1
|
Murphey JT, Temple JL, Hostler D. Taste and Appetite at Altitude: A Comprehensive Review of Sensory and Hunger Modulation in High-Altitude Environments. High Alt Med Biol 2024. [PMID: 39122250 DOI: 10.1089/ham.2024.0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2024] Open
Abstract
Introduction: Individuals living or working at high altitudes typically experience altered taste perceptions and reduced appetite. These changes can lead to nutritional deficiencies, affecting the energy balance and body composition. Methods: We conducted a nonsystematic review of PubMed to explore these phenomena and expound on their findings to offer additional insights. Results: Changes in taste and perception are common and typically lead to loss of mass. There are limited practical solutions to mitigate these challenges. Discussion: Gradual acclimatization and tailored nutritional strategies are required to enhance health and performance in high-altitude environments. This review provides critical insights into the intersection of altitude, nutrition, and health.
Collapse
Affiliation(s)
- Joshua T Murphey
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York, USA
| | - Jennifer L Temple
- Nutrition and Health Research Laboratory, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York, USA
| | - David Hostler
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York, USA
| |
Collapse
|
2
|
Riha I, Salameh A, Hoschke A, Raffort C, Koedel J, Rassler B. Hypoxia-Induced Pulmonary Injury-Adrenergic Blockade Attenuates Nitrosative Stress, and Proinflammatory Cytokines but Not Pulmonary Edema. J Cardiovasc Dev Dis 2024; 11:195. [PMID: 39057617 PMCID: PMC11277000 DOI: 10.3390/jcdd11070195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 06/24/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024] Open
Abstract
Hypoxia can induce pulmonary edema (PE) and inflammation. Furthermore, hypoxia depresses left ventricular (LV) inotropy despite sympathetic activation. To study the role of hypoxic sympathetic activation, we investigated the effects of hypoxia with and without adrenergic blockade (AB) on cardiovascular dysfunction and lung injury, i.e., pulmonary edema, congestion, inflammation, and nitrosative stress. Eighty-six female rats were exposed for 72 h to normoxia or normobaric hypoxia and received infusions with NaCl, prazosin, propranolol, or prazosin-propranolol combination. We evaluated hemodynamic function and performed histological and immunohistochemical analyses of the lung. Hypoxia significantly depressed LV but not right ventricular (RV) inotropic and lusitropic functions. AB significantly decreased LV function in both normoxia and hypoxia. AB effects on RV were weaker. Hypoxic rats showed signs of moderate PE and inflammation. This was accompanied by elevated levels of tumor necrosis factor α (TNFα) and nitrotyrosine, a marker of nitrosative stress in the lungs. In hypoxia, all types of AB markedly reduced both TNFα and nitrotyrosine. However, AB did not attenuate PE. The results suggest that hypoxia-induced sympathetic activation contributes to inflammation and nitrosative stress in the lungs but not to PE. We suggest that AB in hypoxia aggravates hypoxia-induced inotropic LV dysfunction and backlog into the pulmonary circulation, thus promoting PE.
Collapse
Affiliation(s)
- Isabel Riha
- Carl-Ludwig-Institute of Physiology, University of Leipzig, 04103 Leipzig, Germany; (I.R.); (A.H.)
| | - Aida Salameh
- Department of Pediatric Cardiology, Heart Centre, University of Leipzig, 04289 Leipzig, Germany; (A.S.); (C.R.)
| | - Annekathrin Hoschke
- Carl-Ludwig-Institute of Physiology, University of Leipzig, 04103 Leipzig, Germany; (I.R.); (A.H.)
| | - Coralie Raffort
- Department of Pediatric Cardiology, Heart Centre, University of Leipzig, 04289 Leipzig, Germany; (A.S.); (C.R.)
| | - Julia Koedel
- Institute of Pathology, University of Leipzig, 04103 Leipzig, Germany;
| | - Beate Rassler
- Carl-Ludwig-Institute of Physiology, University of Leipzig, 04103 Leipzig, Germany; (I.R.); (A.H.)
| |
Collapse
|
3
|
Gatterer H, Villafuerte FC, Ulrich S, Bhandari SS, Keyes LE, Burtscher M. Altitude illnesses. Nat Rev Dis Primers 2024; 10:43. [PMID: 38902312 DOI: 10.1038/s41572-024-00526-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/02/2024] [Indexed: 06/22/2024]
Abstract
Millions of people visit high-altitude regions annually and more than 80 million live permanently above 2,500 m. Acute high-altitude exposure can trigger high-altitude illnesses (HAIs), including acute mountain sickness (AMS), high-altitude cerebral oedema (HACE) and high-altitude pulmonary oedema (HAPE). Chronic mountain sickness (CMS) can affect high-altitude resident populations worldwide. The prevalence of acute HAIs varies according to acclimatization status, rate of ascent and individual susceptibility. AMS, characterized by headache, nausea, dizziness and fatigue, is usually benign and self-limiting, and has been linked to hypoxia-induced cerebral blood volume increases, inflammation and related trigeminovascular system activation. Disruption of the blood-brain barrier leads to HACE, characterized by altered mental status and ataxia, and increased pulmonary capillary pressure, and related stress failure induces HAPE, characterized by dyspnoea, cough and exercise intolerance. Both conditions are progressive and life-threatening, requiring immediate medical intervention. Treatment includes supplemental oxygen and descent with appropriate pharmacological therapy. Preventive measures include slow ascent, pre-acclimatization and, in some instances, medications. CMS is characterized by excessive erythrocytosis and related clinical symptoms. In severe CMS, temporary or permanent relocation to low altitude is recommended. Future research should focus on more objective diagnostic tools to enable prompt treatment, improved identification of individual susceptibilities and effective acclimatization and prevention options.
Collapse
Affiliation(s)
- Hannes Gatterer
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy.
- Institute for Sports Medicine, Alpine Medicine and Health Tourism (ISAG), UMIT TIROL-Private University for Health Sciences and Health Technology, Hall in Tirol, Austria.
| | - Francisco C Villafuerte
- Laboratorio de Fisiología del Transporte de Oxígeno y Adaptación a la Altura - LID, Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias e Ingeniería, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Sanjeeb S Bhandari
- Mountain Medicine Society of Nepal, Kathmandu, Nepal
- Emergency Department, UPMC Western Maryland Health, Cumberland, MD, USA
| | - Linda E Keyes
- Department of Emergency Medicine, University of Colorado, Aurora, CO, USA
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
4
|
Ali M, Choudhary R, Singh K, Kumari S, Kumar R, Graham BB, Pasha MAQ, Rabyang S, Thinlas T, Mishra A. Hypobaric hypoxia modulated structural characteristics of circulating cell-free DNA in high-altitude pulmonary edema. Am J Physiol Lung Cell Mol Physiol 2024; 326:L496-L507. [PMID: 38349115 DOI: 10.1152/ajplung.00245.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 01/10/2024] [Accepted: 01/25/2024] [Indexed: 04/07/2024] Open
Abstract
The utility of cell-free (cf) DNA has extended as a surrogate or clinical biomarker for various diseases. However, a more profound and expanded understanding of the diverse cfDNA population and its correlation with physiological phenotypes and environmental factors is imperative for using its full potential. The high-altitude (HA; altitude > 2,500 m above sea level) environment characterized by hypobaric hypoxia offers an observational case-control design to study the differential cfDNA profile in patients with high-altitude pulmonary edema (HAPE) (number of subjects, n = 112) and healthy HA sojourners (n = 111). The present study investigated cfDNA characteristics such as concentration, fragment length size, degree of integrity, and subfractions reflecting mitochondrial-cfDNA copies in the two groups. The total cfDNA level was significantly higher in patients with HAPE, and the level increased with increasing HAPE severity (P = 0.0036). A lower degree of cfDNA integrity of 0.346 in patients with HAPE (P = 0.001) indicated the prevalence of shorter cfDNA fragments in circulation in patients compared with the healthy HA sojourners. A significant correlation of cfDNA characteristics with the peripheral oxygen saturation levels in the patient group demonstrated the translational relevance of cfDNA molecules. The correlation was further supported by multivariate logistic regression and receiver operating characteristic curve. To our knowledge, our study is the first to highlight the association of higher cfDNA concentration, a lower degree of cfDNA integrity, and increased mitochondrial-derived cfDNA population with HAPE disease severity. Further deep profiling of cfDNA fragments, which preserves cell-type specific genetic and epigenetic features, can provide dynamic physiological responses to hypoxia.NEW & NOTEWORTHY This study observed altered cell-free (cf) DNA fragment patterns in patients with high-altitude pulmonary edema and the significant correlation of these patterns with peripheral oxygen saturation levels. This suggests deep profiling of cfDNA fragments in the future may identify genetic and epigenetic mechanisms underlying physiological and pathophysiological responses to hypoxia.
Collapse
Affiliation(s)
- Manzoor Ali
- Cardio Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Raushni Choudhary
- Cardio Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Kanika Singh
- Cardio Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
| | - Swati Kumari
- Cardio Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Rahul Kumar
- Department of Medicine, University of California, San Francisco, California, United States
- Lung Biology Center, Zuckerberg San Francisco General Hospital, San Francisco, California, United States
| | - Brian B Graham
- Department of Medicine, University of California, San Francisco, California, United States
- Lung Biology Center, Zuckerberg San Francisco General Hospital, San Francisco, California, United States
| | | | - Stanzen Rabyang
- Department of Medicine, Sonam Norboo Memorial Hospital, Leh, India
| | - Tashi Thinlas
- Department of Medicine, Sonam Norboo Memorial Hospital, Leh, India
| | - Aastha Mishra
- Cardio Respiratory Disease Unit, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| |
Collapse
|
5
|
Luks AM, Beidleman BA, Freer L, Grissom CK, Keyes LE, McIntosh SE, Rodway GW, Schoene RB, Zafren K, Hackett PH. Wilderness Medical Society Clinical Practice Guidelines for the Prevention, Diagnosis, and Treatment of Acute Altitude Illness: 2024 Update. Wilderness Environ Med 2024; 35:2S-19S. [PMID: 37833187 DOI: 10.1016/j.wem.2023.05.013] [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: 12/27/2022] [Revised: 04/14/2023] [Accepted: 05/17/2023] [Indexed: 10/15/2023]
Abstract
To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for prevention, diagnosis, and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. Recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches for managing each form of acute altitude illness that incorporate these recommendations as well as recommendations on how to approach high altitude travel following COVID-19 infection. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in Wilderness & Environmental Medicine in 2010 and the subsequently updated WMS Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness published in 2014 and 2019.
Collapse
Affiliation(s)
- Andrew M Luks
- Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington, Seattle, WA
| | - Beth A Beidleman
- Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, MA
| | - Luanne Freer
- Everest ER, Himalayan Rescue Association, Kathmandu, Nepal
| | - Colin K Grissom
- Pulmonary and Critical Care Medicine, Intermountain Healthcare and the University of Utah, Salt Lake City, UT
| | - Linda E Keyes
- Department of Emergency Medicine, Section of Wilderness Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO
| | - Scott E McIntosh
- Department of Emergency Medicine, University of Utah Health, Salt Lake City, UT
| | - George W Rodway
- Department of Family Medicine-Sports Medicine, University of Nevada, Reno School of Medicine, Reno, NV
| | - Robert B Schoene
- Division of Pulmonary and Critical Care Medicine, Sound Physicians, St. Mary's Medical Center and Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco, CA
| | - Ken Zafren
- Department of Emergency Medicine, Stanford University School of Medicine, Stanford, CA
- Himalayan Rescue Association, Kathmandu, Nepal
| | - Peter H Hackett
- Altitude Research Center, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| |
Collapse
|
6
|
Shen TC, Lin MC, Lin CL, Lin WH, Chuang BK. Acute mountain sickness on Jade Mountain: Results from the real-world practice (2018-2019). J Formos Med Assoc 2024:S0929-6646(24)00083-4. [PMID: 38331638 DOI: 10.1016/j.jfma.2024.01.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/24/2023] [Accepted: 01/28/2024] [Indexed: 02/10/2024] Open
Abstract
Acute mountain sickness (AMS) is initiated in response to a hypoxic and hypobaric environment at a high altitude. The precise prevalence of AMS in Jade Mountain climbers remained largely unknown, particularly data obtained from real medical consultations. An overnight stay at the Pai-Yun Lodge (3402 m) is usually required before an ascent of the Jade Mountain. Since 2004, a Pai-Yun Clinic has been established in the Pai-Yun Lodge. The Pai-Yun Clinic provided regular and emergency medical service every weekend. We conducted a retrospective study by using medical records from the Pai-Yun Clinic between 2018 and 2019. A total of 1021 patients were enrolled, with 56.2 % males. Different age groups were 3.2 %, 54.5 %, 37.9 %, and 4.4 % in <20, 20-39, 40-59, and ≥60 years, respectively. There were 582 (57.0 %) patients diagnosed to have AMS (230 [39.5 %] were mild type and 352 [60.5 %] were severe type). The factors associated with AMS development included young age, absence of climbing history (>3000 m) within the last 3 months, first climbing (>3000 m) experience, taking preventive medication, low oxygen saturation, and a high Lake Louise AMS score (LLAMSS). The factors associated with AMS severity included absence of taking preventive medication, low oxygen saturation, and a high LLAMSS. Approximately 15 % of Jade Mountain climbers needed medical service, of which 60 % had AMS. 60 % of patients with AMS must require oxygen supply or medication prescription. Oxygen saturation measure and LLAMSS evaluation are reasonable tools to predict the occurrence and severity of AMS on Jade Mountain.
