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Waldock WJ, Taylor LJ, Sperring S, Staurenghi F, Martinez-Fernandez de la Camara C, Whitfield J, Clouston P, Yusuf IH, MacLaren RE. A hypomorphic variant of choroideremia is associated with a novel intronic mutation that leads to exon skipping. Ophthalmic Genet 2024; 45:210-217. [PMID: 38273808 DOI: 10.1080/13816810.2023.2270554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/09/2023] [Indexed: 01/27/2024]
Abstract
INTRODUCTION Molecular confirmation of pathogenic sequence variants in the CHM gene is required prior to enrolment in retinal gene therapy clinical trials for choroideremia. Individuals with mild choroideremia have been reported. The molecular basis of genotype-phenotype associations is of clinical relevance since it may impact on selection for retinal gene therapy. METHODS AND MATERIALS Genetic testing and RNA analysis were undertaken in a patient with mild choroideremia to confirm the pathogenicity of a novel intronic variant in CHM and to explore the mechanism underlying the mild clinical phenotype. RESULTS A 42-year-old male presented with visual field loss. Fundoscopy and autofluorescence imaging demonstrated mild choroideremia for his age. Genetic analysis revealed a variant at a splice acceptor site in the CHM gene (c.1350-3C > G). RNA analysis demonstrated two out-of-frame transcripts, suggesting pathogenicity, without any detectable wildtype transcripts. One of the two out-of-frame transcripts is present in very low levels in healthy controls. DISCUSSION Mild choroideremia may result from +3 or -3 splice site variants in CHM. It is presumed that the resulting mRNA transcripts may be partly functional, thereby preventing the development of the null phenotype. Choroideremia patients with such variants may present challenges for gene therapy since there may be residual transcript activity which could result in long-lasting visual function which is atypical for this disease.
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Affiliation(s)
| | - Laura J Taylor
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sian Sperring
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Federica Staurenghi
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Cristina Martinez-Fernandez de la Camara
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Penny Clouston
- Oxford Regional Genetics Laboratories, Churchill Hospital, Oxford, UK
| | - Imran H Yusuf
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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Genotype-Phenotype Correlations in Human Diseases Caused by Mutations of LINC Complex-Associated Genes: A Systematic Review and Meta-Summary. Cells 2022; 11:cells11244065. [PMID: 36552829 PMCID: PMC9777268 DOI: 10.3390/cells11244065] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Mutations in genes encoding proteins associated with the linker of nucleoskeleton and cytoskeleton (LINC) complex within the nuclear envelope cause different diseases with varying phenotypes including skeletal muscle, cardiac, metabolic, or nervous system pathologies. There is some understanding of the structure of LINC complex-associated proteins and how they interact, but it is unclear how mutations in genes encoding them can cause the same disease, and different diseases with different phenotypes. Here, published mutations in LINC complex-associated proteins were systematically reviewed and analyzed to ascertain whether patterns exist between the genetic sequence variants and clinical phenotypes. This revealed LMNA is the only LINC complex-associated gene in which mutations commonly cause distinct conditions, and there are no clear genotype-phenotype correlations. Clusters of LMNA variants causing striated muscle disease are located in exons 1 and 6, and metabolic disease-associated LMNA variants are frequently found in the tail of lamin A/C. Additionally, exon 6 of the emerin gene, EMD, may be a mutation "hot-spot", and diseases related to SYNE1, encoding nesprin-1, are most often caused by nonsense type mutations. These results provide insight into the diverse roles of LINC-complex proteins in human disease and provide direction for future gene-targeted therapy development.
