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Macias D, Moore S, Crosby A, Southwood M, Du X, Tan H, Xie S, Vassallo A, Wood AJT, Wallace EM, Cowburn AS. Targeting HIF2α-ARNT hetero-dimerisation as a novel therapeutic strategy for pulmonary arterial hypertension. Eur Respir J 2021; 57:13993003.02061-2019. [PMID: 32972983 PMCID: PMC7930471 DOI: 10.1183/13993003.02061-2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 08/26/2020] [Indexed: 12/13/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a destructive disease of the pulmonary vasculature often leading to right heart failure and death. Current therapeutic intervention strategies only slow disease progression. The role of aberrant hypoxia-inducible factor (HIF)2α stability and function in the initiation and development of pulmonary hypertension (PH) has been an area of intense interest for nearly two decades.Here we determine the effect of a novel HIF2α inhibitor (PT2567) on PH disease initiation and progression, using two pre-clinical models of PH. Haemodynamic measurements were performed, followed by collection of heart, lung and blood for pathological, gene expression and biochemical analysis. Blood outgrowth endothelial cells from idiopathic PAH patients were used to determine the impact of HIF2α-inhibition on endothelial function.Global inhibition of HIF2a reduced pulmonary vascular haemodynamics and pulmonary vascular remodelling in both su5416/hypoxia prevention and intervention models. PT2567 intervention reduced the expression of PH-associated target genes in both lung and cardiac tissues and restored plasma nitrite concentration. Treatment of monocrotaline-exposed rodents with PT2567 reduced the impact on cardiovascular haemodynamics and promoted a survival advantage. In vitro, loss of HIF2α signalling in human pulmonary arterial endothelial cells suppresses target genes associated with inflammation, and PT2567 reduced the hyperproliferative phenotype and overactive arginase activity in blood outgrowth endothelial cells from idiopathic PAH patients. These data suggest that targeting HIF2α hetero-dimerisation with an orally bioavailable compound could offer a new therapeutic approach for PAH. Future studies are required to determine the role of HIF in the heterogeneous PAH population.
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Affiliation(s)
- David Macias
- CRUK Cambridge Centre Early Detection Programme, Dept of Oncology, Hutchison/MRC Research Centre, University of Cambridge, Cambridge, UK.,Both authors contributed equally
| | - Stephen Moore
- Dept of Medicine, University of Cambridge, Cambridge, UK.,Both authors contributed equally
| | - Alexi Crosby
- Dept of Medicine, University of Cambridge, Cambridge, UK
| | - Mark Southwood
- Dept of Pathology, Papworth Hospital National Health Service Foundation Trust, Cambridge, UK
| | - Xinlin Du
- Peloton Therapeutics Inc. (a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA), Dallas, TX, USA
| | - Huiling Tan
- Peloton Therapeutics Inc. (a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA), Dallas, TX, USA
| | - Shanhai Xie
- Peloton Therapeutics Inc. (a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA), Dallas, TX, USA
| | | | | | - Eli M Wallace
- Peloton Therapeutics Inc. (a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA), Dallas, TX, USA
| | - Andrew S Cowburn
- Dept of Medicine, University of Cambridge, Cambridge, UK .,National Heart and Lung Institute, Imperial College London, London, UK
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Cameron J, Crosby A, Paszkowski C, Bayne E. Visual spectrogram scanning paired with an observation–confirmation occupancy model improves the efficiency and accuracy of bioacoustic anuran data. CAN J ZOOL 2020. [DOI: 10.1139/cjz-2020-0103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Passive acoustic monitoring using autonomous recording units has improved anuran amphibian call survey data collection. A challenge associated with this approach is the time required for audio data processing. Our objective was to develop a more efficient method of processing and analyzing acoustic data through visual spectrogram scanning and the application of an observation–confirmation occupancy model. We compared detection rates between methods of standard recording listening and visually scanning spectrogram images using different spectrogram parameters. Relative to listening, we found that 1 min spectrograms in two 30 s frames yield the best time efficiency–accuracy trade-off. A standard occupancy model applied to visual scanning data underestimated occupancy estimates relative to listening data for three species and overestimated occupancy for one species. The observation–confirmation model used a subset of listening data to improve the estimates of detection probability from visual scanning and therefore reduced bias in occupancy estimates when compared with using visual scanning data alone. Overall, the combination of the visual scanning method and the observation–confirmation model allowed us to maintain the accuracy of occupancy estimates while greatly increasing the efficiency of anuran data processing. These methods are widely applicable and can increase sample size and precision for acoustic monitoring programs using autonomous recording units.
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Affiliation(s)
- J. Cameron
- Department of Biological Sciences, University of Alberta, CW405, Biological Science Building, Edmonton, AB T6G 2R3, Canada
| | - A. Crosby
- Department of Biological Sciences, University of Alberta, CW405, Biological Science Building, Edmonton, AB T6G 2R3, Canada
- Department of Biological Sciences, University of Alberta, CW405, Biological Science Building, Edmonton, AB T6G 2R3, Canada
| | - C. Paszkowski
- Department of Biological Sciences, University of Alberta, CW405, Biological Science Building, Edmonton, AB T6G 2R3, Canada
- Department of Biological Sciences, University of Alberta, CW405, Biological Science Building, Edmonton, AB T6G 2R3, Canada
| | - E. Bayne
- Department of Biological Sciences, University of Alberta, CW405, Biological Science Building, Edmonton, AB T6G 2R3, Canada
- Department of Biological Sciences, University of Alberta, CW405, Biological Science Building, Edmonton, AB T6G 2R3, Canada
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3
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Dunmore BJ, Yang X, Crosby A, Moore S, Long L, Huang C, Southwood M, Austin ED, Rana A, Upton PD, Morrell NW. 4PBA Restores Signaling of a Cysteine-substituted Mutant BMPR2 Receptor Found in Patients with Pulmonary Arterial Hypertension. Am J Respir Cell Mol Biol 2020; 63:160-171. [PMID: 32255665 DOI: 10.1165/rcmb.2019-0321oc] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Mutations in the gene encoding BMPR2 (bone morphogenetic protein type 2 receptor) are the major cause of heritable pulmonary arterial hypertension (PAH). Point mutations in the BMPR2 ligand-binding domain involving cysteine residues (such as C118W) are causative of PAH and predicted to cause protein misfolding. Using heterologous overexpression systems, we showed previously that these mutations lead to retention of BMPR2 in the endoplasmic reticulum but are partially rescued by chemical chaperones. Here, we sought to determine whether the chemical chaperone 4-phenylbutyrate (4PBA) restores BMPR2 signaling in primary cells and in a knockin mouse harboring a C118W mutation. First, we confirmed dysfunctional BMP signaling in dermal fibroblasts isolated from a family with PAH segregating the BMPR2 C118W mutation. After BMP4 treatment, the induction of downstream signaling targets (Smad1/5, ID1 [inhibitor of DNA binding 1], and ID2) was significantly reduced in C118W mutant cells. Treatment with 4PBA significantly rescued Smad1/5, ID1, and ID2 expression. Pulmonary artery smooth muscle cells isolated from the lungs of heterozygous mice harboring the Bmpr2 C118W mutation exhibited significantly increased proliferation. In the presence of 4PBA, hyperproliferation was dramatically reduced. Furthermore, in vivo, 4PBA treatment of Bmpr2 C118W mice partially rescued Bmpr2 expression, restored downstream signaling, and improved vascular remodeling. These findings demonstrate in primary cells and in a knockin mouse that the repurposed small-molecule chemical chaperone 4PBA might be a promising precision medicine approach to treat PAH in patients with specific subtypes of BMPR2 mutation involving cysteine substitutions in the ligand-binding domain.
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Affiliation(s)
- Benjamin J Dunmore
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
| | - XuDong Yang
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
| | - Alexi Crosby
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
| | - Stephen Moore
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
| | - Lu Long
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
| | - Christopher Huang
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
| | - Mark Southwood
- Pathology Research, Royal Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom; and
| | - Eric D Austin
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Amer Rana
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
| | - Paul D Upton
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
| | - Nicholas W Morrell
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's and Royal Papworth Hospitals, Cambridge, United Kingdom
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Long L, Yang X, Southwood M, Moore S, Crosby A, Upton PD, Dunmore BJ, Morrell NW. Targeting translational read-through of premature termination mutations in BMPR2 with PTC124 for pulmonary arterial hypertension. Pulm Circ 2020; 10:2045894020935783. [PMID: 32733669 PMCID: PMC7372630 DOI: 10.1177/2045894020935783] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 05/28/2020] [Indexed: 02/02/2023] Open
Abstract
Pulmonary arterial hypertension is a fatal disorder of the lung circulation in which accumulation of vascular cells progressively obliterates the pulmonary arterioles. This results in sustained elevation in pulmonary artery pressure leading eventually to right heart failure. Approximately, 80% of familial and 20% of sporadic idiopathic pulmonary arterial hypertension cases are caused by mutations in the bone morphogenetic protein receptor type 2 (BMPR2). Nonsense mutations in BMPR2 are amongst the most common mutations found, where the insertion of a premature termination codon causes mRNA degradation via activation of the nonsense-mediated decay pathway leading to a state of haploinsufficiency. Ataluren (PTC124), a compound that permits ribosomal read-through of premature stop codons, has been previously reported to increase BMPR2 protein expression in cells derived from pulmonary arterial hypertension patients harbouring nonsense mutations. In this study, we characterised the effects of PTC124 on a range of nonsense BMPR2 mutations, focusing on the R584X mutation both in vitro and in vivo. Treatment with PTC124 partially restored BMPR2 protein expression in blood outgrowth endothelial cells isolated from a patient harbouring the R584X mutation. Furthermore, a downstream bone morphogenetic protein signalling target, Id1, was rescued by PTC124 treatment. Mutant cells also exhibited increased lipopolysaccharide-induced permeability, which was reversed by PTC124 treatment. Increased proliferation and apoptosis in R584X blood outgrowth endothelial cells were also significantly reduced by PTC124. Moreover, oral PTC124 increased lung BMPR2 protein expression in mice harbouring the R584X mutation (Bmpr2 +/R584X ). Our findings provide support for future experimental medicine studies of PTC124 in pulmonary arterial hypertension patients with specific nonsense BMPR2 mutations.
