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Polavarapu K, O'Neil D, Thompson R, Spendiff S, Nandeesh B, Vengalil S, Huddar A, Baskar D, Arunachal G, Kotambail A, Bhatia S, Tumulu SK, Matalonga L, Töpf A, Laurie S, Zeldin J, Nashi S, Unnikrishnan G, Nalini A, Lochmüller H. Partial loss of desmin expression due to a leaky splice site variant in the human DES gene is associated with neuromuscular transmission defects. Neuromuscul Disord 2024; 39:10-18. [PMID: 38669730 DOI: 10.1016/j.nmd.2024.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 02/15/2024] [Accepted: 03/20/2024] [Indexed: 04/28/2024]
Abstract
Recessive desminopathies are rare and often present as severe early-onset myopathy. Here we report a milder phenotype in three unrelated patients from southern India (2 M, 1F) aged 16, 21, and 22 years, who presented with childhood-onset, gradually progressive, fatigable limb-girdle weakness, ptosis, speech and swallowing difficulties, without cardiac involvement. Serum creatine kinase was elevated, and repetitive nerve stimulation showed decrement in all. Clinical improvement was noted with pyridostigmine and salbutamol in two patients. All three patients had a homozygous substitution in intron 5: DES(NM_001927.4):c.1023+5G>A, predicted to cause a donor splice site defect. Muscle biopsy with ultrastructural analysis suggested myopathy with myofibrillar disarray, and immunohistochemistry showed partial loss of desmin with some residual staining, while western blot analysis showed reduced desmin. RT-PCR of patient muscle RNA revealed two transcripts: a reduced normal desmin transcript and a larger abnormal transcript suggesting leaky splicing at the intron 5 donor site. Sequencing of the PCR products confirmed the inclusion of intron 5 in the longer transcript, predicted to cause a premature stop codon. Thus, we provide evidence for a leaky splice site causing partial loss of desmin associated with a unique phenotypic presentation of a milder form of desmin-related recessive myopathy overlapping with congenital myasthenic syndrome.
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Affiliation(s)
- Kiran Polavarapu
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Daniel O'Neil
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Rachel Thompson
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Sally Spendiff
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Bevinahalli Nandeesh
- Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Akshata Huddar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Dipti Baskar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Gautham Arunachal
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | | | - Saloni Bhatia
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Seetam Kumar Tumulu
- Department of Neuroradiology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Leslie Matalonga
- Centro Nacional de Análisis Genómico, Baldiri Reixac 4, Barcelona 08028, Spain
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Steven Laurie
- Centro Nacional de Análisis Genómico, Baldiri Reixac 4, Barcelona 08028, Spain
| | - Joshua Zeldin
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Saraswati Nashi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | | | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India.
| | - Hanns Lochmüller
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada; Centro Nacional de Análisis Genómico, Baldiri Reixac 4, Barcelona 08028, Spain; Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada; Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada; Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.
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2
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Politano L. Is Cardiac Transplantation Still a Contraindication in Patients with Muscular Dystrophy-Related End-Stage Dilated Cardiomyopathy? A Systematic Review. Int J Mol Sci 2024; 25:5289. [PMID: 38791328 PMCID: PMC11121328 DOI: 10.3390/ijms25105289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 05/05/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Inherited muscular diseases (MDs) are genetic degenerative disorders typically caused by mutations in a single gene that affect striated muscle and result in progressive weakness and wasting in affected individuals. Cardiac muscle can also be involved with some variability that depends on the genetic basis of the MD (Muscular Dystrophy) phenotype. Heart involvement can manifest with two main clinical pictures: left ventricular systolic dysfunction with evolution towards dilated cardiomyopathy and refractory heart failure, or the presence of conduction system defects and serious life-threatening ventricular arrhythmias. The two pictures can coexist. In these cases, heart transplantation (HTx) is considered the most appropriate option in patients who are not responders to the optimized standard therapeutic protocols. However, cardiac transplant is still considered a relative contraindication in patients with inherited muscle disorders and end-stage cardiomyopathies. High operative risk related to muscle impairment and potential graft involvement secondary to the underlying myopathy have been the two main reasons implicated in the generalized reluctance to consider cardiac transplant as a viable option. We report an overview of cardiac involvement in MDs and its possible association with the underlying molecular defect, as well as a systematic review of HTx outcomes in patients with MD-related end-stage dilated cardiomyopathy, published so far in the literature.
