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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.
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Winter C, Bjorkman T, Miller S, Nichols P, Cardinal J, O'Rourke P, Ballard E, Nasrallah F, Vegh V. Acute Mountain Sickness Following Incremental Trekking to High Altitude: Correlation With Plasma Vascular Endothelial Growth Factor Levels and the Possible Effects of Dexamethasone and Acclimatization Following Re-exposure. Front Physiol 2021; 12:746044. [PMID: 34744786 PMCID: PMC8567072 DOI: 10.3389/fphys.2021.746044] [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: 07/23/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: The recognition and treatment of high-altitude illness (HAI) is increasingly important in global emergency medicine. High altitude related hypobaric hypoxia can lead to acute mountain sickness (AMS), which may relate to increased expression of vascular endothelial growth factor (VEGF), and subsequent blood-brain barrier (BBB) compromise. This study aimed to establish the relationship between AMS and changes in plasma VEGF levels during a high-altitude ascent. VEGF level changes with dexamethasone, a commonly used AMS medication, may provide additional insight into AMS. Methods: Twelve healthy volunteers ascended Mt Fuji (3,700 m) and blood samples were obtained at distinct altitudes for VEGF analysis. Oxygen saturation (SPO2) measurements were also documented at the same time-point. Six out of the 12 study participants were prescribed dexamethasone for a second ascent performed 48 h later, and blood was again collected to establish VEGF levels. Results: Four key VEGF observations could be made based on the data collected: (i) the baseline VEGF levels between the two ascents trended upwards; (ii) those deemed to have AMS in the first ascent had increased VEGF levels (23.8–30.3 pg/ml), which decreased otherwise (23.8–30.3 pg/ml); (iii) first ascent AMS participants had higher VEGF level variability for the second ascent, and similar to those not treated with dexamethasone; and (iv) for the second ascent dexamethasone participants had similar VEGF levels to non-AMS first ascent participants, and the variability was lower than for first ascent AMS and non-dexamethasone participants. SPO2 changes were unremarkable, other than reducing by around 5% irrespective of whether measurement was taken for the first or second ascent. Conclusion: First ascent findings suggest a hallmark of AMS could be elevated VEGF levels. The lack of an exercise-induced VEGF level change strengthened the notion that elevated plasma VEGF was brain-derived, and related to AMS.
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Affiliation(s)
- Craig Winter
- Kenneth Jamieson Department of Neurosurgery, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.,UQ Center for Clinical Research, University of Queensland, Brisbane, QLD, Australia.,School of Mechanical, Medical and Process Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Tracy Bjorkman
- UQ Center for Clinical Research, University of Queensland, Brisbane, QLD, Australia
| | - Stephanie Miller
- UQ Center for Clinical Research, University of Queensland, Brisbane, QLD, Australia
| | - Paul Nichols
- Kenneth Jamieson Department of Neurosurgery, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.,UQ Center for Clinical Research, University of Queensland, Brisbane, QLD, Australia
| | - John Cardinal
- School of Human Movement Studies, University of Queensland, Brisbane, QLD, Australia
| | - Peter O'Rourke
- Queensland Institute of Medical Research, Brisbane, QLD, Australia
| | - Emma Ballard
- Queensland Institute of Medical Research, Brisbane, QLD, Australia
| | - Fatima Nasrallah
- Queensland Brain Institute, University of Queensland, Brisbane, QLD, Australia
| | - Viktor Vegh
- Centre for Advanced Imaging, University of Queensland, Brisbane, QLD, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, Brisbane, QLD, Australia
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3
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Tenzing N, van Patot MT, Liu H, Xu Q, Liu J, Wang Z, Wang Y, Wuren T, Ge RL. Identification of a miRNA-mRNA Regulatory Networks in Placental Tissue Associated With Tibetan High Altitude Adaptation. Front Genet 2021; 12:671119. [PMID: 34567059 PMCID: PMC8460760 DOI: 10.3389/fgene.2021.671119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 07/30/2021] [Indexed: 11/15/2022] Open
Abstract
The Tibetan population has lived and successfully reproduced at high altitude for many generations. Studies have shown that Tibetans have various mechanisms for protection against high-altitude hypoxia, which are probably due, at least in part, to placental adaptation. However, comprehensive in silico analyses of placentas in Tibetans are lacking. We performed a microarray-based comparative transcriptome analysis of 10 Tibetan women from Yushu, Qinghai, CHN (∼3,780 m) and 10 European women living in Leadville, CO, United States (∼3,100 m) for less than three generations. Expression of HIF-1α, STAT3, EGFR, HSP5A, XBP1, and ATF6A mRNA was less in the Tibetan placentas as compared with European placentas. A total of 38 miRNAs were involved in regulating these genes. Differentially expressed genes were enriched for HIF1α signaling pathways, protein processing in the endoplasmic reticulum, PI3K-AKT signaling pathways, and MAPK signaling pathways. Based on the transcriptome profiles, the Tibetan population was distinct from the European population; placental tissues from the Tibetan population are lacking hypoxic responses, and “passivation” occurs in response to hypoxic stress. These results provide insights into the molecular signature of adaptation to high altitudes in these two populations.