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Affiliation(s)
- Lu Long
- Department of Medicine, University of
Cambridge School of Clinical Medicine, Cambridge, UK
| | - Xudong Yang
- Department of Medicine, University of
Cambridge School of Clinical Medicine, Cambridge, UK
| | - Mark Southwood
- Pathology Research, Royal Papworth
Hospital NHS Foundation Trust, Cambridge, UK
| | - Stephen Moore
- Department of Medicine, University of
Cambridge School of Clinical Medicine, Cambridge, UK
| | - Alexi Crosby
- Department of Medicine, University of
Cambridge School of Clinical Medicine, Cambridge, UK
| | - Paul D. Upton
- Department of Medicine, University of
Cambridge School of Clinical Medicine, Cambridge, UK
| | - Benjamin J. Dunmore
- Department of Medicine, University of
Cambridge School of Clinical Medicine, Cambridge, UK
| | - Nicholas W. Morrell
- Department of Medicine, University of
Cambridge School of Clinical Medicine, Cambridge, UK,Nicholas W. Morrell, Division of Respiratory
Medicine, Department of Medicine, Box 157, Addenbrooke's Hospital, Hills Road,
Cambridge CB2 0QQ, United Kingdom.
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5
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Connolly M, Garfield BE, Crosby A, Morrell NW, Wort SJ, Kemp PR. miR-1-5p targets TGF-βR1 and is suppressed in the hypertrophying hearts of rats with pulmonary arterial hypertension. PLoS One 2020; 15:e0229409. [PMID: 32109943 PMCID: PMC7048278 DOI: 10.1371/journal.pone.0229409] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/05/2020] [Indexed: 01/09/2023] Open
Abstract
The microRNA miR-1 is an important regulator of muscle phenotype including cardiac muscle. Down-regulation of miR-1 has been shown to occur in left ventricular hypertrophy but its contribution to right ventricular hypertrophy in pulmonary arterial hypertension are not known. Previous studies have suggested that miR-1 may suppress transforming growth factor-beta (TGF-β) signalling, an important pro-hypertrophic pathway but only indirect mechanisms of regulation have been identified. We identified the TGF-β type 1 receptor (TGF-βR1) as a putative miR-1 target. We therefore hypothesized that miR-1 and TGF-βR1 expression would be inversely correlated in hypertrophying right ventricle of rats with pulmonary arterial hypertension and that miR-1 would inhibit TGF-β signalling by targeting TGF-βR1 expression. Quantification of miR-1 and TGF-βR1 in rats treated with monocrotaline to induce pulmonary arterial hypertension showed appropriate changes in miR-1 and TGF-βR1 expression in the hypertrophying right ventricle. A miR-1-mimic reduced enhanced green fluorescent protein expression from a reporter vector containing the TGF-βR1 3’- untranslated region and knocked down endogenous TGF-βR1. Lastly, miR-1 reduced TGF-β activation of a (mothers against decapentaplegic homolog) SMAD2/3-dependent reporter. Taken together, these data suggest that miR-1 targets TGF-βR1 and reduces TGF-β signalling, so a reduction in miR-1 expression may increase TGF-β signalling and contribute to cardiac hypertrophy.
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Affiliation(s)
- Martin Connolly
- Molecular Medicine, National Heart & Lung Institute, Imperial College London, London, United Kingdom
| | - Benjamin E. Garfield
- Molecular Medicine, National Heart & Lung Institute, Imperial College London, London, United Kingdom
- National Pulmonary Hypertension Centre at the Royal Brompton and Harefield NHS Trust and National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Alexi Crosby
- Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Nick W. Morrell
- Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Stephen J. Wort
- National Pulmonary Hypertension Centre at the Royal Brompton and Harefield NHS Trust and National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Paul R. Kemp
- Molecular Medicine, National Heart & Lung Institute, Imperial College London, London, United Kingdom
- * E-mail:
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6
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Yang P, Read C, Kuc RE, Nyimanu D, Williams TL, Crosby A, Buonincontri G, Southwood M, Sawiak SJ, Glen RC, Morrell NW, Davenport AP, Maguire JJ. A novel cyclic biased agonist of the apelin receptor, MM07, is disease modifying in the rat monocrotaline model of pulmonary arterial hypertension. Br J Pharmacol 2019; 176:1206-1221. [PMID: 30710493 PMCID: PMC6468262 DOI: 10.1111/bph.14603] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 01/10/2019] [Accepted: 01/23/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Apelin is an endogenous vasodilatory and inotropic peptide that is down-regulated in human pulmonary arterial hypertension, although the density of the apelin receptor is not significantly attenuated. We hypothesised that a G protein-biased apelin analogue MM07, which is more stable than the endogenous apelin peptide, may be beneficial in this condition with the advantage of reduced β-arrestin-mediated receptor internalisation with chronic use. EXPERIMENTAL APPROACH Male Sprague-Dawley rats received either monocrotaline to induce pulmonary arterial hypertension or saline and then daily i.p. injections of either MM07 or saline for 21 days. The extent of disease was assessed by right ventricular catheterisation, cardiac MRI, and histological analysis of the pulmonary vasculature. The effect of MM07 on signalling, proliferation, and apoptosis of human pulmonary artery endothelial cells was investigated. KEY RESULTS MM07 significantly reduced the elevation of right ventricular systolic pressure and hypertrophy induced by monocrotaline. Monocrotaline-induced changes in cardiac structure and function, including right ventricular end-systolic and end-diastolic volumes, ejection fraction, and left ventricular end-diastolic volume, were attenuated by MM07. MM07 also significantly reduced monocrotaline-induced muscularisation of small pulmonary blood vessels. MM07 stimulated endothelial NOS phosphorylation and expression, promoted proliferation, and attenuated apoptosis of human pulmonary arterial endothelial cells in vitro. CONCLUSION AND IMPLICATIONS Our findings suggest that chronic treatment with MM07 is beneficial in this animal model of pulmonary arterial hypertension by addressing disease aetiology. These data support the development of G protein-biased apelin receptor agonists with improved pharmacokinetic profiles for use in human disease.
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Affiliation(s)
- Peiran Yang
- Experimental Medicine and ImmunotherapeuticsUniversity of CambridgeCambridgeUK
| | - Cai Read
- Experimental Medicine and ImmunotherapeuticsUniversity of CambridgeCambridgeUK
| | - Rhoda E. Kuc
- Experimental Medicine and ImmunotherapeuticsUniversity of CambridgeCambridgeUK
| | - Duuamene Nyimanu
- Experimental Medicine and ImmunotherapeuticsUniversity of CambridgeCambridgeUK
| | - Thomas L. Williams
- Experimental Medicine and ImmunotherapeuticsUniversity of CambridgeCambridgeUK
| | - Alexi Crosby
- Department of MedicineUniversity of CambridgeCambridgeUK
| | - Guido Buonincontri
- Wolfson Brain Imaging Centre, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Mark Southwood
- Department of PathologyPapworth Hospital NHS Foundation TrustCambridgeUK
| | - Stephen J. Sawiak
- Wolfson Brain Imaging Centre, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Robert C. Glen
- The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, CambridgeUK and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College LondonUK
| | | | | | - Janet J. Maguire
- Experimental Medicine and ImmunotherapeuticsUniversity of CambridgeCambridgeUK
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7
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Garfield BE, Crosby A, Shao D, Yang P, Read C, Sawiak S, Moore S, Parfitt L, Harries C, Rice M, Paul R, Ormiston ML, Morrell NW, Polkey MI, Wort SJ, Kemp PR. Growth/differentiation factor 15 causes TGFβ-activated kinase 1-dependent muscle atrophy in pulmonary arterial hypertension. Thorax 2019; 74:164-176. [PMID: 30554141 PMCID: PMC6467240 DOI: 10.1136/thoraxjnl-2017-211440] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 09/24/2018] [Accepted: 10/01/2018] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Skeletal muscle dysfunction is a clinically important complication of pulmonary arterial hypertension (PAH). Growth/differentiation factor 15 (GDF-15), a prognostic marker in PAH, has been associated with muscle loss in other conditions. We aimed to define the associations of GDF-15 and muscle wasting in PAH, to assess its utility as a biomarker of muscle loss and to investigate its downstream signalling pathway as a therapeutic target. METHODS GDF-15 levels and measures of muscle size and strength were analysed in the monocrotaline (MCT) rat, Sugen/hypoxia mouse and in 30 patients with PAH. In C2C12 myotubes the downstream targets of GDF-15 were identified. The pathway elucidated was then antagonised in vivo. RESULTS Circulating GDF-15 levels correlated with tibialis anterior (TA) muscle fibre diameter in the MCT rat (Pearson r=-0.61, p=0.003). In patients with PAH, plasma GDF-15 levels of <564 pg/L predicted those with preserved muscle strength with a sensitivity and specificity of ≥80%. In vitro GDF-15 stimulated an increase in phosphorylation of TGFβ-activated kinase 1 (TAK1). Antagonising TAK1, with 5(Z)-7-oxozeaenol, in vitro and in vivo led to an increase in fibre diameter and a reduction in mRNA expression of atrogin-1 in both C2C12 cells and in the TA of animals who continued to grow. Circulating GDF-15 levels were also reduced in those animals which responded to treatment. CONCLUSIONS Circulating GDF-15 is a biomarker of muscle loss in PAH that is responsive to treatment. TAK1 inhibition shows promise as a method by which muscle atrophy may be directly prevented in PAH. TRIAL REGISTRATION NUMBER NCT01847716; Results.