Collapse
Affiliation(s)
- Te-Chun Shen
- Division of Critical Care Medicine, Chu Shang Show Chwan Hospital, Nantou, Taiwan; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan; School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan
| | - Mei-Chen Lin
- Department of Nursing, Chu Shang Show Chwan Hospital, Nantou, Taiwan
| | - Cheng-Li Lin
- Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan
| | - Wen-Ho Lin
- Management Office, Jade Mountain National Park, Nantou, Taiwan
| | - Bi-Kun Chuang
- Department of Otorhinolaryngology, Chu Shang Show Chwan Hospital, Nantou, Taiwan.
| |
Collapse
|
7
|
Pichler Hefti J, Jean D, Rosier AJ, Derstine M, Hillebrandt D, Horakova L, Keyes LE, Mateikaitė-Pipirienė K, Paal P, Andjelkovic M, Beidlemann BA, Kriemler S. High-Altitude Pulmonary Edema in Women: A Scoping Review-UIAA Medical Commission Recommendations. High Alt Med Biol 2023; 24:268-273. [PMID: 37906126 DOI: 10.1089/ham.2023.0054] [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: 11/02/2023] Open
Abstract
Pichler Hefti, Jacqueline, Dominique Jean, Alison Rosier, Mia Derstine, David Hillebrandt, Lenka Horakova, Linda E. Keyes, Kastė Mateikaitė-Pipirienė, Peter Paal, Marija Andjelkovic, Beth Beidlemann, and Susi Kriemler. High-altitude pulmonary edema in women: a scoping review-UIAA Medical Commission Recommendations. High Alt Med Biol. 24:268-273, 2023. Background: High-altitude pulmonary edema (HAPE) can occur >2,500-3,000 m asl and is a life-threatening medical condition. This scoping review aims to summarize the current data on sex differences in HAPE. Methods: The International Climbing and Mountaineering Federation (UIAA) Medical Commission convened an international author team to review women's health issues at high altitude. Pertinent literature from PubMed and Cochrane was identified by keyword search combinations (including HAPE), with additional publications found by hand search. The primary search focus was for original articles that included minimum one woman and at least a rudimentary subgroup analysis. Results: The literature search yielded 7,165 articles, 416 of which were relevant for HAPE, and 7 of which were ultimately included here. Six were case series, consistently reporting a lower HAPE prevalence in women. The one retrospective case-control study reported male HAPE prevalence at 10/100,000 and female at 0.74/100,000. No studies were identified that directly compared sex differences in the prevalence of HAPE. No published data was found for topics other than epidemiology. Conclusions: Few studies and associated methodological limitations allow few conclusions to be drawn. Incidence of HAPE may be lower in women than in men. We speculate that besides physiological aspects, behavioral differences may contribute to this potential sex difference.
Collapse
Affiliation(s)
| | - Dominique Jean
- Paediatrics, Infectious Diseases and Altitude Medicine, Grenoble, France
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
| | - Alison J Rosier
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
| | - Mia Derstine
- Department of Emergency Medicine, University of Colorado, Aurora, Colorado, USA
| | - David Hillebrandt
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- General Medical Practitioner, Holsorthy, Devon, United Kingdom
| | - Lenka Horakova
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University Prague, Kladno, Czech Republic
| | - Linda E Keyes
- Department of Emergency Medicine, University of Colorado, Aurora, Colorado, USA
| | - Kastė Mateikaitė-Pipirienė
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Diaverum Clinics, Elektrėnai Division, Lithuania
| | - Peter Paal
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Department of Anaesthesiology and Intensive Care Medicine, St. John of God Hospital, Paracelsus Medical University, Salzburg, Austria
| | - Marija Andjelkovic
- Medical Commission of the International Climbing and Mountaineering Federation (UIAA), Bern, Switzerland
- Department of Pharmacy, Singidunum University, Belgrade, Serbia
| | - Beth A Beidlemann
- Military Performance Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Susi Kriemler
- Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland
| |
Collapse
|
8
|
Saxer S, Bader PR, Schneider SR, Mademilov M, Sheraliev U, Appenzeller P, Müller J, Sooronbaev TM, Bloch KE, Ulrich S, Lichtblau M. Echocardiography and extravascular lung water during 3 weeks of exposure to high altitude in otherwise healthy asthmatics. Front Physiol 2023; 14:1214887. [PMID: 37560159 PMCID: PMC10407397 DOI: 10.3389/fphys.2023.1214887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 07/03/2023] [Indexed: 08/11/2023] Open
Abstract
Background: Asthma rehabilitation at high altitude is common. Little is known about the acute and subacute cardiopulmonary acclimatization to high altitude in middle-aged asthmatics without other comorbidities. Methods: In this prospective study in lowlander subjects with mostly mild asthma who revealed an asthma control questionnaire score >0.75 and participated in a three-week rehabilitation program, we assessed systolic pulmonary artery pressure (sPAP), cardiac function, and extravascular lung water (EVLW) at 760 m (baseline) by Doppler-echocardiography and on the second (acute) and last day (subacute) at a high altitude clinic in Kyrgyzstan (3100 m). Results: The study included 22 patients (eight male) with a mean age of 44.3 ± 12.4 years, body mass index of 25.8 ± 4.7 kg/m2, a forced expiratory volume in 1 s of 92% ± 19% predicted (post-bronchodilator), and partially uncontrolled asthma. sPAP increased from 21.8 mmHg by mean difference by 7.5 [95% confidence interval 3.9 to 10.5] mmHg (p < 0.001) during acute exposure and by 4.8 [1.0 to 8.6] mmHg (p = 0.014) during subacute exposure. The right-ventricular-to-pulmonary-artery coupling expressed by TAPSE/sPAP decreased from 1.1 by -0.2 [-0.3 to -0.1] mm/mmHg (p < 0.001) during acute exposure and by -0.2 [-0.3 to -0.1] mm/mmHg (p = 0.002) during subacute exposure, accordingly. EVLW significantly increased from baseline (1.3 ± 1.8) to acute hypoxia (5.5 ± 3.5, p < 0.001) but showed no difference after 3 weeks (2.0 ± 1.8). Conclusion: In otherwise healthy asthmatics, acute exposure to hypoxia at high altitude increases pulmonary artery pressure (PAP) and EVLW. During subacute exposure, PAP remains increased, but EVLW returns to baseline values, suggesting compensatory mechanisms that contribute to EVLW homeostasis during acclimatization.
Collapse
Affiliation(s)
- S. Saxer
- Department of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
- Eastern University of Applied Sciences, St Gallen, Switzerland
| | - P. R. Bader
- Department of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
| | - S. R. Schneider
- Department of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
| | - M. Mademilov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - U. Sheraliev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - P. Appenzeller
- Department of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
| | - J. Müller
- Department of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
| | - T. M. Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
- Department of Respiratory Medicine, National Center for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan
| | - K. E. Bloch
- Department of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
| | - S. Ulrich
- Department of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
| | - M. Lichtblau
- Department of Pulmonology, University Hospital of Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Tuja-Ashu, Kyrgyzstan
| |
Collapse
|
9
|
Nourkami-Tutdibi N, Küllmer J, Dietrich S, Monz D, Zemlin M, Tutdibi E. Serum vascular endothelial growth factor is a potential biomarker for acute mountain sickness. Front Physiol 2023; 14:1083808. [PMID: 37064896 PMCID: PMC10098311 DOI: 10.3389/fphys.2023.1083808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Background: Acute mountain sickness (AMS) is the most common disease caused by hypobaric hypoxia (HH) in high-altitude (HA) associated with high mortality when progressing to high-altitude pulmonary edema (HAPE) and/or high-altitude cerebral edema (HACE). There is evidence for a role of pro- and anti-inflammatory cytokines in development of AMS, but biological pathways and molecular mechanisms underlying AMS remain elusive. We aimed to measure changes in blood cytokine levels and their possible association with the development of AMS.Method: 15 healthy mountaineers were included into this prospective clinical trial. All participants underwent baseline normoxic testing with venous EDTA blood sampling at the Bangor University in United Kingdom (69 m). The participants started from Beni at an altitude of 869 m and trekked same routes in four groups the Dhaulagiri circuit in the Nepali Himalaya. Trekking a 14-day route, the mountaineers reached the final HA of 5,050 m at the Hidden Valley Base Camp (HVBC). Venous EDTA blood sampling was performed after active ascent to HA the following morning after arrival at 5,050 m (HVBC). A panel of 21 cytokines, chemokines and growth factors were assessed using Luminex system (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-1ra, sIL-2Rα, IFN-γ, TNF-α, MCP-1, MIP-1α, MIP-1β, IP-10, G-CSF, GM-CSF, EGF, FGF-2, VEGF, and TGF-β1).Results: There was a significant main effect for the gradual ascent from sea-level (SL) to HA on nearly all cytokines. Serum levels for TNF-α, sIL-2Rα, G-CSF, VEGF, EGF, TGF-β1, IL-8, MCP-1, MIP-1β, and IP-10 were significantly increased at HA compared to SL, whereas levels for IFN-γ and MIP-1α were significantly decreased. Serum VEGF was higher in AMS susceptible versus AMS resistant subjects (p < 0.027, main effect of AMS) and increased after ascent to HA in both AMS groups (p < 0.011, main effect of HA). Serum VEGF increased more from SL values in the AMS susceptible group than in the AMS resistant group (p < 0.049, interaction effect).Conclusion: Cytokine concentrations are significantly altered in HA. Within short interval after ascent, cytokine concentrations in HH normalize to values at SL. VEGF is significantly increased in mountaineers suffering from AMS, indicating its potential role as a biomarker for AMS.
Collapse
|
10
|
Brent MB. Pharmaceutical treatment of bone loss: From animal models and drug development to future treatment strategies. Pharmacol Ther 2023; 244:108383. [PMID: 36933702 DOI: 10.1016/j.pharmthera.2023.108383] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/18/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023]
Abstract
Animal models are fundamental to advance our knowledge of the underlying pathophysiology of bone loss and to study pharmaceutical countermeasures against it. The animal model of post-menopausal osteoporosis from ovariectomy is the most widely used preclinical approach to study skeletal deterioration. However, several other animal models exist, each with unique characteristics such as bone loss from disuse, lactation, glucocorticoid excess, or exposure to hypobaric hypoxia. The present review aimed to provide a comprehensive overview of these animal models to emphasize the importance and significance of investigating bone loss and pharmaceutical countermeasures from perspectives other than post-menopausal osteoporosis only. Hence, the pathophysiology and underlying cellular mechanisms involved in the various types of bone loss are different, and this might influence which prevention and treatment strategies are the most effective. In addition, the review sought to map the current landscape of pharmaceutical countermeasures against osteoporosis with an emphasis on how drug development has changed from being driven by clinical observations and enhancement or repurposing of existing drugs to today's use of targeted anti-bodies that are the result of advanced insights into the underlying molecular mechanisms of bone formation and resorption. Moreover, new treatment combinations or repurposing opportunities of already approved drugs with a focus on dabigatran, parathyroid hormone and abaloparatide, growth hormone, inhibitors of the activin signaling pathway, acetazolamide, zoledronate, and romosozumab are discussed. Despite the considerable progress in drug development, there is still a clear need to improve treatment strategies and develop new pharmaceuticals against various types of osteoporosis. The review also highlights that new treatment indications should be explored using multiple animal models of bone loss in order to ensure a broad representation of different types of skeletal deterioration instead of mainly focusing on primary osteoporosis from post-menopausal estrogen deficiency.
Collapse
Affiliation(s)
- Mikkel Bo Brent
- Department of Biomedicine, Aarhus University, Denmark, Wilhelm Meyers Allé 3, 8000 Aarhus C, Denmark.
| |
Collapse
|
11
|
Chen M, Yi F, Qi Y, Zhao B, Zhang Z, He X, Yuan D, Jin T. Whole-exome sequencing in searching for novel variants associated with the development of high altitude pulmonary edema. Gene 2023; 870:147384. [PMID: 37001572 DOI: 10.1016/j.gene.2023.147384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 03/14/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023]
Abstract
BACKGROUND High altitude pulmonary edema (HAPE) is a high-altitude idiopathic disease with serious consequences due to hypoxia at high altitude, and there is individual genetic susceptibility. Whole-exome sequencing (WES) is an effective tool for studying the genetic etiology of HAPE and can identify potentially novel mutations that may cause protein instability and may contribute to the development of HAPE. MATERIALS AND METHODS A total of 50 unrelated HAPE patients were examined using WES, and the available bioinformatics tools were used to perform an analysis of exonic regions. Using the Phenolyzer program, disease candidate gene analysis was carried out. SIFT, PolyPhen-2, Mutation Taster, CADD, DANN, and I-Mutant software were used to assess the effects of genetic variations on protein function. RESULTS The results showed that rs368502694 (p. R1022Q) located in NOS3, rs1595850639 (p. G61S) located in MYBPC3, and rs1367895529 (p. R333H) located in ITGAV were correlated with a high risk of HAPE, and thus could be regarded as potential genetic variations associated with HAPE. CONCLUSION WES was used in this study for the first time to directly screen genetic variations related to HAPE. Notably, our study offers fresh information for the subsequent investigation into the etiology of HAPE.
Collapse
Affiliation(s)
- Mingyue Chen
- Key Laboratory of High Altitude Hypoxia Environment and Life Health, School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China
| | - Faling Yi
- Key Laboratory of High Altitude Hypoxia Environment and Life Health, School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China
| | - Yijin Qi
- Key Laboratory of High Altitude Hypoxia Environment and Life Health, School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China
| | - Beibei Zhao
- Key Laboratory of High Altitude Hypoxia Environment and Life Health, School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China
| | - Zhanhao Zhang
- Key Laboratory of High Altitude Hypoxia Environment and Life Health, School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China
| | - Xue He
- Key Laboratory of High Altitude Hypoxia Environment and Life Health, School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China
| | - Dongya Yuan
- Key Laboratory of High Altitude Hypoxia Environment and Life Health, School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China.
| | - Tianbo Jin
- Key Laboratory of High Altitude Hypoxia Environment and Life Health, School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; School of Medicine, Xizang Minzu University, Xianyang 712082, Shaanxi, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an, Shaanxi 710069, China.
| |
Collapse
|
12
|
Pasha Q, Rain M, Tasnim S, Kanipakam H, Thinlas T, Mohammad G. The Telomere-Telomerase System Is Detrimental to Health at High-Altitude. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:1935. [PMID: 36767300 PMCID: PMC9915065 DOI: 10.3390/ijerph20031935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
The hypobaric-hypoxia environment at high-altitude (HA, >2500 m) may influence DNA damage due to the production of reactive molecular species and high UV radiation. The telomere system, vital to chromosomal integrity and cellular viability, is prone to oxidative damages contributing to the severity of high-altitude disorders such as high-altitude pulmonary edema (HAPE). However, at the same time, it is suggested to sustain physical performance. This case-control study, comprising 210 HAPE-free (HAPE-f) sojourners, 183 HAPE-patients (HAPE-p) and 200 healthy highland natives (HLs) residing at ~3500 m, investigated telomere length, telomerase activity, and oxidative stress biomarkers. Fluidigm SNP genotyping screened 65 single nucleotide polymorphisms (SNPs) in 11 telomere-maintaining genes. Significance was attained at p ≤ 0.05 after adjusting for confounders and correction for multiple comparisons. Shorter telomere length, decreased telomerase activity and increased oxidative stress were observed in HAPE patients; contrarily, longer telomere length and elevated telomerase activity were observed in healthy HA natives compared to HAPE-f. Four SNPs and three haplotypes are associated with HAPE, whereas eight SNPs and nine haplotypes are associated with HA adaptation. Various gene-gene interactions and correlations between/among clinical parameters and biomarkers suggested the presence of a complex interplay underlining HAPE and HA adaptation physiology. A distinctive contribution of the telomere-telomerase system contributing to HA physiology is evident in this study. A normal telomere system may be advantageous in endurance training.
