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Oswald SL, Steinbrücker K, Achleitner MT, Göschl E, Bittner RE, Schmidt WM, Tiefenthaler E, Hammerl E, Eisl A, Mayr D, Mayr JA, Wortmann SB. Treatment of Mitochondrial Phenylalanyl-tRNa-Synthetase Deficiency (FARS2) with Oral Phenylalanine. Neuropediatrics 2023; 54:351-355. [PMID: 36603837 DOI: 10.1055/a-2008-4230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE By loading transfer RNAs with their cognate amino acids, aminoacyl-tRNA synthetases (ARS) are essential for protein translation. Both cytosolic ARS1-deficiencies and mitochondrial ARS2 deficiencies can cause severe diseases. Amino acid supplementation has shown to positively influence the clinical course of four individuals with cytosolic ARS1 deficiencies. We hypothesize that this intervention could also benefit individuals with mitochondrial ARS2 deficiencies. METHODS This study was designed as a N-of-1 trial. Daily oral L-phenylalanine supplementation was used in a 3-year-old girl with FARS2 deficiency. A period without supplementation was implemented to discriminate the effects of treatment from age-related developments and continuing physiotherapy. Treatment effects were measured through a physiotherapeutic testing battery, including movement assessment battery for children, dynamic gait index, gross motor function measure 66, and quality of life questionnaires. RESULTS The individual showed clear improvement in all areas tested, especially in gross motor skills, movement abilities, and postural stability. In the period without supplementation, she lost newly acquired motor skills but regained these upon restarting supplementation. No adverse effects and good tolerance of treatment were observed. INTERPRETATION AND CONCLUSION Our positive results encourage further studies both on L-phenylalanine for other individuals with FARS2 deficiency and the exploration of this treatment rationale for other ARS2 deficiencies. Additionally, treatment costs were relatively low at 1.10 €/day.
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Affiliation(s)
- Susanne L Oswald
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
| | - Katja Steinbrücker
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
| | - Melanie T Achleitner
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
| | | | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Elke Tiefenthaler
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
| | - Emma Hammerl
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
| | - Anna Eisl
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
| | - Doris Mayr
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
| | - Johannes A Mayr
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
| | - Saskia B Wortmann
- University Children's Hospital, Paracelsus Medical University (PMU) Salzburg, Salzburg, Austria
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
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2
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Dorninger F, Kiss A, Rothauer P, Stiglbauer-Tscholakoff A, Kummer S, Fallatah W, Perera-Gonzalez M, Hamza O, König T, Bober MB, Cavallé-Garrido T, Braverman NE, Forss-Petter S, Pifl C, Bauer J, Bittner RE, Helbich TH, Podesser BK, Todt H, Berger J. Overlapping and Distinct Features of Cardiac Pathology in Inherited Human and Murine Ether Lipid Deficiency. Int J Mol Sci 2023; 24:1884. [PMID: 36768204 PMCID: PMC9914995 DOI: 10.3390/ijms24031884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 01/21/2023] Open
Abstract
Inherited deficiency in ether lipids, a subgroup of glycerophospholipids with unique biochemical and biophysical properties, evokes severe symptoms in humans resulting in a multi-organ syndrome. Mouse models with defects in ether lipid biosynthesis have widely been used to understand the pathophysiology of human disease and to study the roles of ether lipids in various cell types and tissues. However, little is known about the function of these lipids in cardiac tissue. Previous studies included case reports of cardiac defects in ether-lipid-deficient patients, but a systematic analysis of the impact of ether lipid deficiency on the mammalian heart is still missing. Here, we utilize a mouse model of complete ether lipid deficiency (Gnpat KO) to accomplish this task. Similar to a subgroup of human patients with rhizomelic chondrodysplasia punctata (RCDP), a fraction of Gnpat KO fetuses present with defects in ventricular septation, presumably evoked by a developmental delay. We did not detect any signs of cardiomyopathy but identified increased left ventricular end-systolic and end-diastolic pressure in middle-aged ether-lipid-deficient mice. By comprehensive electrocardiographic characterization, we consistently found reduced ventricular conduction velocity, as indicated by a prolonged QRS complex, as well as increased QRS and QT dispersion in the Gnpat KO group. Furthermore, a shift of the Wenckebach point to longer cycle lengths indicated depressed atrioventricular nodal function. To complement our findings in mice, we analyzed medical records and performed electrocardiography in ether-lipid-deficient human patients, which, in contrast to the murine phenotype, indicated a trend towards shortened QT intervals. Taken together, our findings demonstrate that the cardiac phenotype upon ether lipid deficiency is highly heterogeneous, and although the manifestations in the mouse model only partially match the abnormalities in human patients, the results add to our understanding of the physiological role of ether lipids and emphasize their importance for proper cardiac development and function.
