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Angulo J, Fernández A, Sevilleja-Ortiz A, Sánchez-Ferrer A, Rodríguez-Mañas L, El Assar M. Upregulation of Orai Channels Contributes to Aging-Related Vascular Alterations in Rat Coronary Arteries. Int J Mol Sci 2023; 24:13402. [PMID: 37686206 PMCID: PMC10487684 DOI: 10.3390/ijms241713402] [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: 07/13/2023] [Revised: 08/11/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Vascular territories display heterogeneous sensitivity to the impacts of aging. The relevance of the STIM/Orai system to vascular function depends on the vascular bed. We aimed to evaluate the contribution of the STIM/Orai system to aging-related vascular dysfunction in rat coronary circulation. Vascular function was evaluated according to myography in coronary arteries from young (three-month-old) and older (twenty-month-old) rats. The effects of aging and STIM/Orai inhibition on the contraction and relaxation of the coronary arteries and on the protein expression of STIM-1, Orai1, and Orai3 in these vessels were determined. Aging-related hypercontractility to serotonin and endothelin-1 in arteries from male rats was reversed by STIM/Orai inhibition with YM-58483 or by specifically blocking the Orai1 channel with Synta66. The inhibitory effects of Synta66 on coronary vasoconstriction were also observed in older female rats. YM-58483 relaxed serotonin- but not KCl-contracted arteries from males. STIM/Orai inhibition improved defective endothelial vasodilations in aged arteries, even in the presence of NO synthase and cyclooxygenase inhibitors, but not in KCl-contracted segments. YM-58483 significantly enhanced relaxations to calcium-activated potassium channel stimulation in aged vessels. Increased protein expression of Orai1 and Orai3 was detected in arterial homogenates and sections from older rats. Upregulation of the Orai channel contributes to aging-related coronary dysfunction, revealing a potential target in reducing CVD risk.
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Affiliation(s)
- Javier Angulo
- Servicio de Histología, Unidad de Investigación Cardiovascular (IRYCIS/UFV), Hospital Universitario Ramón y Cajal, 28034 Madrid, Spain; (A.F.); (A.S.-O.)
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, 28029 Madrid, Spain;
| | - Argentina Fernández
- Servicio de Histología, Unidad de Investigación Cardiovascular (IRYCIS/UFV), Hospital Universitario Ramón y Cajal, 28034 Madrid, Spain; (A.F.); (A.S.-O.)
| | - Alejandro Sevilleja-Ortiz
- Servicio de Histología, Unidad de Investigación Cardiovascular (IRYCIS/UFV), Hospital Universitario Ramón y Cajal, 28034 Madrid, Spain; (A.F.); (A.S.-O.)
| | - Alberto Sánchez-Ferrer
- Fundación para la Investigación Biomédica, Hospital Universitario de Getafe, 28905 Getafe, Spain;
| | - Leocadio Rodríguez-Mañas
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Servicio de Geriatría, Hospital Universitario de Getafe, 28905 Getafe, Spain
| | - Mariam El Assar
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Fundación para la Investigación Biomédica, Hospital Universitario de Getafe, 28905 Getafe, Spain;
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Soloviev A, Ivanova I, Melnyk M, Dobrelia N, Khromov A. Hypoxic pulmonary vasoconstriction is lacking in rats with type 1 diabetes. Clin Exp Pharmacol Physiol 2019; 46:1022-1029. [PMID: 31314914 DOI: 10.1111/1440-1681.13137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 11/28/2022]
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is the most important feature of intact lung circulation that matches local blood perfusion to ventilation. The main goal of this work was to study the effects of diabetes on the development of HPV in rats. The experimental design comprised diabetes mellitus induction by streptozotocin, video-morphometric measurements of the lumen area of intrapulmonary arteries (iPAs) using perfused lung tissue slices and patch-clamp techniques. It was shown that iPA lumen size was significantly reduced under physical and chemical hypoxia (7-10 mm Hg) in normal iPA, but, on the contrary, it clearly increased in diabetic lung slices. The amplitude of the outward K+ current in diabetic iPAs smooth muscle cells (SMCs) was two-fold greater than that seen in healthy cells. Chemical hypoxia led to significant decrease in the amplitude of the K+ outward current in healthy iPA SMCs while it was without effect in diabetic cells. The data obtained clearly indicate a significant dysregulation of vascular tone in pulmonary circulation under diabetes, ie diabetes damages the adaptive mechanism for regulating blood flow from poorly ventilated to better ventilated regions of the lung under hypoxia. This effect could be clinically important for patients with diabetes who have acute or chronic lung diseases associated with the lack of blood oxygenation.
