1
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Keppler F, Boros M, Polag D. Radical-Driven Methane Formation in Humans Evidenced by Exogenous Isotope-Labeled DMSO and Methionine. Antioxidants (Basel) 2023; 12:1381. [PMID: 37507920 PMCID: PMC10376501 DOI: 10.3390/antiox12071381] [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: 05/26/2023] [Revised: 06/29/2023] [Accepted: 07/01/2023] [Indexed: 07/30/2023] Open
Abstract
Methane (CH4), which is produced endogenously in animals and plants, was recently suggested to play a role in cellular physiology, potentially influencing the signaling pathways and regulatory mechanisms involved in nitrosative and oxidative stress responses. In addition, it was proposed that the supplementation of CH4 to organisms may be beneficial for the treatment of several diseases, including ischemia, reperfusion injury, and inflammation. However, it is still unclear whether and how CH4 is produced in mammalian cells without the help of microorganisms, and how CH4 might be involved in physiological processes in humans. In this study, we produced the first evidence of the principle that CH4 is formed non-microbially in the human body by applying isotopically labeled methylated sulfur compounds, such as dimethyl sulfoxide (DMSO) and methionine, as carbon precursors to confirm cellular CH4 formation. A volunteer applied isotopically labeled (2H and 13C) DMSO on the skin, orally, and to blood samples. The monitoring of stable isotope values of CH4 convincingly showed the conversion of the methyl groups, as isotopically labeled CH4 was formed during all experiments. Based on these results, we considered several hypotheses about endogenously formed CH4 in humans, including physiological aspects and stress responses involving reactive oxygen species (ROS). While further and broader validation studies are needed, the results may unambiguously serve as a proof of concept for the endogenous formation of CH4 in humans via a radical-driven process. Furthermore, these results might encourage follow-up studies to decipher the potential physiological role of CH4 and its bioactivity in humans in more detail. Of particular importance is the potential to monitor CH4 as an oxidative stress biomarker if the observed large variability of CH4 in breath air is an indicator of physiological stress responses and immune reactions. Finally, the potential role of DMSO as a radical scavenger to counteract oxidative stress caused by ROS might be considered in the health sciences. DMSO has already been investigated for many years, but its potential positive role in medical use remains highly uncertain.
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Affiliation(s)
- Frank Keppler
- Institute of Earth Sciences, Heidelberg University, D-69120 Heidelberg, Germany
- Heidelberg Center for the Environment (HCE), Heidelberg University, D-69120 Heidelberg, Germany
| | - Mihály Boros
- Institute of Surgical Research, University of Szeged, H-6724 Szeged, Hungary
| | - Daniela Polag
- Institute of Earth Sciences, Heidelberg University, D-69120 Heidelberg, Germany
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2
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Ernst L, Steinfeld B, Barayeu U, Klintzsch T, Kurth M, Grimm D, Dick TP, Rebelein JG, Bischofs IB, Keppler F. Methane formation driven by reactive oxygen species across all living organisms. Nature 2022; 603:482-487. [PMID: 35264795 DOI: 10.1038/s41586-022-04511-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 02/03/2022] [Indexed: 11/09/2022]
Abstract
Methane (CH4), the most abundant hydrocarbon in the atmosphere, originates largely from biogenic sources1 linked to an increasing number of organisms occurring in oxic and anoxic environments. Traditionally, biogenic CH4 has been regarded as the final product of anoxic decomposition of organic matter by methanogenic archaea. However, plants2,3, fungi4, algae5 and cyanobacteria6 can produce CH4 in the presence of oxygen. Although methanogens are known to produce CH4 enzymatically during anaerobic energy metabolism7, the requirements and pathways for CH4 production by non-methanogenic cells are poorly understood. Here, we demonstrate that CH4 formation by Bacillus subtilis and Escherichia coli is triggered by free iron and reactive oxygen species (ROS), which are generated by metabolic activity and enhanced by oxidative stress. ROS-induced methyl radicals, which are derived from organic compounds containing sulfur- or nitrogen-bonded methyl groups, are key intermediates that ultimately lead to CH4 production. We further show CH4 production by many other model organisms from the Bacteria, Archaea and Eukarya domains, including in several human cell lines. All these organisms respond to inducers of oxidative stress by enhanced CH4 formation. Our results imply that all living cells probably possess a common mechanism of CH4 formation that is based on interactions among ROS, iron and methyl donors, opening new perspectives for understanding biochemical CH4 formation and cycling.
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Affiliation(s)
- Leonard Ernst
- BioQuant Center, Heidelberg University, Heidelberg, Germany. .,Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany. .,Institute of Earth Sciences, Heidelberg University, Heidelberg, Germany.
| | - Benedikt Steinfeld
- BioQuant Center, Heidelberg University, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany.,Zentrum für Molekulare Biologie Heidelberg (ZMBH), Heidelberg University, Heidelberg, Germany
| | - Uladzimir Barayeu
- Division of Redox Regulation, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Thomas Klintzsch
- Institute of Earth Sciences, Heidelberg University, Heidelberg, Germany.,Department for Plant Nutrition, Gießen University, Gießen, Germany
| | - Markus Kurth
- Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Dirk Grimm
- BioQuant Center, Heidelberg University, Heidelberg, Germany.,Department of Infectious Diseases/Virology, Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Tobias P Dick
- Division of Redox Regulation, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | | | - Ilka B Bischofs
- BioQuant Center, Heidelberg University, Heidelberg, Germany. .,Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany. .,Faculty of Biosciences, Heidelberg University, Heidelberg, Germany.
| | - Frank Keppler
- Institute of Earth Sciences, Heidelberg University, Heidelberg, Germany. .,Heidelberg Center for the Environment (HCE), Heidelberg University, Heidelberg, Germany.
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3
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Ye ZH, Ning K, Ander BP, Sun XJ. Therapeutic effect of methane and its mechanism in disease treatment. J Zhejiang Univ Sci B 2021; 21:593-602. [PMID: 32748575 DOI: 10.1631/jzus.b1900629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Methane is the simplest hydrocarbon, consisting of one carbon atom and four hydrogen atoms. It is abundant in marsh gas, livestock rumination, and combustible ice. Little is known about the use of methane in human disease treatment. Current research indicates that methane is useful for treating several diseases including ischemia and reperfusion injury, and inflammatory diseases. The mechanisms underlying the protective effects of methane appear primarily to involve anti-oxidation, anti-inflammation, and anti-apoptosis. In this review, we describe the beneficial effects of methane on different diseases, summarize possible mechanisms by which methane may act in these conditions, and discuss the purpose of methane production in hypoxic conditions. Then we propose several promising directions for the future research.
