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Li L, Xu M, Rowan SC, Howell K, Russell-Hallinan A, Donnelly SC, McLoughlin P, Baugh JA. The effects of genetic deletion of Macrophage migration inhibitory factor on the chronically hypoxic pulmonary circulation. Pulm Circ 2021; 10:2045894020941352. [PMID: 33447370 PMCID: PMC7780187 DOI: 10.1177/2045894020941352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/18/2020] [Indexed: 11/17/2022] Open
Abstract
While it is well established that the haemodynamic cause of hypoxic pulmonary hypertension is increased pulmonary vascular resistance, the molecular pathogenesis of the increased resistance remains incompletely understood. Macrophage migration inhibitory factor is a pleiotropic cytokine with endogenous tautomerase enzymatic activity as well as both intracellular and extracellular signalling functions. In several diseases, macrophage migration inhibitory factor has pro-inflammatory roles that are dependent upon signalling through the cell surface receptors CD74, CXCR2 and CXCR4. Macrophage migration inhibitory factor expression is increased in animal models of hypoxic pulmonary hypertension and macrophage migration inhibitory factor tautomerase inhibitors, which block some of the functions of macrophage migration inhibitory factor, and have been shown to attenuate hypoxic pulmonary hypertension in mice and monocrotaline-induced pulmonary hypertension in rats. However, because of the multiple pathways through which it acts, the integrated actions of macrophage migration inhibitory factor during the development of hypoxic pulmonary hypertension were unclear. We report here that isolated lungs from adult macrophage migration inhibitory factor knockout (MIF-/- ) mice maintained in normoxic conditions showed greater acute hypoxic vasoconstriction than the lungs of wild type mice (MIF+/+ ). Following exposure to hypoxia for three weeks, isolated lungs from MIF-/- mice had significantly higher pulmonary vascular resistance than those from MIF+/+ mice. The major mechanism underlying the greater increase in pulmonary vascular resistance in the hypoxic MIF-/- mice was reduction of the pulmonary vascular bed due to an impairment of the normal hypoxia-induced expansion of the alveolar capillary network. Taken together, these results demonstrate that macrophage migration inhibitory factor plays a central role in the development of the pulmonary vascular responses to chronic alveolar hypoxia.
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Affiliation(s)
- Lili Li
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Maojia Xu
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Simon C Rowan
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Katherine Howell
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Adam Russell-Hallinan
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Seamas C Donnelly
- Department of Medicine, Tallaght University Hospital & Trinity College Dublin, Dublin, Ireland
| | - Paul McLoughlin
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - John A Baugh
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
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Abstract
A growing body of evidence indicates that obesity is strongly and independently associated with adverse outcomes of COVID-19, including death. By combining emerging knowledge of the pathological processes involved in COVID-19 with insights into the mechanisms underlying the adverse health consequences of obesity, we present some hypotheses regarding the deleterious impact of obesity on the course of COVID-19. These hypotheses are testable and could guide therapeutic and preventive interventions. As obesity is now almost ubiquitous and no vaccine for COVID-19 is currently available, even a modest reduction in the impact of obesity on mortality and morbidity from this viral infection could have profound consequences for public health.
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Affiliation(s)
- Sam M Lockhart
- MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Stephen O'Rahilly
- MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science and NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 0QQ, UK
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3
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Ahrendt N, Steingrüber T, Rajces A, Lopez-Rodriguez E, Eisenberg T, Magnes C, Madeo F, Sedej S, Schmiedl A, Ochs M, Mühlfeld C, Schipke J. Spermidine supplementation and voluntary activity differentially affect obesity-related structural changes in the mouse lung. Am J Physiol Lung Cell Mol Physiol 2020; 319:L312-L324. [PMID: 32521164 DOI: 10.1152/ajplung.00423.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Obesity is associated with lung function impairment and respiratory diseases; however, the underlying pathophysiological mechanisms are still elusive, and therapeutic options are limited. This study examined the effects of prolonged excess fat intake on lung mechanics and microstructure and tested spermidine supplementation and physical activity as intervention strategies. C57BL/6N mice fed control diet (10% fat) or high-fat diet (HFD; 60% fat) were left untreated or were supplemented with 3 mM spermidine, had access to running wheels for voluntary activity, or a combination of both. After 30 wk, lung mechanics was assessed, and left lungs were analyzed by design-based stereology. HFD exerted minor effects on lung mechanics and resulted in higher body weight and elevated lung, air, and septal volumes. The number of alveoli was higher in HFD-fed animals. This was accompanied by an increase in epithelial, but not endothelial, surface area. Moreover, air-blood barrier and endothelium were significantly thicker. Neither treatment affected HFD-related body weights. Spermidine lowered lung volumes as well as endothelial and air-blood barrier thicknesses toward control levels and substantially increased the endothelial surface area under HFD. Activity resulted in decreased volumes of lung, septa, and septal compartments but did not affect vascular changes in HFD-fed mice. The combination treatment showed no additive effect. In conclusion, excess fat consumption induced alveolar capillary remodeling indicative of impaired perfusion and gas diffusion. Spermidine alleviated obesity-related endothelial alterations, indicating a beneficial effect, whereas physical activity reduced lung volumes apparently by other, possibly systemic effects.
