Jiaojiao Yin, Yuhang Wang, Bing Li, Xiaoyan Hu, Yao Ma, Chong Zhang, Xiaoqin Ha, Linyan Wang, Yaozhu Pan
{"title":"Hypobaric Hypoxia Increased Autophagy and Apoptosis in PC12 Rat Pheochromocytoma Cells More Than Normobaric Hypoxia.","authors":"Jiaojiao Yin, Yuhang Wang, Bing Li, Xiaoyan Hu, Yao Ma, Chong Zhang, Xiaoqin Ha, Linyan Wang, Yaozhu Pan","doi":"10.1089/ham.2024.0041","DOIUrl":"https://doi.org/10.1089/ham.2024.0041","url":null,"abstract":"<p><p>Jiaojiao Yin, Yuhang Wang, Bing Li, Xiaoyan Hu, Yao Ma, Chong Zhang, Xiaoqin Ha, Linyan Wang, and Yaozhu Pan. Hypobaric hypoxia increased autophagy and apoptosis in PC12 rat pheochromocytoma cells more than normobaric hypoxia. <i>High Alt Med Biol.</i> 00:00-00, 2025. <b><i>Purpose:</i></b> Currently, <i>in vitro</i> studies have focused on hypoxia injury in acute mountain sickness (AMS), but little effort has been made to assess the effects of hypobaric hypoxia. AMS is a neurological disorder, and rat pheochromocytoma (PC12) cells are a model to study neuronal survival and apoptosis. Here, we developed a novel cell culture method that mimics hypobaric hypoxia at high attitude and compared the effects of hypobaric hypoxia and normobaric hypoxia on autophagy and apoptosis of PC12 cells. <b><i>Methods:</i></b> PC12 cells were cultured under normal conditions, normobaric hypoxia, and hypobaric hypoxia. Autophagy was observed by transmission electron microscopy and immunofluorescence microscopy. The hypoxia-inducible factor1-α (HIF1-α), LC3, caspase-3, and cleaved caspase-3 expression levels were determined by Western blot. <b><i>Results:</i></b> The cell culture chamber mimicking hypobaric hypoxia at high attitude perfectly maintained the air pressure at 41.1 kPa and the oxygen density at 1% (PO<sub>2</sub> around 3.08 mmHg). Hypobaric hypoxic treatment of PC12 cells at 0, 4, 8, 16, 24, and 48 hours resulted in an increase in HIF1-α and LC3Ⅱ protein levels, and the ratio of HIF1-α/actin and LC3Ⅱ/actin both peaked at 16 hours (<i>p</i> < 0. 01) when the cell viability was 88.02%. There was a 1.5-fold increase in LC3Ⅱ expression, a 2-fold increase in LC3B-positive spots, and an increase in autophagosome accumulation at hypobaric hypoxia compared to PC12 cells at normobaric hypoxia for 16 hours (<i>p</i> < 0.001). Interestingly, the promotion of autophagy (coculture with rapamycin or 3-MA) in PC12 cells under normobaric hypoxia reduced cleaved caspase-3 expression (the ratio of cleaved caspase-3/caspase-3 decreased, <i>p</i> < 0.01). However, under hypobaric hypoxia, the promotion of autophagy inversely increased cleaved caspase-3 (the ratio of cleaved caspase-3/caspase-3 increased, <i>p</i> < 0.01), and the inhibition of autophagy (hydroxychloroquine [HCQ] coculture) decreased cleaved caspase-3 (the ratio of cleaved caspase-3/caspase-3 decreased, <i>p</i> < 0.01). <b><i>Conclusions:</i></b> Compared with normobaric hypoxia cells, hypobaric hypoxia cells cultured <i>in vitro</i> exhibited increased autophagy and apoptosis.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143390609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Medical Problems of Chronic Hypoxia in Highlanders Living on the Tibetan Plateau.","authors":"Ri-Li Ge","doi":"10.1089/ham.2024.0107","DOIUrl":"https://doi.org/10.1089/ham.2024.0107","url":null,"abstract":"<p><p>Ri-Li Ge. Medical problems of chronic hypoxia in highlanders living on the tibetan plateau. <i>High Alt Med Biol.</i> 00:00-00, 2024.-Health issues at high altitudes arise due to the lower atmospheric pressure and subsequent reduction in the partial pressure of oxygen in ambient air. While much research has been published on health problems of lowlanders who move to high altitudes, less is known about the medical challenges faced by long-term and permanent high-altitude residents, especially in the Qinghai-Tibetan plateau. In this review, we briefly summarized the chronic hypoxia-related health issues in highlanders, focusing on the specific population of the Qinghai-Tibetan plateau. It deals with important health problems for highlanders, including the main disease categories, from