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Affiliation(s)
- Benjamin E Garfield
- National Heart and Lung Institute, Imperial College London, London, UK
- National Pulmonary Hypertension Service, Royal Brompton Hospital, London, UK
| | - Alexi Crosby
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Dongmin Shao
- National Heart and Lung Institute, Imperial College London, London, UK
- National Pulmonary Hypertension Service, Royal Brompton Hospital, London, UK
| | - Peiran Yang
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Cai Read
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Steven Sawiak
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Stephen Moore
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Lisa Parfitt
- National Pulmonary Hypertension Service, Royal Brompton Hospital, London, UK
| | - Carl Harries
- National Pulmonary Hypertension Service, Royal Brompton Hospital, London, UK
| | - Martin Rice
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Richard Paul
- NIHR Respiratory Biomedical Research Unit at the Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, London, UK
| | - Mark L Ormiston
- Departments of Biomedical and Molecular Sciences, Medicine and Surgery, Queen's University, Kingston, Ontario, Canada
| | - Nicholas W Morrell
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Michael I Polkey
- NIHR Respiratory Biomedical Research Unit at the Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, London, UK
| | - Stephen John Wort
- National Heart and Lung Institute, Imperial College London, London, UK
- National Pulmonary Hypertension Service, Royal Brompton Hospital, London, UK
| | - Paul R Kemp
- National Heart and Lung Institute, Imperial College London, London, UK
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Crosby A, Toshner MR, Southwood MR, Soon E, Dunmore BJ, Groves E, Moore S, Wright P, Ottersbach K, Bennett C, Guerrero J, Ghevaert C, Morrell NW. Hematopoietic stem cell transplantation alters susceptibility to pulmonary hypertension in Bmpr2-deficient mice. Pulm Circ 2018; 8:2045894018801642. [PMID: 30160594 PMCID: PMC6144516 DOI: 10.1177/2045894018801642] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/27/2018] [Indexed: 02/02/2023] Open
Abstract
Increasing evidence suggests that patients with pulmonary arterial hypertension (PAH) demonstrate abnormalities in the bone marrow (BM) and hematopoietic progenitor cells. In addition, PAH is associated with myeloproliferative diseases. We have previously demonstrated that low-dose lipopolysaccharide (LPS) is a potent stimulus for the development of PAH in the context of a genetic PAH mouse model of BMPR2 dysfunction. We hypothesized that the hematopoietic progenitor cells might be driving disease in this model. To test this hypothesis, we performed adoptive transfer of BM between wild-type (Ctrl) and heterozygous Bmpr2 null (Mut) mice. Sixteen weeks after BM reconstitution, mice were exposed to low-dose chronic LPS (0.5 mg/kg three times a week for six weeks). Mice underwent right heart catheterization and tissues were removed for histology. After chronic LPS dosing, Ctrl mice in receipt of Mut BM developed PAH, whereas Mut mice receiving Ctrl BM were protected from PAH. BM histology demonstrated an increase in megakaryocytes and there was an increase in circulating platelets in Ctrl mice receiving Mut BM. These findings demonstrate that the hematopoietic stem cell compartment is involved in the susceptibility to PAH in the Mut mouse. The results raise the possibility that hematopoietic stem cell transplantation might be a potential treatment strategy in genetic forms of PAH.
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Affiliation(s)
- Alexi Crosby
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
| | - Mark R. Toshner
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
| | | | - Elaine Soon
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
| | - Benjamin J. Dunmore
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
| | - Emily Groves
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
| | - Stephen Moore
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
| | | | - Katrin Ottersbach
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Cavan Bennett
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, UK
| | - Jose Guerrero
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, UK
| | - Cedric Ghevaert
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, UK
| | - Nicholas W. Morrell
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
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9
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Connolly M, Garfield BE, Crosby A, Morrell NW, Wort SJ, Kemp PR. miR-322-5p targets IGF-1 and is suppressed in the heart of rats with pulmonary hypertension. FEBS Open Bio 2018; 8:339-348. [PMID: 29511611 PMCID: PMC5832985 DOI: 10.1002/2211-5463.12369] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/09/2017] [Accepted: 12/10/2017] [Indexed: 01/05/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is characterised by remodelling of the pulmonary vasculature leading to right ventricular hypertrophy. Here, we show that miR‐322‐5p (the rodent orthologue of miR‐424‐5p) expression is decreased in the right ventricle of monocrotaline‐treated rats, a model of PAH, whereas a putative target insulin‐like growth factor 1 (IGF‐1) is increased. IGF‐1 mRNA was enriched 16‐fold in RNA immunoprecipitated with Ago2, indicating binding to miR‐322‐5p. In cell transfection experiments, miR‐322‐5p suppressed the activity of a luciferase reporter containing a section of the IGF‐1 3′ untranslated region (UTR) as well as IGF‐1 mRNA and protein levels. Taken together, these data suggest that miR‐322 targets IGF‐1, a process downregulated in PAH‐related RV hypertrophy.
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Affiliation(s)
- Martin Connolly
- Molecular Medicine National Heart & Lung Institute Imperial College London UK
| | - Benjamin E Garfield
- Molecular Medicine National Heart & Lung Institute Imperial College London UK.,National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College London UK
| | - Alexi Crosby
- Department of Medicine Addenbrookes Hospital University of Cambridge UK
| | - Nick W Morrell
- Department of Medicine Addenbrookes Hospital University of Cambridge UK
| | - Stephen J Wort
- National Institute for Health Research Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College London UK
| | - Paul R Kemp
- Molecular Medicine National Heart & Lung Institute Imperial College London UK
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Yang P, Read C, Kuc RE, Buonincontri G, Southwood M, Torella R, Upton PD, Crosby A, Sawiak SJ, Carpenter TA, Glen RC, Morrell NW, Maguire JJ, Davenport AP. Elabela/Toddler Is an Endogenous Agonist of the Apelin APJ Receptor in the Adult Cardiovascular System, and Exogenous Administration of the Peptide Compensates for the Downregulation of Its Expression in Pulmonary Arterial Hypertension. Circulation 2017; 135:1160-1173. [PMID: 28137936 PMCID: PMC5363837 DOI: 10.1161/circulationaha.116.023218] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 01/17/2017] [Indexed: 01/15/2023]
Abstract
Supplemental Digital Content is available in the text. Background: Elabela/toddler (ELA) is a critical cardiac developmental peptide that acts through the G-protein–coupled apelin receptor, despite lack of sequence similarity to the established ligand apelin. Our aim was to investigate the receptor pharmacology, expression pattern, and in vivo function of ELA peptides in the adult cardiovascular system, to seek evidence for alteration in pulmonary arterial hypertension (PAH) in which apelin signaling is downregulated, and to demonstrate attenuation of PAH severity with exogenous administration of ELA in a rat model. Methods: In silico docking analysis, competition binding experiments, and downstream assays were used to characterize ELA receptor binding in human heart and signaling in cells expressing the apelin receptor. ELA expression in human cardiovascular tissues and plasma was determined using real-time quantitative polymerase chain reaction, dual-labeling immunofluorescent staining, and immunoassays. Acute cardiac effects of ELA-32 and [Pyr1]apelin-13 were assessed by MRI and cardiac catheterization in anesthetized rats. Cardiopulmonary human and rat tissues from PAH patients and monocrotaline- and Sugen/hypoxia-exposed rats were used to show changes in ELA expression in PAH. The effect of ELA treatment on cardiopulmonary remodeling in PAH was investigated in the monocrotaline rat model. Results: ELA competed for binding of apelin in human heart with overlap for the 2 peptides indicated by in silico modeling. ELA activated G-protein– and β-arrestin–dependent pathways. We detected ELA expression in human vascular endothelium and plasma. Comparable to apelin, ELA increased cardiac contractility, ejection fraction, and cardiac output and elicited vasodilatation in rat in vivo. ELA expression was reduced in cardiopulmonary tissues from PAH patients and PAH rat models, respectively. ELA treatment significantly attenuated elevation of right ventricular systolic pressure and right ventricular hypertrophy and pulmonary vascular remodeling in monocrotaline-exposed rats. Conclusions: These results show that ELA is an endogenous agonist of the human apelin receptor, exhibits a cardiovascular profile comparable to apelin, and is downregulated in human disease and rodent PAH models, and exogenous peptide can reduce the severity of cardiopulmonary remodeling and function in PAH in rats. This study provides additional proof of principle that an apelin receptor agonist may be of therapeutic use in PAH in humans.