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Affiliation(s)
- Anatoly Soloviev
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine
| | - Irina Ivanova
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine
| | - Mariia Melnyk
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine.,Bogomoletz Institute of Physiology, National Academy of Science of Ukraine, Kyiv, Ukraine
| | - Nataliia Dobrelia
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine
| | - Alexander Khromov
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine
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Inhibition of RhoA/ROCK signaling pathway ameliorates hypoxic pulmonary hypertension via HIF-1α-dependent functional TRPC channels. Toxicol Appl Pharmacol 2019; 369:60-72. [DOI: 10.1016/j.taap.2019.02.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 11/19/2022]
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Nagaraj C, Tabeling C, Nagy BM, Jain PP, Marsh LM, Papp R, Pienn M, Witzenrath M, Ghanim B, Klepetko W, Weir EK, Heschl S, Kwapiszewska G, Olschewski A, Olschewski H. Hypoxic vascular response and ventilation/perfusion matching in end-stage COPD may depend on p22phox. Eur Respir J 2017; 50:50/1/1601651. [PMID: 28729471 DOI: 10.1183/13993003.01651-2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 04/10/2017] [Indexed: 11/05/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease in which the amount of emphysema and airway disease may be very different between individuals, even in end-stage disease. Emphysema formation may be linked to the involvement of the small pulmonary vessels. The NAPDH oxidase (Nox) family is emerging as a key disease-related factor in vascular diseases, but currently its role in hypoxia-induced pulmonary remodelling in COPD remains unclear.Here we investigate the role of p22phox, a regulatory subunit of Nox, in COPD lungs, hypoxic pulmonary vasoconstriction (HPV), hypoxia-induced pulmonary vascular remodelling and pulmonary hypertension.In COPD, compared to control lungs, p22phox expression was significantly reduced. The expression was correlated positively with mean pulmonary arterial pressure and oxygenation index and negatively with the diffusing capacity of the lung for carbon monoxide (p<0.02). This suggests a role of p22phox in ventilation/perfusion ratio matching, vascular remodelling and loss of perfused lung area. In p22phox-/- mice, HPV was significantly impaired. In the chronic hypoxic setting, lack of p22phox was associated with improved right ventricular function and decreased pulmonary vascular remodelling.p22phox-dependent Nox plays an important role in the COPD phenotype, by its action on phase II HPV and chronic vascular remodelling.
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Affiliation(s)
- Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Christoph Tabeling
- Dept of Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Bence M Nagy
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Pritesh P Jain
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Leigh M Marsh
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Rita Papp
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Michael Pienn
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Martin Witzenrath
- Dept of Infectious Diseases and Pulmonary Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Bahil Ghanim
- Dept of Thoracic Surgery, Division of Surgery, Medical University Vienna, Vienna, Austria
| | - Walter Klepetko
- Dept of Thoracic Surgery, Division of Surgery, Medical University Vienna, Vienna, Austria
| | - E Kenneth Weir
- Dept of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Stefan Heschl
- Dept of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, Austria
| | - Grazyna Kwapiszewska
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria .,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Horst Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria.,Division of Pulmonology, Dept of Internal Medicine, Medical University of Graz, Graz, Austria
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Alrifaiy A, Borg J, Lindahl OA, Ramser K. A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy- first investigations of single biological cells. Biomed Eng Online 2015; 14:36. [PMID: 25907197 PMCID: PMC4407798 DOI: 10.1186/s12938-015-0024-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 03/17/2015] [Indexed: 12/05/2022] Open
Abstract
The response and the reaction of the brain system to hypoxia is a vital research subject that requires special instrumentation. With this research subject in focus, a new multifunctional lab-on-a-chip (LOC) system with control over the oxygen content for studies on biological cells was developed. The chip was designed to incorporate the patch clamp technique, optical tweezers and absorption spectroscopy. The performance of the LOC was tested by a series of experiments. The oxygen content within the channels of the LOC was monitored by an oxygen sensor and verified by simultaneously studying the oxygenation state of chicken red blood cells (RBCs) with absorption spectra. The chicken RBCs were manipulated optically and steered in three dimensions towards a patch-clamp micropipette in a closed microfluidic channel. The oxygen level within the channels could be changed from a normoxic value of 18% O 2 to an anoxic value of 0.0-0.5% O 2. A time series of 3 experiments were performed, showing that the spectral transfer from the oxygenated to the deoxygenated state occurred after about 227 ± 1 s and a fully developed deoxygenated spectrum was observed after 298 ± 1 s, a mean value of 3 experiments. The tightness of the chamber to oxygen diffusion was verified by stopping the flow into the channel system while continuously recording absorption spectra showing an unchanged deoxygenated state during 5400 ± 2 s. A transfer of the oxygenated absorption spectra was achieved after 426 ± 1 s when exposing the cell to normoxic buffer. This showed the long time viability of the investigated cells. Successful patching and sealing were established on a trapped RBC and the whole-cell access (Ra) and membrane (Rm) resistances were measured to be 5.033 ± 0.412 M Ω and 889.7 ± 1.74 M Ω respectively.
