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D'Addario CA, Matsumura S, Kitagawa A, Lainer GM, Zhang F, D'silva M, Khan MY, Froogh G, Gruzdev A, Zeldin DC, Schwartzman ML, Gupte SA. Global and endothelial G-protein coupled receptor 75 (GPR75) knockout relaxes pulmonary artery and mitigates hypoxia-induced pulmonary hypertension. Vascul Pharmacol 2023; 153:107235. [PMID: 37742819 PMCID: PMC10841449 DOI: 10.1016/j.vph.2023.107235] [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: 10/11/2022] [Revised: 09/04/2023] [Accepted: 09/21/2023] [Indexed: 09/26/2023]
Abstract
RATIONALE Pulmonary hypertension (PH) is a multifactorial disease with a poor prognosis and inadequate treatment options. We found two-fold higher expression of the orphan G-Protein Coupled Receptor 75 (GPR75) in leukocytes and pulmonary arterial smooth muscle cells from idiopathic PH patients and from lungs of C57BL/6 mice exposed to hypoxia. We therefore postulated that GPR75 signaling is critical to the pathogenesis of PH. METHODS To test this hypothesis, we exposed global (Gpr75-/-) and endothelial cell (EC) GPR75 knockout (EC-Gpr75-/-) mice and wild-type (control) mice to hypoxia (10% oxygen) or normal atmospheric oxygen for 5 weeks. We then recorded echocardiograms and performed right heart catheterizations. RESULTS Chronic hypoxia increased right ventricular systolic and diastolic pressures in wild-type mice but not Gpr75-/- or EC-Gpr75-/- mice. In situ hybridization and qPCR results revealed that Gpr75 expression was increased in the alveoli, airways and pulmonary arteries of mice exposed to hypoxia. In addition, levels of chemokine (CC motif) ligand 5 (CCL5), a low affinity ligand of GPR75, were increased in the lungs of wild-type, but not Gpr75-/-, mice exposed to hypoxia, and CCL5 enhanced hypoxia-induced contraction of intra-lobar pulmonary arteries in a GPR75-dependent manner. Gpr75 knockout also increased pulmonary cAMP levels and decreased contraction of intra-lobar pulmonary arteries evoked by endothelin-1 or U46619 in cAMP-protein kinase A-dependent manner. CONCLUSION These results suggest GPR75 has a significant role in the development of hypoxia-induced PH.
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Affiliation(s)
| | - Shun Matsumura
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA
| | - Atsushi Kitagawa
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA
| | - Gregg M Lainer
- Department of Cardiology, and Heart and Vascular Institute, Westchester Medical Center and New York Medical College, Valhalla, NY 10595, USA
| | - Frank Zhang
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA
| | - Melinee D'silva
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA
| | - Mohammad Y Khan
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA
| | - Ghezal Froogh
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA
| | - Artiom Gruzdev
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Darryl C Zeldin
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | | | - Sachin A Gupte
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA.
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Pakhomov NV, Kostyunina DS, Macori G, Dillon E, Brady T, Sundaramoorthy G, Connolly C, Blanco A, Fanning S, Brennan L, McLoughlin P, Baugh JA. High-Soluble-Fiber Diet Attenuates Hypoxia-Induced Vascular Remodeling and the Development of Hypoxic Pulmonary Hypertension. Hypertension 2023; 80:2372-2385. [PMID: 37851762 DOI: 10.1161/hypertensionaha.123.20914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/10/2023] [Indexed: 10/20/2023]
Abstract
BACKGROUND Hypoxic pulmonary hypertension is a difficult disease to manage that is characterized by sustained elevation of pulmonary vascular resistance and pulmonary artery pressure due to vasoconstriction, perivascular inflammation, and vascular remodeling. Consumption of soluble-fiber is associated with lower systemic blood pressure, but little is known about its ability to affect the pulmonary circulation. METHODS Mice were fed either a low- or high-soluble-fiber diet (0% or 16.9% inulin) and then exposed to hypoxia (FiO2, 0.10) for 21 days to induce pulmonary hypertension. The impact of diet on right ventricular systolic pressure and pulmonary vascular resistance was determined in vivo or in ex vivo isolated lungs, respectively, and correlated with alterations in the composition of the gut microbiome, plasma metabolome, pulmonary inflammatory cell phenotype, and lung proteome. RESULTS High-soluble-fiber diet increased the abundance of short-chain fatty acid-producing bacteria, with parallel increases in plasma propionate levels, and reduced the abundance of disease-related bacterial genera such as Staphylococcus, Clostridioides, and Streptococcus in hypoxic mice with parallel decreases in plasma levels of p-cresol sulfate. High-soluble-fiber diet decreased hypoxia-induced elevations of right ventricular systolic pressure and pulmonary vascular resistance. These changes were associated with reduced proportions of interstitial macrophages, dendritic cells, and nonclassical monocytes. Whole-lung proteomics revealed proteins and molecular pathways that may explain the effect of soluble-fiber supplementation. CONCLUSIONS This study demonstrates for the first time that a high-soluble-fiber diet attenuates hypoxia-induced pulmonary vascular remodeling and the development of pulmonary hypertension in a mouse model of hypoxic pulmonary hypertension and highlights diet-derived metabolites that may have an immuno-modulatory role in the lung.
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Affiliation(s)
- Nikolai V Pakhomov
- School of Medicine, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (N.V.P., D.S.K., T.B., P.M., J.A.B.)
| | - Daria S Kostyunina
- School of Medicine, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (N.V.P., D.S.K., T.B., P.M., J.A.B.)
| | - Guerrino Macori
- School of Public Health, Physiotherapy & Sports Science, University College Dublin, Ireland (G.M., S.F.)
| | - Eugene Dillon
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (E.D., A.B.)
| | - Tara Brady
- School of Medicine, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (N.V.P., D.S.K., T.B., P.M., J.A.B.)
| | - Geetha Sundaramoorthy
- School of Agriculture and Food Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (G.S., C.C., L.B.)
| | - Claire Connolly
- School of Agriculture and Food Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (G.S., C.C., L.B.)
| | - Alfonso Blanco
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (E.D., A.B.)
| | - Séamus Fanning
- School of Public Health, Physiotherapy & Sports Science, University College Dublin, Ireland (G.M., S.F.)
| | - Lorraine Brennan
- School of Agriculture and Food Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (G.S., C.C., L.B.)
| | - Paul McLoughlin
- School of Medicine, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (N.V.P., D.S.K., T.B., P.M., J.A.B.)
| | - John A Baugh
- School of Medicine, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland (N.V.P., D.S.K., T.B., P.M., J.A.B.)
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Wang YX, Reyes-García J, Di Mise A, Zheng YM. Role of ryanodine receptor 2 and FK506-binding protein 12.6 dissociation in pulmonary hypertension. J Gen Physiol 2023; 155:213798. [PMID: 36625865 PMCID: PMC9836826 DOI: 10.1085/jgp.202213100] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 07/29/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
Pulmonary hypertension (PH) is a devastating disease characterized by a progressive increase in pulmonary arterial pressure leading to right ventricular failure and death. A major cellular response in this disease is the contraction of smooth muscle cells (SMCs) of the pulmonary vasculature. Cell contraction is determined by the increase in intracellular Ca2+ concentration ([Ca2+]i), which is generated and regulated by various ion channels. Several studies by us and others have shown that ryanodine receptor 2 (RyR2), a Ca2+-releasing channel in the sarcoplasmic reticulum (SR), is an essential ion channel for the control of [Ca2+]i in pulmonary artery SMCs (PASMCs), thereby mediating the sustained vasoconstriction seen in PH. FK506-binding protein 12.6 (FKBP12.6) strongly associates with RyR2 to stabilize its functional activity. FKBP12.6 can be dissociated from RyR2 by a hypoxic stimulus to increase channel function and Ca2+ release, leading to pulmonary vasoconstriction and PH. More specifically, dissociation of the RyR2-FKBP12.6 complex is a consequence of increased mitochondrial ROS generation mediated by the Rieske iron-sulfur protein (RISP) at the mitochondrial complex III after hypoxia. Overall, RyR2/FKBP12.6 dissociation and the corresponding signaling pathway may be an important factor in the development of PH. Novel drugs and biologics targeting RyR2, FKBP12.6, and related molecules may become unique effective therapeutics for PH.