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Affiliation(s)
- Luisa Politano
- Cardiomyology and Medical Genetics, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
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3
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Geist Hauserman J, Laverty CG, Donkervoort S, Hu Y, Silverstein S, Neuhaus SB, Saade D, Vaughn G, Malicki D, Kaur R, Li Y, Luo Y, Liu P, Burr P, Foley AR, Mohassel P, Bönnemann CG. Clinical, immunohistochemical, and genetic characterization of splice-altering biallelic DES variants: Therapeutic implications. HGG ADVANCES 2024; 5:100274. [PMID: 38358893 PMCID: PMC10876619 DOI: 10.1016/j.xhgg.2024.100274] [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: 11/09/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/17/2024] Open
Abstract
Pathogenic variants in the DES gene clinically manifest as progressive skeletal muscle weakness, cardiomyopathy with associated severe arrhythmias, and respiratory insufficiency, and are collectively known as desminopathies. While most DES pathogenic variants act via a dominant mechanism, recessively acting variants have also been reported. Currently, there are no effective therapeutic interventions for desminopathies of any type. Here, we report an affected individual with rapidly progressive dilated cardiomyopathy, requiring heart transplantation at age 13 years, in the setting of childhood-onset skeletal muscle weakness. We identified biallelic DES variants (c.640-13 T>A and c.1288+1 G>A) and show aberrant DES gene splicing in the affected individual's muscle. Through the generation of an inducible lentiviral system, we transdifferentiated fibroblast cultures derived from the affected individual into myoblasts and validated this system using RNA sequencing. We tested rationally designed, custom antisense oligonucleotides to screen for splice correction in these transdifferentiated cells and a functional minigene splicing assay. However, rather than correctly redirecting splicing, we found them to induce undesired exon skipping. Our results indicate that, while an individual precision-based molecular therapeutic approach to splice-altering pathogenic variants is promising, careful preclinical testing is imperative for each novel variant to test the feasibility of this type of approach for translation.
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Affiliation(s)
- Janelle Geist Hauserman
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA.
| | | | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Ying Hu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Sarah Silverstein
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Sarah B Neuhaus
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Dimah Saade
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | | | | | - Rupleen Kaur
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Yuesheng Li
- DNA Sequencing and Genomics Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Yan Luo
- DNA Sequencing and Genomics Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Poching Liu
- DNA Sequencing and Genomics Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Patrick Burr
- DNA Sequencing and Genomics Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Payam Mohassel
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA.
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4
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Onore ME, Savarese M, Picillo E, Passamano L, Nigro V, Politano L. Bi-Allelic DES Gene Variants Causing Autosomal Recessive Myofibrillar Myopathies Affecting Both Skeletal Muscles and Cardiac Function. Int J Mol Sci 2022; 23:ijms232415906. [PMID: 36555543 PMCID: PMC9785402 DOI: 10.3390/ijms232415906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/09/2022] [Accepted: 12/11/2022] [Indexed: 12/15/2022] Open
Abstract
Mutations in the human desmin gene (DES) may cause both autosomal dominant and recessive cardiomyopathies leading to heart failure, arrhythmias and atrio-ventricular blocks, or progressive myopathies. Cardiac conduction disorders, arrhythmias and cardiomyopathies usually associated with progressive myopathy are the main manifestations of autosomal dominant desminopathies, due to mono-allelic pathogenic variants. The recessive forms, due to bi-allelic variants, are very rare and exhibit variable phenotypes in which premature sudden cardiac death could also occur in the first or second decade of life. We describe a further case of autosomal recessive desminopathy in an Italian boy born of consanguineous parents, who developed progressive myopathy at age 12, and dilated cardiomyopathy four years later and died of intractable heart failure at age 17. Next Generation Sequencing (NGS) analysis identified the homozygous loss-of-function variant c.634C>T; p.Arg212*, which was likely inherited from both parents. Furthermore, we performed a comparison of clinical and genetic results observed in our patient with those of cases so far reported in the literature.
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Affiliation(s)
- Maria Elena Onore
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Marco Savarese
- Folkhälsan Research Center, 00280 Helsinki, Finland
- Department of Medical and Clinical Genetics, Medicum, University of Helsinki, 00280 Helsinki, Finland
| | - Esther Picillo
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Luigia Passamano
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Vincenzo Nigro
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Luisa Politano
- Cardiomyology and Medical Genetics, Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Correspondence:
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5
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The N-Terminal Part of the 1A Domain of Desmin Is a Hot Spot Region for Putative Pathogenic DES Mutations Affecting Filament Assembly. Cells 2022; 11:cells11233906. [PMID: 36497166 PMCID: PMC9738904 DOI: 10.3390/cells11233906] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 11/29/2022] [Indexed: 12/09/2022] Open
Abstract
Desmin is the major intermediate filament protein of all three muscle cell types, and connects different cell organelles and multi-protein complexes such as the cardiac desmosomes. Several pathogenic mutations in the DES gene cause different skeletal and cardiac myopathies. However, the significance of the majority of DES missense variants is currently unknown, since functional data are lacking. To determine whether desmin missense mutations within the highly conserved 1A coil domain cause a filament assembly defect, we generated a set of variants with unknown significance and systematically analyzed the filament assembly using confocal microscopy in transfected SW-13, H9c2 cells and cardiomyocytes derived from induced pluripotent stem cells. We found that mutations in the N-terminal part of the 1A coil domain affect filament assembly, leading to cytoplasmic desmin aggregation. In contrast, mutant desmin in the C-terminal part of the 1A coil domain forms filamentous structures comparable to wild-type desmin. Our findings suggest that the N-terminal part of the 1A coil domain is a hot spot for pathogenic desmin mutations, which affect desmin filament assembly. This study may have relevance for the genetic counselling of patients carrying variants in the 1A coil domain of the DES gene.
