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MacMillan S, Burns DP, O'Halloran KD, Evans AM. SubSol-HIe is an AMPK-dependent hypoxia-responsive subnucleus of the nucleus tractus solitarius that coordinates the hypoxic ventilatory response and protects against apnoea in mice. Pflugers Arch 2024; 476:1087-1107. [PMID: 38635058 PMCID: PMC11166843 DOI: 10.1007/s00424-024-02957-6] [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: 12/13/2023] [Revised: 03/24/2024] [Accepted: 03/31/2024] [Indexed: 04/19/2024]
Abstract
Functional magnetic resonance imaging (fMRI) suggests that the hypoxic ventilatory response is facilitated by the AMP-activated protein kinase (AMPK), not at the carotid bodies, but within a subnucleus (Bregma -7.5 to -7.1 mm) of the nucleus tractus solitarius that exhibits right-sided bilateral asymmetry. Here, we map this subnucleus using cFos expression as a surrogate for neuronal activation and mice in which the genes encoding the AMPK-α1 (Prkaa1) and AMPK-α2 (Prkaa2) catalytic subunits were deleted in catecholaminergic cells by Cre expression via the tyrosine hydroxylase promoter. Comparative analysis of brainstem sections, relative to controls, revealed that AMPK-α1/α2 deletion inhibited, with right-sided bilateral asymmetry, cFos expression in and thus activation of a neuronal cluster that partially spanned three interconnected anatomical nuclei adjacent to the area postrema: SolDL (Bregma -7.44 mm to -7.48 mm), SolDM (Bregma -7.44 mm to -7.48 mm) and SubP (Bregma -7.48 mm to -7.56 mm). This approximates the volume identified by fMRI. Moreover, these nuclei are known to be in receipt of carotid body afferent inputs, and catecholaminergic neurons of SubP and SolDL innervate aspects of the ventrolateral medulla responsible for respiratory rhythmogenesis. Accordingly, AMPK-α1/α2 deletion attenuated hypoxia-evoked increases in minute ventilation (normalised to metabolism), reductions in expiration time, and increases sigh frequency, but increased apnoea frequency during hypoxia. The metabolic response to hypoxia in AMPK-α1/α2 knockout mice and the brainstem and spinal cord catecholamine levels were equivalent to controls. We conclude that within the brainstem an AMPK-dependent, hypoxia-responsive subnucleus partially spans SubP, SolDM and SolDL, namely SubSol-HIe, and is critical to coordination of active expiration, the hypoxic ventilatory response and defence against apnoea.
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Affiliation(s)
- Sandy MacMillan
- Centre for Discovery Brain Sciences, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - David P Burns
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - A Mark Evans
- Centre for Discovery Brain Sciences, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK.
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2
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Geng Y, Hu Y, Zhang F, Tuo Y, Ge R, Bai Z. Mitochondria in hypoxic pulmonary hypertension, roles and the potential targets. Front Physiol 2023; 14:1239643. [PMID: 37645564 PMCID: PMC10461481 DOI: 10.3389/fphys.2023.1239643] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/03/2023] [Indexed: 08/31/2023] Open
Abstract
Mitochondria are the centrol hub for cellular energy metabolisms. They regulate fuel metabolism by oxygen levels, participate in physiological signaling pathways, and act as oxygen sensors. Once oxygen deprived, the fuel utilizations can be switched from mitochondrial oxidative phosphorylation to glycolysis for ATP production. Notably, mitochondria can also adapt to hypoxia by making various functional and phenotypes changes to meet the demanding of oxygen levels. Hypoxic pulmonary hypertension is a life-threatening disease, but its exact pathgenesis mechanism is still unclear and there is no effective treatment available until now. Ample of evidence indicated that mitochondria play key factor in the development of hypoxic pulmonary hypertension. By hypoxia-inducible factors, multiple cells sense and transmit hypoxia signals, which then control the expression of various metabolic genes. This activation of hypoxia-inducible factors considered associations with crosstalk between hypoxia and altered mitochondrial metabolism, which plays an important role in the development of hypoxic pulmonary hypertension. Here, we review the molecular mechanisms of how hypoxia affects mitochondrial function, including mitochondrial biosynthesis, reactive oxygen homeostasis, and mitochondrial dynamics, to explore the potential of improving mitochondrial function as a strategy for treating hypoxic pulmonary hypertension.
