1
|
Westwood J, Mayhook-Walker I, Simpkins C, Darby-Smith A, Morris D, Normando E. Retinal Vascular Changes in Response to Hypoxia: A High-Altitude Expedition Study. High Alt Med Biol 2024; 25:49-59. [PMID: 38011631 DOI: 10.1089/ham.2023.0084] [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] [Indexed: 11/29/2023] Open
Abstract
Westwood, Jessica, India Mayhook-Walker, Ciaran Simpkins, Andrew Darby-Smith, Dan Morris, and Eduardo Normando. Retinal vascular changes in response to hypoxia: a high-altitude expedition study. High Alt Med Biol. 25:49-59, 2024. Background: Increased tortuosity and engorgement of retinal vasculature are recognized physiological responses to hypoxia. This can lead to high-altitude retinopathy (HAR), but incidence reports are highly variable, and our understanding of the etiological mechanisms remains incomplete. This study quantitatively evaluated retinal vascular changes during an expedition to 4,167 m. Methods: Ten healthy participants summited Mount Toubkal, Morocco. Fundus images were taken predeparture, daily throughout the expedition, and 1 month postreturn. Diameter and tortuosity of four vessels were assessed, in addition to vessel density and features of HAR. Results: Significant (p ≤ 0.05) increases in tortuosity and diameter were observed in several vessels on high-altitude exposure days. There was a strong correlation between altitude and supratemporal retinal artery diameter on days 2, 3, and 6 of the expedition (r = 0.7707, 0.7951, 0.7401, respectively; p < 0.05). There was a significant increase in median vessel density from 6.7% at baseline to 10.0% on summit day. Notably there were no incidences of HAR. Conclusion: Physiological but not pathological changes were seen in this cohort, which gives insight into the state of the cerebral vasculature throughout this expedition. These results are likely attributable to relatively low altitude exposure, a conservative ascent profile, and the cohort's demographic. Future study must include daily retinal images at higher altitudes and take steps to mitigate environmental confounders. This study is relevant to altitude tourists, patients with diabetic retinopathy or retinal vein occlusion, and critically ill patients.
Collapse
Affiliation(s)
- Jessica Westwood
- Imperial College London Ophthalmology Research Group, Western Eye Hospital, London, United Kingdom
| | - India Mayhook-Walker
- Imperial College London Ophthalmology Research Group, Western Eye Hospital, London, United Kingdom
| | - Ciaran Simpkins
- Imperial College London Ophthalmology Research Group, Western Eye Hospital, London, United Kingdom
| | - Andrew Darby-Smith
- Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Dan Morris
- Cardiff Eye Unit, University Hospital of Wales, Cardiff, United Kingdom
| | - Eduardo Normando
- Imperial College London Ophthalmology Research Group, Western Eye Hospital, London, United Kingdom
| |
Collapse
|
2
|
Williamson JL, Linck EB, Bautista E, Smiley A, McGuire JA, Dudley R, Witt CC. Hummingbird blood traits track oxygen availability across space and time. Ecol Lett 2023. [PMID: 37178017 DOI: 10.1111/ele.14235] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/20/2023] [Accepted: 04/13/2023] [Indexed: 05/15/2023]
Abstract
Predictable trait variation across environments suggests shared adaptive responses via repeated genetic evolution, phenotypic plasticity or both. Matching of trait-environment associations at phylogenetic and individual scales implies consistency between these processes. Alternatively, mismatch implies that evolutionary divergence has changed the rules of trait-environment covariation. Here we tested whether species adaptation alters elevational variation in blood traits. We measured blood for 1217 Andean hummingbirds of 77 species across a 4600-m elevational gradient. Unexpectedly, elevational variation in haemoglobin concentration ([Hb]) was scale independent, suggesting that physics of gas exchange, rather than species differences, determines responses to changing oxygen pressure. However, mechanisms of [Hb] adjustment did show signals of species adaptation: Species at either low or high elevations adjusted cell size, whereas species at mid-elevations adjusted cell number. This elevational variation in red blood cell number versus size suggests that genetic adaptation to high altitude has changed how these traits respond to shifts in oxygen availability.
Collapse
Affiliation(s)
- Jessie L Williamson
- Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
- Cornell University Museum of Vertebrates, Cornell University, Ithaca, New York, USA
| | - Ethan B Linck
- Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Emil Bautista
- Centro de Ornitología y Biodiversidad (CORBIDI), Lima, Peru
| | - Ashley Smiley
- Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Jimmy A McGuire
- Museum of Vertebrate Zoology, University of California, Berkeley, California, USA
- Department of Integrative Biology, University of California, Berkeley, California, USA
| | - Robert Dudley
- Museum of Vertebrate Zoology, University of California, Berkeley, California, USA
- Department of Integrative Biology, University of California, Berkeley, California, USA
| | - Christopher C Witt
- Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, USA
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
| |
Collapse
|
3
|
Luo S, Ma X, Wu W, Lin S, Li M, Zhang Z, Zhu P, Song Z. Continuous Hypobaric Hypoxia may Promote Atherosclerosis Progression in Apolipoprotein E-deficient Mice. Int J Med Sci 2023; 20:849-857. [PMID: 37324194 PMCID: PMC10266041 DOI: 10.7150/ijms.78362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 04/07/2023] [Indexed: 06/17/2023] Open
Abstract
Background: Intermittent normobaric hypoxia can promote the progression of atherosclerotic plaques. However, the effect of continuous hypobaric hypoxia (CHH), which is a major feature of high-altitude environment, on atherosclerosis has not been investigated thoroughly. Materials and Methods: After eight weeks of high-cholesterol diet, 30 male ApoE-/- mice were randomly divided into control and CHH groups. Mice in the CHH group lived in a hypobaric chamber with an oxygen content of 10% and air pressure of 364 mmhg (equal to 5,800 m altitude above sea level) for 4 weeks, while mice in the control group lived in normoxia condition. Then all mice were euthanized and the atherosclerotic lesion size and plaque stability in the aortic root were assessed. Intraplaque angiogenesis was characterized by immunostaining of CD31 and endomucin, which are identified as specific markers of vascular endothelial cells. Immunohistochemistry and qRT-PCR were performed to measure inflammatory cytokines. Results: Four weeks of CHH exposure promoted the growth of atherosclerotic lesions (p=0.0017) and decreased the stability of atherosclerotic plaques. In CHH group, plaque smooth muscle cells and collagen contents decreased, while plaque macrophages and lipids contents increased significantly (p<0.001). The contents of CD31 (p=0.0379) and endomucin (p=0.0196) in the plaque was higher in the CHH group and correlated with angiogenesis progression. Further, the content of monocyte chemotactic protein-1 (p=0.0376) and matrix metalloproteinase-2 was significantly higher (p=0.0212) in the CHH group. Conclusions: CHH may accelerate atherosclerosis progression in ApoE-/- mice by promoting angiogenesis and inflammation.
Collapse
Affiliation(s)
- Shouming Luo
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xiaogen Ma
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Weiqiang Wu
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Shu Lin
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Group of Neuroendocrinology, Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China
| | - Mindian Li
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Zhihui Zhang
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Ping Zhu
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Zhiyuan Song
- Department of Cardiovascular Medicine, Center for Circadian Metabolism and Cardiovascular Disease, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| |
Collapse
|
4
|
Schäfer K, Tello K, Pak O, Richter M, Gierhardt M, Kwapiszewska G, Veith C, Fink L, Gall H, Hecker M, Kojonazarov B, Kraut S, Lo K, Wilhelm J, Grimminger F, Seeger W, Schermuly RT, Ghofrani HA, Zahner D, Gerstberger R, Weissmann N, Sydykov A, Sommer N. Decreased plasma levels of the brain-derived neurotrophic factor correlate with right heart congestion in pulmonary arterial hypertension. ERJ Open Res 2023; 9:00230-2022. [PMID: 36891080 PMCID: PMC9986749 DOI: 10.1183/23120541.00230-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 09/28/2022] [Indexed: 01/27/2023] Open
Abstract
Background The brain-derived neurotrophic factor (BDNF) may promote development of pulmonary hypertension and right ventricular (RV) failure. However, BDNF plasma levels were decreased in patients with left ventricular (LV) failure. Therefore, we investigated BDNF plasma levels in pulmonary hypertension patients and the role of BDNF in mouse models of pulmonary hypertension and isolated RV failure. Methods BDNF plasma levels were correlated to pulmonary hypertension in two patient cohorts, including either post- and pre-capillary pulmonary hypertension patients (first cohort) or only pre-capillary pulmonary hypertension patients (second cohort). In the second cohort, RV dimensions and load-independent function were determined by imaging and pressure-volume catheter measurements, respectively. For induction of isolated RV pressure overload, heterozygous Bdnf knockout (Bdnf+/- ) mice were subjected to pulmonary arterial banding (PAB). For induction of pulmonary hypertension, mice with inducible knockout of BDNF in smooth muscle cells (Bdnf/Smmhc knockout) were exposed to chronic hypoxia. Results Plasma BDNF levels were decreased in patients with pulmonary hypertension. Following adjustment for covariables, BDNF levels negatively correlated in both cohorts with central venous pressure. In the second cohort, BDNF levels additionally negatively correlated with RV dilatation. In animal models, BDNF downregulation attenuated RV dilatation in Bdnf+ /- mice after PAB or hypoxic Bdnf/Smmhc knockout mice, although they developed pulmonary hypertension to a similar extent. Conclusions Similar to LV failure, circulating levels of BDNF were decreased in pulmonary hypertension patients, and low BDNF levels were associated with right heart congestion. Decreased BDNF levels did not worsen RV dilatation in animal models, and thus, may be the consequence, but not the cause of RV dilatation.