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Affiliation(s)
- Peiran Yang
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Cai Read
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Rhoda E Kuc
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Guido Buonincontri
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Mark Southwood
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Rubben Torella
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Paul D Upton
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Alexi Crosby
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Stephen J Sawiak
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - T Adrian Carpenter
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Robert C Glen
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Nicholas W Morrell
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Janet J Maguire
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.)
| | - Anthony P Davenport
- From Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, UK (P.Y., C.R., R.E.K., J.J.M., A.P.D.); Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, University of Cambridge, UK (G.B., S.J.S., T.A.C.); Department of Pathology, Papworth Hospital, Papworth Everard, Cambridge, UK (M.S.); Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, UK (R.T., R.C.G.); Department of Medicine, University of Cambridge, Addenbrooke's Hospital, UK (P.D.U., A.C., N.W.M.); and Biomolecular Medicine, Department of Surgery and Cancer, Imperial College, London, UK (R.C.G.).
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Soon E, Crosby A, Southwood M, Moore S, Ron D, Marciniak S, Morrell NW. S83 Investigating the role of GCN2 in the pathogenesis of pulmonary hypertension. Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Crosby A, Soon E, Southwood M, Dunmore BJ, Toshner M, Morrell NW. S82 Bone marrow transplantation reduces susceptibility to pulmonary hypertension in BMPR2 deficient mice. Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.88] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Appleby SL, Mitrofan CG, Crosby A, Hoenderdos K, Lodge K, Upton PD, Yates CM, Nash GB, Chilvers ER, Morrell NW. Bone Morphogenetic Protein 9 Enhances Lipopolysaccharide-Induced Leukocyte Recruitment to the Vascular Endothelium. J Immunol 2016; 197:3302-3314. [PMID: 27647829 DOI: 10.4049/jimmunol.1601219] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 08/18/2016] [Indexed: 12/11/2022]
Abstract
Bone morphogenetic protein (BMP)9 is a circulating growth factor that is part of the TGF-β superfamily and is an essential regulator of vascular endothelial homeostasis. Previous studies have suggested a role for BMP9 signaling in leukocyte recruitment to the endothelium, but the directionality of this effect and underlying mechanisms have not been elucidated. In this study, we report that BMP9 upregulates TLR4 expression in human endothelial cells and that BMP9 pretreatment synergistically increases human neutrophil recruitment to LPS-stimulated human endothelial monolayers in an in vitro flow adhesion assay. BMP9 alone did not induce neutrophil recruitment to the endothelium. We also show that E-selectin and VCAM-1, but not ICAM-1, are upregulated in response to BMP9 in LPS-stimulated human endothelial cells. Small interfering RNA knockdown of activin receptor-like kinase 1 inhibited the BMP9-induced expression of TLR4 and VCAM-1 and inhibited BMP9-induced human neutrophil recruitment to LPS-stimulated human endothelial cells. BMP9 treatment also increased leukocyte recruitment within the pulmonary circulation in a mouse acute endotoxemia model. These results demonstrate that although BMP9 alone does not influence leukocyte recruitment, it primes the vascular endothelium to mount a more intense response when challenged with LPS through an increase in TLR4, E-selectin, and VCAM-1 and ultimately through enhanced leukocyte recruitment.
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Affiliation(s)
- Sarah L Appleby
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | | | - Alexi Crosby
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Kim Hoenderdos
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Katharine Lodge
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Paul D Upton
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Clara M Yates
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Gerard B Nash
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Edwin R Chilvers
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Nicholas W Morrell
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, UK
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14
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Crosby A, Soon E, Jones FM, Southwood MR, Haghighat L, Toshner MR, Raine T, Horan I, Yang P, Moore S, Ferrer E, Wright P, Ormiston ML, White RJ, Haight DA, Dunne DW, Morrell NW. Hepatic Shunting of Eggs and Pulmonary Vascular Remodeling in Bmpr2(+/-) Mice with Schistosomiasis. Am J Respir Crit Care Med 2016; 192:1355-65. [PMID: 26308618 DOI: 10.1164/rccm.201412-2262oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Schistosomiasis is a major cause of pulmonary arterial hypertension (PAH). Mutations in the bone morphogenetic protein type-II receptor (BMPR-II) are the commonest genetic cause of PAH. OBJECTIVES To determine whether Bmpr2(+/-) mice are more susceptible to schistosomiasis-induced pulmonary vascular remodeling. METHODS Wild-type (WT) and Bmpr2(+/-) mice were infected percutaneously with Schistosoma mansoni. At 17 weeks postinfection, right ventricular systolic pressure and liver and lung egg counts were measured. Serum, lung and liver cytokine, pulmonary vascular remodeling, and liver histology were assessed. MEASUREMENTS AND MAIN RESULTS By 17 weeks postinfection, there was a significant increase in pulmonary vascular remodeling in infected mice. This was greater in Bmpr2(+/-) mice and was associated with an increase in egg deposition and cytokine expression, which induced pulmonary arterial smooth muscle cell proliferation, in the lungs of these mice. Interestingly, Bmpr2(+/-) mice demonstrated dilatation of the hepatic central vein at baseline and postinfection, compared with WT. Bmpr2(+/-) mice also showed significant dilatation of the liver sinusoids and an increase in inflammatory cells surrounding the central hepatic vein, compared with WT. This is consistent with an increase in the transhepatic passage of eggs. CONCLUSIONS This study has shown that levels of BMPR-II expression modify the pulmonary vascular response to chronic schistosomiasis. The likely mechanism involves the increased passage of eggs to the lungs, caused by altered diameter of the hepatic veins and sinusoids in Bmpr2(+/-) mice. Genetically determined differences in the remodeling of hepatic vessels may represent a new risk factor for PAH associated with schistosomiasis.
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Affiliation(s)
- Alexi Crosby
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Elaine Soon
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Frances M Jones
- 2 Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Mark R Southwood
- 3 Department of Pathology, Papworth Hospital, Cambridge, United Kingdom
| | - Leila Haghighat
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Mark R Toshner
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Tim Raine
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Ian Horan
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Peiran Yang
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Stephen Moore
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Elisabet Ferrer
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Penny Wright
- 4 Addenbrooke's Hospital, Cambridge, United Kingdom; and
| | - Mark L Ormiston
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | | | | | - David W Dunne
- 2 Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Nicholas W Morrell
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
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Soon E, Crosby A, Southwood M, Yang P, Tajsic T, Toshner M, Appleby S, Shanahan CM, Bloch KD, Pepke-Zaba J, Upton P, Morrell NW. Bone morphogenetic protein receptor type II deficiency and increased inflammatory cytokine production. A gateway to pulmonary arterial hypertension. Am J Respir Crit Care Med 2016; 192:859-72. [PMID: 26073741 DOI: 10.1164/rccm.201408-1509oc] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Mutations in bone morphogenetic protein receptor type II (BMPR-II) underlie most cases of heritable pulmonary arterial hypertension (PAH). However, disease penetrance is only 20-30%, suggesting a requirement for additional triggers. Inflammation is emerging as a key disease-related factor in PAH, but to date there is no clear mechanism linking BMPR-II deficiency and inflammation. OBJECTIVES To establish a direct link between BMPR-II deficiency, a consequentially heightened inflammatory response, and development of PAH. METHODS We used pulmonary artery smooth muscle cells from Bmpr2(+/-) mice and patients with BMPR2 mutations and compared them with wild-type controls. For the in vivo model, we used mice heterozygous for a null allele in Bmpr2 (Bmpr2(+/-)) and wild-type littermates. MEASUREMENTS AND MAIN RESULTS Acute exposure to LPS increased lung and circulating IL-6 and KC (IL-8 analog) levels in Bmpr2(+/-) mice to a greater extent than in wild-type controls. Similarly, pulmonary artery smooth muscle cells from Bmpr2(+/-) mice and patients with BMPR2 mutations produced higher levels of IL-6 and KC/IL-8 after lipopolysaccharide stimulation compared with controls. BMPR-II deficiency in mouse and human pulmonary artery smooth muscle cells was associated with increased phospho-STAT3 and loss of extracellular superoxide dismutase. Chronic lipopolysaccharide administration caused pulmonary hypertension in Bmpr2(+/-) mice but not in wild-type littermates. Coadministration of tempol, a superoxide dismutase mimetic, ameliorated the exaggerated inflammatory response and prevented development of PAH. CONCLUSIONS This study demonstrates that BMPR-II deficiency promotes an exaggerated inflammatory response in vitro and in vivo, which can instigate development of pulmonary hypertension.