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Affiliation(s)
- Zhou-Heng Ye
- Department of Aviation and Diving Medicine, the Sixth Medical Center, General Hospital of People's Liberation Army, Beijing 100048, China
| | - Ke Ning
- Department of Navy Aviation Medicine, Faculty of Naval Medicine, the Naval Military Medical University, Shanghai 200433, China
| | - Bradley P Ander
- Department of Neurology, University of California at Davis, Sacramento, California, USA
| | - Xue-Jun Sun
- Department of Navy Aviation Medicine, Faculty of Naval Medicine, the Naval Military Medical University, Shanghai 200433, China
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4
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Methane-Rich Saline Alleviates CA/CPR Brain Injury by Inhibiting Oxidative Stress, Microglial Activation-Induced Inflammatory Responses, and ER Stress-Mediated Apoptosis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:8829328. [PMID: 33149813 PMCID: PMC7603629 DOI: 10.1155/2020/8829328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/20/2020] [Accepted: 09/25/2020] [Indexed: 12/21/2022]
Abstract
Brain injury induced by cardiac arrest/cardiopulmonary resuscitation (CA/CPR) is the leading cause of death among patients who have recovery of spontaneous circulation (ROSC). Inflammatory response, apoptosis, and oxidative stress are proven pathological mechanisms implicated in neuronal damage. Methane-rich saline (MRS) has been proven that exerts a beneficial protectiveness impact in several models of ischemia-reperfusion injury. The goal of this paper is to ascertain the role of MRS in CA/CPR-induced brain injury and its potential mechanisms. The tracheal intubation of Sprague-Dawley (SD) rats was clamped for 6 min to establish an asphyxiating cardiac arrest model. After that, chest compressions were applied; then, MRS or saline was administered immediately post-ROSC, the rats were sacrificed, and brain tissue was collected at the end of 6 hours. We observed that MRS treatment attenuated neuronal damage in the hippocampal CA1 region by inhibiting microglial activation, leading to a decrease in the overexpression of proinflammatory cytokines such as TNF-α, IL-6, and iNOS. The results also illustrated that MRS treatment diminished apoptosis in the hippocampal CA1 region , reduced the expression of apoptosis-associated proteins Bax and cleaved caspase9, and increased Bcl-2 expression, as well as inhibited the expression of endoplasmic reticulum (ER) stress pathway-related proteins GRP78, ATF4, and CHOP. Further findings showed that MRS treatment significantly attenuated hippocampal ROS and MDA levels and increased GSH and SOD antioxidant factor levels, which indicated that MRS treatment could inhibit oxidative stress. Our results suggest that MRS exerts a protective effect against CA/CPR brain injury, by inhibiting oxidative stress, microglial activation-induced inflammatory responses, and ER stress-mediated apoptosis.
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5
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Varga P, Vida N, Hartmann P, Szabó A, Mohácsi Á, Szabó G, Boros M, Tuboly E. Alternative methanogenesis - Methanogenic potential of organosulfur administration. PLoS One 2020; 15:e0236578. [PMID: 32730295 PMCID: PMC7392280 DOI: 10.1371/journal.pone.0236578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 07/08/2020] [Indexed: 11/23/2022] Open
Affiliation(s)
- Petra Varga
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Noémi Vida
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Petra Hartmann
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Anna Szabó
- MTA-SZTE Research Group on Photoacoustic Spectroscopy, University of Szeged, Szeged, Hungary
| | - Árpád Mohácsi
- MTA-SZTE Research Group on Photoacoustic Spectroscopy, University of Szeged, Szeged, Hungary
| | - Gábor Szabó
- MTA-SZTE Research Group on Photoacoustic Spectroscopy, University of Szeged, Szeged, Hungary
| | - Mihály Boros
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Eszter Tuboly
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
- * E-mail:
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6
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Li L, Wei S, Shen W. The role of methane in plant physiology: a review. PLANT CELL REPORTS 2020; 39:171-179. [PMID: 31646372 DOI: 10.1007/s00299-019-02478-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/18/2019] [Accepted: 10/03/2019] [Indexed: 05/05/2023]
Abstract
Methane (CH4), one of the most important greenhouse gases, has conventionally been considered as a physiologic inert gas. However, this perspective has been challenged by the observation that CH4 has diverse biological functions in animals, such as anti-inflammatory, antioxidant, and anti-apoptosis. Meanwhile, it has now been identified as a possible candidate of gaseous signaling molecule in plants, although its biosynthetic and metabolic pathways as well as the mechanism(s) of CH4 signaling have not fully understood yet. This paper aims to review the available evidence for the biological roles of CH4 in regulating plant physiology. Although currently available reports do not fully support the notion of CH4 as a gasotransmitter, they do show that CH4 might be produced by an aerobic, non-microbial pathway from plants, and plays important roles in enhancing plant tolerance against abiotic stresses, such as salinity, drought, heavy metal exposure, and promoting root development, as well as delaying senescence and browning. Further results showed that CH4 could interact with reactive oxygen species (ROS), other gaseous signaling molecules [e.g., nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S)], and glutathione (GSH). These reports thus support the idea that plant-produced CH4 might be a component of a survival strategy of plants. Finally, the possibility of CH4 application in agriculture is preliminarily discussed.
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Affiliation(s)
- Longna Li
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Siqi Wei
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wenbiao Shen
- Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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7
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Bižić M, Klintzsch T, Ionescu D, Hindiyeh MY, Günthel M, Muro-Pastor AM, Eckert W, Urich T, Keppler F, Grossart HP. Aquatic and terrestrial cyanobacteria produce methane. SCIENCE ADVANCES 2020; 6:eaax5343. [PMID: 31998836 PMCID: PMC6962044 DOI: 10.1126/sciadv.aax5343] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 11/19/2019] [Indexed: 05/08/2023]
Abstract
Evidence is accumulating to challenge the paradigm that biogenic methanogenesis, considered a strictly anaerobic process, is exclusive to archaea. We demonstrate that cyanobacteria living in marine, freshwater, and terrestrial environments produce methane at substantial rates under light, dark, oxic, and anoxic conditions, linking methane production with light-driven primary productivity in a globally relevant and ancient group of photoautotrophs. Methane production, attributed to cyanobacteria using stable isotope labeling techniques, was enhanced during oxygenic photosynthesis. We suggest that the formation of methane by cyanobacteria contributes to methane accumulation in oxygen-saturated marine and limnic surface waters. In these environments, frequent cyanobacterial blooms are predicted to further increase because of global warming potentially having a direct positive feedback on climate change. We conclude that this newly identified source contributes to the current natural methane budget and most likely has been producing methane since cyanobacteria first evolved on Earth.