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Affiliation(s)
- Yumei Geng
- Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Research Center for High Altitude Medicine, Qinghai University, Xining, China
- Department of Respiratory and Critical Care Medicine, Qinghai Provincial People’s Hospital, Xining, China
| | - Yu Hu
- Department of Pharmacy, Qinghai Provincial Traffic Hospital, Xining, China
| | - Fang Zhang
- Department of Respiratory and Critical Care Medicine, Qinghai Provincial People’s Hospital, Xining, China
| | - Yajun Tuo
- Department of Respiratory and Critical Care Medicine, Qinghai Provincial People’s Hospital, Xining, China
| | - Rili Ge
- Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Research Center for High Altitude Medicine, Qinghai University, Xining, China
| | - Zhenzhong Bai
- Key Laboratory of High Altitude Medicine (Ministry of Education), Key Laboratory of Application and Foundation for High Altitude Medicine Research in Qinghai Province (Qinghai-Utah Joint Research Key Lab for High Altitude Medicine), Research Center for High Altitude Medicine, Qinghai University, Xining, China
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3
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Moreno-Domínguez A, Colinas O, Smani T, Ureña J, López-Barneo J. Acute oxygen sensing by vascular smooth muscle cells. Front Physiol 2023; 14:1142354. [PMID: 36935756 PMCID: PMC10020353 DOI: 10.3389/fphys.2023.1142354] [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: 01/11/2023] [Accepted: 02/21/2023] [Indexed: 03/06/2023] Open
Abstract
An adequate supply of oxygen (O2) is essential for most life forms on earth, making the delivery of appropriate levels of O2 to tissues a fundamental physiological challenge. When O2 levels in the alveoli and/or blood are low, compensatory adaptive reflexes are produced that increase the uptake of O2 and its distribution to tissues within a few seconds. This paper analyzes the most important acute vasomotor responses to lack of O2 (hypoxia): hypoxic pulmonary vasoconstriction (HPV) and hypoxic vasodilation (HVD). HPV affects distal pulmonary (resistance) arteries, with its homeostatic role being to divert blood to well ventilated alveoli to thereby optimize the ventilation/perfusion ratio. HVD is produced in most systemic arteries, in particular in the skeletal muscle, coronary, and cerebral circulations, to increase blood supply to poorly oxygenated tissues. Although vasomotor responses to hypoxia are modulated by endothelial factors and autonomic innervation, it is well established that arterial smooth muscle cells contain an acute O2 sensing system capable of detecting changes in O2 tension and to signal membrane ion channels, which in turn regulate cytosolic Ca2+ levels and myocyte contraction. Here, we summarize current knowledge on the nature of O2 sensing and signaling systems underlying acute vasomotor responses to hypoxia. We also discuss similarities and differences existing in O2 sensors and effectors in the various arterial territories.
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Affiliation(s)
- Alejandro Moreno-Domínguez
- 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
| | - Olaia Colinas
- 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
| | - Tarik Smani
- 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
| | - Juan Ureña
- 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
| | - 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
- *Correspondence: José López-Barneo,
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Moral-Sanz J, Lewis SA, MacMillan S, Meloni M, McClafferty H, Viollet B, Foretz M, Del-Pozo J, Mark Evans A. AMPK deficiency in smooth muscles causes persistent pulmonary hypertension of the new-born and premature death. Nat Commun 2022; 13:5034. [PMID: 36028487 PMCID: PMC9418192 DOI: 10.1038/s41467-022-32568-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 08/05/2022] [Indexed: 11/10/2022] Open
Abstract
AMPK has been reported to facilitate hypoxic pulmonary vasoconstriction but, paradoxically, its deficiency precipitates pulmonary hypertension. Here we show that AMPK-α1/α2 deficiency in smooth muscles promotes persistent pulmonary hypertension of the new-born. Accordingly, dual AMPK-α1/α2 deletion in smooth muscles causes premature death of mice after birth, associated with increased muscularisation and remodeling throughout the pulmonary arterial tree, reduced alveolar numbers and alveolar membrane thickening, but with no oedema. Spectral Doppler ultrasound indicates pulmonary hypertension and attenuated hypoxic pulmonary vasoconstriction. Age-dependent right ventricular pressure elevation, dilation and reduced cardiac output was also evident. KV1.5 potassium currents of pulmonary arterial myocytes were markedly smaller under normoxia, which is known to facilitate pulmonary hypertension. Mitochondrial fragmentation and reactive oxygen species accumulation was also evident. Importantly, there was no evidence of systemic vasculopathy or hypertension in these mice. Moreover, hypoxic pulmonary vasoconstriction was attenuated by AMPK-α1 or AMPK-α2 deletion without triggering pulmonary hypertension.
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Affiliation(s)
- Javier Moral-Sanz
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Sophronia A Lewis
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Sandy MacMillan
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Marco Meloni
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Heather McClafferty
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | - Benoit Viollet
- Université Paris Cité, CNRS, INSERM, Institut Cochin, F-75014, Paris, France
| | - Marc Foretz
- Université Paris Cité, CNRS, INSERM, Institut Cochin, F-75014, Paris, France
| | - Jorge Del-Pozo
- R(D)SVS, University of Edinburgh Easter Bush Campus, EH25 9RG, Roslin, Edinburgh, UK
| | - A Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh, EH8 9XD, UK.