Collapse
Affiliation(s)
- Qadar Pasha
- Council of Scientific & Industrial Research-Institute of Genomics and Integrative Biology, New Delhi 110007, India
- Institute of Hypoxia Research, New Delhi 110067, India
| | - Manjari Rain
- Council of Scientific & Industrial Research-Institute of Genomics and Integrative Biology, New Delhi 110007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
| | - Sana Tasnim
- Council of Scientific & Industrial Research-Institute of Genomics and Integrative Biology, New Delhi 110007, India
| | - Hema Kanipakam
- Council of Scientific & Industrial Research-Institute of Genomics and Integrative Biology, New Delhi 110007, India
| | - Tashi Thinlas
- Department of Medicine, Sonam Norboo Memorial Hospital, Leh 194101, Ladakh, India
| | - Ghulam Mohammad
- Department of Medicine, Sonam Norboo Memorial Hospital, Leh 194101, Ladakh, India
| |
Collapse
|
13
|
Sanou AZ, Murray RL, Hernandez E, Sherrier D. An Unusual Presentation of Pulmonary Edema During an Ice Dive at Altitude. Mil Med 2023; 188:392-397. [PMID: 35390155 DOI: 10.1093/milmed/usac081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/03/2022] [Accepted: 03/16/2022] [Indexed: 01/11/2023] Open
Abstract
Military diving operations occur in a wide range of austere environments, including high-altitude environments and cold weather environments; however, rarely do both conditions combine. Ice diving at altitude combines the physiologic risks of diving, a hypothermic environment, and a high-altitude environment all in one. Careful planning and consideration of the potential injuries and disease processes affiliated with the aforementioned physiologic risks must be considered. In this case report, we describe a Navy diver who became obtunded secondary to hypoxia during an ice dive at 2,987 m (9,800 ft) elevation and was subsequently diagnosed with high-altitude pulmonary edema. Further consideration of the environment, activities, and history does not make this a clear case, and swimming-induced pulmonary edema which physiologically possesses many overlaps with high-altitude pulmonary edema may have contributed or been the ultimate causal factor for the diver's acute response.
Collapse
Affiliation(s)
- Aliye Z Sanou
- Force Surgeon's Office, Unit 35605, III Marine Expeditionary Force, FPO, AP 96382-5605, USA
| | - Robert L Murray
- Force Surgeon's Office, Unit 35605, III Marine Expeditionary Force, FPO, AP 96382-5605, USA.,Uniformed Services University, Bethesda, MD 20814, USA
| | - Eli Hernandez
- Surface Warfare Medical Institute, San Diego, CA 92134, USA
| | - David Sherrier
- Navy Experimental Dive Unit, Panama City Beach, FL 32407, USA
| |
Collapse
|
14
|
Tannheimer M, Lechner R. Initial Treatment of High-Altitude Pulmonary Edema: Comparison of Oxygen and Auto-PEEP. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:16185. [PMID: 36498257 PMCID: PMC9737163 DOI: 10.3390/ijerph192316185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 11/27/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Improvement of oxygenation is the aim in the therapy of high-altitude pulmonary edema (HAPE). However, descent is often difficult and hyperbaric chambers, as well as bottled oxygen, are often not available. We compare Auto-PEEP (AP-Pat), a special kind of pursed lips breathing, against the application of bottled oxygen (O2-Pat) in two patients suffering from HAPE. METHODS We compare the effect of these two different therapies on oxygen saturation measured by pulse oximetry (SpO2) over time. RESULT In both patients SpO2 increased significantly from 65-70% to 95%. Above 80% this increase was slower in AP-Pat compared with O2-Pat. Therapy started immediately in AP-Pat but was delayed in O2-Pat because of organizational and logistic reasons. CONCLUSIONS The well-established therapies of HAPE are always the option of choice, if available, and should be started as soon as possible. The advantage of Auto-PEEP is its all-time availability. It improves SpO2 nearly as well as 3 L/min oxygen and furthermore has a positive effect on oxygenation lasting for approximately 120 min after stopping. Auto-PEEP treatment does not appear inferior to oxygen treatment, at least in this cross-case comparison. Its immediate application after diagnosis probably plays an important role here.
Collapse
Affiliation(s)
- Markus Tannheimer
- Department of Sport and Rehabilitation Medicine, University of Ulm, Leimgrubenweg 14, 89075 Ulm, Germany
- Department of General and Visceral Surgery, Krankenhaus Blaubeuren, Ulmer Straße 26, 89143 Blaubeuren, Germany
| | - Raimund Lechner
- Department of Anesthesiology, Intensive Care, Emergency Medicine and Pain Therapy, Bundeswehr Hospital Ulm, Oberer Eselsberg 40, 89081 Ulm, Germany
| |
Collapse
|
15
|
Garcia SM, Matheson B, Morales-Loredo JH, Jernigan NL, Kanagy NL, Resta TC, Clark RM, Shekarriz R, Gonzalez Bosc LV. Hydrogen sulfide and miR21 are suitable biomarkers of hypoxic exposure. Am J Physiol Regul Integr Comp Physiol 2022; 323:R900-R909. [PMID: 36250874 PMCID: PMC9678419 DOI: 10.1152/ajpregu.00199.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/12/2022] [Accepted: 10/13/2022] [Indexed: 11/22/2022]
Abstract
Hypoxia is the reduction of alveolar partial pressure of oxygen ([Formula: see text]). Military members and people who practice recreational activities from moderate to high altitudes are at risk for hypoxic exposure. Hypoxemia's signs and symptoms vary from asymptomatic to severe responses, such as excessive hypoxic ventilatory responses and residual neurobehavioral impairment. Therefore, it is essential to identify hypoxia-induced biomarkers to indicate people with exposure to hypoxia. Advances have been made in understanding physiological responses to hypoxia, including elevations in circulating levels of endothelin 1 (ET-1) and microRNA 21 (miR-21) and reduction in circulating levels of hydrogen sulfide (H2S). Although the levels of these factors change upon exposure to hypoxia, it is unclear if these changes are sustained on return to normoxia. We hypothesize that hypoxia-induced ET-1 and miR-21 remain elevated, whereas hypoxia-reduction in H2S sustains after returning to normoxic conditions. To test this hypothesis, we exposed male rats to 6 h of 12% O2 and measured circulating levels of ET-1 and miR-21, pre, during, and posthypoxia. We found that ET-1 plasma levels increased in response to hypoxia but returned to normal levels within 30 min after the restoration of normoxia. miR-21 plasma levels and transdermal H2S emissions decreased in response to hypoxia, remaining decreased on return to normoxia, thus following the biomarker criteria. Therefore, this study supports a unique role for plasma miR21 and transdermal H2S as hypoxia biomarkers that could be used to identify individuals after exposure to hypoxia.
Collapse
Affiliation(s)
- Selina M Garcia
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Benjamin Matheson
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Juan H Morales-Loredo
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nancy L Kanagy
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Ross M Clark
- Department of Surgery, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | | | - Laura V Gonzalez Bosc
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| |
Collapse
|
16
|
Tetzlaff K, Swenson ER, Bärtsch P. An update on environment-induced pulmonary edema – “When the lungs leak under water and in thin air”. Front Physiol 2022; 13:1007316. [PMID: 36277204 PMCID: PMC9585243 DOI: 10.3389/fphys.2022.1007316] [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: 07/30/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
Acute pulmonary edema is a serious condition that may occur as a result of increased hydrostatic forces within the lung microvasculature or increased microvascular permeability. Heart failure or other cardiac or renal disease are common causes of cardiogenic pulmonary edema. However, pulmonary edema may even occur in young and healthy individuals when exposed to extreme environments, such as immersion in water or at high altitude. Immersion pulmonary edema (IPE) and high-altitude pulmonary edema (HAPE) share some morphological and clinical characteristics; however, their underlying mechanisms may be different. An emerging understanding of IPE indicates that an increase in pulmonary artery and capillary pressures caused by substantial redistribution of venous blood from the extremities to the chest, in combination with stimuli aggravating the effects of water immersion, such as exercise and cold temperature, play an important role, distinct from hypoxia-induced vasoconstriction in high altitude pulmonary edema. This review aims at a current perspective on both IPE and HAPE, providing a comparative view of clinical presentation and pathophysiology. A particular emphasis will be on recent advances in understanding of the pathophysiology and occurrence of IPE with a future perspective on remaining research needs.
Collapse
Affiliation(s)
- Kay Tetzlaff
- Medical Clinic, Department of Sports Medicine, University of Tübingen, Tübingen, Germany
- *Correspondence: Kay Tetzlaff,
| | - Erik R. Swenson
- Department of Medicine, University of Washington, Seattle, WA, United States
- Division of Pulmonary Medicine and Critical Care, University of Washington, Seattle, WA, United States
| | - Peter Bärtsch
- Department of Internal Medicine, University of Heidelberg, Heidelberg, Germany
| |
Collapse
|
17
|
Velasquez-Mao AJ, Velasquez M, Vandsburger MH. Cyclical depressurization degranulates platelets in an agonist-free mechanism of platelet activation. PLoS One 2022; 17:e0274178. [PMID: 36107866 PMCID: PMC9477271 DOI: 10.1371/journal.pone.0274178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 08/24/2022] [Indexed: 11/18/2022] Open
Abstract
Activation of circulating platelets by receptor binding and subsequent coagulation events are defined by a well characterized physiological response. However, the growing prevalence of chronic kidney disease (CKD) and implication of platelet-released factors in worsening cardiovascular outcomes with hemodialysis warrant further investigation into the mechanobiology of platelet degranulation. The significant drops in pressure caused by high friction across the hemodialysis flow circuit present an overlooked platelet stimulant not involving immobilization as a driver for cytoskeletal rearrangement. In this study, platelets from healthy and dialysis (pre- and post-treatment) donors were cyclically depressurized in static suspension to measure changes in physiology by integrin αIIbβ3 activation and surface P-selectin expression. The progressive increase in CD62P with no changes in PAC1 over pressure-cycling duration regardless of uremia signifies that hydrostatic depressurization involves a novel agonist-free mechanism leading to platelet degranulation as a unique case in which CD62P and PAC1 do not interchangeably indicate platelet activation. Subsequent stimulation using ADP further suggests that sustained depressurization regimens desensitize integrin αIIbβ3 activation. Variability in platelet response caused by uremia and CKD are observed by elevated baseline PAC1 in pre-dialysis samples, PAC1 retention after ADP exposure, and maximum CD62P with ADP independent of pressure. Theory for hydrostatic pressure-induced degranulation circumventing integrin-initiated signal transduction is here presented based on the Starling Equation.
Collapse
Affiliation(s)
- Aaron J. Velasquez-Mao
- UC Berkeley–UCSF Graduate Program in Bioengineering, Berkeley, CA, United States of America
| | - Mark Velasquez
- Department of Bioengineering, UC Berkeley, Berkeley, CA, United States of America
| | | |
Collapse
|
18
|
Palmo T, Abbasi BA, Chanana N, Sharma K, Faruq M, Thinlas T, Abdin MZ, Pasha Q. The EDN1 Missense Variant rs5370 G > T Regulates Adaptation and Maladaptation under Hypobaric Hypoxia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:11174. [PMID: 36141455 PMCID: PMC9517604 DOI: 10.3390/ijerph191811174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/28/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
Endothelin 1 (EDN1) encodes a potent endogenous vasoconstrictor, ET1, to maintain vascular homeostasis and redistribution of tissue blood flow during exercise. One of the EDN1 missense polymorphisms, rs5370 G/T, has strongly been associated with cardiopulmonary diseases. This study investigated the impact of rs5370 polymorphism in high-altitude pulmonary oedema (HAPE) disorder or maladaptation and adaptation physiology in a well-characterized case-control study of high-altitude and low-altitude populations comprising 310 samples each of HAPE-patients, HAPE-free controls and native highlanders. The rs5370 polymorphism was genotyped, and the gene expression and plasma level of EDN1 were evaluated. The functional relevance of each allele was investigated in the human embryonic kidney 293 cell line after exposure to hypoxia and computationally. The T allele was significantly more prevalent in HAPE-p compared to HAPE-f and HLs. The EDN1 gene expression and ET1 bio-level were significantly elevated in HAPE-p compared to controls. Compared to the G allele, the T allele was significantly associated with elevated levels of ET-1 in all three study groups and cells exposed to hypoxia. The in silico studies further confirmed the stabilizing effect of the T allele on the structural integrity and function of ET1 protein. The ET1 rs5370 T allele is associated with an increased concentration of ET-1 in vivo and in vitro, establishing it as a potent marker in the adaptation/maladaptation physiology under the high-altitude environment. This could also be pertinent in endurance exercises at high altitudes.
Collapse
Affiliation(s)
- Tsering Palmo
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
- Department of Biotechnology, Jamia Hamdard, New Delhi 110062, India
| | - Bilal Ahmed Abbasi
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Neha Chanana
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Kavita Sharma
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Mohammed Faruq
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Tashi Thinlas
- Sonam Norboo Memorial Hospital, Leh 194101, Ladakh, India
| | - Malik Z. Abdin
- Department of Biotechnology, Jamia Hamdard, New Delhi 110062, India
| | - Qadar Pasha
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi 110007, India
- Institute of Hypoxia Research, New Delhi 110067, India
| |
Collapse
|
19
|
Yu JJ, Non AL, Heinrich EC, Gu W, Alcock J, Moya EA, Lawrence ES, Tift MS, O'Brien KA, Storz JF, Signore AV, Khudyakov JI, Milsom WK, Wilson SM, Beall CM, Villafuerte FC, Stobdan T, Julian CG, Moore LG, Fuster MM, Stokes JA, Milner R, West JB, Zhang J, Shyy JY, Childebayeva A, Vázquez-Medina JP, Pham LV, Mesarwi OA, Hall JE, Cheviron ZA, Sieker J, Blood AB, Yuan JX, Scott GR, Rana BK, Ponganis PJ, Malhotra A, Powell FL, Simonson TS. Time Domains of Hypoxia Responses and -Omics Insights. Front Physiol 2022; 13:885295. [PMID: 36035495 PMCID: PMC9400701 DOI: 10.3389/fphys.2022.885295] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023] Open
Abstract
The ability to respond rapidly to changes in oxygen tension is critical for many forms of life. Challenges to oxygen homeostasis, specifically in the contexts of evolutionary biology and biomedicine, provide important insights into mechanisms of hypoxia adaptation and tolerance. Here we synthesize findings across varying time domains of hypoxia in terms of oxygen delivery, ranging from early animal to modern human evolution and examine the potential impacts of environmental and clinical challenges through emerging multi-omics approaches. We discuss how diverse animal species have adapted to hypoxic environments, how humans vary in their responses to hypoxia (i.e., in the context of high-altitude exposure, cardiopulmonary disease, and sleep apnea), and how findings from each of these fields inform the other and lead to promising new directions in basic and clinical hypoxia research.