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Affiliation(s)
- Nancy Ahrendt
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Tobias Steingrüber
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Alexandra Rajces
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Elena Lopez-Rodriguez
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany.,Institute of Vegetative Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Tobias Eisenberg
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Christoph Magnes
- Joanneum Research, HEALTH-Institute for Biomedicine and Health Sciences, Graz, Austria
| | - Frank Madeo
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Simon Sedej
- Department of Cardiology, Medical University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Andreas Schmiedl
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany.,Institute of Vegetative Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany
| | - Julia Schipke
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany
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4
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Brandsma J, Goss VM, Yang X, Bakke PS, Caruso M, Chanez P, Dahlén SE, Fowler SJ, Horvath I, Krug N, Montuschi P, Sanak M, Sandström T, Shaw DE, Chung KF, Singer F, Fleming LJ, Sousa AR, Pandis I, Bansal AT, Sterk PJ, Djukanović R, Postle AD. Lipid phenotyping of lung epithelial lining fluid in healthy human volunteers. Metabolomics 2018; 14:123. [PMID: 30830396 PMCID: PMC6153688 DOI: 10.1007/s11306-018-1412-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 08/12/2018] [Indexed: 01/20/2023]
Abstract
BACKGROUND Lung epithelial lining fluid (ELF)-sampled through sputum induction-is a medium rich in cells, proteins and lipids. However, despite its key role in maintaining lung function, homeostasis and defences, the composition and biology of ELF, especially in respect of lipids, remain incompletely understood. OBJECTIVES To characterise the induced sputum lipidome of healthy adult individuals, and to examine associations between different ELF lipid phenotypes and the demographic characteristics within the study cohort. METHODS Induced sputum samples were obtained from 41 healthy non-smoking adults, and their lipid compositions analysed using a combination of untargeted shotgun and liquid chromatography mass spectrometry methods. Topological data analysis (TDA) was used to group subjects with comparable sputum lipidomes in order to identify distinct ELF phenotypes. RESULTS The induced sputum lipidome was diverse, comprising a range of different molecular classes, including at least 75 glycerophospholipids, 13 sphingolipids, 5 sterol lipids and 12 neutral glycerolipids. TDA identified two distinct phenotypes differentiated by a higher total lipid content and specific enrichments of diacyl-glycerophosphocholines, -inositols and -glycerols in one group, with enrichments of sterols, glycolipids and sphingolipids in the other. Subjects presenting the lipid-rich ELF phenotype also had significantly higher BMI, but did not differ in respect of other demographic characteristics such as age or gender. CONCLUSIONS We provide the first evidence that the ELF lipidome varies significantly between healthy individuals and propose that such differences are related to weight status, highlighting the potential impact of (over)nutrition on lung lipid metabolism.
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Affiliation(s)
- Joost Brandsma
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
| | - Victoria M Goss
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Xian Yang
- Data Science Institute, Imperial College, London, UK
| | - Per S Bakke
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Massimo Caruso
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Pascal Chanez
- Department of Respiratory Diseases, Aix-Marseille University, Marseille, France
| | - Sven-Erik Dahlén
- Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden
| | - Stephen J Fowler
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, The University of Manchester, Manchester, UK
- Manchester Academic Health Science Centre, University Hospital of South Manchester, Manchester, UK
| | - Ildiko Horvath
- Department of Pulmonology, Semmelweis University, Budapest, Hungary
| | - Norbert Krug
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany
| | - Paolo Montuschi
- Department of Pharmacology, Faculty of Medicine, Catholic University of the Sacred Heart, Rome, Italy
| | - Marek Sanak
- Department of Medicine, Jagiellonian University, Krakow, Poland
| | - Thomas Sandström
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Dominick E Shaw
- Respiratory Research Unit, University of Nottingham, Nottingham, UK
| | - Kian Fan Chung
- National Heart and Lung Institute, Imperial College, London, UK
| | | | | | - Ana R Sousa
- Respiratory Therapy Unit, GlaxoSmithKline, London, UK
| | | | - Aruna T Bansal
- Acclarogen Ltd, St John's Innovation Centre, Cambridge, UK
| | - Peter J Sterk
- Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Ratko Djukanović
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- National Institute for Health Research Southampton Biomedical Research Centre, Southampton, UK
| | - Anthony D Postle
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
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5
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Dane DM, Cao K, Lu H, Yilmaz C, Dolan J, Thaler CD, Ravikumar P, Hammond KA, Hsia CCW. Acclimatization of low altitude-bred deer mice ( Peromyscus maniculatus) to high altitude. J Appl Physiol (1985) 2018; 125:1411-1423. [PMID: 30091664 DOI: 10.1152/japplphysiol.01036.2017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
