone exposure. No major effect occurs in resting humans at about 0.4 p.p.m. 4. Thus, the upper airway irritant, formaldehyde, and the deep lung irritant, ozone, showed the same types of respiratory effects in humans and in BALB/c mice. Also, the sensitivity was nearly identical. Continuous monitoring of respiratory effects in BALB/c mice, therefore, may be a valuable method for the study of effects of other environmental pollutants, which, however, should be confirmed in further studies.
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Affiliation(s)
- G D Nielsen
- National Institute of Occupational Health Denmark, Copenhagen
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50
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Embury SH, Mohandas N, Paszty C, Cooper P, Cheung AT. In vivo blood flow abnormalities in the transgenic knockout sickle cell mouse. J Clin Invest 1999; 103:915-20. [PMID: 10079113 PMCID: PMC408150 DOI: 10.1172/jci5977] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The accepted importance of circulatory impairment to sickle cell anemia remains to be verified by in vivo experimentation. Intravital microscopy studies of blood flow in patients are limited to circulations that can be viewed noninvasively and are restricted from deliberate perturbations of the circulation. Further knowledge of sickle blood flow abnormalities has awaited an animal model of human sickle cell disease. We compared blood flow in the mucosal-intestinal microvessels of normal mice with that in transgenic knockout sickle cell mice that have erythrocytes containing only human hemoglobin S and that exhibit a degree of hemolytic anemia and pathological complications similar to the human disease. In sickle cell mice, in addition to seeing blood flow abnormalities such as sludging in all microvessels, we detected decreased blood flow velocity in venules of all diameters. Flow responses to hyperoxia in both normal and sickle cell mice were dramatic, but opposite: Hyperoxia promptly slowed or halted flow in normal mice but markedly enhanced flow in sickle cell mice. Intravital microscopic studies of this murine model provide important insights into sickle cell blood flow abnormalities and suggest that this model can be used to evaluate the causes of abnormal flow and new approaches to therapy of sickle cell disease.
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Affiliation(s)
- S H Embury
- Division of Hematology and Department of Medicine, San Francisco General Hospital and the University of California-San Francisco, San Francisco, California 94110, USA.
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