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Delgadillo DM, Céspedes-Cruz AI, Ríos-Castro E, Rodríguez Maldonado MG, López-Nogueda M, Márquez-Gutiérrez M, Villalobos-Manzo R, Ramírez-Reyes L, Domínguez-Fuentes M, Tapia-Ramírez J. Differential Expression of Proteins in an Atypical Presentation of Autoimmune Lymphoproliferative Syndrome. Int J Mol Sci 2022; 23:5366. [PMID: 35628184 PMCID: PMC9140392 DOI: 10.3390/ijms23105366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/02/2022] [Accepted: 05/03/2022] [Indexed: 02/04/2023] Open
Abstract
Autoimmune lymphoproliferative syndrome (ALPS) is a rare disease defined as a defect in the lymphocyte apoptotic pathway. Currently, the diagnosis of ALPS is based on clinical aspects, defective lymphocyte apoptosis and mutations in Fas, FasL and Casp 10 genes. Despite this, ALPS has been misdiagnosed. The aim of this work was to go one step further in the knowledge of the disease, through a molecular and proteomic analysis of peripheral blood mononuclear cells (PBMCs) from two children, a 13-year-old girl and a 6-year-old boy, called patient 1 and patient 2, respectively, with clinical data supporting the diagnosis of ALPS. Fas, FasL and Casp10 genes from both patients were sequenced, and a sample of the total proteins from patient 1 was analyzed by label-free proteomics. Pathway analysis of deregulated proteins from PBMCs was performed on the STRING and PANTHER bioinformatics databases. A mutation resulting in an in-frame premature stop codon and protein truncation was detected in the Fas gene from patient 2. From patient 1, the proteomic analysis showed differences in the level of expression of proteins involved in, among other processes, cell cycle, regulation of cell cycle arrest and immune response. Noticeably, the most down-regulated protein is an important regulator of the cell cycle process. This could be an explanation of the disease in patient 1.
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Affiliation(s)
- Dulce María Delgadillo
- Unidad de Genómica, Proteómica y Metabolómica, Laboratorio Nacional de Servicios Experimentales (LaNSE), Centro de Investigación y de Estudios Avanzados, Mexico City 07360, CP, Mexico
| | - Adriana Ivonne Céspedes-Cruz
- Unidad Médica de Alta Especialidad (UMAE), Centro Médico Nacional La Raza Hospital General, Mexico City 02990, CP, Mexico
| | - Emmanuel Ríos-Castro
- Unidad de Genómica, Proteómica y Metabolómica, Laboratorio Nacional de Servicios Experimentales (LaNSE), Centro de Investigación y de Estudios Avanzados, Mexico City 07360, CP, Mexico
| | | | - Mariel López-Nogueda
- Unidad Médica de Alta Especialidad (UMAE), Centro Médico Nacional La Raza Hospital General, Mexico City 02990, CP, Mexico
| | - Miguel Márquez-Gutiérrez
- Unidad Médica de Alta Especialidad (UMAE), Centro Médico Nacional La Raza Hospital General, Mexico City 02990, CP, Mexico
| | - Rocío Villalobos-Manzo
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados, Mexico City 07360, CP, Mexico
| | - Lorena Ramírez-Reyes
- Unidad de Genómica, Proteómica y Metabolómica, Laboratorio Nacional de Servicios Experimentales (LaNSE), Centro de Investigación y de Estudios Avanzados, Mexico City 07360, CP, Mexico
| | - Misael Domínguez-Fuentes
- Unidad de Genómica, Proteómica y Metabolómica, Laboratorio Nacional de Servicios Experimentales (LaNSE), Centro de Investigación y de Estudios Avanzados, Mexico City 07360, CP, Mexico
| | - José Tapia-Ramírez
- Unidad de Genómica, Proteómica y Metabolómica, Laboratorio Nacional de Servicios Experimentales (LaNSE), Centro de Investigación y de Estudios Avanzados, Mexico City 07360, CP, Mexico
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados, Mexico City 07360, CP, Mexico
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González-Jamett A, Vásquez W, Cifuentes-Riveros G, Martínez-Pando R, Sáez JC, Cárdenas AM. Oxidative Stress, Inflammation and Connexin Hemichannels in Muscular Dystrophies. Biomedicines 2022; 10:biomedicines10020507. [PMID: 35203715 PMCID: PMC8962419 DOI: 10.3390/biomedicines10020507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/13/2022] [Accepted: 02/15/2022] [Indexed: 12/16/2022] Open
Abstract
Muscular dystrophies (MDs) are a heterogeneous group of congenital neuromuscular disorders whose clinical signs include myalgia, skeletal muscle weakness, hypotonia, and atrophy that leads to progressive muscle disability and loss of ambulation. MDs can also affect cardiac and respiratory muscles, impairing life-expectancy. MDs in clude Duchenne muscular dystrophy, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy and limb-girdle muscular dystrophy. These and other MDs are caused by mutations in genes that encode proteins responsible for the structure and function of skeletal muscles, such as components of the dystrophin-glycoprotein-complex that connect the sarcomeric-actin with the extracellular matrix, allowing contractile force transmission and providing stability during muscle contraction. Consequently, in dystrophic conditions in which such proteins are affected, muscle integrity is disrupted, leading to local inflammatory responses, oxidative stress, Ca2+-dyshomeostasis and muscle degeneration. In this scenario, dysregulation of connexin hemichannels seem to be an early disruptor of the homeostasis that further plays a relevant role in these processes. The interaction between all these elements constitutes a positive feedback loop that contributes to the worsening of the diseases. Thus, we discuss here the interplay between inflammation, oxidative stress and connexin hemichannels in the progression of MDs and their potential as therapeutic targets.