A colony of deer mice subspecies ( Peromyscus maniculatus sonoriensis) native to high altitude (HA) has been maintained at sea level for 18-20 generations and remains genetically unchanged. To determine if these animals retain responsiveness to hypoxia, one group (9-11 wk old) was acclimated to HA (3,800 m) for 8 wk. Age-matched control animals were acclimated to a lower altitude (LA; 252 m). Maximal O2 uptake (V̇o2max) was measured at the respective altitudes. On a separate day, lung volume, diffusing capacity for carbon monoxide (DLCO), and pulmonary blood flow were measured under anesthesia using a rebreathing technique at two inspired O2 tensions. The HA-acclimated deer mice maintained a normal V̇o2max relative to LA baseline. Compared with LA control mice, antemortem lung volume was larger in HA mice in a manner dependent on alveolar O2 tension. Systemic hematocrit, pulmonary blood flow, and standardized DLCO did not differ significantly between groups. HA mice showed a higher postmortem alveolar-capillary hematocrit, larger alveolar ducts, and smaller distal conducting structures. In HA mice, absolute volumes of alveolar type I epithelia and endothelia were higher whereas that of interstitia was lower than in LA mice. These structural changes occurred without a net increase in whole-lung septal tissue-capillary volumes or surface areas. Thus, deer mice bred and raised to adulthood at LA retain phenotypic plasticity and adapt to HA without a decrement in V̇o2max via structural (enlarged airspaces, alveolar septal remodeling) and nonstructural (lung expansion under hypoxia) mechanisms and without an increase in systemic hematocrit or compensatory lung growth. NEW & NOTEWORTHY Deer mice ( Peromyscus maniculatus) are robust and very active mammals that are found across the North American continent. They are also highly adaptable to extreme environments. When introduced to high altitude they retain remarkable adaptive ability to the low-oxygen environment via lung expansion and remodeling of existing lung structure, thereby maintaining normal aerobic capacity without generating more red blood cells or additional lung tissue.
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Affiliation(s)
- D Merrill Dane
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Khoa Cao
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Hua Lu
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Cuneyt Yilmaz
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Jamie Dolan
- Department of Evolution, Ecology and Organismal Biology, University of California at Riverside , Riverside, California
| | - Catherine D Thaler
- Department of Evolution, Ecology and Organismal Biology, University of California at Riverside , Riverside, California
| | - Priya Ravikumar
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Kimberly A Hammond
- Department of Evolution, Ecology and Organismal Biology, University of California at Riverside , Riverside, California
| | - Connie C W Hsia
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
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6
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Persson PB, Bondke Persson A. Hunger, craving and appetite. Acta Physiol (Oxf) 2017; 221:3-5. [PMID: 28703474 DOI: 10.1111/apha.12917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P B Persson
- Corporate Member of Freie Universität Berlin, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin Institute of Health, Institute of Vegetative Physiology, Berlin, Germany
| | - A Bondke Persson
- Corporate Member of Freie Universität Berlin, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany
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7
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Persson PB, Bondke Persson A. Altitude sickness and altitude adaptation. Acta Physiol (Oxf) 2017; 220:303-306. [PMID: 28498559 DOI: 10.1111/apha.12894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- P. B. Persson
- Institute of Vegetative Physiology; Charité-Universitaetsmedizin Berlin; Berlin Germany
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8
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Rowan SC, Keane MP, Gaine S, McLoughlin P. Hypoxic pulmonary hypertension in chronic lung diseases: novel vasoconstrictor pathways. THE LANCET RESPIRATORY MEDICINE 2016; 4:225-36. [PMID: 26895650 DOI: 10.1016/s2213-2600(15)00517-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/03/2015] [Accepted: 12/07/2015] [Indexed: 11/29/2022]
Abstract
Pulmonary hypertension is a well recognised complication of chronic hypoxic lung diseases, which are among the most common causes of death and disability worldwide. Development of pulmonary hypertension independently predicts reduced life expectancy. In chronic obstructive pulmonary disease, long-term oxygen therapy ameliorates pulmonary hypertension and greatly improves survival, although the correction of alveolar hypoxia and pulmonary hypertension is only partial. Advances in understanding of the regulation of vascular smooth muscle tone show that chronic vasoconstriction plays a more important part in the pathogenesis of hypoxic pulmonary hypertension than previously thought, and that structural vascular changes contribute less. Trials of existing vasodilators show that pulmonary hypertension can be ameliorated and systemic oxygen delivery improved in carefully selected patients, although systemic hypotensive effects limit the doses used. Vasoconstrictor pathways that are selective for the pulmonary circulation can be blocked to reduce hypoxic pulmonary hypertension without causing systemic hypotension, and thus provide potential targets for novel therapeutic strategies.
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Affiliation(s)
- Simon C Rowan
- UCD School of Medicine, Conway Institute, Dublin, Ireland
| | - Michael P Keane
- UCD School of Medicine, Respiratory Medicine, St Vincent's University Hospital, Dublin, Ireland
| | - Seán Gaine
- National Pulmonary Hypertension Unit, Mater Misericordiae University Hospital, Dublin, Ireland
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9
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Affiliation(s)
- P. McLoughlin
- University College Dublin School of Medicine and Medical Sciences Conway Institute Dublin Ireland
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