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Affiliation(s)
- Noryung Tenzing
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | | | - Huifang Liu
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | - Qiying Xu
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | - Juanli Liu
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Qinghai Provincial People's Hospital, Xining, China
| | - Zhuoya Wang
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | - Yanjun Wang
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | - Tana Wuren
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China
| | - Ri-Li Ge
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China
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4
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Lemieux P, Birot O. Altitude, Exercise, and Skeletal Muscle Angio-Adaptive Responses to Hypoxia: A Complex Story. Front Physiol 2021; 12:735557. [PMID: 34552509 PMCID: PMC8450406 DOI: 10.3389/fphys.2021.735557] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/16/2021] [Indexed: 12/18/2022] Open
Abstract
Hypoxia, defined as a reduced oxygen availability, can be observed in many tissues in response to various physiological and pathological conditions. As a hallmark of the altitude environment, ambient hypoxia results from a drop in the oxygen pressure in the atmosphere with elevation. A hypoxic stress can also occur at the cellular level when the oxygen supply through the local microcirculation cannot match the cells’ metabolic needs. This has been suggested in contracting skeletal myofibers during physical exercise. Regardless of its origin, ambient or exercise-induced, muscle hypoxia triggers complex angio-adaptive responses in the skeletal muscle tissue. These can result in the expression of a plethora of angio-adaptive molecules, ultimately leading to the growth, stabilization, or regression of muscle capillaries. This remarkable plasticity of the capillary network is referred to as angio-adaptation. It can alter the capillary-to-myofiber interface, which represent an important determinant of skeletal muscle function. These angio-adaptive molecules can also be released in the circulation as myokines to act on distant tissues. This review addresses the respective and combined potency of ambient hypoxia and exercise to generate a cellular hypoxic stress in skeletal muscle. The major skeletal muscle angio-adaptive responses to hypoxia so far described in this context will be discussed, including existing controversies in the field. Finally, this review will highlight the molecular complexity of the skeletal muscle angio-adaptive response to hypoxia and identify current gaps of knowledges in this field of exercise and environmental physiology.
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Affiliation(s)
- Pierre Lemieux
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Olivier Birot
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, ON, Canada
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5
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Bhandari S, Cavalleri GL. Population History and Altitude-Related Adaptation in the Sherpa. Front Physiol 2019; 10:1116. [PMID: 31555147 PMCID: PMC6722185 DOI: 10.3389/fphys.2019.01116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 08/12/2019] [Indexed: 12/29/2022] Open
Abstract
The first ascent of Mount Everest by Tenzing Norgay and Sir Edmund Hillary in 1953 brought global attention to the Sherpa people and human performance at altitude. The Sherpa inhabit the Khumbu Valley of Nepal, and are descendants of a population that has resided continuously on the Tibetan plateau for the past ∼25,000 to 40,000 years. The long exposure of the Sherpa to an inhospitable environment has driven genetic selection and produced distinct adaptive phenotypes. This review summarizes the population history of the Sherpa and their physiological and genetic adaptation to hypoxia. Genomic studies have identified robust signals of positive selection across EPAS1, EGLN1, and PPARA, that are associated with hemoglobin levels, which likely protect the Sherpa from altitude sickness. However, the biological underpinnings of other adaptive phenotypes such as birth weight and the increased reproductive success of Sherpa women are unknown. Further studies are required to identify additional signatures of selection and refine existing Sherpa-specific adaptive phenotypes to understand how genetic factors have underpinned adaptation in this population. By correlating known and emerging signals of genetic selection with adaptive phenotypes, we can further reveal hypoxia-related biological mechanisms of adaptation. Ultimately this work could provide valuable information regarding treatments of hypoxia-related illnesses including stroke, heart failure, lung disease and cancer.