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Affiliation(s)
- Elaine Soon
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom.,2 Pulmonary Vascular Diseases Unit, Papworth Hospital, Cambridge, United Kingdom
| | - Alexi Crosby
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Mark Southwood
- 2 Pulmonary Vascular Diseases Unit, Papworth Hospital, Cambridge, United Kingdom
| | - Peiran Yang
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Tamara Tajsic
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom.,3 James Black Centre, Cardiovascular Division, King's College London, London, United Kingdom; and
| | - Mark Toshner
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Sarah Appleby
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Catherine M Shanahan
- 3 James Black Centre, Cardiovascular Division, King's College London, London, United Kingdom; and
| | - Kenneth D Bloch
- 4 Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts
| | - Joanna Pepke-Zaba
- 2 Pulmonary Vascular Diseases Unit, Papworth Hospital, Cambridge, United Kingdom
| | - Paul Upton
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Nicholas W Morrell
- 1 Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
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Cheng JPX, Mendoza-Topaz C, Howard G, Chadwick J, Shvets E, Cowburn AS, Dunmore BJ, Crosby A, Morrell NW, Nichols BJ. Caveolae protect endothelial cells from membrane rupture during increased cardiac output. J Cell Biol 2016; 211:53-61. [PMID: 26459598 PMCID: PMC4602045 DOI: 10.1083/jcb.201504042] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
This study provides direct in vivo evidence that endothelial cell caveolae disassemble and hence flatten out under increased mechanical stress and that the presence of caveolae protects endothelial cell plasma membranes from damage. Caveolae are strikingly abundant in endothelial cells, yet the physiological functions of caveolae in endothelium and other tissues remain incompletely understood. Previous studies suggest a mechanoprotective role, but whether this is relevant under the mechanical forces experienced by endothelial cells in vivo is unclear. In this study we have sought to determine whether endothelial caveolae disassemble under increased hemodynamic forces, and whether caveolae help prevent acute rupture of the plasma membrane under these conditions. Experiments in cultured cells established biochemical assays for disassembly of caveolar protein complexes, and assays for acute loss of plasma membrane integrity. In vivo, we demonstrate that caveolae in endothelial cells of the lung and cardiac muscle disassemble in response to acute increases in cardiac output. Electron microscopy and two-photon imaging reveal that the plasma membrane of microvascular endothelial cells in caveolin 1−/− mice is much more susceptible to acute rupture when cardiac output is increased. These data imply that mechanoprotection through disassembly of caveolae is important for endothelial function in vivo.
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Affiliation(s)
- Jade P X Cheng
- Medical Research Council, Laboratory of Molecular Biology, University of Cambridge, Cambridge CB2 1TN, UK
| | - Carolina Mendoza-Topaz
- Medical Research Council, Laboratory of Molecular Biology, University of Cambridge, Cambridge CB2 1TN, UK
| | - Gillian Howard
- Medical Research Council, Laboratory of Molecular Biology, University of Cambridge, Cambridge CB2 1TN, UK
| | - Jessica Chadwick
- Medical Research Council, Laboratory of Molecular Biology, University of Cambridge, Cambridge CB2 1TN, UK
| | - Elena Shvets
- Medical Research Council, Laboratory of Molecular Biology, University of Cambridge, Cambridge CB2 1TN, UK
| | - Andrew S Cowburn
- Department of Physiology, University of Cambridge, Cambridge CB2 1TN, UK
| | | | - Alexi Crosby
- Department of Medicine, University of Cambridge, Cambridge CB2 1TN, UK
| | | | - Benjamin J Nichols
- Medical Research Council, Laboratory of Molecular Biology, University of Cambridge, Cambridge CB2 1TN, UK
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Garfield B, Shao D, Crosby A, Yang P, Morrell N, Polkey M, Kemp P, Wort SJ. P268 The role of growth and differentiation factor 15 in smooth muscle cell proliferation in pulmonary hypertension. Thorax 2015. [DOI: 10.1136/thoraxjnl-2015-207770.404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Shao D, Garfied BE, Crosby A, Young P, Perros F, Humbert M, Adcock IM, Morrell N, Wort SJ. S6 The profiles of JMJD3, UTX and H3K27me3 expression in pulmonary vasculature in rat MCT model of PAH and human iPAH: implications for pulmonary arterial hypertension. Thorax 2015. [DOI: 10.1136/thoraxjnl-2015-207770.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Cheng JP, Mendoza-Topaz C, Howard G, Chadwick J, Shvets E, Cowburn AS, Dunmore BJ, Crosby A, Morrell NW, Nichols BJ. Caveolae protect endothelial cells from membrane rupture during increased cardiac output. J Gen Physiol 2015. [DOI: 10.1085/jgp.1465oia58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Cheng JP, Mendoza-Topaz C, Howard G, Chadwick J, Shvets E, Cowburn AS, Dunmore BJ, Crosby A, Morrell NW, Nichols BJ. Caveolae protect endothelial cells from membrane rupture during increased cardiac output. J Exp Med 2015. [DOI: 10.1084/jem.21211oia89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Soon E, Crosby A, Southwood M, Pepke-Zaba J, Upton P, Morrell N. BMPR-II mutations promote pulmonary arterial hypertension via a hyperinflammatory response. Clin Med (Lond) 2015; 15 Suppl 3:s15. [PMID: 26026008 DOI: 10.7861/clinmedicine.15-3-s15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Elaine Soon
- University of Cambridge, Cambridge, UK; Papworth Hospital NHS Trust, Cambridge, UK
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Crosby A, Soon E, Jones F, Southwood M, Haghighat L, Toshner M, Raine T, Horan I, Yang P, Davenport A, Moore S, Wright P, Dunne D, Morrell N. S34 Bmpr-ii Deficiency Leads To An Increase In Lung Egg Deposition, Pulmonary Vascular Remodelling And An Abnormal Liver Vasculature In Mice Chronically Infected With S. Mansoni. Thorax 2014. [DOI: 10.1136/thoraxjnl-2014-206260.40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Crosby A, Soon E, Jones F, Southwood M, Haghighat L, Toshner M, Raine T, Horan I, Yang P, Davenport A, Dunne DW, Morrell NW. S140 BMPR-II deficiency leads to an increase in egg deposition and cytokine release in the lungs of mice chronically infected with schistosomiasis. Thorax 2013. [DOI: 10.1136/thoraxjnl-2013-204457.147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Dunmore BJ, Howard G, Crosby A, Nichols BJ, Morrell NW. S138 Blood outgrowth endothelial cells isolated from patients with pulmonary arterial hypertension possess less caveolae and reduced cavin-2 expression. Thorax 2013. [DOI: 10.1136/thoraxjnl-2013-204457.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Soon E, Crosby A, Southwood M, Pepke-Zaba J, Upton P, Morrell NW. T4 Mutations in BMPR-II Promote Inflammation Via Altered Superoxide Signalling: Insights into the Mechanisms Underlying Pulmonary Arterial Hypertension. Thorax 2012. [DOI: 10.1136/thoraxjnl-2012-202678.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Upton PD, Davies RJ, Tajsic T, Long L, Crosby A, Morrell NW. S38 TGF-Beta1 Negatively Regulates BMP4 Signalling in Human Pulmonary Artery Smooth Muscle Cells Via A Smad3-Dependent Mechanism. Thorax 2012. [DOI: 10.1136/thoraxjnl-2012-202678.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Howard LS, Crosby A, Vaughan P, Sobolewski A, Southwood M, Foster ML, Chilvers ER, Morrell NW. Distinct responses to hypoxia in subpopulations of distal pulmonary artery cells contribute to pulmonary vascular remodeling in emphysema. Pulm Circ 2012; 2:241-9. [PMID: 22837865 PMCID: PMC3401878 DOI: 10.4103/2045-8932.97616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
We have shown previously that hypoxia inhibits the growth of distal human pulmonary artery smooth muscle cells (PASMC) isolated under standard normoxic conditions (PASMC(norm)). By contrast, a subpopulation of PASMC, isolated through survival selection under hypoxia was found to proliferate in response to hypoxia (PASMC(hyp)). We sought to investigate the role of hypoxia-inducible factor (HIF) in these differential responses and to assess the relationship between HIF, proliferation, apoptosis, and pulmonary vascular remodeling in emphysema. PASMC were derived from lobar resections for lung cancer. Hypoxia induced apoptosis in PASMC(norm) (as assessed by TUNEL) and mRNA expression of Bax and Bcl-2, and induced proliferation in PASMC(hyp) (as assessed by (3)H-thymidine incorporation). Both observations were mimicked by dimethyloxallyl glycine, a prolyl-hydroxylase inhibitor used to stabilize HIF under normoxia. Pulmonary vascular remodeling was graded in lung samples taken from patients undergoing lung volume reduction surgery for severe heterogenous emphysema. Carbonic anhydrase IX expression in the medial compartment was used as a surrogate of medial hypoxia and HIF stabilization and increased with increasing vascular remodeling. In addition, a mixture of proliferation, assessed by proliferating-cell nuclear antigen, and apoptosis, assessed by active caspase 3 staining, were both higher in more severely remodeled vessels. Hypoxia drives apoptosis and proliferation via HIF in distinct subpopulations of distal PASMC. These differential responses may be important in the pulmonary vascular remodeling seen in emphysema and further support the key role of HIF in hypoxic pulmonary hypertension.