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Affiliation(s)
- Ahmed Alrifaiy
- Institute of Neuroscience and Physiology, Section of physiology, Gothenburg University - Sahlgrenska Academy, Göteborg, 405 30, Sweden. .,Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, 971 87, Sweden. .,CMTF, Centre for Biomedical Engineering and Physics, Luleå and Umeå, Sweden.
| | - Johan Borg
- Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, 971 87, Sweden.
| | - Olof A Lindahl
- Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, 971 87, Sweden. .,CMTF, Centre for Biomedical Engineering and Physics, Luleå and Umeå, Sweden. .,Department of Radiation Sciences, Biomedical Engineering, Umeå, 901 87, Sweden. .,Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, 971 87, Sweden.
| | - Kerstin Ramser
- Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, 971 87, Sweden. .,CMTF, Centre for Biomedical Engineering and Physics, Luleå and Umeå, Sweden. .,Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, 971 87, Sweden.
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Veit F, Pak O, Brandes RP, Weissmann N. Hypoxia-dependent reactive oxygen species signaling in the pulmonary circulation: focus on ion channels. Antioxid Redox Signal 2015; 22:537-52. [PMID: 25545236 PMCID: PMC4322788 DOI: 10.1089/ars.2014.6234] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
SIGNIFICANCE An acute lack of oxygen in the lung causes hypoxic pulmonary vasoconstriction, which optimizes gas exchange. In contrast, chronic hypoxia triggers a pathological vascular remodeling causing pulmonary hypertension, and ischemia can cause vascular damage culminating in lung edema. RECENT ADVANCES Regulation of ion channel expression and gating by cellular redox state is a widely accepted mechanism; however, it remains a matter of debate whether an increase or a decrease in reactive oxygen species (ROS) occurs under hypoxic conditions. Ion channel redox regulation has been described in detail for some ion channels, such as Kv channels or TRPC6. However, in general, information on ion channel redox regulation remains scant. CRITICAL ISSUES AND FUTURE DIRECTIONS In addition to the debate of increased versus decreased ROS production during hypoxia, we aim here at describing and deciphering why different oxidants, under different conditions, can cause both activation and inhibition of channel activity. While the upstream pathways affecting channel gating are often well described, we need a better understanding of redox protein modifications to be able to determine the complexity of ion channel redox regulation. Against this background, we summarize the current knowledge on hypoxia-induced ROS-mediated ion channel signaling in the pulmonary circulation.
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Affiliation(s)
- Florian Veit
- 1 Excellence Cluster Cardiopulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), German Center for Lung Research (DZL) , Giessen, Germany
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Li SS, Ran YJ, Zhang DD, Li SZ, Zhu D. MicroRNA-190 regulates hypoxic pulmonary vasoconstriction by targeting a voltage-gated K⁺ channel in arterial smooth muscle cells. J Cell Biochem 2014; 115:1196-205. [PMID: 24446351 DOI: 10.1002/jcb.24771] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 01/16/2014] [Indexed: 01/02/2023]
Abstract
Pulmonary arterial hypertension (PAH) is associated with sustained vasoconstriction, profound structural remodeling of vasculatures and alterations in Ca(2+) homeostasis in arterial smooth muscle cells (SMCs), while the underlying mechanisms are still elusive. By regulating the expression of proteins, microRNAs (miRNAs) are known to play an important role in cell fates including differentiation, apoptosis and proliferation, and may be involved in the development of PAH. Based on our previous study, hypoxia produced a significant increase of the miR-190 level in the pulmonary artery (PA), here, we used synthetic miR-190 to mimic the increase in hypoxic conditions and showed evidence for the effects of miR-190 on pulmonary arterial vasoconstriction and Ca(2+) influx in arterial SMCs. Synthetic miR-190 remarkably enhanced the vasoconstriction responses to phenylephrine (PE) and KCl. The voltage-gated K(+) channel subfamily member, Kcnq5, mRNA was shown to be a target for miR-190. Meanwhile, miR-190 antisense oligos can partially reverse the effects of miR-190 on PASMCs and PAs. Therefore, these results suggest that miR-190 appears to be a positive regulator of Ca(2+) influx, and plays an important role in hypoxic pulmonary vascular constriction.