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Desmin Knock-Out Cardiomyopathy: A Heart on the Verge of Metabolic Crisis. Int J Mol Sci 2022; 23:ijms231912020. [PMID: 36233322 PMCID: PMC9570457 DOI: 10.3390/ijms231912020] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/30/2022] [Accepted: 10/02/2022] [Indexed: 12/05/2022] Open
Abstract
Desmin mutations cause familial and sporadic cardiomyopathies. In addition to perturbing the contractile apparatus, both desmin deficiency and mutated desmin negatively impact mitochondria. Impaired myocardial metabolism secondary to mitochondrial defects could conceivably exacerbate cardiac contractile dysfunction. We performed metabolic myocardial phenotyping in left ventricular cardiac muscle tissue in desmin knock-out mice. Our analyses revealed decreased mitochondrial number, ultrastructural mitochondrial defects, and impaired mitochondria-related metabolic pathways including fatty acid transport, activation, and catabolism. Glucose transporter 1 and hexokinase-1 expression and hexokinase activity were increased. While mitochondrial creatine kinase expression was reduced, fetal creatine kinase expression was increased. Proteomic analysis revealed reduced expression of proteins involved in electron transport mainly of complexes I and II, oxidative phosphorylation, citrate cycle, beta-oxidation including auxiliary pathways, amino acid catabolism, and redox reactions and oxidative stress. Thus, desmin deficiency elicits a secondary cardiac mitochondriopathy with severely impaired oxidative phosphorylation and fatty and amino acid metabolism. Increased glucose utilization and fetal creatine kinase upregulation likely portray attempts to maintain myocardial energy supply. It may be prudent to avoid medications worsening mitochondrial function and other metabolic stressors. Therapeutic interventions for mitochondriopathies might also improve the metabolic condition in desmin deficient hearts.
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7
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Claes L, Schil KV, Dewals W, Beysen D. A Severe Form of Familial Desminopathy Due to a Homozygous Nonsense DES Variant in Two Siblings. Neuropediatrics 2022. [PMID: 35675837 DOI: 10.1055/a-1871-3692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Familial primary desminopathies are usually autosomal dominantly inherited and present at the age of 20 to 40 years with progressive muscle weakness and atrophy, cardiomyopathy, and cardiac arrhythmias. Cardiac features may precede the muscular weakness. Here, we report the rare case of two siblings presenting with a desminopathy at pediatric age, due to homozygous nonsense variations (c.700G > T [p.Glu234Ter]) in DES, representing an autosomal recessive inheritance pattern. The homozygous state of these variants is expected to result in the complete absence of desmin production. Rare autosomal recessive DES variants are associated with an earlier clinical presentation (from childhood to early adulthood) and faster evolution compared with more common autosomal dominant variants. A normal resting electrocardiography (ECG) and cardiac ultrasound can be a pitfall, as seen in our patient who has extensive fibrotic scarring on cardiac magnetic resonance imaging (MRI). We recommend yearly cardiac ultrasound, yearly 24-hour Holter monitoring and 2 yearly cardiac MRI from the age of 10 years in all asymptomatic patients. Heterozygous patients usually have no or only mild complaints but, though not yet reported in autosomal recessive desminopathies, muscular complaints are possible, as seen in the father of our patients. The prognosis for these patients with desminopathy presenting in childhood is unpredictable but anticipated as poor.
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Affiliation(s)
- Laura Claes
- Department of Paediatric Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Kristof van Schil
- Department of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.,Department of Medical Genetics, Antwerp University Hospital, Antwerp, Belgium
| | - Wendy Dewals
- Department of Paediatric Cardiology, Antwerp University Hospital, Antwerp, Belgium
| | - Diane Beysen
- Department of Paediatric Neurology, Antwerp University Hospital, Antwerp, Belgium.,Department of Paediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
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8
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Herrmann H, Cabet E, Chevalier NR, Moosmann J, Schultheis D, Haas J, Schowalter M, Berwanger C, Weyerer V, Agaimy A, Meder B, Müller OJ, Katus HA, Schlötzer-Schrehardt U, Vicart P, Ferreiro A, Dittrich S, Clemen CS, Lilienbaum A, Schröder R. Dual Functional States of R406W-Desmin Assembly Complexes Cause Cardiomyopathy With Severe Intercalated Disc Derangement in Humans and in Knock-In Mice. Circulation 2020; 142:2155-2171. [PMID: 33023321 DOI: 10.1161/circulationaha.120.050218] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Mutations in the human desmin gene cause myopathies and cardiomyopathies. This study aimed to elucidate molecular mechanisms initiated by the heterozygous R406W-desmin mutation in the development of a severe and early-onset cardiac phenotype. METHODS We report an adolescent patient who underwent cardiac transplantation as a result of restrictive cardiomyopathy caused by a heterozygous R406W-desmin mutation. Sections of the explanted heart were analyzed with antibodies specific to 406W-desmin and to intercalated disc proteins. Effects of the R406W mutation on the molecular properties of desmin were addressed by cell transfection and in vitro assembly experiments. To prove the genuine deleterious effect of the mutation on heart tissue, we further generated and analyzed R405W-desmin knock-in mice harboring the orthologous form of the human R406W-desmin. RESULTS Microscopic analysis of the explanted heart revealed desmin aggregates and the absence of desmin filaments at intercalated discs. Structural changes within intercalated discs were revealed by the abnormal organization of desmoplakin, plectin, N-cadherin, and connexin-43. Next-generation sequencing confirmed the DES variant c.1216C>T (p.R406W) as the sole disease-causing mutation. Cell transfection studies disclosed a dual behavior of R406W-desmin with both its integration into the endogenous intermediate filament system and segregation into protein aggregates. In vitro, R406W-desmin formed unusually thick filaments that organized into complex filament aggregates and fibrillar sheets. In contrast, assembly of equimolar mixtures of mutant and wild-type desmin generated chimeric filaments of seemingly normal morphology but with occasional prominent irregularities. Heterozygous and homozygous R405W-desmin knock-in mice develop both a myopathy and a cardiomyopathy. In particular, the main histopathologic results from the patient are recapitulated in the hearts from R405W-desmin knock-in mice of both genotypes. Moreover, whereas heterozygous knock-in mice have a normal life span, homozygous animals die at 3 months of age because of a smooth muscle-related gastrointestinal phenotype. CONCLUSIONS We demonstrate that R406W-desmin provokes its severe cardiotoxic potential by a novel pathomechanism, where the concurrent dual functional states of mutant desmin assembly complexes underlie the uncoupling of desmin filaments from intercalated discs and their structural disorganization.