Collapse
Affiliation(s)
- James J. Yu
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Amy L. Non
- Department of Anthropology, Division of Social Sciences, University of California, San Diego, La Jolla, CA, United States,*Correspondence: Amy L. Non, Tatum S. Simonson,
| | - Erica C. Heinrich
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, United States
| | - Wanjun Gu
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,Herbert Wertheim School of Public Health and Longevity Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Joe Alcock
- Department of Emergency Medicine, University of New Mexico, Albuquerque, MX, United States
| | - Esteban A. Moya
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Elijah S. Lawrence
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Michael S. Tift
- Department of Biology and Marine Biology, College of Arts and Sciences, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Katie A. O'Brien
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,Department of Physiology, Development and Neuroscience, Faculty of Biology, School of Biological Sciences, University of Cambridge, Cambridge, ENG, United Kingdom
| | - Jay F. Storz
- School of Biological Sciences, College of Arts and Sciences, University of Nebraska-Lincoln, Lincoln, IL, United States
| | - Anthony V. Signore
- School of Biological Sciences, College of Arts and Sciences, University of Nebraska-Lincoln, Lincoln, IL, United States
| | - Jane I. Khudyakov
- Department of Biological Sciences, University of the Pacific, Stockton, CA, United States
| | | | - Sean M. Wilson
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda, CA, United States
| | | | | | | | - Colleen G. Julian
- School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Lorna G. Moore
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, Aurora, CO, United States
| | - Mark M. Fuster
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Jennifer A. Stokes
- Department of Kinesiology, Southwestern University, Georgetown, TX, United States
| | - Richard Milner
- San Diego Biomedical Research Institute, San Diego, CA, United States
| | - John B. West
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Jiao Zhang
- Department of Medicine, UC San Diego School of Medicine, San Diego, CA, United States
| | - John Y. Shyy
- Department of Medicine, UC San Diego School of Medicine, San Diego, CA, United States
| | - Ainash Childebayeva
- Department of Archaeogenetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - José Pablo Vázquez-Medina
- Department of Integrative Biology, College of Letters and Science, University of California, Berkeley, Berkeley, CA, United States
| | - Luu V. Pham
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, Johns Hopkins Medicine, Baltimore, MD, United States
| | - Omar A. Mesarwi
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - James E. Hall
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Zachary A. Cheviron
- Division of Biological Sciences, College of Humanities and Sciences, University of Montana, Missoula, MT, United States
| | - Jeremy Sieker
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Arlin B. Blood
- Department of Pediatrics Division of Neonatology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Jason X. Yuan
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Graham R. Scott
- Department of Pediatrics Division of Neonatology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Brinda K. Rana
- Moores Cancer Center, UC San Diego, La Jolla, CA, United States,Department of Psychiatry, UC San Diego, La Jolla, CA, United States
| | - Paul J. Ponganis
- Center for Marine Biotechnology and Biomedicine, La Jolla, CA, United States
| | - Atul Malhotra
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Frank L. Powell
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Tatum S. Simonson
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, United States,*Correspondence: Amy L. Non, Tatum S. Simonson,
| |
Collapse
|
20
|
Jin T, Lu H, Zhang Z, Wang Y, Yang W, Wang Y, He X, Yuan D, He Y. CYP2S1 gene methylation among High-altitude pulmonary edema. Gene X 2022; 834:146590. [PMID: 35623478 DOI: 10.1016/j.gene.2022.146590] [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: 11/17/2021] [Revised: 03/12/2022] [Accepted: 05/16/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND High altitude pulmonary edema (HAPE) is a fatal disease of fluid accumulation in the lungs resulting from acute exposure to high altitude and hypoxia. Now research has found that changes in DNA methylation are genetically related. We investigated the effects of hypermethylation and hypomethylation on HAPE. METHODS We conducted an analysis of methylation in Chinese HAPE patients (53 patients and 53 controls). EpiTYPER of the Sequenom MassARRAY platform was used to detect DNA methylation at 43 CpG sites in CYP2S1. RESULTS We used probability analysis to find that only five CPG sites were not methylated. CYP2S1_1_CpG_11, CYP2S1_2_CpG_11, CYP2S1_2_CpG_12, CYP2S1_2_CpG_13, and CYP2S1_3_CPG_11.12 in the case group were lower than those in the control group. Our results showed that, 12 CpG sites had different methylation levels in HAPE patients compared with healthy controls, and only CYP2S1_1_CPG_1.2.3 (OR = 2.920, 95 %Cl = 1.228-6.946, p = 0.015) had a higher risk of hypermethylation than hypomethylation. ROC curve analysis showed that the methylation level of CYP2S1 could effectively predict the risk of HAPE patients. CONCLUSION Our results showed that several CpG sites in the promoter regions of CYP2S1 gene were abnormally methylated in HAPE patients.
Collapse
Affiliation(s)
- Tianbo Jin
- Key Laboratory of Molecular Mechanism and Intervention Research for Plateau Diseases of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xianyang, Shaanxi 712082, China; School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China; Engineering Research Center of Tibetan Medicine Detection Technology, Ministry of Education, China
| | - Hongyan Lu
- School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China
| | - Zhanhao Zhang
- School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China
| | - Yuliang Wang
- School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China
| | - Wei Yang
- Key Laboratory of Molecular Mechanism and Intervention Research for Plateau Diseases of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xianyang, Shaanxi 712082, China; School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China; Department of Emergency, The Affiliated Hospital of Xizang Minzu University, Xianyang, Shaanxi 712082, China
| | - Yuhe Wang
- Key Laboratory of Molecular Mechanism and Intervention Research for Plateau Diseases of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xianyang, Shaanxi 712082, China; School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China; Department of Clinical Laboratory, the Affiliated Hospital of Xizang Minzu University, Xianyang, Shaanxi 712082, China
| | - Xue He
- Key Laboratory of Molecular Mechanism and Intervention Research for Plateau Diseases of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xianyang, Shaanxi 712082, China; School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China; Engineering Research Center of Tibetan Medicine Detection Technology, Ministry of Education, China
| | - Dongya Yuan
- Key Laboratory of Molecular Mechanism and Intervention Research for Plateau Diseases of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xianyang, Shaanxi 712082, China; School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China; Engineering Research Center of Tibetan Medicine Detection Technology, Ministry of Education, China
| | - Yongjun He
- Key Laboratory of Molecular Mechanism and Intervention Research for Plateau Diseases of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xianyang, Shaanxi 712082, China; School of Basic Medical Sciences, Xizang Minzu University, Xianyang, Shaanxi 712082, China; Engineering Research Center of Tibetan Medicine Detection Technology, Ministry of Education, China.
| |
Collapse
|
21
|
Relaxin does not prevent development of hypoxia-induced pulmonary edema in rats. Pflugers Arch 2022; 474:1053-1067. [PMID: 35778581 PMCID: PMC9492557 DOI: 10.1007/s00424-022-02720-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 06/06/2022] [Accepted: 06/15/2022] [Indexed: 11/29/2022]
Abstract
Acute hypoxia impairs left ventricular (LV) inotropic function and induces development of pulmonary edema (PE). Enhanced and uneven hypoxic pulmonary vasoconstriction is an important pathogenic factor of hypoxic PE. We hypothesized that the potent vasodilator relaxin might reduce hypoxic pulmonary vasoconstriction and prevent PE formation. Furthermore, as relaxin has shown beneficial effects in acute heart failure, we expected that relaxin might also improve LV inotropic function in hypoxia. Forty-two rats were exposed over 24 h to normoxia or hypoxia (10% N2 in O2). They were infused with either 0.9% NaCl solution (normoxic/hypoxic controls) or relaxin at two doses (15 and 75 μg kg−1 day−1). After 24 h, hemodynamic measurements and bronchoalveolar lavage were performed. Lung tissue was obtained for histological and immunohistochemical analyses. Hypoxic control rats presented significant depression of LV systolic pressure by 19% and of left and right ventricular contractility by about 40%. Relaxin did not prevent the hypoxic decrease in LV inotropic function, but re-increased right ventricular contractility. Moreover, hypoxia induced moderate interstitial PE and inflammation in the lung. Contrasting to our hypothesis, relaxin did not prevent hypoxia-induced pulmonary edema and inflammation. In hypoxic control rats, PE was similarly distributed in the apical and basal lung lobes. In relaxin-treated rats, PE index was 35–40% higher in the apical than in the basal lobe, which is probably due to gravity effects. We suggest that relaxin induced exaggerated vasodilation, and hence pulmonary overperfusion. In conclusion, the results show that relaxin does not prevent but rather may aggravate PE formation.
Collapse
|
22
|
Debevec T, Narang BJ, Manferdelli G, Millet GP. Premature birth: a neglected consideration for altitude adaptation. J Appl Physiol (1985) 2022; 133:975-978. [PMID: 35708701 DOI: 10.1152/japplphysiol.00201.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Tadej Debevec
- Faculty of Sport, grid.8954.0University of Ljubljana, Ljubljana, Slovenia
| | - Benjamin J Narang
- Department of Automation, Biocybernetics, and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Giorgio Manferdelli
- Institute of Sport Sciences, grid.9851.5University of Lausanne, Lausanne, Switzerland
| | | |
Collapse
|
23
|
Sharma S, Sandhir R, Ganju L, Kumar B, Singh Y. Unique mutations in mitochondrial DNA and associated pathways involved in high altitude pulmonary edema susceptibility in Indian lowlanders. J Biomol Struct Dyn 2022:1-16. [PMID: 35666092 DOI: 10.1080/07391102.2022.2081610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
High altitude pulmonary edema (HAPE) is a life threatening non-cardiogenic pulmonary edema that occurs in an otherwise healthy individuals travelling to altitude above 2500 m. Earlier studies have reported association of mutations in nuclear (nDNA) and mitochondrial DNA (mtDNA) with HAPE susceptibility. However, the molecular mechanisms involved in the pathobiology of HAPE have not been fully understood. The present study investigates the genetic predisposition to HAPE by analyzing the mtDNA mutations in HAPE susceptibles (n = 23) and acclimatized controls (n = 23) using next generation sequencing. Structural analysis of mutations was done using SWISS Model server and stability was determined using ΔΔG values. Meta-analysis of GSE52209 dataset was done to identify differentially expressed genes (DEGs) in HAPE susceptibles and acclimatized controls. Fourteen non-synonymous, conserved and pathogenic mutations were predicted using SIFT and PolyPhen scoring in protein coding genes, whereas six mutations in mt-tRNA genes showed association with HAPE (p ≤ 0.05). The structural analysis of these mutations revealed conformational changes in critical regions in Complexes I-V which are involved in subunit assembly and proton pumping activity. The protein-protein interaction network analysis of DEGs showed that HIF1α, EGLN2, EGLN3, PDK1, TFAM, PPARGC1α and NRF1 genes form highly interconnected cluster. Further, pathway enrichment analysis using DAVID revealed that "HIF-1 signaling", "oxidative phosphorylation" and "Metabolic pathways" had strong association with HAPE. Based on the findings it appears that the identified mtDNA mutations may be a potential risk factor in development of HAPE with the associated pathways providing mechanistic insight into the understanding of pathobiology of HAPE and sites for development of therapeutic targets.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Swati Sharma
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, Delhi, India.,Department of Biochemistry, Basic Medical Sciences Block II, Panjab University, Chandigarh, India
| | - Rajat Sandhir
- Department of Biochemistry, Basic Medical Sciences Block II, Panjab University, Chandigarh, India
| | - Lilly Ganju
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, Delhi, India
| | - Bhuvnesh Kumar
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, Delhi, India
| | - Yamini Singh
- Defence Institute of Physiology and Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, Delhi, India
| |
Collapse
|
24
|
Ortiz-Prado E, Encalada S, Mosquera J, Simbaña-Rivera K, Gomez-Barreno L, Duta D, Ochoa I, Izquierdo-Condoy JS, Vasconez E, Burgos G, Calvopiña M, Viscor G. A comparative analysis of lung function and spirometry parameters in genotype-controlled natives living at low and high altitude. BMC Pulm Med 2022; 22:100. [PMID: 35313848 PMCID: PMC8939107 DOI: 10.1186/s12890-022-01889-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 02/25/2022] [Indexed: 12/15/2022] Open
Abstract
Background The reference values for lung function are associated to anatomical and lung morphology parameters, but anthropometry it is not the only influencing factor: altitude and genetics are two important agents affecting respiratory physiology. Altitude and its influence on respiratory function has been studied independently of genetics, considering early and long-term acclimatization. Objective The objective of this study is to evaluate lung function through a spirometry study in autochthonous Kichwas permanently living at low and high-altitude. Methodology A cross-sectional study of spirometry differences between genetically matched lowland Kichwas from Limoncocha (230 m) at Amazonian basin and high-altitude Kichwas from Oyacachi (3180 m) in Andean highlands. The sample size estimates permitted to recruited 118 patients (40 men and 78 women) from Limoncocha and 95 (39 men and 56 women) from Oyacachi. Chi-square method was used to analyze association or independence of categorical variables, while Student’s t test was applied to comparison of means within quantitative variables. ANOVA, or in the case that the variables didn’t meet the criteria of normality, Kruskal Wallis test were used to compare more than two groups. Results The FVC and the FEV1 were significantly greater among highlanders than lowlanders (p value < 0.001), with a proportion difference of 15.2% for men and 8.5% for women. The FEV1/FVC was significantly higher among lowlanders than highlanders for men and women. A restrictive pattern was found in 12.9% of the participants. Conclusion Residents of Oyacachi had greater FVC and FEV1 than their peers from Limoncocha, a finding physiologically plausible according to published literature. Lung size and greater ventilatory capacities could be an adaptive mechanism developed by the highlander in response to hypoxia. Our results support the fact that this difference in FVC and FEV1 is a compensatory mechanism towards lower barometric and alveolar partial pressure of oxygen pressure.