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5
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Flores K, Siques P, Brito J, Arribas SM. AMPK and the Challenge of Treating Hypoxic Pulmonary Hypertension. Int J Mol Sci 2022; 23:ijms23116205. [PMID: 35682884 PMCID: PMC9181235 DOI: 10.3390/ijms23116205] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 02/01/2023] Open
Abstract
Hypoxic pulmonary hypertension (HPH) is characterized by sustained elevation of pulmonary artery pressure produced by vasoconstriction and hyperproliferative remodeling of the pulmonary artery and subsequent right ventricular hypertrophy (RVH). The search for therapeutic targets for cardiovascular pathophysiology has extended in many directions. However, studies focused on mitigating high-altitude pulmonary hypertension (HAPH) have been rare. Because AMP-activated protein kinase (AMPK) is involved in cardiovascular and metabolic pathology, AMPK is often studied as a potential therapeutic target. AMPK is best characterized as a sensor of cellular energy that can also restore cellular metabolic homeostasis. However, AMPK has been implicated in other pathways with vasculoprotective effects. Notably, cellular metabolic stress increases the intracellular ADP/ATP or AMP/ATP ratio, and AMPK activation restores ATP levels by activating energy-producing catabolic pathways and inhibiting energy-consuming anabolic pathways, such as cell growth and proliferation pathways, promoting cardiovascular protection. Thus, AMPK activation plays an important role in antiproliferative, antihypertrophic and antioxidant pathways in the pulmonary artery in HPH. However, AMPK plays contradictory roles in promoting HPH development. This review describes the main findings related to AMPK participation in HPH and its potential as a therapeutic target. It also extrapolates known AMPK functions to discuss the less-studied HAPH context.
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Affiliation(s)
- Karen Flores
- Institute of Health Studies, University Arturo Prat, Av. Arturo Prat 2120, Iquique 1110939, Chile; (P.S.); (J.B.)
- Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and Its Health Sequelae, 20251 Hamburg, Germany and Iquique 1100000, Chile
- Correspondence: ; Tel.: +56-572526392
| | - Patricia Siques
- Institute of Health Studies, University Arturo Prat, Av. Arturo Prat 2120, Iquique 1110939, Chile; (P.S.); (J.B.)
- Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and Its Health Sequelae, 20251 Hamburg, Germany and Iquique 1100000, Chile
| | - Julio Brito
- Institute of Health Studies, University Arturo Prat, Av. Arturo Prat 2120, Iquique 1110939, Chile; (P.S.); (J.B.)
- Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and Its Health Sequelae, 20251 Hamburg, Germany and Iquique 1100000, Chile
| | - Silvia M. Arribas
- Department of Physiology, University Autonoma of Madrid, 28049 Madrid, Spain;
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6
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Identifying Potential Mitochondrial Proteome Signatures Associated with the Pathogenesis of Pulmonary Arterial Hypertension in the Rat Model. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:8401924. [PMID: 35237384 PMCID: PMC8885180 DOI: 10.1155/2022/8401924] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 01/12/2022] [Accepted: 02/05/2022] [Indexed: 01/09/2023]
Abstract
Pulmonary arterial hypertension (PAH) is a severe and progressive disease that affects the heart and lungs and a global health concern that impacts individuals and society. Studies have reported that some proteins related to mitochondrial metabolic functions could play an essential role in the pathogenesis of PAH, and their specific expression and biological function are still unclear. We successfully constructed a monocrotaline- (MCT-) induced PAH rat model in the present research. Then, the label-free quantification proteomic technique was used to determine mitochondrial proteins between the PAH group (n = 6) and the normal group (n = 6). Besides, we identified 1346 mitochondrial differentially expressed proteins (DEPs) between these two groups. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to analyze the mainly mitochondrial DEPs' biological functions and the signal pathways. Based on the protein-protein interaction (PPI) network construction and functional enrichment, we screened 19 upregulated mitochondrial genes (Psmd1, Psmc4, Psmd13, Psmc2, etc.) and 123 downregulated mitochondrial genes (Uqcrfs1, Uqcrc1, Atp5c1, Atp5a1, Uqcrc2, etc.) in rats with PAH. Furthermore, in an independent cohort dataset and experiments with rat lung tissue using qPCR, validation results consistently showed that 6 upregulated mitochondrial genes (Psmd2, Psmc4, Psmc3, Psmc5, Psmd13, and Psmc2) and 3 downregulated mitochondrial genes (Lipe, Cat, and Prkce) were significantly differentially expressed in the lung tissue of PAH rats. Using the RNAInter database, we predict potential miRNA target hub mitochondrial genes at the transcriptome level. We also identified bortezomib and carfilzomib as the potential drugs for treatment in PAH. Finally, this study provides us with a new perspective on critical biomarkers and treatment strategies in PAH.
