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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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Huang X, Shabala L, Zhang X, Zhou M, Voesenek LACJ, Hartman S, Yu M, Shabala S. Cation transporters in cell fate determination and plant adaptive responses to a low-oxygen environment. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:636-645. [PMID: 34718542 DOI: 10.1093/jxb/erab480] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Soil flooding creates low-oxygen environments in root zones and thus severely affects plant growth and productivity. Plants adapt to low-oxygen environments by a suite of orchestrated metabolic and anatomical alterations. Of these, formation of aerenchyma and development of adventitious roots are considered very critical to enable plant performance in waterlogged soils. Both traits have been firmly associated with stress-induced increases in ethylene levels in root tissues that operate upstream of signalling pathways. Recently, we used a bioinformatic approach to demonstrate that several Ca2+ and K+ -permeable channels from KCO, AKT, and TPC families could also operate in low oxygen sensing in Arabidopsis. Here we argue that low-oxygen-induced changes to cellular ion homeostasis and operation of membrane transporters may be critical for cell fate determination and formation of the lysigenous aerenchyma in plant roots and shaping the root architecture and adventitious root development in grasses. We summarize the existing evidence for a causal link between tissue-specific changes in oxygen concentration, intracellular Ca2+ and K+ homeostasis, and reactive oxygen species levels, and their role in conferring those two major traits enabling plant adaptation to a low-oxygen environment. We conclude that, for efficient operation, plants may rely on several complementary signalling pathway mechanisms that operate in concert and 'fine-tune' each other. A better understanding of this interaction may create additional and previously unexplored opportunities to crop breeders to improve cereal crop yield losses to soil flooding.
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Affiliation(s)
- Xin Huang
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528041, China
| | - Lana Shabala
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tas 7001, Australia
| | - Xuechen Zhang
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tas 7001, Australia
| | - Meixue Zhou
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tas 7001, Australia
| | | | - Sjon Hartman
- Plant Ecophysiology, Utrecht University, 3584 CH Utrecht, The Netherlands
- School of Biosciences, University of Birmingham, Edgbaston B15 2TT, UK
| | - Min Yu
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528041, China
| | - Sergey Shabala
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528041, China
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tas 7001, Australia
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3
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Abstract
The carotid body (CB) is a bilateral arterial chemoreceptor located in the carotid artery bifurcation with an essential role in cardiorespiratory homeostasis. It is composed of highly perfused cell clusters, or glomeruli, innervated by sensory fibers. Glomus cells, the most abundant in each glomerulus, are neuron-like multimodal sensory elements able to detect and integrate changes in several physical and chemical parameters of the blood, in particular O2 tension, CO2 and pH, as well as glucose, lactate, or blood flow. Activation of glomus cells (e.g., during hypoxia or hypercapnia) stimulates the afferent fibers which impinge on brainstem neurons to elicit rapid compensatory responses (hyperventilation and sympathetic activation). This chapter presents an updated view of the structural organization of the CB and the mechanisms underlying the chemosensory responses of glomus cells, with special emphasis on the molecular processes responsible for acute O2 sensing. The properties of the glomus cell-sensory fiber synapse as well as the organization of CB output are discussed. The chapter includes the description of recently discovered CB stem cells and progenitor cells, and their role in CB growth during acclimatization to hypoxemia. Finally, the participation of the CB in the mechanisms of disease is briefly discussed.
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Affiliation(s)
- José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Sevilla, Seville, Spain; Biomedical Research Center for Neurodegenerative Diseases (CIBERNED), Madrid, Spain.
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4
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Abstract
Oxygen (O2) is essential for life and therefore the supply of sufficient O2 to the tissues is a major physiological challenge. In mammals, a deficit of O2 (hypoxia) triggers rapid cardiorespiratory reflexes (e.g. hyperventilation and increased heart output) that within a few seconds increase the uptake of O2 by the lungs and its distribution throughout the body. The prototypical acute O2-sensing organ is the carotid body (CB), which contains sensory glomus cells expressing O2-regulated ion channels. In response to hypoxia, glomus cells depolarize and release transmitters which activate afferent fibers terminating at the brainstem respiratory and autonomic centers. In this review, we summarize the basic properties of CB chemoreceptor cells and the essential role played by their specialized mitochondria in acute O2 sensing and signaling. We focus on recent data supporting a "mitochondria-to-membrane signaling" model of CB chemosensory transduction. The possibility that the differential expression of specific subunit isoforms and enzymes could allow mitochondria to play a generalized adaptive O2-sensing and signaling role in a wide variety of cells is also discussed.
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Affiliation(s)
- José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Patricia Ortega-Sáenz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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5
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Abstract
The review describes molecular mechanisms for sensing oxygen levels in various compartments of animal cell. Several pathways for intracellular oxygen sensing are discussed together with details of functioning of the near-membrane and cytoplasmic pools of molecular components in hypoxic cells. The data on the role of mitochondria in cell sensitivity to a decreased oxygen content are presented. Details of mutual influence of the operational and chronic intracellular mechanisms for detecting the negative gradients of molecular oxygen concentration and their relationship with cell metabolism response to the oxidative stress are discussed.
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Affiliation(s)
- A N Vjotosh
- Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg, 194223, Russia. .,Lesgaft National State University of Physical Education, Sport and Health, St. Petersburg, 190121, Russia.,Mechnikov North-Western State Medical University, St. Petersburg, 195067, Russia
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6
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Abstract
The carotid body (CB) is an arterial chemoreceptor organ located in the carotid bifurcation and has a well-recognized role in cardiorespiratory regulation. The CB contains neurosecretory sensory cells (glomus cells), which release transmitters in response to hypoxia, hypercapnia, and acidemia to activate afferent sensory fibers terminating in the respiratory and autonomic brainstem centers. Knowledge of the physiology of the CB has progressed enormously in recent years. Herein we review advances concerning the organization and function of the cellular elements of the CB, with emphasis on the molecular mechanisms of acute oxygen sensing by glomus cells. We introduce the modern view of the CB as a multimodal integrated metabolic sensor and describe the properties of the CB stem cell niche, which support CB growth during acclimatization to chronic hypoxia. Finally, we discuss the increasing medical relevance of CB dysfunction and its potential impact on the mechanisms of disease.