Collapse
Affiliation(s)
- Katharina Schäfer
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,These authors contributed equally
| | - Khodr Tello
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,These authors contributed equally
| | - Oleg Pak
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,These authors contributed equally
| | - Manuel Richter
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Mareike Gierhardt
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Grazyna Kwapiszewska
- Ludwig Boltzmann Institute for Lung Vascular Research, Otto Loewi research Center, Medical University Graz, Graz, Austria.,Institute for Lung Health (ILH), Giessen, Germany
| | - Christine Veith
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Ludger Fink
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Henning Gall
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Matthias Hecker
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | | | - Simone Kraut
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Kevin Lo
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Jochen Wilhelm
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,Institute for Lung Health (ILH), Giessen, Germany
| | - Friedrich Grimminger
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Werner Seeger
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,Institute for Lung Health (ILH), Giessen, Germany
| | - Ralph T Schermuly
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Hossein A Ghofrani
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,Department of Medicine, Imperial College London, London, UK
| | - Daniel Zahner
- Central Laboratory Animal Facility, Justus-Liebig University, Giessen, Germany
| | - Rüdiger Gerstberger
- Institute of Veterinary Physiology and Biochemistry, Justus-Liebig University, Giessen, Germany
| | - Norbert Weissmann
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany
| | - Akylbek Sydykov
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,These authors contributed equally
| | - Natascha Sommer
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Excellence Cluster Cardio-Pulmonary Institute (CPI), Justus-Liebig University, Giessen, Germany.,These authors contributed equally
| |
Collapse
|
5
|
Doutreleau S, Ulliel-Roche M, Hancco I, Bailly S, Oberholzer L, Robach P, Brugniaux JV, Pichon A, Stauffer E, Perger E, Parati G, Verges S. Cardiac remodelling in the highest city in the world: effects of altitude and chronic mountain sickness. Eur J Prev Cardiol 2022; 29:2154-2162. [PMID: 35929776 DOI: 10.1093/eurjpc/zwac166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/20/2022] [Accepted: 08/03/2022] [Indexed: 01/11/2023]
Abstract
AIMS A unique Andean population lives in the highest city of the world (La Rinconada, 5100 m, Peru) and frequently develops a maladaptive syndrome, termed chronic mountain sickness (CMS). Both extreme altitude and CMS are a challenge for the cardiovascular system. This study aims to evaluate cardiac remodelling and pulmonary circulation at rest and during exercise in healthy and CMS highlanders. METHODS AND RESULTS Highlanders living permanently at 3800 m (n = 23) and 5100 m (n = 55) with (n = 38) or without CMS (n = 17) were compared with 18 healthy lowlanders. Rest and exercise echocardiography were performed to describe cardiac remodelling, pulmonary artery pressure (PAP), and pulmonary vascular resistance (PVR). Total blood volume (BV) and haemoglobin mass were determined in all people. With the increase in the altitude of residency, the right heart dilated with an impairment in right ventricle systolic function, while the left heart exhibited a progressive concentric remodelling with Grade I diastolic dysfunction but without systolic dysfunction. Those modifications were greater in moderate-severe CMS patients. The mean PAP was higher both at rest and during exercise in healthy highlanders at 5100 m. The moderate-severe CMS subjects had a higher PVR at rest and a larger increase in PAP during exercise. The right heart remodelling was correlated with PAP, total BV, and SpO2. CONCLUSION Healthy dwellers at 5100 m exhibit both right heart dilatation and left ventricle concentric remodelling with diastolic dysfunction. Those modifications are even more pronounced in moderate-severe CMS subjects and could represent the limit of the heart's adaptability before progression to heart failure.
Collapse
Affiliation(s)
- Stéphane Doutreleau
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Mathilde Ulliel-Roche
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Ivan Hancco
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Sébastien Bailly
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Laura Oberholzer
- The Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Paul Robach
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France.,National School for Mountain Sports, Site of the National School for Skiing and Mountaineering (ENSA), Chamonix, France
| | - Julien V Brugniaux
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Aurélien Pichon
- Laboratoire MOVE EA 6314, Faculté des Sciences du Sport, Université de Poitiers, Poitiers, France
| | - Emeric Stauffer
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Team 'Vascular Biology and Red Blood Cell', Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Elisa Perger
- Istituto Auxologico Italiano, IRCCS, Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy
| | - Gianfranco Parati
- Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Samuel Verges
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| |
Collapse
|
6
|
Malkmus K, Brosien M, Knoepp F, Schaffelhofer L, Grimminger F, Rummel C, Gudermann T, Dietrich A, Birnbaumer L, Weissmann N, Kraut S. Deletion of classical transient receptor potential 1, 3 and 6 alters pulmonary vasoconstriction in chronic hypoxia-induced pulmonary hypertension in mice. Front Physiol 2022; 13:1080875. [PMID: 36569761 PMCID: PMC9768328 DOI: 10.3389/fphys.2022.1080875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic hypoxia-induced pulmonary hypertension (CHPH) is a severe disease that is characterized by increased proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) leading to pulmonary vascular remodeling. The resulting increase in pulmonary vascular resistance (PVR) causes right ventricular hypertrophy and ultimately right heart failure. In addition, increased PVR can also be a consequence of hypoxic pulmonary vasoconstriction (HPV) under generalized hypoxia. Increased proliferation and migration of PASMCs are often associated with high intracellular Ca2+ concentration. Recent publications suggest that Ca2+-permeable nonselective classical transient receptor potential (TRPC) proteins-especially TRPC1 and 6-are crucially involved in acute and sustained hypoxic responses and the pathogenesis of CHPH. The aim of our study was to investigate whether the simultaneous deletion of TRPC proteins 1, 3 and 6 protects against CHPH-development and affects HPV in mice. We used a mouse model of chronic hypoxia as well as isolated, ventilated and perfused mouse lungs and PASMC cell cultures. Although right ventricular systolic pressure as well as echocardiographically assessed PVR and right ventricular wall thickness (RVWT) were lower in TRPC1, 3, 6-deficient mice, these changes were not related to a decreased degree of pulmonary vascular muscularization and a reduced proliferation of PASMCs. However, both acute and sustained HPV were almost absent in the TRPC1, 3, 6-deficient mice and their vasoconstrictor response upon KCl application was reduced. This was further validated by myographical experiments. Our data revealed that 1) TRPC1, 3, 6-deficient mice are partially protected against development of CHPH, 2) these changes may be caused by diminished HPV and not an altered pulmonary vascular remodeling.
