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Di Mattia M, Sallese M, Neri M, Lopetuso LR. Hypoxic Functional Regulation Pathways in the GI Tract: Focus on the HIF-1α and Microbiota's Crosstalk. Inflamm Bowel Dis 2024; 30:1406-1418. [PMID: 38484200 DOI: 10.1093/ibd/izae046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Indexed: 08/02/2024]
Abstract
Hypoxia is an essential gastrointestinal (GI) tract phenomenon that influences both physiologic and pathologic states. Hypoxia-inducible factors (HIFs), the primary drivers of cell adaptation to low-oxygen environments, have been identified as critical regulators of gut homeostasis: directly, through the induction of different proteins linked to intestinal barrier stabilization (ie, adherent proteins, tight junctions, mucins, integrins, intestinal trefoil factor, and adenosine); and indirectly, through the regulation of several immune cell types and the modulation of autophagy and inflammatory processes. Furthermore, hypoxia and HIF-related sensing pathways influence the delicate relationship existing between bacteria and mammalian host cells. In turn, gut commensals establish and maintain the physiologic hypoxia of the GI tract and HIF-α expression. Based on this premise, the goals of this review are to (1) highlight hypoxic molecular pathways in the GI tract, both in physiologic and pathophysiologic settings, such as inflammatory bowel disease; and (2) discuss a potential strategy for ameliorating gut-related disorders, by targeting HIF signaling, which can alleviate inflammatory processes, restore autophagy correct mechanisms, and benefit the host-microbiota equilibrium.
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Affiliation(s)
- Miriam Di Mattia
- Department of Medicine and Ageing Sciences, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
- Center for Advanced Studies and Technology, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
| | - Michele Sallese
- Department of Medicine and Ageing Sciences, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
- Center for Advanced Studies and Technology, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
| | - Matteo Neri
- Department of Medicine and Ageing Sciences, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
- Center for Advanced Studies and Technology, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
| | - Loris Riccardo Lopetuso
- Department of Medicine and Ageing Sciences, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
- Center for Advanced Studies and Technology, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
- Medicina Interna e Gastroenterologia, CEMAD Centro Malattie dell'Apparato Digerente, Dipartimento di Scienze Mediche e Chirurgiche, Fondazione Policlinico Universitario Gemelli IRCCS, Rome, Italy
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2
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Rahane D, Dhingra T, Chalavady G, Datta A, Ghosh B, Rana N, Borah A, Saraf S, Bhattacharya P. Hypoxia and its effect on the cellular system. Cell Biochem Funct 2024; 42:e3940. [PMID: 38379257 DOI: 10.1002/cbf.3940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/08/2024] [Accepted: 01/11/2024] [Indexed: 02/22/2024]
Abstract
Eukaryotic cells utilize oxygen for different functions of cell organelles owing to cellular survival. A balanced oxygen homeostasis is an essential requirement to maintain the regulation of normal cellular systems. Any changes in the oxygen level are stressful and can alter the expression of different homeostasis regulatory genes and proteins. Lack of oxygen or hypoxia results in oxidative stress and formation of hypoxia inducible factors (HIF) and reactive oxygen species (ROS). Substantial cellular damages due to hypoxia have been reported to play a major role in various pathological conditions. There are different studies which demonstrated that the functions of cellular system are disrupted by hypoxia. Currently, study on cellular effects following hypoxia is an important field of research as it not only helps to decipher different signaling pathway modulation, but also helps to explore novel therapeutic strategies. On the basis of the beneficial effect of hypoxia preconditioning of cellular organelles, many therapeutic investigations are ongoing as a promising disease management strategy in near future. Hence, the present review discusses about the effects of hypoxia on different cellular organelles, mechanisms and their involvement in the progression of different diseases.