chronic mountain sicknesses and pulmonary hypertension (PH) to kidney, neurocognitive impairments, perinatal problems, and congenital heart defect. However, the most hallmark of disorders is excessive erythrocytosis associated with specific symptoms and signs, and high-altitude heart disease is characterized by excessive PH, right ventricular hypertrophy, and right heart failure. We also provide information on potential treatment strategies, including some traditional Tibetan medical practices and also a combination of Western medicine and traditional Chinese medicine to prevent and treat these conditions effectively. This mini-review is heavily based on a couple of decades of research carried out by Chinese high-altitude medical research groups at the Qinghai-Tibetan Plateau. We believe that this review will provide valuable perspective to researchers whose study interest and base lie in high altitude.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143004506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
William Cornwell, Aaron L Baggish, Christoph Dehnert, Benjamin D Levine, Andrew M Luks
{"title":"Clinical Conundrum: Climbing at the Extremes of High Elevation with Nonischemic Cardiomyopathy.","authors":"William Cornwell, Aaron L Baggish, Christoph Dehnert, Benjamin D Levine, Andrew M Luks","doi":"10.1089/ham.2024.0143","DOIUrl":"https://doi.org/10.1089/ham.2024.0143","url":null,"abstract":"<p><p>Cornwell, William, Aaron L Baggish, Christoph Dehnert, Benjamin D Levine, and Andrew M Luks. Clinical Conundrum: Climbing at the Extremes of High Elevation with Nonischemic Cardiomyopathy. <i>High Alt Med Biol.</i> 00:00-00, 2024.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142947815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alina Häfliger, Aline Buergin, Laura C Mayer, Maamed Mademilov, Mona Lichtblau, Talantbek Sooronbaev, Silvia Ulrich, Konrad E Bloch, Michael Furian
{"title":"Sex-Specific Difference in Health-Related Altitude-Effects and Their Prevention by Acetazolamide. Data from a Randomized Controlled Trial.","authors":"Alina Häfliger, Aline Buergin, Laura C Mayer, Maamed Mademilov, Mona Lichtblau, Talantbek Sooronbaev, Silvia Ulrich, Konrad E Bloch, Michael Furian","doi":"10.1089/ham.2024.0011","DOIUrl":"https://doi.org/10.1089/ham.2024.0011","url":null,"abstract":"<p><p>Häfliger, Alina, Aline Buergin, Laura C. Mayer, Maamed Mademilov, Mona Lichtblau, Talantbek Sooronbaev, Silvia Ulrich, Konrad E. Bloch, and Michael Furian. Sex-specific difference in health-related altitude-effects and their prevention by acetazolamide. Data from a randomized controlled trial. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> Women are underrepresented in studies on acute mountain sickness (AMS), altitude-induced sleep-disordered breathing and preventive acetazolamide use. <b><i>Methods:</i></b> We analyzed sex-specific altitude-effects in participants of a randomized, placebo-controlled, double-blind trial in healthy lowlanders >40 years. Participants took 375 mg/day acetazolamide or placebo starting 24 hours before ascent to and while staying 2 days at 3,100 m. Main outcomes of this analysis were sex-specific incidence of AMS (Lake Louise score ≥3), nocturnal pulse oximetry (SpO<sub>2</sub>) and apnea-hypopnea index (AHI) at 3,100 m. <b><i>Results:</i></b> With placebo, 30 of 119 (25%) women and 4 of 51 (8%) men developed AMS (<i>p</i> = 0.009 between sexes) at 3,100 m. Among women assigned to placebo, SpO<sub>2</sub> (mean ± SE 84 ± 0%) and AHI (16.9 ± 1.3/h) in night 1 at 3,100 m were lower compared to men (SpO<sub>2</sub> 86 ± 0%; AHI 28.3 ± 1.9/h), despite similar baseline values at 760 m. Mean between-sex difference in altitude-effects (women-men) in SpO<sub>2</sub> was -1.4% (95% CI, -2.4 to -0.3%); AHI -10.7/h (95% CI, -15.7 to -5.7/h). The impact of acetazolamide on AMS was not significant for either sex but acetazolamide improved AHI in men (difference men-women, -9.8/h [95% CI, -16.8 to -2.7/h]). <b><i>Conclusion:</i></b> This study suggests sex-specific differences in altitude-induced hypoxemia, periodic breathing, AMS incidence, and in the response to preventive acetazolamide treatment.