Collapse
Affiliation(s)
- Kathrin Malkmus
- Cardiopulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Monika Brosien
- Cardiopulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Fenja Knoepp
- Cardiopulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Lisa Schaffelhofer
- Cardiopulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Friedrich Grimminger
- Cardiopulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Christoph Rummel
- Institute of Veterinary Physiology and Biochemistry, Justus-Liebig-University, Giessen, Germany
| | - Thomas Gudermann
- Walther Straub Institute for Pharmacology and Toxicology, Member of the DZL, Ludwig Maximilians University, Munich, Germany
| | - Alexander Dietrich
- Walther Straub Institute for Pharmacology and Toxicology, Member of the DZL, Ludwig Maximilians University, Munich, Germany
| | - Lutz Birnbaumer
- Institute of Biomedical Research (BIOMED), Catholic University of Argentina, Buenos Aires, Argentina,Laboratory of Signal Transduction, National Institute of Environmental Health Sciences (NIEHS), Durham, United States
| | - Norbert Weissmann
- Cardiopulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - Simone Kraut
- Cardiopulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany,*Correspondence: Simone Kraut,
| |
Collapse
|
7
|
Mean corpuscular haemoglobin concentration (MCHC): a new biomarker for high-altitude pulmonary edema in the Ecuadorian Andes. Sci Rep 2022; 12:20740. [PMID: 36456626 PMCID: PMC9715691 DOI: 10.1038/s41598-022-25040-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 11/23/2022] [Indexed: 12/05/2022] Open
Abstract
Ascent to high altitude (> 3000 m height above sea level or m.a.s.l) exposes people to hypobaric atmospheric pressure and hypoxemia, which provokes mountain sickness and whose symptoms vary from the mild acute mountain sickness to the life-threatening, high-altitude pulmonary edema (HAPE). This study analysed the risk factors underlying HAPE in dwellers and travellers of the Ecuadorian Andes after sojourning over 3000 m height. A group of HAPE patients (N = 58) was compared to a NO HAPE group (N = 713), through demographic (ethnicity, sex, and age), red blood cell parameters (erythrocytes counts, hematocrit, median corpuscular volume, median corpuscular haemoglobin, and median corpuscular haemoglobin concentration (MCHC)), altitude (threshold: 3000 m.a.s.l.), and health status (vital signs) variables. Analysis of Deviance for Generalised Linear Model Fits (logit regression) revealed patterns of significant associations. High-altitude dwellers, particularly children and elder people, were HAPE-prone, while women were more tolerant of HAPE than men. Interestingly, HAPE prevalence was strongly related to an increment of MCH. The residence at middle altitude was inversely related to the odds of suffering HAPE. Ethnicity did not have a significant influence in HAPE susceptibility. Elevated MCHC emerges like a blood adaptation of Andean highlanders to high altitude and biomarker of HAPE risk.
Collapse
|
8
|
Wang Z, Guo Q, Ma J, Cheng J, Zhao A, Li W, Wang R. Protective effect of salidroside on lung tissue in rats exposed rapidly to high altitude. Zhejiang Da Xue Xue Bao Yi Xue Ban 2022; 51:422-429. [PMID: 37202094 PMCID: PMC10264988 DOI: 10.3724/zdxbyxb-2022-0157] [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: 04/14/2022] [Accepted: 07/29/2022] [Indexed: 05/20/2023]
Abstract
OBJECTIVE To study the protective effect and mechanism of salidroside on lung tissue of rats exposed rapidly to high altitude. METHODS Thirty-six Wistar male rats were randomly divided into blank control group, model control group, Rhodiola rosea capsule (137 mg/kg) group, salidroside low-dose (14 mg/kg), medium-dose (28 mg/kg) and high-dose (56 mg/kg) groups, with 6 rats in each group. After 5 continuous days of drug administration in the plain lab, rats were rapidly moved to 4010 m plateau field lab. After exposure to hypoxia condition for 3 days the blood gas indexes were detected; the serum levels of inflammatory factors were measured by enzyme linked immunosorbent assay (ELISA); the oxidative stress index of lung tissue was measured; the pathological changes of lung tissue were observed by microscopy with hematoxylin and eosin (HE) staining; and the expression of occludin in lung tissues was determined by western blotting. RESULTS Compared with blank control group, arterial oxygen saturation (SaO 2), arterial oxygen partial pressure (PaO 2), blood pH, standard bicarbonate (SBC) and actual bicarbonate levels in model control group were significantly decreased, and hemoglobin level was significantly increased (all P<0.05). In the model control group, the contents of mast cell protease (MCP) 1, interleukin (IL)-6 and IL-1β were significantly increased, while the contents of interferon-γ were significantly decreased (all P<0.01). The contents of glutathione and total superoxide dismutase in the lung tissues of model control group were significantly decreased, while the content of malondialdehyde was significantly increased (all P<0.01). After Rhodiola rosea and salidroside were given, SaO 2, pH, hemoglobin, SBC and actual bicarbonate were improved compared with the model control group. Compared with the model control group, the Rhodiola rosea group and salidroside groups had different degrees of improvement in the contents of the above inflammatory factors and oxidative stress indexes, and the salidroside groups had better improvement in MCP-1 and IL-6 than the Rhodiola rosea group. HE staining showed that, after the administration of Rhodiola rosea capsules and salidroside at low, medium and high doses, the hypoxic injury was significantly improved, the cell wall gradually became thinner, and the alveolar wall gradually became complete. The expression of occludin in the model control group was lower than that in the blank control group ( P<0.05), while the expression of occludin in the salidroside high-dose group was significantly higher than that in the model control group ( P<0.01). CONCLUSION Salidroside can improve the abnormality of blood gas index, hypoxia symptoms and acid-base balance disorder, dysregulation of inflammatory factors caused by hypoxia in rats, and improve lung tissue injury and oxidative stress injury, which has a protective effect on lung tissue injury of rats exposed rapidly to the high-altitude plateau, and the effect is better than Rhodiola rosea capsule on the whole.
Collapse
Affiliation(s)
- Zihan Wang
- 1. College of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730000, China
- 2. Department of Pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Qianwen Guo
- 1. College of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730000, China
- 2. Department of Pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Jianghong Ma
- 1. College of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730000, China
- 2. Department of Pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Junfei Cheng
- 2. Department of Pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Anpeng Zhao
- 2. Department of Pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Wenbin Li
- 1. College of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730000, China
- 2. Department of Pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| | - Rong Wang
- 1. College of Pharmacy, Gansu University of Chinese Medicine, Lanzhou 730000, China
- 2. Department of Pharmacy, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Key Laboratory of the Plateau Medicine, Lanzhou 730050, China
| |
Collapse
|
9
|
Liu J, Xin Z, Huang Y, Yu J. Climate suitability assessment on the Qinghai-Tibet Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 816:151653. [PMID: 34793809 DOI: 10.1016/j.scitotenv.2021.151653] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/26/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
Climate is an important factor that affects livability, but the climate comfort model used for low altitudes is not applicable to high altitudes, and further study on climate suitability in high-altitude areas is needed. In response to the absence of high-altitude characteristics in the current climate comfort assessment methods, this study adds oxygen content and solar radiation as plateau characteristic indicators. We use the consulting graded method (CGM), least squares method (LSM) and questionnaire survey method (QSM) to obtain comprehensive weights for oxygen content, solar radiation and comfort index to build the Climate Suitability Index of Plateau (CSIP) and assess climate suitability on the Qinghai-Tibet Plateau. The CSIP decreases obviously as elevation increases from southeast to northwest on the Qinghai-Tibet Plateau, which means that the climate becomes increasingly unsuitable from southeast to northwest. The Qinghai-Tibet Plateau is divided into four regions-"very unsuitable" (83.8 × 104 km2, 32.4%), "unsuitable" (81.5 × 104 km2, 31.6%), "suitable" (67.9 × 104 km2, 26.3%), and "very suitable" (24.9 × 104 km2, 9.6%)-by the natural break method according to the CSIP. According to the different degrees of response of population density to CSIP, we plot the climate suitability line of the Qinghai-Tibet Plateau to provide basic theoretical support for regional planning in the Qinghai-Tibet region. The CSIP developed in this study provides a new climate suitability assessment method for high-altitude regions and a method for planning human activities on the Qinghai-Tibet Plateau from a climate-focused perspective.
Collapse
Affiliation(s)
- Jinhao Liu
- College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Zhongbao Xin
- College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.
| | - Yanzhang Huang
- College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Jia Yu
- College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| |
Collapse
|
10
|
Santos-Martínez LE, Gómez-Tejada RA, Murillo-Jauregui CX, Hoyos-Paladines RA, Poyares-Jardim CV, Orozco-Levi M. [Chronic exposure to altitude. Clinical characteristics and diagnosis]. ARCHIVOS DE CARDIOLOGIA DE MEXICO 2021; 91:500-507. [PMID: 33765369 PMCID: PMC8641469 DOI: 10.24875/acm.20000447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
La exposición crónica a la altitud se ha asociado a hipoxia hipobárica en quienes la experimentan. Dos entidades se han asociado a la hipoxia hipobárica: la hipertensión pulmonar de la alta altitud y el mal de montaña crónico. Se describen sus características fisiológicas y de la circulación pulmonar, así como su perfil clínico y el diagnóstico.