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Affiliation(s)
- Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Attila Kiss
- Center for Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Peter Rothauer
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Währingerstrasse 13a, 1090 Vienna, Austria
| | - Alexander Stiglbauer-Tscholakoff
- Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Structural Preclinical Imaging, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Stefan Kummer
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Straße 13, 1090 Vienna, Austria
| | - Wedad Fallatah
- Department of Genetic Medicine, King AbdulAziz University, Jeddah 21589, Saudi Arabia
- Department of Human Genetics and Pediatrics, Montreal Children’s Hospital, McGill University, 1001 Décarie Blvd, Montreal, QC H4A 3J1, Canada
| | - Mireia Perera-Gonzalez
- Center for Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Ouafa Hamza
- Center for Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Theresa König
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Michael B. Bober
- Skeletal Dysplasia Program, Nemours Children’s Hospital, 1600 Rockland Road, Wilmington, DE 19803, USA
| | - Tiscar Cavallé-Garrido
- Department of Pediatrics, Division of Cardiology, Montreal Children’s Hospital, McGill University, 1001 Décarie Blvd, Montreal, QC H4A 3J1, Canada
| | - Nancy E. Braverman
- Department of Human Genetics and Pediatrics, Montreal Children’s Hospital, McGill University, 1001 Décarie Blvd, Montreal, QC H4A 3J1, Canada
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Christian Pifl
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Jan Bauer
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Reginald E. Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Straße 13, 1090 Vienna, Austria
| | - Thomas H. Helbich
- Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Structural Preclinical Imaging, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Bruno K. Podesser
- Center for Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Hannes Todt
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Währingerstrasse 13a, 1090 Vienna, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
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3
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Winter L, Kustermann M, Ernhofer B, Höger H, Bittner RE, Schmidt WM. Proteins implicated in muscular dystrophy and cancer are functional constituents of the centrosome. Life Sci Alliance 2022; 5:5/11/e202201367. [PMID: 35790299 PMCID: PMC9259872 DOI: 10.26508/lsa.202201367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 12/02/2022] Open
Abstract
This study demonstrates that the muscular dystrophy-associated proteins dystrophin, utrophin, dysferlin, and calpain-3 localize to the centrosome and that their absence leads to excess centrosomes, compromised nuclear morphology, impaired centrosome orientation, and defective microtubule nucleation. Aberrant expression of dystrophin, utrophin, dysferlin, or calpain-3 was originally identified in muscular dystrophies (MDs). Increasing evidence now indicates that these proteins might act as tumor suppressors in myogenic and non-myogenic cancers. As DNA damage and somatic aneuploidy, hallmarks of cancer, are early pathological signs in MDs, we hypothesized that a common pathway might involve the centrosome. Here, we show that dystrophin, utrophin, dysferlin, and calpain-3 are functional constituents of the centrosome. In myoblasts, lack of any of these proteins caused excess centrosomes, centrosome misorientation, nuclear abnormalities, and impaired microtubule nucleation. In dystrophin double-mutants, these defects were significantly aggravated. Moreover, we demonstrate that also in non-myogenic cells, all four MD-related proteins localize to the centrosome, including the muscle-specific full-length dystrophin isoform. Therefore, MD-related proteins might share a convergent function at the centrosome in addition to their diverse, well-established muscle-specific functions. Thus, our findings support the notion that cancer-like centrosome-related defects underlie MDs and establish a novel concept linking MDs to cancer.