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Affiliation(s)
- Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Correspondence to Yong-Xiao Wang:
| | - Jorge Reyes-García
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México,Ciudad de México, México
| | - Annarita Di Mise
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Yun-Min Zheng:
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Piezo1 Channel Activation Reverses Pulmonary Artery Vasoconstriction in an Early Rat Model of Pulmonary Hypertension: The Role of Ca2+ Influx and Akt-eNOS Pathway. Cells 2022; 11:cells11152349. [PMID: 35954193 PMCID: PMC9367624 DOI: 10.3390/cells11152349] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/18/2022] [Accepted: 07/26/2022] [Indexed: 02/05/2023] Open
Abstract
In intrapulmonary arteries (IPAs), mechanical forces due to blood flow control vessel tone, and these forces change during pulmonary hypertension (PH). Piezo1, a stretch-activated calcium channel, is a sensor of mechanical stress present in both endothelial cells (ECs) and smooth muscle cells (SMCs). The present study investigated the role of Piezo1 on IPA in the chronic hypoxia model of PH. Rats were raised in chronically hypoxic conditions for 1 (1W-CH, early stage) or 3 weeks (3W-CH, late-stage) of PH or in normoxic conditions (Nx). Immunofluorescence labeling and patch-clamping revealed the presence of Piezo1 in both ECs and SMCs. The Piezo1 agonist, Yoda1, induced an IPA contraction in Nx and 3W-CH. Conversely, Yoda1 induced an endothelial nitric oxide (eNOS) dependent relaxation in 1W-CH. In ECs, the Yoda1-mediated intracellular calcium concentration ([Ca2+]i) increase was greater in 1W-CH as compared to Nx. Yoda1 induced an EC hyperpolarization in 1W-CH. The eNOS levels were increased in 1W-CH IPA compared to Nx or 3W-CH PH and Yoda1 activated phosphorylation of Akt (Ser473) and eNOS (Ser1177). Thus, we demonstrated that endothelial Piezo1 contributes to intrapulmonary vascular relaxation by controlling endothelial [Ca2+]i, endothelial-dependent hyperpolarization, and Akt-eNOS pathway activation in the early stage of PH.
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Barnes LA, Mesarwi OA, Sanchez-Azofra A. The Cardiovascular and Metabolic Effects of Chronic Hypoxia in Animal Models: A Mini-Review. Front Physiol 2022; 13:873522. [PMID: 35432002 PMCID: PMC9008331 DOI: 10.3389/fphys.2022.873522] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Animal models are useful to understand the myriad physiological effects of hypoxia. Such models attempt to recapitulate the hypoxemia of human disease in various ways. In this mini-review, we consider the various animal models which have been deployed to understand the effects of chronic hypoxia on pulmonary and systemic blood pressure, glucose and lipid metabolism, atherosclerosis, and stroke. Chronic sustained hypoxia (CSH)-a model of chronic lung or heart diseases in which hypoxemia may be longstanding and persistent, or of high altitude, in which effective atmospheric oxygen concentration is low-reliably induces pulmonary hypertension in rodents, and appears to have protective effects on glucose metabolism. Chronic intermittent hypoxia (CIH) has long been used as a model of obstructive sleep apnea (OSA), in which recurrent airway occlusion results in intermittent reductions in oxyhemoglobin saturations throughout the night. CIH was first shown to increase systemic blood pressure, but has also been associated with other maladaptive physiological changes, including glucose dysregulation, atherosclerosis, progression of nonalcoholic fatty liver disease, and endothelial dysfunction. However, models of CIH have generally been implemented so as to mimic severe human OSA, with comparatively less focus on milder hypoxic regimens. Here we discuss CSH and CIH conceptually, the effects of these stimuli, and limitations of the available data.
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Affiliation(s)
- Laura A. Barnes
- Division of Pulmonary, Critical Care, and Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Omar A. Mesarwi
- Division of Pulmonary, Critical Care, and Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Ana Sanchez-Azofra
- Division of Pulmonary, Critical Care, and Sleep Medicine and Physiology, Department of Medicine, University of California, San Diego, San Diego, CA, United States
- Servicio de Neumología, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, Madrid, Spain
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Bergholt NL, Demirel A, Pedersen M, Ding M, Kragstrup TW, Andersen T, Deleuran BW, Foldager CB. Intermittent Hypoxic Therapy Inhibits Allogenic Bone-Graft Resorption by Inhibition of Osteoclastogenesis in a Mouse Model. Int J Mol Sci 2021; 23:323. [PMID: 35008749 PMCID: PMC8745522 DOI: 10.3390/ijms23010323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/14/2021] [Accepted: 12/24/2021] [Indexed: 01/04/2023] Open
Abstract
Systemic Intermittent Hypoxic Therapy (IHT) relies on the adaptive response to hypoxic stress. We investigated allogenic bone-graft resorption in the lumbar spine in 48 mice. The mice were exposed to IHT for 1 week before surgery or 1 week after surgery and compared with controls after 1 and 4 weeks. Complete graft resorption was observed in 33-36% of the animals in the control group, but none in the preoperative IHT group. Increased bone-graft volume was demonstrated by micro-computed tomography in the preoperative IHT group after 1 week (p = 0.03) while a non-significant difference was observed after 4 weeks (p = 0.12). There were no significant differences in the postoperative IHT group. Increased concentration of immune cells was localized in the graft area, and more positive tartrate-resistant acid phosphatase (TRAP) staining was found in controls compared with IHT allogenic bone grafts. Systemic IHT resulted in a significant increase of the major osteoclast inhibitor osteoprotegerin as well as osteogenic and angiogenic regulators Tgfbr3, Fst3l, Wisp1, and Vegfd. Inflammatory cytokines and receptor activator of nuclear factor kappa-B ligand (RANKL) stimulators IL-6, IL-17a, IL-17f, and IL-23r increased after 1 and 4 weeks, and serum RANKL expression remained constant while Ccl3 and Ccl5 decreased. We conclude that the adaptive response to IHT activates numerous pathways leading to inhibition of osteoclastic activity and inhibition of allogenic bone-graft resorption.
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Affiliation(s)
- Natasja Leth Bergholt
- Orthopaedic Research Laboratory, Aarhus University Hospital, 8200 Aarhus, Denmark; (N.L.B.); (A.D.)
| | - Ari Demirel
- Orthopaedic Research Laboratory, Aarhus University Hospital, 8200 Aarhus, Denmark; (N.L.B.); (A.D.)
| | - Michael Pedersen
- Comparative Medicine Laboratory, Aarhus University, 8200 Aarhus, Denmark;
| | - Ming Ding
- Department of Orthopaedic Surgery and Traumatology, Odense University Hospital and University of Southern Denmark, 5000 Odense, Denmark;
| | - Tue Wenzel Kragstrup
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (T.W.K.); (T.A.); (B.W.D.)
- Department of Rheumatology, Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Thomas Andersen
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (T.W.K.); (T.A.); (B.W.D.)
| | - Bent Winding Deleuran
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (T.W.K.); (T.A.); (B.W.D.)
- Department of Rheumatology, Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Casper Bindzus Foldager
- Orthopaedic Research Laboratory, Aarhus University Hospital, 8200 Aarhus, Denmark; (N.L.B.); (A.D.)
- Comparative Medicine Laboratory, Aarhus University, 8200 Aarhus, Denmark;
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Pulmonary Hypertension in Acute and Chronic High Altitude Maladaptation Disorders. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18041692. [PMID: 33578749 PMCID: PMC7916528 DOI: 10.3390/ijerph18041692] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 12/13/2022]
Abstract
Alveolar hypoxia is the most prominent feature of high altitude environment with well-known consequences for the cardio-pulmonary system, including development of pulmonary hypertension. Pulmonary hypertension due to an exaggerated hypoxic pulmonary vasoconstriction contributes to high altitude pulmonary edema (HAPE), a life-threatening disorder, occurring at high altitudes in non-acclimatized healthy individuals. Despite a strong physiologic rationale for using vasodilators for prevention and treatment of HAPE, no systematic studies of their efficacy have been conducted to date. Calcium-channel blockers are currently recommended for drug prophylaxis in high-risk individuals with a clear history of recurrent HAPE based on the extensive clinical experience with nifedipine in HAPE prevention in susceptible individuals. Chronic exposure to hypoxia induces pulmonary vascular remodeling and development of pulmonary hypertension, which places an increased pressure load on the right ventricle leading to right heart failure. Further, pulmonary hypertension along with excessive erythrocytosis may complicate chronic mountain sickness, another high altitude maladaptation disorder. Importantly, other causes than hypoxia may potentially underlie and/or contribute to pulmonary hypertension at high altitude, such as chronic heart and lung diseases, thrombotic or embolic diseases. Extensive clinical experience with drugs in patients with pulmonary arterial hypertension suggests their potential for treatment of high altitude pulmonary hypertension. Small studies have demonstrated their efficacy in reducing pulmonary artery pressure in high altitude residents. However, no drugs have been approved to date for the therapy of chronic high altitude pulmonary hypertension. This work provides a literature review on the role of pulmonary hypertension in the pathogenesis of acute and chronic high altitude maladaptation disorders and summarizes current knowledge regarding potential treatment options.