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Affiliation(s)
- M. Bižić
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhuette 2, D-16775 Stechlin, Germany
- Corresponding author. (M.B.); (H.-P.G.)
| | - T. Klintzsch
- Institute of Earth Sciences, Biogeochemistry Group, Heidelberg University, Heidelberg, Germany
| | - D. Ionescu
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhuette 2, D-16775 Stechlin, Germany
| | - M. Y. Hindiyeh
- Department of Water and Environmental Engineering, German Jordanian University, Amman, Jordan
| | - M. Günthel
- Department of Biosciences, Swansea University, SA2 8PP Swansea, UK
- Medical University of Gdańsk, Department of International Research Agenda 3P–Medicine, Marii Skłodowskiej-Curie 3a, 80-210 Gdańsk, Poland
| | - A. M. Muro-Pastor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Sevilla, Spain
| | - W. Eckert
- Israel Oceanographic and Limnological Research, Yigal Allon Kinneret Limnological Laboratory, Migdal 14650, Israel
| | - T. Urich
- Institute of Microbiology, Center for Functional Genomics, University of Greifswald, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - F. Keppler
- Institute of Earth Sciences, Biogeochemistry Group, Heidelberg University, Heidelberg, Germany
- Heidelberg Center for the Environment (HCE), Heidelberg University, 69120 Heidelberg, Germany
| | - H.-P. Grossart
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhuette 2, D-16775 Stechlin, Germany
- Institute of Biochemistry and Biology, Potsdam University, Maulbeerallee 2, 14469 Potsdam, Germany
- Corresponding author. (M.B.); (H.-P.G.)
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8
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Boros M, Keppler F. Methane Production and Bioactivity-A Link to Oxido-Reductive Stress. Front Physiol 2019; 10:1244. [PMID: 31611816 PMCID: PMC6776796 DOI: 10.3389/fphys.2019.01244] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/10/2019] [Indexed: 12/15/2022] Open
Abstract
Biological methane formation is associated with anoxic environments and the activity of anaerobic prokaryotes (Archaea). However, recent studies have confirmed methane release from eukaryotes, including plants, fungi, and animals, even in the absence of microbes and in the presence of oxygen. Furthermore, it was found that aerobic methane emission in plants is stimulated by a variety of environmental stress factors, leading to reactive oxygen species (ROS) generation. Further research presented evidence that molecules with sulfur and nitrogen bonded methyl groups such as methionine or choline are carbon precursors of aerobic methane formation. Once generated, methane is widely considered to be physiologically inert in eukaryotes, but several studies have found association between mammalian methanogenesis and gastrointestinal (GI) motility changes. In addition, a number of recent reports demonstrated anti-inflammatory potential for exogenous methane-based approaches in model anoxia-reoxygenation experiments. It has also been convincingly demonstrated that methane can influence the downstream effectors of transiently increased ROS levels, including mitochondria-related pro-apoptotic pathways during ischemia-reperfusion (IR) conditions. Besides, exogenous methane can modify the outcome of gasotransmitter-mediated events in plants, and it appears that similar mechanism might be active in mammals as well. This review summarizes the relevant literature on methane-producing processes in eukaryotes, and the available results that underscore its bioactivity. The current evidences suggest that methane liberation and biological effectiveness are both linked to cellular redox regulation. The data collectively imply that exogenous methane influences the regulatory mechanisms and signaling pathways involved in oxidative and nitrosative stress responses, which suggests a modulator role for methane in hypoxia-linked pathologies.
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Affiliation(s)
- Mihály Boros
- Institute of Surgical Research, Interdisciplinary Centre of Excellence, University of Szeged, Szeged, Hungary
| | - Frank Keppler
- Institute of Earth Sciences, Heidelberg University, Heidelberg, Germany
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9
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Zhao RZ, Jiang S, Ru NY, Jiao B, Yu ZB. Comparison of hypoxic effects induced by chemical and physical hypoxia on cardiomyocytes. Can J Physiol Pharmacol 2019; 97:980-988. [PMID: 31136722 DOI: 10.1139/cjpp-2019-0092] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The degree and duration of chemical hypoxia induced by sodium dithionite (Na2S2O4) have not been reported. It is not yet clear how much reduction in the O2 concentration (physical hypoxia) can lead to hypoxia in cultured cardiomyocytes. In this study, oxygen microelectrodes were used to measure changes in the O2 concentration in media containing different concentrations of Na2S2O4. Then, hypoxic effects of 0.8, 1.0, and 2.0 mM Na2S2O4 or 1%, 3%, and 5% O2 in cultured cardiomyocytes from neonatal rats were observed and compared. The results showed that the O2 concentration failed to remain constant by Na2S2O4 treatment during the 180-minute observation period. Only the 2.0 mM Na2S2O4 group significantly increased the expression of hypoxia-inducible factor 1α (HIF-1α) and hypoxic responses. Notably, 3% O2 only significantly increased the expression of HIF-1α in cardiomyocytes, while 1% O2 not only increased the expression of HIF-1α but also increased the apoptotic rate in cardiomyocytes. These results suggest that Na2S2O4 is not suitable for establishing a hypoxic model in cultured neonatal rat cardiomyocytes, and neonatal rat cardiomyocytes cultured at or below 1% O2 induced significant hypoxic effects, which can be used as a starting O2 concentration for establishing a hypoxic cell model.
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Affiliation(s)
- Ru-Zhou Zhao
- Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China
| | - Shuai Jiang
- Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China
| | - Ning-Yu Ru
- Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China.,Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China
| | - Bo Jiao
- Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China.,Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China
| | - Zhi-Bin Yu
- Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China.,Department of Aerospace Physiology, Fourth Military Medical University, Key Laboratory of Aerospace Medicine, Ministry of China, Xi'an 710032, China
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10
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Szűcs S, Bari G, Ugocsai M, Lashkarivand RA, Lajkó N, Mohácsi Á, Szabó A, Kaszaki J, Boros M, Érces D, Varga G. Detection of Intestinal Tissue Perfusion by Real-Time Breath Methane Analysis in Rat and Pig Models of Mesenteric Circulatory Distress. Crit Care Med 2019; 47:e403-e411. [PMID: 30985462 DOI: 10.1097/ccm.0000000000003659] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Methane (CH4) breath test is an established diagnostic method for gastrointestinal functional disorders. Our aim was to explore the possible link between splanchnic circulatory changes and exhaled CH4 in an attempt to recognize intestinal perfusion failure. DESIGN Randomized, controlled in vivo animal study. SETTING University research laboratory. SUBJECTS Anesthetized, ventilated Sprague-Dawley rats (280 ± 30 g) and Vietnamese minipigs (31 ± 7 kg). INTERVENTIONS In the first series, CH4 was administered intraluminally into the ileum before 45 minutes mesenteric ischemia or before reperfusion in non-CH4 producer rats to test the appearance of the gas in the exhaled air. In the porcine experiments, the superior mesenteric artery was gradually obstructed during consecutive, 30-minute flow reductions and 30-minute reperfusions achieving complete occlusion after four cycles (n = 6), or nonocclusive mesenteric ischemia was induced by pericardial tamponade (n = 12), which decreased superior mesenteric artery flow from 351 ± 55 to 182 ± 67 mL/min and mean arterial pressure from 96.7 ± 18.2 to 41.5 ± 4.6 mm Hg for 60 minutes. MEASUREMENTS AND MAIN RESULTS Macrohemodynamics were monitored continuously; RBC velocity of the ileal serosa or mucosa was recorded by intravital videomicroscopy. The concentration of exhaled CH4 was measured online simultaneously with high-sensitivity photoacoustic spectroscopy. The intestinal flow changes during the occlusion-reperfusion phases were accompanied by parallel changes in breath CH4 output. Also in cardiac tamponade-induced nonocclusive intestinal ischemia, the superior mesenteric artery flow and RBC velocity correlated significantly with parallel changes in CH4 concentration in the exhaled air (Pearson's r = 0.669 or r = 0.632, respectively). CONCLUSIONS we report a combination of in vivo experimental data on a close association of an exhaled endogenous gas with acute mesenteric macro- and microvascular flow changes. Breath CH4 analysis may offer a noninvasive approach to follow the status of the splanchnic circulation.