Collapse
Affiliation(s)
- Luis E Santos-Martínez
- Departamento de Hipertensión Pulmonar y Corazón Derecho, Unidad Médica de Alta Especialidad Hospital de Cardiología, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México.,Departamento de Cuidados Intensivos Posquirúrgicos Cardiovasculares, Secretaría de Salubridad y Asistencia, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México.,Departamento de Circulación Pulmonar, Asociación Latinoamericana del Tórax, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ricardo A Gómez-Tejada
- Departamento de Circulación Pulmonar, Asociación Latinoamericana del Tórax, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.,División de Neumología, Hospital de Clínicas José de San Martín, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Carla X Murillo-Jauregui
- Departamento de Circulación Pulmonar, Asociación Latinoamericana del Tórax, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.,Unidad de Fisiología y Fisiopatología Respiratoria, Instituto Boliviano de Biología de Altura, La Paz, Bolivia
| | - Rodrigo A Hoyos-Paladines
- Departamento de Circulación Pulmonar, Asociación Latinoamericana del Tórax, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.,Clínica de Hipertensión Pulmonar, Hospital Carlos Andrade Marín, Instituto Ecuatoriano de Seguridad Social, Quito, Ecuador
| | - Carlos V Poyares-Jardim
- Departamento de Circulación Pulmonar, Asociación Latinoamericana del Tórax, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.,Divisao de Pneumologia, Instituto do Coracao, InCor/HCFMUSP (Hospital das Clinicas da Universidade de Sao Paulo), Sao Paulo, Brasil
| | - Mauricio Orozco-Levi
- Departamento de Circulación Pulmonar, Asociación Latinoamericana del Tórax, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.,Servicio de Neumología, Hospital Internacional de Colombia, Fundación Cardiovascular de Colombia, Floridablanca, Colombia
| |
Collapse
|
11
|
Xu LB, Xiong J, Zhang YH, Dai Y, Ren XP, Ren YJ, Han D, Wei SH, Qi M. miR‑205‑3p promotes lung cancer progression by targeting APBB2. Mol Med Rep 2021; 24:588. [PMID: 34165160 PMCID: PMC8222966 DOI: 10.3892/mmr.2021.12227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 03/29/2021] [Indexed: 12/29/2022] Open
Abstract
Non-small cell lung cancer (NSCLC), a leading cause of cancer-associated mortality, has resulted in low survival rates and a high mortality worldwide. Accumulating evidence has suggested that microRNAs (miRs) play critical roles in the regulation of cancer progression and the present study aimed to explore the underlying mechanism of miR-205 in NSCLC. Reverse transcription-quantitative PCR was performed, which determined that miR-205 expression was upregulated in NSCLC, and the present study detected the upregulation of miR-205-3p in a number of NSCLC cell lines and NSCLC tissues. In addition, the mediation of amyloid β precursor protein-binding family B member 2 (APBB2) by miR-205-3p was demonstrated. Moreover, miR-205-3p was predicted to directly target the 3′untranslated region of APBB2, which was confirmed using a dual-luciferase reporter assay. It was found that lentivirus mediated-APBB2 knockdown could promote cellular viability and suppress apoptosis in NSCLC cells, as determined via MTT, TUNEL and flow cytometry assays. Thus, the current findings highlighted the potential promotive impact of miR-205-3p on NSCLC processes and may provide theoretical evidence for miR-205-3p as a potential clinical gene therapy target.
Collapse
Affiliation(s)
- Ling-Bin Xu
- Department of Pulmonary and Critical Care Medicine No. 2, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - Jie Xiong
- Department of Pulmonary and Critical Care Medicine No. 2, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - Ya-Hui Zhang
- Department of Orthopaedics, Xi'an Daxing Hospital, Xi'an, Shaanxi 710016, P.R. China
| | - Yun Dai
- Department of Thoracic Surgery, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - Xiao-Ping Ren
- Department of Pulmonary and Critical Care Medicine No. 2, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - Ya-Juan Ren
- Department of Pulmonary and Critical Care Medicine No. 2, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - Dong Han
- Department of Pulmonary and Critical Care Medicine No. 2, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - Sheng-Hong Wei
- Department of Pulmonary and Critical Care Medicine No. 2, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - Min Qi
- Imaging Center, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| |
Collapse
|
12
|
Schüttler D, Weckbach LT, Hamm W, Maier F, Kassem S, Schier J, Lackermair K, Brunner S. Effect of acute altitude exposure on ventilatory thresholds in recreational athletes. Respir Physiol Neurobiol 2021; 293:103723. [PMID: 34171484 DOI: 10.1016/j.resp.2021.103723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 06/01/2021] [Accepted: 06/18/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE High altitude (HA) training is frequently used in endurance sports and recreational athletes increasingly participate in cross mountain competitions. At high altitude aerobic physiology changes profoundly. Ventilatory thresholds (VTs) are measures for endurance performance but the impact of exposure to acute altitude (AA) on VTs in recreational athletes has been insufficiently explored to date and most studies investigated effects under normobaric hypoxia. METHODS In this cross-sectional study we investigated the effects of AA exposure at 2650 m/715 mbar on anerobic threshold (VT1) and respiratory compensation point (VT2) in a graded cycling test in 14 recreational athletes (4 female, 10 male) compared to baseline levels (521 m, 949 mbar). RESULTS At VT1, a decline in power output (PO) from median 115.5 W to 105.0 W (median -12.3 %, p = 0.032; Wilcoxon test) during exposure to HA was observed. VO2/body weight and VO2/heart rate decreased markedly (- 9.5 %, p = 0.016; -10.5 %, p = 0.012). At VT2 we found a significant decline of PO from 184.5-170.5 W (-13.1 %, p = 0.0014), of VO2/body weight and of VO2/heart rate (-10.1 %, p = 0.0015; -8.7 %, p = 0.002) compared to baseline values. Absolute VO2 decreased (-9.5 %, p = 0.0014 and -10.1 %, p = 0.0002) while minute ventilation and heart rates remained unchanged at both thresholds. CONCLUSION Our data allows a quantification of performance loss at HA in recreational athletes and demonstrates that VT-guided training intensities and workloads need to be adapted for training at HA.
Collapse
Affiliation(s)
- Dominik Schüttler
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany; Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Ludwig T Weckbach
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany; Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Munich, Germany; Institute of Cardiovascular Physiology and Pathophysiology, Biomedical Center, LMU Munich, Planegg-Martinsried, Germany
| | - Wolfgang Hamm
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Florian Maier
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Sari Kassem
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Johannes Schier
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany
| | - Korbinian Lackermair
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany
| | - Stefan Brunner
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Campus Grosshadern and Innenstadt, Ludwig-Maximilians University Munich (LMU), Munich, Germany.
| |
Collapse
|
13
|
Liu C, Chen X, Guo G, Xu X, Li X, Wei Q, Shen Y, Li H, Hao J, Tian YP, He K. Effects of Intermittent Normoxia on Chronic Hypoxic Pulmonary Hypertension and Right Ventricular Hypertrophy in Rats. High Alt Med Biol 2021; 22:184-192. [PMID: 33989063 DOI: 10.1089/ham.2020.0110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Liu, Chunlei, Xu Chen, Ge Guo, Xiang Xu, Xin Li, Qingxia Wei, Yanying Shen, Hanlu Li, Jianxiu Hao, Ya Ping Tian, and Kunlun He. Effects of intermittent normoxia on chronic hypoxic pulmonary hypertension and right ventricular hypertrophy in rats. High Alt Med Biol. 22: 184-192, 2021. Background: Individuals with chronically low arterial oxygen tension owing to high altitude develop elevated rates of pulmonary hypertension (PH) and right ventricular (RV) hypertrophy. However, the effects of the frequency and duration of normoxic exposure on PH and RV hypertrophy have not been adequately assessed; thus, we aimed to analyze the same. Materials and Methods: PH and RV hypertrophy were induced in 60 rats using a hypobaric chamber. Of these 60 rats, every 10 were exposed to normoxic conditions for 30 minutes once (1T/D), three times (3T/D), or five times daily (5T/D), or for one 150-minute recovery daily (1LT/D). Furthermore, 10 rats were housed in a normoxic environment, and another 10 were subjected to continuous hypoxia. After 4 weeks, hemodynamic measurements were recorded, and the hearts were harvested for pathomorphological observations. Results: Average pulmonary arterial pressures (PAP) of control rats and those exposed to hypobaric hypoxia were 14.1 and 32.3 mmHg, respectively. After 30 minutes of exposure to normoxia 3T/D, 5T/D, or 1LT/D, PAP values were reduced to 27.1, 27.9, or 26.8 mmHg, respectively. Four weeks of hypoxic exposure elevated the RV/heart weight (HW) ratios, while exposure to normoxia 3T/D, 5T/D, and 1LT/D significantly reduced RV/HW. In addition, exposure to normoxia 3T/D, 5T/D, 1LT/D reduced the percentage wall thickness of the pulmonary artery as well as the hypertrophy indices of atrial natriuretic peptide, brain natriuretic peptide, and myosin heavy chain 7 (MYH-7). Conclusions: Thirty-minute exposure to normoxic conditions of 3T/D, 5T/D, or 1LT/D effectively ameliorates PH and RV thickening.