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Affiliation(s)
- Arlek González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (W.V.); (J.C.S.)
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile; (G.C.-R.); (R.M.-P.)
- Correspondence: (A.G.-J.); (A.M.C.)
| | - Walter Vásquez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (W.V.); (J.C.S.)
| | - Gabriela Cifuentes-Riveros
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile; (G.C.-R.); (R.M.-P.)
| | - Rafaela Martínez-Pando
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile; (G.C.-R.); (R.M.-P.)
| | - Juan C. Sáez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (W.V.); (J.C.S.)
| | - Ana M. Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (W.V.); (J.C.S.)
- Correspondence: (A.G.-J.); (A.M.C.)
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Clinical Features of LMNA-Related Cardiomyopathy in 18 Patients and Characterization of Two Novel Variants. J Clin Med 2021; 10:jcm10215075. [PMID: 34768595 PMCID: PMC8584896 DOI: 10.3390/jcm10215075] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 01/11/2023] Open
Abstract
Dilated cardiomyopathy (DCM) refers to a spectrum of heterogeneous myocardial disorders characterized by ventricular dilation and depressed myocardial performance in the absence of hypertension, valvular, congenital, or ischemic heart disease. Mutations in LMNA gene, encoding for lamin A/C, account for 10% of familial DCM. LMNA-related cardiomyopathies are characterized by heterogeneous clinical manifestations that vary from a predominantly structural heart disease, mainly mild-to-moderate left ventricular (LV) dilatation associated or not with conduction system abnormalities, to highly pro-arrhythmic profiles where sudden cardiac death (SCD) occurs as the first manifestation of disease in an apparently normal heart. In the present study, we select, among 77 DCM families referred to our center for genetic counselling and molecular screening, 15 patient heterozygotes for LMNA variants. Segregation analysis in the relatives evidences other eight heterozygous patients. A genotype-phenotype correlation has been performed for symptomatic subjects. Lastly, we perform in vitro functional characterization of two novel LMNA variants using dermal fibroblasts obtained from three heterozygous patients, evidencing significant differences in terms of lamin expression and nuclear morphology. Due to the high risk of SCD that characterizes patients with lamin A/C cardiomyopathy, genetic testing for LMNA gene variants is highly recommended when there is suspicion of laminopathy.
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Skeletal Muscle Mitochondria Dysfunction in Genetic Neuromuscular Disorders with Cardiac Phenotype. Int J Mol Sci 2021; 22:ijms22147349. [PMID: 34298968 PMCID: PMC8307986 DOI: 10.3390/ijms22147349] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/03/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023] Open
Abstract
Mitochondrial dysfunction is considered the major contributor to skeletal muscle wasting in different conditions. Genetically determined neuromuscular disorders occur as a result of mutations in the structural proteins of striated muscle cells and therefore are often combined with cardiac phenotype, which most often manifests as a cardiomyopathy. The specific roles played by mitochondria and mitochondrial energetic metabolism in skeletal muscle under muscle-wasting conditions in cardiomyopathies have not yet been investigated in detail, and this aspect of genetic muscle diseases remains poorly characterized. This review will highlight dysregulation of mitochondrial representation and bioenergetics in specific skeletal muscle disorders caused by mutations that disrupt the structural and functional integrity of muscle cells.