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Affiliation(s)
- Dipali Rahane
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat, India
| | - Tannu Dhingra
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat, India
| | - Guruswami Chalavady
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat, India
| | - Aishika Datta
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat, India
| | - Bijoyani Ghosh
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat, India
| | - Nikita Rana
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat, India
| | - Anupom Borah
- Cellular and Molecular Neurobiology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, Assam, India
| | - Shailendra Saraf
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat, India
| | - Pallab Bhattacharya
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat, India
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Doenyas-Barak K, Kutz I, Lang E, Merzbach R, Lev Wiesel R, Boussi-Gross R, Efrati S. The use of hyperbaric oxygen for veterans with PTSD: basic physiology and current available clinical data. Front Neurosci 2023; 17:1259473. [PMID: 38027524 PMCID: PMC10630921 DOI: 10.3389/fnins.2023.1259473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/09/2023] [Indexed: 12/01/2023] Open
Abstract
Post-traumatic stress disorder (PTSD) affects up to 30% of veterans returning from the combat zone. Unfortunately, a substantial proportion of them do not remit with the current available treatments and thus continue to experience long-term social, behavioral, and occupational dysfunction. Accumulating data implies that the long-standing unremitting symptoms are related to changes in brain activity and structure, mainly disruption in the frontolimbic circuit. Hence, repair of brain structure and restoration of function could be a potential aim of effective treatment. Hyperbaric oxygen therapy (HBOT) has been effective in treating disruptions of brain structure and functions such as stroke, traumatic brain injury, and fibromyalgia even years after the acute insult. These favorable HBOT brain effects may be related to recent protocols that emphasize frequent fluctuations in oxygen concentrations, which in turn contribute to gene expression alterations and metabolic changes that induce neuronal stem cell proliferation, mitochondrial multiplication, angiogenesis, and regulation of the inflammatory cascade. Recently, clinical findings have also demonstrated the beneficial effect of HBOT on veterans with treatment-resistant PTSD. Moderation of intrusive symptoms, avoidance, mood and cognitive symptoms, and hyperarousal were correlated with improved brain function and with diffusion tensor imaging-defined structural changes. This article reviews the current data on the regenerative biological effects of HBOT, and the ongoing research of its use for veterans with PTSD.
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Affiliation(s)
- Keren Doenyas-Barak
- Sagol Center for Hyperbaric Medicine and Research, Shamir Medical Center, Zerifin, Israel
- School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ilan Kutz
- Sagol Center for Hyperbaric Medicine and Research, Shamir Medical Center, Zerifin, Israel
| | - Erez Lang
- Sagol Center for Hyperbaric Medicine and Research, Shamir Medical Center, Zerifin, Israel
- School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Rachel Merzbach
- Sagol Center for Hyperbaric Medicine and Research, Shamir Medical Center, Zerifin, Israel
- The Louis and Gabi Weisfeld School of Social Work, Bar-Ilan University, Ramat Gan, Israel
| | - Rachel Lev Wiesel
- Sagol Center for Hyperbaric Medicine and Research, Shamir Medical Center, Zerifin, Israel
- The Emili Sagol Creative Arts Therapies Research Center, University of Haifa, Haifa, Israel
| | - Rahav Boussi-Gross
- Sagol Center for Hyperbaric Medicine and Research, Shamir Medical Center, Zerifin, Israel
| | - Shai Efrati
- Sagol Center for Hyperbaric Medicine and Research, Shamir Medical Center, Zerifin, Israel
- School of Medicine, Tel Aviv University, Tel Aviv, Israel
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4
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Mendonsa AA, Soeldner CC, Mudd NE, Saccomano SC, Cash KJ. Triplet-Triplet Annihilation Upconversion-Based Oxygen Sensors to Overcome the Limitation of Autofluorescence. ACS Sens 2023; 8:3043-3050. [PMID: 37540503 PMCID: PMC10566256 DOI: 10.1021/acssensors.3c00548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Autofluorescence is one of the many challenges in bioimaging as it can mask the emission from fluorescent probes or markers, a limitation that can be overcome via upconversion. Herein, we have developed a nanosensor that uses triplet-triplet annihilation upconversion to optically report changes in the dissolved oxygen concentration. Using a sensitizer-annihilator dye pairing of platinum(II) octaethylporphyrin and 9,10-diphenylanthracene, we monitored the oxygen consumption (as a proxy for metabolic activity) over time in a biological system─Saccharomyces cerevisiae (brewing yeast). The nanosensor demonstrated good reversibility over multiple cycles and showed good signal and colloidal stability when tested over the course of 7 days, and it was sensitive to dissolved oxygen from 0.00 to 3.17 mg/L O2. Additionally, there was no signal overlap between the nanosensor emission and S. cerevisiae autofluorescence, thus underscoring the utility of upconversion as a facile and economical means of overcoming autofluorescence.