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Affiliation(s)
- Lilli Winter
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Monika Kustermann
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Büsra Ernhofer
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Harald Höger
- Division for Laboratory Animal Science and Genetics, Medical University of Vienna, Himberg, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
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4
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Bader I, Freilinger M, Landauer F, Waldmüller S, Mueller-Felber W, Rauscher C, Sperl W, Bittner RE, Schmidt WM, Mayr JA. A recurrent single-amino acid deletion (p.Glu500del) in the head domain of ß-cardiac myosin in two unrelated boys presenting with polyhydramnios, congenital axial stiffness and skeletal myopathy. Orphanet J Rare Dis 2022; 17:279. [PMID: 35854315 PMCID: PMC9295345 DOI: 10.1186/s13023-022-02421-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 06/30/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Alterations in the MYH7 gene can cause cardiac and skeletal myopathies. MYH7-related skeletal myopathies are extremely rare, and the vast majority of causal variants in the MYH7 gene are predicted to alter the rod domain of the of ß-cardiac myosin molecule, resulting in distal muscle weakness as the predominant manifestation. Here we describe two unrelated patients harboring an in-frame deletion in the MYH7 gene that is predicted to result in deletion of a single amino acid (p.Glu500del) in the head domain of ß-cardiac myosin. Both patients display an unusual skeletal myopathy phenotype with congenital axial stiffness and muscular hypertonus, but no cardiac involvement. RESULTS Clinical data, MRI results and histopathological data were collected retrospectively in two unrelated boys (9 and 3.5 years old). Exome sequencing uncovered the same 3-bp in-frame deletion in exon 15 (c.1498_1500delGAG) of the MYH7 gene of both patients, a mutation which deletes a highly conserved glutamate residue (p.Glu500del) in the relay loop of the head domain of the ß-cardiac myosin heavy chain. The mutation occurred de novo in one patient, whereas mosaicism was detected in blood of the father of the second patient. Both boys presented with an unusual phenotype of prenatal polyhydramnios, congenital axial stiffness and muscular hypertonus. In one patient the phenotype evolved into an axial/proximal skeletal myopathy without distal involvement or cardiomyopathy, whereas the other patient exhibited predominantly stiffness and respiratory involvement. We review and compare all patients described in the literature who possess a variant predicted to alter the p.Glu500 residue in the ß-cardiac myosin head domain, and we provide in-silico analyses of potential effects on polypeptide function. CONCLUSION The data presented here expand the phenotypic spectrum of mutations in the MYH7 gene and have implications for future diagnostics and therapeutic approaches.
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Affiliation(s)
- Ingrid Bader
- Clinical Genetics Unit, University Hospital, Salzburger Landeskliniken and Paracelsus Medical University Salzburg, 5020, Salzburg, Austria. .,University Children's Hospital, Salzburger Landeskliniken and Paracelsus Medical University Salzburg, 5020, Salzburg, Austria. .,Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstr. 7, 72076, Tübingen, Germany.
| | - M Freilinger
- Universitätsklinik Für Kinder- Und Jugendheilkunde, Medical University of Vienna, 1090, Vienna, Austria
| | - F Landauer
- University Clinic of Orthopaedic and Trauma Surgery, SALK and Paracelsus Medical University Salzburg, 5020, Salzburg, Austria
| | - S Waldmüller
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstr. 7, 72076, Tübingen, Germany
| | - W Mueller-Felber
- Dr. V. Hauner Children's Hospital, Ludwig-Maximilian University of Munich, Munich, Germany
| | - C Rauscher
- University Children's Hospital, Salzburger Landeskliniken and Paracelsus Medical University Salzburg, 5020, Salzburg, Austria
| | - W Sperl
- University Children's Hospital, Salzburger Landeskliniken and Paracelsus Medical University Salzburg, 5020, Salzburg, Austria
| | - R E Bittner
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, 1090, Vienna, Austria
| | - W M Schmidt
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, 1090, Vienna, Austria
| | - J A Mayr
- University Children's Hospital, Salzburger Landeskliniken and Paracelsus Medical University Salzburg, 5020, Salzburg, Austria
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5
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Siegert S, Schmidt WM, Pletschko T, Bittner RE, Gobara S, Freilinger M. Specific Cognitive Changes due to Hippocalcin Alterations? A Novel Familial Homozygous Hippocalcin Variant Associated with Inherited Dystonia and Altered Cognition. Neuropediatrics 2021; 52:377-382. [PMID: 33511595 DOI: 10.1055/s-0040-1722686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Recent research suggested an hippocalcin (HPCA)-related form of DYT2-like autosomal recessive dystonia. Two reports highlight a broad spectrum of the clinical phenotype. Here, we describe a novel HPCA gene variant in a pediatric patient and two affected relatives. METHODS Whole exome sequencing was applied after a thorough clinical and neurological examination of the index patient and her family members. Results of neuropsychological testing were analyzed. RESULTS Whole exome sequencing revealed a novel homozygous missense variant in the HPCA gene [c.182C>T p.(Ala61Val)] in our pediatric patient and the two affected family members. Clinically, the cases presented with dystonia, dysarthria, and jerky movements. We observed a particular cognitive profile with executive dysfunctions in our patient, which corresponds to the cognitive deficits that have been observed in the patients previously described. CONCLUSION We present a novel genetic variant of the HPCA gene associated with autosomal recessive dystonia in a child with childhood-onset dystonia supporting its clinical features. Furthermore, we propose specific HPCA-related cognitive changes in homozygous carriers, underlining the importance of undertaking a systematic assessment of cognition in HPCA-related dystonia.