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Ignatieva EV, Ivanova OA, Komarova MY, Khromova NV, Polev DE, Kostareva AA, Sergushichev A, Dmitrieva RI. LMNA Mutations G232E and R482L Cause Dysregulation of Skeletal Muscle Differentiation, Bioenergetics, and Metabolic Gene Expression Profile. Genes (Basel) 2020; 11:E1057. [PMID: 32906763 PMCID: PMC7563596 DOI: 10.3390/genes11091057] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/30/2020] [Accepted: 09/01/2020] [Indexed: 02/06/2023] Open
Abstract
Laminopathies are a family of monogenic multi-system diseases resulting from mutations in the LMNA gene which include a wide range of neuromuscular disorders. Although lamins are expressed in most types of differentiated cells, LMNA mutations selectively affect only specific tissues by mechanisms that remain largely unknown. We have employed the combination of functional in vitro experiments and transcriptome analysis in order to determine how two LMNA mutations associated with different phenotypes affect skeletal muscle development and metabolism. We used a muscle differentiation model based on C2C12 mouse myoblasts genetically modified with lentivirus constructs bearing wild-type human LMNA (WT-LMNA) or R482L-LMNA/G232E-LMNA mutations, linked to familial partial lipodystrophy of the Dunnigan type and muscular dystrophy phenotype accordingly. We have shown that both G232E/R482L-LMNA mutations cause dysregulation in coordination of pathways that control cell cycle dynamics and muscle differentiation. We have also found that R482/G232E-LMNA mutations induce mitochondrial uncoupling and a decrease in glycolytic activity in differentiated myotubes. Both types of alterations may contribute to mutation-induced muscle tissue pathology.
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Affiliation(s)
- Elena V. Ignatieva
- National Almazov Medical Research Centre, Institute of Molecular Biology and Genetics, 197341 Saint-Petersburg, Russia; (E.V.I.); (O.A.I.); (M.Y.K.); (N.V.K.); (A.A.K.)
| | - Oksana A. Ivanova
- National Almazov Medical Research Centre, Institute of Molecular Biology and Genetics, 197341 Saint-Petersburg, Russia; (E.V.I.); (O.A.I.); (M.Y.K.); (N.V.K.); (A.A.K.)
- ITMO University, Information Technologies and Programming Faculty, International Laboratory of Bioinformatics and Genomics, 197101 St. Petersburg, Russia;
| | - Margarita Y. Komarova
- National Almazov Medical Research Centre, Institute of Molecular Biology and Genetics, 197341 Saint-Petersburg, Russia; (E.V.I.); (O.A.I.); (M.Y.K.); (N.V.K.); (A.A.K.)
| | - Natalia V. Khromova
- National Almazov Medical Research Centre, Institute of Molecular Biology and Genetics, 197341 Saint-Petersburg, Russia; (E.V.I.); (O.A.I.); (M.Y.K.); (N.V.K.); (A.A.K.)
| | - Dmitrii E. Polev
- Research Resource Center “Biobank”, St Petersburg State University, 199034 Saint-Petersburg, Russia;
| | - Anna A. Kostareva
- National Almazov Medical Research Centre, Institute of Molecular Biology and Genetics, 197341 Saint-Petersburg, Russia; (E.V.I.); (O.A.I.); (M.Y.K.); (N.V.K.); (A.A.K.)
| | - Alexey Sergushichev
- ITMO University, Information Technologies and Programming Faculty, International Laboratory of Bioinformatics and Genomics, 197101 St. Petersburg, Russia;
| | - Renata I. Dmitrieva
- National Almazov Medical Research Centre, Institute of Molecular Biology and Genetics, 197341 Saint-Petersburg, Russia; (E.V.I.); (O.A.I.); (M.Y.K.); (N.V.K.); (A.A.K.)