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Affiliation(s)
- Shan-Shan Li
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, China; Department of Biopharmaceutical Key Laboratory of Heilongjiang Province, 157 Baojian Road, Nangang District, Harbin, Heilongjiang, 150081, PR China
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NS1619-induced vasodilation is enhanced and differentially mediated in chronically hypoxic lungs. Lung 2014; 192:811-7. [PMID: 25104232 DOI: 10.1007/s00408-014-9633-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/24/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE To identify the effect of the benzimidazalone derivative, NS1619, on modulating pulmonary vascular tone in lungs from rats exposed to normoxia (21% FiO2) or chronic hypoxia (10% FiO2) for three weeks. METHODS Isolated perfused lungs were preconstricted (U46619), and dose-dependent vasodilation to NS1619 was assessed. To elucidate the mechanisms responsible, NS1619 vasodilatory responses were assessed following inhibition of large-conductance Ca(2+)-activated (BKCa; iberiotoxin and paxilline), L-type Ca2+ (nifedipine), K+ (tetraethylammonium), Cl- (niflumic acid), and cation/TRP (lanthanum) channels, as well as nitric oxide synthase (L-NAME). RESULTS Compared to normoxia, NS1619-induced vasodilation was significantly greater following hypoxia; however, NO-dependent vasodilation and BKCa-mediated vasodilation, in response to NS1619, were similar in the normoxic and hypoxic lungs. In contrast, direct activation of L-type Ca2+ and non-BKCa K+ channel was involved in the NS1619-induced vasodilation only in hypoxic lungs. CONCLUSIONS NS1619 causes pulmonary vasodilation by affecting multiple complementary pathways, including stimulation of NO production, activation of BKCa channels, other TEA-sensitive K+ channels, and L-type Ca2+ channels, and could be considered as a therapeutic agent in hypoxic PH.
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Role of voltage-gated potassium channels in pathogenesis of chronic pulmonary heart disease. ACTA ACUST UNITED AC 2013; 33:644-649. [DOI: 10.1007/s11596-013-1174-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 07/03/2013] [Indexed: 01/14/2023]
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Zhang J, Zhou J, Cai L, Lu Y, Wang T, Zhu L, Hu Q. Extracellular calcium-sensing receptor is critical in hypoxic pulmonary vasoconstriction. Antioxid Redox Signal 2012; 17:471-84. [PMID: 22098336 DOI: 10.1089/ars.2011.4168] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
AIMS The initiation of hypoxic pulmonary vasoconstriction (HPV) involves an increase in cytosolic calcium ([Ca(2+)](i)) in pulmonary artery (PA) smooth muscle cells (PASMCs). Both the processes depend on extracellular Ca(2+). Extracellular Ca(2+) can be sensed by extracellular calcium-sensing receptor (CaSR). This study aims at determining whether CaSR is pivotal in the initiation of HPV. RESULTS Experiments were performed in cultured PASMCs, isolated PAs, and rats including CaSR knockdown preparations. Both hypoxia and H(2)O(2) equivalent to the level achieved by hypoxia increased [Ca(2+)](i) in an extracellular Ca(2+)-dependent manner in PASMCs, and this was inhibited by CaSR knockdown or its negative allosteric modulator, Calhex231. Hypoxia-increased H(2)O(2) generation was diminished by mitochondria depletion. Mitochondria depletion abolished hypoxia-induced [Ca(2+)](i) increase (HICI), which was reversed by H(2)O(2) repletion. CaSR knockdown or Calhex231, however, prevented the reversible effect of H(2)O(2). HICI was abolished by catalase-polyethylene glycol (PEG-Catalase), not superoxide dismutase-polyethylene glycol (PEG-SOD) pretreatment, attenuated by ryanodine receptor3-knockdown or inhibition of store-operated Ca(2+) entry. HPV in vitro and in vivo was inhibited by Calhex231 and by CaSR knockdown. INNOVATION A novel mechanism underlying HPV is revealed by the role of CaSR in orchestrating reactive oxygen species and [Ca(2+)](i) signaling. CONCLUSIONS The activation of mitochondrial H(2)O(2)-sensitized CaSR by extracellular Ca(2+) mediates HICI in PASMCs and, thus, initiates HPV.