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142947818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unraveling High Altitude-Induced Thromboembolic Disorders: Polycythemia or Complex Mechanisms?","authors":"Nikunj Kumar Kansara, Anurag Timothy, Rijesh Unnithan, Manas Chatterjee","doi":"10.1089/ham.2023.0121","DOIUrl":"https://doi.org/10.1089/ham.2023.0121","url":null,"abstract":"<p><p>Kansara, Nikunj Kumar, Anurag Timothy, Rijesh Unnithan, and Manas Chatterjee. Unraveling high altitude-induced thromboembolic disorders: polycythemia or complex mechanisms?. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> Thromboembolic disorders (TEDs) occurring at high altitudes due to exposure to hypoxic environments pose a significant challenge for clinicians in high-altitude area. Hypobaric hypoxia often leads to acquired erythrocytosis, which is believed to increase the incidence of thrombosis. This study aims to examine the relationship between thromboembolic events and erythrocytosis. <b><i>Methodology:</i></b> A prospective study was conducted, including all the patients admitted to Siachen hospital for TEDs from January 01, 2022, to December 31, 2022. Data on height, duration of the stay, hemoglobin (Hb), and packed cell volume levels at the time of admission were recorded. <b><i>Results:</i></b> A total of 35 cases were enrolled during the study period. The average age of the patients was 29.10 years (standard deviation: 6.06). The mean deployment height was 17,300 ft, with a range of 12,000 ft-21,600 ft. The average duration of stay was 73 days, ranging from 7 to 162 days. The mean Hb level was 18 g/dl (SD: 2.64), with a range of 12.4 g/dl-22.4 g/dl. Twenty-five cases of thrombotic events (71.4%) occurred with normal Hb levels (<17.5 mg/dl), compared with 10 cases (28.6%) with Hb levels >17.5 mg/dl. <b><i>Conclusion:</i></b> Prolonged stays at high altitudes and exposure to hypobaric hypoxia are major stressors. The study suggests that it is not elevated Hb levels, but rather the body's lack of an appropriate physiological response, that contributes to the development of thromboembolic events.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142931598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emeric Stauffer, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, Benoit Champigneulle
{"title":"Acclimatized Lowlanders Exhibit a Hypocoagulable Profile after a Passive Ascent at High Altitude.","authors":"Emeric Stauffer, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, Benoit Champigneulle","doi":"10.1089/ham.2024.0128","DOIUrl":"https://doi.org/10.1089/ham.2024.0128","url":null,"abstract":"<p><p>Stauffer, Emeric, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, and Benoit Champigneulle.Acclimatized lowlanders exhibit a hypocoagulable profile after a passive ascent at high altitude. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> Discordant results have been previously reported regarding the impact of high-altitude (HA) exposure on coagulation. We aimed to investigate changes in coagulation parameters in lowlanders exposed to HA for 14 days using a combination of dynamic coagulation assays and conventional <i>in vitro</i> tests. <b><i>Material and Methods:</i></b> We assessed coagulation in 10 lowlanders using whole-blood rotational thromboelastometry (ROTEM), thrombin generation assay (TGA) on poor-platelet plasma, and conventional coagulation tests. Tests were performed at low altitude (LA, 210 m) and at the end of a 14-day sojourn at HA, including passive ascents to 3,800 m for 6 days and then to 5,100 m for 8 days. <b><i>Results:</i></b> Conventional tests revealed significant changes in coagulation factors and inhibitors after HA exposure, although these changes remained within normal ranges. ROTEM assays demonstrated a delayed clot initiation in EXTEM/FIBTEM, without any alteration in clot firmness, in HA versus LA (<i>p</i> < 0.01). TGA changes showed an increase in time to peak (<i>p</i> < 0.01), a decrease in endogenous thrombin potential (<i>p</i> < 0.05), and a decrease in thrombin peak (<i>p</i> < 0.001). <b><i>Conclusions:</i></b> We found no evidence of hypercoagulability in lowlanders after a 14-day sojourn at HA. In contrast, dynamic coagulation assays (ROTEM and TGA) revealed a hypocoagulable pattern.