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Spitalieri P, Talarico RV, Caioli S, Murdocca M, Serafino A, Girasole M, Dinarelli S, Longo G, Pucci S, Botta A, Novelli G, Zona C, Mango R, Sangiuolo F. Modelling the pathogenesis of Myotonic Dystrophy type 1 cardiac phenotype through human iPSC-derived cardiomyocytes. J Mol Cell Cardiol 2018; 118:95-109. [PMID: 29551391 DOI: 10.1016/j.yjmcc.2018.03.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 12/20/2022]
Abstract
Myotonic Dystrophy type 1 (DM1) is a multisystemic disease, autosomal dominant, caused by a CTG repeat expansion in DMPK gene. We assessed the appropriateness of patient-specific induced pluripotent stem cell-derived cardiomyocytes (CMs) as a model to recapitulate some aspects of the pathogenetic mechanism involving cardiac manifestations in DM1 patients. Once obtained in vitro, CMs have been characterized for their morphology and their functionality. CMs DM1 show intranuclear foci and transcript markers abnormally spliced respect to WT ones, as well as several irregularities in nuclear morphology, probably caused by an unbalanced lamin A/C ratio. Electrophysiological characterization evidences an abnormal profile only in CMs DM1 such that the administration of antiarrythmic drugs to these cells highlights even more the functional defect linked to the disease. Finally, Atomic Force Measurements reveal differences in the biomechanical behaviour of CMs DM1, in terms of frequencies and synchronicity of the beats. Altogether the complex phenotype described in this work, strongly reproduces some aspects of the human DM1 cardiac phenotype. Therefore, the present study provides an in vitro model suggesting novel insights into the mechanisms leading to the development of arrhythmogenesis and dilatative cardiomyopathy to consider when approaching to DM1 patients, especially for the risk assessment of sudden cardiac death (SCD). These data could be also useful in identifying novel biomarkers effective in clinical settings and patient-tailored therapies.
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Affiliation(s)
- Paola Spitalieri
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Rosa V Talarico
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | | | - Michela Murdocca
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | | | | | | | | | - Sabina Pucci
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Annalisa Botta
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Giuseppe Novelli
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Cristina Zona
- I.R.C.C.S. S. Lucia, Rome, Italy; Dept of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | | | - Federica Sangiuolo
- Dept of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.
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Captur G, Arbustini E, Bonne G, Syrris P, Mills K, Wahbi K, Mohiddin SA, McKenna WJ, Pettit S, Ho CY, Muchir A, Gissen P, Elliott PM, Moon JC. Lamin and the heart. Heart 2017; 104:468-479. [DOI: 10.1136/heartjnl-2017-312338] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/17/2017] [Accepted: 10/19/2017] [Indexed: 11/04/2022] Open
Abstract
Lamins A and C are intermediate filament nuclear envelope proteins encoded by the LMNA gene. Mutations in LMNA cause autosomal dominant severe heart disease, accounting for 10% of dilated cardiomyopathy (DCM). Characterised by progressive conduction system disease, arrhythmia and systolic impairment, lamin A/C heart disease is more malignant than other common DCMs due to high event rates even when the left ventricular impairment is mild. It has several phenotypic mimics, but overall it is likely to be an under-recognised cause of DCM. In certain clinical scenarios, particularly familial DCM with early conduction disease, the pretest probability of finding an LMNA mutation may be quite high.Recognising lamin A/C heart disease is important because implantable cardioverter defibrillators need to be implanted early. Promising oral drug therapies are within reach thanks to research into the mitogen-activated protein kinase (MAPK) and affiliated pathways. Personalised heart failure therapy may soon become feasible for LMNA, alongside personalised risk stratification, as variant-related differences in phenotype severity and clinical course are being steadily elucidated.Genotyping and family screening are clinically important both to confirm and to exclude LMNA mutations, but it is the three-pronged integration of such genetic information with functional data from in vivo cardiomyocyte mechanics, and pathological data from microscopy of the nuclear envelope, that is properly reshaping our LMNA knowledge base, one variant at a time. This review explains the biology of lamin A/C heart disease (genetics, structure and function of lamins), clinical presentation (diagnostic pointers, electrocardiographic and imaging features), aspects of screening and management, including current uncertainties, and future directions.
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Lamins and metabolism. Clin Sci (Lond) 2017; 131:105-111. [PMID: 27974395 DOI: 10.1042/cs20160488] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/27/2016] [Accepted: 11/07/2016] [Indexed: 12/22/2022]
Abstract
Lamins are nuclear intermediate filaments (IFs) with important roles in most nuclear activities, including nuclear organization and cell-cycle progression. Mutations in human lamins cause over 17 different diseases, termed laminopathies. Most of these diseases are autosomal dominant and can be roughly divided into four major groups: muscle diseases, peripheral neuronal diseases, accelerated aging disorders and metabolic diseases including Dunnigan type familial partial lipodystrophy (FLPD), acquired partial lipodystrophy (APL) and autosomal dominant leucodystrophy. Mutations in lamins are also associated with the metabolic syndrome (MS). Cells derived from patients suffering from metabolic laminopathies, as well as cells derived from the corresponding animal models, show a disruption of the mechanistic target of rapamycin (mTOR) pathway, abnormal autophagy, altered proliferative rate and down-regulation of genes that regulate adipogenesis. In addition, treating Hutchinson-Gilford progeria syndrome (HGPS) cells with the mTOR inhibitor rapamycin improves their fate. In this review, we will discuss the ways by which lamin genes are involved in the regulation of cell metabolism.