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Affiliation(s)
- Sushil Bhandari
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gianpiero L Cavalleri
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
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6
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Gilbert-Kawai ET, Milledge JS, Grocott MP, Martin DS. King of the Mountains: Tibetan and Sherpa Physiological Adaptations for Life at High Altitude. Physiology (Bethesda) 2014; 29:388-402. [DOI: 10.1152/physiol.00018.2014] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Anecdotal evidence surrounding Tibetans' and Sherpas' exceptional tolerance to hypobaric hypoxia has been recorded since the beginning of high-altitude exploration. These populations have successfully lived and reproduced at high altitude for hundreds of generations with hypoxia as a constant evolutionary pressure. Consequently, they are likely to have undergone natural selection toward a genotype (and phenotype) tending to offer beneficial adaptation to sustained hypoxia. With the advent of translational human hypoxic research, in which genotype/phenotype studies of healthy individuals at high altitude may be of benefit to hypoxemic critically ill patients in a hospital setting, high-altitude natives may provide a valuable and intriguing model. The aim of this review is to provide a comprehensive summary of the scientific literature encompassing Tibetan and Sherpa physiological adaptations to a high-altitude residence. The review demonstrates the extent to which evolutionary pressure has refined the physiology of this high-altitude population. Furthermore, although many physiological differences between highlanders and lowlanders have been found, it also suggests many more potential avenues of investigation.
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Affiliation(s)
- Edward T. Gilbert-Kawai
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
- University College London Division of Surgery and Interventional Science, Royal Free Hospital, London, United Kingdom
- University College Hospital London NIHR Biomedical Research Centre, London, United Kingdom
| | - James S. Milledge
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
| | - Michael P.W. Grocott
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
- University College Hospital London NIHR Biomedical Research Centre, London, United Kingdom
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, University of Southampton, Southampton, United Kingdom
- Anaesthesia and Critical Care Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom; and
- Southampton NIHR Respiratory Biomedical Research Unit, Southampton, United Kingdom
| | - Daniel S. Martin
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, United Kingdom
- University College London Division of Surgery and Interventional Science, Royal Free Hospital, London, United Kingdom
- University College Hospital London NIHR Biomedical Research Centre, London, United Kingdom
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7
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Buroker NE. Regulatory SNPs and transcriptional factor binding sites in ADRBK1, AKT3, ATF3, DIO2, TBXA2R and VEGFA. Transcription 2014; 5:e964559. [PMID: 25483406 PMCID: PMC4581348 DOI: 10.4161/21541264.2014.964559] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Abstract Regulatory single nucleotide polymorphisms (rSNPs) which change the transcriptional factor binding sites (TFBS) for transcriptional factors (TFs) to bind DNA were reviewed for the ADRBK1 (GRK2), AKT3, ATF3, DIO2, TBXA2R and VEGFA genes. Changes in the TFBS where TFs attach to regulate these genes may result in human sickness and disease. The highlights of this previous work were reviewed for these genes.