Collapse
Affiliation(s)
- Esteban Ortiz-Prado
- One Health Research Group, Faculty of Medicine, Universidad de las Américas, Calle de los Colimes y Avenida De los Granados, 170137, Quito, Ecuador. .,Department of Cell Biology, Physiology and Immunology, Universidad de Barcelona, Barcelona, Spain.
| | - Sebastián Encalada
- One Health Research Group, Faculty of Medicine, Universidad de las Américas, Calle de los Colimes y Avenida De los Granados, 170137, Quito, Ecuador
| | - Johanna Mosquera
- One Health Research Group, Faculty of Medicine, Universidad de las Américas, Calle de los Colimes y Avenida De los Granados, 170137, Quito, Ecuador
| | - Katherine Simbaña-Rivera
- One Health Research Group, Faculty of Medicine, Universidad de las Américas, Calle de los Colimes y Avenida De los Granados, 170137, Quito, Ecuador
| | - Lenin Gomez-Barreno
- One Health Research Group, Faculty of Medicine, Universidad de las Américas, Calle de los Colimes y Avenida De los Granados, 170137, Quito, Ecuador
| | - Diego Duta
- Limoncocha Community Health Unit, Limoncocha, Ecuador
| | - Israel Ochoa
- Oyacachi Community Health Unit, Oyacachi, Ecuador
| | - Juan S Izquierdo-Condoy
- One Health Research Group, Faculty of Medicine, Universidad de las Américas, Calle de los Colimes y Avenida De los Granados, 170137, Quito, Ecuador
| | - Eduardo Vasconez
- One Health Research Group, Faculty of Medicine, Universidad de las Américas, Calle de los Colimes y Avenida De los Granados, 170137, Quito, Ecuador
| | - German Burgos
- Faculty of Medicine, Universidad de las Américas, Quito, Ecuador
| | - Manuel Calvopiña
- One Health Research Group, Faculty of Medicine, Universidad de las Américas, Calle de los Colimes y Avenida De los Granados, 170137, Quito, Ecuador
| | - Ginés Viscor
- Department of Cell Biology, Physiology and Immunology, Universidad de Barcelona, Barcelona, Spain
| |
Collapse
|
25
|
Carta AF, Lichtblau M, Berlier C, Saxer S, Schneider SR, Schwarz EI, Furian M, Bloch KE, Ulrich S. The Impact of Breathing Hypoxic Gas and Oxygen on Pulmonary Hemodynamics in Patients With Pulmonary Hypertension. Front Med (Lausanne) 2022; 9:791423. [PMID: 35223898 PMCID: PMC8878983 DOI: 10.3389/fmed.2022.791423] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 01/10/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundPure oxygen breathing (hyperoxia) may improve hemodynamics in patients with pulmonary hypertension (PH) and allows to calculate right-to-left shunt fraction (Qs/Qt), whereas breathing normobaric hypoxia may accelerate hypoxic pulmonary vasoconstriction (HPV). This study investigates how hyperoxia and hypoxia affect mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with PH and whether Qs/Qt influences the changes of mPAP and PVR.Study Design and MethodsAdults with pulmonary arterial or chronic thromboembolic PH (PAH/CTEPH) underwent repetitive hemodynamic and blood gas measurements during right heart catheterization (RHC) under normoxia [fractions of inspiratory oxygen (FiO2) 0.21], hypoxia (FiO2 0.15), and hyperoxia (FiO2 1.0) for at least 10 min.ResultsWe included 149 patients (79/70 PAH/CTEPH, 59% women, mean ± SD 60 ± 17 years). Multivariable regressions (mean change, CI) showed that hypoxia did not affect mPAP and cardiac index, but increased PVR [0.4 (0.1–0.7) WU, p = 0.021] due to decreased pulmonary artery wedge pressure [−0.54 (−0.92 to −0.162), p = 0.005]. Hyperoxia significantly decreased mPAP [−4.4 (−5.5 to −3.3) mmHg, p < 0.001] and PVR [−0.4 (−0.7 to −0.1) WU, p = 0.006] compared with normoxia. The Qs/Qt (14 ± 6%) was >10 in 75% of subjects but changes of mPAP and PVR under hyperoxia and hypoxia were independent of Qs/Qt.ConclusionAcute exposure to hypoxia did not relevantly alter pulmonary hemodynamics indicating a blunted HPV-response in PH. In contrast, hyperoxia remarkably reduced mPAP and PVR, indicating a preserved vasodilator response to oxygen and possibly supporting the oxygen therapy in patients with PH. A high proportion of patients with PH showed increased Qs/Qt, which, however, was not associated with changes in pulmonary hemodynamics in response to changes in FiO2.
Collapse
|
26
|
Bebic Z, Brooks Peterson M, Polaner DM. Respiratory physiology at high altitude and considerations for pediatric patients. Paediatr Anaesth 2022; 32:118-125. [PMID: 34919777 DOI: 10.1111/pan.14380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/29/2022]
Abstract
Over 150 million people, including many children, live at high altitude (>2500 m) with the majority residing in Asia and South America. With increases in elevation, the partial pressure of oxygen (pO2) is reduced, resulting in a hypobaric hypoxic environment. Fortunately, humans have evolved adaptive processes which serve to acclimate the body to such conditions. These mechanisms, occurring along a specific time course, result in tachypnea, tachycardia, diuresis, and hematopoiesis, and a shift in the oxygen dissociation curve favoring an increased affinity for oxygen. These, along with other physiological effects, including increased pulmonary vascular resistance, alterations in cerebral blood flow, and changes in sensitivity to opioids, must be considered when administering anesthesia at high altitudes. Susceptible individuals or those who ascend too quickly may outpace the body's ability to acclimate resulting in one or more forms of high-altitude sickness ranging from the milder acute mountain sickness to the more serious conditions of high-altitude pulmonary edema and cerebral edema, either of which can be life-threatening if not promptly recognized and treated. Since the adaptive mechanisms for acclimatization greatly affect the cardiopulmonary systems, patients with underlying health issues such as sleep apnea, congenital heart disease, and asthma may have susceptibilities and warrant special consideration. Clinicians should have an understanding of the physiologic adaptations, anesthetic considerations, and special concerns in these populations in order to offer the best care possible.
Collapse
Affiliation(s)
- Zvonimir Bebic
- Department of Anesthesiology, University of Colorado/Children's Hospital Colorado, Aurora, Colorado, USA
| | - Melissa Brooks Peterson
- Department of Anesthesiology, University of Colorado/Children's Hospital Colorado, Aurora, Colorado, USA
| | - David M Polaner
- Children's Hospital, University of Washington School of Medicine, Seattle, Washington, USA
| |
Collapse
|
27
|
Affiliation(s)
- Andrew M Luks
- From the Division of Pulmonary, Critical Care, and Sleep Medicine, University of Washington, Seattle (A.M.L.); and the Altitude Research Center, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora (P.H.H.)
| | - Peter H Hackett
- From the Division of Pulmonary, Critical Care, and Sleep Medicine, University of Washington, Seattle (A.M.L.); and the Altitude Research Center, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora (P.H.H.)
| |
Collapse
|
28
|
Gasser B, Stouder J. Rescue Emergencies Due to High-Altitude Illnesses Are Rare in Switzerland. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19020865. [PMID: 35055685 PMCID: PMC8776185 DOI: 10.3390/ijerph19020865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/31/2021] [Accepted: 01/10/2022] [Indexed: 02/04/2023]
Abstract
Background: Despite a potential high risk of acute mountain sickness (AMS) in the Swiss Alps, there is a lack of analyses concerning its relevance over longer periods. In consequence, the aim of this study is to analyze the prevalence of AMS in comparison to other causes of mountain emergencies in recent years in Switzerland. Material and Methods: Based on the central registry of mountain emergencies of the Swiss Alpine Club (SAC), all cases in the period between 2009 and 2020 were analyzed for AMS including the most severe forms of high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE). Emergencies were assessed for the severity of the event with a National Advisory Committee for Aeronautics (NACA) score. Results: From a total of 4596 high-altitude mountaineering emergencies identified in the observational period, a total number of 352 cases of illnesses were detected. Detailed analysis revealed 85 cases of AMS, 5 cases of HAPE, and 1 case of HACE. The average altitude was 3845 ± 540 m. Most cases were in the canton of Valais, especially in the Monte Rosa region and the mountains of the Mischabel group (Täschhorn, Dom, Südlenz, Nadelhorn, Hohberghorn). There were only three deaths related to high-altitude illnesses; all the other events could be identified as moderate to severe but not life-threatening. Discussion: An emergency due to AMS that requires rescue is unlikely in the Swiss Alps. This does not imply that AMS is not a concern. However, the facts that the maximal altitude is relatively low and that fast self-descents often seem possible probably minimize the likelihood that mountaineers with symptoms contact emergency services.
Collapse
|
29
|
Brent MB. A review of the skeletal effects of exposure to high altitude and potential mechanisms for hypobaric hypoxia-induced bone loss. Bone 2022; 154:116258. [PMID: 34781048 DOI: 10.1016/j.bone.2021.116258] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 12/20/2022]
Abstract
Mountaineering and exposure to high altitude result in physiological adaptations to the reduced inspiratory oxygen availability. Acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) are well-described harmful effects of exposure to high altitude. Common to AMS, HAPE, and HACE are distinct clinical signs and symptoms of impaired function. However, several studies have suggested that high altitude might result in a substantial bone loss, which usually does not produce any apparent symptoms. This review aims to provide a comprehensive overview of, and map current knowledge of the skeletal effects of hypobaric hypoxia and high altitude. PubMed and Embase were searched from inception to September 6, 2021, to identify studies investigating the skeletal effects of exposure to hypobaric hypoxia and high altitude. Three hundred sixty titles and abstracts were screened, and 20 full-text articles were included (16 in vivo studies and four real-world human studies). In rodents, simulated high altitude up to 2900 m did not result in any adverse skeletal effects. In contrast, studies exposing animals to very high altitude (3500-5500 m) reported substantial reductions in BMD, cortical morphology, and bone strength, as well as deteriorated trabecular microstructure. Detrimental microstructural effects were also reported in rats exposed to simulated extreme altitude (6000 m). Finally, real-world human studies in mountaineers suggested high altitude exposure reduced bone mineral density (BMD) and that the harmful skeletal effects of hypobaric hypoxia were not entirely recovered after 12 months. In conclusion, in vivo and real-world studies demonstrated high altitude exposure results in adverse skeletal effects. The underlying mechanism for hypobaric hypoxia-induced bone loss is not elucidated.
Collapse
Affiliation(s)
- Mikkel Bo Brent
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
| |
Collapse
|
30
|
Debevec T, Poussel M, Osredkar D, Willis SJ, Sartori C, Millet GP. Post-exercise accumulation of interstitial lung water is greater in hypobaric than normobaric hypoxia in adults born prematurely. Respir Physiol Neurobiol 2021; 297:103828. [PMID: 34890833 DOI: 10.1016/j.resp.2021.103828] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 11/24/2021] [Accepted: 12/05/2021] [Indexed: 10/19/2022]
Abstract
We aimed to gauge the interstitial lung water accumulation following moderate-intensity exercise under normobaric and hypobaric hypoxic conditions in a group of preterm born but otherwise healthy young adults. Sixteen pre-term-born individuals (age = 21±2yrs.; gestational age = 29±3wk.; birth weight = 1160±273 g) underwent two 8 -h hypoxic/altitude exposures in a cross-over manner: 1) Normobaric hypoxic exposure (NH; FIO2 = 0.142±0.001; PIO2 = 90.6±0.9 mmHg) 2) Hypobaric hypoxic exposure (HH; terrestrial high-altitude 3840 m; PIO2 = 90.2±0.5 mmHg). Interstitial lung water was assessed via quantification of B-Lines (using lung ultrasound) before (normoxia) and after 4-h and 8-h of respective exposures. At each time point, B-Lines were quantified before (Pre) and immediately after (Post) a 6-min moderate-intensity exercise. The baseline B-lines count were comparable between both conditions (P = 0.191). A higher B-lines count was noted at Pre-H4 in HH versus NH (P = 0.0420). At Post-H8 B-lines score was significantly higher in HH (4.6 ± 1.6) than in NH (3.1 ± 1.4; P = 0.0073). Furthermore, at this time point, a significantly higher number of individuals with B-line scores ≥5 was observed in HH (n = 7) than in NH (n = 3; P = 0.0420). These findings suggest that short moderate-intensity exercise provokes a significant increase in the interstitial lung water accumulation after 8 h of exposure to terrestrial but not simulated altitude (≈3840 m) in prematurely born adults. Further work is needed to elucidate the exact mechanisms of (moderate-intensity) exercise-induced interstitial lung water accumulation in this population and directly compare the obtained data to full-term born adults.