Collapse
Affiliation(s)
- Chunlei Liu
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China.,Beijing Key Laboratory of Chronic Heart Failure Precision Medicine, Chinese PLA General Hospital, Beijing, China
| | - Xu Chen
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China
| | - Ge Guo
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China
| | - Xiang Xu
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China
| | - Xin Li
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China.,Beijing Key Laboratory of Chronic Heart Failure Precision Medicine, Chinese PLA General Hospital, Beijing, China
| | - Qingxia Wei
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China
| | - Yanying Shen
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China
| | - Hanlu Li
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China
| | - Jianxiu Hao
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China
| | - Ya Ping Tian
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China.,Beijing Key Laboratory of Chronic Heart Failure Precision Medicine, Chinese PLA General Hospital, Beijing, China
| | - Kunlun He
- Transformation Medicine Centre, Chinese PLA General Hospital, Beijing, China.,Beijing Key Laboratory of Chronic Heart Failure Precision Medicine, Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
14
|
Abstract
PURPOSE OF REVIEW Pulmonary hypertension is a deadly disease, the causes of which vary between geographical regions. Eighty four percentage of the world's population lives in majority countries (also called low-income and middle-income countries), yet data on pulmonary hypertension in these settings are proportionally scarce. This article provides a review of pulmonary hypertension in majority countries, focusing in detail on the most common causes in these regions, and highlights contextual challenges faced. RECENT FINDINGS Epidemiological data confirms a complex and overlapping array of causes, with pulmonary hypertension because of conditions such as rheumatic heart disease, HIV, schistosomiasis, chronic lung disease and sickle cell disease. Delayed pulmonary hypertension diagnosis remains a concern and is ascribed to a lack of resources and lack of pulmonary hypertension awareness by health professionals. Pulmonary hypertension diagnosis is frequently considered once signs of right heart failure emerge, while echocardiography and right heart catheterization are unavailable in many settings. Accurate data on the prevalence of pulmonary hypertension in many of these regions are needed and could be achieved by establishing and frequent review of national databases where the incident and prevalent pulmonary hypertension cases are captured. SUMMARY There is urgent need for pulmonary hypertension advocacy among clinicians in the primary, secondary and tertiary healthcare sectors of majority countries, and validated noninvasive diagnostic algorithms are needed. Increased awareness and early diagnosis are likely to improve outcomes of pulmonary hypertension patients in these regions, and potentially stimulate locally relevant research.
Collapse
|
15
|
Gorelova A, Berman M, Al Ghouleh I. Endothelial-to-Mesenchymal Transition in Pulmonary Arterial Hypertension. Antioxid Redox Signal 2021; 34:891-914. [PMID: 32746619 PMCID: PMC8035923 DOI: 10.1089/ars.2020.8169] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 07/23/2020] [Indexed: 12/14/2022]
Abstract
Endothelial-to-mesenchymal transition (EndMT) is a process that encompasses extensive transcriptional reprogramming of activated endothelial cells leading to a shift toward mesenchymal cellular phenotypes and functional responses. Initially observed in the context of embryonic development, in the last few decades EndMT is increasingly recognized as a process that contributes to a variety of pathologies in the adult organism. Within the settings of cardiovascular biology, EndMT plays a role in various diseases, including atherosclerosis, heart valvular disease, cardiac fibrosis, and myocardial infarction. EndMT is also being progressively implicated in development and progression of pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH). This review covers the current knowledge about EndMT in PH and PAH, and provides comprehensive overview of seminal discoveries. Topics covered include evidence linking EndMT to factors associated with PAH development, including hypoxia responses, inflammation, dysregulation of bone-morphogenetic protein receptor 2 (BMPR2), and redox signaling. This review amalgamates these discoveries into potential insights for the identification of underlying mechanisms driving EndMT in PH and PAH, and discusses future directions for EndMT-based therapeutic strategies in disease management.
Collapse
Affiliation(s)
- Anastasia Gorelova
- Heart, Lung and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Mariah Berman
- Heart, Lung and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Imad Al Ghouleh
- Heart, Lung and Blood Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
16
|
Assessing Suitability of Human Settlements in High-Altitude Area Using a Comprehensive Index Method: A Case Study of Tibet, China. SUSTAINABILITY 2021. [DOI: 10.3390/su13031485] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
With the steady advancement of the United Nations Sustainable Development Goals (SDGs), how to build a sustainable environment for human settlements has become a hot topic of research for scholars from various countries. Rational space utilization and resource allocation are the keys to enhancing human well-being and achieving sustainable human settlements. A comprehensive human settlement environment evaluation system, which includes 14 indicators from the natural environment, infrastructure, and public services, was established in this study. The results showed that the habitat suitability area only accounted for 1.61% (2.05% after removing the nature reserve) and all centered on cities and radiated to the surrounding areas. A belt-like suitability distribution pattern of “Yi Jiang Liang He” (i.e., Brahmaputra, Lhasa, and Nianchu Rivers) is formed, and a point-like suitability distribution pattern of the Chamdo Karub District, Nagqu Seni District, and Ngari Shiquanhe Town are formed. The results of the driving factor analysis indicate that the level of public health development in infrastructure and various indicators in public services are the main factors influencing human settlement. There is not much difference in the natural environment in the populated regions, so the suitability of the natural environment is not a significant driving factor. In addition, the reliability of the assessment results was verified by a questionnaire survey of residents in the three regions, and the subjective satisfaction of the residents agreed with the ranking results of the objective evaluation. The evaluation results of this study provide theoretical and directional guidance for the improvement of human settlements on the Qinghai–Tibet Plateau. It will be a useful tool for evaluating human settlements in the region and has a reference significance for the formulation of macro-policy in high-altitude regions.
Collapse
|
17
|
Ewalts M, Dawkins T, Boulet LM, Thijssen D, Stembridge M. The influence of increased venous return on right ventricular dyssynchrony during acute and sustained hypoxaemia. Exp Physiol 2020; 106:925-937. [PMID: 33369788 DOI: 10.1113/ep088657] [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] [Received: 03/31/2020] [Accepted: 12/19/2020] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Right ventricular dyssynchrony is a marker of function that is elevated in healthy individuals exposed to acute hypoxia, but does it remain elevated during sustained exposure to high altitude hypoxia, and can it be normalised by augmenting venous return? What is the main finding and its importance? For the first time it is demonstrated that (i) increasing venous return in acute hypoxia restores the synchrony of right ventricular contraction and (ii) dyssynchrony is evident after acclimatisation to high altitude, and remains sensitive to changes in venous return. Therefore, the interpretation of right ventricular dyssynchrony requires consideration the prevailing haemodynamic state. ABSTRACT Regional heterogeneity in timing of right ventricular (RV) contraction (RV dyssynchrony; RVD) occurs when pulmonary artery systolic pressure (PASP) is increased during acute hypoxia. Interestingly, RVD is not observed during exercise, a stimulus that increases both PASP and venous return. Therefore, we hypothesised that RVD in healthy humans is sensitive to changes in venous return, and examined whether (i) increasing venous return in acute hypoxia lowers RVD and (ii) if RVD is further exaggerated in sustained hypoxia, given increased PASP is accompanied by decreased ventricular filling at high altitude. RVD, PASP and right ventricular end-diastolic area (RVEDA) were assessed using transthoracic two-dimensional and speckle-tracking echocardiography during acute normobaric hypoxia ( F i O 2 = 0.12) and sustained exposure (5-10 days) to hypobaric hypoxia (3800 m). Venous return was augmented with lower body positive pressure at sea level (LBPP; +10 mmHg) and saline infusion at high altitude. PASP was increased in acute hypoxia (20 ± 6 vs. 28 ± 7, P < 0.001) concomitant to an increase in RVD (18 ± 7 vs. 38 ± 10, P < 0.001); however, the addition of LBPP during hypoxia decreased RVD (38 ± 0 vs. 26 ± 10, P < 0.001). Sustained hypoxia increased PASP (20 ± 4 vs. 26 ± 5, P = 0.008) and decreased RVEDA (24 ± 4 vs. 21 ± 2, P = 0.042), with RVD augmented (14 ± 5 vs. 31 ± 12, P = 0.001). Saline infusion increased RVEDA (21 ± 2 vs. 23 ± 3, P = 0.008) and reduced RVD (31 ± 12 vs. 20 ± 9, P = 0.001). In summary, an increase in PASP secondary to acute and sustained exposure to hypoxia augments RVD, which can be at least partly reduced via increased venous return.
