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Deng R, Medico-Salsench E, Nikoncuk A, Ramakrishnan R, Lanko K, Kühn NA, van der Linde HC, Lor-Zade S, Albuainain F, Shi Y, Yousefi S, Capo I, van den Herik EM, van Slegtenhorst M, van Minkelen R, Geeven G, Mulder MT, Ruijter GJG, Lütjohann D, Jacobs EH, Houlden H, Pagnamenta AT, Metcalfe K, Jackson A, Banka S, De Simone L, Schwaede A, Kuntz N, Palculict TB, Abbas S, Umair M, AlMuhaizea M, Colak D, AlQudairy H, Alsagob M, Pereira C, Trunzo R, Karageorgou V, Bertoli-Avella AM, Bauer P, Bouman A, Hoefsloot LH, van Ham TJ, Issa M, Zaki MS, Gleeson JG, Willemsen R, Kaya N, Arold ST, Maroofian R, Sanderson LE, Barakat TS. AMFR dysfunction causes autosomal recessive spastic paraplegia in human that is amenable to statin treatment in a preclinical model. Acta Neuropathol 2023; 146:353-368. [PMID: 37119330 PMCID: PMC10328903 DOI: 10.1007/s00401-023-02579-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/01/2023]
Abstract
Hereditary spastic paraplegias (HSP) are rare, inherited neurodegenerative or neurodevelopmental disorders that mainly present with lower limb spasticity and muscle weakness due to motor neuron dysfunction. Whole genome sequencing identified bi-allelic truncating variants in AMFR, encoding a RING-H2 finger E3 ubiquitin ligase anchored at the membrane of the endoplasmic reticulum (ER), in two previously genetically unexplained HSP-affected siblings. Subsequently, international collaboration recognized additional HSP-affected individuals with similar bi-allelic truncating AMFR variants, resulting in a cohort of 20 individuals from 8 unrelated, consanguineous families. Variants segregated with a phenotype of mainly pure but also complex HSP consisting of global developmental delay, mild intellectual disability, motor dysfunction, and progressive spasticity. Patient-derived fibroblasts, neural stem cells (NSCs), and in vivo zebrafish modeling were used to investigate pathomechanisms, including initial preclinical therapy assessment. The absence of AMFR disturbs lipid homeostasis, causing lipid droplet accumulation in NSCs and patient-derived fibroblasts which is rescued upon AMFR re-expression. Electron microscopy indicates ER morphology alterations in the absence of AMFR. Similar findings are seen in amfra-/- zebrafish larvae, in addition to altered touch-evoked escape response and defects in motor neuron branching, phenocopying the HSP observed in patients. Interestingly, administration of FDA-approved statins improves touch-evoked escape response and motor neuron branching defects in amfra-/- zebrafish larvae, suggesting potential therapeutic implications. Our genetic and functional studies identify bi-allelic truncating variants in AMFR as a cause of a novel autosomal recessive HSP by altering lipid metabolism, which may potentially be therapeutically modulated using precision medicine with statins.
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Affiliation(s)
- Ruizhi Deng
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Whole Genome Sequencing Implementation and Research Task Force, Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Eva Medico-Salsench
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Anita Nikoncuk
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Reshmi Ramakrishnan
- Bioscience Program, Biological and Environmental Science and Engineering Division, Computational Bioscience Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia
| | - Kristina Lanko
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Nikolas A. Kühn
- Department of Cell Biology, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Herma C. van der Linde
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Sarah Lor-Zade
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Fatimah Albuainain
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Yuwei Shi
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Soheil Yousefi
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Whole Genome Sequencing Implementation and Research Task Force, Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Ivan Capo
- Department for Histology and Embryology, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | | | - Marjon van Slegtenhorst
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Rick van Minkelen
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Geert Geeven
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Whole Genome Sequencing Implementation and Research Task Force, Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Monique T. Mulder
- Department of Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - George J. G. Ruijter
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Edwin H. Jacobs
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, UK
| | - Alistair T. Pagnamenta
- NIHR Biomedical Research Centre, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Kay Metcalfe
- Manchester Centre for Genomic Medicine, St Mary’s Hospital, Health Innovation Manchester, Manchester University Foundation NHS Trust, Manchester, UK
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PL UK
| | - Adam Jackson
- Manchester Centre for Genomic Medicine, St Mary’s Hospital, Health Innovation Manchester, Manchester University Foundation NHS Trust, Manchester, UK
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PL UK
| | - Siddharth Banka
- Manchester Centre for Genomic Medicine, St Mary’s Hospital, Health Innovation Manchester, Manchester University Foundation NHS Trust, Manchester, UK
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PL UK
| | - Lenika De Simone
- Division of Neurology, Division of Genetics, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, USA
| | - Abigail Schwaede
- Division of Neurology, Division of Genetics, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, USA
| | - Nancy Kuntz
- Division of Neurology, Division of Genetics, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, USA
| | | | - Safdar Abbas
- Department of Biological Science, Dartmouth College, Hanover, NH USA
| | - Muhammad Umair
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
- Department of Life Sciences, School of Science, University of Management and Technology (UMT), Lahore, Pakistan
| | - Mohammed AlMuhaizea
- Neuroscience Centre, King Faisal Specialist Hospital and Research Centre (KFSHRC), MBC: 76, Riyadh, 11211 Saudi Arabia
| | - Dilek Colak
- Molecular Oncology Department, King Faisal Specialist Hospital and Research Centre (KFSHRC), MBC: 03, Riyadh, 11211 Saudi Arabia
| | - Hanan AlQudairy