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Affiliation(s)
- Szilárd Szűcs
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Gábor Bari
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
- Department of Cardiac Surgery, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Melinda Ugocsai
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Reza Ali Lashkarivand
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Norbert Lajkó
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Árpád Mohácsi
- MTA-SZTE Research Group on Photoacoustic Spectroscopy, Szeged, Hungary
| | - Anna Szabó
- Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - József Kaszaki
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Mihály Boros
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Dániel Érces
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Gabriella Varga
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
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11
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Comba P, Faltermeier D, Gieger S, Keppler F, Schöler HF, Schroll M. Iron catalyzed demethylation of acetic acid*. J COORD CHEM 2018. [DOI: 10.1080/00958972.2018.1490414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Peter Comba
- Anorganisch-Chemisches Institut and Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany
| | - Dieter Faltermeier
- Anorganisch-Chemisches Institut and Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany
| | - Sascha Gieger
- Institute of Earth Sciences and Heidelberg Center for the Environment (HCE), Heidelberg University, Heidelberg, Germany
| | - Frank Keppler
- Institute of Earth Sciences and Heidelberg Center for the Environment (HCE), Heidelberg University, Heidelberg, Germany
| | - Heinz Friedrich Schöler
- Institute of Earth Sciences and Heidelberg Center for the Environment (HCE), Heidelberg University, Heidelberg, Germany
| | - Moritz Schroll
- Institute of Earth Sciences and Heidelberg Center for the Environment (HCE), Heidelberg University, Heidelberg, Germany
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12
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Polag D, Keppler F. Long-term monitoring of breath methane. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 624:69-77. [PMID: 29247906 DOI: 10.1016/j.scitotenv.2017.12.097] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/08/2017] [Accepted: 12/08/2017] [Indexed: 06/07/2023]
Abstract
In recent years, methane as a component of exhaled human breath has been considered as a potential bioindicator providing information on microbial activity in the intestinal tract. Several studies indicated a relationship between breath methane status and specific gastrointestinal disease. So far, almost no attention has been given to the temporal variability of breath methane production by individual persons. Thus here, for the first time, long-term monitoring was carried out measuring breath methane of three volunteers over periods between 196 and 1002days. Results were evaluated taking into consideration the health status and specific medical intervention events for each individual during the monitoring period, and included a gastroscopy procedure, a vaccination, a dietary change, and chelate therapy. As a major outcome, breath methane mixing ratios show considerable variability within a person-specific range of values. Interestingly, decreased breath methane production often coincided with gastrointestinal complaints whereas influenza infections were mostly accompanied by increased breath methane production. A gastroscopic examination as well as a change to a low-fructose diet led to a dramatic shift of methane mixing ratios from high to low methane production. In contrast, a typhus vaccination as well as single chelate injections resulted in significant short-term methane peaks. Thus, this study clearly shows that humans can change from high to low methane emitters and vice versa within relatively short time periods. In the case of low to medium methane emitters the increase observed in methane mixing ratios, likely resulting from immune reactions and inflammatory processes, might indicate non-microbial methane formation under aerobic conditions. Although detailed reaction pathways are not yet known, aerobic methane formation might be related to cellular oxidative-reductive stress reactions. However, a detailed understanding of the pathways involved in human methane formation is necessary to enable comprehensive interpretation of methane breath levels.
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Affiliation(s)
- Daniela Polag
- Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 236, D-69120 Heidelberg, Germany.
| | - Frank Keppler
- Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 236, D-69120 Heidelberg, Germany
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13
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Mészáros AT, Szilágyi ÁL, Juhász L, Tuboly E, Érces D, Varga G, Hartmann P. Mitochondria As Sources and Targets of Methane. Front Med (Lausanne) 2017; 4:195. [PMID: 29181377 PMCID: PMC5693848 DOI: 10.3389/fmed.2017.00195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/25/2017] [Indexed: 12/14/2022] Open
Abstract
This review summarizes the current knowledge on the role of mitochondria in the context of hypoxic cell biology, while providing evidence of how these mechanisms are modulated by methane (CH4). Recent studies have unambiguously confirmed CH4 bioactivity in various in vitro and in vivo experimental models and established the possibility that CH4 can affect many aspects of mitochondrial physiology. To date, no specific binding of CH4 to any enzymes or receptors have been reported, and it is probable that many of its effects are related to physico-chemical properties of the non-polar molecule. (i) Mitochondria themselves can be sources of endogenous CH4 generation under oxido-reductive stress conditions; chemical inhibition of the mitochondrial electron transport chain with site-specific inhibitors leads to increased formation of CH4 in eukaryote cells, in plants, and in animals. (ii) Conventionally believed as physiologically inert, studies cited in this review demonstrate that exogenous CH4 modulates key events of inflammation. The anti-apoptotic effects of exogenously administered CH4 are also recognized, and these properties also suggest that CH4-mediated intracellular signaling is closely associated with mitochondria. (iii) Mitochondrial substrate oxidation is coupled with the reduction of molecular oxygen, thus providing energy for cellular metabolism. Interestingly, recent in vivo studies have shown improved basal respiration and modulated mitochondrial oxidative phosphorylation by exogenous CH4. Overall, these data suggest that CH4 liberation and effectiveness in eukaryotes are both linked to hypoxic events and redox regulation and support the notion that CH4 has therapeutic roles in mammalian pathophysiologies.