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7
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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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8
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Dillard J, Meng X, Nelin L, Liu Y, Chen B. Nitric oxide activates AMPK by modulating PDE3A in human pulmonary artery smooth muscle cells. Physiol Rep 2021; 8:e14559. [PMID: 32914566 PMCID: PMC7507575 DOI: 10.14814/phy2.14559] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 01/17/2023] Open
Abstract
Phosphodiesterase 3 (PDE3), of which there are two isoforms, PDE3A and PDE3B, hydrolyzes cAMP and cGMP—cyclic nucleotides important in the regulation of pulmonary vascular tone. PDE3 has been implicated in pulmonary hypertension unresponsive to nitric oxide (NO); however, contributions of the two isoforms are not known. Furthermore, adenosine monophosphate‐activated protein kinase (AMPK), a critical regulator of cellular energy homeostasis, has been shown to be modulated by PDE3 in varying cell types. While AMPK has recently been implicated in pulmonary hypertension pathogenesis, its role and regulation in the pulmonary vasculature remain to be elucidated. Therefore, we utilized human pulmonary artery smooth muscle cells (hPASMC) to test the hypothesis that NO increases PDE3 expression in an isoform‐specific manner, thereby activating AMPK and inhibiting hPASMC proliferation. We found that in hPASMC, NO treatment increased PDE3A protein expression and PDE3 activity with a concomitant decrease in cAMP concentrations and increase in AMPK phosphorylation. Knockdown of PDE3A using siRNA transfection blunted the NO‐induced AMPK activation, indicating that PDE3A plays an important role in AMPK regulation in hPASMC. Treatment with a soluble guanylate cyclase (sGC) stimulator increased PDE3A expression and AMPK activation similar to that seen with NO treatment, whereas treatment with a sGC inhibitor blunted the NO‐induced increase in PDE3A and AMPK activation. These results suggest that NO increases PDE3A expression, decreases cAMP, and activates AMPK via the sGC‐cGMP pathway. We speculate that NO‐induced increases in PDE3A and AMPK may have implications in the pathogenesis and the response to therapies in pulmonary hypertensive disorders.
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Affiliation(s)
- Julie Dillard
- Pulmonary Hypertension Group, Center for Perinatal Research, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Xiaomei Meng
- Pulmonary Hypertension Group, Center for Perinatal Research, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Leif Nelin
- Pulmonary Hypertension Group, Center for Perinatal Research, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Yusen Liu
- Pulmonary Hypertension Group, Center for Perinatal Research, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Bernadette Chen
- Pulmonary Hypertension Group, Center for Perinatal Research, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
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9
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Zhao Q, Song P, Zou MH. AMPK and Pulmonary Hypertension: Crossroads Between Vasoconstriction and Vascular Remodeling. Front Cell Dev Biol 2021; 9:691585. [PMID: 34169079 PMCID: PMC8217619 DOI: 10.3389/fcell.2021.691585] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022] Open
Abstract
Pulmonary hypertension (PH) is a debilitating and life-threatening disease characterized by increased blood pressure within the pulmonary arteries. Adenosine monophosphate-activated protein kinase (AMPK) is a heterotrimeric serine-threonine kinase that contributes to the regulation of metabolic and redox signaling pathways. It has key roles in the regulation of cell survival and proliferation. The role of AMPK in PH is controversial because both inhibition and activation of AMPK are preventive against PH development. Some clinical studies found that metformin, the first-line antidiabetic drug and the canonical AMPK activator, has therapeutic efficacy during treatment of early-stage PH. Other study findings suggest the use of metformin is preferentially beneficial for treatment of PH associated with heart failure with preserved ejection fraction (PH-HFpEF). In this review, we discuss the "AMPK paradox" and highlight the differential effects of AMPK on pulmonary vasoconstriction and pulmonary vascular remodeling. We also review the effects of AMPK activators and inhibitors on rescue of preexisting PH in animals and include a discussion of gender differences in the response to metformin in PH.
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Affiliation(s)
| | | | - Ming-Hui Zou
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
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10
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Coburn RF. Coronary and cerebral metabolism-blood flow coupling and pulmonary alveolar ventilation-blood flow coupling may be disabled during acute carbon monoxide poisoning. J Appl Physiol (1985) 2020; 129:1039-1050. [PMID: 32853110 DOI: 10.1152/japplphysiol.00172.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Current evidence indicates that the toxicity of carbon monoxide (CO) poisoning results from increases in reactive oxygen species (ROS) generation plus tissue hypoxia resulting from decreases in capillary Po2 evoked by effects of increases in blood [carboxyhemoglobin] on the oxyhemoglobin dissociation curve. There has not been consideration of how increases in Pco could influence metabolism-blood flow coupling, a physiological mechanism that regulates the uniformity of tissue Po2, and alveolar ventilation-blood flow coupling, a mechanism that increases the efficiency of pulmonary O2 uptake. Using published data, I consider hypotheses that these coupling mechanisms, triggered by O2 and CO sensors located in arterial and arteriolar vessels in the coronary and cerebral circulations and in lung intralobar arteries, are disrupted during acute CO poisoning. These hypotheses are supported by calculations that show that the Pco in these vessels can reach levels during CO poisoning that would exert effects on signal transduction molecules involved in these coupling mechanisms.NEW & NOTEWORTHY This article introduces and supports a postulate that the tissue hypoxia component of carbon monoxide poisoning results in part from impairment of physiological adaptation mechanisms whereby tissues can match regional blood flow to O2 uptake, and the lung can match regional blood flow to alveolar ventilation.