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Affiliation(s)
- Sandy Siegert
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Austria
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Medical University of Vienna, Austria
| | - Thomas Pletschko
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Medical University of Vienna, Austria
| | - Sonja Gobara
- Ambulatorium Sonnenschein, Sozialpädiatrisches Zentrum, St. Pölten, Austria
| | - Michael Freilinger
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Austria
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6
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Amstetter D, Badt F, Rubi L, Bittner RE, Ebner J, Uhrin P, Hilber K, Koenig X, Todt H. The bradycardic agent ivabradine decreases conduction velocity in the AV node and in the ventricles in-vivo. Eur J Pharmacol 2021; 893:173818. [PMID: 33345856 DOI: 10.1016/j.ejphar.2020.173818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 12/02/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
Ivabradine blocks hyperpolarisation-activated cyclic nucleotide-gated (HCN) channels, thereby lowering the heart rate, an action that is used clinically for the treatment of heart failure and angina pectoris. We and others have shown previously that ivabradine, in addition to its HCN channel blocking activity, also inhibits voltage-gated Na channels in vitro at concentrations that may be clinically relevant. Such action may reduce conduction velocity in cardiac atria and ventricles. Here, we explore the effect of administration of ivabradine on parameters of ventricular conduction and repolarization in the surface ECG of anesthetized mice. We found that 5 min after i.p. administration of 10 mg/kg ivabradine spontaneous heart rate had declined by ~13%, which is within the range observed in human clinical studies. At the same time a significant increase in QRS duration by ~18% was observed, suggesting a reduction in ventricular conduction velocity. During transesophageal pacing at heart rates between 100 and 220 beats/min there was no obvious rate-dependence of ivabradine-induced QRS prolongation. On the other hand, ivabradine produced substantial rate-dependent slowing of AV nodal conduction. We conclude that ivabradine prolongs conduction in the AV-node and in the ventricles in vivo.
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Affiliation(s)
- Daniel Amstetter
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Florian Badt
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Lena Rubi
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Janine Ebner
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Pavel Uhrin
- Department of Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology, Austria
| | - Karlheinz Hilber
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Xaver Koenig
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannes Todt
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria.