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Affiliation(s)
- Patricia Ortega-Sáenz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla 41013, Spain; , .,Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sevilla 41013, Spain
| | - José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla 41013, Spain; , .,Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sevilla 41013, Spain
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7
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da Silva MP, Moraes DJA, Bonagamba LGH, Mecawi ADS, Varanda WA, Machado BH. Hyperexcitability and plasticity induced by sustained hypoxia on rectus abdominis motoneurons. J Physiol 2019; 597:1935-1956. [PMID: 30747446 DOI: 10.1113/jp277030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 02/06/2019] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Acute hypoxia induces active expiration in rectus abdominis (RA) muscles in conscious freely moving rats, although its overall contribution is smaller than in internal oblique (IO) muscles. Tonically active and silent RA motoneurons were identified in in vitro preparations of rat spinal cords. Sustained hypoxia (SH) increased the synaptic strength and induced morphological changes in tonically active RA motoneurons. Expiratory RA motoneurons were recorded in the in situ preparation and SH enhanced both the excitability and the synaptic transmission in those firing during the stage 2 expiration. The present study contributes to a better understanding of the mechanisms involved in SH recruitment of RA motoneurons to induce active expiration in rats. ABSTRACT Rectus abdominis (RA) motoneurons translate the complex respiratory brainstem inputs into effective muscle contractions. Despite their fundamental role in respiration, their functional and morphological properties are not fully understood. In the present study, we investigated for the first time the contribution of RA muscle to active expiration and characterized RA motoneurons regarding their electrical, molecular and morphological profiles in control rats and in rats submitted to sustained hypoxia (SH), which induces chronic recruitment of abdominal muscles. Electromyographic experiments in conscious freely moving control rats and SH rats showed that RA contributes to active expiration induced by acute hypoxia, although its contribution is smaller than in internal oblique muscles. in vitro whole-cell patch clamp recordings from RA motoneurons revealed two populations of cells: tonically active and silent. SH induced hyperexcitability in the tonically active cells by changing their action potential properties, and EPSCs. Three-dimensional morphological reconstructions of these cells showed that SH increased the dendritic complexity, stimulated the appearance of dendrite spines, and increased the somatic area and volume. Physiologically identified RA motoneurons, firing in two distinct phases of expiration, were recorded in the brainstem-spinal cord in situ preparation of rats. SH increased the firing frequency and EPSCs of neurons firing during stage 2 expiration. Taken together, our results show that RA motoneurons reconfigure their biophysical properties, morphology and synaptic strength to produce an appropriate expiratory drive in response to SH in rats.
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Affiliation(s)
- Melina P da Silva
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Davi José A Moraes
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Leni G H Bonagamba
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - André de Souza Mecawi
- Paulista School of Medicine, Department of Biophysics, Federal University of São Paulo, São Paulo, Brazil
| | - Wamberto A Varanda
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Benedito H Machado
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
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8
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Abstract
Gaseous oxygen is essential for all aerobic animals, without which mitochondrial respiration and oxidative phosphorylation cannot take place. It is not, however, regarded as a "nutrient" by nutritionists and does not feature as such within the discipline of nutritional science. This is primarily a consequence of the route by which O2 enters the body, which is via the nose and lungs in terrestrial animals as opposed to the mouth and gastrointestinal tract for what are customarily considered as nutrients. It is argued that the route of entry should not be the critical factor in defining whether a substance is, or is not, a nutrient. Indeed, O2 unambiguously meets the standard dictionary definitions of a nutrient, such as "a substance that provides nourishment for the maintenance of life and for growth" (Oxford English Dictionary). O2 is generally available in abundance, but deficiency occurs at high altitude and during deep sea dives, as well as in lung diseases. These impact on the provision at a whole-body level, but a low pO2 is characteristic of specific tissues includings the retina and brain, while deficiency, or overt hypoxia, is evident in certain conditions such as ischaemic disease and in tumours - and in white adipose tissue in obesity. Hypoxia results in a switch from oxidative metabolism to increased glucose utilisation through anaerobic glycolysis, and there are extensive changes in the expression of multiple genes in O2-deficient cells. These changes are driven by hypoxia-sensitive transcription factors, particularly hypoxia-inducible factor-1 (HIF-1). O2 deficiency at a whole-body level can be treated by therapy or supplementation, but O2 is also toxic through the generation of reactive oxygen species. It is concluded that O2 is a critical, but overlooked, nutrient which should be considered as part of the landscape of nutritional science.
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Affiliation(s)
- Paul Trayhurn
- Clore Laboratory, University of Buckingham, Buckingham, United Kingdom.,Obesity Biology Unit, University of Liverpool, Liverpool, United Kingdom
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9
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Gao L, Ortega-Sáenz P, López-Barneo J. Acute oxygen sensing-Role of metabolic specifications in peripheral chemoreceptor cells. Respir Physiol Neurobiol 2018; 265:100-111. [PMID: 30172779 DOI: 10.1016/j.resp.2018.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/17/2018] [Accepted: 08/29/2018] [Indexed: 12/30/2022]
Abstract
Acute oxygen sensing is essential for humans under hypoxic environments or pathologic conditions. This is achieved by the carotid body (CB), the key arterial chemoreceptor, along with other peripheral chemoreceptor organs, such as the adrenal medulla (AM). Although it is widely accepted that inhibition of K+ channels in the plasma membrane of CB cells during acute hypoxia results in the activation of cardiorespiratory reflexes, the molecular mechanisms by which the hypoxic signal is detected to modulate ion channel activity are not fully understood. Using conditional knockout mice lacking mitochondrial complex I (MCI) subunit NDUFS2, we have found that MCI generates reactive oxygen species and pyridine nucleotides, which signal K+ channels during acute hypoxia. Comparing the transcriptomes from CB and AM, which are O2-sensitive, with superior cervical ganglion, which is practically O2-insensitive, we have found that CB and AM contain unique metabolic gene expression profiles. The "signature metabolic profile" and their biophysical characteristics could be essential for acute O2 sensing by chemoreceptor cells.
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Affiliation(s)
- Lin Gao
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
| | - Patricia Ortega-Sáenz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
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10
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Ortega-Sáenz P, Caballero C, Gao L, López-Barneo J. Testing Acute Oxygen Sensing in Genetically Modified Mice: Plethysmography and Amperometry. Methods Mol Biol 2018; 1742:139-153. [PMID: 29330797 DOI: 10.1007/978-1-4939-7665-2_13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Monitoring responsiveness to acute hypoxia of whole animals and single cells is essential to investigate the nature of the mechanisms underlying oxygen (O2) sensing. Here we describe the protocols followed in our laboratory to evaluate the ventilatory response to hypoxia in normal and genetically modified animals. We also describe the amperometric technique used to monitor single-cell catecholamine release from chemoreceptor cells in carotid body and adrenal medulla slices.