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8
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Li L, Xu M, Rowan SC, Howell K, Russell-Hallinan A, Donnelly SC, McLoughlin P, Baugh JA. The effects of genetic deletion of Macrophage migration inhibitory factor on the chronically hypoxic pulmonary circulation. Pulm Circ 2021; 10:2045894020941352. [PMID: 33447370 PMCID: PMC7780187 DOI: 10.1177/2045894020941352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/18/2020] [Indexed: 11/17/2022] Open
Abstract
While it is well established that the haemodynamic cause of hypoxic pulmonary hypertension is increased pulmonary vascular resistance, the molecular pathogenesis of the increased resistance remains incompletely understood. Macrophage migration inhibitory factor is a pleiotropic cytokine with endogenous tautomerase enzymatic activity as well as both intracellular and extracellular signalling functions. In several diseases, macrophage migration inhibitory factor has pro-inflammatory roles that are dependent upon signalling through the cell surface receptors CD74, CXCR2 and CXCR4. Macrophage migration inhibitory factor expression is increased in animal models of hypoxic pulmonary hypertension and macrophage migration inhibitory factor tautomerase inhibitors, which block some of the functions of macrophage migration inhibitory factor, and have been shown to attenuate hypoxic pulmonary hypertension in mice and monocrotaline-induced pulmonary hypertension in rats. However, because of the multiple pathways through which it acts, the integrated actions of macrophage migration inhibitory factor during the development of hypoxic pulmonary hypertension were unclear. We report here that isolated lungs from adult macrophage migration inhibitory factor knockout (MIF-/- ) mice maintained in normoxic conditions showed greater acute hypoxic vasoconstriction than the lungs of wild type mice (MIF+/+ ). Following exposure to hypoxia for three weeks, isolated lungs from MIF-/- mice had significantly higher pulmonary vascular resistance than those from MIF+/+ mice. The major mechanism underlying the greater increase in pulmonary vascular resistance in the hypoxic MIF-/- mice was reduction of the pulmonary vascular bed due to an impairment of the normal hypoxia-induced expansion of the alveolar capillary network. Taken together, these results demonstrate that macrophage migration inhibitory factor plays a central role in the development of the pulmonary vascular responses to chronic alveolar hypoxia.
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Affiliation(s)
- Lili Li
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Maojia Xu
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Simon C Rowan
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Katherine Howell
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Adam Russell-Hallinan
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Seamas C Donnelly
- Department of Medicine, Tallaght University Hospital & Trinity College Dublin, Dublin, Ireland
| | - Paul McLoughlin
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - John A Baugh
- UCD Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
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Shiraishi H, Chida-Nagai A, Taniguchi K, Abe J, Izumi G, Yamazawa H, Ueda Y, Sasaki O, Miyakoshi K, Takeda A. Diagnostic dilemma in a case of obstructive sleep apnoea syndrome with reversible pulmonary hypertension and right heart failure: A case report. Int J Pediatr Otorhinolaryngol 2020; 138:110378. [PMID: 33152969 DOI: 10.1016/j.ijporl.2020.110378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/08/2020] [Accepted: 09/08/2020] [Indexed: 10/23/2022]
Abstract
Childhood obstructive sleep apnoea syndrome (OSAS) secondary to adenoid hyperplasia is known to give rise to pulmonary hypertension. However, we present a case of a toddler with pulmonary hypertension (PH) and right heart failure due to OSAS, the cause of which is difficult to identify. After the patient underwent an adenotonsillectomy, OSAS disappeared and the PH eventually resolved. Both paediatricians and otolaryngologists should know that paediatric OSAS can occur even in the setting of mild, clinically insignificant palatine tonsil hypertrophy and adenoid hyperplasia. Surgical intervention should be considered without losing the opportunity if it could be the cause of PH.
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Affiliation(s)
- Haruki Shiraishi
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan; Department of Pediatrics, Japanese Red Cross Kitami Hospital, Kitami, Japan
| | - Ayako Chida-Nagai
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan.
| | - Kota Taniguchi
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan
| | - Jiro Abe
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan
| | - Gaku Izumi
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan
| | - Hirokuni Yamazawa
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan
| | - Yuki Ueda
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan
| | - Osamu Sasaki
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan; Department of Pediatrics, Tenshi Hospital, Sapporo, Japan
| | - Kosei Miyakoshi
- Department of Otolaryngology, Tenshi Hospital, Sapporo, Japan
| | - Atsuhito Takeda
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan
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Yan S, Resta TC, Jernigan NL. Vasoconstrictor Mechanisms in Chronic Hypoxia-Induced Pulmonary Hypertension: Role of Oxidant Signaling. Antioxidants (Basel) 2020; 9:E999. [PMID: 33076504 PMCID: PMC7602539 DOI: 10.3390/antiox9100999] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/06/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023] Open
Abstract
Elevated resistance of pulmonary circulation after chronic hypoxia exposure leads to pulmonary hypertension. Contributing to this pathological process is enhanced pulmonary vasoconstriction through both calcium-dependent and calcium sensitization mechanisms. Reactive oxygen species (ROS), as a result of increased enzymatic production and/or decreased scavenging, participate in augmentation of pulmonary arterial constriction by potentiating calcium influx as well as activation of myofilament sensitization, therefore mediating the development of pulmonary hypertension. Here, we review the effects of chronic hypoxia on sources of ROS within the pulmonary vasculature including NADPH oxidases, mitochondria, uncoupled endothelial nitric oxide synthase, xanthine oxidase, monoamine oxidases and dysfunctional superoxide dismutases. We also summarize the ROS-induced functional alterations of various Ca2+ and K+ channels involved in regulating Ca2+ influx, and of Rho kinase that is responsible for myofilament Ca2+ sensitivity. A variety of antioxidants have been shown to have beneficial therapeutic effects in animal models of pulmonary hypertension, supporting the role of ROS in the development of pulmonary hypertension. A better understanding of the mechanisms by which ROS enhance vasoconstriction will be useful in evaluating the efficacy of antioxidants for the treatment of pulmonary hypertension.
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Affiliation(s)
| | | | - Nikki L. Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA; (S.Y.); (T.C.R.)
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Yoo HHB. Lesões Plexiformes na Hipertensão Arterial Pulmonar: Estamos Ficando mais Próximos do Manejo com mais Paciência e Rigor? Arq Bras Cardiol 2020; 115:491-492. [PMID: 33027371 PMCID: PMC9363101 DOI: 10.36660/abc.20200832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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LncRNA Tug1 involves in the pulmonary vascular remodeling in mice with hypoxic pulmonary hypertension via the microRNA-374c-mediated Foxc1. Life Sci 2019; 237:116769. [DOI: 10.1016/j.lfs.2019.116769] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 02/07/2023]
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13
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Volumetric optoacoustic tomography enables non-invasive in vivo characterization of impaired heart function in hypoxic conditions. Sci Rep 2019; 9:8369. [PMID: 31182733 PMCID: PMC6557887 DOI: 10.1038/s41598-019-44818-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/21/2019] [Indexed: 12/28/2022] Open
Abstract
Exposure to chronic hypoxia results in pulmonary hypertension characterized by increased vascular resistance and pulmonary vascular remodeling, changes in functional parameters of the pulmonary vasculature, and right ventricular hypertrophy, which can eventually lead to right heart failure. The underlying mechanisms of hypoxia-induced pulmonary hypertension have still not been fully elucidated while no curative treatment is currently available. Commonly employed pre-clinical analytic methods are largely limited to invasive studies interfering with cardiac tissue or otherwise ex vivo functional studies and histopathology. In this work, we suggest volumetric optoacoustic tomography (VOT) for non-invasive assessment of heart function in response to chronic hypoxia. Mice exposed for 3 consecutive weeks to normoxia or chronic hypoxia were imaged in vivo with heart perfusion tracked by VOT using indocyanide green contrast agent at high temporal (100 Hz) and spatial (200 µm) resolutions in 3D. Unequivocal difference in the pulmonary transit time was revealed between the hypoxic and normoxic conditions concomitant with the presence of pulmonary vascular remodeling within hypoxic models. Furthermore, a beat-to-beat analysis of the volumetric image data enabled identifying and characterizing arrhythmic events in mice exposed to chronic hypoxia. The newly introduced non-invasive methodology for analysis of impaired pulmonary vasculature and heart function under chronic hypoxic exposure provides important inputs into development of early diagnosis and treatment strategies in pulmonary hypertension.