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Affiliation(s)
- Jiwei Zhang
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology (HUST), Wuhan, People's Republic of China
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Koos BJ. Adenosine A₂a receptors and O₂ sensing in development. Am J Physiol Regul Integr Comp Physiol 2011; 301:R601-22. [PMID: 21677265 DOI: 10.1152/ajpregu.00664.2010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Reduced mitochondrial oxidative phosphorylation, via activation of adenylate kinase and the resulting exponential rise in the cellular AMP/ATP ratio, appears to be a critical factor underlying O₂ sensing in many chemoreceptive tissues in mammals. The elevated AMP/ATP ratio, in turn, activates key enzymes that are involved in physiologic adjustments that tend to balance ATP supply and demand. An example is the conversion of AMP to adenosine via 5'-nucleotidase and the resulting activation of adenosine A(₂A) receptors, which are involved in acute oxygen sensing by both carotid bodies and the brain. In fetal sheep, A(₂A) receptors associated with carotid bodies trigger hypoxic cardiovascular chemoreflexes, while central A(₂A) receptors mediate hypoxic inhibition of breathing and rapid eye movements. A(₂A) receptors are also involved in hypoxic regulation of fetal endocrine systems, metabolism, and vascular tone. In developing lambs, A(₂A) receptors play virtually no role in O₂ sensing by the carotid bodies, but brain A(₂A) receptors remain critically involved in the roll-off ventilatory response to hypoxia. In adult mammals, A(₂A) receptors have been implicated in O₂ sensing by carotid glomus cells, while central A(₂A) receptors likely blunt hypoxic hyperventilation. In conclusion, A(₂A) receptors are crucially involved in the transduction mechanisms of O₂ sensing in fetal carotid bodies and brains. Postnatally, central A(₂A) receptors remain key mediators of hypoxic respiratory depression, but they are less critical for O₂ sensing in carotid chemoreceptors, particularly in developing lambs.
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Affiliation(s)
- Brian J Koos
- Department of Obstetrics and Gynecology; Brain Research Institute, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA.
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Wang YX, Zheng YM. Role of ROS signaling in differential hypoxic Ca2+ and contractile responses in pulmonary and systemic vascular smooth muscle cells. Respir Physiol Neurobiol 2010; 174:192-200. [PMID: 20713188 DOI: 10.1016/j.resp.2010.08.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 08/06/2010] [Accepted: 08/09/2010] [Indexed: 01/25/2023]
Abstract
Hypoxia causes a large increase in [Ca2+]i and attendant contraction in pulmonary artery smooth muscle cells (PASMCs), but not in systemic artery SMCs. The different responses meet the respective functional needs in these two distinct vascular myocytes; however, the underlying molecular mechanisms are not well known. We and other investigators have provided extensive evidence to reveal that voltage-dependent K+ (KV) channels, canonical transient receptor potential (TRPC) channels, ryanodine receptor Ca2+ release channels (RyRs), cyclic adenosine diphosphate-ribose, FK506 binding protein 12.6, protein kinase C, NADPH oxidase and reactive oxygen species (ROS) are the essential effectors and signaling intermediates in the hypoxic increase in [Ca2+]i in PASMCs and HPV, but they may not primarily underlie the diverse cellular responses in pulmonary and systemic vascular myocytes. Hypoxia significantly increases mitochondrial ROS generation in PASMCs, which can induce intracellular Ca2+ release by opening RyRs, and may also cause extracellular Ca2+ influx by inhibiting KV channels and activating TRPC channels, leading to a large increase in [Ca2+]i in PASMCs and HPV. In contrast, hypoxia has no or a minor effect on mitochondrial ROS generation in systemic SMCs, thereby causing no change or a negligible increase in [Ca2+]i and contraction. Further preliminary work indicates that Rieske iron-sulfur protein in the mitochondrial complex III may perhaps serve as a key initial molecular determinant for the hypoxic increase in [Ca2+]i in PASMCs and HPV, suggesting its potential important role in different cellular changes to respond to hypoxic stimulation in pulmonary and systemic artery myocytes. All these findings have greatly improved our understanding of the molecular processes for the differential hypoxic Ca2+ and contractile responses in vascular SMCs from distinct pulmonary and systemic circulation systems.
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Affiliation(s)
- Yong-Xiao Wang
- Center for Cardiovascular Sciences, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, USA.
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