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Corne TDJ, Sieprath T, Vandenbussche J, Mohammed D, Te Lindert M, Gevaert K, Gabriele S, Wolf K, De Vos WH. Deregulation of focal adhesion formation and cytoskeletal tension due to loss of A-type lamins. Cell Adh Migr 2016; 11:447-463. [PMID: 27791462 DOI: 10.1080/19336918.2016.1247144] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The nuclear lamina mechanically integrates the nucleus with the cytoskeleton and extracellular environment and regulates gene expression. These functions are exerted through direct and indirect interactions with the lamina's major constituent proteins, the A-type lamins, which are encoded by the LMNA gene. Using quantitative stable isotope labeling-based shotgun proteomics we have analyzed the proteome of human dermal fibroblasts in which we have depleted A-type lamins by means of a sustained siRNA-mediated LMNA knockdown. Gene ontology analysis revealed that the largest fraction of differentially produced proteins was involved in actin cytoskeleton organization, in particular proteins involved in focal adhesion dynamics, such as actin-related protein 2 and 3 (ACTR2/3), subunits of the ARP2/3 complex, and fascin actin-bundling protein 1 (FSCN1). Functional validation using quantitative immunofluorescence showed a significant reduction in the size of focal adhesion points in A-type lamin depleted cells, which correlated with a reduction in early cell adhesion capacity and an increased cell motility. At the same time, loss of A-type lamins led to more pronounced stress fibers and higher traction forces. This phenotype could not be mimicked or reversed by experimental modulation of the STAT3-IL6 pathway, but it was partly recapitulated by chemical inhibition of the ARP2/3 complex. Thus, our data suggest that the loss of A-type lamins perturbs the balance between focal adhesions and cytoskeletal tension. This imbalance may contribute to mechanosensing defects observed in certain laminopathies.
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Affiliation(s)
- Tobias D J Corne
- a Laboratory of Cell Biology and Histology , Department of Veterinary Sciences, University of Antwerp , Antwerp , Belgium.,b Cell Systems and Imaging Research Group (CSI) , Department of Molecular Biotechnology, Ghent University , Ghent , Belgium
| | - Tom Sieprath
- a Laboratory of Cell Biology and Histology , Department of Veterinary Sciences, University of Antwerp , Antwerp , Belgium.,b Cell Systems and Imaging Research Group (CSI) , Department of Molecular Biotechnology, Ghent University , Ghent , Belgium
| | - Jonathan Vandenbussche
- c Medical Biotechnology Center, VIB , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| | - Danahe Mohammed
- e Mechanobiology & Soft Matter Research Group, Interfaces and Complex Fluids Laboratory, Research Institute for Biosciences, University of Mons , Mons , Belgium
| | - Mariska Te Lindert
- f Department of Cell Biology , Radboud University Medical Center , Nijmegen , The Netherlands
| | - Kris Gevaert
- c Medical Biotechnology Center, VIB , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| | - Sylvain Gabriele
- e Mechanobiology & Soft Matter Research Group, Interfaces and Complex Fluids Laboratory, Research Institute for Biosciences, University of Mons , Mons , Belgium
| | - Katarina Wolf
- f Department of Cell Biology , Radboud University Medical Center , Nijmegen , The Netherlands
| | - Winnok H De Vos
- a Laboratory of Cell Biology and Histology , Department of Veterinary Sciences, University of Antwerp , Antwerp , Belgium.,b Cell Systems and Imaging Research Group (CSI) , Department of Molecular Biotechnology, Ghent University , Ghent , Belgium
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Akinci B, Sankella S, Gilpin C, Ozono K, Garg A, Agarwal AK. Progeroid syndrome patients with ZMPSTE24 deficiency could benefit when treated with rapamycin and dimethylsulfoxide. Cold Spring Harb Mol Case Stud 2016; 3:a001339. [PMID: 28050601 PMCID: PMC5171694 DOI: 10.1101/mcs.a001339] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Patients with progeroid syndromes such as mandibuloacral dysplasia, type B (MADB) and restrictive dermopathy (RD) harbor mutations in zinc metalloproteinase (ZMPSTE24), an enzyme essential for posttranslational proteolysis of prelamin A to form mature lamin A. Dermal fibroblasts from these patients show increased nuclear dysmorphology and reduced proliferation; however, the efficacy of various pharmacological agents in reversing these cellular phenotypes remains unknown. In this study, fibroblasts from MADB patients