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Wang F, Xu X, Tang W, Min L, Yang J. Rab6A GTPase contributes to phenotypic modulation in pulmonary artery smooth muscle cells under hypoxia. J Cell Biochem 2019; 120:7858-7867. [PMID: 30417421 DOI: 10.1002/jcb.28060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 10/22/2018] [Indexed: 01/24/2023]
Abstract
Previous studies have demonstrated that hypoxia can induce phenotypic modulation of pulmonary smooth muscle cells; however, the mechanisms remain unclear. The present study aimed to investigate the effect of the GTPase Rab6A-mediated phenotypic modulation and other activities of rat pulmonary artery smooth muscle cells (RPASMCs). We revealed that Rab6A was induced by hypoxia (1% O2 ) and was involved in a hypoxia-induced phenotypic switch and endoplasmic reticulum stress (ERS) in RPASMCs. After 48 hours of hypoxia, the expression of the phenotype marker protein smooth muscle actin was downregulated and vimentin (VIM) expression was upregulated. Rab6A was upregulated after 48 hours of hypoxia, and the level of glucose-regulated protein, 78 kDa (GRP78) after 12 hours of hypoxic stimulation was also increased. After transfection with a Rab6A short interfering RNA under hypoxic conditions, the expression levels of GRP78 and VIM in RPASMCs were downregulated. Overall, hypoxia-induced RPASMCs to undergo ERS followed by phenotypic transformation. Rab6A is involved in this hypoxia-induced phenotypic modulation and ERS in RPASMCs.
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Affiliation(s)
- Fang Wang
- Department of Respiratory Medicine, Northern Jiangsu People's Hospital, Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Xingxiang Xu
- Department of Respiratory Medicine, Northern Jiangsu People's Hospital, Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Weian Tang
- Department of Respiratory Medicine, Northern Jiangsu People's Hospital, Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Lingfeng Min
- Department of Respiratory Medicine, Northern Jiangsu People's Hospital, Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Junjun Yang
- Department of Respiratory Medicine, Northern Jiangsu People's Hospital, Clinical Medical College of Yangzhou University, Yangzhou, China
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15
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Katz MG, Fargnoli AS, Gubara SM, Bisserier M, Sassi Y, Bridges CR, Hajjar RJ, Hadri L. The Left Pneumonectomy Combined with Monocrotaline or Sugen as a Model of Pulmonary Hypertension in Rats. J Vis Exp 2019. [PMID: 30907889 DOI: 10.3791/59050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In this protocol, we detail the correct procedural steps and necessary precautions to successfully perform a left pneumonectomy and induce PAH in rats with the additional administration of monocrotaline (MCT) or SU5416 (Sugen). We also compare these two models to other PAH models commonly used in research. In the last few years, the focus of animal PAH models has moved towards studying the mechanism of angioproliferation of plexiform lesions, in which the role of increased pulmonary blood flow is considered as an important trigger in the development of severe pulmonary vascular remodeling. One of the most promising rodent models of increased pulmonary flow is the unilateral left pneumonectomy combined with a "second hit" of MCT or Sugen. The removal of the left lung leads to increased and turbulent pulmonary blood flow and vascular remodeling. Currently, there is no detailed procedure of the pneumonectomy surgery in rats. This article details a step-by-step protocol of the pneumonectomy surgical procedure and post-operative care in male Sprague-Dawley rats. Briefly, the animal is anesthetized and the chest is opened. Once the left pulmonary artery, pulmonary vein, and bronchus are visualized, they are ligated and the left lung is removed. The chest then closed and the animal recovered. Blood is forced to circulate only on the right lung. This increased vascular pressure leads to a progressive remodeling and occlusion of small pulmonary arteries. The second hit of MCT or Sugen is used one week post-surgery to induce endothelial dysfunction. The combination of increased blood flow in the lung and endothelial dysfunction produces severe PAH. The primary limitation of this procedure is that it requires general surgical skills.
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Affiliation(s)
- Michael G Katz
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Anthony S Fargnoli
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Sarah M Gubara
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Malik Bisserier
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Yassine Sassi
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Charles R Bridges
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Roger J Hajjar
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai
| | - Lahouaria Hadri
- Cardiovascular Research Center, Department of Cardiology, Icahn School of Medicine at Mount Sinai;
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Nox1/Ref-1-mediated activation of CREB promotes Gremlin1-driven endothelial cell proliferation and migration. Redox Biol 2019; 22:101138. [PMID: 30802716 PMCID: PMC6395885 DOI: 10.1016/j.redox.2019.101138] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 01/25/2019] [Accepted: 02/05/2019] [Indexed: 01/21/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a complex degenerative disorder marked by aberrant vascular remodeling associated with hyperproliferation and migration of endothelial cells (ECs). Previous reports implicated bone morphogenetic protein antagonist Gremlin 1 in this process; however, little is known of the molecular mechanisms involved. The current study was designed to test whether redox signaling initiated by NADPH oxidase 1 (Nox1) could promote transcription factor CREB activation by redox factor 1 (Ref-1), transactivation of Gremlin1 transcription, EC migration, and proliferation. Human pulmonary arterial EC (HPAECs) exposed in vitro to hypoxia to recapitulate PAH signaling displayed induced Nox1 expression, reactive oxygen species (ROS) production, PKA activity, CREB phosphorylation, and CREB:CRE motif binding. These responses were abrogated by selective Nox1 inhibitor NoxA1ds and/or siRNA Nox1. Nox1-activated CREB migrated to the nucleus and bound to Ref-1 leading to CREB:CRE binding and Gremlin1 transcription. CHiP assay and CREB gene-silencing illustrated that CREB is pivotal for hypoxia-induced Gremlin1, which, in turn, stimulates EC proliferation and migration. In vivo, participation of Nox1, CREB, and Gremlin1, as well as CREB:CRE binding was corroborated in a rat PAH model. Activation of a previously unidentified Nox1-PKA-CREB/Ref-1 signaling pathway in pulmonary endothelial cells leads to Gremlin1 transactivation, proliferation and migration. These findings reveal a new signaling pathway by which Nox1 via induction of CREB and Gremlin1 signaling contributes to vascular remodeling and provide preclinical indication of its significance in PAH.
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Kassa B, Mickael C, Kumar R, Sanders L, Koyanagi D, Hernandez-Saavedra D, Tuder RM, Graham BB. Paclitaxel blocks Th2-mediated TGF-β activation in Schistosoma mansoni-induced pulmonary hypertension. Pulm Circ 2018; 9:2045894018820813. [PMID: 30511588 PMCID: PMC6304706 DOI: 10.1177/2045894018820813] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Schistosomiasis is a leading cause of pulmonary hypertension (PH) worldwide.
Recent studies reveal that the type-2 immune cytokines IL-4 and IL-13, as well
as consequent activation of TGF-β, are key factors in the pathogenesis of
Schistosoma-PH. Paclitaxel has been reported to act as an
adjuvant for Th2 inflammation while downregulating TGF-β activation. Moreover,
paclitaxel blocks PH in monocrotaline and SU5416-hypoxia models. We hypothesized
that paclitaxel would augment Th2 inflammation while blocking TGF-β activation
and PH after schistosomiasis exposure. Wild-type mice (C57BL6/J; 6/group) were
intraperitoneally (IP) sensitized and then intravenously (IV) challenged with
Schistosoma mansoni eggs. One day after IV egg challenge,
the mice were treated with a single IP dose of 25 mg/kg paclitaxel or vehicle.
Right ventricular (RV) catheterization was performed and granuloma volumes and
vascular remodeling were quantified. Lung cytokines were quantified by ELISA and
reverse transcription polymerase chain reaction, and the quantity of active
TGF-β was determined using a cell reporter line. We also investigated
hypoxia-induced PH. Paclitaxel treatment significantly protected mice from
Schistosoma-PH, with decreased RV systolic pressure
(P = 0.005) and pulmonary vascular media thickness.