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Affiliation(s)
| | | | - László Juhász
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Eszter Tuboly
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Dániel Érces
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Gabriella Varga
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Petra Hartmann
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
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Microbe-mitochondrion crosstalk and health: An emerging paradigm. Mitochondrion 2017; 39:20-25. [PMID: 28838618 DOI: 10.1016/j.mito.2017.08.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 07/07/2017] [Accepted: 08/15/2017] [Indexed: 02/07/2023]
Abstract
Human mitochondria are descendants of microbes and altered mitochondrial function has been implicated in processes ranging from ageing to diabetes. Recent work has highlighted the importance of gut microbial communities in human health and disease. While the spotlight has been on the influence of such communities on the human immune system and the extraction of calories from otherwise indigestible food, an important but less investigated link between the microbes and mitochondria remains unexplored. Microbial metabolites including short chain fatty acids as well as other molecules such as pyrroloquinoline quinone, fermentation gases, and modified fatty acids influence mitochondrial function. This review focuses on the known direct and indirect effects of microbes upon mitochondria and speculates regarding additional links for which there is circumstantial evidence. Overall, while there is compelling evidence that a microbiota-mitochondria link exists, explicit and holistic mechanistic studies are warranted to advance this nascent field.
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Methane enhances aluminum resistance in alfalfa seedlings by reducing aluminum accumulation and reestablishing redox homeostasis. Biometals 2017; 30:719-732. [DOI: 10.1007/s10534-017-0040-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 07/31/2017] [Indexed: 10/19/2022]
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Excessive alcohol consumption induces methane production in humans and rats. Sci Rep 2017; 7:7329. [PMID: 28779149 PMCID: PMC5544731 DOI: 10.1038/s41598-017-07637-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 06/30/2017] [Indexed: 12/04/2022] Open
Abstract
Various studies have established the possibility of non-bacterial methane (CH4) generation in oxido-reductive stress conditions in plants and animals. Increased ethanol input is leading to oxido-reductive imbalance in eukaryotes, thus our aim was to provide evidence for the possibility of ethanol-induced methanogenesis in non-CH4 producer humans, and to corroborate the in vivo relevance of this pathway in rodents. Healthy volunteers consumed 1.15 g/kg/day alcohol for 4 days and the amount of exhaled CH4 was recorded by high sensitivity photoacoustic spectroscopy. Additionally, Sprague-Dawley rats were allocated into control, 1.15 g/kg/day and 2.7 g/kg/day ethanol-consuming groups to detect the whole-body CH4 emissions and mitochondrial functions in liver and hippocampus samples with high-resolution respirometry. Mitochondria-targeted L-alpha-glycerylphosphorylcholine (GPC) can increase tolerance to liver injury, thus the effects of GPC supplementations were tested in further ethanol-fed groups. Alcohol consumption was accompanied by significant CH4 emissions in both human and rat series of experiments. 2.7 g/kg/day ethanol feeding reduced the oxidative phosphorylation capacity of rat liver mitochondria, while GPC significantly decreased the alcohol-induced CH4 formation and hepatic mitochondrial dysfunction as well. These data demonstrate a potential for ethanol to influence human methanogenesis, and suggest a biomarker role for exhaled CH4 in association with mitochondrial dysfunction.
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Benzing K, Comba P, Martin B, Pokrandt B, Keppler F. Nonheme Iron‐Oxo‐Catalyzed Methane Formation from Methyl Thioethers: Scope, Mechanism, and Relevance for Natural Systems. Chemistry 2017; 23:10465-10472. [DOI: 10.1002/chem.201701986] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Kathrin Benzing
- Institute of Inorganic ChemistryHeidelberg University Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Peter Comba
- Institute of Inorganic Chemistry and Interdisciplinary Center for Scientific Computing (IWR)Heidelberg University Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Bodo Martin
- Institute of Inorganic ChemistryHeidelberg University Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Bianca Pokrandt
- Institute of Inorganic ChemistryHeidelberg University Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Frank Keppler
- Institute of Earth Sciences and Heidelberg Center for the Environment (HCE)Heidelberg University Im Neuenheimer Feld 236 69120 Heidelberg Germany
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Mészáros AT, Büki T, Fazekas B, Tuboly E, Horváth K, Poles MZ, Szűcs S, Varga G, Kaszaki J, Boros M. Inhalation of methane preserves the epithelial barrier during ischemia and reperfusion in the rat small intestine. Surgery 2017; 161:1696-1709. [PMID: 28242089 DOI: 10.1016/j.surg.2016.12.040] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/22/2016] [Accepted: 12/29/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND Methane is part of the gaseous environment of the intestinal lumen. The purpose of this study was to elucidate the bioactivity of exogenous methane on the intestinal barrier function in an antigen-independent model of acute inflammation. METHODS Anesthetized rats underwent sham operation or 45-min occlusion of the superior mesenteric artery. A normoxic methane (2.2%)-air mixture was inhaled for 15 min at the end of ischemia and at the beginning of a 60-min or 180-min reperfusion. The integrity of the epithelial barrier of the ileum was assessed by determining the lumen-to-blood clearance of fluorescent dextran, while microvascular permeability changes were detected by the Evans blue technique. Tissue levels of superoxide, nitrotyrosine, myeloperoxidase, and endothelin-1 were measured, the superficial mucosal damage was visualized and quantified, and the serosal microcirculation and mesenteric flow was recorded. Erythrocyte deformability and aggregation were tested in vitro. RESULTS Reperfusion significantly increased epithelial permeability, worsened macro- and microcirculation, increased the production of proinflammatory mediators, and resulted in a rapid loss of the epithelium. Exogenous normoxic methane inhalation maintained the superficial mucosal structure, decreased epithelial permeability, and improved local microcirculation, with a decrease in reactive oxygen and nitrogen species generation. Both the deformability and aggregation of erythrocytes improved with incubation of methane. CONCLUSION Normoxic methane decreases the signs of oxidative and nitrosative stress, improves tissue microcirculation, and thus appears to modulate the ischemia-reperfusion-induced epithelial permeability changes. These findings suggest that the administration of exogenous methane may be a useful strategy for maintaining the integrity of the mucosa sustaining an oxido-reductive attack.
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Affiliation(s)
- András T Mészáros
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - Tamás Büki
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - Borbála Fazekas
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - Eszter Tuboly
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - Kitti Horváth
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - Marietta Z Poles
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - Szilárd Szűcs
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - Gabriella Varga
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - József Kaszaki
- University of Szeged, Institute of Surgical Research, Szeged, Hungary
| | - Mihály Boros
- University of Szeged, Institute of Surgical Research, Szeged, Hungary.