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Affiliation(s)
- Harald Herrmann
- Institute of Neuropathology (H.H., D.S., M.S., R.S.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany.,Molecular Genetics, German Cancer Research Center, Heidelberg, Germany (H.H.)
| | - Eva Cabet
- Basic and Translational Myology, Unit of Functional and Adaptive Biology (E.C., P.V., A.F., A.L.), University of Paris, France
| | - Nicolas R Chevalier
- Laboratoire Matière et Systèmes Complexes (N.R.C.), University of Paris, France
| | - Julia Moosmann
- Department of Pediatric Cardiology (J.M., S.D.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Dorothea Schultheis
- Institute of Neuropathology (H.H., D.S., M.S., R.S.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Jan Haas
- Institute for Cardiomyopathies Heidelberg, Heart Center Heidelberg, University of Heidelberg, Germany (J.H., B.M.)
| | - Mirjam Schowalter
- Institute of Neuropathology (H.H., D.S., M.S., R.S.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Carolin Berwanger
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (C.B., C.S.C.)
| | - Veronika Weyerer
- Institute of Pathology (V.W., A.A.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Abbas Agaimy
- Institute of Pathology (V.W., A.A.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Benjamin Meder
- Institute for Cardiomyopathies Heidelberg, Heart Center Heidelberg, University of Heidelberg, Germany (J.H., B.M.).,Department of Genetics, Stanford University School of Medicine, CA (B.M.)
| | - Oliver J Müller
- Internal Medicine III, University Hospital Schleswig-Holstein and University of Kiel, and German Center for Cardiovascular Research, partner site Hamburg/Kiel/Lübeck, Kiel, Germany (O.J.M.)
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital Heidelberg, and German Center for Cardiovascular Research, partner site Heidelberg/Mannheim, Heidelberg, Germany (H.A.K.)
| | - Ursula Schlötzer-Schrehardt
- Department of Ophthalmology (U.S.-S.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Patrick Vicart
- Basic and Translational Myology, Unit of Functional and Adaptive Biology (E.C., P.V., A.F., A.L.), University of Paris, France
| | - Ana Ferreiro
- Basic and Translational Myology, Unit of Functional and Adaptive Biology (E.C., P.V., A.F., A.L.), University of Paris, France.,Reference Center for Neuromuscular Disorders, Pitié-Salpêtrière Hospital, Assistance publique-Hôpitaux de Paris, France (A.F.)
| | - Sven Dittrich
- Department of Pediatric Cardiology (J.M., S.D.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
| | - Christoph S Clemen
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany (C.B., C.S.C.).,Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, Medical Faculty, and Center for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, Germany(C.S.C.)
| | - Alain Lilienbaum
- Basic and Translational Myology, Unit of Functional and Adaptive Biology (E.C., P.V., A.F., A.L.), University of Paris, France
| | - Rolf Schröder
- Institute of Neuropathology (H.H., D.S., M.S., R.S.), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Germany
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9
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AAV-mediated cardiac gene transfer of wild-type desmin in mouse models for recessive desminopathies. Gene Ther 2020; 27:516-524. [PMID: 32322014 PMCID: PMC7674151 DOI: 10.1038/s41434-020-0147-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 03/25/2020] [Accepted: 03/30/2020] [Indexed: 11/23/2022]
Abstract
Mutations in the human desmin gene cause autosomal-dominant and recessive cardiomyopathies and myopathies with marked phenotypic variability. Here, we investigated the effects of adeno-associated virus (AAV)-mediated cardiac wild-type desmin expression in homozygous desmin knockout (DKO) and homozygous R349P desmin knockin (DKI) mice. These mice serve as disease models for two subforms of autosomal-recessive desminopathies, the former for the one with a complete lack of desmin protein and the latter for the one with solely mutant desmin protein expression in conjunction with protein aggregation pathology in striated muscle. Two-month-old mice were injected with either a single dose of 5 × 1012 AAV9-hTNT2-mDes (AAV-Des) vector genomes or NaCl as control. One week after injection, mice were subjected to a forced swimming exercise protocol for 4 weeks. Cardiac function was monitored over a period of 15 month after injection and before the mice were sacrificed for biochemical and morphological analysis. AAV-mediated cardiac expression of wild-type desmin in both the homozygous DKO and DKI backgrounds reached levels seen in wild-type mice. Notably, AAV-Des treated DKO mice showed a regular subcellular distribution of desmin as well as a normalization of functional and morphological cardiac parameters. Treated DKI mice, however, showed an aberrant subcellular localization of desmin, unchanged functional cardiac parameters, and a trend toward an increased cardiac fibrosis. In conclusion, the effect of a high-dose AAV9-based desmin gene therapy is highly beneficial for the heart in DKO animals, but not in DKI mice.