exhibited marked nuclear abnormalities and reduced proliferation that improved upon treatment with rapamycin and dimethylsulfoxide but not with other agents, including farnesyl transferase inhibitors. Surprisingly, fibroblasts from an RD patient with a homozygous null mutation in ZMPSTE24, resulting in exclusive accumulation of prelamin A with no lamin A on immunoblotting of cellular lysate, exhibited few nuclear abnormalities and near-normal cellular proliferation. An unbiased proteomic analysis of the cellular lysate from RD fibroblasts revealed a lack of processing of vimentin, a cytoskeletal protein. Interestingly, the assembly of the vimentin microfibrils in MADB fibroblasts improved with rapamycin and dimethylsulfoxide. We conclude that rapamycin and dimethylsulfoxide are beneficial for improving nuclear morphology and cell proliferation of MADB fibroblasts. Data from a single RD patient's fibroblasts also suggest that prelamin A accumulation by itself might not be detrimental and requires additional alterations at the cellular level to manifest the phenotype.
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Affiliation(s)
- Baris Akinci
- Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Shireesha Sankella
- Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Christopher Gilpin
- Molecular and Cellular Imaging, Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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Fuller HR, Graham LC, Llavero Hurtado M, Wishart TM. Understanding the molecular consequences of inherited muscular dystrophies: advancements through proteomic experimentation. Expert Rev Proteomics 2016; 13:659-71. [PMID: 27329572 DOI: 10.1080/14789450.2016.1202768] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 06/14/2016] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Proteomic techniques offer insights into the molecular perturbations occurring in muscular-dystrophies (MD). Revisiting published datasets can highlight conserved downstream molecular alterations, which may be worth re-assessing to determine whether their experimental manipulation is capable of modulating disease severity. AREAS COVERED Here, we review the MD literature, highlighting conserved molecular insights warranting mechanistic investigation for therapeutic potential. We also describe a workflow currently proving effective for efficient identification of biomarkers & therapeutic targets in other neurodegenerative conditions, upon which future MD proteomic investigations could be modelled. Expert commentary: Studying disease models can be useful for identifying biomarkers and model specific degenerative cascades, but rarely offer translatable mechanistic insights into disease pathology. Conversely, direct analysis of human samples undergoing degeneration presents challenges derived from complex chronic degenerative molecular processes. This requires a carefully planed & reproducible experimental paradigm accounting for patient selection through to grouping by disease severity and ending with proteomic data filtering and processing.
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Affiliation(s)
- Heidi R Fuller
- a Wolfson Centre for Inherited Neuromuscular Disease , RJAH Orthopaedic Hospital , Oswestry , UK
- b Institute for Science and Technology in Medicine , Keele University , Staffordshire , UK
| | - Laura C Graham
- c Euan MacDonald Centre for Motor Neurone Disease Research , University of Edinburgh , Edinburgh , UK
- d Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies , University of Edinburgh , Edinburgh , UK
| | - Maica Llavero Hurtado
- c Euan MacDonald Centre for Motor Neurone Disease Research , University of Edinburgh , Edinburgh , UK
- d Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies , University of Edinburgh , Edinburgh , UK
| | - Thomas M Wishart
- c Euan MacDonald Centre for Motor Neurone Disease Research , University of Edinburgh , Edinburgh , UK
- d Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies , University of Edinburgh , Edinburgh , UK
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Calcium signaling-related proteins are associated with broncho-pulmonary dysplasia progression. J Proteomics 2013; 94:401-12. [DOI: 10.1016/j.jprot.2013.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/04/2013] [Accepted: 10/05/2013] [Indexed: 02/07/2023]
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Current World Literature. Curr Opin Cardiol 2013; 28:369-79. [DOI: 10.1097/hco.0b013e328360f5be] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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