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Wang L, Yao Y, He R, Meng Y, Li N, Zhang D, Xu J, Chen O, Cui J, Bian J, Zhang Y, Chen G, Deng X. Methane ameliorates spinal cord ischemia-reperfusion injury in rats: Antioxidant, anti-inflammatory and anti-apoptotic activity mediated by Nrf2 activation. Free Radic Biol Med 2017; 103:69-86. [PMID: 28007572 DOI: 10.1016/j.freeradbiomed.2016.12.014] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 11/14/2016] [Accepted: 12/11/2016] [Indexed: 11/28/2022]
Abstract
Methane is reported to have antioxidant, anti-inflammatory and anti-apoptotic properties. We investigated the potential neuroprotective effects of methane-rich saline (MS) on spinal cord ischemia-reperfusion injury and determined that its therapeutic benefits are associated with the activation of nuclear factor erythroid 2-related factor 2 (Nrf2). Rats received 9min of spinal cord ischemia induced by occlusion of the descending thoracic aorta plus systemic hypotension followed by a single MS treatment (10ml/kg, ip) and 72h reperfusion. MS treatment attenuated motor sensory deficits and produced high concentrations of methane in spinal cords during reperfusion, which increased Nrf2 expression and transcriptional activity in neurons, microglia and astrocytes in the ventral, intermediate and dorsal gray matter of lumbar segments. Heme oxygenase-1, superoxide dismutase, catalase and glutathione were upregulated; and glutathione disulfide, superoxide, hydrogen peroxide, malondialdehyde, 8-hydroxy-2-deoxyguanosine and 3-nitrotyrosine were downregulated in MS-treated spinal cords. MS treatment reduced neuronal apoptosis in gray matter zones, which was consistent with the suppression of cytochrome c release to the cytosol from the mitochondria and the activation of caspase-9 and -3. Throughout the gray matter, the activation of microglia and astrocytes was inhibited; the nuclear accumulation of phosphorylated nuclear factor-kappa B p65 was reduced; and tumor necrosis factor α, interleukin 1β, chemokine (C-X-C motif) ligand 1, intercellular adhesion molecule 1 and myeloperoxidase were decreased. MS treatment attenuated blood-spinal cord barrier dysfunction by preventing the expression and activity of matrix metallopeptidase-9 and disrupting tight junction proteins. Consecutive intrathecal injection of specific siRNAs targeting Nrf2 at 24-h intervals 3 days before ischemia reduced the beneficial effects of MS. Our data indicate that MS treatment prevents IR-induced spinal cord damage via antioxidant, anti-inflammatory and anti-apoptotic activities that involve the activation of Nrf2 signaling. Thus, methane may serve as a novel promising therapeutic agent for treating ischemic spinal cord injury.
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Affiliation(s)
- Liping Wang
- Department of Anesthesiology, Fuzhou General Hospital of PLA, Fuzhou 350025, Fujian Province, People's Republic of China
| | - Ying Yao
- Department of Anesthesiology and Intensive Care Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Rong He
- Department of Anesthesiology, Xinyi People's Hospital, Xinyi 221400, Jiangsu Province, People's Republic of China
| | - Yan Meng
- Department of Anesthesiology and Intensive Care Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Na Li
- Department of Anesthesiology and Intensive Care Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Dan Zhang
- Department of Anesthesiology and Intensive Care Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Jiajun Xu
- Department of Diving and Hyperbaric Medicine, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Ouyang Chen
- Department of Navy Aviation Medicine, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Jin Cui
- Graduate Management Unit, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Jinjun Bian
- Department of Anesthesiology and Intensive Care Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Yan Zhang
- Department of Anesthesiology and Intensive Care Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Guozhong Chen
- Department of Anesthesiology, Fuzhou General Hospital of PLA, Fuzhou 350025, Fujian Province, People's Republic of China.
| | - Xiaoming Deng
- Department of Anesthesiology and Intensive Care Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China.
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Strifler G, Tuboly E, Görbe A, Boros M, Pécz D, Hartmann P. Targeting Mitochondrial Dysfunction with L-Alpha Glycerylphosphorylcholine. PLoS One 2016; 11:e0166682. [PMID: 27861548 PMCID: PMC5115775 DOI: 10.1371/journal.pone.0166682] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/02/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND We hypothesized that L-alpha-glycerylphosphorylcholine (GPC), a deacylatedphosphatidylcholine derivative, can influence the mitochondrial respiratory activity and in this way, may exert tissue protective effects. METHODS Rat liver mitochondria were examined with high-resolution respirometry to analyze the effects of GPC on the electron transport chain in normoxic and anoxic conditions. Besides, Sprague-Dawley rats were subjected to sham operation or standardized liver ischemia-reperfusion (IR), with or without GPC administration. The reduced glutathione (GSH) and oxidized glutathione disulfide (GSSG), the tissue myeloperoxidase, xanthine oxidoreductase and NADPH oxidases activities were measured. Tissue malondialdehyde and nitrite/nitrate formation, together with blood superoxide and hydrogen-peroxide production were assessed. RESULTS GPC increased the efficacy of complex I-linked mitochondrial oxygen consumption, with significantly lower in vitro leak respiration. Mechanistically, liver IR injury was accompanied by deteriorated mitochondrial respiration and enhanced ROS production and, as a consequence, by significantly increased inflammatory enzyme activities. GPC administration decreased the inflammatory activation in line with the reduced oxidative and nitrosative stress markers. CONCLUSION GPC, by preserving the mitochondrial complex I function respiration, reduced the biochemical signs of oxidative stress after an IR episode. This suggests that GPC is a mitochondria-targeted compound that indirectly suppresses the activity of major intracellular superoxide-generating enzymes.
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Affiliation(s)
- Gerda Strifler
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Eszter Tuboly
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Anikó Görbe
- Department of Biochemistry, University of Szeged, Szeged, Hungary
| | - Mihály Boros
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Daniella Pécz
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Petra Hartmann
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
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Khan I, Ali A, Akhter MA, Naeem N, Chotani MA, Mustafa T, Salim A. Preconditioning of mesenchymal stem cells with 2,4-dinitrophenol improves cardiac function in infarcted rats. Life Sci 2016; 162:60-9. [PMID: 27543341 DOI: 10.1016/j.lfs.2016.08.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 07/05/2016] [Accepted: 08/14/2016] [Indexed: 12/11/2022]
Abstract
AIMS The aim of this study is to determine if preconditioning of bone marrow derived mesenchymal stem cells (MSCs) with 2,4-dinitrophenol (DNP) improves survival of transplanted stem cells in a rat model of myocardial infarction (MI), and to asses if this strategy has measurable impact on cardiac function. MAIN METHODS MSCs were preconditioned with DNP. In vitro cell adhesion assay and qRT-PCR were performed to analyze the expression of genes involved in cardiomyogenesis, cell adhesion and angiogenesis. MI was produced by occlusion of left anterior descending coronary artery. One million cells were transplanted by intramyocardial injection into the infarcted myocardium. Echocardiography was performed after two and four weeks of cellular transplantation. Hearts were harvested after four weeks and processed for histological analysis. KEY FINDINGS DNP treated MSCs adhered to the surface more (p<0.001) as compared to the normal MSCs. Gene expression levels were significantly upregulated in case of DNP treatment. The number of viable MSCs was more (p<0.001) in animals that received DNP treated MSCs, leading to significant improvement in cardiac function. Histological analysis revealed significant reduction in scar formation (p<0.001), maintenance of left ventricular wall thickness (p<0.001), and increased angiogenesis (p<0.01). SIGNIFICANCE The study evidenced for the first time that MSCs preconditioned with DNP improved cardiac function after transplantation. This can be attributed to improved survival, homing, adhesion, and cardiomyogenic and angiogenic differentiation of DNP treated MSCs in vivo.