Inflammation was significantly suppressed, contrary to our hypothesis, with
decreased IL-4 and IL-13 levels, smaller granulomas, and less active TGF-β
following paclitaxel treatment. There was no change in IFN-γ or FoxO1 or FoxO3
expression. Paclitaxel did not suppress chronic hypoxia-induced PH, which is
also TGF-β-driven but independent of type-2 immunity. Paclitaxel protects
against Schistosoma-induced PH in mice, although by blocking
proximate Th2 inflammation rather than suppressing distal TGF-β activation.
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Affiliation(s)
- Biruk Kassa
- Program in Translational Lung Research, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Claudia Mickael
- Program in Translational Lung Research, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Rahul Kumar
- Program in Translational Lung Research, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Linda Sanders
- Program in Translational Lung Research, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Dan Koyanagi
- Program in Translational Lung Research, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Daniel Hernandez-Saavedra
- Program in Translational Lung Research, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Rubin M Tuder
- Program in Translational Lung Research, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Brian B Graham
- Program in Translational Lung Research, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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Tsantan Sumtang Alleviates Chronic Hypoxia-Induced Pulmonary Hypertension by Inhibiting Proliferation of Pulmonary Vascular Cells. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9504158. [PMID: 30622966 PMCID: PMC6304203 DOI: 10.1155/2018/9504158] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/23/2018] [Accepted: 11/01/2018] [Indexed: 12/12/2022]
Abstract
Hypoxia-induced pulmonary hypertension (HPH) is a severe condition associated with significant morbidity and mortality in people living at high altitude. Tsantan Sumtang, a traditional Tibetan medicine, has been routinely used for the treatment of cardiopyretic disease, as well as stenocardia. Interestingly, our previous research found that Tsantan Sumtang improved HPH in rats maintaining in a hypobaric chamber. We performed a series of experiments to test the indexes of vasoconstriction and vascular remodeling, the key pathophysiological characteristics of HPH. Our results showed that Tsantan Sumtang relaxed noradrenaline (NE)-precontracted rat pulmonary artery rings in a concentration-dependent manner in vitro. The PGI2-cAMP (prostaglandin I2-cyclic adenosine monophosphate) pathway, NO-cGMP (nitric oxide-cyclic guanosine monophosphate) pathway, and the opening of K+ channels (inward rectifier K+ channels, large conductance Ca2+-activated K+ channels, and voltage-dependent K+ channels) might play major roles in the vasorelaxation effect. In vivo, the administration of Tsantan Sumtang resulted in a substantial decrease in the rat mean pulmonary artery pressure (mPAP) and the right ventricular hypertrophy index (RVHI). The reduction of thickness of small pulmonary arterial wall and the WT% (the ratio of the vascular wall thickness to the vascular diameter) were observed. The smooth muscle muscularization of the arterials was alleviated by Tsantan Sumtang treatment at the same time. Tsantan Sumtang also reduced remodeling of pulmonary arterioles by suppressing the expression of proliferating cell nuclear antigen (PCNA), α-smooth muscle actin (α-SMA), cyclin D1, and cyclin-dependent kinase 4 (CDK4) through inhibition of p27Kip1 degradation. Therefore, Tsantan Sumtang could be applied as a preventative medication for HPH, which would be a new use for this traditional medicine.
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Rowan SC, Rochfort KD, Piouceau L, Cummins PM, O’Rourke M, McLoughlin P. Pulmonary endothelial permeability and tissue fluid balance depend on the viscosity of the perfusion solution. Am J Physiol Lung Cell Mol Physiol 2018; 315:L476-L484. [DOI: 10.1152/ajplung.00437.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Fluid filtration in the pulmonary microcirculation depends on the hydrostatic and oncotic pressure gradients across the endothelium and the selective permeability of the endothelial barrier. Maintaining normal fluid balance depends both on specific properties of the endothelium and of the perfusing blood. Although some of the essential properties of blood needed to prevent excessive fluid leak have been identified and characterized, our understanding of these remains incomplete. The role of perfusate viscosity in maintaining normal fluid exchange has not previously been examined. We prepared a high-viscosity perfusion solution (HVS) with a relative viscosity of 2.5, i.e., within the range displayed by blood flowing in vessels of different diameters in vivo (1.5–4.0). Perfusion of isolated murine lungs with HVS significantly reduced the rate of edema formation compared with perfusion with a standard solution (SS), which had a lower viscosity similar to plasma (relative viscosity 1.5). HVS did not alter capillary filtration pressure. Increased endothelial shear stress produced by increasing flow rates of SS, to mimic the increased shear stress produced by HVS, did not reduce edema formation. HVS significantly reduced extravasation of Evans blue-labeled albumin compared with SS, indicating that it attenuated endothelial leak. These findings demonstrate for the first time that the viscosity of the solution perfusing the pulmonary microcirculation is an important physiological property contributing to the maintenance of normal fluid exchange. This has significant implications for our understanding of fluid homeostasis in the healthy lung, edema formation in disease, and reconditioning of donor organs for transplantation.
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Affiliation(s)
- Simon C. Rowan
- University College Dublin School of Medicine and Conway Institute, University College Dublin, Dublin, Ireland
| | - Keith D. Rochfort
- National Institute of Cellular Biotechnology, School of Biotechnology, Dublin City University, Dublin, Ireland
| | - Lucie Piouceau
- University College Dublin School of Medicine and Conway Institute, University College Dublin, Dublin, Ireland
| | - Philip M. Cummins
- National Institute of Cellular Biotechnology, School of Biotechnology, Dublin City University, Dublin, Ireland
| | - Malachy O’Rourke
- School of Mechanical and Materials Engineering, University College Dublin, Dublin, Ireland
| | - Paul McLoughlin
- University College Dublin School of Medicine and Conway Institute, University College Dublin, Dublin, Ireland
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20
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Rowan SC, Keane MP, Gaine S, McLoughlin P. Hypoxic pulmonary hypertension in chronic lung diseases: novel vasoconstrictor pathways. THE LANCET RESPIRATORY MEDICINE 2016; 4:225-36. [PMID: 26895650 DOI: 10.1016/s2213-2600(15)00517-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/03/2015] [Accepted: 12/07/2015] [Indexed: 11/29/2022]
Abstract
Pulmonary hypertension is a well recognised complication of chronic hypoxic lung diseases, which are among the most common causes of death and disability worldwide. Development of pulmonary hypertension independently predicts reduced life expectancy. In chronic obstructive pulmonary disease, long-term oxygen therapy ameliorates pulmonary hypertension and greatly improves survival, although the correction of alveolar hypoxia and pulmonary hypertension is only partial. Advances in understanding of the regulation of vascular smooth muscle tone show that chronic vasoconstriction plays a more important part in the pathogenesis of hypoxic pulmonary hypertension than previously thought, and that structural vascular changes contribute less. Trials of existing vasodilators show that pulmonary hypertension can be ameliorated and systemic oxygen delivery improved in carefully selected patients, although systemic hypotensive effects limit the doses used. Vasoconstrictor pathways that are selective for the pulmonary circulation can be blocked to reduce hypoxic pulmonary hypertension without causing systemic hypotension, and thus provide potential targets for novel therapeutic strategies.
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Affiliation(s)
- Simon C Rowan
- UCD School of Medicine, Conway Institute, Dublin, Ireland
| | - Michael P Keane
- UCD School of Medicine, Respiratory Medicine, St Vincent's University Hospital, Dublin, Ireland
| | - Seán Gaine
- National Pulmonary Hypertension Unit, Mater Misericordiae University Hospital, Dublin, Ireland
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Abstract
Duchenne muscular dystrophy (DMD) is a progressive striated muscle disease that is characterized by skeletal muscle weakness with progressive respiratory and cardiac failure. Together respiratory and cardiac disease account for the majority of mortality in the DMD patient population. However, little is known regarding the effects of respiratory dysfunction on the dystrophic heart. The studies described here examine the effects of acute hypoxia on cardiac function. These studies demonstrate, for the first time, that a mouse model of DMD displays significant mortality following acute exposure to hypoxia. This mortality is characterized by a steady decline in systolic function. Retrospective analysis reveals that significant decreases in diastolic dysfunction, especially in the right ventricle, precede the decline in systolic pressure. The initial hemodynamic response to acute hypoxia in the mouse is similar to that observed in larger species, with significant increases in right ventricular afterload and decreases in left ventricular preload being observed. Significant increases in heart rate and contractility suggest hypoxia-induced activation of the sympathetic nervous system. These studies provide evidence that while hypoxia presents significant hemodynamic challenges to the dystrophic right ventricle, global cardiac dysfunction precedes hypoxia-induced mortality in the dystrophic heart. These findings are clinically relevant as the respiratory insufficiency evident in patients with DMD results in significant bouts of hypoxia. The results of these studies indicate that hypoxia may contribute to the acceleration of the heart disease in DMD patients. Importantly, hypoxia can be avoided through the use of ventilatory support.