Collapse
Affiliation(s)
- Tadej Debevec
- Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia; Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.
| | - Mathias Poussel
- Department of Pulmonary Function Testing and Exercise Physiology, CHRU de Nancy, Nancy, France; Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Damjan Osredkar
- Department of Pediatric Neurology, University Children's Hospital Ljubljana, Ljubljana, Slovenia
| | - Sarah J Willis
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Claudio Sartori
- Department of Internal Medicine and the Botnar Center for Extreme Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
31
|
Shimoda LA, Suresh K, Undem C, Jiang H, Yun X, Sylvester JT, Swenson ER. Acetazolamide prevents hypoxia-induced reactive oxygen species generation and calcium release in pulmonary arterial smooth muscle. Pulm Circ 2021; 11:20458940211049948. [PMID: 34646499 PMCID: PMC8504243 DOI: 10.1177/20458940211049948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 09/13/2021] [Indexed: 11/16/2022] Open
Abstract
Upon sensing a reduction in local oxygen partial pressure, pulmonary vessels constrict, a phenomenon known as hypoxic pulmonary vasoconstriction. Excessive hypoxic pulmonary vasoconstriction can occur with ascent to high altitude and is a contributing factor to the development of high-altitude pulmonary edema. The carbonic anhydrase inhibitor, acetazolamide, attenuates hypoxic pulmonary vasoconstriction through stimulation of alveolar ventilation via modulation of acid-base homeostasis and by direct effects on pulmonary vascular smooth muscle. In pulmonary arterial smooth muscle cells (PASMCs), acetazolamide prevents hypoxia-induced increases in intracellular calcium concentration ([Ca2+]i), although the exact mechanism by which this occurs is unknown. In this study, we explored the effect of acetazolamide on various calcium-handling pathways in PASMCs. Using fluorescent microscopy, we tested whether acetazolamide directly inhibited store-operated calcium entry or calcium release from the sarcoplasmic reticulum, two well-documented sources of hypoxia-induced increases in [Ca2+]i in PASMCs. Acetazolamide had no effect on calcium entry stimulated by store-depletion, nor on calcium release from the sarcoplasmic reticulum induced by either phenylephrine to activate inositol triphosphate receptors or caffeine to activate ryanodine receptors. In contrast, acetazolamide completely prevented Ca2+-release from the sarcoplasmic reticulum induced by hypoxia (4% O2). Since these results suggest the acetazolamide interferes with a mechanism upstream of the inositol triphosphate and ryanodine receptors, we also determined whether acetazolamide might prevent hypoxia-induced changes in reactive oxygen species production. Using roGFP, a ratiometric reactive oxygen species-sensitive fluorescent probe, we found that hypoxia caused a significant increase in reactive oxygen species in PASMCs that was prevented by 100 μM acetazolamide. Together, these results suggest that acetazolamide prevents hypoxia-induced changes in [Ca2+]i by attenuating reactive oxygen species production and subsequent activation of Ca2+-release from sarcoplasmic reticulum stores.
Collapse
Affiliation(s)
- Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Karthik Suresh
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Clark Undem
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Haiyang Jiang
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Xin Yun
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - J T Sylvester
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Erik R Swenson
- Division of Pulmonary and Critical Care Medicine, VA Puget Sound Health Care System and University of Washington School of Medicine, St. Louis, MO, USA
| |
Collapse
|
32
|
Rupp T, Maufrais C, Walther G, Esteve F, Macdonald JH, Bouzat P, Verges S. MEDEX 2015: Prophylactic Effects of Positive Expiratory Pressure in Trekkers at Very High Altitude. Front Physiol 2021; 12:710622. [PMID: 34621182 PMCID: PMC8490760 DOI: 10.3389/fphys.2021.710622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 08/31/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: Positive expiratory pressure (PEP) breathing has been shown to increase arterial oxygenation during acute hypoxic exposure but the underlying mechanisms and consequences on symptoms during prolonged high-altitude exposure remain to be elucidated. Methods: Twenty-four males (41 ± 16 years) were investigated, at sea level and at 5,085 m after 18 days of trekking from 570 m. Participants breathed through a face-mask with PEP = 0 cmH2O (PEP0, 0-45th min) and with PEP = 10 cmH2O (PEP10, 46-90th min). Arterial (SpO2), quadriceps and prefrontal (near infrared spectroscopy) oxygenation was measured continuously. Middle cerebral artery blood velocity (MCAv, transcranial Doppler), cardiac function (2D-echocardiography), extravascular lung water accumulation (UsLC, thoracic ultrasound lung comets) and acute mountain sickness (Lake Louise score, LLS) were assessed during PEP0 and PEP10. Results: At 5,085 m with PEP0, SpO2 was 78 ± 4%, UsLC was 8 ± 5 (a.u.) and the LLS was 2.3 ± 1.7 (all P < 0.05 versus sea level). At 5,085 m, PEP10 increased significantly SpO2 (+9 ± 5%), quadriceps (+2 ± 2%) and prefrontal cortex (+2 ± 2%) oxygenation (P < 0.05), and decreased significantly MCAv (-16 ± 14 cm.s-1) and cardiac output (-0.7 ± 1.2 L.min-1) together with a reduced stroke volume (-9 ± 15 mL, all P < 0.05) and no systemic hypotension. PEP10 decreased slightly the number of UsLC (-1.4 ± 2.7, P = 0.04) while the incidence of acute mountain sickness (LLS ≥ 3) fell from 42% with PEP0 to 25% after PEP10 (P = 0.043). Conclusion: PEP10 breathing improved arterial and tissue oxygenation and symptoms of acute mountain sickness after trekking to very high altitude, despite reduced cerebral perfusion and cardiac output. Further studies are required to establish whether PEP-breathing prophylactic mechanisms also occur in participants with more severe acute mountain sickness.
Collapse
Affiliation(s)
- Thomas Rupp
- Inter-University Laboratory of Human Movement Science (LIBM), University Savoie Mont Blanc, Chambéry, France
| | - Claire Maufrais
- Laboratoire de Pharm-Ecologie Cardiorespiratoire (LAPEC EA4278), Avignon University, Avignon, France.,HP2 Laboratory, INSERM, Grenoble Alpes University, Grenoble, France
| | - Guillaume Walther
- Laboratoire de Pharm-Ecologie Cardiorespiratoire (LAPEC EA4278), Avignon University, Avignon, France
| | - François Esteve
- RSRM EA7442, ID17-ESRF, Grenoble Alpes University, Grenoble, France
| | - Jamie Hugo Macdonald
- Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom
| | - Pierre Bouzat
- Pôle Anesthésie Réanimation, Grenoble Alpes University Hospital, Grenoble, France
| | - Samuel Verges
- HP2 Laboratory, INSERM, Grenoble Alpes University, Grenoble, France
| |
Collapse
|
33
|
Li J, Xia Y, Huang Z, Zhao Y, Xiong R, Li X, Huang Q, Shan F. Novel HIF-1-target gene isthmin1 contributes to hypoxia-induced hyperpermeability of pulmonary microvascular endothelial cells monolayers. Am J Physiol Cell Physiol 2021; 321:C671-C680. [PMID: 34469202 DOI: 10.1152/ajpcell.00124.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/19/2021] [Indexed: 11/22/2022]
Abstract
Hypoxia-induced pulmonary microvascular endothelial cell (PMVEC) monolayers hyperpermeability is vital for vascular leakage, which participates in vascular diseases, such as acute lung injury (ALI) and high-altitude pulmonary edema (HAPE). We previously observed that PMVEC permeability was markedly elevated in hypoxia when cocultured with primary type II alveolar epithelial cells (AECII) in which isthmin1 (ISM1) was highly upregulated. However, whether the upregulation of ISM1 plays a role in hypoxia-induced PMVEC hyperpermeability is unclear. In this study, we assessed the role of AECII-derived ISM1 in hypoxia-induced PMVEC hyperpermeability with an AECII/PMVEC coculture system and uncovered the underlying mechanism whereby hypoxia stimulates ISM1 gene expression. We found that ISM1 gene expression was upregulated in cultured AECII cells exposed to hypoxia (3% O2) and that AECII-derived ISM1 participated in hypoxia-induced hyperpermeability of PMVEC monolayers, as small interference RNA (siRNA)-mediated knockdown of ISM1 in AECII markedly attenuated the increase in PMVEC permeability in coculture system under hypoxia. In addition, we confirmed that ISM1 was regulated by hypoxia-inducible factor-1α (HIF1α) according to the evidence that silencing of HIF1α inhibited the hypoxia-mediated upregulation of ISM1. Mechanismly, overexpression of HIF1α transcriptionally activated ISM1 gene expression by directly binding to the conserved regulatory elements upstream of the ism1 locus. We identified a novel HIF-1-target gene ISM1, which involves in hyperpermeability of pulmonary microvascular endothelial cell monolayers under hypoxia. Our in vitro cell experiments implied that the upregulated ISM1 derived from alveolar epithelium might be a vital modulator in hypoxia-induced endothelial hyperpermeability and thereby implicates with hypoxic pulmonary-related diseases.
Collapse
Affiliation(s)
- Junxia Li
- State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, People's Republic of China
| | - Yiming Xia
- State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, People's Republic of China
| | - Zhizhong Huang
- State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, People's Republic of China
| | - Yan Zhao
- State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, People's Republic of China
| | - Renping Xiong
- State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, People's Republic of China
| | - Xiaoxu Li
- College of High Altitude Military Medicine, Army Medical University, Chongqing, People's Republic of China
| | - Qingyuan Huang
- College of High Altitude Military Medicine, Army Medical University, Chongqing, People's Republic of China
| | - Fabo Shan
- State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Army Medical University, Chongqing, People's Republic of China
| |
Collapse
|
34
|
Appelt P, Gabriel P, Bölter C, Fiedler N, Schierle K, Salameh A, Rassler B. Left ventricular depression and pulmonary edema in rats after short-term normobaric hypoxia: effects of adrenergic blockade and reduced fluid load. Pflugers Arch 2021; 473:1723-1735. [PMID: 34510286 PMCID: PMC8528748 DOI: 10.1007/s00424-021-02618-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/13/2021] [Accepted: 08/25/2021] [Indexed: 12/25/2022]
Abstract
Acute normobaric hypoxia may induce pulmonary injury with edema (PE) and inflammation. Hypoxia is accompanied by sympathetic activation. As both acute hypoxia and high plasma catecholamine levels may elicit PE, we had originally expected that adrenergic blockade may attenuate the severity of hypoxic pulmonary injury. In particular, we investigated whether administration of drugs with reduced fluid load would be beneficial with respect to both cardiocirculatory and pulmonary functions in acute hypoxia. Rats were exposed to normobaric hypoxia (10% O2) over 1.5 or 6 h and received 0.9% NaCl or adrenergic blockers either as infusion (1 ml/h, increased fluid load) or injection (0.5 ml, reduced fluid load). Control animals were kept in normoxia and received infusions or injections of 0.9% NaCl. After 6 h of hypoxia, LV inotropic function was maintained with NaCl injection but decreased significantly with NaCl infusion. Adrenergic blockade induced a similar LV depression when fluid load was low, but did not further deteriorate LV depression after 6 h of infusion. Reduced fluid load also attenuated pulmonary injury after 6 h of hypoxia. This might be due to an effective fluid drainage into the pleural space. Adrenergic blockade could not prevent PE. In general, increased fluid load and impaired LV inotropic function promote the development of PE in acute hypoxia. The main physiologic conclusion from this study is that fluid reduction under hypoxic conditions has a protective effect on cardiopulmonary function. Consequently, appropriate fluid management has particular importance to subjects in hypoxic conditions.
Collapse
Affiliation(s)
- Peter Appelt
- Carl-Ludwig-Institute of Physiology, University of Leipzig, Leipzig, Germany
| | - Philipp Gabriel
- Carl-Ludwig-Institute of Physiology, University of Leipzig, Leipzig, Germany
| | - Christian Bölter
- Carl-Ludwig-Institute of Physiology, University of Leipzig, Leipzig, Germany
| | - Nicole Fiedler
- Carl-Ludwig-Institute of Physiology, University of Leipzig, Leipzig, Germany
| | - Katrin Schierle
- Institute of Pathology, University of Leipzig, Leipzig, Germany
| | - Aida Salameh
- Department of Pediatric Cardiology, Heart Centre, University of Leipzig, Leipzig, Germany
| | - Beate Rassler
- Carl-Ludwig-Institute of Physiology, University of Leipzig, Leipzig, Germany.
| |
Collapse
|
35
|
Miglani M, Rain M, Pasha Q, Raj VS, Thinlas T, Mohammad G, Gupta A, Pandey RP, Vibhuti A. Shorter telomere length, higher telomerase activity in association with tankyrase gene polymorphism contribute to high-altitude pulmonary edema. Hum Mol Genet 2021; 29:3094-3106. [PMID: 32916703 DOI: 10.1093/hmg/ddaa205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 08/30/2020] [Accepted: 09/04/2020] [Indexed: 12/12/2022] Open
Abstract
High-altitude pulmonary edema (HAPE) is a noncardiogenic form of pulmonary edema, which is induced upon exposure to hypobaric hypoxia at high altitude (HA). Hypobaric hypoxia generates reactive oxygen species that may damage telomeres and disturb normal physiological processes. Telomere complex comprises of multiple proteins, of which, tankyrase (TNKS) is actively involved in DNA damage repairs. We hence investigated the association of TNKS and telomeres with HAPE to delineate their potential role at HA. The study was performed in three groups, High-altitude pulmonary edema patients (HAPE-p, n = 200), HAPE-resistant sojourners (HAPE-r, n = 200) and highland permanent healthy residents (HLs, n = 200). Variants of TNKS were genotyped using polymerase chain reaction-restriction fragment length polymorphism. Plasma TNKS level was estimated using enzyme-linked immunosorbent assay, expression of TNKS and relative telomere length were assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and telomerase activity was assessed by the telomere repeat amplification protocol assay. TNKS poly-ADP ribosylates the telomere-repeat factor (TRF), which is a negative regulator of telomere length. Consequently, TRF expression was also measured by RT-qPCR. The TNKS heterozygotes rs7015700GA were prevalent in HLs compared to the HAPE-p and HAPE-r. The plasma TNKS was significantly decreased in HAPE-p than HAPE-r (P = 0.006). TNKS was upregulated 9.27 folds in HAPE-p (P = 1.01E-06) and downregulated in HLs by 3.3 folds (P = 0.02). The telomere length was shorter in HAPE-p compared to HAPE-r (P = 0.03) and HLs (P = 4.25E-4). The telomerase activity was significantly higher in HAPE-p compared to both HAPE-r (P = 0.01) and HLs (P = 0.001). HAPE-p had the lowest TNKS levels (0.186 ± 0.031 ng/μl) and the highest telomerase activity (0.0268 amoles/μl). The findings of the study indicate the association of TNKS and telomeres with HA adaptation/maladaptation.