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142846516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temporal Effects of Hypoxia Exposure at High Altitudes on Compensatory Brain Function: Evidence from Functional Connectivity of Resting-State EEG Brain Networks.","authors":"Hong Ren, Xi-Yue Yang, Rui Su, HaiLin Ma, Hao Li","doi":"10.1089/ham.2024.0063","DOIUrl":"https://doi.org/10.1089/ham.2024.0063","url":null,"abstract":"<p><p>Ren, Hong, Xi-Yue Yang, Rui Su, HaiLin Ma, and Hao Li. Temporal Effects of Hypoxia Exposure at High Altitudes on Compensatory Brain Function: Evidence from Functional Connectivity of Resting-State EEG Brain Networks. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> The aim of this study was to investigate the effects of prolonged exposure to hypobaric hypoxia at high altitude on changes in brain function measured by electroencephalography (EEG), focusing specifically on the resting-state brain network functional connectivity and compensatory adaptations in brain function among individuals with varying durations of high altitude residency. <b><i>Methods:</i></b> In study I, 64 participants were divided into high-altitude group (HG) and low-altitude group (LG). Ninety-six long-term migrants residing at an altitude of 3,650 m were recruited for studyII and categorized into three groups based on their duration of stay at high altitude: group A (1-2 years), group B (8-10 years), and group C (18-20 years). Resting-state EEG data were collected from each participant, and functional connectivity analysis was conducted using Phase Locking Value. <b><i>Results:</i></b> Study I showed that participants with HG had stronger functional connectivity in the occipital lobe than those with LG (<i>p</i> < 0.05). The study II findings indicate that there were significant differences in functional connectivity strength among the frontal and occipital lobes in groups A, B, and C across the α, β, δ, and θ frequency bands. Specifically, the functional connectivity strength of the frontal lobe was significantly higher in group A compared with group B, and in group B compared with group C (<i>p</i> < 0.05). Additionally, the functional connectivity of the occipital lobe was significantly higher in group C compared with group B, and in group B compared with group A (<i>p</i> < 0.05). <b><i>Conclusions:</i></b> The consistent results of the whole frequency band suggest that the individual's occipital lobe function is enhanced to compensate for the damage of frontal lobe function, so as to better adapt to the extreme environment at high altitude.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142846529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elizabeth V Young, Matea A Djokic, Erica C Heinrich, Traci Marin, Cecilia Anza-Ramirez, Jeremy E Orr, Dillon Gilbertson, Pamela N DeYoung, Gustavo Vizcardo-Galindo, Rómulo Figueroa-Mujica, Francisco C Villafuerte, Atul Malhotra, Tatum S Simonson
{"title":"The Effects of Nocturnal Hypoxemia on Cognitive Performance in Andean Highlanders.","authors":"Elizabeth V Young, Matea A Djokic, Erica C Heinrich, Traci Marin, Cecilia Anza-Ramirez, Jeremy E Orr, Dillon Gilbertson, Pamela N DeYoung, Gustavo Vizcardo-Galindo, Rómulo Figueroa-Mujica, Francisco C Villafuerte, Atul Malhotra, Tatum S Simonson","doi":"10.1089/ham.2024.0077","DOIUrl":"10.1089/ham.2024.0077","url":null,"abstract":"<p><p><b><i>Background:</i></b> Many Andean highlanders exposed to chronic hypoxemia are susceptible to excessive erythrocytosis (EE) and chronic mountain sickness (CMS). Nocturnal hypoxemia is more marked than diurnal hypoxemia and includes sustained and intermittent components. The potential for cognitive impairments related to nocturnal hypoxemia in this population has not been extensively studied, but improved understanding may provide opportunities