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Affiliation(s)
- L S Howard
- National Pulmonary Hypertension Service (London), Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
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Soon E, Crosby A, Southwood M, Pepke-Zaba J, Upton P, Morrell NW. S101 Heterozygous loss of BMPR-II predisposes to inflammatory cytokine secretion and pulmonary vascular smooth muscle proliferation. Thorax 2011. [DOI: 10.1136/thoraxjnl-2011-201054b.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Crosby A, Soon E, Jones F, Southwood M, Dunmore B, Dunne D, Morrell NW. S98 BMPR-II mutations do not predispose to pulmonary arterial hypertension in a mouse model of schistosomiasis. Thorax 2011. [DOI: 10.1136/thoraxjnl-2011-201054b.98] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Dunmore BJ, Long L, Yang XD, Crosby A, Morrell NW. S99 The anti-malarial drug and lysosomal inhibitor, chloroquine, increases cell surface expression of BMPR-II. Thorax 2011. [DOI: 10.1136/thoraxjnl-2011-201054b.99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Crosby A, Jones FM, Kolosionek E, Southwood M, Purvis I, Soon E, Butrous G, Dunne DE, Morrell NW. Praziquantel reverses pulmonary hypertension and vascular remodeling in murine schistosomiasis. Am J Respir Crit Care Med 2011; 184:467-73. [PMID: 21659614 DOI: 10.1164/rccm.201101-0146oc] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Schistosomiasis is the most common worldwide cause of pulmonary arterial hypertension. The anti-schistosome drug praziquantel has been shown to reverse the liver fibrosis associated with Schistosoma mansoni in mice. OBJECTIVES We sought to determine whether praziquantel reverses established pulmonary vascular remodeling and pulmonary hypertension in a mouse model of S. mansoni. METHODS Mice were infected percutaneously with S. mansoni. At 17 weeks after infection mice were either killed or received two doses of praziquantel or vehicle by oral gavage. Treated mice were studied at 25 weeks after infection. MEASUREMENTS AND MAIN RESULTS Vehicle-treated mice demonstrated significant increases in right ventricular systolic pressures (RVSP) and right ventricular hypertrophy (RVH) at 25 weeks, accompanied by pulmonary vascular remodeling. The degree of vascular remodeling correlated with proximity to granulomas. The elevation of RVSP and RVH at 25 weeks was dependent on the presence of eggs in the lung. Praziquantel eliminated the production of eggs in feces and led to clearance of eggs from the lung and to a lesser extent from liver. Praziquantel prevented the rise in RVSP and RVH seen in vehicle-treated mice and reversed established pulmonary vascular remodeling. Praziquantel significantly reduced lung mRNA expression of IL-13, IL-8, and IL-4, but did not reduce serum cytokine levels. CONCLUSIONS The development of pulmonary hypertension associated with S. mansoni infection can be prevented by praziquantel, and established vascular remodeling can be reversed. The mechanism involves clearance of lung eggs and reduced local expression of lung cytokines.
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Affiliation(s)
- Alexi Crosby
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Hills Road, Cambridge, United Kingdom
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Abstract
In this article we focus on the pathogenesis and clinical characteristics of schistosomiasis infection on the lung vasculature. Overall, the basic biology and understanding of Schistosoma immune responses and their effect on the cardiopulmonary system is limited in both animal and human models, which hinders clinical care and drug development. The inflammatory response to the eggs in the lung appears to contribute to the remodeling of the pulmonary vessels. Portal hypertension caused by parasitemia also appears to contribute to the development of pathophysiologic alterations of the pulmonary vascular bed. Antischistosomal therapy, praziquantel, used for pulmonary hypertension secondary to schistosomiasis usually has no effect, but it is given to prevent further progression of disease. Currently, there are no clinical trials for the treatment of pulmonary vascular disease secondary to schistosomiasis. Specialty drugs such as phosphodiesterase type 5 or tyrosine kinase inhibitors exhibit some interesting activity, yet are prohibitively expensive, lack safety and efficacy studies in schistosomiasis endemic populations, and tend to be limited by safety, efficacy, route of administration and compliance problems.
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Crosby A, Jones FM, Kakolos E, Southwood M, Purvis I, Butrous G, Dunne DW, Morrell N. S101 Praziquantel prevents progression and reverses pulmonary hypertension and pulmonary vascular remodelling in a mouse model of Schistosomiasis. Thorax 2010. [DOI: 10.1136/thx.2010.150946.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Crosby A, Jones FM, Southwood M, Stewart S, Schermuly R, Butrous G, Dunne DW, Morrell NW. Pulmonary vascular remodeling correlates with lung eggs and cytokines in murine schistosomiasis. Am J Respir Crit Care Med 2009; 181:279-88. [PMID: 19965814 DOI: 10.1164/rccm.200903-0355oc] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Schistosomiasis is considered to be the most common worldwide cause of pulmonary hypertension. At present there is no well-characterized animal model to study the pathobiology of this important condition. OBJECTIVES To develop a mouse model of schistosomiasis, characterize the extent of pulmonary vascular remodeling, and determine the potential role of inflammatory cytokines. METHODS Mice (C57/Bl6) were infected transcutaneously with a high dose (approximately 75-100 cercariae) or a low dose (approximately 30 cercariae) of Schistosoma mansoni, and the development of lung and liver pathology was studied in the subacute (high-dose) and chronic (low-dose) settings. MEASUREMENTS AND MAIN RESULTS In the subacute setting, mice showed few eggs in the lungs and no evidence of pulmonary vascular remodeling. In contrast, chronically infected animals had a much greater lung egg burden and developed marked pulmonary vascular remodeling accompanied by perivascular inflammation from 12 weeks onwards. In addition, we observed the presence of plexiform-like lesions in these mice. Lung egg burden correlated with both liver egg burden and right ventricular (RV) index in the chronic group, although significant RV hypertrophy was lacking. Plasma Th1 and Th2 cytokines increased with time in the chronic group and correlated with the degree of pulmonary vascular remodeling. CONCLUSIONS This study provides evidence for extensive pulmonary vascular remodeling, despite the absence of RV hypertrophy, in a mouse model of schistosomiasis, including the formation of plexiform-like lesions. Inflammatory cytokines and lung egg burden may contribute to vascular lesion formation.
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Affiliation(s)
- Alexi Crosby
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom
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Long L, Crosby A, Yang X, Southwood M, Upton PD, Kim DK, Morrell NW. Altered bone morphogenetic protein and transforming growth factor-beta signaling in rat models of pulmonary hypertension: potential for activin receptor-like kinase-5 inhibition in prevention and progression of disease. Circulation 2009; 119:566-76. [PMID: 19153267 DOI: 10.1161/circulationaha.108.821504] [Citation(s) in RCA: 198] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Recent genetic studies have highlighted the role of the bone morphogenetic protein (BMP)/transforming growth factor (TGF)-beta signaling pathways in the pathogenesis of familial pulmonary arterial hypertension (PAH). It remains unclear whether alterations in these pathways contribute to other forms of pulmonary hypertension and to what extent these changes can be exploited for therapeutic intervention. METHODS AND RESULTS We studied BMP/TGF-beta signaling in 2 rat models of PAH due to chronic hypoxia and monocrotaline. In both models, there was a significant reduction in lung BMP type IA receptor and BMP type II receptor mRNA expression, although these changes were more pronounced in the monocrotaline model. This was accompanied by a reduction in lung levels of phospho-Smad1/5 and Id (inhibitor of DNA binding) gene expression in the monocrotaline model. In contrast, we observed increased TGF-beta activity, again more marked in the monocrotaline model, as evidenced by increased phospho-Smad2/3 and increased expression of TGF-beta-regulated genes. Immunohistochemistry revealed increased TGF-beta(1) expression in pulmonary artery smooth muscle cells and macrophages surrounding remodeled pulmonary arteries in monocrotaline rats. Inhibition of activin receptor-like kinase-5 signaling in vivo with the selective small-molecule inhibitor IN-1233 prevented PAH, right ventricular hypertrophy, and vascular remodeling after monocrotaline injection and inhibited the progression of established PAH in this model. No significant effect was observed in hypoxic PAH. In vitro studies confirmed that TGF-beta stimulated migration of distal rat pulmonary artery smooth muscle cells and that this effect was inhibited by IN-1233. CONCLUSIONS Disruption of BMP/TGF-beta signaling is more pronounced in the monocrotaline model of PAH than in the chronic hypoxia model. Increased TGF-beta activity is associated with greater macrophage recruitment with monocrotaline treatment. Inhibition of TGF-beta signaling via activin receptor-like kinase-5 prevents development and progression of PAH in the monocrotaline model and may involve inhibition of pulmonary artery smooth muscle cell migration.