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Affiliation(s)
- Adrian A. Mendonsa
- Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Cassandra C. Soeldner
- Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Natalie E. Mudd
- Quantitative Biosciences and Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Samuel C. Saccomano
- Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Kevin J. Cash
- Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
- Quantitative Biosciences and Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
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5
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Zhang Q, Inagaki NF, Ito T. Recent advances in micro-sized oxygen carriers inspired by red blood cells. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2023; 24:2223050. [PMID: 37363800 PMCID: PMC10288928 DOI: 10.1080/14686996.2023.2223050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/22/2023] [Accepted: 05/31/2023] [Indexed: 06/28/2023]
Abstract
Supplementing sufficient oxygen to cells is always challenging in biomedical engineering fields such as tissue engineering. Originating from the concept of a 'blood substitute', nano-sized artificial oxygen carriers (AOCs) have been studied for a long time for the optimization of the oxygen supplementation and improvement of hypoxia environments in vitro and in vivo. When circulating in our bodies, micro-sized human red blood cells (hRBCs) feature a high oxygen capacity, a unique biconcave shape, biomechanical and rheological properties, and low frictional surfaces, making them efficient natural oxygen carriers. Inspired by hRBCs, recent studies have focused on evolving different AOCs into microparticles more feasibly able to achieve desired architectures and morphologies and to obtain the corresponding advantages. Recent micro-sized AOCs have been developed into additional categories based on their principal oxygen-carrying or oxygen-releasing materials. Various biomaterials such as lipids, proteins, and polymers have also been used to prepare oxygen carriers owing to their rapid oxygen transfer, high oxygen capacity, excellent colloidal stability, biocompatibility, suitable biodegradability, and long storage. In this review, we concentrated on the fabrication techniques, applied biomaterials, and design considerations of micro-sized AOCs to illustrate the advances in their performances. We also compared certain recent micro-sized AOCs with hRBCs where applicable and appropriate. Furthermore, we discussed existing and potential applications of different types of micro-sized AOCs.
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Affiliation(s)
- Qiming Zhang
- Department of Chemical System Engineering, The University of Tokyo, Tokyo, Japan
| | - Natsuko F. Inagaki
- Center for Disease Biology and Integrative Medicine, The University of Tokyo, Tokyo, Japan
| | - Taichi Ito
- Department of Chemical System Engineering, The University of Tokyo, Tokyo, Japan
- Center for Disease Biology and Integrative Medicine, The University of Tokyo, Tokyo, Japan
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6
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Nikolopoulos VK, Augustine R, Camci-Unal G. Harnessing the potential of oxygen-generating materials and their utilization in organ-specific delivery of oxygen. Biomater Sci 2023; 11:1567-1588. [PMID: 36688522 PMCID: PMC10015602 DOI: 10.1039/d2bm01329k] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The limited availability of transplantable organs hinders the success of patient treatment through organ transplantation. In addition, there are challenges with immune rejection and the risk of disease transmission when receiving organs from other individuals. Tissue engineering aims to overcome these challenges by generating functional three-dimensional (3D) tissue constructs. When developing tissues or organs of a particular shape, structure, and size as determined by the specific needs of the therapeutic intervention, a tissue specific oxygen supply to all parts of the tissue construct is an utmost requirement. Moreover, the lack of a functional vasculature in engineered tissues decreases cell survival upon implantation in the body. Oxygen-generating materials can alleviate this challenge in engineered tissue constructs by providing oxygen in a sustained and controlled manner. Oxygen-generating materials can be incorporated into 3D scaffolds allowing the cells to receive and utilize oxygen efficiently. In this review, we present an overview of the use of oxygen-generating materials in various tissue engineering applications in an organ specific manner as well as their potential use in the clinic.
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Affiliation(s)
- Vasilios K Nikolopoulos
- Department of Chemical Engineering, University of Massachusetts, Lowell, Massachusetts 01854, USA.
| | - Robin Augustine
- Department of Chemical Engineering, University of Massachusetts, Lowell, Massachusetts 01854, USA.
| | - Gulden Camci-Unal
- Department of Chemical Engineering, University of Massachusetts, Lowell, Massachusetts 01854, USA.
- Department of Surgery, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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Wang YT, Trzeciak AJ, Rojas WS, Saavedra P, Chen YT, Chirayil R, Etchegaray JI, Lucas CD, Puleston DJ, Keshari KR, Perry JSA. Metabolic adaptation supports enhanced macrophage efferocytosis in limited-oxygen environments. Cell Metab 2023; 35:316-331.e6. [PMID: 36584675 PMCID: PMC9908853 DOI: 10.1016/j.cmet.2022.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/23/2022] [Accepted: 12/06/2022] [Indexed: 12/30/2022]
Abstract
Apoptotic cell (AC) clearance (efferocytosis) is performed by phagocytes, such as macrophages, that inhabit harsh physiological environments. Here, we find that macrophages display enhanced efferocytosis under prolonged (chronic) physiological hypoxia, characterized by increased internalization and accelerated degradation of ACs. Transcriptional and translational analyses revealed that chronic physiological hypoxia induces two distinct but complimentary states. The first, "primed" state, consists of concomitant transcription and translation of metabolic programs in AC-naive macrophages that persist during efferocytosis. The second, "poised" state, consists of transcription, but not translation, of phagocyte function programs in AC-naive macrophages that are translated during efferocytosis. Mechanistically, macrophages efficiently flux glucose into a noncanonical pentose phosphate pathway (PPP) loop to enhance NADPH production. PPP-derived NADPH directly supports enhanced efferocytosis under physiological hypoxia by ensuring phagolysosomal maturation and redox homeostasis. Thus, macrophages residing under physiological hypoxia adopt states that support cell fitness and ensure performance of essential homeostatic functions rapidly and safely.