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Affiliation(s)
- Patricia Ortega-Sáenz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
| | - Candela Caballero
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Lin Gao
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.
- Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain.
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
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11
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Abstract
O2 is essential for the maintenance and growth of aerobic animals, similar to the essentiality of what are classically considered nutrients. Nevertheless, O2 is not customarily regarded as a nutrient, this reflecting the route by which it enters the body - through the lungs or gills in vertebrates, rather than via the mouth and gastrointestinal tract. A relative deficiency of O2 occurs at high altitudes and during deep-sea diving, to which distinct adaptations occur. Deficiency is also evident in lung diseases such as emphysema. Without O2, mitochondrial respiration and oxidative phosphorylation cannot take place. At a molecular level, cells adapt to O2 deficiency by switching from oxidative metabolism to anaerobic glycolysis and there are changes in the expression of a multiplicity of genes, driven by hypoxia-sensitive transcription factors, particularly hypoxia-inducible factor-1. It is argued that O2 should be fully included within the remit of nutritional science alongside the other essential macronutrients.
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12
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Minhas G, Mathur D, Ragavendrasamy B, Sharma NK, Paanu V, Anand A. Hypoxia in CNS Pathologies: Emerging Role of miRNA-Based Neurotherapeutics and Yoga Based Alternative Therapies. Front Neurosci 2017; 11:386. [PMID: 28744190 PMCID: PMC5504619 DOI: 10.3389/fnins.2017.00386] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 06/20/2017] [Indexed: 12/14/2022] Open
Abstract
Cellular respiration is a vital process for the existence of life. Any condition that results in deprivation of oxygen (also termed as hypoxia) may eventually lead to deleterious effects on the functioning of tissues. Brain being the highest consumer of oxygen is prone to increased risk of hypoxia-induced neurological insults. This in turn has been associated with many diseases of central nervous system (CNS) such as stroke, Alzheimer's, encephalopathy etc. Although several studies have investigated the pathophysiological mechanisms underlying ischemic/hypoxic CNS diseases, the knowledge about protective therapeutic strategies to ameliorate the affected neuronal cells is meager. This has augmented the need to improve our understanding of the hypoxic and ischemic events occurring in the brain and identify novel and alternate treatment modalities for such insults. MicroRNA (miRNAs), small non-coding RNA molecules, have recently emerged as potential neuroprotective agents as well as targets, under hypoxic conditions. These 18-22 nucleotide long RNA molecules are profusely present in brain and other organs and function as gene regulators by cleaving and silencing the gene expression. In brain, these are known to be involved in neuronal differentiation and plasticity. Therefore, targeting miRNA expression represents a novel therapeutic approach to intercede against hypoxic and ischemic brain injury. In the first part of this review, we will discuss the neurophysiological changes caused as a result of hypoxia, followed by the contribution of hypoxia in the neurodegenerative diseases. Secondly, we will provide recent updates and insights into the roles of miRNA in the regulation of genes in oxygen and glucose deprived brain in association with circadian rhythms and how these can be targeted as neuroprotective agents for CNS injuries. Finally, we will emphasize on alternate breathing or yogic interventions to overcome the hypoxia associated anomalies that could ultimately lead to improvement in cerebral perfusion.
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Affiliation(s)
- Gillipsie Minhas
- Neuroscience Research Lab, Department of Neurology, Post Graduate Institute of Medical Education and ResearchChandigarh, India
| | - Deepali Mathur
- Faculty of Biological Sciences, University of ValenciaValencia, Spain
| | | | - Neel K. Sharma
- Armed Forces Radiobiology Research InstituteBethesda, MD, United States
| | - Viraaj Paanu
- Government Medical College and HospitalChandigarh, India
| | - Akshay Anand
- Neuroscience Research Lab, Department of Neurology, Post Graduate Institute of Medical Education and ResearchChandigarh, India
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13
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Wang F, Chen ZH, Shabala S. Hypoxia Sensing in Plants: On a Quest for Ion Channels as Putative Oxygen Sensors. PLANT & CELL PHYSIOLOGY 2017; 58:1126-1142. [PMID: 28838128 DOI: 10.1093/pcp/pcx079] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 05/22/2017] [Indexed: 05/18/2023]
Abstract
Over 17 million km2 of land is affected by soil flooding every year, resulting in substantial yield losses and jeopardizing food security across the globe. A key step in resolving this problem and creating stress-tolerant cultivars is an understanding of the mechanisms by which plants sense low-oxygen stress. In this work, we review the current knowledge about the oxygen-sensing and signaling pathway in mammalian and plant systems and postulate the potential role of ion channels as putative oxygen sensors in plant roots. We first discuss the definition and requirements for the oxygen sensor and the difference between sensing and signaling. We then summarize the literature and identify several known candidates for oxygen sensing in the mammalian literature. This includes transient receptor potential (TRP) channels; K+-permeable channels (Kv, BK and TASK); Ca2+ channels (RyR and TPC); and various chemo- and reactive oxygen species (ROS)-dependent oxygen sensors. Identified key oxygen-sensing domains (PAS, GCS, GAF and PHD) in mammalian systems are used to predict the potential plant counterparts in Arabidopsis. Finally, the sequences of known mammalian ion channels with reported roles in oxygen sensing were employed to BLAST the Arabidopsis genome for the candidate genes. Several plasma membrane and tonoplast ion channels (such as TPC, AKT and KCO) and oxygen domain-containing proteins with predicted oxygen-sensing ability were identified and discussed. We propose a testable model for potential roles of ion channels in plant hypoxia sensing.