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Affiliation(s)
- Norman E Buroker
- Department of Pediatrics, University of Washington, Seattle, WA USA
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8
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Morici G, Bonanno A, Licciardi A, Valli G, Passino C, Bonardi D, Locorotondo N, Profita M, Palange P, Cogo A, Bonsignore MR. Plasma leptin and vascular endothelial growth factor (VEGF) in normal subjects at high altitude (5050 m). Arch Physiol Biochem 2013; 119:219-24. [PMID: 23862573 DOI: 10.3109/13813455.2013.814679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
CONTEXT High altitude (HA) is a model of severe hypoxia exposure in humans. We hypothesized that nocturnal hypoxemia or acute maximal exercise at HA might affect plasma leptin and VEGF levels. OBJECTIVES Plasma leptin, VEGF and other metabolic variables were studied after nocturnal pulse oximetry and after maximal exercise in healthy lowlanders on the 3rd-4th day of stay in Lobuche (5050 m, HA) and after return to sea level (SL). RESULTS Leptin was similar at SL or HA in both pre- and post-exercise conditions. Pre-exercise VEGF at HA was lower, and cortisol was higher, than at SL, suggesting that nocturnal intermittent hypoxia associated with periodic breathing at HA might affect these variables. CONCLUSIONS Leptin levels appear unaffected at HA, whereas nocturnal hypoxic stress may affect plasma VEGF. Future HA studies should investigate the possible role of nocturnal intermittent hypoxemia on metabolism.
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Affiliation(s)
- G Morici
- Department of Experimental Biomedicine and Clinical Neuroscience (BIONeC), University of Palermo , Italy
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9
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Affiliation(s)
- M. Nikinmaa
- Department of Biology; University of Turku; Turku; Finland
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10
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Buroker NE, Ning XH, Zhou ZN, Li K, Cen WJ, Wu XF, Zhu WZ, Scott CR, Chen SH. VEGFA SNPs and transcriptional factor binding sites associated with high altitude sickness in Han and Tibetan Chinese at the Qinghai-Tibetan Plateau. J Physiol Sci 2013; 63:183-93. [PMID: 23553563 PMCID: PMC10717492 DOI: 10.1007/s12576-013-0257-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 02/28/2013] [Indexed: 01/08/2023]
Abstract
Mountain sickness (MS) occurs among humans visiting or inhabiting high altitude environments. We conducted genetic analyses of seven single nucleotide polymorphisms (SNPs) in the promoter region of VEGFA gene for lowland (Han) and highland (Tibetan) Chinese. The seven SNPs were evaluated in Han and Tibetan patients with acute (A) and chronic (C) MS. We compared 64 patients with AMS with 64 Han unaffected with MS, as well as 48 CMS patients with 32 unaffected Tibetans. The SNPs studied are rs699947, rs34357231, rs79469752, rs13207351, rs28357093, rs1570360, and rs2010963 which are found in the promoter ranging from -2,578 to -634 bp from the transcriptional start site (TSS), respectively. Direct sequencing was used to identify individual genotypes for these SNPs. Arterial oxygen saturation of hemoglobin (SaO2) was found to be significantly associated with the rs699947, rs34357231, rs13207351, and rs1570360 SNPs in Han patients with AMS, while the rs2010963 SNP was found to approach significance in the AMS study group, but found to be significantly associated in the normal Tibetan study group. The Han and Tibetan control groups were found to diverge significantly for the rs28357093 and rs2010963 SNPs, as measured by genetic distances of 0.073 and 0.054, respectively. All the SNPs are found in transcriptional factor binding sites (TFBS), and their possible role in gene regulation was evaluated with regard to MS. MS was found to be significantly associated with these SNPs compared with their Han and Tibetan control groups, indicating that these nucleotide substitutions result in TFBS changes which apparently have a physiological effect on the development of high altitude sickness.
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Affiliation(s)
- Norman E Buroker
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA.
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11
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Cao Y. Erythropoietin in cancer: a dilemma in risk therapy. Trends Endocrinol Metab 2013; 24:190-9. [PMID: 23218687 DOI: 10.1016/j.tem.2012.10.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 10/19/2012] [Accepted: 10/25/2012] [Indexed: 12/19/2022]
Abstract
Erythropoietin (EPO) is a frequently prescribed drug for treatment of cancer-related and chemotherapy-induced anemia in cancer patients. Paradoxically, recent preclinical and clinical studies indicate that EPO could potentially accelerate tumor growth and jeopardize survival in cancer patients. In this review I critically discuss the current knowledge and broad biological functions of EPO in association with tumor growth, invasion, and angiogenesis. The emphasis is focused on discussing the complex interplay between EPO and other tumor-derived factors in angiogenesis, tumor growth, invasion, and metastasis. Understanding the multifarious functions of EPO and its reciprocal relation with other signaling pathways is crucial for developing more effective agents for cancer therapy and for minimizing risks for cancer patients.