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Affiliation(s)
- Ya-Ting Wang
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Alissa J Trzeciak
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Waleska Saitz Rojas
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Pedro Saavedra
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Yan-Ting Chen
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Rachel Chirayil
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jon Iker Etchegaray
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Christopher D Lucas
- University of Edinburgh Centre for Inflammation Research, Queen's Medical Research Institute, Edinburgh BioQuarter, Edinburgh, Scotland, UK; Institute for Regeneration and Repair, Edinburgh BioQuarter, Edinburgh, Scotland, UK
| | - Daniel J Puleston
- Bloomberg, Kimmel Institute of Cancer Immunotherapy, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, USA
| | - Kayvan R Keshari
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Justin S A Perry
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Immunology and Microbial Pathogenesis, Weill Cornell Medical College, New York, NY, USA.
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Endogenous glutamine is rate-limiting for anti-CD3 and anti-CD28 induced CD4+ T-cell proliferation and glycolytic activity under hypoxia and normoxia. Biochem J 2022; 479:1221-1235. [PMID: 35695514 PMCID: PMC9246347 DOI: 10.1042/bcj20220144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/09/2022] [Accepted: 05/26/2022] [Indexed: 12/29/2022]
Abstract
To meet the demand for energy and biomass, T lymphocytes (T cells) activated to proliferation and clonal expansion, require uptake and metabolism of glucose (Gluc) and the amino acid (AA) glutamine (Gln). Whereas exogenous Gln is converted to glutamate (Glu) by glutaminase (GLS), Gln is also synthesized from the endogenous pool of AA through Glu and activity of glutamine synthase (GS). Most of this knowledge comes from studies on cell cultures under ambient oxygen conditions (normoxia, 21% O2). However, in vivo, antigen induced T-cell activation often occurs under moderately hypoxic (1-4% O2) conditions and at various levels of exogenous nutrients. Here, CD4+ T cells were stimulated for 72 h with antibodies targeting the CD3 and CD28 markers at normoxia and hypoxia (1% O2). This was done in the presence and absence of the GLS and GS inhibitors, Bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl) ethyl sulfide (BPTES) and methionine sulfoximine (MSO) and at various combinations of exogenous Gluc, Gln and pyruvate (Pyr) for the last 12 h of stimulation. We found that T-cell proliferation, viability and levels of endogenous AA were significantly influenced by the availability of exogenous Gln, Gluc and Pyr as well as inhibition of GLS and GS. Moreover, inhibition of GLS and GS and levels of oxygen differentially influenced oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). Finally, BPTES-dependent down-regulation of ECAR was associated with reduced hexokinase (HK) activity at both normoxia and hypoxia. Our results demonstrate that Gln availability and metabolism is rate-limiting for CD4+ T-cell activity.
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Neonatal Oxidative Stress Impairs Cortical Synapse Formation and GABA Homeostasis in Parvalbumin-Expressing Interneurons. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:8469756. [PMID: 35663195 PMCID: PMC9159830 DOI: 10.1155/2022/8469756] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/08/2022] [Indexed: 11/28/2022]
Abstract
Neonatal brain injury is often caused by preterm birth. Brain development is vulnerable to increased environmental stress, including oxidative stress challenges. Due to a premature change of the fetal living environment from low oxygen in utero into postnatal high-oxygen room air conditions ex utero, the immature preterm brain is exposed to a relative hyperoxia, which can induce oxidative stress and impair neuronal cell development. To simulate the drastic increase of oxygen exposure in the immature brain, 5-day-old C57BL/6 mice were exposed to hyperoxia (80% oxygen) for 48 hours or kept in room air (normoxia, 21% oxygen) and mice were analyzed for maturational alterations of cortical GABAergic interneurons. As a result, oxidative stress was indicated by elevated tyrosine nitration of proteins. We found perturbation of perineuronal net formation in line with decreased density of parvalbumin-expressing (PVALB) cortical interneurons in hyperoxic mice. Moreover, maturational deficits of cortical PVALB+ interneurons were obtained by decreased glutamate decarboxylase 67 (GAD67) protein expression in Western blot analysis and lower gamma-aminobutyric acid (GABA) fluorescence intensity in immunostaining. Hyperoxia-induced oxidative stress affected cortical synaptogenesis by decreasing synapsin 1, synapsin 2, and synaptophysin expression. Developmental delay of synaptic marker expression was demonstrated together with decreased PI3K-signaling as a pathway being involved in synaptogenesis. These results elucidate that neonatal oxidative stress caused by increased oxygen exposure can lead to GABAergic interneuron damage which may serve as an explanation for the high incidence of psychiatric and behavioral alterations found in preterm infants.