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Affiliation(s)
- Feifei Wang
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Zhong-Hua Chen
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia
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14
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Wang N, Kang HS, Ahmmed G, Khan SA, Makarenko VV, Prabhakar NR, Nanduri J. Calpain activation by ROS mediates human ether-a-go-go-related gene protein degradation by intermittent hypoxia. Am J Physiol Cell Physiol 2016; 310:C329-36. [PMID: 26659724 PMCID: PMC4865081 DOI: 10.1152/ajpcell.00231.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 12/04/2015] [Indexed: 11/22/2022]
Abstract
Human ether-a-go-go-related gene (hERG) channels conduct delayed rectifier K(+) current. However, little information is available on physiological situations affecting hERG channel protein and function. In the present study we examined the effects of intermittent hypoxia (IH), which is a hallmark manifestation of sleep apnea, on hERG channel protein and function. Experiments were performed on SH-SY5Y neuroblastoma cells, which express hERG protein. Cells were exposed to IH consisting of alternating cycles of 30 s of hypoxia (1.5% O2) and 5 min of 20% O2. IH decreased hERG protein expression in a stimulus-dependent manner. A similar reduction in hERG protein was also seen in adrenal medullary chromaffin cells from IH-exposed neonatal rats. The decreased hERG protein was associated with attenuated hERG K(+) current. IH-evoked hERG protein degradation was not due to reduced transcription or increased proteosome/lysomal degradation. Rather it was mediated by calcium-activated calpain proteases. Both COOH- and NH2-terminal sequences of the hERG protein were the targets of calpain-dependent degradation. IH increased reactive oxygen species (ROS) levels, intracellular Ca(2+) concentration ([Ca(2+)]i), calpain enzyme activity, and hERG protein degradation, and all these effects were prevented by manganese-(111)-tetrakis-(1-methyl-4-pyridyl)-porphyrin pentachloride, a membrane-permeable ROS scavenger. These results demonstrate that activation of calpains by ROS-dependent elevation of [Ca(2+)]i mediates hERG protein degradation by IH.
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Affiliation(s)
- N Wang
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, Illinois
| | - H S Kang
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, Illinois
| | - G Ahmmed
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, Illinois
| | - S A Khan
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, Illinois
| | - V V Makarenko
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, Illinois
| | - N R Prabhakar
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, Illinois
| | - J Nanduri
- Institute for Integrative Physiology, Biological Sciences Division, University of Chicago, Chicago, Illinois
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15
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Oxygen-sensing by arterial chemoreceptors: Mechanisms and medical translation. Mol Aspects Med 2016; 47-48:90-108. [DOI: 10.1016/j.mam.2015.12.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/01/2015] [Indexed: 12/30/2022]
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16
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Fernández-Agüera MC, Gao L, González-Rodríguez P, Pintado CO, Arias-Mayenco I, García-Flores P, García-Pergañeda A, Pascual A, Ortega-Sáenz P, López-Barneo J. Oxygen Sensing by Arterial Chemoreceptors Depends on Mitochondrial Complex I Signaling. Cell Metab 2015; 22:825-37. [PMID: 26437605 DOI: 10.1016/j.cmet.2015.09.004] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 07/17/2015] [Accepted: 09/08/2015] [Indexed: 12/30/2022]
Abstract
O2 sensing is essential for mammalian homeostasis. Peripheral chemoreceptors such as the carotid body (CB) contain cells with O2-sensitive K(+) channels, which are inhibited by hypoxia to trigger fast adaptive cardiorespiratory reflexes. How variations of O2 tension (PO2) are detected and the mechanisms whereby these changes are conveyed to membrane ion channels have remained elusive. We have studied acute O2 sensing in conditional knockout mice lacking mitochondrial complex I (MCI) genes. We inactivated Ndufs2, which encodes a protein that participates in ubiquinone binding. Ndufs2-null mice lose the hyperventilatory response to hypoxia, although they respond to hypercapnia. Ndufs2-deficient CB cells have normal functions and ATP content but are insensitive to changes in PO2. Our data suggest that chemoreceptor cells have a specialized succinate-dependent metabolism that induces an MCI state during hypoxia, characterized by the production of reactive oxygen species and accumulation of reduced pyridine nucleotides, which signal neighboring K(+) channels.
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Affiliation(s)
- M Carmen Fernández-Agüera
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Avenida Sánchez Pizjuan, 4, 41009 Seville, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain
| | - Lin Gao
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Avenida Sánchez Pizjuan, 4, 41009 Seville, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain
| | - Patricia González-Rodríguez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Avenida Sánchez Pizjuan, 4, 41009 Seville, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain
| | - C Oscar Pintado
- Centro de Producción y Experimentación Animal, Universidad de Sevilla, Calle San Fernando, 4, 41004 Seville, Spain
| | - Ignacio Arias-Mayenco
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Avenida Sánchez Pizjuan, 4, 41009 Seville, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain
| | - Paula García-Flores
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain
| | - Antonio García-Pergañeda
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain
| | - Alberto Pascual
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain
| | - Patricia Ortega-Sáenz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Avenida Sánchez Pizjuan, 4, 41009 Seville, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain
| | - José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain; Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Avenida Sánchez Pizjuan, 4, 41009 Seville, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Campus Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot, s/n, 41013 Seville, Spain.
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Abstract
Hypoxia inducible factors (HIFs) are α/β heterodimeric transcription factors that direct multiple cellular and systemic responses in response to changes in oxygen availability. The oxygen sensitive signal is generated by a series of iron and 2-oxoglutarate-dependent dioxygenases that catalyze post-translational hydroxylation of specific prolyl and asparaginyl residues in HIFα subunits and thereby promote their destruction and inactivation in the presence of oxygen. In hypoxia, these processes are suppressed allowing HIF to activate a massive transcriptional cascade. Elucidation of these pathways has opened several new fields of cardiovascular research. Here, we review the role of HIF hydroxylase pathways in cardiac development and in cardiovascular control. We also consider the current status, opportunities, and challenges of therapeutic modulation of HIF hydroxylases in the therapy of cardiovascular disease.
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Affiliation(s)
- Tammie Bishop
- From the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Peter J Ratcliffe
- From the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.
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Gamper N, Ooi L. Redox and nitric oxide-mediated regulation of sensory neuron ion channel function. Antioxid Redox Signal 2015; 22:486-504. [PMID: 24735331 PMCID: PMC4323017 DOI: 10.1089/ars.2014.5884] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
SIGNIFICANCE Reactive oxygen and nitrogen species (ROS and RNS, respectively) can intimately control neuronal excitability and synaptic strength by regulating the function of many ion channels. In peripheral sensory neurons, such regulation contributes towards the control of somatosensory processing; therefore, understanding the mechanisms of such regulation is necessary for the development of new therapeutic strategies and for the treatment of sensory dysfunctions, such as chronic pain. RECENT ADVANCES Tremendous progress in deciphering nitric oxide (NO) and ROS signaling in the nervous system has been made in recent decades. This includes the recognition of these molecules as important second messengers and the elucidation of their metabolic pathways and cellular targets. Mounting evidence suggests that these targets include many ion channels which can be directly or indirectly modulated by ROS and NO. However, the mechanisms specific to sensory neurons are still poorly understood. This review will therefore summarize recent findings that highlight the complex nature of the signaling pathways involved in redox/NO regulation of sensory neuron ion channels and excitability; references to redox mechanisms described in other neuron types will be made where necessary. CRITICAL ISSUES The complexity and interplay within the redox, NO, and other gasotransmitter modulation of protein function are still largely unresolved. Issues of specificity and intracellular localization of these signaling cascades will also be addressed. FUTURE DIRECTIONS Since our understanding of ROS and RNS signaling in sensory neurons is limited, there is a multitude of future directions; one of the most important issues for further study is the establishment of the exact roles that these signaling pathways play in pain processing and the translation of this understanding into new therapeutics.