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Affiliation(s)
- Lu Long
- Division of Respiratory Medicine, Department of Medicine, Box 157, Addenbrooke's Hospital, Hills Rd, Cambridge CB2 2QQ, United Kingdom
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Thomas M, Docx C, Holmes AM, Beach S, Duggan N, England K, Leblanc C, Lebret C, Schindler F, Raza F, Walker C, Crosby A, Davies RJ, Morrell NW, Budd DC. Activin-like kinase 5 (ALK5) mediates abnormal proliferation of vascular smooth muscle cells from patients with familial pulmonary arterial hypertension and is involved in the progression of experimental pulmonary arterial hypertension induced by monocrotaline. Am J Pathol 2008; 174:380-9. [PMID: 19116361 DOI: 10.2353/ajpath.2009.080565] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mutations in the gene for the transforming growth factor (TGF)-beta superfamily receptor, bone morphogenetic protein receptor II, underlie heritable forms of pulmonary arterial hypertension (PAH). Aberrant signaling via TGF-beta receptor I/activin receptor-like kinase 5 may be important for both the development and progression of PAH. We investigated the therapeutic potential of a well-characterized and potent activin receptor-like kinase 5 inhibitor, SB525334 [6-(2-tert-butyl-5-{6-methyl-pyridin-2-yl}-1H-imidazol-4-yl)-quinoxaline] for the treatment of PAH. In this study, we demonstrate that pulmonary artery smooth muscle cells from patients with familial forms of idiopathic PAH exhibit heightened sensitivity to TGF-beta1 in vitro, which can be attenuated after the administration of SB525334. We further demonstrate that SB525334 significantly reverses pulmonary arterial pressure and inhibits right ventricular hypertrophy in a rat model of PAH. Immunohistochemical studies confirmed a significant reduction in pulmonary arteriole muscularization induced by monocrotaline (used experimentally to induce PAH) after treatment of rats with SB525334. Collectively, these data are consistent with a role for the activin receptor-like kinase 5 in the progression of idiopathic PAH and imply that strategies to inhibit activin receptor-like kinase 5 signaling may have therapeutic benefit.
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Affiliation(s)
- Matthew Thomas
- Respiratory Disease Area, Novartis Horsham Research Centre, Horsham, West Sussex, UK
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Abstract
Motivated by experimental results, we present numerical and analytical calculations of the capillary force exerted by a capillary bridge spanning the gap between two parallel flat plates of asymmetric wettability. Depending on whether the sum of the two contact angles is smaller or larger than 180 degrees, the capillary force is either attractive or repulsive at small separations D between the plates. In either cases the magnitude of the force diverges as D approaches zero. The leading order of this divergence is captured by an analytical expression deduced from the geometry of the meniscus of a flat capillary bridge. The results for substrates with different wettability reveal an interesting behavior: with the sum of the contact angles fixed, the magnitude of the capillary force and the rupture separation decreases as the asymmetry in contact angles is increased. In addition, we present the rupture separation, i.e., the maximal extension of a capillary bridge, as a function of the contact angles. Our results provide an extensive picture of surface wettability effects on capillary adhesion.
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Affiliation(s)
- E J De Souza
- Max Planck Institute for Metals Research, Heisenbergstrasse 3, Stuttgart, Germany.
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Talbot NP, Crosby A, Balanos GM, Dorrington KL, Robbins PA. Iron chelation does not potentiate early acclimatisation to sustained hypoxia in humans. FASEB J 2007. [DOI: 10.1096/fasebj.21.6.a925-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Nick P Talbot
- Department of PhysiologyAnatomy and GeneticsUniversity of OxfordSherrington Building, Parks RoadOxfordOX1 3PTUnited Kingdom
| | - Alexi Crosby
- Department of PhysiologyAnatomy and GeneticsUniversity of OxfordSherrington Building, Parks RoadOxfordOX1 3PTUnited Kingdom
| | - George M Balanos
- Department of PhysiologyAnatomy and GeneticsUniversity of OxfordSherrington Building, Parks RoadOxfordOX1 3PTUnited Kingdom
| | - Keith L Dorrington
- Department of PhysiologyAnatomy and GeneticsUniversity of OxfordSherrington Building, Parks RoadOxfordOX1 3PTUnited Kingdom
| | - Peter A Robbins
- Department of PhysiologyAnatomy and GeneticsUniversity of OxfordSherrington Building, Parks RoadOxfordOX1 3PTUnited Kingdom
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Liu C, Smith TG, Balanos GM, Brooks J, Crosby A, Herigstad M, Dorrington KL, Robbins PA. Lack of involvement of the autonomic nervous system in early ventilatory and pulmonary vascular acclimatization to hypoxia in humans. J Physiol 2006; 579:215-25. [PMID: 17138611 PMCID: PMC1865001 DOI: 10.1113/jphysiol.2006.118190] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The activity within the autonomic nervous system may be altered following sustained exposure to hypoxia, and it is possible that this increase in activity underlies the early acclimatization of both ventilation and the pulmonary vasculature to hypoxia. To test this hypothesis, seven individuals were infused with the ganglionic blocker trimetaphan before and after an 8 h exposure to hypoxia. The short half-life of trimetaphan should ensure that the initial infusion does not affect acclimatization to the 8 h hypoxia exposure, and the use of a ganglion blocking agent should inhibit activity within all branches of the autonomic nervous system. During the infusions of trimetaphan, measurements of ventilation and echocardiographic assessments of pulmonary vascular tone (DeltaPmax) were made during euoxia and during a short period of isocapnic hypoxia. Subjects were also studied on two control days, when a saline infusion was substituted for trimetaphan. Trimetaphan had no effect on either euoxic ventilation or the sensitivity of ventilation to acute hypoxia. Trimetaphan significantly reduced DeltaPmax in euoxia (P<0.05), but had no significant effect on the sensitivity of DeltaPmax to acute hypoxia once changes in cardiac output had been controlled for. The 8 h period of hypoxia elevated euoxic ventilation (P<0.001) and DeltaPmax (P<0.001) and increased their sensitivities to acute hypoxia (P<0.001 for both), indicating that significant acclimatization had occurred. Trimetaphan had no effect on the acclimatization response of any of these variables. We conclude that altered autonomic activity following 8 h of hypoxia does not underlie the acclimatization observed in ventilation or pulmonary vascular tone.
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Affiliation(s)
- Chun Liu
- Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford OX1 3PT, UK
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Abstract
Carbon monoxide poisoning is the commonest cause of death by poisoning in the UK and chronic exposure is thought to be a frequently missed diagnosis. Early recognition of carbon monoxide poisoning is vital to institute prompt treatment and to prevent exposure to others. An incident of mass exposure to carbon monoxide is presented where euphoria, lasting several hours, was the only symptom reported in approximately one quarter of the casualties. This has not been reported previously and we believe that mild carbon monoxide intoxication should be included in the list of differential diagnoses of inappropriate euphoria.
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Affiliation(s)
- S F J Clarke
- Division of Chemical Hazards and Poisons, Health Protection Agency, London, SE14 5ER, UK.
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Donoghue S, Fatemian M, Balanos GM, Crosby A, Liu C, O'Connor D, Talbot NP, Robbins PA. Ventilatory acclimatization in response to very small changes in PO2 in humans. J Appl Physiol (1985) 2004; 98:1587-91. [PMID: 15591290 DOI: 10.1152/japplphysiol.01019.2004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ventilatory acclimatization to hypoxia (VAH) consists of a progressive increase in ventilation and decrease in end-tidal Pco(2) (Pet(CO(2))). Underlying VAH, there are also increases in the acute ventilatory sensitivities to hypoxia and hypercapnia. To investigate whether these changes could be induced with very mild alterations in end-tidal Po(2) (Pet(O(2))), two 5-day exposures were compared: 1) mild hypoxia, with Pet(O(2)) held at 10 Torr below the subject's normal value; and 2) mild hyperoxia, with Pet(O(2)) held at 10 Torr above the subject's normal value. During both exposures, Pet(CO(2)) was uncontrolled. For each exposure, the entire protocol required measurements on 13 consecutive mornings: 3 mornings before the hypoxic or hyperoxic exposure, 5 mornings during the exposure, and 5 mornings postexposure. After the subjects breathed room air for at least 30 min, measurements were made of Pet(CO(2)), Pet(O(2)), and the acute ventilatory sensitivities to hypoxia and hypercapnia. Ten subjects completed both protocols. There was a significant increase in the acute ventilatory sensitivity to hypoxia (Gp) after exposure to mild hypoxia, and a significant decrease in Gp after exposure to mild hyperoxia (P < 0.05, repeated-measures ANOVA). No other variables were affected by mild hypoxia or hyperoxia. The results, when combined with those from other studies, suggest that Gp varies linearly with Pet(O(2)), with a sensitivity of 3.5%/Torr (SE 1.0). This sensitivity is sufficient to suggest that Gp is continuously varying in response to normal physiological fluctuations in Pet(O(2)). We conclude that at least some of the mechanisms underlying VAH may have a physiological role at sea level.
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Affiliation(s)
- Simon Donoghue
- University Laboratory of Physiology, Parks Rd., Oxford OX1 3PT, UK
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Crosby A, Talbot NP, Balanos GM, Donoghue S, Fatemian M, Robbins PA. Respiratory effects in humans of a 5-day elevation of end-tidal PCO2 by 8 Torr. J Appl Physiol (1985) 2003; 95:1947-54. [PMID: 14555667 DOI: 10.1152/japplphysiol.00548.2003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aims of this study were to determine 1) whether ventilatory adaptation occurred over a 5-day exposure to a constant elevation in end-tidal Pco2 and 2) whether such an exposure altered the sensitivity of the chemoreflexes to acute hypoxia and hypercapnia. Ten healthy human subjects were studied over a period of 13 days. Their ventilation, chemoreflex sensitivities, and acid-base status were measured daily before, during, and after 5 days of elevated end-tidal Pco2 at 8 Torr above normal. There was no major adaptation of ventilation during the 5 days of hypercapnic exposure. There was an increase in ventilatory chemosensitivity to acute hypoxia (from 1.35 ± 0.08 to 1.70 ± 0.07 l/min/%; P < 0.01) but no change in ventilatory chemosensitivity to acute hypercapnia. There was a degree of compensatory metabolic alkalosis. The results do not support the hypothesis that the ventilatory adaptation to chronic hypercapnia would be much greater with constant elevation of alveolar Pco2 than with constant elevation of inspired Pco2, as has been used in previous studies and in which the feedback loop between ventilation and alveolar Pco2 is left intact.