Collapse
Affiliation(s)
- Michiel Ewalts
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK.,Department of Physiology, Radboudumc, Nijmegen, The Netherlands
| | - Tony Dawkins
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Lindsey M Boulet
- Centre for Heart Lung and Vascular Health, University of British Columbia, Kelowna, British Columbia, Canada
| | - Dick Thijssen
- Department of Physiology, Radboudumc, Nijmegen, The Netherlands
| | - Mike Stembridge
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| |
Collapse
|
18
|
Niu M, Singh S, Mi M, Bian P, Deji Z, Mima D, Li X. Safety and Efficacy of Therapeutic Erythrocytapheresis Treatment in Chronic Mountain Sickness Patients in Shigatse, Tibet, China. Med Sci Monit 2020; 26:e927853. [PMID: 33353927 PMCID: PMC7768795 DOI: 10.12659/msm.927853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background Therapeutic erythrocytapheresis (TEA) is a medical technology that separates erythrocytes from whole blood and has been used in various hematological conditions. However, reports on the use of TEA to treat chronic mountain sickness (CMS) are lacking. The aim of the present study was to evaluate the efficacy, safety, and use of TEA in treatment of CMS. Material/Methods A total of 32 patients living in the Shigatse area of Tibet (altitude 4000 m) who had CMS were treated with TEA. Clinical data, CMS score, Borg dyspnea score, 6-min walking test score, and NYHA classification values were collected prior to and after TEA therapy. Results TEA treatment significantly increased SpO2 (93.8±2.6 vs. 80.5±5.8%, P<0.001) and decreased red blood cell (5.77±0.70 vs. 7.48±0.67×1012/L, P<0.001), hematocrit (53.8±5.6 vs. 69.2±4.8%, P<0.001) and hemoglobin (178±16 vs. 236±14 g/L, P<0.001). Significantly lower systolic and diastolic blood pressure were also noted (P<0.001). Echocardiography showed higher left ventricle diameter (4.6±0.4 vs. 4.4±0.5 cm, P<0.01). TEA markedly decreased CMS scores (0.45±0.85 vs. 7.58±2.31, P<0.001), Borg dyspnea scale scores (0.48±0.73 vs. 0.88±0.81, P<0.001), and NYHA classification scores (P<0.05). Additionally, there was marked improvement in the 6-min walking test scores (578.5±83.1 vs. 550.4±79.0 m, P<0.001). The procedure was well tolerated, with no complications. Conclusions Our novel approach of treating CMS patients with TEA safely and effectively reduced erythrocytosis, which remains a fundamental challenge in CMS patients.
Collapse
Affiliation(s)
- Mingyuan Niu
- Department of Cardiology, Shigatse People's Hospital, Shigatse, Tibet, China (mainland)
| | - Shekhar Singh
- Department of Cardiology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China (mainland)
| | - Ma Mi
- Department of Cardiology, Shigatse People's Hospital, Shigatse, Tibet, China (mainland)
| | - Pian Bian
- Department of Cardiology, Shigatse People's Hospital, Shigatse, Tibet, China (mainland)
| | - Zhuoga Deji
- Department of Cardiology, Shigatse People's Hospital, Shigatse, Tibet, China (mainland)
| | - Duoji Mima
- Department of Cardiology, Shigatse People's Hospital, Shigatse, Tibet, China (mainland)
| | - Xiankai Li
- Department of Cardiology, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China (mainland)
| |
Collapse
|
19
|
Lyu Q, Bai Y, Cheng J, Liu H, Li S, Yang J, Wang Z, Ma Y, Jiang M, Dong D, Yan Y, Shi Q, Ren X, Ma J. Intermittent short-duration reoxygenation protects against simulated high altitude-induced pulmonary hypertension in rats. FASEB J 2020; 35:e21212. [PMID: 33230951 DOI: 10.1096/fj.202000533rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 11/04/2020] [Accepted: 11/09/2020] [Indexed: 12/17/2022]
Abstract
High-altitude pulmonary hypertension (HAPH) is a severe and progressive disease caused by chronic hypoxia and subsequent pulmonary vascular remodeling. No cure is currently available owing to an incomplete understanding about vascular remodeling. It is believed that hypoxia-induced diseases can be prevented by treating hypoxia. Thus, this study aimed to determine whether daily short-duration reoxygenation at sea level attenuates pulmonary hypertension under high-altitude hypoxia. To this end, a simulated 5000-m hypoxia rat model and hypoxic cultured human pulmonary artery smooth muscle cells were used to evaluate the effect of short-duration reoxygenation. Results show that intermittent, not continuous, short-duration reoxygenation effectively attenuates hypoxia-induced pulmonary hypertension. The mechanisms underlining the protective effects involved that intermittent, short-duration reoxygenation prevented functional and structural remodeling of pulmonary arteries and proliferation, migration, and phenotypic conversion of pulmonary artery smooth muscle cells under hypoxia. The specific genes or potential molecular pathways responsible for mediating the protective effects were also characterised by RNA sequencing. Further, the frequency and the total time of intermittent reoxygenation affected its preventive effect of HAPH, which was likely attributable to augmented oxidative stress. Hence, daily intermittent, not continuous, short-duration reoxygenation partially prevented pulmonary hypertension induced by 5000-m hypoxia in rats. This study is novel in revealing a new potential method in preventing HAPH. It gives insights into the selection and optimisation of oxygen supply schemes in high-altitude areas.
Collapse
Affiliation(s)
- Qiang Lyu
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Yungang Bai
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Jiuhua Cheng
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Huan Liu
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Shaohua Li
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Jing Yang
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Zhongchao Wang
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Yan Ma
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Min Jiang
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Dong Dong
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Yiquan Yan
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Qixin Shi
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Xinling Ren
- Department of Respiratory Diseases, Xi'an, China
| | - Jin Ma
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| |
Collapse
|
20
|
Zhuan B, Wang X, Wang MD, Li ZC, Yuan Q, Xie J, Yang Z. Hypoxia induces pulmonary artery smooth muscle dysfunction through mitochondrial fragmentation-mediated endoplasmic reticulum stress. Aging (Albany NY) 2020; 12:23684-23697. [PMID: 33221740 PMCID: PMC7762493 DOI: 10.18632/aging.103892] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 07/23/2020] [Indexed: 12/16/2022]
Abstract
Pulmonary arterial hypertension (PAH) is characterized by pulmonary artery smooth muscle cell (PASMC) dysfunction. However, the underlying mechanisms of PASMC dysfunction remain largely unknown. Here, we show that mitochondrial fragmentation contributes to PASMC dysfunction through enhancement of endoplasmic reticulum (ER) stress. PASMC dysfunction accompanied by mitochondrial fragmentation and ER stress was observed in the pulmonary arteries of hypoxia-induced rats with PAH, as well as isolated PASMCs under hypoxia. Treatment with Mdivi-1 inhibited mitochondrial fragmentation and ER stress and improved PASMC function in isolated PASMCs under hypoxia, while Drp1 overexpression increased mitochondrial fragmentation and ER stress, impairing PASMC function in isolated PASMCs under normoxia. However, inhibition of ER stress using ER stress inhibitors showed a negligible effect on mitochondrial morphology but improved PASMC function during hypoxia. Additionally, we found that mitochondrial fragmentation-promoted ER stress was dependent on mitochondrial reactive oxygen species. Furthermore, inhibition of mitochondrial fragmentation using Mdivi-1 attenuated mitochondrial fragmentation and ER stress in hypoxic PASMCs and improved the pulmonary artery smooth muscle function in hypoxic rats. These results suggest that hypoxia induces pulmonary artery smooth muscle dysfunction through mitochondrial fragmentation-mediated ER stress and that mitochondrial morphology is a potential target for treatment of hypoxia-induced pulmonary artery smooth muscle dysfunction.