- Translational Genomics Department, Center for Genomics Medicine, King Faisal Specialist Hospital and Research Centre, MBC: 26, PO Box: 3354, Riyadh, 11211 Saudi Arabia
| | - Maysoon Alsagob
- Translational Genomics Department, Center for Genomics Medicine, King Faisal Specialist Hospital and Research Centre, MBC: 26, PO Box: 3354, Riyadh, 11211 Saudi Arabia
- Applied Genomics Technologies Institute, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
| | | | | | | | | | | | - Arjan Bouman
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Lies H. Hoefsloot
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Whole Genome Sequencing Implementation and Research Task Force, Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Tjakko J. van Ham
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Whole Genome Sequencing Implementation and Research Task Force, Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Mahmoud Issa
- Clinical Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Maha S. Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Joseph G. Gleeson
- Departments of Neurosciences and Pediatrics, Howard Hughes Medical Institute, University of California, Rady Children’s Institute for Genomic Medicine, San Diego, USA
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Namik Kaya
- Translational Genomics Department, Center for Genomics Medicine, King Faisal Specialist Hospital and Research Centre, MBC: 26, PO Box: 3354, Riyadh, 11211 Saudi Arabia
| | - Stefan T. Arold
- Bioscience Program, Biological and Environmental Science and Engineering Division, Computational Bioscience Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia
- Centre de Biologie Structurale, CNRS, INSERM, Université de Montpellier, 34090 Montpellier, France
| | - Reza Maroofian
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, UK
| | - Leslie E. Sanderson
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Tahsin Stefan Barakat
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Whole Genome Sequencing Implementation and Research Task Force, Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Discovery Unit, Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
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Sherlock ME, Baquero Galvis L, Vicens Q, Kieft JS, Jagannathan S. Principles, mechanisms, and biological implications of translation termination-reinitiation. RNA (NEW YORK, N.Y.) 2023; 29:865-884. [PMID: 37024263 PMCID: PMC10275272 DOI: 10.1261/rna.079375.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/28/2023] [Indexed: 06/11/2023]
Abstract
The gene expression pathway from DNA sequence to functional protein is not as straightforward as simple depictions of the central dogma might suggest. Each step is highly regulated, with complex and only partially understood molecular mechanisms at play. Translation is one step where the "one gene-one protein" paradigm breaks down, as often a single mature eukaryotic mRNA leads to more than one protein product. One way this occurs is through translation reinitiation, in which a ribosome starts making protein from one initiation site, translates until it terminates at a stop codon, but then escapes normal recycling steps and subsequently reinitiates at a different downstream site. This process is now recognized as both important and widespread, but we are only beginning to understand the interplay of factors involved in termination, recycling, and initiation that cause reinitiation events. There appear to be several ways to subvert recycling to achieve productive reinitiation, different types of stresses or signals that trigger this process, and the mechanism may depend in part on where the event occurs in the body of an mRNA. This perspective reviews the unique characteristics and mechanisms of reinitiation events, highlights the similarities and differences between three major scenarios of reinitiation, and raises outstanding questions that are promising avenues for future research.
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Affiliation(s)
- Madeline E Sherlock
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Quentin Vicens
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
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Dannewitz Prosseda S, Ali MK, Spiekerkoetter E. Novel Advances in Modifying BMPR2 Signaling in PAH. Genes (Basel) 2020; 12:genes12010008. [PMID: 33374819 PMCID: PMC7824173 DOI: 10.3390/genes12010008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 12/31/2022] Open
Abstract
Pulmonary Arterial Hypertension (PAH) is a disease of the pulmonary arteries, that is characterized by progressive narrowing of the pulmonary arterial lumen and increased pulmonary vascular resistance, ultimately leading to right ventricular dysfunction, heart failure and premature death. Current treatments mainly target pulmonary vasodilation and leave the progressive vascular remodeling unchecked resulting in persistent high morbidity and mortality in PAH even with treatment. Therefore, novel therapeutic strategies are urgently needed. Loss of function mutations of the Bone Morphogenetic Protein Receptor 2 (BMPR2) are the most common genetic factor in hereditary forms of PAH, suggesting that the BMPR2 pathway is fundamentally important in the pathogenesis. Dysfunctional BMPR2 signaling recapitulates the cellular abnormalities in PAH as well as the pathobiology in experimental pulmonary hypertension (PH). Approaches to restore BMPR2 signaling by increasing the expression of BMPR2 or its downstream signaling targets are currently actively explored as novel ways to prevent and improve experimental PH as well as PAH in patients. Here, we summarize existing as well as novel potential treatment strategies for PAH that activate the BMPR2 receptor pharmaceutically or genetically, increase the receptor availability at the cell surface, or reconstitute downstream BMPR2 signaling.
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Affiliation(s)
- Svenja Dannewitz Prosseda
- Division Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA; (S.D.P.); (M.K.A.)
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford, CA 94305, USA
- Institute for Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs University Freiburg, 79104 Freiburg, Germany
| | - Md Khadem Ali
- Division Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA; (S.D.P.); (M.K.A.)
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford, CA 94305, USA
| | - Edda Spiekerkoetter
- Division Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA; (S.D.P.); (M.K.A.)
- Vera Moulton Wall Center for Pulmonary Vascular Diseases, Stanford, CA 94305, USA
- Correspondence:
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4
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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] [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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Dyle MC, Kolakada D, Cortazar MA, Jagannathan S. How to get away with nonsense: Mechanisms and consequences of escape from nonsense-mediated RNA decay. WILEY INTERDISCIPLINARY REVIEWS. RNA 2020; 11:e1560. [PMID: 31359616 PMCID: PMC10685860 DOI: 10.1002/wrna.1560] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/25/2019] [Accepted: 07/04/2019] [Indexed: 11/04/2023]
Abstract
Nonsense-mediated RNA decay (NMD) is an evolutionarily conserved RNA quality control process that serves both as a mechanism to eliminate aberrant transcripts carrying premature stop codons, and to regulate expression of some normal transcripts. For a quality control process, NMD exhibits surprising variability in its efficiency across transcripts, cells, tissues, and individuals in both physiological and pathological contexts. Whether an aberrant RNA is spared or degraded, and by what mechanism, could determine the phenotypic outcome of a disease-causing mutation. Hence, understanding the variability in NMD is not only important for clinical interpretation of genetic variants but also may provide clues to identify novel therapeutic approaches to counter genetic disorders caused by nonsense mutations. Here, we discuss the current knowledge of NMD variability and the mechanisms that allow certain transcripts to escape NMD despite the presence of NMD-inducing features. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA in Disease and Development > RNA in Disease RNA Turnover and Surveillance > Regulation of RNA Stability.
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Affiliation(s)
- Michael C. Dyle
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Divya Kolakada
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Molecular Biology Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Michael A. Cortazar
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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Abbasi Y, Jabbari J, Jabbari R, Glinge C, Izadyar S, Spiekerkoetter E, Zamanian RT, Carlsen J, Tfelt‐Hansen J. Exome data clouds the pathogenicity of genetic variants in Pulmonary Arterial Hypertension. Mol Genet Genomic Med 2018; 6:835-844. [PMID: 30084161 PMCID: PMC6160702 DOI: 10.1002/mgg3.452] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 04/25/2018] [Accepted: 06/03/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND We aimed to provide a set of previously reported PAH-associated missense and nonsense variants, and evaluate the pathogenicity of those variants. METHODS The Human Gene Mutation Database, PubMed, and Google Scholar were searched for previously reported PAH-associated genes and variants. Thereafter, both exome sequencing project and exome aggregation consortium as background population searched for previously reported PAH-associated missense and nonsense variants. The pathogenicity of previously reported PAH-associated missense variants evaluated by using four in silico prediction tools. RESULTS In total, 14 PAH-associated genes and 180 missense and nonsense variants were gathered. The BMPR2, the most frequent reported gene, encompasses 135 of 180 missense and nonsense variants. The exome sequencing project comprised 9, and the exome aggregation consortium counted 25 of 180 PAH-associated missense and nonsense variants. The TOPBP1 and ENG genes are unlikely to be the monogenic cause of PAH pathogenesis based on allele frequency in background population and prediction analysis. CONCLUSION This is the first evaluation of previously reported PAH-associated missense and nonsense variants. The BMPR2 identified as the major gene out of 14 PAH-associated genes. Based on findings, the ENG and TOPBP1 gene are not likely to be the monogenic cause of PAH.
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Affiliation(s)
- Yeganeh Abbasi
- Heart CentreDepartment of CardiologyCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
- Department of CardiologySection for Pulmonary Hypertension and Right Heart FailureCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
| | | | - Reza Jabbari
- Heart CentreDepartment of CardiologyCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
- Department of CardiologySection for Pulmonary Hypertension and Right Heart FailureCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
| | - Charlotte Glinge
- Heart CentreDepartment of CardiologyCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
| | - Seyed Bahador Izadyar
- Heart CentreDepartment of CardiologyCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
| | - Edda Spiekerkoetter
- Division of Pulmonary and Critical CareStanford University School of MedicineCalifornia
| | - Roham T. Zamanian
- Division of Pulmonary and Critical CareStanford University School of MedicineCalifornia
| | - Jørn Carlsen
- Heart CentreDepartment of CardiologyCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
- Department of CardiologySection for Pulmonary Hypertension and Right Heart FailureCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
| | - Jacob Tfelt‐Hansen
- Heart CentreDepartment of CardiologyCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
- Department of CardiologySection for Pulmonary Hypertension and Right Heart FailureCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
- Department of Forensic MedicineFaculty of Medical SciencesUniversity of CopenhagenDenmark
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7
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Frump A, Prewitt A, de Caestecker MP. BMPR2 mutations and endothelial dysfunction in pulmonary arterial hypertension (2017 Grover Conference Series). Pulm Circ 2018; 8:2045894018765840. [PMID: 29521190 PMCID: PMC5912278 DOI: 10.1177/2045894018765840] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/26/2018] [Indexed: 12/22/2022] Open
Abstract
Despite the discovery more than 15 years ago that patients with hereditary pulmonary arterial hypertension (HPAH) inherit BMP type 2 receptor ( BMPR2) mutations, it is still unclear how these mutations cause disease. In part, this is attributable to the rarity of HPAH and difficulty obtaining tissue samples from patients with early disease. However, in addition, limitations to the approaches used to study the effects of BMPR2 mutations on the pulmonary vasculature have restricted our ability to determine how individual mutations give rise to progressive pulmonary vascular pathology in HPAH. The importance of understanding the mechanisms by which BMPR2 mutations cause disease in patients with HPAH is underscored by evidence that there is reduced BMPR2 expression in patients with other, more common, non-hereditary form of PAH, and that restoration of BMPR2 expression reverses established disease in experimental models of pulmonary hypertension. In this paper, we focus on the effects on endothelial function. We discuss some of the controversies and challenges that have faced investigators exploring the role of BMPR2 mutations in HPAH, focusing specifically on the effects different BMPR2 mutation have on endothelial function, and whether there are qualitative differences between different BMPR2 mutations. We discuss evidence that BMPR2 signaling regulates a number of responses that may account for endothelial abnormalities in HPAH and summarize limitations of the models that are used to study these effects. Finally, we discuss evidence that BMPR2-dependent effects on endothelial metabolism provides a unifying explanation for the many of the BMPR2 mutation-dependent effects that have been described in patients with HPAH.
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Affiliation(s)
- Andrea Frump
- Division
of Pulmonary, Critical Care, Sleep and Occupational Medicine, Indiana University
School of Medicine, Indianapolis, IN,
USA
| | | | - Mark P. de Caestecker
- Division
of Nephrology and Hypertension, Department of Medicine, Vanderbilt University
Medical center, Nashville, TN, USA
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8
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Kim MJ, Park SY, Chang HR, Jung EY, Munkhjargal A, Lim JS, Lee MS, Kim Y. Clinical significance linked to functional defects in bone morphogenetic protein type 2 receptor, BMPR2. BMB Rep 2018; 50:308-317. [PMID: 28391780 PMCID: PMC5498141 DOI: 10.5483/bmbrep.2017.50.6.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Indexed: 12/18/2022] Open
Abstract
Bone morphogenetic protein type 2 receptor (BMPR2) is one of the transforming growth factor-β (TGF-β) superfamily receptors, performing diverse roles during embryonic development, vasculogenesis, and osteogenesis. Human BMPR2 consists of 1,038 amino acids, and contains functionally conserved extracellular, transmembrane, kinase, and C-terminal cytoplasmic domains. Bone morphogenetic proteins (BMPs) engage the tetrameric complex, composed of BMPR2 and its corresponding type 1 receptors, which initiates SMAD proteins-mediated signal transduction leading to the expression of target genes implicated in the development or differentiation of the embryo, organs and bones. In particular, genetic alterations of BMPR2 gene are associated with several clinical disorders, including representative pulmonary arterial hypertension, cancers, and metabolic diseases, thus demonstrating the physiological importance of BMPR2. In this mini review, we summarize recent findings regarding the molecular basis of BMPR2 functions in BMP signaling, and the versatile roles of BMPR2. In addition, various aspects of experimentally validated pathogenic mutations of BMPR2 and the linked human diseases will also be discussed, which are important in clinical settings for diagnostics and treatment.
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Affiliation(s)
- Myung-Jin Kim
- Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Korea
| | - Seon Young Park
- Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Korea
| | - Hae Ryung Chang
- Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Korea
| | - Eun Young Jung
- Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Korea
| | - Anudari Munkhjargal
- Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Korea
| | - Jong-Seok Lim
- Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Korea
| | - Myeong-Sok Lee
- Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Korea
| | - Yonghwan Kim
- Department of Biological Sciences, Sookmyung Women's University, Seoul 04310, Korea
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9
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BMP type II receptor as a therapeutic target in pulmonary arterial hypertension. Cell Mol Life Sci 2017; 74:2979-2995. [PMID: 28447104 PMCID: PMC5501910 DOI: 10.1007/s00018-017-2510-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/09/2017] [Accepted: 03/17/2017] [Indexed: 12/30/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a chronic disease characterized by a progressive elevation in mean pulmonary arterial pressure. This occurs due to abnormal remodeling of small peripheral lung vasculature resulting in progressive occlusion of the artery lumen that eventually causes right heart failure and death. The most common cause of PAH is inactivating mutations in the gene encoding a bone morphogenetic protein type II receptor (BMPRII). Current therapeutic options for PAH are limited and focused mainly on reversal of pulmonary vasoconstriction and proliferation of vascular cells. Although these treatments can relieve disease symptoms, PAH remains a progressive lethal disease. Emerging data suggest that restoration of BMPRII signaling in PAH is a promising alternative that could prevent and reverse pulmonary vascular remodeling. Here we will focus on recent advances in rescuing BMPRII expression, function or signaling to prevent and reverse pulmonary vascular remodeling in PAH and its feasibility for clinical translation. Furthermore, we summarize the role of described miRNAs that directly target the BMPR2 gene in blood vessels. We discuss the therapeutic potential and the limitations of promising new approaches to restore BMPRII signaling in PAH patients. Different mutations in BMPR2 and environmental/genetic factors make PAH a heterogeneous disease and it is thus likely that the best approach will be patient-tailored therapies.
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10
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Matos ML, Lapyckyj L, Rosso M, Besso MJ, Mencucci MV, Briggiler CIM, Giustina S, Furlong LI, Vazquez-Levin MH. Identification of a Novel Human E-Cadherin Splice Variant and Assessment of Its Effects Upon EMT-Related Events. J Cell Physiol 2016; 232:1368-1386. [PMID: 27682981 DOI: 10.1002/jcp.25622] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 09/27/2016] [Indexed: 12/15/2022]
Abstract
Epithelial Cadherin (E-cadherin) is involved in calcium-dependent cell-cell adhesion and signal transduction. The E-cadherin decrease/loss is a hallmark of Epithelial to Mesenchymal Transition (EMT), a key event in tumor progression. The underlying molecular mechanisms that trigger E-cadherin loss and consequent EMT have not been completely elucidated. This study reports the identification of a novel human E-cadherin variant mRNA produced by alternative splicing. A bioinformatics evaluation of the novel mRNA sequence and biochemical verifications suggest its regulation by Nonsense-Mediated mRNA Decay (NMD). The novel E-cadherin variant was detected in 29/42 (69%) human tumor cell lines, expressed at variable levels (E-cadherin variant expression relative to the wild type mRNA = 0.05-11.6%). Stable transfection of the novel E-cadherin variant in MCF-7 cells (MCF7Ecadvar) resulted in downregulation of wild type E-cadherin expression (transcript/protein) and EMT-related changes, among them acquisition of a fibroblastic-like cell phenotype, increased expression of Twist, Snail, Zeb1, and Slug transcriptional repressors and decreased expression of ESRP1 and ESRP2 RNA binding proteins. Moreover, loss of cytokeratins and gain of vimentin, N-cadherin and Dysadherin/FXYD5 proteins was observed. Dramatic changes in cell behavior were found in MCF7Ecadvar, as judged by the decreased cell-cell adhesion (Hanging-drop assay), increased cell motility (Wound Healing) and increased cell migration (Transwell) and invasion (Transwell w/Matrigel). Some changes were found in MCF-7 cells incubated with culture medium supplemented with conditioned medium from HEK-293 cells transfected with the E-cadherin variant mRNA. Further characterization of the novel E-cadherin variant will help understanding the molecular basis of tumor progression and improve cancer diagnosis. J. Cell. Physiol. 232: 1368-1386, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- María Laura Matos
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Lara Lapyckyj
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Marina Rosso
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - María José Besso
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - María Victoria Mencucci
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Clara Isabel Marín Briggiler
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Silvina Giustina
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Laura Inés Furlong
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
| | - Mónica Hebe Vazquez-Levin
- Instituto de Biología y Medicina Experimental (IBYME). National Research Council of Argentina (CONICET). Fundación IBYME, Vuelta de Obligado 2490, Buenos Aires, Argentina
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11
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Kane MS, Vilboux T, Wolfe LA, Lee PR, Wang Y, Huddleston KC, Vockley JG, Niederhuber JE, Solomon BD. Aberrant splicing induced by the most common EPG5 mutation in an individual with Vici syndrome. Brain 2016; 139:e52. [PMID: 27343256 DOI: 10.1093/brain/aww135] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Megan S Kane
- 1 Inova Translational Medicine Institute, Inova Health System, 3300 Gallows Road, Falls Church, Virginia 22042, USA
| | - Thierry Vilboux
- 1 Inova Translational Medicine Institute, Inova Health System, 3300 Gallows Road, Falls Church, Virginia 22042, USA
| | - Lynne A Wolfe
- 2 NIH Undiagnosed Diseases Program, Common Fund, Office of the Director and the National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA 3 Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Paul R Lee
- 2 NIH Undiagnosed Diseases Program, Common Fund, Office of the Director and the National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yupeng Wang
- 1 Inova Translational Medicine Institute, Inova Health System, 3300 Gallows Road, Falls Church, Virginia 22042, USA
| | - Kathi C Huddleston
- 1 Inova Translational Medicine Institute, Inova Health System, 3300 Gallows Road, Falls Church, Virginia 22042, USA
| | - Joseph G Vockley
- 1 Inova Translational Medicine Institute, Inova Health System, 3300 Gallows Road, Falls Church, Virginia 22042, USA 4 Department of Pediatrics, Virginia Commonwealth University School of Medicine, 1201 E Marshall St, Richmond, Virginia 23298, USA
| | - John E Niederhuber
- 1 Inova Translational Medicine Institute, Inova Health System, 3300 Gallows Road, Falls Church, Virginia 22042, USA 5 Adjunct Professor Oncology, Johns Hopkins University School of Medicine, 733 North Broadway Street, Baltimore, Maryland 21205, USA
| | - Benjamin D Solomon
- 1 Inova Translational Medicine Institute, Inova Health System, 3300 Gallows Road, Falls Church, Virginia 22042, USA 4 Department of Pediatrics, Virginia Commonwealth University School of Medicine, 1201 E Marshall St, Richmond, Virginia 23298, USA 6 Inova Children's Hospital, Inova Health System, 3300 Gallows Road, Falls Church, Virginia 22042, USA
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12
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Kropski JA, Mitchell DB, Markin C, Polosukhin VV, Choi L, Johnson JE, Lawson WE, Phillips JA, Cogan JD, Blackwell TS, Loyd JE. A novel dyskerin (DKC1) mutation is associated with familial interstitial pneumonia. Chest 2014; 146:e1-e7. [PMID: 24504062 DOI: 10.1378/chest.13-2224] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Short telomeres are frequently identified in patients with idiopathic pulmonary fibrosis (IPF) and its inherited form, familial interstitial pneumonia (FIP). We identified a kindred with FIP with short telomeres who did not carry a mutation in known FIP genes TERT or hTR . We performed targeted sequencing of other telomere-related genes to identify the genetic basis of FIP in this kindred. The proband was a 69 year-old man with dyspnea, restrictive pulmonary function test results, and reticular changes on high-resolution CT scan. An older male sibling had died from IPF. The proband had markedly shortened telomeres in peripheral blood and undetectably short telomeres in alveolar epithelial cells. Polymerase chain reaction-based sequencing of NOP10 , TINF2 , NHP2 , and DKC1 revealed that both affected siblings shared a novel A to G 1213 transition in DKC1 near the hTR binding domain that is predicted to encode a Thr405Ala amino acid substitution. hTR levels were decreased out of proportion to DKC1 expression in the T405A DKC1 proband, suggesting this mutation destabilizes hTR and impairs telomerase function. This DKC1 variant represents the third telomere-related gene identified as a genetic cause of FIP. Further investigation into the mechanism by which dyskerin contributes to the development of lung fibrosis is warranted.
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Affiliation(s)
- Jonathan A Kropski
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN.
| | - Daphne B Mitchell
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Cheryl Markin
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Vasiliy V Polosukhin
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Leena Choi
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN
| | - Joyce E Johnson
- Department of Pediatrics, Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN
| | - William E Lawson
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN; Department of Veterans Affairs Medical Center, Vanderbilt University School of Medicine, Nashville, TN
| | - John A Phillips
- Division of Medical Genetics and Genomic Medicine, Vanderbilt University School of Medicine, Nashville, TN; Department of Pediatrics, Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN
| | - Joy D Cogan
- Division of Medical Genetics and Genomic Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Timothy S Blackwell
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN; Department of Veterans Affairs Medical Center, Vanderbilt University School of Medicine, Nashville, TN; Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN; Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN
| | - James E Loyd
- Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Vanderbilt University School of Medicine, Nashville, TN
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13
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West J, Austin E, Fessel JP, Loyd J, Hamid R. Rescuing the BMPR2 signaling axis in pulmonary arterial hypertension. Drug Discov Today 2014; 19:1241-5. [PMID: 24794464 DOI: 10.1016/j.drudis.2014.04.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 04/24/2014] [Indexed: 01/10/2023]
Abstract
Pulmonary arterial hypertension (PAH) is a lethal disorder characterized by pulmonary arterial remodeling, increased right ventricular systolic pressure (RVSP), vasoconstriction and inflammation. The heritable form of PAH (HPAH) is usually (>80%) caused by mutations in the bone morphogenic protein receptor 2 (BMPR2) gene. Existing treatments for PAH typically focus on the end-stage sequelae of the disease, but do not address underlying mechanisms of vascular obstruction and blood flow and thus, in the long run, have limited effect because they treat the symptoms rather than the cause. Over the past decade, improved understanding of the molecular mechanisms behind the disease has enabled us to consider several novel therapeutic pathways. These include approaches directed toward BMPR2 gene expression, alternative splicing, downstream BMP signaling, metabolic pathways and the role of estrogens and estrogenic compounds in BMP signaling. It is likely that, ultimately, only one or two of these pathways will generate meaningful treatment options, however the potential benefits to PAH patients are still likely to be significant.
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Affiliation(s)
- James West
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - Eric Austin
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Joshua P Fessel
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - James Loyd
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Rizwan Hamid
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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14
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Frump AL, Lowery JW, Hamid R, Austin ED, de Caestecker M. Abnormal trafficking of endogenously expressed BMPR2 mutant allelic products in patients with heritable pulmonary arterial hypertension. PLoS One 2013; 8:e80319. [PMID: 24224048 PMCID: PMC3818254 DOI: 10.1371/journal.pone.0080319] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/07/2013] [Indexed: 12/28/2022] Open
Abstract
More than 200 heterozygous mutations in the type 2 BMP receptor gene, BMPR2, have been identified in patients with Heritable Pulmonary Arterial Hypertension (HPAH). More severe clinical outcomes occur in patients with BMPR2 mutations by-passing nonsense-mediated mRNA decay (NMD negative mutations). These comprise 40% of HPAH mutations and are predicted to express BMPR2 mutant products. However expression of endogenous NMD negative BMPR2 mutant products and their effect on protein trafficking and signaling function have never been described. Here, we characterize the expression and trafficking of an HPAH-associated NMD negative BMPR2 mutation that results in an in-frame deletion of BMPR2 EXON2 (BMPR2ΔEx2) in HPAH patient-derived lymphocytes and in pulmonary endothelial cells (PECs) from mice carrying the same in-frame deletion of Exon 2 (Bmpr2 (ΔEx2/+) mice). The endogenous BMPR2ΔEx2 mutant product does not reach the cell surface and is retained in the endoplasmic reticulum. Moreover, chemical chaperones 4-PBA and TUDCA partially restore cell surface expression of Bmpr2ΔEx2 in PECs, suggesting that the mutant product is mis-folded. We also show that PECs from Bmpr2 (ΔEx2/+) mice have defects in the BMP-induced Smad1/5/8 and Id1 signaling axis, and that addition of chemical chaperones restores expression of the Smad1/5/8 target Id1. These data indicate that the endogenous NMD negative BMPRΔEx2 mutant product is expressed but has a folding defect resulting in ER retention. Partial correction of this folding defect and restoration of defective BMP signaling using chemical chaperones suggests that protein-folding agents could be used therapeutically in patients with these NMD negative BMPR2 mutations.