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Affiliation(s)
- DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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22
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Affiliation(s)
- P. McLoughlin
- University College Dublin School of Medicine and Medical Sciences Conway Institute Dublin Ireland
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23
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Wilkins MR, Ghofrani HA, Weissmann N, Aldashev A, Zhao L. Pathophysiology and Treatment of High-Altitude Pulmonary Vascular Disease. Circulation 2015; 131:582-90. [DOI: 10.1161/circulationaha.114.006977] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Martin R. Wilkins
- From Experimental Medicine, Imperial College London, Hammersmith Hospital, United Kingdom (M.R.W., H.-A.G., L.Z.); Excellence Cluster Cardio-Pulmonary System, Universities of Giessen, Germany (M.R.W., H.-A.G., N.W., L.Z.); University of Giessen Marburg Lung Center, Justus-Liebig-University, Germany (M.R.W., H.-A.G., N.W., L.Z.); Kerckhoff Clinic, Bad Nauheim, Germany (H.-A.G.); Institute of Molecular Biology and Medicine, Bishkek, Kyrgyzstan (A.A.)
| | - Hossein-Ardeschir Ghofrani
- From Experimental Medicine, Imperial College London, Hammersmith Hospital, United Kingdom (M.R.W., H.-A.G., L.Z.); Excellence Cluster Cardio-Pulmonary System, Universities of Giessen, Germany (M.R.W., H.-A.G., N.W., L.Z.); University of Giessen Marburg Lung Center, Justus-Liebig-University, Germany (M.R.W., H.-A.G., N.W., L.Z.); Kerckhoff Clinic, Bad Nauheim, Germany (H.-A.G.); Institute of Molecular Biology and Medicine, Bishkek, Kyrgyzstan (A.A.)
| | - Norbert Weissmann
- From Experimental Medicine, Imperial College London, Hammersmith Hospital, United Kingdom (M.R.W., H.-A.G., L.Z.); Excellence Cluster Cardio-Pulmonary System, Universities of Giessen, Germany (M.R.W., H.-A.G., N.W., L.Z.); University of Giessen Marburg Lung Center, Justus-Liebig-University, Germany (M.R.W., H.-A.G., N.W., L.Z.); Kerckhoff Clinic, Bad Nauheim, Germany (H.-A.G.); Institute of Molecular Biology and Medicine, Bishkek, Kyrgyzstan (A.A.)
| | - Almaz Aldashev
- From Experimental Medicine, Imperial College London, Hammersmith Hospital, United Kingdom (M.R.W., H.-A.G., L.Z.); Excellence Cluster Cardio-Pulmonary System, Universities of Giessen, Germany (M.R.W., H.-A.G., N.W., L.Z.); University of Giessen Marburg Lung Center, Justus-Liebig-University, Germany (M.R.W., H.-A.G., N.W., L.Z.); Kerckhoff Clinic, Bad Nauheim, Germany (H.-A.G.); Institute of Molecular Biology and Medicine, Bishkek, Kyrgyzstan (A.A.)
| | - Lan Zhao
- From Experimental Medicine, Imperial College London, Hammersmith Hospital, United Kingdom (M.R.W., H.-A.G., L.Z.); Excellence Cluster Cardio-Pulmonary System, Universities of Giessen, Germany (M.R.W., H.-A.G., N.W., L.Z.); University of Giessen Marburg Lung Center, Justus-Liebig-University, Germany (M.R.W., H.-A.G., N.W., L.Z.); Kerckhoff Clinic, Bad Nauheim, Germany (H.-A.G.); Institute of Molecular Biology and Medicine, Bishkek, Kyrgyzstan (A.A.)
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Affiliation(s)
- S C Rowan
- UCD School of Medicine and Medical Sciences, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - P McLoughlin
- UCD School of Medicine and Medical Sciences, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
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Pandit LM, Lloyd EE, Reynolds JO, Lawrence WS, Reynolds C, Wehrens XHT, Bryan RM. TWIK-2 channel deficiency leads to pulmonary hypertension through a rho-kinase-mediated process. Hypertension 2014; 64:1260-5. [PMID: 25245387 DOI: 10.1161/hypertensionaha.114.03406] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
TWIK-2 (KCNK6) is a member of the 2-pore domain (K2P) family of potassium channels, which are highly expressed in the vascular system. We tested the hypothesis that TWIK-2 deficiency leads to pulmonary hypertension. TWIK-2 knockout mice and their wildtype littermates at 8 weeks of age had similar mean right ventricular systolic pressures (24±3 and 21±3 mm Hg, respectively.) Significantly, by 20 weeks of age, the mean right ventricular systolic pressures in TWIK-2 knockout mice increased to 35±3 mm Hg (P≤0.036), whereas mean right ventricular systolic pressures in wildtype littermates remained at 22±3 mm Hg. Elevated mean right ventricular systolic pressures in the TWIK-2 knockout mice was accompanied by pulmonary vascular remodeling as determined by a 25% increase in the cross-sectional area of the vessels occupied by the vessel wall. Additionally, secondary branches of the pulmonary artery from 20-week-old TWIK-2 knockout mice showed an enhanced contractile response to U46619 (10(-6) moles/L), a thromboxane A2 mimetic, which was completely abolished with the Rho-kinase inhibitor, Y27632 (10(-6) and 10(-5) moles/L). Treatment of TWIK-2 knockout mice with the Rho-kinase inhibitor, fasudil, in the drinking water for 12 weeks, abolished the development of pulmonary hypertension and attenuated the vessel remodeling. We concluded that mice deficient in the TWIK-2 channel develop pulmonary hypertension between 8 and 20 weeks of age through a mechanism involving Rho-kinase. Our results suggest that downregulation of TWIK-2 in the pulmonary vasculature may be an underlying mechanism in the development of pulmonary hypertension.
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Affiliation(s)
- Lavannya M Pandit
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Eric E Lloyd
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Julia O Reynolds
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - William S Lawrence
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Corey Reynolds
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Xander H T Wehrens
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
| | - Robert M Bryan
- From the Departments of Internal Medicine (L.M.P., X.H.T.W., R.M.B.), Anesthesiology (E.E.L., R.M.B.), Cardiovascular Research Institute, Department of Molecular Physiology and Biophysics (J.O.R., C.R., X.H.T.W., R.M.B.), Baylor College of Medicine, and Department of Microbiology and Immunology (W.S.L.), The University of Texas Medical Branch
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26
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Grant JS, Morecroft I, Dempsie Y, van Rooij E, MacLean MR, Baker AH. Transient but not genetic loss of miR-451 is protective in the development of pulmonary arterial hypertension. Pulm Circ 2014; 3:840-50. [PMID: 25006399 DOI: 10.1086/674751] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 09/28/2013] [Indexed: 11/03/2022] Open
Abstract
MicroRNAs are small noncoding RNAs involved in the regulation of gene expression and have recently been implicated in the development of pulmonary arterial hypertension (PAH). Previous work has established that miR-451 is upregulated in rodent models of PAH. The role of miR-451 in the pulmonary circulation is unknown. We therefore sought to assess the involvement of miR-451 in the development of PAH. Silencing of miR-451 was performed in vivo using miR-451 knockout mice and an anti-miR targeting mature miR-451 in rats. Coupled with exposure to hypoxia, indices of PAH were assessed. The effect of modulating miR-451 on human pulmonary artery smooth muscle cell proliferation and migration was analyzed. We observed a reduction in systolic right ventricular pressure in hypoxic rats pretreated with anti-miR-451 compared with hypoxia alone ([Formula: see text] mmHg and [Formula: see text] mmHg, respectively; [Formula: see text]). In miR-451 knockout mice, compared with wild-type hypoxic mice, no significant differences were observed following exposure to chronic hypoxia. In vitro analysis demonstrated that overexpression of miR-451 in human pulmonary artery smooth muscle cells promoted migration under serum-free conditions. No effect on cellular proliferation was observed. In conclusion, transient inhibition of miR-451 attenuated the development of PAH in hypoxia-exposed rats. Genetic deletion of miR-451 had no beneficial effect on indices of PAH, potentially because of pathway redundancy compensating for the loss of miR-451.