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Affiliation(s)
- Nikita Gamper
- 1 Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds , Leeds, United Kingdom
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19
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Prabhakar NR, Peers C. Gasotransmitter regulation of ion channels: a key step in O2 sensing by the carotid body. Physiology (Bethesda) 2014; 29:49-57. [PMID: 24382871 PMCID: PMC3929115 DOI: 10.1152/physiol.00034.2013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Carotid bodies detect hypoxia in arterial blood, translating this stimulus into physiological responses via the CNS. It is long established that ion channels are critical to this process. More recent evidence indicates that gasotransmitters exert powerful influences on O2 sensing by the carotid body. Here, we review current understanding of hypoxia-dependent production of gasotransmitters, how they regulate ion channels in the carotid body, and how this impacts carotid body function.
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Affiliation(s)
- Nanduri R Prabhakar
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, Biological Sciences Division, University of Chicago, Chicago, Illinois; and
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20
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Abstract
Hypoxia develops in white adipose tissue in obese mice, resulting in changes in adipocyte function that may underpin the dysregulation that leads to obesity-associated disorders. Whether hypoxia occurs in adipose tissue in human obesity is unclear, with recent studies contradicting earlier reports that this was the case. Adipocytes, both murine and human, exhibit extensive functional changes in culture in response to hypoxia, which alters the expression of up to 1,300 genes. These include genes encoding key adipokines such as leptin, interleukin (IL)-6, vascular endothelial growth factor (VEGF), and matrix metalloproteinase-2 (MMP-2), which are upregulated, and adiponectin, which is downregulated. Hypoxia also inhibits the expression of genes linked to oxidative metabolism while stimulating the expression of genes associated with glycolysis. Glucose uptake and lactate release by adipocytes are both stimulated by hypoxia, and insulin sensitivity falls. Preadipocytes and macrophages in adipose tissue also respond to hypoxia. The hypoxia-signaling pathway may provide a new target for the treatment of obesity-associated disorders.
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Affiliation(s)
- Paul Trayhurn
- Obesity Biology Research Unit, Institute of Ageing and Chronic Diseases, University of Liverpool, Liverpool L69 3GA United Kingdom, and Clore Laboratory, University of Buckingham, Buckingham MK18 1EG, United Kingdom;
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21
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Abstract
SIGNIFICANCE Ventilatory responses to hypoxia are initiated by the carotid body, where inhibition of specific K(+) channels causes cell depolarization, voltage-gated Ca(2+) influx, and neurotransmitter release. The identity of the upstream oxygen (O2) sensor is still controversial. RECENT ADVANCES The activity of BKCa channels is regulated by O2, carbon monoxide (CO), and hydrogen sulfide (H2S), suggesting that integration of these signals may be crucial to the physiological response of this tissue. BKCa is colocalized with hemeoxygenase-2, an enzyme that generates CO in the presence of O2, and CO is a BKCa channel opener. Reduced CO during hypoxia results in channel closure, conferring a degree of O2 sensitivity to the BKCa channel. Conversely, H2S is a potent BKCa inhibitor. H2S is produced endogenously by cystathionine-β-synthase and cystathionine-γ-lyase in the rat carotid body, and its intracellular concentration is dependent upon the balance between its enzymatic generation and its mitochondrial breakdown. During hypoxia, mitochondrial oxidation of H2S in many tissues is reduced, leading to hypoxia-evoked rises in its concentration. This may be sufficient to inhibit K(+) channels and lead to carotid body excitation. CRITICAL ISSUES Carotid body function is heavily dependent upon regulated production and breakdown of CO and H2S and integration of signals from these newly emerging gasotransmitters, in combination with several other proposed mechanisms, may refine, or even define, responses of this tissue to hypoxia. FUTURE DIRECTIONS Since several other sensors have been postulated, the challenge of future research is to begin to integrate each in a unifying mechanism, as has been attempted for the first time herein.
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Affiliation(s)
- Paul J Kemp
- Division of Pathophysiology and Repair, School of Biosciences, Cardiff University , Cardiff, United Kingdom
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22
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Goswami SK, Das DK. Oxygen Sensing, Cardiac Ischemia, HIF-1α and Some Emerging Concepts. Curr Cardiol Rev 2011; 6:265-73. [PMID: 22043202 PMCID: PMC3083807 DOI: 10.2174/157340310793566136] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 09/03/2010] [Accepted: 09/15/2010] [Indexed: 11/22/2022] Open
Abstract
Oxygen plays a critical role in the perpetuation and propagation of almost all forms of life. The primary site of cellular oxygen consumption is the mitochondrial electron transport chain and in addition, oxygen is also used as a substrate for various enzymes involved in cellular homeostasis. Although our knowledge of the biochemistry and physiology of oxygen transport is century old, recent development of sophisticated tools of biophysical chemistry revealed that tissue oxygenation and oxygen sensing is a highly evolved process, especially in mammals. Perturbation of normal oxygen supply is associated with diseases like tumorigenesis, myocardial infarction and stroke. Available information suggests that when tissue oxygen supply is limited, mitochondria emanate signals involving reactive oxygen species generation which in turn stabilizes oxygen sensing transcription factor HIF-1. Upon stabilization, HIF-1 elicits necessary genetic response to cope with the diminished oxygen level. In view of such critical role of HIF-1 in cellular oxygen sensing, recently there has been a heightened interest in understanding the biology of HIF-1 in the context of cardiovascular system. The following review describes some of the recent advances in this regard.