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‘Big History’, history and citations in nutritional science. J Nutr Sci 2022; 11:e18. [PMID: 35320925 PMCID: PMC8922151 DOI: 10.1017/jns.2022.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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11
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Abstract
I had been working on the endocrine and signalling role of white adipose tissue (WAT) since 1994 following the identification of the ob (Lep) gene(1), this after some 15 years investigating the physiological role of brown adipose tissue. The ob gene, a mutation in which it is responsible for the profound obesity of ob/ob (Lepob/Lepob) mice, is expressed primarily in white adipocytes and encodes the pleiotropic hormone leptin. The discovery of this adipocyte hormone had wide-ranging implications, including that white fat has multiple functions that far transcend the traditional picture of a simple lipid storage organ.
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Lichtenberg M, Jakobsen TH, Kühl M, Kolpen M, Jensen PØ, Bjarnsholt T. OUP accepted manuscript. FEMS Microbiol Rev 2022; 46:6574409. [PMID: 35472245 PMCID: PMC9438473 DOI: 10.1093/femsre/fuac018] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 04/04/2022] [Accepted: 04/24/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, København, Denmark
| | - Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, København, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark
| | - Mette Kolpen
- Department of Clinical Microbiology, Copenhagen University Hospital, Ole Maaløes vej 26, 2200, København, Denmark
| | - Peter Østrup Jensen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, København, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital, Ole Maaløes vej 26, 2200, København, Denmark
| | - Thomas Bjarnsholt
- Corresponding author: Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, København, Denmark. Tel: +45 20659888; E-mail:
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Lopez-Pascual A, Trayhurn P, Martínez JA, González-Muniesa P. Oxygen in Metabolic Dysfunction and Its Therapeutic Relevance. Antioxid Redox Signal 2021; 35:642-687. [PMID: 34036800 DOI: 10.1089/ars.2019.7901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Significance: In recent years, a number of studies have shown altered oxygen partial pressure at a tissue level in metabolic disorders, and some researchers have considered oxygen to be a (macro) nutrient. Oxygen availability may be compromised in obesity and several other metabolism-related pathological conditions, including sleep apnea-hypopnea syndrome, the metabolic syndrome (which is a set of conditions), type 2 diabetes, cardiovascular disease, and cancer. Recent Advances: Strategies designed to reduce adiposity and its accompanying disorders have been mainly centered on nutritional interventions and physical activity programs. However, novel therapies are needed since these approaches have not been sufficient to counteract the worldwide increasing rates of metabolic disorders. In this regard, intermittent hypoxia training and hyperoxia could be potential treatments through oxygen-related adaptations. Moreover, living at a high altitude may have a protective effect against the development of abnormal metabolic conditions. In addition, oxygen delivery systems may be of therapeutic value for supplying the tissue-specific oxygen requirements. Critical Issues: Precise in vivo methods to measure oxygenation are vital to disentangle some of the controversies related to this research area. Further, it is evident that there is a growing need for novel in vitro models to study the potential pathways involved in metabolic dysfunction to find appropriate therapeutic targets. Future Directions: Based on the existing evidence, it is suggested that oxygen availability has a key role in obesity and its related comorbidities. Oxygen should be considered in relation to potential therapeutic strategies in the treatment and prevention of metabolic disorders. Antioxid. Redox Signal. 35, 642-687.