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10
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Recessive DES cardio/myopathy without myofibrillar aggregates: intronic splice variant silences one allele leaving only missense L190P-desmin. Eur J Hum Genet 2019; 27:1267-1273. [PMID: 31024060 DOI: 10.1038/s41431-019-0393-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/04/2019] [Accepted: 03/19/2019] [Indexed: 01/08/2023] Open
Abstract
We establish autosomal recessive DES variants p.(Leu190Pro) and a deep intronic splice variant causing inclusion of a frameshift-inducing artificial exon/intronic fragment, as the likely cause of myopathy with cardiac involvement in female siblings. Both sisters presented in their twenties with slowly progressive limb girdle weakness, severe systolic dysfunction, and progressive, severe respiratory weakness. Desmin is an intermediate filament protein typically associated with autosomal dominant myofibrillar myopathy with cardiac involvement. However a few rare cases of autosomal recessive desminopathy are reported. In this family, a paternal missense p.(Leu190Pro) variant was viewed unlikely to be causative of autosomal dominant desminopathy, as the father and brothers carrying this variant were clinically unaffected. Clinical fit with a DES-related myopathy encouraged closer scrutiny of all DES variants, identifying a maternal deep intronic variant within intron-7, predicted to create a cryptic splice site, which segregated with disease. RNA sequencing and studies of muscle cDNA confirmed the deep intronic variant caused aberrant splicing of an artificial exon/intronic fragment into maternal DES mRNA transcripts, encoding a premature termination codon, and potently activating nonsense-mediate decay (92% paternal DES transcripts, 8% maternal). Western blot showed 60-75% reduction in desmin levels, likely comprised only of missense p.(Leu190Pro) desmin. Biopsy showed fibre size variation with increased central nuclei. Electron microscopy showed extensive myofibrillar disarray, duplication of the basal lamina, but no inclusions or aggregates. This study expands the phenotypic spectrum of recessive DES cardio/myopathy, and emphasizes the continuing importance of muscle biopsy for functional genomics pursuit of 'tricky' variants in neuromuscular conditions.
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Winter L, Unger A, Berwanger C, Spörrer M, Türk M, Chevessier F, Strucksberg KH, Schlötzer-Schrehardt U, Wittig I, Goldmann WH, Marcus K, Linke WA, Clemen CS, Schröder R. Imbalances in protein homeostasis caused by mutant desmin. Neuropathol Appl Neurobiol 2018; 45:476-494. [PMID: 30179276 DOI: 10.1111/nan.12516] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/17/2018] [Indexed: 12/19/2022]
Abstract
AIMS We investigated newly generated immortalized heterozygous and homozygous R349P desmin knock-in myoblasts in conjunction with the corresponding desminopathy mice as models for desminopathies to analyse major protein quality control processes in response to the presence of R349P mutant desmin. METHODS We used hetero- and homozygous R349P desmin knock-in mice for analyses and for crossbreeding with p53 knock-out mice to generate immortalized R349P desmin knock-in skeletal muscle myoblasts and myotubes. Skeletal muscle sections and cultured muscle cells were investigated by indirect immunofluorescence microscopy, proteasomal activity measurements and immunoblotting addressing autophagy rate, chaperone-assisted selective autophagy and heat shock protein levels. Muscle sections were further analysed by transmission and immunogold electron microscopy. RESULTS We demonstrate that mutant desmin (i) increases proteasomal activity, (ii) stimulates macroautophagy, (iii) dysregulates the chaperone assisted selective autophagy and (iv) elevates the protein levels of αB-crystallin and Hsp27. Both αB-crystallin and Hsp27 as well as Hsp90 displayed translocation patterns from Z-discs as well as Z-I junctions, respectively, to the level of sarcomeric I-bands in dominant and recessive desminopathies. CONCLUSIONS Our findings demonstrate that the presence of R349P mutant desmin causes a general imbalance in skeletal muscle protein homeostasis via aberrant activity of all major protein quality control systems. The augmented activity of these systems and the subcellular shift of essential heat shock proteins may deleteriously contribute to the previously observed increased turnover of desmin itself and desmin-binding partners, which triggers progressive dysfunction of the extrasarcomeric cytoskeleton and the myofibrillar apparatus in the course of the development of desminopathies.