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Affiliation(s)
- Shyamal K Goswami
- Cardiovascular Research Center, University of Connecticut School of Medicine, Farmington, Connecticut, CT 06030- 1110, USA
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23
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Peers C, Dallas ML, Scragg JL. Ion channels as effectors in carbon monoxide signaling. Commun Integr Biol 2011; 2:241-2. [PMID: 19641743 DOI: 10.4161/cib.2.3.8158] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 02/10/2009] [Indexed: 11/19/2022] Open
Abstract
A wealth of recent studies has highlighted the diverse and important influences of carbon monoxide (CO) on cellular signaling pathways. Such studies have implicated CO, and the enzymes from which it is derived (heme oxygenases) as potential therapeutic targets, particularly (although not exclusively) in inflammation, immunity and cardiovascular disease.1 In a recent study,2 we demonstrated that CO inhibited cardiac L-type Ca(2+) channels. This effect arose due to the ability of CO to bind to mitochondria (presumably at complex IV of the electron transport chain) and so cause electron leak, which resulted in increased production of reactive oxygen species. These modulated the channel's activity through interactions with three cysteine residues in the cytosolic C-terminus of the channel's major, pore-forming subunit. Our study provided a potential mechanism for the cardioprotective effects of CO and also highlighted ion channels as a major potential target group for this gasotransmitter.
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Affiliation(s)
- Chris Peers
- Division of Cardiovascular and Neuronal Remodelling; Faculty of Medicine and Health; University of Leeds; Leeds, UK
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24
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Jimenez V, Henriquez M, Galanti N, Riquelme G. Electrophysiological characterization of potassium conductive pathways in Trypanosoma cruzi. J Cell Biochem 2011; 112:1093-102. [DOI: 10.1002/jcb.23023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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25
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Spermine attenuates carotid body glomus cell oxygen sensing by inhibiting L-type Ca²(+) channels. Respir Physiol Neurobiol 2010; 175:80-9. [PMID: 20863914 DOI: 10.1016/j.resp.2010.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 09/15/2010] [Accepted: 09/15/2010] [Indexed: 01/07/2023]
Abstract
An increase in intracellular Ca²(+) is crucial to O₂ sensing by the carotid body. Polyamines have been reported to modulate both the extracellular Ca²(+)-sensing receptor (CaR) and voltage-gated Ca²(+) channels in a number of cell types. Using RT-PCR and immunohistochemistry, the predominant voltage-gated Ca²(+) channels expressed in the adult rat carotid body were L (Ca(V)1.2) and N (Ca(V)2.2)-type. CaR mRNA could not be amplified from carotid bodies, but the protein was expressed in the nerve endings. Spermine inhibited the hypoxia-evoked catecholamine release from isolated carotid bodies and attenuated the depolarization- and hypoxia-evoked Ca²(+) influx into isolated glomus cells. In agreement with data from carotid body, recombinant Ca(V)1.2 was also inhibited by spermine. In contrast, the positive allosteric modulator of CaR, R-568, was without effect on hypoxia-induced catecholamine release from carotid bodies and depolarization-evoked Ca²(+) influx into glomus cells. These data show that spermine exerts a negative influence on carotid body O₂ sensing by inhibiting L-type Ca²(+) channels.
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26
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Telezhkin V, Brazier SP, Cayzac SH, Wilkinson WJ, Riccardi D, Kemp PJ. Mechanism of inhibition by hydrogen sulfide of native and recombinant BKCa channels. Respir Physiol Neurobiol 2010; 172:169-78. [PMID: 20576528 DOI: 10.1016/j.resp.2010.05.016] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 05/06/2010] [Accepted: 05/11/2010] [Indexed: 12/17/2022]
Abstract
Recent evidence suggests that H(2)S contributes to activation of the carotid body by hypoxia by inhibiting K(+) channels. Here, we determine both the molecular identity of the K(+) channel target within the carotid body and the biophysical characteristics of the H(2)S-evoked inhibition by analyzing native rat and human recombinant BK(Ca) channel activity in voltage-clamped, inside-out membrane patches. Rat glomus cells express the enzymes necessary for the endogenous generation of H(2)S, cystathionine-beta-synthase and cystathionine-gamma-lyase. H(2)S inhibits native carotid body and human recombinant BK(Ca) channels with IC(50) values of around 275 microM. Inhibition by H(2)S is rapid and reversible, works by a mechanism which is distinct from that suggested for CO gas regulation of this channel and does not involve an interaction with either the "Ca bowl" or residues distal to this Ca(2+)-sensing domain. These data show that BK(Ca) is a K(+) channel target of H(2)S, and suggest a mechanism to explain the H(2)S-dependent component of O(2) sensing in the carotid body.
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Affiliation(s)
- Vsevolod Telezhkin
- Division of Pathophysiology and Repair, School of Biosciences, Cardiff University, Cardiff, UK
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27
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Li Q, Sun B, Wang X, Jin Z, Zhou Y, Dong L, Jiang LH, Rong W. A crucial role for hydrogen sulfide in oxygen sensing via modulating large conductance calcium-activated potassium channels. Antioxid Redox Signal 2010; 12:1179-89. [PMID: 19803741 DOI: 10.1089/ars.2009.2926] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Hydrogen sulfide (H(2)S) is an important signaling molecule produced from L-cysteine by cystathionine beta-synthetase (CBS) or cystathionine gamma-lyase (CSE). Here we examined the role of H(2)S in the oxygen-sensing function of the carotid body chemoreceptors, where the large conductance Ca(2+)-activated potassium channel (BK(Ca)) plays a key role. In the isolated mouse carotid body/sinus nerve preparations, the H(2)S donor, NaHS, excited the chemoreceptor afferent nerves in a concentration-dependent manner that was reversed by carbon monoxide donor. The NaHS-evoked excitation was abolished by removing extracellular Ca(2+), or using Cd(2+), pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid and hexomethonium, suggesting that H(2)S evokes release of ATP/ACh from type I glomus cells of the carotid body. The chemoreceptor afferent activation by hypoxia was decreased remarkably using CBS inhibitors, amino oxyacetic acid (AOAA) and hydroxylamine, but not CSE inhibitors, propargylglycine and beta-cyano-L-alanine, despite expression of both enzymes in type I glomus cells. In these cells, the BK(Ca) currents were inhibited by hypoxia and such inhibition was mimicked by NaHS and diminished by AOAA. Finally, mice hyperventilated in response to hypoxia, which was prevented by CBS inhibitors. These data suggest that H(2)S plays a crucial role in mediating the response of carotid body chemoreceptors to hypoxia via modulating the BK(Ca) channels.