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7
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Gerwin L, Rossmanith S, Haupt C, Schultheiß J, Brinkmeier H, Bittner RE, Kröger S. Impaired muscle spindle function in murine models of muscular dystrophy. J Physiol 2020; 598:1591-1609. [PMID: 32003874 DOI: 10.1113/jp278563] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 01/24/2020] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Muscular dystrophy patients suffer from progressive degeneration of skeletal muscle fibres, sudden spontaneous falls, balance problems, as well as gait and posture abnormalities. Dystrophin- and dysferlin-deficient mice, models for different types of muscular dystrophy with different aetiology and molecular basis, were characterized to investigate if muscle spindle structure and function are impaired. The number and morphology of muscle spindles were unaltered in both dystrophic mouse lines but muscle spindle resting discharge and their responses to stretch were altered. In dystrophin-deficient muscle spindles, the expression of the paralogue utrophin was substantially upregulated, potentially compensating for the dystrophin deficiency. The results suggest that muscle spindles might contribute to the motor problems observed in patients with muscular dystrophy. ABSTRACT Muscular dystrophies comprise a heterogeneous group of hereditary diseases characterized by progressive degeneration of extrafusal muscle fibres as well as unstable gait and frequent falls. To investigate if muscle spindle function is impaired, we analysed their number, morphology and function in wildtype mice and in murine model systems for two distinct types of muscular dystrophy with very different disease aetiology, i.e. dystrophin- and dysferlin-deficient mice. The total number and the overall structure of muscle spindles in soleus muscles of both dystrophic mouse mutants appeared unchanged. Immunohistochemical analyses of wildtype muscle spindles revealed a concentration of dystrophin and β-dystroglycan in intrafusal fibres outside the region of contact with the sensory neuron. While utrophin was absent from the central part of intrafusal fibres of wildtype mice, it was substantially upregulated in dystrophin-deficient mice. Single-unit extracellular recordings of sensory afferents from muscle spindles of the extensor digitorum longus muscle revealed that muscle spindles from both dystrophic mouse strains have an increased resting discharge and a higher action potential firing rate during sinusoidal vibrations, particularly at low frequencies. The response to ramp-and-hold stretches appeared unaltered compared to the respective wildtype mice. We observed no exacerbated functional changes in dystrophin and dysferlin double mutant mice compared to the single mutant animals. These results show alterations in muscle spindle afferent responses in both dystrophic mouse lines, which might cause an increased muscle tone, and might contribute to the unstable gait and frequent falls observed in patients with muscular dystrophy.
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Affiliation(s)
- Laura Gerwin
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152, Planegg-Martinsried, Germany.,Institute for Stem Cell Research, German Research Center for Environmental Health, Helmholtz Centre Munich, Ingolstädter Landstraße 1, D-85764, Neuherberg, Germany
| | - Sarah Rossmanith
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152, Planegg-Martinsried, Germany
| | - Corinna Haupt
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152, Planegg-Martinsried, Germany
| | - Jürgen Schultheiß
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152, Planegg-Martinsried, Germany
| | - Heinrich Brinkmeier
- Institute for Pathophysiology, University Medicine Greifswald, Martin-Luther-Str. 6, 17489, Greifswald, Germany
| | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Waehringerstrasse 13, 1090, Vienna, Austria
| | - Stephan Kröger
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152, Planegg-Martinsried, Germany
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8
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Rahikkala E, Myllykoski M, Hinttala R, Vieira P, Nayebzadeh N, Weiss S, Plomp AS, Bittner RE, Kurki MI, Kuismin O, Lewis AM, Väisänen ML, Kokkonen H, Westermann J, Bernert G, Tuominen H, Palotie A, Aaltonen L, Yang Y, Potocki L, Moilanen J, van Koningsbruggen S, Wang X, Schmidt WM, Koivunen P, Uusimaa J. Biallelic loss-of-function P4HTM gene variants cause hypotonia, hypoventilation, intellectual disability, dysautonomia, epilepsy, and eye abnormalities (HIDEA syndrome). Genet Med 2019; 21:2355-2363. [PMID: 30940925 PMCID: PMC6774999 DOI: 10.1038/s41436-019-0503-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Accepted: 03/18/2019] [Indexed: 12/19/2022] Open
Abstract
PURPOSE A new syndrome with hypotonia, intellectual disability, and eye abnormalities (HIDEA) was previously described in a large consanguineous family. Linkage analysis identified the recessive disease locus, and genome sequencing yielded three candidate genes with potentially pathogenic biallelic variants: transketolase (TKT), transmembrane prolyl 4-hydroxylase (P4HTM), and ubiquitin specific peptidase 4 (USP4). However, the causative gene remained elusive. METHODS International collaboration and exome sequencing were used to identify new patients with HIDEA and biallelic, potentially pathogenic, P4HTM variants. Segregation analysis was performed using Sanger sequencing. P4H-TM wild-type and variant constructs without the transmembrane region were overexpressed in insect cells and analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot. RESULTS Five different homozygous or compound heterozygous pathogenic P4HTM gene variants were identified in six new and six previously published patients presenting with HIDEA. Hypoventilation, obstructive and central sleep apnea, and dysautonomia were identified as novel features associated with the phenotype. Characterization of three of the P4H-TM variants demonstrated yielding insoluble protein products and, thus, loss-of-function. CONCLUSIONS Biallelic loss-of-function P4HTM variants were shown to cause HIDEA syndrome. Our findings enable diagnosis of the condition, and highlight the importance of assessing the need for noninvasive ventilatory support in patients.