Collapse
Affiliation(s)
- Bing Zhuan
- Department of Respiratory Medicine, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan 750000, China
| | - Xi Wang
- Department of Respiratory Medicine, The Affiliated Suzhou Science and Technology Town Hospital of Nanjing Medical University, Suzhou 215153, China
| | - Ming-Deng Wang
- Department of Intensive Care Unit, The Affiliated Suzhou Science and Technology Town Hospital of Nanjing Medical University, Suzhou 215153, China
| | - Zhi-Cai Li
- Department of Respiratory Medicine, The Affiliated Suzhou Science and Technology Town Hospital of Nanjing Medical University, Suzhou 215153, China
| | - Qun Yuan
- Department of Respiratory Medicine, The Affiliated Suzhou Science and Technology Town Hospital of Nanjing Medical University, Suzhou 215153, China
| | - Jun Xie
- Department of Thoracic Surgery, The Affiliated Suzhou Science and Technology Town Hospital of Nanjing Medical University, Suzhou 215153, China
| | - Zhao Yang
- Department of Respiratory Medicine, The Affiliated Suzhou Science and Technology Town Hospital of Nanjing Medical University, Suzhou 215153, China
| |
Collapse
|
21
|
Hannemann J, Glatzel A, Hillig J, Zummack J, Schumacher U, Lüneburg N, Harbaum L, Böger R. Upregulation of DDAH2 Limits Pulmonary Hypertension and Right Ventricular Hypertrophy During Chronic Hypoxia in Ddah1 Knockout Mice. Front Physiol 2020; 11:597559. [PMID: 33281630 PMCID: PMC7689360 DOI: 10.3389/fphys.2020.597559] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/30/2020] [Indexed: 12/13/2022] Open
Abstract
Objective: Chronic hypoxia causes pulmonary vasoconstriction leading to pulmonary hypertension and right ventricular hypertrophy. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthesis; its level increases in hypoxia (HX) concomitantly with reduced activity of dimethylarginine dimethylaminohydrolases (DDAH-1 and DDAH-2), enzymes metabolizing ADMA. Ddah1 knockout (KO) mice may therefore help to understand the pathophysiological roles of this enzyme and its substrate, ADMA, in the development of hypoxia-associated pulmonary hypertension. Methods: Ddah1 KO mice and their wild-type (WT) littermates were subjected to normoxia (NX) or for 21 days. We measured ADMA concentration in plasma and lungs, DDAH1 and DDAH2 mRNA and protein expression in the lungs, right ventricular systolic pressure (RVSP), right ventricular hypertrophy by the Fulton index, and cardiomyocyte hypertrophy by dystrophin staining of the heart. Results: Ddah1 KO mice had higher ADMA concentrations in plasma and in lung tissue than WT in NX (p < 0.05). ADMA significantly increased in WT-HX in plasma and lungs, while there were no significant differences in WT-HX vs. KO-HX. This finding was paralleled by a 38 ± 13% reduction in Ddah1 but not Ddah2 mRNA expression, and reduced DDAH1 protein expression but stable DDAH2 protein levels in WT mice. Ddah1 KO mice showed significant elevation of DDAH2 protein but not mRNA levels, which further increased in HX. HX led to increased RVSP and right ventricular hypertrophy in both, WT and KO mice, with no significant differences between both genotypes. Conclusions: Chronic hypoxia causes an elevation of ADMA, which may impair NO production and lead to endothelial dysfunction and vasoconstriction. Downregulation of DDAH1 expression and activity may be involved in this; however, knockout of the Ddah1 gene does not modify the hypoxia-induced pathophysiological changes of pulmonary blood pressure and right ventricular hypertrophy, possibly due to compensatory upregulation of DDAH2 protein.
Collapse
Affiliation(s)
- Juliane Hannemann
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute DECIPHER (German-Chilean Institute for Research on Pulmonary Hypoxia and Its Health Sequelae), Hamburg, Germany
| | - Antonia Glatzel
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jonas Hillig
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute DECIPHER (German-Chilean Institute for Research on Pulmonary Hypoxia and Its Health Sequelae), Hamburg, Germany
| | - Julia Zummack
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute DECIPHER (German-Chilean Institute for Research on Pulmonary Hypoxia and Its Health Sequelae), Hamburg, Germany
| | - Udo Schumacher
- Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicole Lüneburg
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lars Harbaum
- Department of Pulmonology, II. Medical Clinic and Policlinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Rainer Böger
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute DECIPHER (German-Chilean Institute for Research on Pulmonary Hypoxia and Its Health Sequelae), Hamburg, Germany
| |
Collapse
|
22
|
Yu J, Yu L, Li Y, Hu F. Iron deficiency is a possible risk factor causing right heart failure in Tibetan children living in high altitude area. Medicine (Baltimore) 2020; 99:e21133. [PMID: 32702866 PMCID: PMC7373578 DOI: 10.1097/md.0000000000021133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The aim of the study is to discuss the risk factor of right heart failure (RHF) especially the association of iron deficiency with RHF in Tibetan children who live in high altitude area. In this retrospective study, we collected the data of Tibetan children from January 2011 to December 2018 in our hospital. The patients included in the study had the following data: age, gender, ferritin, echocardiography, hemoglobin, C-reaction protein, and altitude of residence. According to whether RHF was diagnosed, the patients were divided into RHF group and non-RHF group. Totally 133 patients were included with 59 in RHF group and 74 in non-RHF group. In single factor analysis, age (P = .008), altitude of residence (P < .001), ferritin (P < .001), and pulmonary arterial systolic pressure (P < .001) showed significant difference between the 2 groups. Binary logistic regression was performed to further identify the association of the clinical factors with RHF. Higher pulmonary arterial systolic pressure (odds ratio: 29.303, 95% confidence interval: 5.249-163.589, P < .001) and lower ferritin level (odds ratio: 5.849, 95% confidence interval: 1.585-21.593, P = .008) were independent risk factors associated with RHF. In receiver-operating characteristic curve, the optimal cutoff value of ferritin level was 14.6 μg/L with the sensitivity of 81.4% and specificity of 89.2%. As continuous variable, the correlation between ferritin and RHF was not certain (P = .281). Due to the possibility that iron deficiency be a risk factor of RHF in Tibetan children, prevention and treatment of iron deficiency might be a potential way in reducing the incidence of RHF in this high altitude area.
Collapse
Affiliation(s)
- Jiayun Yu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital
| | - Li Yu
- Department of Pediatrics, West China Second University Hospital, Sichuan University
- Key Laboratory of Birth Defect and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, China
| | - Yifei Li
- Department of Pediatrics, West China Second University Hospital, Sichuan University
- Key Laboratory of Birth Defect and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, China
| | - Fan Hu
- Department of Pediatrics, West China Second University Hospital, Sichuan University
- Key Laboratory of Birth Defect and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, China
| |
Collapse
|
23
|
Sommer N, Alebrahimdehkordi N, Pak O, Knoepp F, Strielkov I, Scheibe S, Dufour E, Andjelković A, Sydykov A, Saraji A, Petrovic A, Quanz K, Hecker M, Kumar M, Wahl J, Kraut S, Seeger W, Schermuly RT, Ghofrani HA, Ramser K, Braun T, Jacobs HT, Weissmann N, Szibor M. Bypassing mitochondrial complex III using alternative oxidase inhibits acute pulmonary oxygen sensing. SCIENCE ADVANCES 2020; 6:eaba0694. [PMID: 32426457 PMCID: PMC7159913 DOI: 10.1126/sciadv.aba0694] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 01/22/2020] [Indexed: 05/02/2023]
Abstract
Mitochondria play an important role in sensing both acute and chronic hypoxia in the pulmonary vasculature, but their primary oxygen-sensing mechanism and contribution to stabilization of the hypoxia-inducible factor (HIF) remains elusive. Alteration of the mitochondrial electron flux and increased superoxide release from complex III has been proposed as an essential trigger for hypoxic pulmonary vasoconstriction (HPV). We used mice expressing a tunicate alternative oxidase, AOX, which maintains electron flux when respiratory complexes III and/or IV are inhibited. Respiratory restoration by AOX prevented acute HPV and hypoxic responses of pulmonary arterial smooth muscle cells (PASMC), acute hypoxia-induced redox changes of NADH and cytochrome c, and superoxide production. In contrast, AOX did not affect the development of chronic hypoxia-induced pulmonary hypertension and HIF-1α stabilization. These results indicate that distal inhibition of the mitochondrial electron transport chain in PASMC is an essential initial step for acute but not chronic oxygen sensing.
Collapse
Affiliation(s)
- Natascha Sommer
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Nasim Alebrahimdehkordi
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Oleg Pak
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Fenja Knoepp
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Ievgen Strielkov
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Susan Scheibe
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Eric Dufour
- Faculty of Medicine and Health Technology, Tampere University, FI-33014 Tampere, Finland
| | - Ana Andjelković
- Faculty of Medicine and Health Technology, Tampere University, FI-33014 Tampere, Finland
| | - Akylbek Sydykov
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Alireza Saraji
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Aleksandar Petrovic
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Karin Quanz
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Matthias Hecker
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Manish Kumar
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Joel Wahl
- Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Simone Kraut
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Werner Seeger
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Ralph T. Schermuly
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
| | - Hossein A. Ghofrani
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
- Department of Medicine, Imperial College London, Du Cane Road, Hammersmith Campus, London W12 0NN, UK
| | - Kerstin Ramser
- Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Thomas Braun
- Department I, Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, D-61231 Bad Nauheim, Germany
| | - Howard T. Jacobs
- Faculty of Medicine and Health Technology, Tampere University, FI-33014 Tampere, Finland
| | - Norbert Weissmann
- Excellence Cluster Cardio-Pulmonary Institute (CPI), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, D-35392 Giessen, Germany
- Corresponding author. (M.S.); (N.W.)