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Affiliation(s)
- Qian Li
- Department of Physiology, Shanghai Jiaotong University School of Medicine, Shanghai, China
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28
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Kemp PJ, Telezhkin V, Wilkinson WJ, Mears R, Hanmer SB, Gadeberg HC, Müller CT, Riccardi D, Brazier SP. Enzyme-Linked Oxygen Sensing by Potassium Channels. Ann N Y Acad Sci 2009; 1177:112-8. [DOI: 10.1111/j.1749-6632.2009.05025.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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29
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Hypoxia inhibits maturation and trafficking of hERG K(+) channel protein: Role of Hsp90 and ROS. Biochem Biophys Res Commun 2009; 388:212-6. [PMID: 19654002 DOI: 10.1016/j.bbrc.2009.07.149] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 07/26/2009] [Indexed: 01/08/2023]
Abstract
We previously reported that reactive oxygen species (ROS) generated during hypoxia decrease hERG current density and protein expression in HEK cells stably expressing hERG protein. In the present study, we investigated the molecular mechanisms involved in hypoxia-induced downregulation of hERG protein. Culturing cells at low temperatures and addition of chemical chaperones during hypoxia restored hERG expression and currents to normoxic levels while antiarrhythmic drugs, which selectively block hERG channels, had no effect on hERG protein levels. Pulse chase studies showed that hypoxia blocks maturation of the core glycosylated form in the endoplasmic reticulum (ER) to the fully glycosylated form on the cell surface. Co-immunoprecipitation experiments revealed that hypoxia inhibited interaction of hERG with Hsp90 chaperone required for maturation, which was restored in the presence of ROS scavengers. These results demonstrate that ROS generated during hypoxia prevents maturation of the hERG protein by inhibiting Hsp90 interaction resulting in decreased protein expression and currents.
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30
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Dallas ML, Scragg JL, Wyatt CN, Ross F, Hardie DG, Evans AM, Peers C. Modulation of O(2) sensitive K (+) channels by AMP-activated protein kinase. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 648:57-63. [PMID: 19536465 DOI: 10.1007/978-90-481-2259-2_6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Hypoxic inhibition of K(+) channels in type I cells is believed to be of central importance in carotid body chemotransduction. We have recently suggested that hypoxic channel inhibition is mediated by AMP-activated protein kinase (AMPK). Here, we have further explored the modulation by AMPK of recombinant K(+) channels (expressed in HEK293 cells) whose native counterparts are considered O(2)-sensitive in the rat carotid body. Inhibition of maxiK channels by AMPK activation with AICAR was found to be independent of [Ca(2+)](i) and occurred regardless of whether the alpha subunit was co-expressed with an auxiliary beta subunit. All effects of AICAR were fully reversed by the AMPK inhibitor compound C. MaxiK channels were also inhibited by the novel AMPK activator A-769662 and by intracellular dialysis with the constitutively active, truncated AMPK mutant, T172D. The molecular identity of the O(2)-sensitive leak K(+) conductance in rat type I cells remains unclear, but shares similarities with TASK-1 and TASK-3. Recombinant TASK-1 was insensitive to AICAR. However, TASK-3 was inhibited by either AICAR or A-769662 in a manner which was reversed by compound C. These data highlight a role for AMPK in the modulation of two proposed O(2) sensitive K(+) channels found in the carotid body.
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Affiliation(s)
- M L Dallas
- Division of Cardiovascular and Neuronal Remodelling, Leeds Institute of Genetics, Health & Therapeutics University of Leeds, Leeds LS2 9JT, UK.
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Fähling M. Cellular oxygen sensing, signalling and how to survive translational arrest in hypoxia. Acta Physiol (Oxf) 2009; 195:205-30. [PMID: 18764866 DOI: 10.1111/j.1748-1716.2008.01894.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Hypoxia is a consequence of inadequate oxygen availability. At the cellular level, lowered oxygen concentration activates signal cascades including numerous receptors, ion channels, second messengers, as well as several protein kinases and phosphatases. This, in turn, activates trans-factors like transcription factors, RNA-binding proteins and miRNAs, mediating an alteration in gene expression control. Each cell type has its unique constellation of oxygen sensors, couplers and effectors that determine the activation and predominance of several independent hypoxia-sensitive pathways. Hence, altered gene expression patterns in hypoxia result from a complex regulatory network with multiple divergences and convergences. Although hundreds of genes are activated by transcriptional control in hypoxia, metabolic rate depression, as a consequence of reduced ATP level, causes inhibition of mRNA translation. In a multi-phase response to hypoxia, global protein synthesis is suppressed, mainly by phosphorylation of eIF2-alpha by PERK and inhibition of mTOR, causing suppression of 5'-cap-dependent mRNA translation. Growing evidence suggests that mRNAs undergo sorting at stress granules, which determines the fate of mRNA as to whether being translated, stored, or degraded. Data indicate that translation is suppressed only at 'free' polysomes, but is active at subsets of membrane-bound ribosomes. The recruitment of specific mRNAs into subcellular compartments seems to be crucial for local mRNA translation in prolonged hypoxia. Furthermore, ribosomes themselves may play a significant role in targeting mRNAs for translation. This review summarizes the multiple facets of the cellular adaptation to hypoxia observed in mammals.
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Affiliation(s)
- M Fähling
- Institut für Vegetative Physiologie, Charité, Universitätsmedizin Berlin, Berlin, Germany.
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Chavez A, Miranda LF, Pichiule P, Chavez JC. Mitochondria and hypoxia-induced gene expression mediated by hypoxia-inducible factors. Ann N Y Acad Sci 2009; 1147:312-20. [PMID: 19076453 DOI: 10.1196/annals.1427.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The influence of mitochondrial activity on gene expression programs, particularly those involved in neuroprotection and repair, is likely to play an important role in the pathophysiology of neurodegenerative diseases. One such gene expression program is activated by the cellular pathway that senses a decrease in optimal oxygen levels and leads to activation of a family of transcriptional activators called hypoxia-inducible factors (HIFs). HIFs are members of the bHLH-PAS family of transcription factors and are heterodimers composed of HIF-alpha and HIF-beta (also known as aryl hydrocarbon receptor nuclear translocator) subunits that bind to canonical DNA sequences (hypoxia-regulated elements) in the promoters or enhancers of target genes. HIFs activate the expression of more than a hundred genes encoding proteins that regulate cell metabolism, survival, angiogenesis, vascular tone, hematopoiesis, and other functions. There is considerable evidence showing a bidirectional crosstalk between mitochondrial signals and HIF activity. For instance, mitochondrial reactive oxygen species and metabolic substrates from the tricarboxylic acid cycle are implicated in the regulation of the HIF pathway. Conversely, HIF activity leads to the expression of target genes that influence mitochondrial function. In this chapter we will review the complex interactions between mitochondria and the HIF pathway and we will discuss the relevance of this interaction for metabolic adaptation to hypoxia.