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Affiliation(s)
- Elisa Rahikkala
- PEDEGO Research Unit and Medical Research Centre Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland. .,Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland.
| | - Matti Myllykoski
- Biocenter Oulu, University of Oulu, Oulu, Finland.,Faculty of Biochemistry and Molecular Medicine, Oulu Centre for Cell-Matrix Research, University of Oulu, Oulu, Finland
| | - Reetta Hinttala
- PEDEGO Research Unit and Medical Research Centre Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Päivi Vieira
- PEDEGO Research Unit and Medical Research Centre Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Department of Children and Adolescents, Division of Paediatric Neurology, Oulu University Hospital, Oulu, Finland
| | - Naemeh Nayebzadeh
- PEDEGO Research Unit and Medical Research Centre Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Simone Weiss
- Kaiser Franz Josef Hospital with G.v. Preyer Children's Hospital, Department of Pediatrics, Vienna, Austria
| | - Astrid S Plomp
- Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Reginald E Bittner
- Neuromuscular Research Department, Medical University of Vienna, Centre for Anatomy and Cell Biology, Vienna, Austria
| | - Mitja I Kurki
- Psychiatric & Neurodevelopmental Genetics Unit, Massachusetts General Hospital, Boston, MA, USA.,The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Outi Kuismin
- PEDEGO Research Unit and Medical Research Centre Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland.,Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Andrea M Lewis
- Texas Children's Hospital, Houston, TX, USA.,Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Marja-Leena Väisänen
- Northern Finland Laboratory Centre NordLab and Medical Research Centre, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Hannaleena Kokkonen
- Northern Finland Laboratory Centre NordLab and Medical Research Centre, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Jonne Westermann
- Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Günther Bernert
- Kaiser Franz Josef Hospital with G.v. Preyer Children's Hospital, Department of Pediatrics, Vienna, Austria
| | - Hannu Tuominen
- Department of Pathology, Oulu University Hospital, Oulu, Finland
| | - Aarno Palotie
- Psychiatric & Neurodevelopmental Genetics Unit, Massachusetts General Hospital, Boston, MA, USA.,The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland.,Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Lauri Aaltonen
- Department of Medical Genetics, Genome-Scale Biology Research Program, University of Helsinki and Haartman Institute, Helsinki, Finland
| | - Yaping Yang
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Lorraine Potocki
- Texas Children's Hospital, Houston, TX, USA.,Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jukka Moilanen
- PEDEGO Research Unit and Medical Research Centre Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland
| | | | - Xia Wang
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Medical University of Vienna, Centre for Anatomy and Cell Biology, Vienna, Austria
| | - Peppi Koivunen
- Biocenter Oulu, University of Oulu, Oulu, Finland.,Faculty of Biochemistry and Molecular Medicine, Oulu Centre for Cell-Matrix Research, University of Oulu, Oulu, Finland
| | - Johanna Uusimaa
- PEDEGO Research Unit and Medical Research Centre Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland.,Department of Children and Adolescents, Division of Paediatric Neurology, Oulu University Hospital, Oulu, Finland
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9
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Stepien KM, Schmidt WM, Bittner RE, O'Toole O, McNamara B, Treacy EP. Long-term outcomes in a 25-year-old female affected with lipin-1 deficiency. JIMD Rep 2019; 46:4-10. [PMID: 31240148 PMCID: PMC6498837 DOI: 10.1002/jmd2.12016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 01/04/2019] [Indexed: 12/19/2022] Open
Abstract
Lipin-1 is a phosphatidic acid phosphohydrolase (EC 3.1.3.4) that catalyzes the dephosphorylation of phosphatidic acid to diacylglycerol and inorganic phosphate. Deficiency of this enzyme causes potentially fatal severe, recurrent episodes of rhabdomyolysis triggered by infection. The defect has only recently been recognized so little is known about the long-term outcome in adult patients with this disorder. We report the course and outcome of a 25-year-old female patient with lipin-1 deficiency after a recent episode of rhabdomyolysis requiring intensive care admission with a peak creatine kinase of 500 000 IU/L. One-year post discharge from intensive care, the patient has residual drop foot bilaterally consistent with bilateral common peroneal neuropathies in addition to a background residual distal myopathy.