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Affiliation(s)
- L Winter
- Institute of Neuropathology, University Hospital Erlangen, Erlangen, Germany.,Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - A Unger
- Department of Cardiovascular Physiology, Ruhr-University Bochum, Bochum, Germany.,Institute for Genetics of Heart Diseases, University Hospital Münster, Münster, Germany
| | - C Berwanger
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.,Center for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany
| | - M Spörrer
- Center for Medical Physics and Technology, Biophysics Group, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - M Türk
- Department of Neurology, University Hospital Erlangen, Erlangen, Germany
| | - F Chevessier
- Institute of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - K-H Strucksberg
- Center for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany
| | | | - I Wittig
- Functional Proteomics, SFB815 Core Unit, Medical School, Goethe University, Frankfurt, Germany
| | - W H Goldmann
- Center for Medical Physics and Technology, Biophysics Group, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - K Marcus
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - W A Linke
- Department of Cardiovascular Physiology, Ruhr-University Bochum, Bochum, Germany.,Institute of Physiology II, University of Münster, Münster, Germany
| | - C S Clemen
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.,Center for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany
| | - R Schröder
- Institute of Neuropathology, University Hospital Erlangen, Erlangen, Germany
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12
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Brodehl A, Gaertner-Rommel A, Milting H. Molecular insights into cardiomyopathies associated with desmin (DES) mutations. Biophys Rev 2018; 10:983-1006. [PMID: 29926427 DOI: 10.1007/s12551-018-0429-0] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 05/22/2018] [Indexed: 12/15/2022] Open
Abstract
Increasing usage of next-generation sequencing techniques pushed during the last decade cardiogenetic diagnostics leading to the identification of a huge number of genetic variants in about 170 genes associated with cardiomyopathies, channelopathies, or syndromes with cardiac involvement. Because of the biochemical and cellular complexity, it is challenging to understand the clinical meaning or even the relevant pathomechanisms of the majority of genetic sequence variants. However, detailed knowledge about the associated molecular pathomechanism is essential for the development of efficient therapeutic strategies in future and genetic counseling. Mutations in DES, encoding the muscle-specific intermediate filament protein desmin, have been identified in different kinds of cardiac and skeletal myopathies. Here, we review the functions of desmin in health and disease with a focus on cardiomyopathies. In addition, we will summarize the genetic and clinical literature about DES mutations and will explain relevant cell and animal models. Moreover, we discuss upcoming perspectives and consequences of novel experimental approaches like genome editing technology, which might open a novel research field contributing to the development of efficient and mutation-specific treatment options.
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Affiliation(s)
- Andreas Brodehl
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development, Heart and Diabetes Centre NRW, Ruhr-University Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany.
| | - Anna Gaertner-Rommel
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development, Heart and Diabetes Centre NRW, Ruhr-University Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development, Heart and Diabetes Centre NRW, Ruhr-University Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany.
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13
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Liewluck T, Milone M. Untangling the complexity of limb-girdle muscular dystrophies. Muscle Nerve 2018; 58:167-177. [PMID: 29350766 DOI: 10.1002/mus.26077] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2018] [Indexed: 12/16/2022]
Abstract
The limb-girdle muscular dystrophies (LGMDs) are a group of genetically heterogeneous, autosomal inherited muscular dystrophies with a childhood to adult onset, manifesting with hip- and shoulder-girdle muscle weakness. When the term LGMD was first conceptualized in 1954, it was thought to be a single entity. Currently, there are 8 autosomal dominant (LGMD1A-1H) and 26 autosomal recessive (LGMD2A-2Z) variants according to the Online Mendelian Inheritance in Man database. In addition, there are other genetically identified muscular dystrophies with an LGMD phenotype not yet classified as LGMD. This highlights the entanglement of LGMDs, which represents an area in continuous expansion. Herein we aim to simplify the complexity of LGMDs by subgrouping them on the basis of the underlying defective protein and impaired function. Muscle Nerve 58: 167-177, 2018.
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Affiliation(s)
- Teerin Liewluck
- Department of Neurology, Mayo Clinic, 200 First Street SW Rochester, Minnesota, 55905, USA
| | - Margherita Milone
- Department of Neurology, Mayo Clinic, 200 First Street SW Rochester, Minnesota, 55905, USA
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14
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Early signs of architectural and biomechanical failure in isolated myofibers and immortalized myoblasts from desmin-mutant knock-in mice. Sci Rep 2017; 7:1391. [PMID: 28469177 PMCID: PMC5431221 DOI: 10.1038/s41598-017-01485-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/29/2017] [Indexed: 01/25/2023] Open
Abstract
In striated muscle, desmin intermediate filaments interlink the contractile myofibrillar apparatus with mitochondria, nuclei, and the sarcolemma. The desmin network’s pivotal role in myocytes is evident since mutations in the human desmin gene cause severe myopathies and cardiomyopathies. Here, we investigated skeletal muscle pathology in myofibers and myofibrils isolated from young hetero- and homozygous R349P desmin knock-in mice, which carry the orthologue of the most frequent human desmin missense mutation R350P. We demonstrate that mutant desmin alters myofibrillar cytoarchitecture, markedly disrupts the lateral sarcomere lattice and distorts myofibrillar angular axial orientation. Biomechanical assessment revealed a high predisposition to stretch-induced damage in fiber bundles of R349P mice. Notably, Ca2+-sensitivity and passive myofibrillar tension were decreased in heterozygous fiber bundles, but increased in homozygous fiber bundles compared to wildtype mice. In a parallel approach, we generated and subsequently subjected immortalized heterozygous R349P desmin knock-in myoblasts to magnetic tweezer experiments that revealed a significantly increased sarcolemmal lateral stiffness. Our data suggest that mutated desmin already markedly impedes myocyte structure and function at pre-symptomatic stages of myofibrillar myopathies.