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Affiliation(s)
- Amaya Lopez-Pascual
- Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, Centre for Nutrition Research, University of Navarra, Pamplona, Spain.,Neuroendocrine Cell Biology, Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Paul Trayhurn
- Obesity Biology Unit, University of Liverpool, Liverpool, United Kingdom.,Clore Laboratory, The University of Buckingham, Buckingham, United Kingdom
| | - J Alfredo Martínez
- Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, Centre for Nutrition Research, University of Navarra, Pamplona, Spain.,IdiSNA, Navarra Institute for Health Research, Pamplona, Spain.,CIBERobn Physiopathology of Obesity and Nutrition, Centre of Biomedical Research Network, ISCIII, Madrid, Spain.,Precision Nutrition and Cardiometabolic Health, IMDEA Food, Madrid Institute for Advanced Studies, Madrid, Spain
| | - Pedro González-Muniesa
- Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, Centre for Nutrition Research, University of Navarra, Pamplona, Spain.,IdiSNA, Navarra Institute for Health Research, Pamplona, Spain.,CIBERobn Physiopathology of Obesity and Nutrition, Centre of Biomedical Research Network, ISCIII, Madrid, Spain
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Ortega MA, Fraile-Martinez O, García-Montero C, Callejón-Peláez E, Sáez MA, Álvarez-Mon MA, García-Honduvilla N, Monserrat J, Álvarez-Mon M, Bujan J, Canals ML. A General Overview on the Hyperbaric Oxygen Therapy: Applications, Mechanisms and Translational Opportunities. MEDICINA (KAUNAS, LITHUANIA) 2021; 57:864. [PMID: 34577787 PMCID: PMC8465921 DOI: 10.3390/medicina57090864] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/09/2021] [Accepted: 08/20/2021] [Indexed: 12/17/2022]
Abstract
Hyperbaric oxygen therapy (HBOT) consists of using of pure oxygen at increased pressure (in general, 2-3 atmospheres) leading to augmented oxygen levels in the blood (Hyperoxemia) and tissue (Hyperoxia). The increased pressure and oxygen bioavailability might be related to a plethora of applications, particularly in hypoxic regions, also exerting antimicrobial, immunomodulatory and angiogenic properties, among others. In this review, we will discuss in detail the physiological relevance of oxygen and the therapeutical basis of HBOT, collecting current indications and underlying mechanisms. Furthermore, potential areas of research will also be examined, including inflammatory and systemic maladies, COVID-19 and cancer. Finally, the adverse effects and contraindications associated with this therapy and future directions of research will be considered. Overall, we encourage further research in this field to extend the possible uses of this procedure. The inclusion of HBOT in future clinical research could be an additional support in the clinical management of multiple pathologies.
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Affiliation(s)
- Miguel A. Ortega
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
- Cancer Registry and Pathology Department, Hospital Universitario Principe de Asturias, 28806 Alcala de Henares, Spain
| | - Oscar Fraile-Martinez
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
| | - Cielo García-Montero
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
| | - Enrique Callejón-Peláez
- Underwater and Hyperbaric Medicine Service, Central University Hospital of Defence—UAH Madrid, 28801 Alcala de Henares, Spain;
| | - Miguel A. Sáez
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
- Pathological Anatomy Service, Central University Hospital of Defence—UAH Madrid, 28801 Alcala de Henares, Spain
| | - Miguel A. Álvarez-Mon
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
| | - Natalio García-Honduvilla
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
| | - Jorge Monserrat
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
| | - Melchor Álvarez-Mon
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
- Immune System Diseases—Rheumatology, Oncology Service an Internal Medicine, University Hospital Príncipe de Asturias, (CIBEREHD), 28806 Alcala de Henares, Spain
| | - Julia Bujan
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, 28801 Alcala de Henares, Spain; (C.G.-M.); (M.A.S.); (M.A.Á.-M.); (N.G.-H.); (J.M.); (M.Á.-M.); (J.B.)
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), 28034 Madrid, Spain
| | - María Luisa Canals
- ISM, IMHA Research Chair, Former of IMHA (International Maritime Health Association), 43001 Tarragona, Spain;
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Di Mattia M, Mauro A, Citeroni MR, Dufrusine B, Peserico A, Russo V, Berardinelli P, Dainese E, Cimini A, Barboni B. Insight into Hypoxia Stemness Control. Cells 2021; 10:cells10082161. [PMID: 34440930 PMCID: PMC8394199 DOI: 10.3390/cells10082161] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 01/10/2023] Open
Abstract
Recently, the research on stemness and multilineage differentiation mechanisms has greatly increased its value due to the potential therapeutic impact of stem cell-based approaches. Stem cells modulate their self-renewing and differentiation capacities in response to endogenous and/or extrinsic factors that can control stem cell fate. One key factor controlling stem cell phenotype is oxygen (O2). Several pieces of evidence demonstrated that the complexity of reproducing O2 physiological tensions and gradients in culture is responsible for defective stem cell behavior in vitro and after transplantation. This evidence is still worsened by considering that stem cells are conventionally incubated under non-physiological air O2 tension (21%). Therefore, the study of mechanisms and signaling activated at lower O2 tension, such as those existing under native microenvironments (referred to as hypoxia), represent an effective strategy to define if O2 is essential in preserving naïve stemness potential as well as in modulating their differentiation. Starting from this premise, the goal of the present review is to report the status of the art about the link existing between hypoxia and stemness providing insight into the factors/molecules involved, to design targeted strategies that, recapitulating naïve O2 signals, enable towards the therapeutic use of stem cell for tissue engineering and regenerative medicine.
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Affiliation(s)
- Miriam Di Mattia
- Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy; (M.D.M.); (M.R.C.); (A.P.); (V.R.); (P.B.); (E.D.); (B.B.)
| | - Annunziata Mauro
- Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy; (M.D.M.); (M.R.C.); (A.P.); (V.R.); (P.B.); (E.D.); (B.B.)