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Affiliation(s)
- Karolina M. Stepien
- Mark Holland Metabolic Unit, Adult Inherited Metabolic DiseasesSalford Royal NHS Foundation TrustSalfordUnited Kingdom
| | - Wolfgang M. Schmidt
- Neuromuscular Research DepartmentCenter for Anatomy and Cell Biology, Medical University of ViennaViennaAustria
| | - Reginald E. Bittner
- Neuromuscular Research DepartmentCenter for Anatomy and Cell Biology, Medical University of ViennaViennaAustria
| | - Orna O'Toole
- Department of NeurologyMercy University HospitalCorkIreland
| | - Brian McNamara
- Department of Clinical NeurophysiologyCork University HospitalCorkIreland
| | - Eileen P. Treacy
- University College DublinDublinIreland
- Paediatrics DepartmentTrinity CollegeDublinIreland
- National Centre for Inherited Metabolic DiseasesThe Mater Misericordiae University HospitalDublinIreland
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10
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Schatz UA, Weiss S, Wenninger S, Schoser B, Muss WH, Bittner RE, Schmidt WM, Schossig AS, Rudnik-Schöneborn S, Baumann M. Evidence of mild founder LMOD3 mutations causing nemaline myopathy 10 in Germany and Austria. Neurology 2018; 91:e1690-e1694. [PMID: 30291184 DOI: 10.1212/wnl.0000000000006428] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/19/2018] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE To expand the clinical and genetic spectrum of nemaline myopathy 10 by a series of Austrian and German patients with a milder disease course and missense mutations in LMOD3. METHODS We characterized the clinical features and the genetic status of 4 unrelated adolescent or adult patients with nemaline myopathy. RESULTS The 4 patients showed a relatively mild disease course. They all have survived into adulthood, 3 of 4 have remained ambulatory, and all showed marked facial weakness. Muscle biopsy specimens gave evidence of nemaline bodies. All patients were unrelated but originated from Austria (Tyrol and Upper Austria) and Southern Germany (Bavaria). All patients carried the missense variant c.1648C>T, p.(Leu550Phe) in the LMOD3 gene, either on both alleles or in trans with another missense variant (c.1004A>G, p.Gln335Arg). Both variants were not reported previously. CONCLUSIONS In 2014, a severe form of congenital nemaline myopathy caused by disrupting mutations in LMOD3 was identified and denoted as NEM10. Unlike the previously reported patients, who had a severe clinical picture with a substantial risk of early death, our patients showed a relatively mild disease course. As the missense variant c.1648C>T is located further downstream compared to all previously published LMOD3 mutations, it might be associated with higher protein expression compared to the reported loss-of-function mutations. The apparent clusters of 2 mild mutations in Germany and Austria in 4 unrelated families may be explained by a founder effect.
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Affiliation(s)
- Ulrich A Schatz
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Simone Weiss
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Stephan Wenninger
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Benedikt Schoser
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Wolfgang H Muss
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Reginald E Bittner
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Wolfgang M Schmidt
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Anna S Schossig
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Sabine Rudnik-Schöneborn
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.)
| | - Matthias Baumann
- From the Department of Human Genetics (UA.S., AS.S., S.R.), Department of Pediatrics (M.B.), Medical University Innsbruck, Austria; Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria (S.W.); Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University Munich, Germany (St.W., B.S.); Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität Munich, Germany (UA.S., AS.S.); Institute of Pathology, SALK-LKH and PMU (Paracelsus Medical University) Salzburg, Austria (WH.M, retired); Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria (RE.B., WM.S.).
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11
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Baumann M, Steichen-Gersdorf E, Krabichler B, Petersen BS, Weber U, Schmidt WM, Zschocke J, Müller T, Bittner RE, Janecke AR. Homozygous SYNE1 mutation causes congenital onset of muscular weakness with distal arthrogryposis: a genotype-phenotype correlation. Eur J Hum Genet 2016; 25:262-266. [PMID: 27782104 DOI: 10.1038/ejhg.2016.144] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/07/2016] [Accepted: 09/20/2016] [Indexed: 01/15/2023] Open
Abstract
The exceptionally large SYNE1 (spectrin repeat-containing nuclear envelope protein 1) gene encodes different nesprin-1 isoforms, which are differentially expressed in striated muscle and in cerebellar and cerebral neurons. Nesprin-1 isoforms can function in cytoskeletal, nuclear, and vesicle anchoring. SYNE1 variants have been associated with a spectrum of neurological and neuromuscular disease. Homozygosity mapping combined with exome sequencing identified a disease-causing nonsense mutation in the ultimate exon of full-length SYNE1 transcript in an 8-year-old boy with distal arthrogryposis and muscular hypotonia. mRNA analysis showed that the mutant transcript is expressed at wild-type levels. The variant truncates nesprin-1 isoforms for the C-terminal KASH (Klarsicht-ANC-Syne homology) domain. This is the third family with recessive arthrogryposis caused by homozygous distal-truncating SYNE1 variants. There is a SYNE1 genotype-phenotype correlation emerging, with more proximal homozygous SYNE1 variants causing recessive cerebellar ataxia of variable onset (SCAR8; ARCA-1).