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Affiliation(s)
- Alexi Crosby
- University Laboratory of Physiology, University of Oxford, Oxford OX1 3PT, United Kingdom
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Abstract
The aims of this study were: (1) to determine the within-subject, between-day variability in end-tidal P(CO2) (P(ET,CO2)); (2) to determine whether the within-subject, between-day variability in P(ET,CO2) was caused by variations in metabolic acid-base status; and (3) to determine whether between-subject variations in blood gas variables arose predominantly through variations in respiratory or renal pH control mechanisms. Fourteen healthy males were studied, of whom 12 provided adequate data for further analysis. Each subject was studied on at least six different occasions, with each visit separated by at least 1 week. On each occasion, P(ET,CO2) was determined over a 4-10 min period using a fine nasal catheter taped just inside the nose, and an arterialised capillary blood sample was obtained from each ear and analysed for blood gases. The following results were obtained. (1) P(ET,CO2) showed a standard deviation (S.D.) for the within-subject, between-day variation of 1.06 mmHg. (2) Less than 5% (P = NS) of the variability in P(ET,CO2) could be explained by underlying variations in metabolic acid-base status. (3) The variation in blood gas values between individuals did not fit a pattern associated with either a predominantly respiratory or a predominantly renal origin. Furthermore, the pattern of variation in the blood gas data suggested that variations in the renal controller for pH and the respiratory controller for pH were not independent. The precise origins of variability in blood gas regulation remain obscure.
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Affiliation(s)
- Alexi Crosby
- University Laboratory of Physiology, University of Oxford, Parks Road, Oxford OX1 3PT, UK
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Abstract
The risk of venous thrombosis may be increased during aeroplane flights, which may, partly, relate to activation of coagulation by hypoxia that is caused by the reduction of pressure in the aircraft cabin. To find out whether hypoxia activates coagulation, we exposed eight healthy human participants to 8 h of isocapnic hypoxia and 8 h of air as a control. Venous blood was sampled before and after the exposure and analysed for markers of activated coagulation. There were no significant changes. We conclude that hypoxia has no major effect on coagulation in the general population.
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Affiliation(s)
- Alexi Crosby
- University Laboratory of Physiology, University of Oxford, Oxford, UK
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Affiliation(s)
- P W O'Carroll
- Public Health Practice Program Office, US Centers for Disease Control and Prevention, USA
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McKoy G, Protonotarios N, Crosby A, Tsatsopoulou A, Anastasakis A, Coonar A, Norman M, Baboonian C, Jeffery S, McKenna WJ. Identification of a deletion in plakoglobin in arrhythmogenic right ventricular cardiomyopathy with palmoplantar keratoderma and woolly hair (Naxos disease). Lancet 2000; 355:2119-24. [PMID: 10902626 DOI: 10.1016/s0140-6736(00)02379-5] [Citation(s) in RCA: 703] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an autosomal dominant heart muscle disorder that causes arrhythmia, heart failure, and sudden death. Previously we mapped the genetic locus for the triad of autosomal recessive ARVC, palmoplantar keratoderma, and woolly hair (Naxos disease) to chromosome 17q21, in which the gene for plakoglobin is encoded. This protein is a key component of desmosomes and adherens junctions, and is important for the tight adhesion of many cell types, including those in the heart and skin. METHODS We studied 19 individuals with Naxos disease, as well as unaffected family members and unrelated individuals from the neighbouring Greek islands of Naxos and Milos. Gene sequence was determined by reverse transcriptase PCR from RNA isolated from the skin of an affected individual and mutations in other cases were confirmed by restriction-enzyme analysis. FINDINGS A homozygous 2 base pair deletion in the plakoglobin gene was identified only in the 19 affected individuals. This deletion caused a frameshift and premature termination of the protein, which was shown by western blot analysis. 29 clinically unaffected family members were heterozygous for the mutation; 20 unrelated individuals from Naxos and 43 autosomal dominant ARVC probands were homozygous for the normal allele. INTERPRETATION The finding of a deletion in plakoglobin in ARVC suggests that the proteins involved in cell-cell adhesion play an important part in maintaining myocyte integrity, and when junctions are disrupted, cell death, and fibrofatty replacement occur. Therefore, the discovery of a mutation in a protein with functions in maintaining cell junction integrity has important implications for other dominant forms of ARVC, related cardiomyopathies, and other cutaneous diseases.
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Affiliation(s)
- G McKoy
- Department of Cardiological Sciences, St George's Hospital Medical School, London, UK
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Afzal AR, Rajab A, Fenske C, Crosby A, Lahiri N, Ternes-Pereira E, Murday VA, Houlston R, Patton MA, Jeffery S. Linkage of recessive Robinow syndrome to a 4 cM interval on chromosome 9q22. Hum Genet 2000; 106:351-4. [PMID: 10798366 DOI: 10.1007/s004390051049] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Autosomal recessive Robinow syndrome is a form of mesomelic dwarfism with multiple rib and vertebral anomalies. Using autozygosity mapping we have identified a genetic locus (RBNW1) for this syndrome at chromosome 9q22 in seven consanguineous families from Oman. Our results indicate that the gene lies within a 4 cM region between markers D9S1836 and D9S1803 (maximum multipoint LOD score 12.3). In addition, we have analysed two non-Omani families with autosomal recessive Robinow and found no genetic heterogeneity.
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Affiliation(s)
- A R Afzal
- Medical Genetics Unit, St. George's Hospital Medical School, London, UK
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Jeffery S, Crosby A, Plange-Rhule J, Amoah-Danquah J, Acheampong JW, Eastwood JB, Malik AK. Evidence from a Ghanaian population of known African descent to support the proposition that hemochromatosis is a Caucasian disorder. Genet Test 2000; 3:375-7. [PMID: 10627947 DOI: 10.1089/gte.1999.3.375] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Mutations in the HFE gene on chromosome 6 are believed to cause the iron overload disorder hemochromatosis, the most common single gene disorder in northern Europeans. Two mutations have been described previously: C282Y, with an allele frequency of between 3% and 10% in the caucasian population, and H63D, which has an allele frequency of 16%. Published data shows that C282Y appears to be causative in the homozygous state, while the frequency of H63D/C282Y compound heterozygotes is much greater than expected in patient groups. There also appears to be a slightly elevated risk for H63D homozygotes. Hemochromatosis has been thought to be primarily a caucasian disorder. We have studied 97 healthy, black Ghanaian subjects, whose parents and grandparents were also African, to find the frequency of the two mutations. C282Y was absent, while H63D occurred in 2 individuals. These differences are significant at the 0.05 and 0.001 levels, respectively. The prevalence of H63D homozygotes in this population at 1 in 10,000 is clearly of no use in studying the effect of this genotype on phenotype. However, this study suggests an absence of the C282Y mutation in African populations, and the possibility that other populations might provide different genotypes and hence an analysis of H63D risk. A possible heterozygote advantage for the mutation is discussed.
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Affiliation(s)
- S Jeffery
- Medical Genetics Unit, St George's Medical School, London, UK.
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Jeffery S, Saggar Malik AK, Crosby A, Bland M, Eastwood JB, Amoah-Danquah J, Acheampong JW, Plange-Rhule J. A dominant relationship between the ACE D allele and serum ACE levels in a Ghanaian population. J Med Genet 1999; 36:869-70. [PMID: 10636736 PMCID: PMC1734264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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Crosby A, Jeffery S, Homfray T, Taylor R, Patton M. Prenatal diagnosis and the subsequent mutation analysis in a family with carbohydrate-deficient glycoprotein type I syndrome: growing evidence to support founder effects within CDG1 populations. Genet Test 1999; 3:305-7. [PMID: 10495932 DOI: 10.1089/109065799316644] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Carbohydrate deficient-glycoprotein syndrome type I (CDG1 or Jaeken Syndrome) is an autosomal recessive multisystem disease with severe early involvement of the nervous system. Mutations in the phosphomannomutase 2 (PMM2) gene have recently been identified in 16 affected individuals. In the current study, we have described a CDG1 family where gene tracking had been used to perform prenatal diagnosis before the isolation of the CDG1 gene. Haplotype analysis indicated that the unborn child had inherited the maternal 'normal' allele, but a critical recombination event meant that it was impossible to determine if the child had inherited the paternal mutation. Single-strand conformation polymorphism and sequence analysis revealed that the mother was a carrier of a C-->A transversion at position 357 (F119L), and that the father was a carrier of a G-->A transition at position 425 (R141H). The unborn child had inherited the paternal R141H mutation. Because only three mutations have previously been reported in UK families, of which F119L and R141H are two, and given that there is evidence of allelic association in CDG1 families, it is possible that a limited number of ancestral mutations have given rise to most cases of CDG1 in any one population.
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Affiliation(s)
- A Crosby
- Medical Genetics Unit, St. George's Medical School, London, England
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