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Affiliation(s)
- Ronald F Coburn
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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11
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Evans AM. On a Magical Mystery Tour with 8-Bromo-Cyclic ADP-Ribose: From All-or-None Block to Nanojunctions and the Cell-Wide Web. Molecules 2020; 25:E4768. [PMID: 33081414 PMCID: PMC7587525 DOI: 10.3390/molecules25204768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/08/2020] [Indexed: 11/16/2022] Open
Abstract
A plethora of cellular functions are controlled by calcium signals, that are greatly coordinated by calcium release from intracellular stores, the principal component of which is the sarco/endooplasmic reticulum (S/ER). In 1997 it was generally accepted that activation of various G protein-coupled receptors facilitated inositol-1,4,5-trisphosphate (IP3) production, activation of IP3 receptors and thus calcium release from S/ER. Adding to this, it was evident that S/ER resident ryanodine receptors (RyRs) could support two opposing cellular functions by delivering either highly localised calcium signals, such as calcium sparks, or by carrying propagating, global calcium waves. Coincidentally, it was reported that RyRs in mammalian cardiac myocytes might be regulated by a novel calcium mobilising messenger, cyclic adenosine diphosphate-ribose (cADPR), that had recently been discovered by HC Lee in sea urchin eggs. A reputedly selective and competitive cADPR antagonist, 8-bromo-cADPR, had been developed and was made available to us. We used 8-bromo-cADPR to further explore our observation that S/ER calcium release via RyRs could mediate two opposing functions, namely pulmonary artery dilation and constriction, in a manner seemingly independent of IP3Rs or calcium influx pathways. Importantly, the work of others had shown that, unlike skeletal and cardiac muscles, smooth muscles might express all three RyR subtypes. If this were the case in our experimental system and cADPR played a role, then 8-bromo-cADPR would surely block one of the opposing RyR-dependent functions identified, or the other, but certainly not both. The latter seemingly implausible scenario was confirmed. How could this be, do cells hold multiple, segregated SR stores that incorporate different RyR subtypes in receipt of spatially segregated signals carried by cADPR? The pharmacological profile of 8-bromo-cADPR action supported not only this, but also indicated that intracellular calcium signals were delivered across intracellular junctions formed by the S/ER. Not just one, at least two. This article retraces the steps along this journey, from the curious pharmacological profile of 8-bromo-cADPR to the discovery of the cell-wide web, a diverse network of cytoplasmic nanocourses demarcated by S/ER nanojunctions, which direct site-specific calcium flux and may thus coordinate the full panoply of cellular processes.
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Grants
- 01/A/S/07453 Biotechnology and Biological Sciences Research Council
- WT046374 , WT056423, WT070772, WT074434, WT081195AIA, WT212923, WT093147 Wellcome Trust
- PG/10/95/28657 British Heart Foundation
- FS/03/033/15432, FS/05/050, PG/05/128/19884, RG/12/14/29885, PG/10/95/28657 British Heart Foundation
- RG/12/14/29885 British Heart Foundation
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Affiliation(s)
- A Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, Edinburgh Medical School, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
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12
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Kun L, Lu L, Yongda L, Xingyue L, Guang H. Hyperbaric oxygen promotes mitophagy by activating CaMKK β/AMPK signal pathway in rats of neuropathic pain. Mol Pain 2020; 15:1744806919871381. [PMID: 31382832 PMCID: PMC6710678 DOI: 10.1177/1744806919871381] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Liu Kun
- 1 Department of Anesthesiology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Li Lu
- 1 Department of Anesthesiology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Liu Yongda
- 1 Department of Anesthesiology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Li Xingyue
- 1 Department of Anesthesiology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Han Guang
- 1 Department of Anesthesiology, Shengjing Hospital, China Medical University, Shenyang, China
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13
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Evans AM, Hardie DG. AMPK and the Need to Breathe and Feed: What's the Matter with Oxygen? Int J Mol Sci 2020; 21:ijms21103518. [PMID: 32429235 PMCID: PMC7279029 DOI: 10.3390/ijms21103518] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/12/2022] Open
Abstract
We live and to do so we must breathe and eat, so are we a combination of what we eat and breathe? Here, we will consider this question, and the role in this respect of the AMP-activated protein kinase (AMPK). Emerging evidence suggests that AMPK facilitates central and peripheral reflexes that coordinate breathing and oxygen supply, and contributes to the central regulation of feeding and food choice. We propose, therefore, that oxygen supply to the body is aligned with not only the quantity we eat, but also nutrient-based diet selection, and that the cell-specific expression pattern of AMPK subunit isoforms is critical to appropriate system alignment in this respect. Currently available information on how oxygen supply may be aligned with feeding and food choice, or vice versa, through our motivation to breathe and select particular nutrients is sparse, fragmented and lacks any integrated understanding. By addressing this, we aim to provide the foundations for a clinical perspective that reveals untapped potential, by highlighting how aberrant cell-specific changes in the expression of AMPK subunit isoforms could give rise, in part, to known associations between metabolic disease, such as obesity and type 2 diabetes, sleep-disordered breathing, pulmonary hypertension and acute respiratory distress syndrome.