Collapse
Affiliation(s)
- Manjula Miglani
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India.,Functional Genomics Unit, Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research, Delhi, 110007, India
| | - Manjari Rain
- Functional Genomics Unit, Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research, Delhi, 110007, India
| | - Qadar Pasha
- Functional Genomics Unit, Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research, Delhi, 110007, India
| | - V Samuel Raj
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India
| | - Tashi Thinlas
- Department of Medicine, Sonam Norboo Memorial Hospital, Leh-Ladakh 194101, India
| | - Ghulam Mohammad
- Department of Medicine, Sonam Norboo Memorial Hospital, Leh-Ladakh 194101, India
| | - Archana Gupta
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India
| | - Ramendra Pati Pandey
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India
| | - Arpana Vibhuti
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India
| |
Collapse
|
36
|
Miglani M, Pasha Q, Gupta A, Priyadarshini A, Pati Pandey R, Vibhuti A. Seeding drug discovery: Telomeric tankyrase as a pharmacological target for the pathophysiology of high-altitude hypoxia. Drug Discov Today 2021; 26:2774-2781. [PMID: 34302973 DOI: 10.1016/j.drudis.2021.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 06/01/2021] [Accepted: 07/12/2021] [Indexed: 12/26/2022]
Abstract
Cellular exposure to extreme environments leads to the expression of multiple proteins that participate in pathophysiological manifestations. Hypobaric hypoxia at high altitude (HA) generates reactive oxygen species (ROS) that can damage telomeres. Tankyrase (TNKS) belongs to multiple telomeric protein complexes and is actively involved in DNA damage repair. Although published research on TNKS indicates its possible role in cancer and other hypoxic diseases, its role in HA sicknesses remains elusive. Understanding the roles of telomeres, telomerase, and TNKS could ameliorate physiological issues experienced at HA. In addition, telomeric TNKS could be a potential biomarker in hypoxia-induced sicknesses or acclimatization. Thus, a new research avenue on TNKS linked to HA sickness might lead to the discovery of drugs for hypobaric hypoxia.
Collapse
Affiliation(s)
- Manjula Miglani
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India; Functional Genomics Unit, Institute of Genomics and Integrative Biology, CSIR, Delhi 110007, India
| | - Qadar Pasha
- Functional Genomics Unit, Institute of Genomics and Integrative Biology, CSIR, Delhi 110007, India
| | - Archana Gupta
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India
| | - Anjali Priyadarshini
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India
| | - Ramendra Pati Pandey
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India
| | - Arpana Vibhuti
- Department of Biotechnology, SRM University, Delhi-NCR, Sonepat, Haryana 131029, India.
| |
Collapse
|
37
|
Zubieta-Calleja G, Zubieta-DeUrioste N. The Oxygen Transport Triad in High-Altitude Pulmonary Edema: A Perspective from the High Andes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:7619. [PMID: 34300070 PMCID: PMC8305285 DOI: 10.3390/ijerph18147619] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 12/24/2022]
Abstract
Acute high-altitude illnesses are of great concern for physicians and people traveling to high altitude. Our recent article "Acute Mountain Sickness, High-Altitude Pulmonary Edema and High-Altitude Cerebral Edema, a View from the High Andes" was questioned by some sea-level high-altitude experts. As a result of this, we answer some observations and further explain our opinion on these diseases. High-Altitude Pulmonary Edema (HAPE) can be better understood through the Oxygen Transport Triad, which involves the pneumo-dynamic pump (ventilation), the hemo-dynamic pump (heart and circulation), and hemoglobin. The two pumps are the first physiologic response upon initial exposure to hypobaric hypoxia. Hemoglobin is the balancing energy-saving time-evolving equilibrating factor. The acid-base balance must be adequately interpreted using the high-altitude Van Slyke correction factors. Pulse-oximetry measurements during breath-holding at high altitude allow for the evaluation of high altitude diseases. The Tolerance to Hypoxia Formula shows that, paradoxically, the higher the altitude, the more tolerance to hypoxia. In order to survive, all organisms adapt physiologically and optimally to the high-altitude environment, and there cannot be any "loss of adaptation". A favorable evolution in HAPE and pulmonary hypertension can result from the oxygen treatment along with other measures.
Collapse
Affiliation(s)
- Gustavo Zubieta-Calleja
- High Altitude Pulmonary and Pathology Institute (HAPPI-IPPA), Av. Copacabana Prolongacion #55, La Paz 2826, Bolivia;
| | | |
Collapse
|
38
|
Lichtblau M, Bader PR, Carta AF, Furian M, Muralt L, Saxer S, Hartmann SE, Rawling JM, Poulin MJ, Bloch KE, Ulrich S. Extravascular lung water and cardiac function assessed by echocardiography in healthy lowlanders during repeated very high-altitude exposure. Int J Cardiol 2021; 332:166-174. [PMID: 33775791 DOI: 10.1016/j.ijcard.2021.03.057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/05/2021] [Accepted: 03/22/2021] [Indexed: 12/26/2022]
Abstract
BACKGROUND High-altitude pulmonary edema is associated with elevated systolic pulmonary artery pressure (sPAP) and increased extravascular lung water (EVLW). We investigated sPAP and EVLW during repeated exposures to high altitude (HA). METHODS Healthy lowlanders underwent two identical 7-day HA-cycles, where subjects slept at 2900 m and spent 4-8 h daily at 5050 m, separated by a weeklong break at low altitude (LA). Echocardiography and EVLW by B-lines were measured at 520 m (baseline, LA1), on day one, two and six at 5050 m (HA1-3) and after descent (LA2). RESULTS We included 21 subjects (median 25 years, body mass index 22 kg/m2, SpO2 98%). SPAP rose from 21 mmHg at LA1 to 38 mmHg at HA1, decreased to 30 mmHg at HA3 (both p < 0.05 vs LA1) and normalized at 20 mmHg at LA2 (p = ns vs LA1). B-lines increased from 0 at LA1 to 6 at HA2 and 7 at HA3 (both p < 0.05 vs LA1) and receded to 1 at LA2 (p = ns vs LA1). Overall, in cycle two, sPAP did not differ (mean difference (95% confidence interval) -0.2(-2.3 to 1.9) mmHg, p = 0.864) but B-lines were more prevalent (+2.3 (1.4-3.1), p < 0.001) compared to cycle 1. Right ventricular systolic function decreased significantly but minimally at 5050 m. CONCLUSIONS Exposure to 5050 m induced a rapid increase in sPAP. B-lines rose during prolonged exposures to 5050 m, despite gradual decrease in sPAP, indicating excessive hydrostatic pressure might not be solely responsible for EVLW-development. Repeated HA-exposure had no acclimatization effect on EVLW. This may affect workers needing repetitive ascents to altitude and could indicate greater B-line development upon repeated exposure.
Collapse
Affiliation(s)
- Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.
| | - Patrick R Bader
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.
| | - Arcangelo F Carta
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.
| | - Lara Muralt
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Stéphanie Saxer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.
| | - Sara E Hartmann
- Department of Physiology and Pharmacology and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - Jean M Rawling
- Department of Family Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - Marc J Poulin
- Department of Physiology and Pharmacology and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - Konrad E Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland.
| |
Collapse
|
39
|
Pulmonary Hypertension in Acute and Chronic High Altitude Maladaptation Disorders. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18041692. [PMID: 33578749 PMCID: PMC7916528 DOI: 10.3390/ijerph18041692] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 12/13/2022]
Abstract
Alveolar hypoxia is the most prominent feature of high altitude environment with well-known consequences for the cardio-pulmonary system, including development of pulmonary hypertension. Pulmonary hypertension due to an exaggerated hypoxic pulmonary vasoconstriction contributes to high altitude pulmonary edema (HAPE), a life-threatening disorder, occurring at high altitudes in non-acclimatized healthy individuals. Despite a strong physiologic rationale for using vasodilators for prevention and treatment of HAPE, no systematic studies of their efficacy have been conducted to date. Calcium-channel blockers are currently recommended for drug prophylaxis in high-risk individuals with a clear history of recurrent HAPE based on the extensive clinical experience with nifedipine in HAPE prevention in susceptible individuals. Chronic exposure to hypoxia induces pulmonary vascular remodeling and development of pulmonary hypertension, which places an increased pressure load on the right ventricle leading to right heart failure. Further, pulmonary hypertension along with excessive erythrocytosis may complicate chronic mountain sickness, another high altitude maladaptation disorder. Importantly, other causes than hypoxia may potentially underlie and/or contribute to pulmonary hypertension at high altitude, such as chronic heart and lung diseases, thrombotic or embolic diseases. Extensive clinical experience with drugs in patients with pulmonary arterial hypertension suggests their potential for treatment of high altitude pulmonary hypertension. Small studies have demonstrated their efficacy in reducing pulmonary artery pressure in high altitude residents. However, no drugs have been approved to date for the therapy of chronic high altitude pulmonary hypertension. This work provides a literature review on the role of pulmonary hypertension in the pathogenesis of acute and chronic high altitude maladaptation disorders and summarizes current knowledge regarding potential treatment options.
Collapse
|
40
|
Park TJ, Smith ESJ, Reznick J, Bennett NC, Applegate DT, Larson J, Lewin GR. African Naked Mole-Rats Demonstrate Extreme Tolerance to Hypoxia and Hypercapnia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1319:255-269. [PMID: 34424519 DOI: 10.1007/978-3-030-65943-1_9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Naked mole-rats are extremely tolerant to low concentrations of oxygen (hypoxia) and high concentrations of carbon dioxide (hypercapnia), which is consistent with the environment that they inhabit. Naked mole-rats combine subterranean living with living in very densely populated colonies where oxygen becomes depleted and carbon dioxide accumulates. In the laboratory, naked mole-rats fully recover from 5 h exposure to 5% O2 and 5 h exposure to 80% CO2, whereas both conditions are rapidly lethal to similarly sized laboratory mice. During anoxia (0% O2) naked mole-rats enter a suspended animation-like state and switch from aerobic metabolism of glucose to anaerobic metabolism of fructose. Additional fascinating characteristics include that naked mole-rats show intrinsic brain tolerance to anoxia; a complete lack of hypoxia-induced and CO2-induced pulmonary edema; and reduced aversion to high concentrations of CO2 and acidic fumes. Here we outline a constellation of physiological and molecular adaptations that correlate with the naked mole-rat's hypoxic/hypercapnic tolerance and which offer potential targets for ameliorating pathological conditions in humans, such as the damage caused during cerebral ischemia.
Collapse
Affiliation(s)
- Thomas J Park
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA.
| | - Ewan St J Smith
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Jane Reznick
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - N C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Daniel T Applegate
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - John Larson
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| |
Collapse
|
41
|
Sánchez K, Ballaz SJ. Might a high hemoglobin mass be involved in non-cardiogenic pulmonary edema? The case of the chronic maladaptation to high-altitude in the Andes. Med Hypotheses 2020; 146:110418. [PMID: 33268002 DOI: 10.1016/j.mehy.2020.110418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 11/21/2020] [Indexed: 10/22/2022]
Abstract
Exposure to hypoxic environments when ascending at high altitudes may cause life-threatening pulmonary edema (HAPE) due to a rapid accumulation of extracellular fluid flooding in the pulmonary alveoli. In Andeans, high-altitude adaptation occurs at the expense of being more prone to chronic mountain sickness: relative hypoventilation, excess pulmonary hypertension, and secondary polycythemia. Because HAPE prevalence is high in the Andes, we posit the hypothesis that a high hemoglobine mass may increase HAPE risk. In support of it, high intrapulmonary hypertension along with hyperviscosity produced by polycytemia may enhance sear forces and intravascular hemolysis, thus leading to increased acellular hemoglobin and the subsequent damage of the alveolar and endothelial barrier. It is proposed to investigate the relationship between the vaso-endothelial homeostasis and erythropoiesis in the maladaptation to high altitude and HAPE. This research is especially important when reentry HAPE, since rheologic properties of blood changes with rapid ascent to high altitudes.
Collapse
Affiliation(s)
- Karen Sánchez
- School of Biological Sciences & Engineering. Yachay Tech University, San Miguel de Urcuquí, Ecuador
| | - Santiago J Ballaz
- School of Biological Sciences & Engineering. Yachay Tech University, San Miguel de Urcuquí, Ecuador.
| |
Collapse
|
42
|
Chanana N, Palmo T, Newman JH, Pasha MAQ. Vascular homeostasis at high-altitude: role of genetic variants and transcription factors. Pulm Circ 2020; 10:2045894020913475. [PMID: 33282179 PMCID: PMC7682230 DOI: 10.1177/2045894020913475] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/14/2020] [Indexed: 12/24/2022] Open
Abstract
High-altitude pulmonary edema occurs most frequently in non-acclimatized low landers on exposure to altitude ≥2500 m. High-altitude pulmonary edema is a complex condition that involves perturbation of signaling pathways in vasoconstrictors, vasodilators, anti-diuretics, and vascular growth factors. Genetic variations are instrumental in regulating these pathways and evidence is accumulating for a role of epigenetic modification in hypoxic responses. This review focuses on the crosstalk between high-altitude pulmonary edema-associated genetic variants and transcription factors, comparing high-altitude adapted and high-altitude pulmonary edema-afflicted subjects. This approach might ultimately yield biomarker information both to understand and to design therapies for high-altitude adaptation.
Collapse
Affiliation(s)
- Neha Chanana
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
| | - Tsering Palmo
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
| | - John H Newman
- Pulmonary Circulation Center, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - M A Qadar Pasha
- Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India.,Indian Council of Medical Research, New Delhi, India
| |
Collapse
|
43
|
Baloglu E, Nonnenmacher G, Seleninova A, Berg L, Velineni K, Ermis-Kaya E, Mairbäurl H. The role of hypoxia-induced modulation of alveolar epithelial Na +- transport in hypoxemia at high altitude. Pulm Circ 2020; 10:50-58. [PMID: 33110497 PMCID: PMC7557693 DOI: 10.1177/2045894020936662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/02/2020] [Indexed: 12/14/2022] Open
Abstract
Reabsorption of excess alveolar fluid is driven by vectorial Na+-transport across alveolar epithelium, which protects from alveolar flooding and facilitates gas exchange. Hypoxia inhibits Na+-reabsorption in cultured cells and in-vivo by decreasing activity of epithelial Na+-channels (ENaC), which impairs alveolar fluid clearance. Inhibition also occurs during in-vivo hypoxia in humans and laboratory animals. Signaling mechanisms that inhibit alveolar reabsorption are poorly understood. Because cellular adaptation to hypoxia is regulated by hypoxia-inducible transcription factors (HIF), we tested whether HIFs are involved in decreasing Na+-transport in hypoxic alveolar epithelium. Expression of HIFs was suppressed in cultured rat primary alveolar epithelial cells (AEC) with shRNAs. Hypoxia (1.5% O2, 24 h) decreased amiloride-sensitive transepithelial Na+-transport, decreased the mRNA expression of α-, β-, and γ-ENaC subunits, and reduced the amount of αβγ-ENaC subunits in the apical plasma membrane. Silencing HIF-2α partially prevented impaired fluid reabsorption in hypoxic rats and prevented the hypoxia-induced decrease in α- but not the βγ-subunits of ENaC protein expression resulting in a less active form of ENaC in hypoxic AEC. Inhibition of alveolar reabsorption also caused pulmonary vasoconstriction in ventilated rats. These results indicate that a HIF-2α-dependent decrease in Na+-transport in hypoxic alveolar epithelium decreases alveolar reabsorption. Because susceptibles to high-altitude pulmonary edema (HAPE) have decreased Na+-transport even in normoxia, inhibition of alveolar reabsorption by hypoxia at high altitude might further impair alveolar gas exchange. Thus, aggravated hypoxemia might further enhance hypoxic pulmonary vasoconstriction and might subsequently cause HAPE.