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Affiliation(s)
- Matthias Baumann
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Birgit Krabichler
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Britt-Sabina Petersen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Ulrike Weber
- Department of Pediatrics, Krankenhaus Dornbirn, Dornbirn, Austria
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Johannes Zschocke
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Müller
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Andreas R Janecke
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria.,Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
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12
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Auer J, Wallner M, Windpessl M, Schmidt WM, Bittner RE, Baradaran-Dilmaghani R, Berent R. Acute decompensated heart failure associated with a heteroplasmic 3243A > G mitochondrial DNA point mutation. Eur Heart J 2016; 37:1707. [PMID: 26941201 DOI: 10.1093/eurheartj/ehw074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Johann Auer
- Department of Cardiology and Intensive Care, St Josef Hospital Braunau, Ringstrasse 60, 5280 Braunau, Austria
| | - Manfred Wallner
- Department of Nephrology, Klinikum Wels-Grieskirchen, Wels, Austria
| | - Martin Windpessl
- Department of Nephrology, Klinikum Wels-Grieskirchen, Wels, Austria
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, Austria
| | | | - Robert Berent
- HerzReha Bad Ischl, Center of Cardiovascular Rehabilitation Bad Ischl, Bad Ischl, Austria
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13
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Schmidt WM, Rutledge SL, Schüle R, Mayerhofer B, Züchner S, Boltshauser E, Bittner RE. Disruptive SCYL1 Mutations Underlie a Syndrome Characterized by Recurrent Episodes of Liver Failure, Peripheral Neuropathy, Cerebellar Atrophy, and Ataxia. Am J Hum Genet 2015; 97:855-61. [PMID: 26581903 DOI: 10.1016/j.ajhg.2015.10.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 10/16/2015] [Indexed: 12/15/2022] Open
Abstract
Hereditary ataxias comprise a group of genetically heterogeneous disorders characterized by clinically variable cerebellar dysfunction and accompanied by involvement of other organ systems. The molecular underpinnings for many of these diseases are widely unknown. Previously, we discovered the disruption of Scyl1 as the molecular basis of the mouse mutant mdf, which is affected by neurogenic muscular atrophy, progressive gait ataxia with tremor, cerebellar vermis atrophy, and optic-nerve thinning. Here, we report on three human individuals, from two unrelated families, who presented with recurrent episodes of acute liver failure in early infancy and are affected by cerebellar vermis atrophy, ataxia, and peripheral neuropathy. By whole-exome sequencing, compound-heterozygous mutations within SCYL1 were identified in all affected individuals. We further show that in SCYL1-deficient human fibroblasts, the Golgi apparatus is massively enlarged, which is in line with the concept that SCYL1 regulates Golgi integrity. Thus, our findings define SCYL1 mutations as the genetic cause of a human hepatocerebellar neuropathy syndrome.
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Affiliation(s)
- Wolfgang M Schmidt
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - S Lane Rutledge
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Rebecca Schüle
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany; German Research Center for Neurodegenerative Diseases, University of Tübingen, 72076 Tübingen, Germany; Dr. John T. Macdonald Department of Human Genetics and John P. Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Benjamin Mayerhofer
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - Stephan Züchner
- Dr. John T. Macdonald Department of Human Genetics and John P. Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Eugen Boltshauser
- Division of Pediatric Neurology, University Children's Hospital, 8032 Zurich, Switzerland
| | - Reginald E Bittner
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, 1090 Vienna, Austria.
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14
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Pichler K, Scholl-Buergi S, Birnbacher R, Freilinger M, