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Pousada G, Baloira A, Valverde D. Molecular and clinical analysis of TRPC6 and AGTR1 genes in patients with pulmonary arterial hypertension. Orphanet J Rare Dis 2015; 10:1. [PMID: 25603901 PMCID: PMC4307182 DOI: 10.1186/s13023-014-0216-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/17/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is a rare and progressive vascular disorder characterized by increased pulmonary vascular resistance and right heart failure. The aim of this study was to analyze 5'UTR region in canonical transient receptor potential isoform 6 (TRPC6) and 3'UTR region in Angiotensin II type I receptor (AGTR1) genes in patients with idiopathic and associated PAH. Correlation among mutations and clinical and functional parameters was further analyzed. METHODS Analysis of TRPC6 and AGTR1 genes was performed by polymerase chain reaction (PCR) and direct sequencing. We used a non-parametric test to determine if significant differences were found between the groups studied and chi-square test to compare clinical and hemodynamic variables among genotypes. RESULTS Fifty five patients and fifty two controls were included in this study. We found statistically significant differences for c.1-361A > T (p = 0.0077), c.1-254C > G (p < 0.0001) and c.1-218C > T (p = 0.0021) in TRPC6 gene and c.1166A > C (p < 0.001) in AGTR1 gene, between patients and controls. Idiopathic PAH patients (IPAH) and controls presented significant differences for all 3 TRPC6 polymorphisms (p = 0.020), (p = 0.002) and (p = 0.008) respectively, and also showed differences for AGTR1 gene (p < 0.001). In associated PAH (APAH) patients we found statistical differences for c.1-254C > G (p < 0.001) and c.1-218C > T (p = 0.001) in TRPC6 gene and c.1166A > C (p = 0.001) in AGTR1 gene. Several clinical and hemodynamic parameters showed significant differences between carriers and non-carriers of these single nucleotide polymorphisms (SNPs). Nineteen patients were carriers of all 3 SNPs in TRPC6 gene and presented a more severe phenotype with differences in mean pulmonary arterial pressure (p = 0.016), systolic pulmonary arterial pressure (p = 0.040), cardiac index (p < 0.001) and 6 minute walking test (p = 0.049). 16 of these patients harbored the SNP in AGTR1 gene. These patients showed differences in age at diagnosis (p = 0.049), mean pulmonary arterial pressure (p = 0.033), cardiac index (p = 0.002) and 6 minute walking test (p = 0.039). CONCLUSIONS PAH is a rare disease with pulmonary vascular remodeling caused in part by a heterogeneous constellation of genetic arrangements. This study seems to suggest that c.1-361A > T, c.1-254C > G and c.1-218C > T polymorphisms in TRPC6 gene and c.1166A > C polymorphism in AGTR1 could have a role in the development of this disease.
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Affiliation(s)
- Guillermo Pousada
- Department Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Campus As Lagoas Marcosende S/N, 36310, Vigo, Spain. .,Instituto de Investigación Biomédica de Vigo (IBIV), Vigo, Spain.
| | - Adolfo Baloira
- Complexo Hospitalario Universitario de Pontevedra, Servicio de Neumología, Pontevedra, Spain.
| | - Diana Valverde
- Department Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Campus As Lagoas Marcosende S/N, 36310, Vigo, Spain. .,Instituto de Investigación Biomédica de Vigo (IBIV), Vigo, Spain.
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Machado RD, Eickelberg O, Elliott CG, Geraci MW, Hanaoka M, Loyd JE, Newman JH, Phillips JA, Soubrier F, Trembath RC, Chung WK. Genetics and genomics of pulmonary arterial hypertension. J Am Coll Cardiol 2009; 54:S32-S42. [PMID: 19555857 DOI: 10.1016/j.jacc.2009.04.015] [Citation(s) in RCA: 255] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 04/15/2009] [Indexed: 11/17/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a rare disorder that may be hereditable (HPAH), idiopathic (IPAH), or associated with either drug-toxin exposures or other medical conditions. Familial cases have long been recognized and are usually due to mutations in the bone morphogenetic protein receptor type 2 gene (BMPR2), or, much less commonly, 2 other members of the transforming growth factor-beta superfamily, activin-like kinase-type 1 (ALK1) and endoglin (ENG), which are associated with hereditary hemorrhagic telangiectasia. In addition, approximately 20% of patients with IPAH carry mutations in BMPR2. We provide a summary of BMPR2 mutations associated with HPAH, most of which are unique to each family and are presumed to result in loss of function. We review the finding of missense variants and variants of unknown significance in BMPR2 in IPAH/HPAH, fenfluramine exposure, and PAH associated with congenital heart disease. Clinical testing for BMPR2 mutations is available and may be offered to HPAH and IPAH patients but should be preceded by genetic counseling, since lifetime penetrance is only 10% to 20%, and there are currently no known effective preventative measures. Identification of a familial mutation can be valuable in reproductive planning and identifying family members who are not mutation carriers and thus will not require lifelong surveillance. With advances in genomic technology and with international collaborative efforts, genome-wide association studies will be conducted to identify additional genes for HPAH, genetic modifiers for BMPR2 penetrance and genetic susceptibility to IPAH. In addition, collaborative studies of BMPR2 mutation carriers should enable identification of environmental modifiers, biomarkers for disease development and progression, and surrogate markers for efficacy end points in clinical drug development, thereby providing an invaluable resource for trials of PAH prevention.
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Affiliation(s)
- Rajiv D Machado
- Department of Medical and Molecular Genetics, King's College London School of Medicine, Guy's Hospital, London, United Kingdom.
| | - Oliver Eickelberg
- Comprehensive Pneumology Center, Ludwig-Maximilians-Universität, Asklepios Klinik Gauting und Helmholtz Zentrum München, and Institute of Lung Biology and Disease (iLBD), Helmholtz Zentrum München, Munich, Germany
| | - C Gregory Elliott
- Departments of Medicine, Intermountain Medical Center and the University of Utah School of Medicine, Salt Lake City, Utah
| | - Mark W Geraci
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center, Denver, Colorado
| | - Masayuki Hanaoka
- First Department of Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - James E Loyd
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - John H Newman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - John A Phillips
- Department of Pediatrics and Division of Medical Genetics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Florent Soubrier
- Faculté de Medicine, Université Paris 6, Hôpital Pitié-Salpêtrière, Paris, France
| | - Richard C Trembath
- Department of Medical and Molecular Genetics, King's College London School of Medicine, Guy's Hospital, London, United Kingdom
| | - Wendy K Chung
- Departments of Pediatrics and Medicine, Columbia University College of Physicians & Surgeons, New York, New York
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Dempsie Y, MacLean MR. Pulmonary hypertension: therapeutic targets within the serotonin system. Br J Pharmacol 2008; 155:455-62. [PMID: 18536742 DOI: 10.1038/bjp.2008.241] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is characterized by a sustained and progressive elevation in pulmonary arterial pressure and pulmonary vascular remodelling leading to right heart failure and death. Prognosis is poor and novel therapeutic approaches are needed. The serotonin hypothesis of PAH originated in the 1960s after an outbreak of the disease was reported among patients taking the anorexigenic drugs aminorex and fenfluramine. These are indirect serotonergic agonists and serotonin transporter substrates. Since then many advances have been made in our understanding of the role of serotonin in the pathobiology of PAH. The rate-limiting enzyme in the synthesis of serotonin is tryptophan hydroxylase (Tph). Serotonin is synthesized, through Tph1, in the endothelial cells of the pulmonary artery and can then act on underlying pulmonary arterial smooth muscle cells and pulmonary arterial fibroblasts in a paracrine fashion causing constriction and remodelling. These effects of serotonin can be mediated through both the serotonin transporter and serotonin receptors. This review will discuss our current understanding of 'the serotonin hypothesis' of PAH and highlight possible therapeutic targets within the serotonin system.
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Affiliation(s)
- Y Dempsie
- Division of Neuroscience and Biomedical Systems, Institute of Biomedical Sciences, University of Glasgow, Scotland, UK.
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