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15
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Genetic basis of dilated cardiomyopathy. Int J Cardiol 2016; 224:461-472. [PMID: 27736720 DOI: 10.1016/j.ijcard.2016.09.068] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/15/2016] [Accepted: 09/17/2016] [Indexed: 01/19/2023]
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16
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Mutant desmin substantially perturbs mitochondrial morphology, function and maintenance in skeletal muscle tissue. Acta Neuropathol 2016; 132:453-73. [PMID: 27393313 PMCID: PMC4992032 DOI: 10.1007/s00401-016-1592-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 06/23/2016] [Accepted: 06/24/2016] [Indexed: 12/18/2022]
Abstract
Secondary mitochondrial dysfunction is a feature in a wide variety of human protein aggregate diseases caused by mutations in different proteins, both in the central nervous system and in striated muscle. The functional relationship between the expression of a mutated protein and mitochondrial dysfunction is largely unknown. In particular, the mechanism how this dysfunction drives the disease process is still elusive. To address this issue for protein aggregate myopathies, we performed a comprehensive, multi-level analysis of mitochondrial pathology in skeletal muscles of human patients with mutations in the intermediate filament protein desmin and in muscles of hetero- and homozygous knock-in mice carrying the R349P desmin mutation. We demonstrate that the expression of mutant desmin causes disruption of the extrasarcomeric desmin cytoskeleton and extensive mitochondrial abnormalities regarding subcellular distribution, number and shape. At the molecular level, we uncovered changes in the abundancy and assembly of the respiratory chain complexes and supercomplexes. In addition, we revealed a marked reduction of mtDNA- and nuclear DNA-encoded mitochondrial proteins in parallel with large-scale deletions in mtDNA and reduced mtDNA copy numbers. Hence, our data demonstrate that the expression of mutant desmin causes multi-level damage of mitochondria already in early stages of desminopathies.
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17
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Jackson S, Schaefer J, Meinhardt M, Reichmann H. Mitochondrial abnormalities in the myofibrillar myopathies. Eur J Neurol 2015. [DOI: 10.1111/ene.12814] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- S. Jackson
- Department of Neurology; Technische Universität Dresden; Dresden Germany
| | - J. Schaefer
- Department of Neurology; Technische Universität Dresden; Dresden Germany
| | - M. Meinhardt
- Department of Pathology; Technische Universität Dresden; Dresden Germany
| | - H. Reichmann
- Department of Neurology; Technische Universität Dresden; Dresden Germany
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18
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Semmler AL, Sacconi S, Bach JE, Liebe C, Bürmann J, Kley RA, Ferbert A, Anderheiden R, Van den Bergh P, Martin JJ, De Jonghe P, Neuen-Jacob E, Müller O, Deschauer M, Bergmann M, Schröder JM, Vorgerd M, Schulz JB, Weis J, Kress W, Claeys KG. Unusual multisystemic involvement and a novel BAG3 mutation revealed by NGS screening in a large cohort of myofibrillar myopathies. Orphanet J Rare Dis 2014; 9:121. [PMID: 25208129 PMCID: PMC4347565 DOI: 10.1186/s13023-014-0121-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 07/21/2014] [Indexed: 12/14/2022] Open
Abstract
Background Myofibrillar myopathies (MFM) are a group of phenotypically and genetically heterogeneous neuromuscular disorders, which are characterized by protein aggregations in muscle fibres and can be associated with multisystemic involvement. Methods We screened a large cohort of 38 index patients with MFM for mutations in the nine thus far known causative genes using Sanger and next generation sequencing (NGS). We studied the clinical and histopathological characteristics in 38 index patients and five additional relatives (n = 43) and particularly focused on the associated multisystemic symptoms. Results We identified 14 heterozygous mutations (diagnostic yield of 37%), among them the novel p.Pro209Gln mutation in the BAG3 gene, which was associated with onset in adulthood, a mild phenotype and an axonal sensorimotor polyneuropathy, in the absence of giant axons at the nerve biopsy. We revealed several novel clinical phenotypes and unusual multisystemic presentations with previously described mutations: hearing impairment with a FLNC mutation, dysphonia with a mutation in DES and the first patient with a FLNC mutation presenting respiratory insufficiency as the initial symptom. Moreover, we described for the first time respiratory insufficiency occurring in a patient with the p.Gly154Ser mutation in CRYAB. Interestingly, we detected a polyneuropathy in 28% of the MFM patients, including a BAG3 and a MYOT case, and hearing impairment in 13%, including one patient with a FLNC mutation and two with mutations in the DES gene. In four index patients with a mutation in one of the MFM genes, typical histological findings were only identified at the ultrastructural level (29%). Conclusions We conclude that extraskeletal symptoms frequently occur in MFM, particularly cardiac and respiratory involvement, polyneuropathy and/or deafness. BAG3 mutations should be considered even in cases with a mild phenotype or an adult onset. We identified a genetic defect in one of the known genes in less than half of the MFM patients, indicating that more causative genes are still to be found. Next generation sequencing techniques should be helpful in achieving this aim.