Collapse
Affiliation(s)
- Emel Baloglu
- Department of Pharmacology, Acibadem Mehmet Ali Aydinlar University, School of Medicine, Istanbul, Turkey.,Translational Lung Research Center Heidelberg (TLRC), Heidelberg, Germany
| | | | - Anna Seleninova
- Translational Lung Research Center Heidelberg (TLRC), Heidelberg, Germany
| | - Lena Berg
- Translational Lung Research Center Heidelberg (TLRC), Heidelberg, Germany
| | - Kalpana Velineni
- Translational Lung Research Center Heidelberg (TLRC), Heidelberg, Germany
| | - Ezgi Ermis-Kaya
- Translational Lung Research Center Heidelberg (TLRC), Heidelberg, Germany
| | - Heimo Mairbäurl
- Translational Lung Research Center Heidelberg (TLRC), Heidelberg, Germany.,Translational Pneumology, University Hospital Heidelberg, Heidelberg, Germany
| |
Collapse
|
44
|
COVID-19 Lung Injury and High-Altitude Pulmonary Edema. A False Equation with Dangerous Implications. Ann Am Thorac Soc 2020; 17:918-921. [PMID: 32735170 PMCID: PMC7393782 DOI: 10.1513/annalsats.202004-327cme] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Amid efforts to care for the large number of patients with coronavirus disease (COVID-19), there has been considerable speculation about whether the lung injury seen in these patients is different than acute respiratory distress syndrome from other causes. One idea that has garnered considerable attention, particularly on social media and in free open-access medicine, is the notion that lung injury due to COVID-19 is more similar to high-altitude pulmonary edema (HAPE). Drawing on this concept, it has also been proposed that treatments typically employed in the management of HAPE and other forms of acute altitude illness—pulmonary vasodilators and acetazolamide—should be considered for COVID-19. Despite some similarities in clinical features between the two entities, such as hypoxemia, radiographic opacities, and altered lung compliance, the pathophysiological mechanisms of HAPE and lung injury due to COVID-19 are fundamentally different, and the entities cannot be viewed as equivalent. Although of high utility in the management of HAPE and acute mountain sickness, systemically delivered pulmonary vasodilators and acetazolamide should not be used in the treatment of COVID-19, as they carry the risk of multiple adverse consequences, including worsened ventilation–perfusion matching, impaired carbon dioxide transport, systemic hypotension, and increased work of breathing.
Collapse
|
45
|
Zahedipour F, Hosseini SA, Sathyapalan T, Majeed M, Jamialahmadi T, Al-Rasadi K, Banach M, Sahebkar A. Potential effects of curcumin in the treatment of COVID-19 infection. Phytother Res 2020; 34:2911-2920. [PMID: 32430996 PMCID: PMC7276879 DOI: 10.1002/ptr.6738] [Citation(s) in RCA: 154] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/24/2020] [Accepted: 05/07/2020] [Indexed: 12/15/2022]
Abstract
Coronavirus disease 2019 (COVID-19) outbreak is an ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with considerable mortality worldwide. The main clinical manifestation of COVID-19 is the presence of respiratory symptoms, but some patients develop severe cardiovascular and renal complications. There is an urgency to understand the mechanism by which this virus causes complications so as to develop treatment options. Curcumin, a natural polyphenolic compound, could be a potential treatment option for patients with coronavirus disease. In this study, we review some of the potential effects of curcumin such as inhibiting the entry of virus to the cell, inhibiting encapsulation of the virus and viral protease, as well as modulating various cellular signaling pathways. This review provides a basis for further research and development of clinical applications of curcumin for the treatment of newly emerged SARS-CoV-2.
Collapse
Affiliation(s)
- Fatemeh Zahedipour
- Department of Medical Biotechnology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Seyede Atefe Hosseini
- Department of Medical Biotechnology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Thozhukat Sathyapalan
- Department of Academic Diabetes, Endocrinology and Metabolism, Hull York Medical School, University of Hull, Hull, HU3 2JZ, UK
| | | | - Tannaz Jamialahmadi
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, 9177948564, Iran.,Department of Food Science and Technology, Quchan Branch, Islamic Azad University, Quchan, Iran.,Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Khalid Al-Rasadi
- Department of Clinical Biochemistry, Sultan Qaboos University Hospital, Muscat, Oman
| | - Maciej Banach
- Department of Hypertension, WAM University Hospital in Lodz, Medical University of Lodz, Lodz, Poland.,Polish Mother's Memorial Hospital Research Institute (PMMHRI), Lodz, Poland
| | - Amirhossein Sahebkar
- Polish Mother's Memorial Hospital Research Institute (PMMHRI), Lodz, Poland.,Halal Research Center of IRI, FDA, Tehran, Iran.,Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| |
Collapse
|
46
|
Alam P, Agarwal G, Kumar R, Mishra A, Saini N, Mohammad G, Pasha MAQ. Susceptibility to high-altitude pulmonary edema is associated with circulating miRNA levels under hypobaric hypoxia conditions. Am J Physiol Lung Cell Mol Physiol 2020; 319:L360-L368. [PMID: 32692577 DOI: 10.1152/ajplung.00168.2020] [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] [Indexed: 02/02/2023] Open
Abstract
Hypobaric hypoxia poses stress to sojourners traveling to high-altitude. A cascade of physiological changes occurs to cope with or adapt to hypobaric hypoxia. However, an insufficient physiological response to the hypoxic condition resulting from imbalanced vascular homeostasis pathways results in high-altitude pulmonary edema (HAPE). The present study aims to identify the implication of miRNAs associating with HAPE and adaptation. We analyzed the expression of 1,113 miRNAs in HAPE-patients (HAPE-p), HAPE-free controls (HAPE-f), and highland natives (HLs). Based on miRNA profiling and in silico analyses, miR-124-3p emerged relevantly. We observed a significant overexpression of miR-124-3p in HAPE-p. In silico analyses revealed a direct interaction of miR-124-3p with vascular homeostasis and hypoxia-associated genes NOS3 (endothelial nitric oxide synthase), Apelin, and ETS1 (V-Ets avian erythroblastosis virus E2 oncogene homolog 1). Moreover, the transcript and biolevel expression of these genes were significantly decreased in HAPE-p when compared with HAPE-f or HLs. Our in vitro analysis in human umbilical vein endothelial cells demonstrated a significant knockdown of these genes both at transcript and protein levels following miR-124-3p overexpression. Conclusively, our results showed that miR-124-3p might play a plausible role in HAPE pathophysiology by inhibiting the expression of NOS3, Apelin, and ETS1.
Collapse
Affiliation(s)
- Perwez Alam
- Genomics and Molecular Medicine, Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India.,Department of Biotechnology, Savitribai Phule Pune University, Pune, India.,Department of Pathology and Laboratory Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Garima Agarwal
- Genomics and Molecular Medicine, Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India
| | - Rahul Kumar
- Department of Medicine, University of California San Francisco, San Francisco, California
| | - Aastha Mishra
- Genomics and Molecular Medicine, Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India.,Department of Biotechnology, Savitribai Phule Pune University, Pune, India
| | - Neeru Saini
- Genomics and Molecular Medicine, Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India
| | - Ghulam Mohammad
- Department of Medicine, Sonam Norboo Memorial Hospital, Leh, India
| | - M A Qadar Pasha
- Genomics and Molecular Medicine, Council of Scientific and Industrial Research-Institute of Genomics and Integrative Biology, Delhi, India.,Department of Biotechnology, Savitribai Phule Pune University, Pune, India
| |
Collapse
|
47
|
Gojkovic M, Darmasaputra GS, Veliça P, Rundqvist H, Johnson RS. Deregulated hypoxic response in myeloid cells: A model for high-altitude pulmonary oedema (HAPE). Acta Physiol (Oxf) 2020; 229:e13461. [PMID: 32129933 PMCID: PMC8638671 DOI: 10.1111/apha.13461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/06/2020] [Accepted: 02/25/2020] [Indexed: 12/11/2022]
Abstract
AIM High-altitude pulmonary oedema (HAPE) is a non-cardiogenic pulmonary oedema that can occur during rapid ascent to a high-altitude environment. Classically, HAPE has been described as a condition resulting from a combination of pulmonary vasoconstriction and hypertension. Inflammation has been described as important in HAPE, although as a side effect of pulmonary oedema rather than as a causative factor. In this study, we aim to understand the role of hypoxic response in myeloid cells and its involvement in pathogenesis of HAPE. METHODS We have generated a conditional deletion in mice of the von Hippel-Lindau factor (VHL) in myeloid cells to determine the effect of a deregulated hypoxic response in pulmonary oedema. RESULTS The deletion of VHL in pulmonary myeloid cells gave rise to pulmonary oedema, increased pulmonary vascular permeability and reduced performance during exertion. These changes were accompanied by reduced stroke volume in the left ventricle. CONCLUSION In this model, we show that a deregulated myeloid cell hypoxic response can trigger some of the most important symptoms of HAPE, and thus mice with a deletion of VHL in the myeloid lineage can function as a model of HAPE.
Collapse
Affiliation(s)
- Milos Gojkovic
- Department of Cell and Molecular Biology Karolinska Institute Stockholm Sweden
| | | | - Pedro Veliça
- Department of Cell and Molecular Biology Karolinska Institute Stockholm Sweden
| | - Helene Rundqvist
- Department of Physiology and Pharmacology Karolinska Institute Stockholm Sweden
| | - Randall S. Johnson
- Department of Cell and Molecular Biology Karolinska Institute Stockholm Sweden
- Department of Physiology Development and Neuroscience University of Cambridge Cambridge UK
| |
Collapse
|
48
|
Jha V, Jha A. Swine-influenza (H1N1 influenza) mimicking a case of high altitude pulmonary oedema (HAPO). BMJ Case Rep 2020; 13:13/6/e232564. [DOI: 10.1136/bcr-2019-232564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Here we present a case of a 37-year-old soldier of Indian Army, posted in high altitude area of Ladakh region (>4200 m), who after rejoining after a month leave, presented with dry cough, low-grade fever and dyspnoea on exertion while undergoing acclimatisation, and on examination, was detected to have hypoxaemia, fever and bilateral fine crepitations on chest auscultation. He was started on treatment for high altitude pulmonary oedema at a medical aid post, and later referred to General Hospital at Leh. The course of the illness was complicated by worsening hypoxaemia, continuous high-grade fever, leucopenia and hypotension. Focused medical history revealed that he had travelled to the state of Gujarat during his leave, where high incidence of H1N1 influenza was being reported during the ongoing pandemic. Oseltamivir was empirically started, in addition to parenteral antibiotics and he was started on inotropic support. In view of severe hypoxaemia, not responding to non-invasive ventilation, he was intubated and placed on mechanical ventilation. The patient turned out to be H1N1 positive and succumbed to his illness 3 days later.
Collapse
|
49
|
Evans AM, Hardie DG. AMPK and the Need to Breathe and Feed: What's the Matter with Oxygen? Int J Mol Sci 2020; 21:ijms21103518. [PMID: 32429235 PMCID: PMC7279029 DOI: 10.3390/ijms21103518] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/12/2022] Open
Abstract
We live and to do so we must breathe and eat, so are we a combination of what we eat and breathe? Here, we will consider this question, and the role in this respect of the AMP-activated protein kinase (AMPK). Emerging evidence suggests that AMPK facilitates central and peripheral reflexes that coordinate breathing and oxygen supply, and contributes to the central regulation of feeding and food choice. We propose, therefore, that oxygen supply to the body is aligned with not only the quantity we eat, but also nutrient-based diet selection, and that the cell-specific expression pattern of AMPK subunit isoforms is critical to appropriate system alignment in this respect. Currently available information on how oxygen supply may be aligned with feeding and food choice, or vice versa, through our motivation to breathe and select particular nutrients is sparse, fragmented and lacks any integrated understanding. By addressing this, we aim to provide the foundations for a clinical perspective that reveals untapped potential, by highlighting how aberrant cell-specific changes in the expression of AMPK subunit isoforms could give rise, in part, to known associations between metabolic disease, such as obesity and type 2 diabetes, sleep-disordered breathing, pulmonary hypertension and acute respiratory distress syndrome.
Collapse
Affiliation(s)
- A. Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, Edinburgh Medical School, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
- Correspondence:
| | - D. Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK;
| |
Collapse
|
50
|
Eichstaedt CA, Benjamin N, Grünig E. Genetics of pulmonary hypertension and high-altitude pulmonary edema. J Appl Physiol (1985) 2020; 128:1432-1438. [PMID: 32324476 DOI: 10.1152/japplphysiol.00113.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heritable pulmonary arterial hypertension (PAH) is an autosomal dominantly inherited disease caused by mutations in the bone morphogenetic protein receptor 2 (BMPR2) gene and/or genes of its signaling pathway in ~85% of patients. A genetic predisposition to high-altitude pulmonary edema (HAPE) has long been suspected because of familial HAPE cases, but very few possibly disease-causing mutations have been identified to date. This minireview provides an overview of genetic analyses investigating common polymorphisms in HAPE-susceptible patients and the directed identification of disease-causing mutations in PAH patients. Increased pulmonary artery pressure is highlighted as an overlapping clinical feature of the two diseases. Moreover, studies showing increased pulmonary artery pressures in HAPE-susceptible patients during exercise or hypoxia as well as in healthy BMPR2 mutation carriers are illustrated. Finally, high-altitude pulmonary hypertension is introduced and future research perspectives outlined.
Collapse
Affiliation(s)
- Christina A Eichstaedt
- Centre for Pulmonary Hypertension, Thoraxklinik Heidelberg gGmbH at Heidelberg University Hospital, Heidelberg Germany.,Laboratory for Molecular Genetic Diagnostics, Institute of Human Genetics, Heidelberg University, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Nicola Benjamin
- Centre for Pulmonary Hypertension, Thoraxklinik Heidelberg gGmbH at Heidelberg University Hospital, Heidelberg Germany.,Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| | - Ekkehard Grünig
- Centre for Pulmonary Hypertension, Thoraxklinik Heidelberg gGmbH at Heidelberg University Hospital, Heidelberg Germany.,Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg, Germany
| |
Collapse
|