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Affiliation(s)
- A. Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, Edinburgh Medical School, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
- Correspondence:
| | - D. Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK;
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14
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Weise-Cross L, Resta TC, Jernigan NL. Redox Regulation of Ion Channels and Receptors in Pulmonary Hypertension. Antioxid Redox Signal 2019; 31:898-915. [PMID: 30569735 PMCID: PMC7061297 DOI: 10.1089/ars.2018.7699] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 12/11/2018] [Indexed: 02/06/2023]
Abstract
Significance: Pulmonary hypertension (PH) is characterized by elevated vascular resistance due to vasoconstriction and remodeling of the normally low-pressure pulmonary vasculature. Redox stress contributes to the pathophysiology of this disease by altering the regulation and activity of membrane receptors, K+ channels, and intracellular Ca2+ homeostasis. Recent Advances: Antioxidant therapies have had limited success in treating PH, leading to a growing appreciation that reductive stress, in addition to oxidative stress, plays a role in metabolic and cell signaling dysfunction in pulmonary vascular cells. Reactive oxygen species generation from mitochondria and NADPH oxidases has substantial effects on K+ conductance and membrane potential, and both receptor-operated and store-operated Ca2+ entry. Critical Issues: Some specific redox changes resulting from oxidation, S-nitrosylation, and S-glutathionylation are known to modulate membrane receptor and ion channel activity in PH. However, many sites of regulation that have been elucidated in nonpulmonary cell types have not been tested in the pulmonary vasculature, and context-specific molecular mechanisms are lacking. Future Directions: Here, we review what is known about redox regulation of membrane receptors and ion channels in PH. Further investigation of the mechanisms involved is needed to better understand the etiology of PH and develop better targeted treatment strategies.
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Affiliation(s)
- Laura Weise-Cross
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C. Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L. Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
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15
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Fujii N, McGarr GW, Ichinose M, Nishiyasu T, Kenny GP. Tetraethylammonium, glibenclamide, and 4‐aminopyridine modulate post‐occlusive reactive hyperemia in non‐glabrous human skin with no roles of
NOS
and
COX. Microcirculation 2019; 27:e12586. [DOI: 10.1111/micc.12586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 07/25/2019] [Accepted: 08/18/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Naoto Fujii
- Faculty of Health and Sport Sciences University of Tsukuba Tsukuba City Japan
| | - Gregory W. McGarr
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa ON Canada
| | - Masashi Ichinose
- Human Integrative Physiology Laboratory School of Business Administration Meiji University Tokyo Japan
| | - Takeshi Nishiyasu
- Faculty of Health and Sport Sciences University of Tsukuba Tsukuba City Japan
| | - Glen P. Kenny
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa ON Canada
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16
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Mercurio V, Bianco A, Campi G, Cuomo A, Diab N, Mancini A, Parrella P, Petretta M, Hassoun PM, Bonaduce D. New Drugs, Therapeutic Strategies, and Future Direction for the Treatment of Pulmonary Arterial Hypertension. Curr Med Chem 2019; 26:2844-2864. [DOI: 10.2174/0929867325666180201095743] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/21/2017] [Accepted: 12/21/2017] [Indexed: 12/20/2022]
Abstract
Despite recent advances in Pulmonary Arterial Hypertension (PAH) treatment, this condition is still characterized by an extremely poor prognosis. In this review, we discuss the use of newly-approved drugs for PAH treatment with already known mechanisms of action (macitentan), innovative targets (riociguat and selexipag), and novel therapeutic approaches with initial up-front combination therapy. Secondly, we describe new potential signaling pathways and investigational drugs with promising role in the treatment of PAH.
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Affiliation(s)
- Valentina Mercurio
- Federico II University, Department of Translational Medical Sciences, Naples, Italy
| | - Anna Bianco
- Federico II University, Department of Translational Medical Sciences, Naples, Italy
| | - Giacomo Campi
- Federico II University, Department of Translational Medical Sciences, Naples, Italy
| | - Alessandra Cuomo
- Federico II University, Department of Translational Medical Sciences, Naples, Italy
| | - Nermin Diab
- University of Ottawa, Department of Medicine, Ottawa, ON, Canada
| | - Angela Mancini
- Federico II University, Department of Translational Medical Sciences, Naples, Italy
| | - Paolo Parrella
- Federico II University, Department of Translational Medical Sciences, Naples, Italy
| | - Mario Petretta
- Federico II University, Department of Translational Medical Sciences, Naples, Italy
| | - Paul M. Hassoun
- Johns Hopkins University, Division of Pulmonary and Critical Care Medicine, Baltimore, MD, United States
| | - Domenico Bonaduce
- Federico II University, Department of Translational Medical Sciences, Naples, Italy
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17
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AMPK breathing and oxygen supply. Respir Physiol Neurobiol 2019; 265:112-120. [DOI: 10.1016/j.resp.2018.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 08/06/2018] [Accepted: 08/31/2018] [Indexed: 01/28/2023]
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18
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Moral-Sanz J, Lewis SA, MacMillan S, Ross FA, Thomson A, Viollet B, Foretz M, Moran C, Hardie DG, Evans AM. The LKB1-AMPK-α1 signaling pathway triggers hypoxic pulmonary vasoconstriction downstream of mitochondria. Sci Signal 2018; 11:11/550/eaau0296. [PMID: 30279167 DOI: 10.1126/scisignal.aau0296] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Hypoxic pulmonary vasoconstriction (HPV), which aids ventilation-perfusion matching in the lungs, is triggered by mechanisms intrinsic to pulmonary arterial smooth muscles. The unique sensitivity of these muscles to hypoxia is conferred by mitochondrial cytochrome c oxidase subunit 4 isoform 2, the inhibition of which has been proposed to trigger HPV through increased generation of mitochondrial reactive oxygen species. Contrary to this model, we have shown that the LKB1-AMPK-α1 signaling pathway is critical to HPV. Spectral Doppler ultrasound revealed that deletion of the AMPK-α1 catalytic subunit blocked HPV in mice during mild (8% O2) and severe (5% O2) hypoxia, whereas AMPK-α2 deletion attenuated HPV only during severe hypoxia. By contrast, neither of these genetic manipulations affected serotonin-induced reductions in pulmonary vascular flow. HPV was also attenuated by reduced expression of LKB1, a kinase that activates AMPK during energy stress, but not after deletion of CaMKK2, a kinase that activates AMPK in response to increases in cytoplasmic Ca2+ Fluorescence imaging of acutely isolated pulmonary arterial myocytes revealed that AMPK-α1 or AMPK-α2 deletion did not affect mitochondrial membrane potential during normoxia or hypoxia. However, deletion of AMPK-α1, but not of AMPK-α2, blocked hypoxia from inhibiting KV1.5, the classical "oxygen-sensing" K+ channel in pulmonary arterial myocytes. We conclude that LKB1-AMPK-α1 signaling pathways downstream of mitochondria are critical for the induction of HPV, in a manner also supported by AMPK-α2 during severe hypoxia.