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Affiliation(s)
- Yihai Cao
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, 171 77 Stockholm, Sweden.
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12
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Buroker NE, Ning XH, Zhou ZN, Li K, Cen WJ, Wu XF, Zhu WZ, Scott CR, Chen SH. AKT3, ANGPTL4, eNOS3, and VEGFA associations with high altitude sickness in Han and Tibetan Chinese at the Qinghai-Tibetan Plateau. Int J Hematol 2012; 96:200-13. [PMID: 22729570 DOI: 10.1007/s12185-012-1117-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 05/22/2012] [Accepted: 05/23/2012] [Indexed: 11/29/2022]
Abstract
Mountain sickness (MS) occurs among humans visiting or inhabiting high altitude environments. We conducted genetic analyses of the AKT3, ANGPTL4, eNOS3 and VEGFA genes in lowland (Han) and highland (Tibetan) Chinese. Ten single nucleotide polymorphisms (SNPs) were evaluated in Han and Tibetan patients with acute (A) and chronic (C) MS. We compared 74 patients with AMS to 79 Han unaffected with MS, as well as 48 CMS patients to 31 unaffected Tibetans. The ten SNPs studied are AKT3 (rs4590656, rs2291409), ANGPTL4 (rs1044250), eNOS3 (rs1007311, rs1799983) and VEGFA (rs79469752, rs13207351, rs28357093, rs1570360, rs3025039). Direct sequencing was used to identify individual genotypes for these SNPs. Hemoglobin (Hb), hematocrit (Hct), and red blood cell count (RBC) were found to be significantly associated with the AKT3 SNP (rs4590656), Hb was found to be associated with the eNOS3 SNP (rs1007311), and RBC was found to be significantly associated with the VEGFA SNP (rs1570360) in Tibetan patients with CMS. CMS patients were found to diverge significantly for both eNOS3 SNPs as measured by genetic distance (0.042, 0.047) and for the VEGFA SNP (rs28357093) with a genetic distance of 0.078 compared to their Tibetan control group. Heart rate (HR) was found to be significantly associated with the eNOS3 SNP (rs1799983) and arterial oxygen saturation of hemoglobin (SaO2) was found to be significantly associated with the VEGFA SNPs (rs13207351, rs1570360) in Han patients with AMS. The Han and Tibetan control groups were found to diverge significantly for the ANGPTL4 SNP and VEGFA SNP (rs28357093), as measured by genetic distances of 0.049 and 0.073, respectively. Seven of the SNPs from non-coding regions are found in the transcriptional factor response elements and their possible role in gene regulation was evaluated with regard to MS. AMS and CMS were found to be significantly associated with the four genes compared to their Han and Tibetan control groups, respectively, indicating that these nucleotide alterations have a physiological effect for the development of high altitude sickness.
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Affiliation(s)
- Norman E Buroker
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA.
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13
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Wahl P, Zinner C, Achtzehn S, Behringer M, Bloch W, Mester J. Effects of acid–base balance and high or low intensity exercise on VEGF and bFGF. Eur J Appl Physiol 2010; 111:1405-13. [DOI: 10.1007/s00421-010-1767-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2010] [Indexed: 10/18/2022]
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14
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Blei F. Literature Watch. Lymphat Res Biol 2010. [DOI: 10.1089/lrb.2010.8402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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15
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Bourguignon M, Yaghi L, Flajollet S, Radanne-Krawice I, Rouas-Freiss N, Lugrin D, Richalet JP, Carosella ED, Moreau P. Increased soluble human leukocyte antigen-G levels in peripheral blood from climbers on Mount Everest. Hum Immunol 2010; 71:1105-8. [PMID: 20732367 DOI: 10.1016/j.humimm.2010.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 07/23/2010] [Accepted: 08/16/2010] [Indexed: 01/12/2023]
Abstract
Soluble human leukocyte antigen-G (HLA-G) is involved in maternal-fetal tolerance, transplant acceptance, and tumor escape from immunosurveillance, operating by inhibiting activity of T, antigen presenting cells (APC), and natural killer (NK) cells. HLA-G gene expression is modulated in vitro after hypoxic conditions, a situation evidenced during pregnancy and tumor progression. In extreme altitude, mountaineers are in hypoxic conditions that generate physiologic adaptative responses, some of them giving rise to pathologic signs. We performed measurements of plasma soluble HLA-G in six climbers before departure of the expedition and during their ascent to and descent from summit of Mount Everest, and in 3 Sherpas at 5300-6400 m. We found that HLA-G levels are upregulated during the ascent with a unique pattern in comparison with angiogenic/lymphangiogenic factors. Our data suggest that HLA-G has to be taken into account in the mechanisms participating in adaptation to high altitudes and reinforce hypoxia as an important factor in the regulation of HLA-G expression.