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Affiliation(s)
- Jennifer S Grant
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Ian Morecroft
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Yvonne Dempsie
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Margaret R MacLean
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Andrew H Baker
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
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27
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Salazar Vázquez BY, Salazar Vázquez MA, Chávez-Negrete A, Escobedo G, Cabrales P, Subramaniam S, Intaglietta M, Pérez-Tamayo R. Influence of serological factors and BMI on the blood pressure/hematocrit association in healthy young men and women. Vasc Health Risk Manag 2014; 10:271-7. [PMID: 24851053 PMCID: PMC4018417 DOI: 10.2147/vhrm.s60130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The association between mean arterial blood pressure (MAP) and hematocrit (Hct) as a surrogate for blood viscosity was investigated in a young (average 20.0±2.3 years), healthy population of 174 men and 442 women. Health status was assessed by clinical examination and serological evaluation. Individuals with severe anemia or hemoconcentration, prior traumas or major surgical intervention, smokers, and pregnant or lactating women were excluded from the study. The MAP/Hct association was positive and significant (P=0.04) for women and negative, albeit not significantly so, for men. The MAP/Hct association was also evaluated in subgroups of the same population with a progressive step-by-step exclusion of: individuals with cholesterol >200 mg/dL; triglycerides >200 mg/dL; body mass index >25 kg/m(2); and glucose >100 mg/dL. This consecutively reduced the strength of the positive MAP/Hct association in women, which became negative - although not significantly so - when all anomalously high factors were excluded. The same trend was found in men. Our study indicates that previously reported positive trends in the relationship between the MAP and Hct in the population are not present in a young, healthy population of men or women that excludes individuals with the confounding factors of above normal serological values and BMI.
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Affiliation(s)
- Beatriz Y Salazar Vázquez
- Faculty of Medicine, Universidad Juárez del Estado de Durango, Victoria de Durango, Dgo, Mexico ; Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico ; Department of Bioengineering, University of California, San Diego, CA, USA
| | - Miguel A Salazar Vázquez
- Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico ; Department of Pediatrics, Hospital General de Zona No. 1, Instituto Mexicano del Seguro Social, Durango, Dgo, Mexico
| | | | - Galileo Escobedo
- Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico
| | - Pedro Cabrales
- Department of Bioengineering, University of California, San Diego, CA, USA
| | | | - Marcos Intaglietta
- Department of Bioengineering, University of California, San Diego, CA, USA
| | - Ruy Pérez-Tamayo
- Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico
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28
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Abstract
In the lung, acute reductions in oxygen lead to hypoxic pulmonary vasoconstriction, whereas prolonged exposures to hypoxia result in sustained vasoconstriction, pulmonary vascular remodeling, and the development of pulmonary hypertension. Data from both human subjects and animal models implicate a role for hypoxia-inducible factors (HIFs), oxygen-sensitive transcription factors, in pulmonary vascular responses to both acute and chronic hypoxia. In this review, we discuss work from our laboratory and others supporting a role for HIF in modulating hypoxic pulmonary vasoconstriction and mediating hypoxia-induced pulmonary hypertension, identify some of the downstream targets of HIF, and assess the potential to pharmacologically target the HIF system.
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Affiliation(s)
- Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
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29
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Li L, Howell K, Sands M, Banahan M, Frohlich S, Rowan SC, Neary R, Ryan D, McLoughlin P. The α and Δ isoforms of CREB1 are required to maintain normal pulmonary vascular resistance. PLoS One 2013; 8:e80637. [PMID: 24349008 PMCID: PMC3857174 DOI: 10.1371/journal.pone.0080637] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 10/05/2013] [Indexed: 01/15/2023] Open
Abstract
Chronic hypoxia causes pulmonary hypertension associated with structural alterations in pulmonary vessels and sustained vasoconstriction. The transcriptional mechanisms responsible for these distinctive changes are unclear. We have previously reported that CREB1 is activated in the lung in response to alveolar hypoxia but not in other organs. To directly investigate the role of α and Δ isoforms of CREB1 in the regulation of pulmonary vascular resistance we examined the responses of mice in which these isoforms of CREB1 had been inactivated by gene mutation, leaving only the β isoform intact (CREB(αΔ) mice). Here we report that expression of CREB regulated genes was altered in the lungs of CREB(αΔ) mice. CREB(αΔ) mice had greater pulmonary vascular resistance than wild types, both basally in normoxia and following exposure to hypoxic conditions for three weeks. There was no difference in rho kinase mediated vasoconstriction between CREB(αΔ) and wild type mice. Stereological analysis of pulmonary vascular structure showed characteristic wall thickening and lumen reduction in hypoxic wild-type mice, with similar changes observed in CREB(αΔ). CREB(αΔ) mice had larger lungs with reduced epithelial surface density suggesting increased pulmonary compliance. These findings show that α and Δ isoforms of CREB1 regulate homeostatic gene expression in the lung and that normal activity of these isoforms is essential to maintain low pulmonary vascular resistance in both normoxic and hypoxic conditions and to maintain the normal alveolar structure. Interventions that enhance the actions of α and Δ isoforms of CREB1 warrant further investigation in hypoxic lung diseases.
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Affiliation(s)
- Lili Li
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, Dublin, Ireland
| | - Katherine Howell
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, Dublin, Ireland
| | - Michelle Sands
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, Dublin, Ireland
| | - Mark Banahan
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, Dublin, Ireland
| | - Stephen Frohlich
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, Dublin, Ireland
- Department of Anaesthesia and Critical Care, St Vincent's University Hospital, Dublin, Ireland
| | - Simon C. Rowan
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, Dublin, Ireland
| | - Roisín Neary
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, Dublin, Ireland
| | - Donal Ryan
- Department of Anaesthesia and Critical Care, St Vincent's University Hospital, Dublin, Ireland
| | - Paul McLoughlin
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, Dublin, Ireland
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30
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Maarman G, Lecour S, Butrous G, Thienemann F, Sliwa K. A comprehensive review: the evolution of animal models in pulmonary hypertension research; are we there yet? Pulm Circ 2013; 3:739-56. [PMID: 25006392 PMCID: PMC4070827 DOI: 10.1086/674770] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 06/28/2013] [Indexed: 02/06/2023] Open
Abstract
Pulmonary hypertension (PH) is a disorder that develops as a result of remodeling of the pulmonary vasculature and is characterized by narrowing/obliteration of small pulmonary arteries, leading to increased mean pulmonary artery pressure and pulmonary vascular resistance. Subsequently, PH increases the right ventricular afterload, which leads to right ventricular hypertrophy and eventually right ventricular failure. The pathophysiology of PH is not fully elucidated, and current treatments have only a modest impact on patient survival and quality of life. Thus, there is an urgent need for improved treatments or a cure. The use of animal models has contributed extensively to the current understanding of PH pathophysiology and the investigation of experimental treatments. However, PH in current animal models may not fully represent current clinical observations. For example, PH in animal models appears to be curable with many therapeutic interventions, and the severity of PH in animal models is also believed to correlate poorly with that observed in humans. In this review, we discuss a variety of animal models in PH research, some of their contributions to the field, their shortcomings, and how these have been addressed. We highlight the fact that the constant development and evolution of animal models will help us to more closely model the severity and heterogeneity of PH observed in humans.
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Affiliation(s)
- Gerald Maarman
- Hatter Institute for Cardiovascular Research in Africa (HICRA), Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Sandrine Lecour
- Hatter Institute for Cardiovascular Research in Africa (HICRA), Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Ghazwan Butrous
- Pulmonary Vascular Research Institute, Kent Enterprise Hub, University of Kent, Canterbury, United Kingdom
| | - Friedrich Thienemann
- Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Karen Sliwa
- Hatter Institute for Cardiovascular Research in Africa (HICRA), Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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31
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Toba M, Alzoubi A, O'Neill KD, Gairhe S, Matsumoto Y, Oshima K, Abe K, Oka M, McMurtry IF. Temporal hemodynamic and histological progression in Sugen5416/hypoxia/normoxia-exposed pulmonary arterial hypertensive rats. Am J Physiol Heart Circ Physiol 2013; 306:H243-50. [PMID: 24240870 DOI: 10.1152/ajpheart.00728.2013] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have investigated the temporal relationship between the hemodynamic and histological/morphological progression in a rat model of pulmonary arterial hypertension that develops pulmonary arterial lesions morphologically indistinguishable from those in human pulmonary arterial hypertension. Adult male rats were injected with Sugen5416 and exposed to hypoxia for 3 wk followed by a return to normoxia for various additional weeks. At 1, 3, 5, 8, and 13 wk after the Sugen5416 injection, hemodynamic and histological examinations were performed. Right ventricular systolic pressure reached its maximum 5 wk after Sugen5416 injection and plateaued thereafter. Cardiac index decreased at the 3∼5-wk time point, and tended to further decline at later time points. Reflecting these changes, calculated total pulmonary resistance showed a pattern of progressive worsening. Acute intravenous fasudil markedly reduced the elevated pressure and resistance at all time points tested. The percentage of severely occluded small pulmonary arteries showed a similar pattern of progression to that of right ventricular systolic pressure. These small vessels were occluded predominantly with nonplexiform-type neointimal formation except for the 13-wk time point. There was no severe occlusion in larger arteries until the 13-wk time point, when significant numbers of vessels were occluded with plexiform-type neointima. The Sugen5416/hypoxia/normoxia-exposed rat shows a pattern of chronic hemodynamic progression similar to that observed in pulmonary arterial hypertension patients. In addition to vasoconstriction, nonplexiform-type neointimal occlusion of small arteries appears to contribute significantly to the early phase of pulmonary arterial hypertension development, and plexiform-type larger vessel occlusion may play a role in the late deterioration.