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Affiliation(s)
- Javier Moral-Sanz
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Sophronia A Lewis
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Sandy MacMillan
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Fiona A Ross
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Adrian Thomson
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Benoit Viollet
- Institut Cochin, INSERM U1016, Sorbonne Paris cité, 75014 Paris, France.,CNRS UMR 8104, Sorbonne Paris cité, 75014 Paris, France.,Université Paris Descartes, Sorbonne Paris cité, 75014 Paris, France
| | - Marc Foretz
- Institut Cochin, INSERM U1016, Sorbonne Paris cité, 75014 Paris, France.,CNRS UMR 8104, Sorbonne Paris cité, 75014 Paris, France.,Université Paris Descartes, Sorbonne Paris cité, 75014 Paris, France
| | - Carmel Moran
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - D Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - A Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK.
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19
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Lee H, Kim KC, Hong YM. Change of voltage-gated potassium channel 1.7 expressions in monocrotaline-induced pulmonary arterial hypertension rat model. KOREAN JOURNAL OF PEDIATRICS 2018; 61:271-278. [PMID: 30274504 PMCID: PMC6172520 DOI: 10.3345/kjp.2018.06457] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 06/01/2018] [Indexed: 11/27/2022]
Abstract
Purpose Abnormal potassium channels expression affects vessel function, including vascular tone and proliferation rate. Diverse potassium channels, including voltage-gated potassium (Kv) channels, are involved in pathological changes of pulmonary arterial hypertension (PAH). Since the role of the Kv1.7 channel in PAH has not been previously studied, we investigated whether Kv1.7 channel expression changes in the lung tissue of a monocrotaline (MCT)-induced PAH rat model and whether this change is influenced by the endothelin (ET)-1 and reactive oxygen species (ROS) pathways. Methods Rats were separated into 2 groups: the control (C) group and the MCT (M) group (60 mg/kg MCT). A hemodynamic study was performed by catheterization into the external jugular vein to estimate the right ventricular pressure (RVP), and pathological changes in the lung tissue were investigated. Changes in protein and mRNA levels were confirmed by western blot and polymerase chain reaction analysis, respectively. Results MCT caused increased RVP, medial wall thickening of the pulmonary arterioles, and increased expression level of ET-1, ET receptor A, and NADPH oxidase (NOX) 4 proteins. Decreased Kv1.7 channel expression was detected in the lung tissue. Inward-rectifier channel 6.1 expression in the lung tissue also increased. We confirmed that ET-1 increased NOX4 level and decreased glutathione peroxidase-1 level in pulmonary artery smooth muscle cells (PASMCs). ET-1 increased ROS level in PASMCs. Conclusion Decreased Kv1.7 channel expression might be caused by the ET-1 and ROS pathways and contributes to MCT-induced PAH.
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Affiliation(s)
- Hyeryon Lee
- Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea
| | - Kwan Chang Kim
- Department of Thoracic and Cardiovascular Surgery, Ewha Womans University School of Medicine, Seoul, Korea
| | - Young Mi Hong
- Department of Pediatrics, Ewha Womans University School of Medicine, Seoul, Korea
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20
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MacMillan S, Evans AM. AMPK-α1 or AMPK-α2 Deletion in Smooth Muscles Does Not Affect the Hypoxic Ventilatory Response or Systemic Arterial Blood Pressure Regulation During Hypoxia. Front Physiol 2018; 9:655. [PMID: 29928235 PMCID: PMC5997817 DOI: 10.3389/fphys.2018.00655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/14/2018] [Indexed: 12/31/2022] Open
Abstract
The hypoxic ventilatory response (HVR) is markedly attenuated by AMPK-α1 deletion conditional on the expression of Cre-recombinase in tyrosine hydroxylase (TH) expressing cells, precipitating marked increases in apnea frequency and duration. It was concluded that ventilatory dysfunction caused by AMPK deficiency was driven by neurogenic mechanisms. However, TH is transiently expressed in other cell types during development, and it is evident that central respiratory depression can also be triggered by myogenic mechanisms that impact blood supply to the brain. We therefore assessed the effect on the HVR and systemic arterial blood pressure of AMPK deletion in vascular smooth muscles. There was no difference in minute ventilation during normoxia. However, increases in minute ventilation during severe hypoxia (8% O2) were, if affected at all, augmented by AMPK-α1 and AMPK-α2 deletion in smooth muscles; despite the fact that hypoxia (8% O2) evoked falls in arterial SpO2 comparable with controls. Surprisingly, these mice exhibited no difference in systolic, diastolic or mean arterial blood pressure during normoxia or hypoxia. We conclude that neither AMPK-α1 nor AMPK-α2 are required in smooth muscle for the regulation of systemic arterial blood pressure during hypoxia, and that AMPK-α1 deficiency does not impact the HVR by myogenic mechanisms.