- Correspondence: ; Tel.: +39-086-1426-6888; Fax: +39-08-6126-6860
| | - Maria Rita Citeroni
- Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy; (M.D.M.); (M.R.C.); (A.P.); (V.R.); (P.B.); (E.D.); (B.B.)
| | - Beatrice Dufrusine
- Department of Innovative Technologies in Medicine & Dentistry, University of Chieti-Pescara, 66100 Chieti, Italy;
- Center of Advanced Studies and Technology (CAST), 66100 Chieti, Italy
| | - Alessia Peserico
- Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy; (M.D.M.); (M.R.C.); (A.P.); (V.R.); (P.B.); (E.D.); (B.B.)
| | - Valentina Russo
- Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy; (M.D.M.); (M.R.C.); (A.P.); (V.R.); (P.B.); (E.D.); (B.B.)
| | - Paolo Berardinelli
- Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy; (M.D.M.); (M.R.C.); (A.P.); (V.R.); (P.B.); (E.D.); (B.B.)
| | - Enrico Dainese
- Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy; (M.D.M.); (M.R.C.); (A.P.); (V.R.); (P.B.); (E.D.); (B.B.)
| | - Annamaria Cimini
- Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy;
- Sbarro Institute for Cancer Research and Molecular Medicine and Center for Biotechnology, Temple University, Philadelphia, PA 19122, USA
| | - Barbara Barboni
- Unit of Basic and Applied Biosciences, Faculty of Bioscience and Agro-Food and Environmental Technology, University of Teramo, 64100 Teramo, Italy; (M.D.M.); (M.R.C.); (A.P.); (V.R.); (P.B.); (E.D.); (B.B.)
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16
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Oxygen Deficient (OD) Combustion and Metabolism: Allometric Laws of Organs and Kleiber’s Law from OD Metabolism? SYSTEMS 2021. [DOI: 10.3390/systems9030054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The biology literature presents allometric relations for the specific metabolic rate (SMRk) of an organ k of mass mk within the body of mass mB: SMRk ∝ mBfk (body mass allometry, BMA). Wang et al. used BMA, summed-up energy from all organs and validated Kleiber’s law of the whole body: SMRM ∝ mBb’, b’ = −0.25. The issues raised in biology are: (i) why fk and b’ < 0, (ii) how do the organs adjust fk to yield b’? The current paper presents a “system” approach involving the field of oxygen deficient combustion (ODC) of a cloud of carbon particles and oxygen deficient metabolism (ODM), and provides partial answers by treating each vital organ as a cell cloud. The methodology yields the following: (i) a dimensionless “group” number GOD to indicate extent of ODM, (ii) SMRk of an organ in terms of the effectiveness factor; (iii) curve fitting of the effectiveness factor to yield the allometric exponents for the organ mass-based allometric laws (OMA); (iv) validation of the results with data from 111 biological species (BS) with mB ranging from 0.0075 to 6500 kg. The “hypoxic” condition at organ level, particularly for COVID-19 patients, and the onset of cancer and virus multiplication are interpreted in terms of ODM and glycolysis.
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17
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Błaszczyk JW. Energy Metabolism Decline in the Aging Brain-Pathogenesis of Neurodegenerative Disorders. Metabolites 2020; 10:metabo10110450. [PMID: 33171879 PMCID: PMC7695180 DOI: 10.3390/metabo10110450] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/31/2020] [Accepted: 11/04/2020] [Indexed: 12/14/2022] Open
Abstract
There is a growing body of evidencethat indicates that the aging of the brain results from the decline of energy metabolism. In particular, the neuronal metabolism of glucose declines steadily, resulting in a growing deficit of adenosine triphosphate (ATP) production-which, in turn, limits glucose access. This vicious circle of energy metabolism at the cellular level is evoked by a rising deficiency of nicotinamide adenine dinucleotide (NAD) in the mitochondrial salvage pathway and subsequent impairment of the Krebs cycle. A decreasing NAD level also impoverishes the activity of NAD-dependent enzymes that augments genetic errors and initiate processes of neuronal degeneration and death.This sequence of events is characteristic of several brain structures in which neurons have the highest energy metabolism. Neurons of the cerebral cortex and basal ganglia with long unmyelinated axons and these with numerous synaptic junctions are particularly prone to senescence and neurodegeneration. Unfortunately, functional deficits of neurodegeneration are initially well-compensated, therefore, clinical symptoms are recognized too late when the damages to the brain structures are already irreversible. Therefore, future treatment strategies in neurodegenerative disorders should focus on energy metabolism and compensation age-related NAD deficit in neurons. This review summarizes the complex interrelationships between metabolic processes on the systemic and cellular levels and provides directions on how to reduce the risk of neurodegeneration and protect the elderly against neurodegenerative diseases.