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Affiliation(s)
- Andrea L. Frump
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Jonathan W. Lowery
- Department of Developmental Biology, Harvard University School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Rizwan Hamid
- Department of Pediatrics, Division of Molecular Genetics and Genomic Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Eric D. Austin
- Department of Pediatrics, Division of Pediatric Pulmonary Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Mark de Caestecker
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- *E-mail:
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15
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Drake KM, Dunmore BJ, McNelly LN, Morrell NW, Aldred MA. Correction of nonsense BMPR2 and SMAD9 mutations by ataluren in pulmonary arterial hypertension. Am J Respir Cell Mol Biol 2013; 49:403-9. [PMID: 23590310 DOI: 10.1165/rcmb.2013-0100oc] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Heritable pulmonary arterial hypertension (HPAH) is a serious lung vascular disease caused by heterozygous mutations in the bone morphogenetic protein (BMP) pathway genes, BMPR2 and SMAD9. One noncanonical function of BMP signaling regulates biogenesis of a subset of microRNAs. We have previously shown that this function is abrogated in patients with HPAH, making it a highly sensitive readout of BMP pathway integrity. Ataluren (PTC124) is an investigational drug that permits ribosomal readthrough of premature stop codons, resulting in a full-length protein. It exhibits oral bioavailability and limited toxicity in human trials. Here, we tested ataluren in lung- or blood-derived cells from patients with HPAH with nonsense mutations in BMPR2 (n = 6) or SMAD9 (n = 1). Ataluren significantly increased BMP-mediated microRNA processing in six of the seven cases. Moreover, rescue was achieved even for mutations exhibiting significant nonsense-mediated mRNA decay. Response to ataluren was dose dependent, and complete correction was achieved at therapeutic doses currently used in clinical trials for cystic fibrosis. BMP receptor (BMPR)-II protein levels were normalized and ligand-dependent phosphorylation of downstream target Smads was increased. Furthermore, the usually hyperproliferative phenotype of pulmonary artery endothelial and smooth muscle cells was reversed by ataluren. These results indicate that ataluren can effectively suppress a high proportion of BMPR2 and SMAD9 nonsense mutations and correct BMP signaling in vitro. Approximately 29% of all HPAH mutations are nonsense point mutations. In light of this, we propose ataluren as a potential new personalized therapy for this significant subgroup of patients with PAH.
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Affiliation(s)
- Kylie M Drake
- Genomic Medicine Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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16
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Leyton PA, Beppu H, Pappas A, Martyn TM, Derwall M, Baron DM, Galdos R, Bloch DB, Bloch KD. Deletion of the sequence encoding the tail domain of the bone morphogenetic protein type 2 receptor reveals a bone morphogenetic protein 7-specific gain of function. PLoS One 2013; 8:e76947. [PMID: 24116187 PMCID: PMC3792867 DOI: 10.1371/journal.pone.0076947] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 08/27/2013] [Indexed: 11/19/2022] Open
Abstract
The bone morphogenetic protein (BMP) type II receptor (BMPR2) has a long cytoplasmic tail domain whose function is incompletely elucidated. Mutations in the tail domain of BMPR2 are found in familial cases of pulmonary arterial hypertension. To investigate the role of the tail domain of BMPR2 in BMP signaling, we generated a mouse carrying a Bmpr2 allele encoding a non-sense mediated decay-resistant mutant receptor lacking the tail domain of Bmpr2. We found that homozygous mutant mice died during gastrulation, whereas heterozygous mice grew normally without developing pulmonary arterial hypertension. Using pulmonary artery smooth muscle cells (PaSMC) from heterozygous mice, we determined that the mutant receptor was expressed and retained its ability to transduce BMP signaling. Heterozygous PaSMCs exhibited a BMP7‑specific gain of function, which was transduced via the mutant receptor. Using siRNA knockdown and cells from conditional knockout mice to selectively deplete BMP receptors, we observed that the tail domain of Bmpr2 inhibits Alk2‑mediated BMP7 signaling. These findings suggest that the tail domain of Bmpr2 is essential for normal embryogenesis and inhibits Alk2‑mediated BMP7 signaling in PaSMCs.
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MESH Headings
- Activin Receptors, Type I/genetics
- Activin Receptors, Type I/metabolism
- Activin Receptors, Type II/genetics
- Activin Receptors, Type II/metabolism
- Animals
- Binding Sites/genetics
- Bone Morphogenetic Protein 4/pharmacology
- Bone Morphogenetic Protein 7/pharmacology
- Bone Morphogenetic Protein Receptors, Type II/genetics
- Bone Morphogenetic Protein Receptors, Type II/metabolism
- Cells, Cultured
- Familial Primary Pulmonary Hypertension
- Gene Expression/drug effects
- Genotype
- Hypertension, Pulmonary/genetics
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/physiopathology
- Immunoblotting
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Confocal
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Pulmonary Artery/cytology
- RNA Interference
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Deletion
- Smad6 Protein/genetics
- Smad6 Protein/metabolism
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Affiliation(s)
- Patricio A. Leyton
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Hideyuki Beppu
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Clinical Laboratory and Molecular Pathology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Toyama Prefecture, Japan
| | - Alexandra Pappas
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Trejeeve M. Martyn
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Matthias Derwall
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Anesthesiology, Uniklinik Aachen, RWTH Aachen University, Aachen, North Rhine-Westphalia, Germany
| | - David M. Baron
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Anesthesia, General Intensive Care, and Pain Management, Medical University of Vienna, Vienna, Austria
| | - Rita Galdos
- Center for Immunology and Inflammatory Diseases, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Donald B. Bloch
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Center for Immunology and Inflammatory Diseases, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kenneth D. Bloch
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Cardiovascular Research Center, Cardiology Division of the Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
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17
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Fang Y, Bateman JF, Mercer JF, Lamandé SR. Nonsense-mediated mRNA decay of collagen -emerging complexity in RNA surveillance mechanisms. J Cell Sci 2013; 126:2551-60. [PMID: 23729740 DOI: 10.1242/jcs.120220] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is an evolutionarily conserved mRNA surveillance system that degrades mRNA transcripts that harbour a premature translation-termination codon (PTC), thus reducing the synthesis of truncated proteins that would otherwise have deleterious effects. Although extensive research has identified a conserved repertoire of NMD factors, these studies have been performed with a restricted set of genes and gene constructs with relatively few exons. As a consequence, NMD mechanisms are poorly understood for genes with large 3' terminal exons, and the applicability of the current models to large multi-exon genes is not clear. In this Commentary, we present an overview of the current understanding of NMD and discuss how analysis of nonsense mutations in the collagen gene family has provided new mechanistic insights into this process. Although NMD of the collagen genes with numerous small exons is consistent with the widely accepted exon-junction complex (EJC)-dependent model, the degradation of Col10a1 transcripts with nonsense mutations cannot be explained by any of the current NMD models. Col10a1 NMD might represent a fail-safe mechanism for genes that have large 3' terminal exons. Defining the mechanistic complexity of NMD is important to allow us to understand the pathophysiology of the numerous genetic disorders caused by PTC mutations.