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Affiliation(s)
- Sandy MacMillan
- Centre for Discovery Brain Sciences and Centre for Cardiovascular Science, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - A Mark Evans
- Centre for Discovery Brain Sciences and Centre for Cardiovascular Science, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
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21
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Strielkov I, Pak O, Sommer N, Weissmann N. Recent advances in oxygen sensing and signal transduction in hypoxic pulmonary vasoconstriction. J Appl Physiol (1985) 2017; 123:1647-1656. [PMID: 28751366 DOI: 10.1152/japplphysiol.00103.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a physiological reaction, which adapts lung perfusion to regional ventilation and optimizes gas exchange. Impaired HPV may cause systemic hypoxemia, while generalized HPV contributes to the development of pulmonary hypertension. The triggering mechanisms underlying HPV are still not fully elucidated. Several hypotheses are currently under debate, including a possible decrease as well as an increase in reactive oxygen species as a triggering event. Recent findings suggest an increase in the production of reactive oxygen species in pulmonary artery smooth muscle cells by complex III of the mitochondrial electron transport chain and occurrence of oxygen sensing at complex IV. Other essential components are voltage-dependent potassium and possibly L-type, transient receptor potential channel 6, and transient receptor potential vanilloid 4 channels. The release of arachidonic acid metabolites appears also to be involved in HPV regulation. Further investigation of the HPV mechanisms will facilitate the development of novel therapeutic strategies for the treatment of HPV-related disorders.
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Affiliation(s)
- Ievgen Strielkov
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Oleg Pak
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Natasha Sommer
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
| | - Norbert Weissmann
- Excellence Cluster Cardiopulmonary System, University of Giessen Lung Center, German Center for Lung Research (DZL), Justus-Liebig-University, Giessen , Germany
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22
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Abstract
The AMP-activated protein kinase (AMPK) is a key regulator of cellular and whole-body energy homeostasis, which acts to restore energy homoeostasis whenever cellular energy charge is depleted. Over the last 2 decades, it has become apparent that AMPK regulates several other cellular functions and has specific roles in cardiovascular tissues, acting to regulate cardiac metabolism and contractile function, as well as promoting anticontractile, anti-inflammatory, and antiatherogenic actions in blood vessels. In this review, we discuss the role of AMPK in the cardiovascular system, including the molecular basis of mutations in AMPK that alter cardiac physiology and the proposed mechanisms by which AMPK regulates vascular function under physiological and pathophysiological conditions.
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Affiliation(s)
- Ian P Salt
- From the Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Scotland, United Kingdom (I.P.S.); and Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, United Kingdom (D.G.H.).
| | - D Grahame Hardie
- From the Institute of Cardiovascular & Medical Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Scotland, United Kingdom (I.P.S.); and Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, United Kingdom (D.G.H.)
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23
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Harvey LD, Chan SY. Emerging Metabolic Therapies in Pulmonary Arterial Hypertension. J Clin Med 2017; 6:jcm6040043. [PMID: 28375184 PMCID: PMC5406775 DOI: 10.3390/jcm6040043] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 03/28/2017] [Accepted: 03/29/2017] [Indexed: 12/26/2022] Open
Abstract
Pulmonary hypertension (PH) is an enigmatic vascular disorder characterized by pulmonary vascular remodeling and increased pulmonary vascular resistance, ultimately resulting in pressure overload, dysfunction, and failure of the right ventricle. Current medications for PH do not reverse or prevent disease progression, and current diagnostic strategies are suboptimal for detecting early-stage disease. Thus, there is a substantial need to develop new diagnostics and therapies that target the molecular origins of PH. Emerging investigations have defined metabolic aberrations as fundamental and early components of disease manifestation in both pulmonary vasculature and the right ventricle. As such, the elucidation of metabolic dysregulation in pulmonary hypertension allows for greater therapeutic insight into preventing, halting, or even reversing disease progression. This review will aim to discuss (1) the reprogramming and dysregulation of metabolic pathways in pulmonary hypertension; (2) the emerging therapeutic interventions targeting these metabolic pathways; and (3) further innovation needed to overcome barriers in the treatment of this devastating disease.
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Affiliation(s)
- Lloyd D Harvey
- Medical Scientist Training Program, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.
| | - Stephen Y Chan
- Division of Cardiology, Center for Pulmonary Vascular Biology and Medicine, Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.
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