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Affiliation(s)
- Irfan Khan
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, 75270 Karachi, Pakistan
| | - Anwar Ali
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, 75270 Karachi, Pakistan; Department of Physiology, University of Karachi, 75270 Karachi, Pakistan
| | - Muhammad Aleem Akhter
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, 75270 Karachi, Pakistan
| | - Nadia Naeem
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, 75270 Karachi, Pakistan
| | - Maqsood Ahmed Chotani
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, 75270 Karachi, Pakistan; Center for Cardiovascular & Pulmonary Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Tuba Mustafa
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, 75270 Karachi, Pakistan
| | - Asmat Salim
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, 75270 Karachi, Pakistan.
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Effects of Methane-Rich Saline on the Capability of One-Time Exhaustive Exercise in Male SD Rats. PLoS One 2016; 11:e0150925. [PMID: 26942576 PMCID: PMC4778848 DOI: 10.1371/journal.pone.0150925] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/22/2016] [Indexed: 12/05/2022] Open
Abstract
Purpose To explore the effects of methane-rich saline (CH4 saline) on the capability of one-time exhaustive exercise in male SD rats. Methods Thirty rats were equally divided into to three groups at random: control group (C), placebo group (P) and methane saline group (M). Rats in M group underwent intraperitoneal injection of CH4 saline, and the other two groups simultaneously underwent intraperitoneal injection of normal saline. Then, the exercise capability of rats was tested through one-time exhaustive treadmill exercise except C group. Exercise time and body weight were recorded before and after one-time exhaustive exercise. After exhaustive exercise, the blood and gastrocnemius samples were collected from all rats to detect biochemical parameters in different methods. Results It was found that the treadmill running time was significantly longer in rats treated with CH4 saline. At the same time, CH4 saline reduced the elevation of LD and UN in blood caused by one-time exhaustive exercise. The low level of blood glucose induced by exhaustive exercise was also normalized by CH4 saline. Also CH4 saline lowered the level of CK in plasma. Furthermore, this research indicated that CH4 saline markedly increased the volume of T-AOC in plasma and alleviated the peak of TNF-α in both plasma and gastrocnemius. From H&E staining, CH4 saline effectively improved exercise-induced structural damage in gastrocnemius. Conclusions CH4 saline could enhance exercise capacity in male SD rats through increase of glucose aerobic oxidation, improvement of metabolic clearance and decrease of exhaustive exercise-induced gastrocnemius injury.
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Keppler F, Schiller A, Ehehalt R, Greule M, Hartmann J, Polag D. Stable isotope and high precision concentration measurements confirm that all humans produce and exhale methane. J Breath Res 2016; 10:016003. [PMID: 26824393 DOI: 10.1088/1752-7155/10/1/016003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Mammalian formation of methane (methanogenesis) is widely considered to occur exclusively by anaerobic microbial activity in the gastrointestinal tract. Approximately one third of humans, depending on colonization of the gut by methanogenic archaea, are considered methane producers based on the classification terminology of high and low emitters. In this study laser absorption spectroscopy was used to precisely measure concentrations and stable carbon isotope signatures of exhaled methane in breath samples from 112 volunteers with an age range from 1 to 80 years. Here we provide analytical evidence that volunteers exhaled methane levels were significantly above background (inhaled) air. Furthermore, stable carbon isotope values of the exhaled methane unambiguously confirmed that this gas was produced by all of the human subjects studied. Based on the emission and stable carbon isotope patterns of various age groups we hypothesize that next to microbial sources in the gastrointestinal tracts there might be other, as yet unidentified, processes involved in methane formation supporting the idea that humans might also produce methane endogenously in cells. Finally we suggest that stable isotope measurements of volatile organic compounds such as methane might become a useful tool in future medical research diagnostic programs.
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Affiliation(s)
- Frank Keppler
- Institute of Earth Sciences, University of Heidelberg, Im Neuenheimer Feld 234-236, 69120 Heidelberg, Germany. Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany. Heidelberg Center for the Environment (HCE), Ruprecht Karls University Heidelberg, D-69120 Heidelberg, Germany
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Strifler G, Tuboly E, Szél E, Kaszonyi E, Cao C, Kaszaki J, Mészáros A, Boros M, Hartmann P. Inhaled Methane Limits the Mitochondrial Electron Transport Chain Dysfunction during Experimental Liver Ischemia-Reperfusion Injury. PLoS One 2016; 11:e0146363. [PMID: 26741361 PMCID: PMC4720186 DOI: 10.1371/journal.pone.0146363] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 12/16/2015] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Methanogenesis can indicate the fermentation activity of the gastrointestinal anaerobic flora. Methane also has a demonstrated anti-inflammatory potential. We hypothesized that enriched methane inhalation can influence the respiratory activity of the liver mitochondria after an ischemia-reperfusion (IR) challenge. METHODS The activity of oxidative phosphorylation system complexes was determined after in vitro methane treatment of intact liver mitochondria. Anesthetized Sprague-Dawley rats subjected to standardized 60-min warm hepatic ischemia inhaled normoxic air (n = 6) or normoxic air containing 2.2% methane, from 50 min of ischemia and throughout the 60-min reperfusion period (n = 6). Measurement data were compared with those on sham-operated animals (n = 6 each). Liver biopsy samples were subjected to high-resolution respirometry; whole-blood superoxide and hydrogen peroxide production was measured; hepatocyte apoptosis was detected with TUNEL staining and in vivo fluorescence laser scanning microscopy. RESULTS Significantly decreased complex II-linked basal respiration was found in the normoxic IR group at 55 min of ischemia and a lower respiratory capacity (~60%) and after 5 min of reperfusion. Methane inhalation preserved the maximal respiratory capacity at 55 min of ischemia and significantly improved the basal respiration during the first 30 min of reperfusion. The IR-induced cytochrome c activity, reactive oxygen species (ROS) production and hepatocyte apoptosis were also significantly reduced. CONCLUSIONS The normoxic IR injury was accompanied by significant functional damage of the inner mitochondrial membrane, increased cytochrome c activity, enhanced ROS production and apoptosis. An elevated methane intake confers significant protection against mitochondrial dysfunction and reduces the oxidative damage of the hepatocytes.