for the prevention of long-term effects of EE and CMS. <b><i>Methods:</i></b> To examine this relationship, 48 participants residing permanently at 4,340 m completed an overnight sleep study and a battery of cognitive function tests that examined a broad range of cognitive domains. <b><i>Results:</i></b> Greater nocturnal hypoxemia was associated with longer reaction times on Balloon Analogue Risk Task (BART) (<i>p</i> < 0.01) and Emotion Recognition Test (ERT) (<i>p</i> < 0.01). Longer completion times of Trail Making Task were also associated with increased nocturnal hypoxemia (<i>p</i> = 0.03). Increased hematocrit was similarly associated with longer reaction times on the ERT (<i>p</i> = 0.01) and the BART (<i>p</i> = 0.01). <b><i>Conclusion:</i></b> Overall, our results showed that increased nocturnal hypoxemia and higher hematocrit were associated with impairments in cognitive performance in individuals residing permanently at high altitude.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142806879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yan Guo, Chao Yu, Zhongsheng Lu, Menglan Zhang, Qiang Zhang, Xiao Liu
{"title":"Zinc Homeostasis Plays Important Roles in Hypoxia Tolerance: A Study Conducted Clinically and <i>In Vitro</i>.","authors":"Yan Guo, Chao Yu, Zhongsheng Lu, Menglan Zhang, Qiang Zhang, Xiao Liu","doi":"10.1089/ham.2024.0036","DOIUrl":"https://doi.org/10.1089/ham.2024.0036","url":null,"abstract":"<p><p>Guo, Yan, Chao Yu, Zhongsheng Lu, Menglan Zhang, Qiang Zhang, and Xiao Liu. Zinc homeostasis plays important roles in hypoxia tolerance: A study conducted clinically and <i>in vitro</i>. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Objective:</i></b> High-altitude environments pose significant challenges to human physiology due to reduced oxygen availability, often resulting in altitude-related illnesses such as high-altitude cerebral edema (HACE). This study focuses on understanding the role of zinc homeostasis in enhancing hypoxia tolerance, which may be pivotal in mitigating the adverse effects of such illnesses. <b><i>Methods:</i></b> The study involved healthy individuals from high-altitude (4,500-5,000 m) and low-altitude areas (0-200 m), as well as patients with HACE. Blood samples were collected and analyzed. Additionally, a hypoxic model was developed using human brain microvascular endothelial cells (HBMECs), and zinc intervention was implemented. <b><i>Results:</i></b> In the blood samples of patients with HACE and those of healthy individuals, there were over 4,000 differentially expressed genes (DEGs), with more than 300 of them linked to zinc. Among these zinc-associated genes, only carbonic anhydrase I (CA1) exhibited a substantial upregulation in expression, while the expression of others was notably downregulated. Compared with the high-altitude group, hemoglobin (Hb) (14.7 vs. 19.5 g/dl) and plasma zinc (37.0 vs. 94.0 mmol/dl) were lower in HACE, while CA1 (55.4 vs. 8.6 g/l) was elevated (<i>p</i> < 0.01). <i>In vitro</i> studies confirmed that exposure to hypoxia (O<sub>2</sub> 8%-8.5%, 24 hours) inhibited HBMECs proliferation and migration, increased apoptosis and necrosis, and led to abnormal expression of CA1 and various zinc transport proteins. However, zinc intervention (6 μM, 24 hours) significantly mitigated these adverse effects and improved the cell's ability to tolerate hypoxia. <b><i>Conclusion:</i></b> Zinc homeostasis was crucial for hypoxia tolerance. Proper zinc supplementation could potentially alleviate symptoms associated with hypoxia intolerance, such as altitude sickness, but further confirmation was needed.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142806881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"<i>Letter to the Editor:</i> Vital Signs Below 24°C. A Positive Contribution of Alcohol to Survival in Hypothermia?","authors":"Ian J Cohen","doi":"10.1089/ham.2024.0136","DOIUrl":"https://doi.org/10.1089/ham.2024.0136","url":null,"abstract":"","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142780194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}