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Affiliation(s)
- Janusz Wiesław Błaszczyk
- Department of Human Motor Behavior, Jerzy Kukuczka Academy of Physical Education, 40-065 Katowice, Poland
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18
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Hadanny A, Efrati S. The Hyperoxic-Hypoxic Paradox. Biomolecules 2020; 10:biom10060958. [PMID: 32630465 PMCID: PMC7355982 DOI: 10.3390/biom10060958] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 12/12/2022] Open
Abstract
Effective metabolism is highly dependent on a narrow therapeutic range of oxygen. Accordingly, low levels of oxygen, or hypoxia, are one of the most powerful inducers of gene expression, metabolic changes, and regenerative processes, including angiogenesis and stimulation of stem cell proliferation, migration, and differentiation. The sensing of decreased oxygen levels (hypoxia) or increased oxygen levels (hyperoxia), occurs through specialized chemoreceptor cells and metabolic changes at the cellular level, which regulate the response. Interestingly, fluctuations in the free oxygen concentration rather than the absolute level of oxygen can be interpreted at the cellular level as a lack of oxygen. Thus, repeated intermittent hyperoxia can induce many of the mediators and cellular mechanisms that are usually induced during hypoxia. This is called the hyperoxic-hypoxic paradox (HHP). This article reviews oxygen physiology, the main cellular processes triggered by hypoxia, and the cascade of events triggered by the HHP.
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Affiliation(s)
- Amir Hadanny
- The Sagol Center for Hyperbaric Medicine and Research, Shamir (Assaf-Harofeh) Medical Center, Zerifin 70300, Israel;
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 6997801, Israel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
- Correspondence: ; Tel.: +972-544707381; Fax: +972-8-9779748
| | - Shai Efrati
- The Sagol Center for Hyperbaric Medicine and Research, Shamir (Assaf-Harofeh) Medical Center, Zerifin 70300, Israel;
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 6997801, Israel
- The Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv 6997801, Israel
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19
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Hadanny A, Efrati S. The Hyperoxic-Hypoxic Paradox. Biomolecules 2020; 10:biom10060958. [PMID: 32630465 DOI: 10.3390/biom1006095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 05/21/2023] Open
Abstract
Effective metabolism is highly dependent on a narrow therapeutic range of oxygen. Accordingly, low levels of oxygen, or hypoxia, are one of the most powerful inducers of gene expression, metabolic changes, and regenerative processes, including angiogenesis and stimulation of stem cell proliferation, migration, and differentiation. The sensing of decreased oxygen levels (hypoxia) or increased oxygen levels (hyperoxia), occurs through specialized chemoreceptor cells and metabolic changes at the cellular level, which regulate the response. Interestingly, fluctuations in the free oxygen concentration rather than the absolute level of oxygen can be interpreted at the cellular level as a lack of oxygen. Thus, repeated intermittent hyperoxia can induce many of the mediators and cellular mechanisms that are usually induced during hypoxia. This is called the hyperoxic-hypoxic paradox (HHP). This article reviews oxygen physiology, the main cellular processes triggered by hypoxia, and the cascade of events triggered by the HHP.
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Affiliation(s)
- Amir Hadanny
- The Sagol Center for Hyperbaric Medicine and Research, Shamir (Assaf-Harofeh) Medical Center, Zerifin 70300, Israel
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 6997801, Israel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Shai Efrati
- The Sagol Center for Hyperbaric Medicine and Research, Shamir (Assaf-Harofeh) Medical Center, Zerifin 70300, Israel
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 6997801, Israel
- The Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv 6997801, Israel
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Abstract
The paper is based on the lecture that I gave on receiving the Nutrition Society's inaugural Gowland Hopkins Award for contributions to Cellular and Molecular Nutrition. It reviews studies on the adipose tissues, brown and white, conducted by the groups that I have led since entering nutrition research in 1975. The initial focus was on exploring metabolic factors that underpin the development of obesity using animal models. This resulted in an interest in non-shivering thermogenesis with brown adipose tissue being identified as the key effector of facultative heat production. Brown fat is less thermogenically active in various obese rodents, and major changes in activity are exhibited under physiological conditions such as lactation and fasting consistent with a general role for the tissue in nutritional energetics. My interests moved to white adipose tissue following the cloning of the Ob gene. Our initial contributions in this area included demonstrating nutritional regulation of Ob gene expression and circulating leptin levels, as well as a regulatory role for the sympathetic nervous system operating through β3-adrenoceptors. My interests subsequently evolved to a wider concern with the endocrine/signalling role of adipose tissue. Inflammation is a characteristic of white fat in obesity with the release of inflammation-related adipokines, and we proposed that hypoxia underlies this inflammatory state. O2-deprivation was shown to have substantial effects on gene expression and cellular function in white adipocytes. The hypoxia studies led to the proposition that O2 should be considered as a critical macronutrient.
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