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Affiliation(s)
- Angela Chavez
- Department of Biology, Cayetano Heredia University, Lima, Peru.
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Telezhkin V, Brazier S, Cayzac S, Müller C, Riccardi D, Kemp P. Hydrogen Sulfide Inhibits Human BKCa Channels. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 648:65-72. [DOI: 10.1007/978-90-481-2259-2_7] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Cysteine residues in the C-terminal tail of the human BK(Ca)alpha subunit are important for channel sensitivity to carbon monoxide. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 648:49-56. [PMID: 19536464 DOI: 10.1007/978-90-481-2259-2_5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the presence of oxygen (O(2)), carbon monoxide (CO) is synthesised from heme by endogenous hemeoxygenases, and is a powerful activator of BK(Ca) channels. This transduction pathway has been proposed to contribute to cellular O(2) sensing in rat carotid body. In the present study we have explored the role that four cysteine residues (C820, C911, C995 and C1028), located in the vicinity of the "calcium bowl" of C-terminal of human BK(Ca)-alphasubunit, have on channel CO sensitivity. Mutant BK(Ca)-alphasubunits were generated by site-directed mutagenesis (single, double and triple cysteine residue substitutions with glycine residues) and were transiently transfected into HEK 293 cells before subsequent analysis in inside-out membrane patches. Potassium cyanide (KCN) completely abolished activation of wild type BK(Ca) channels by the CO donor, tricarbonyldichlororuthenium (II) dimer, at 100microM. In the absence of KCN the CO donor increased wild-type channel activity in a concentration-dependent manner, with an EC(50) of ca. 50microM. Single cysteine point mutations of residues C820, C995 and C1028 affected neither channel characteristics nor CO EC(50) values. In contrast, the CO sensitivity of the C911G mutation was significantly decreased (EC(50) ca. 100 M). Furthermore, all double and triple mutants which contained the C911G substitution exhibited reduced CO sensitivity, whilst those which did not contain this mutation displayed essentially unaltered CO EC(50) values. These data highlight that a single cysteine residue is crucial to the activation of BK(Ca) by CO. We suggest that CO may bind to this channel subunit in a manner similar to the transition metal-dependent co-ordination which is characteristic of several enzymes, such as CO dehydrogenase.
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Nanduri J, Wang N, Bergson P, Yuan G, Ficker E, Prabhakar NR. Mitochondrial reactive oxygen species mediate hypoxic down-regulation of hERG channel protein. Biochem Biophys Res Commun 2008; 373:309-14. [DOI: 10.1016/j.bbrc.2008.06.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Accepted: 06/06/2008] [Indexed: 11/17/2022]
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Dirnagl U, Meisel A. Endogenous neuroprotection: mitochondria as gateways to cerebral preconditioning? Neuropharmacology 2008; 55:334-44. [PMID: 18402985 DOI: 10.1016/j.neuropharm.2008.02.017] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Revised: 02/24/2008] [Accepted: 02/26/2008] [Indexed: 01/06/2023]
Abstract
From single to multicellular organisms, protective mechanisms have evolved against endogenous and exogenous noxious stimuli. Preconditioning paradigms, in which stimulation below the threshold of injury results in subsequent protection of the brain, have played an important role in elucidating such endogenous protective mechanisms. Consequently, over the past decades numerous signaling pathways have been discovered by which the brain senses and reacts to such insults as neurotoxins, substrate deprivation, or inflammation. Research on preconditioning is aimed at understanding endogenous neuroprotection to boost it, or to supplement its effectors therapeutically once damage to the brain has occurred, such as after stroke or brain trauma. Another goal of establishing preconditioning protocols is to induce endogenous neuroprotection in anticipation of incipient brain damage. Currently several endogenous neuroprotectants are being investigated in controlled clinical trials. In the present review we will give a short overview on the signals, sensors, transducers, and effectors of endogenous neuroprotection. We will first focus on common mechanisms, on which pathways of endogenous neuroprotection converge, and in particular on mitochondria, which may be considered master integrators of endogenous neuroprotection. We will then discuss various applications of preconditioning, including pharmacological and anesthetic preconditioning, as well as postconditioning, and explore the prospects of endogenous neuroprotective therapeutic approaches.
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Affiliation(s)
- Ulrich Dirnagl
- Department of Experimental Neurology, Center for Stroke Research Berlin, Berlin, Germany.
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Abstract
Mitochondrial respiration is responsible for more than 90% of oxygen consumption in humans. Cells utilize oxygen as the final electron acceptor in the aerobic metabolism of glucose to generate ATP which fuels most active cellular processes. Consequently, a drop in tissue oxygen levels to the point where oxygen demand exceeds supply (termed hypoxia) leads rapidly to metabolic crisis and represents a severe threat to ongoing physiological function and ultimately, viability. Because of the central role of oxygen in metabolism, it is perhaps not surprising that we have evolved an efficient and rapid molecular response system which senses hypoxia in cells, leading to the induction of an array of adaptive genes which facilitate increased oxygen supply and support anaerobic ATP generation. This response is governed by HIF (hypoxia-inducible factor). The oxygen sensitivity of this pathway is conferred by a family of hydroxylases which repress HIF activity in normoxia allowing its rapid activation in hypoxia. Because of its importance in a diverse range of disease states, the mechanism by which cells sense hypoxia and transduce a signal to the HIF pathway is an area of intense investigation. Inhibition of mitochondrial function reverses hypoxia-induced HIF leading to speculation of a role for mitochondria in cellular oxygen sensing. However, the nature of the signal between mitochondria and oxygen-sensing hydroxylase enzymes has remained controversial. In the present review, two models of the role for mitochondria in oxygen sensing will be discussed and recent evidence will be presented which raises the possibility that these two models which implicate ROS (reactive oxygen species) and oxygen redistribution respectively may complement each other and facilitate rapid and dynamic activation of the HIF pathway in hypoxia.
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