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Affiliation(s)
- Gerda Strifler
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Eszter Tuboly
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Edit Szél
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Enikő Kaszonyi
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Chun Cao
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - József Kaszaki
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - András Mészáros
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Mihály Boros
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Petra Hartmann
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
- * E-mail:
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Boros M, Tuboly E, Mészáros A, Amann A. The role of methane in mammalian physiology-is it a gasotransmitter? J Breath Res 2015; 9:014001. [PMID: 25624411 DOI: 10.1088/1752-7155/9/1/014001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mammalian methanogenesis is widely considered to be an exclusive sign of anaerobic microbial activity in the gastrointestinal tract. This commonly held view was challenged, however, when in vitro and in vivo investigations demonstrated the possibility of nonmicrobial methane formation in aerobic organisms, in plants and animals. The aim of this review is to discuss the available literature data on the biological role of methane. When we evaluate the significance of methane generation in the mammalian physiology, the question may be examined: is it a gas mediator? Overall the data do not fully support the gasotransmitter concept, but they do support the notion that methane liberation may be linked to redox regulation and may be connected with hypoxic events leading to, or associated with a mitochondrial dysfunction. In this respect, the available information suggests that hypoxia-induced methane generation may be a necessary phenomenon of aerobic life, and perhaps a surviving evolutionary trait in the eukaryote cell.
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Affiliation(s)
- Mihály Boros
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szőkefalvi-Nagy B. u. 6, H-6720 Szeged, Hungary
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Abiotic methanogenesis from organosulphur compounds under ambient conditions. Nat Commun 2014; 5:4205. [PMID: 24957135 DOI: 10.1038/ncomms5205] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 05/23/2014] [Indexed: 11/08/2022] Open
Abstract
Methane in the environment is produced by both biotic and abiotic processes. Biomethanation involves the formation of methane by microbes that live in oxygen-free environments. Abiotic methane formation proceeds under conditions at elevated temperature and/or pressure. Here we present a chemical reaction that readily forms methane from organosulphur compounds under highly oxidative conditions at ambient atmospheric pressure and temperature. When using iron(II/III), hydrogen peroxide and ascorbic acid as reagents, S-methyl groups of organosulphur compounds are efficiently converted into methane. In a first step, methyl sulphides are oxidized to the corresponding sulphoxides. In the next step, demethylation of the sulphoxide via homolytic bond cleavage leads to methyl radical formation and finally to methane in high yields. Because sulphoxidation of methyl sulphides is ubiquitous in the environment, this novel chemical route might mimic methane formation in living aerobic organisms.
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Hartmann P, Fet N, Garab D, Szabó A, Kaszaki J, Srinivasan PK, Tolba RH, Boros M. L-alpha-glycerylphosphorylcholine reduces the microcirculatory dysfunction and nicotinamide adenine dinucleotide phosphate-oxidase type 4 induction after partial hepatic ischemia in rats. J Surg Res 2014; 189:32-40. [DOI: 10.1016/j.jss.2013.12.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 12/21/2013] [Accepted: 12/30/2013] [Indexed: 10/25/2022]
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Wang R. Gasotransmitters: growing pains and joys. Trends Biochem Sci 2014; 39:227-32. [PMID: 24767680 DOI: 10.1016/j.tibs.2014.03.003] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 03/24/2014] [Accepted: 03/28/2014] [Indexed: 01/19/2023]
Abstract
Gasotransmitters are endogenously generated molecules of gas. Over the past decade we have come to realize that these gaseous signaling molecules are crucially important, being irreplaceable in wide biological applications. However, there are still many challenges for future gasotransmitter research to tackle. These include clarifying the interactions among gasotransmitters; understanding the significance of the cellular gasotransmitter signaling network; and adding new members to the modern family of gasotransmitters in addition to nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S). Ammonia fulfills all criteria for being a gasotransmitter, and methane is another conceivable candidate. Following the original article postulating the concept of multiple gasotransmitters over a decade ago, this sequel article aims to further inspire interest and exploration into gasotransmitter research.
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Affiliation(s)
- Rui Wang
- Department of Biology, Cardiovascular and Metabolic Research Unit, Lakehead University, Thunder Bay, Ontario, Canada.
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Tőkés T, Tuboly E, Varga G, Major L, Ghyczy M, Kaszaki J, Boros M. Protective effects of L-alpha-glycerylphosphorylcholine on ischaemia-reperfusion-induced inflammatory reactions. Eur J Nutr 2014; 54:109-18. [PMID: 24682350 DOI: 10.1007/s00394-014-0691-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 03/20/2014] [Indexed: 02/07/2023]
Abstract
PURPOSE Choline-containing dietary phospholipids, including phosphatidylcholine (PC), may function as anti-inflammatory substances, but the mechanism remains largely unknown. We investigated the effects of L-alpha-glycerylphosphorylcholine (GPC), a deacylated PC derivative, in a rodent model of small intestinal ischaemia-reperfusion (IR) injury. METHODS Anaesthetized Sprague-Dawley rats were divided into control, mesenteric IR (45 min mesenteric artery occlusion, followed by 180 min reperfusion), IR with GPC pretreatment (16.56 mg kg⁻¹ GPC i.v., 5 min prior to ischaemia) or IR with GPC post-treatment (16.56 mg kg⁻¹ GPC i.v., 5 min prior to reperfusion) groups. Macrohaemodynamics and microhaemodynamic parameters were measured; intestinal inflammatory markers (xanthine oxidoreductase activity, superoxide and nitrotyrosine levels) and liver ATP contents were determined. RESULTS The IR challenge reduced the intestinal intramural red blood cell velocity, increased the mesenteric vascular resistance, the tissue xanthine oxidoreductase activity, the superoxide production, and the nitrotyrosine levels, and the ATP content of the liver was decreased. Exogenous GPC attenuated the macro- and microcirculatory dysfunction and provided significant protection against the radical production resulting from the IR stress. The GPC pretreatment alleviated the hepatic ATP depletion, the reductions in the mean arterial pressure and superior mesenteric artery flow, and similarly to the post-treatments with GPC, also decreased the xanthine oxidoreductase activity, the intestinal superoxide production, the nitrotyrosine level, and normalized the microcirculatory dysfunction. CONCLUSIONS These data demonstrate the effectiveness of GPC therapies and provide indirect evidence that the anti-inflammatory effects of PC could be linked to a reaction involving the polar part of the molecule.
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Affiliation(s)
- Tünde Tőkés
- Institute of Surgical Research, University of Szeged, Pécsi u. 6., Szeged, 6720, Hungary
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He Y, Sun E, Zhao Y, Hai L, Wu Y. The one-pot synthesis of 4-aryl-1H-1,2,3-triazoles without azides and metal catalization. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2013.10.125] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Tuboly E, Szabó A, Erős G, Mohácsi Á, Szabó G, Tengölics R, Rákhely G, Boros M. Determination of endogenous methane formation by photoacoustic spectroscopy. J Breath Res 2013; 7:046004. [PMID: 24185326 DOI: 10.1088/1752-7155/7/4/046004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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