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Affiliation(s)
- Michel Bourguignon
- Autorité de Sûreté Nucléaire, 6 place du colonel Bourgoin, Paris Cedex, France
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Abstract
NF-κB activation is a critical component in the transcriptional response to hypoxia. However, the underlying mechanisms that control its activity under these conditions are unknown. Here we report that under hypoxic conditions, IκB kinase (IKK) activity is induced through a calcium/calmodulin-dependent kinase 2 (CaMK2)-dependent pathway distinct from that for other common inducers of NF-κB. This process still requires IKK and the IKK kinase TAK1, like that for inflammatory inducers of NF-κB, but the TAK1-associated proteins TAB1 and TAB2 are not essential. IKK complex activation following hypoxia requires Ubc13 but not the recently identified LUBAC (linear ubiquitin chain assembly complex) ubiquitin conjugation system. In contrast to the action of other NF-κB inducers, IKK-mediated phosphorylation of IκBα does not result in its degradation. We show that this results from IκBα sumoylation by Sumo-2/3 on critical lysine residues, normally required for K-48-linked polyubiquitination. Furthermore, inhibition of specific Sumo proteases is sufficient to release RelA from IκBα and activate NF-κB target genes. These results define a novel pathway regulating NF-κB activation, important to its physiological role in human health and disease.
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Abstract
The ascent of humans to the summits of the highest peaks on Earth initiated a spurt of explorations into the physiological consequences of physical activity at altitude. The past three decades have demonstrated that the resetting of respiratory and cardiovascular control with chronic exposure to altitudes above 4000 m is accompanied by important structural-functional adjustments of skeletal muscle. The fully altitude-adapted phenotype preserves energy charge at reduced aerobic capacity through the promotion of anaerobic substrate flux and tighter metabolic control, often at the expense of muscle mass. In seeming contrast, intense physical activity at moderate hypoxia (2500 to 4000 m) modifies this response in both low and high altitude natives through metabolic compensation by elevating local aerobic capacity and possibly preventing muscle fiber atrophy. The combined use of classical morphometry and contemporary proteomic technology provides a highly resolved picture of the temporal control of hypoxia-induced muscular adaptations. The muscle proteome signature identifies mitochondrial autophagy and protein degradation as prime adaptive mechanisms to passive altitude exposure and ascent to extreme altitude. Protein measures also explain the lactate paradox by a sparing of glycolytic enzymes from general muscle wasting. Enhanced mitochondrial and angiogenic protein expression in human muscle with exercise up to 4000 m is related to the reduction in intramuscular oxygen content below 1% (8 torr), when the master regulator of hypoxia-dependent gene expression, HIF-1alpha, is stabilized. Accordingly, it is proposed here that the catabolic consequences of chronic hypoxia exposure reflect the insufficient activation of hypoxia-sensitive signaling and the suppression of energy-consuming protein translation.
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Affiliation(s)
- Martin Flueck
- Institute for Biomedical Research into Human Movement and Health, Manchester Metropolitan University, Manchester, UK.
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Fandrey J. The higher they climb: plasma levels of angiogenic and lymphangiogenic factors during ascent to Mount Everest. Acta Physiol (Oxf) 2009. [DOI: 10.1111/j.1748-1716.2009.01988_1.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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