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Affiliation(s)
- Anna-Lena Semmler
- Department of Neurology, RWTH Aachen University, Aachen, Germany. .,Institute of Neuropathology, RWTH Aachen University, Aachen, Germany.
| | - Sabrina Sacconi
- Centre de Référence des Maladies Neuromusculaires, Nice Hospital and UMR CNRS6543, Nice University, Nice, France.
| | - J Elisa Bach
- Department of Human Genetics, University of Würzburg, Würzburg, Germany.
| | - Claus Liebe
- Department of Neurology, RWTH Aachen University, Aachen, Germany. .,Institute of Neuropathology, RWTH Aachen University, Aachen, Germany.
| | - Jan Bürmann
- Department of Neurology, Saarland University, Homburg/Saar, Germany.
| | - Rudolf A Kley
- Department of Neurology, Neuromuscular Center Ruhrgebiet, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
| | | | | | - Peter Van den Bergh
- Department of Neurology, Neuromuscular Reference Center, University Hospital Saint-Luc, Brussel, Belgium.
| | | | - Peter De Jonghe
- Institute Born-Bunge, University of Antwerpen, Antwerpen, Belgium. .,Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerpen, Antwerpen, Belgium. .,Department of Neurology, University Hospital of Antwerpen, Antwerpen, Belgium.
| | - Eva Neuen-Jacob
- Institute of Neuropathology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
| | - Oliver Müller
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany. .,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg, Heidelberg, Germany.
| | - Marcus Deschauer
- Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle, Germany.
| | - Markus Bergmann
- Institute of Neuropathology, Klinikum Bremen-Mitte, Bremen, Germany.
| | | | - Matthias Vorgerd
- Department of Neurology, Neuromuscular Center Ruhrgebiet, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
| | - Jörg B Schulz
- Department of Neurology, RWTH Aachen University, Aachen, Germany. .,JARA - Translational Brain Medicine, Jülich and Aachen, Germany.
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University, Aachen, Germany. .,JARA - Translational Brain Medicine, Jülich and Aachen, Germany.
| | - Wolfram Kress
- Department of Human Genetics, University of Würzburg, Würzburg, Germany.
| | - Kristl G Claeys
- Department of Neurology, RWTH Aachen University, Aachen, Germany. .,Institute of Neuropathology, RWTH Aachen University, Aachen, Germany. .,JARA - Translational Brain Medicine, Jülich and Aachen, Germany.
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19
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Wilson K, Lucchesi PA. Myofilament dysfunction as an emerging mechanism of volume overload heart failure. Pflugers Arch 2014; 466:1065-77. [PMID: 24488008 DOI: 10.1007/s00424-014-1455-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 01/17/2014] [Accepted: 01/19/2014] [Indexed: 11/28/2022]
Abstract
Two main hemodynamic overload mechanisms [i.e., volume and pressure overload (VO and PO, respectively] result in heart failure (HF), and these two mechanisms have divergent pathologic alterations and different pathophysiological mechanisms. Extensive evidence from animal models and human studies of PO demonstrate a clear association with alterations in Ca(2+) homeostasis. By contrast, emerging evidence from animal models and patients with regurgitant valve disease and dilated cardiomyopathy point toward a more prominent role of myofilament dysfunction. With respect to VO HF, key features of excitation-contraction coupling defects, myofilament dysfunction, and extracellular matrix composition will be discussed.
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Affiliation(s)
- Kristin Wilson
- Center for Cardiovascular and Pulmonary Research and The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
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20
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Brodehl A, Dieding M, Klauke B, Dec E, Madaan S, Huang T, Gargus J, Fatima A, Saric T, Cakar H, Walhorn V, Tönsing K, Skrzipczyk T, Cebulla R, Gerdes D, Schulz U, Gummert J, Svendsen JH, Olesen MS, Anselmetti D, Christensen AH, Kimonis V, Milting H. The novel desmin mutant p.A120D impairs filament formation, prevents intercalated disk localization, and causes sudden cardiac death. ACTA ACUST UNITED AC 2013; 6:615-23. [PMID: 24200904 DOI: 10.1161/circgenetics.113.000103] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND The intermediate filament protein desmin is encoded by the gene DES and contributes to the mechanical stabilization of the striated muscle sarcomere and cell contacts within the cardiac intercalated disk. DES mutations cause severe skeletal and cardiac muscle diseases with heterogeneous phenotypes. Recently, DES mutations were also found in patients with arrhythmogenic right ventricular cardiomyopathy. Currently, the cellular and molecular pathomechanisms of the DES mutations leading to this disease are not exactly known. METHODS AND RESULTS We identified the 2 novel variants DES-p.A120D (c.359C>A) and DES-p.H326R (c.977A>G), which were characterized by cell culture experiments and atomic force microscopy. Family analysis indicated a broad spectrum of cardiomyopathies with a striking frequency of arrhythmias and sudden cardiac deaths. The in vitro experiments of desmin-p.A120D reveal a severe intrinsic filament formation defect causing cytoplasmic aggregates in cell lines and of the isolated recombinant protein. Model variants of codon 120 indicated that ionic interactions contribute to this filament formation defect. Ex vivo analysis of ventricular tissue slices revealed a loss of desmin staining within the intercalated disk and severe cytoplasmic aggregate formation, whereas z-band localization was not affected. The functional experiments of desmin-p.H326R did not demonstrate any differences from wild type. CONCLUSIONS Because of the functional in vivo and in vitro characterization, DES-p.A120D has to be regarded as a pathogenic mutation and DES-p.H326R as a rare variant with unknown significance. Presumably, the loss of the desmin-p. A120D filament localization at the intercalated disk explains its clinical arrhythmogenic potential.
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