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Affiliation(s)
- Yiwen Fang
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville 3052, Australia
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18
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Austin ED, Menon S, Hemnes AR, Robinson LR, Talati M, Fox KL, Cogan JD, Hamid R, Hedges LK, Robbins I, Lane K, Newman JH, Loyd JE, West J. Idiopathic and heritable PAH perturb common molecular pathways, correlated with increased MSX1 expression. Pulm Circ 2012; 1:389-98. [PMID: 22140629 PMCID: PMC3224431 DOI: 10.4103/2045-8932.87308] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The majority of pulmonary arterial hypertension (PAH) is not associated with BMPR2 mutation, and major risk factors for idiopathic PAH are not known. The objective of this study was to identify a gene expression signature for IPAH. To accomplish this, we used Affymetrix arrays to probe expression levels in 86 patient samples, including 22 healthy controls, 20 IPAH patients, 20 heritable PAH patients (HPAH), and 24 BMPR2 mutation carriers that were as yet unaffected (UMC). Culturing the patient cells removes the signatures of drug effects and inflammation which have made interpretation of results from freshly isolated lymphocytes problematic. We found that gene expression signatures from IPAH patients clustered either with HPAH patients or in a single distinct group. There were no groups of genes changed in IPAH that were not also changed in HPAH. HPAH, IPAH, and UMC had common changes in metabolism, actin dynamics, adhesion, cytokines, metabolism, channels, differentiation, and transcription factors. Common to IPAH and HPAH but not UMC were an upregulation of vesicle trafficking, oxidative/nitrosative stress, and cell cycle genes. The transcription factor MSX1, which is known to regulate BMP signaling, was the most upregulated gene (4×) in IPAH patients. These results suggest that IPAH cases have a shared molecular origin, which is closely related to, but distinct from, HPAH. HPAH and IPAH share the majority of altered signaling pathways, suggesting that treatments developed to target the molecular etiology of HPAH will also be effective against IPAH.
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Affiliation(s)
- Eric D Austin
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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19
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Rayson S, Arciga-Reyes L, Wootton L, De Torres Zabala M, Truman W, Graham N, Grant M, Davies B. A role for nonsense-mediated mRNA decay in plants: pathogen responses are induced in Arabidopsis thaliana NMD mutants. PLoS One 2012; 7:e31917. [PMID: 22384098 PMCID: PMC3284524 DOI: 10.1371/journal.pone.0031917] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 01/15/2012] [Indexed: 11/19/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a conserved mechanism that targets aberrant mRNAs for destruction. NMD has also been found to regulate the expression of large numbers of genes in diverse organisms, although the biological role for this is unclear and few evolutionarily conserved targets have been identified. Expression analyses of three Arabidopsis thaliana lines deficient in NMD reveal that the vast majority of NMD-targeted transcripts are associated with response to pathogens. Congruently, NMD mutants, in which these transcripts are elevated, confer partial resistance to Pseudomonas syringae. These findings suggest a biological rationale for the regulation of gene expression by NMD in plants and suggest that manipulation of NMD could offer a new approach for crop protection. Amongst the few non-pathogen responsive NMD-targeted genes, one potential NMD targeted signal, the evolutionarily conserved upstream open reading frame (CuORF), was found to be hugely over-represented, raising the possibility that this feature could be used to target specific physiological mRNAs for control by NMD.
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Affiliation(s)
- Samantha Rayson
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Luis Arciga-Reyes
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Lucie Wootton
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | | | - William Truman
- School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Neil Graham
- Nottingham Arabidopsis Stock Centre, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| | - Murray Grant
- School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Brendan Davies
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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Abstract
Familial pulmonary arterial hypertension (FPAH) was described 60 years ago, but real progress in understanding its origins and pathogenesis is just beginning. Germline mutations in bone morphogenetic protein receptor type 2 (BMPR2) are responsible for the disease in most families, and also in many sporadic cases of idiopathic PAH. Heritable PAH refers to patients with a positive family history, or with a responsible genetic mutation, and is an autosomal dominant disease that affects females disproportionately, may occur at any age, and is characterized by reduced penetrance and variable expressivity. These characteristics suggest that other endogenous or exogenous factors modify its expression. Several different factors have recently been demonstrated to modify the clinical expression of BMPR2 mutation, including estrogen metabolites and functional polymorphisms in transforming growth factor-β1 and CYP1B1. Furthermore, a linkage study recently identified modifier loci for BMPR2 clinical expression, which suggests an oligogenic model. Clinical testing for BMPR2 mutations is available for families with heritable and idiopathic PAH, and is an evolving model of personalized medicine. Variable age of onset and decreased penetrance confound genetic counseling, because the majority of carriers of a BMPR2 mutation will never develop PAH, but often transmit the risk to their progeny.
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