| | - Marten Szibor
- Faculty of Medicine and Health Technology, Tampere University, FI-33014 Tampere, Finland
- Corresponding author. (M.S.); (N.W.)
| |
Collapse
|
24
|
Siques P, Brito J, Schwedhelm E, Pena E, León-Velarde F, De La Cruz JJ, Böger RH, Hannemann J. Asymmetric Dimethylarginine at Sea Level Is a Predictive Marker of Hypoxic Pulmonary Arterial Hypertension at High Altitude. Front Physiol 2019; 10:651. [PMID: 31191349 PMCID: PMC6545974 DOI: 10.3389/fphys.2019.00651] [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: 02/01/2019] [Accepted: 05/08/2019] [Indexed: 12/18/2022] Open
Abstract
Background: Prolonged exposure to altitude-associated chronic hypoxia (CH) may cause high-altitude pulmonary hypertension (HAPH). Chronic intermittent hypobaric hypoxia (CIH) occurs in individuals who commute between sea level and high altitude. CIH is associated with repetitive acute hypoxic acclimatization and conveys the long-term risk of HAPH. As nitric oxide (NO) regulates pulmonary vascular tone and asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthesis, we investigated whether ADMA concentration at sea level predicts HAPH among Chilean frontiers personnel exposed to 6 months of CIH. Methods: In this prospective study, 123 healthy army draftees were subjected to CIH (5 days at 3,550 m, 2 days at sea level) for 6 months. In 100 study participants with complete data, ADMA, symmetric dimethylarginine (SDMA), L-arginine, arterial oxygen saturation (SaO2), systemic blood pressure, and hematocrit were assessed at months 0 (sea level), 1, 4, and 6. Acclimatization to altitude was determined using the Lake Louise Score (LLS) and the presence of acute mountain sickness (AMS). Echocardiography was performed after 6 months of CIH in 43 individuals with either good (n = 23) or poor (n = 20) acclimatization. Results: SaO2 acutely decreased at altitude and plateaued at 90% thereafter. ADMA increased and SDMA decreased during the study course. The incidence of AMS and the LLS was high after the first ascent (53 and 3.1 ± 2.4) and at 1 month of CIH (47 and 3.0 ± 2.6), but decreased to 20 and 1.4 ± 2.0 at month 6 (both p < 0.001). Eighteen participants (42%) showed a mean pulmonary arterial pressure (mPAP) >25 mm Hg, out of which 9 (21%) were classified as HAPH (mPAP ≥ 30 mm Hg). ADMA at sea level was significantly associated with mPAP at high altitude in month 6 (R = 0.413; p = 0.007). In ROC analysis, a cutoff for baseline ADMA of 0.665 μmol/L was determined to predict HAPH (mPAP > 30 mm Hg) with a sensitivity of 100% and a specificity of 63.6%. Conclusions: ADMA concentration increases during CIH. ADMA at sea level is an independent predictive biomarker of HAPH. SDMA concentration decreases during CIH and shows no association with HAPH. Our data support a role of impaired NO-mediated pulmonary vasodilation in the pathogenesis of HAPH.
Collapse
Affiliation(s)
- Patricia Siques
- Institute of Health Studies, Universidad Arturo Prat, Iquique, Chile.,Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany and Iquique, Chile
| | - Julio Brito
- Institute of Health Studies, Universidad Arturo Prat, Iquique, Chile.,Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany and Iquique, Chile
| | - Edzard Schwedhelm
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Eduardo Pena
- Institute of Health Studies, Universidad Arturo Prat, Iquique, Chile.,Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany and Iquique, Chile
| | - Fabiola León-Velarde
- Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany and Iquique, Chile.,Department of Biological and Physiological Sciences, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Juan José De La Cruz
- Department of Preventive Medicine and Public Health, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rainer H Böger
- Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany and Iquique, Chile.,Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Juliane Hannemann
- Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany and Iquique, Chile.,Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
25
|
Mazzuca E, Aliverti A, Miserocchi G. Understanding Vasomotion of Lung Microcirculation by In Vivo Imaging. J Imaging 2019; 5:jimaging5020022. [PMID: 34460470 PMCID: PMC8320900 DOI: 10.3390/jimaging5020022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 01/17/2019] [Accepted: 01/18/2019] [Indexed: 11/16/2022] Open
Abstract
The balance of lung extravascular water depends upon the control of blood flow in the alveolar distribution vessels that feed downstream two districts placed in parallel, the corner vessels and the alveolar septal network. The occurrence of an edemagenic condition appears critical as an increase in extravascular water endangers the thinness of the air-blood barrier, thus negatively affecting the diffusive capacity of the lung. We exposed anesthetized rabbits to an edemagenic factor (12% hypoxia) for 120 min and followed by in vivo imaging the micro-vascular morphology through a "pleural window" using a stereo microscope at a magnification of 15× (resolution of 7.2 μm). We measured the change in diameter of distribution vessels (50-200 μm) and corner vessels (<50 μm). On average, hypoxia caused a significant decrease in diameter of both smaller distribution vessels (about ~50%) and corner vessels (about ~25%) at 30 min. After 120 min, reperfusion occurred. Regional differences in perivascular interstitial volume were observed and could be correlated with differences in blood flow control. To understand such difference, we modelled imaged alveolar capillary units, obtained by Voronoi method, integrating microvascular pressure parameters with capillary filtration. Results of the analysis suggested that at 120 min, alveolar blood flow was diverted to the corner vessels in larger alveoli, which were found also to undergo a greater filtration indicating greater proneness to develop lung edema.
Collapse
Affiliation(s)
- Enrico Mazzuca
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, 20133 Milan, Italy
| | - Andrea Aliverti
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, 20133 Milan, Italy
| | - Giuseppe Miserocchi
- Department of Experimental Medicine, Università di Milano Bicocca, 20900 Milan, Italy
- Correspondence: ; Tel.: +39-335-248-452
| |
Collapse
|
26
|
Joyce K, Lucas S, Imray C, Balanos G, Wright AD. Advances in the available non-biological pharmacotherapy prevention and treatment of acute mountain sickness and high altitude cerebral and pulmonary oedema. Expert Opin Pharmacother 2018; 19:1891-1902. [DOI: 10.1080/14656566.2018.1528228] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- K.E. Joyce
- School of Sport, Exercise, & Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - S.J.E. Lucas
- School of Sport, Exercise, & Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - C.H.E. Imray
- Department of Vascular Surgery, University Hospitals of Coventry and Warwickshire; Warwick Medical School, Coventry, UK
| | - G.M Balanos
- School of Sport, Exercise, & Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - A. D. Wright
- Department of Medicine, University of Birmingham, Edgbaston, UK
| |
Collapse
|
27
|
Daily Chronic Intermittent Hypobaric Hypoxia Does Not Induce Chronic Increase in Pulmonary Arterial Pressure Assessed by Echocardiography. Can Respir J 2018; 2018:9649716. [PMID: 29808103 PMCID: PMC5902055 DOI: 10.1155/2018/9649716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/25/2018] [Indexed: 11/17/2022] Open
Abstract
Chronic hypoxia causes pulmonary vascular remodeling resulting in persistently increased pulmonary arterial pressures (PAP) even after return to normoxia. Recently, interest in chronic intermittent hypobaric hypoxia (CIHH) was raised because it occurs in subjects working at high altitude (HA) but living in lowland. However, effects of daily CIHH on PAP are unknown. In this pilot study, we included 8 healthy subjects working at (2650 m) each workday for 8-9 h while living and sleeping at LA and 8 matched control subjects living and working at LA. Cardiorespiratory measurements including echocardiography at rest and during exercise were performed at LA (Munich, 530 m) and HA (Zugspitze, 2650 m). Hemoglobin was higher in CIHH subjects. LA echocardiography showed normal right and left cardiac dimensions and function in all subjects. Systolic PAP (sPAP) and tricuspid annular plane systolic excursion (TAPSE) at rest were similar in both groups. Resting blood gas analysis (BGA) at HA revealed decreased pCO2 in CIHH compared to controls (HA: 28.4 versus 31.7 mmHg, p=0.01). During exercise, sPAP was lower in CIHH subjects compared to controls (LA: 28.7 versus 35.3 mmHg, p=0.02; HA: 26.3 versus 33.6 mmHg, p=0.04) and peripheral oxygen saturation (SpO2) was higher. In sum, subjects exposed to CIHH showed no signs of pulmonary vascular remodeling.
Collapse
|
28
|
Inhibition of mitochondrial fission prevents hypoxia-induced metabolic shift and cellular proliferation of pulmonary arterial smooth muscle cells. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2891-2903. [DOI: 10.1016/j.bbadis.2017.07.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 07/17/2017] [Accepted: 07/20/2017] [Indexed: 12/20/2022]
|