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Affiliation(s)
- Michie Toba
- Department of Pharmacology, University of South Alabama, Mobile, Alabama
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32
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He J, Li H, Li Y, Gui L, Mao X. Anomalous origin of the right pulmonary artery from the ascending aorta: successful correction in an adult patient. Herz 2013; 40:311-3. [PMID: 24154888 DOI: 10.1007/s00059-013-3993-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 09/16/2013] [Accepted: 09/20/2013] [Indexed: 11/30/2022]
Affiliation(s)
- J He
- Department of Cardiothoracic Surgery, The First People's Hospital of Yunnan Province, Kunming University of Science and Technology, Jingbi Road, No.157, 650051, Kunming, China
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33
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Jones RC, Capen DE. Alveolar oxygen tension and angio-architecture of the distal adult lung. Ultrastruct Pathol 2013; 37:395-407. [PMID: 24144043 DOI: 10.3109/01913123.2013.831156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The present study demonstrates the fine structure of pulmonary capillaries first injured and then undergoing growth in response to a change in the ambient alveolar oxygen tension. Breathing a high fraction of inspired oxygen (FiO2 0.75) triggers restriction by endothelial cell injury and effacement leading to segment narrowing and shortening and segment loss as demonstrated by a fall in density. Subsequently, breathing a relatively low fraction (FiO2 0.21) triggers capillary assembly (angiogenesis), which reverses the changes. The data underscore the structural reprogramming (reduction and restoration) of pulmonary capillaries in response to significant shifts in oxygen tension.
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Affiliation(s)
- Rosemary C Jones
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and
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34
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McLoughlin P, Ward JPT. Hypoxic pulmonary hypertension; the load on the right ventricle. Exp Physiol 2013; 98:1244-6. [DOI: 10.1113/expphysiol.2012.068940] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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35
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Wan J, Yamamura A, Zimnicka AM, Voiriot G, Smith KA, Tang H, Ayon RJ, Choudhury MSR, Ko EA, Wang J, Wang C, Makino A, Yuan JXJ. Chronic hypoxia selectively enhances L- and T-type voltage-dependent Ca2+ channel activity in pulmonary artery by upregulating Cav1.2 and Cav3.2. Am J Physiol Lung Cell Mol Physiol 2013; 305:L154-64. [PMID: 23686856 DOI: 10.1152/ajplung.00313.2012] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hypoxia-induced pulmonary hypertension (HPH) is characterized by sustained pulmonary vasoconstriction and vascular remodeling, both of which are mediated by pulmonary artery smooth muscle cell (PASMC) contraction and proliferation, respectively. An increase in cytosolic Ca²⁺ concentration ([Ca²⁺]cyt) is a major trigger for pulmonary vasoconstriction and an important stimulus for cell proliferation in PASMCs. Ca²⁺ influx through voltage-dependent Ca²⁺ channels (VDCC) is an important pathway for the regulation of [Ca²⁺]cyt. The potential role for L- and T-type VDCC in the development of HPH is still unclear. Using a hypoxic-induced pulmonary hypertension mouse model, we undertook this study to identify if VDCC in pulmonary artery (PA) are functionally upregulated and determine which type of VDCC are altered in HPH. Mice subjected to chronic hypoxia developed pulmonary hypertension within 4 wk, and high-K⁺- and U-46619-induced contraction of PA was greater in chronic hypoxic mice than that in normoxic control mice. Additionally, we demonstrate that high-K⁺- and U-46619-induced Ca²⁺ influx in PASMC is significantly increased in the hypoxic group. The VDCC activator, Bay K8864, induced greater contraction of the PA of hypoxic mice than in that of normoxic mice in isometric force measurements. L-type and T-type VDCC blockers significantly attenuated absolute contraction of the PA in hypoxic mice. Chronic hypoxia did not increase high-K⁺- and U-46619-induced contraction of mesenteric artery (MA). Compared with MA, PA displayed higher expression of calcium channel voltage-dependent L-type α1C-subunit (Cav1.2) and T-type α1H-subunit (Cav3.2) upon exposure to chronic hypoxia. In conclusion, both L-type and T-type VDCC were functionally upregulated in PA, but not MA, in HPH mice, which could result from selectively increased expression of Cav1.2 and Cav3.2.
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Affiliation(s)
- Jun Wan
- Department of Medicine, Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
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36
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Preston IR, Sagliani KD, Warburton RR, Hill NS, Fanburg BL, Jaffe IZ. Mineralocorticoid receptor antagonism attenuates experimental pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2013; 304:L678-88. [PMID: 23457185 DOI: 10.1152/ajplung.00300.2012] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mineralocorticoid receptor (MR) activation stimulates systemic vascular and left ventricular remodeling. We hypothesized that MR contributes to pulmonary vascular and right ventricular (RV) remodeling of pulmonary hypertension (PH). We evaluated the efficacy of MR antagonism by spironolactone in two experimental PH models; mouse chronic hypoxia-induced PH (prevention model) and rat monocrotaline-induced PH (prevention and treatment models). Last, the biological function of the MR was analyzed in cultured distal pulmonary artery smooth muscle cells (PASMCs). In hypoxic PH mice, spironolactone attenuated the increase in RV systolic pressure, pulmonary arterial muscularization, and RV fibrosis. In rat monocrotaline-induced PH (prevention arm), spironolactone attenuated pulmonary vascular resistance and pulmonary vascular remodeling. In the established disease (treatment arm), spironolactone decreased RV systolic pressure and pulmonary vascular resistance with no significant effect on histological measures of pulmonary vascular remodeling, or RV fibrosis. Spironolactone decreased RV cardiomyocyte size modestly with no significant effect on RV mass, systemic blood pressure, cardiac output, or body weight, suggesting a predominantly local pulmonary vascular effect. In distal PASMCs, MR was expressed and localized diffusely. Treatment with the MR agonist aldosterone, hypoxia, or platelet-derived growth factor promoted MR translocation to the nucleus, activated MR transcriptional function, and stimulated PASMC proliferation, while spironolactone blocked these effects. In summary, MR is active in distal PASMCs, and its antagonism prevents PASMC proliferation and attenuates experimental PH. These data suggest that MR is involved in the pathogenesis of PH via effects on PASMCs and that MR antagonism may represent a novel therapeutic target for this disease.
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Affiliation(s)
- Ioana R Preston
- Tupper Research Institute and Pulmonary, Critical Care and Sleep Division, Tufts Medical Center, Boston, MA 02111, USA.
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37
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Voelkel NF, Mizuno S, Bogaard HJ. The role of hypoxia in pulmonary vascular diseases: a perspective. Am J Physiol Lung Cell Mol Physiol 2013; 304:L457-65. [PMID: 23377344 DOI: 10.1152/ajplung.00335.2012] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
From the discovery of hypoxic pulmonary vasoconstriction, responses to hypoxia have been considered as representative for the many alterations in lung vessels that occur in several chronic lung diseases, including pulmonary hypertension, interstitial pulmonary fibrosis, acute respiratory distress syndrome, and chronic obstructive pulmonary disease. An essential part of preclinical research to explain the pathobiology of these diseases has been centered on the exposure of small and large animals to hypoxia. This review aims to summarize pivotal results of clinical and preclinical research on hypoxia, which still have important implications for researchers today.
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Affiliation(s)
- Norbert F Voelkel
- Victoria Johnson Laboratory for Lung Research, Pulmonary and Critical Care Medicine Division, Virginia Commonwealth University, Richmond, VA, USA
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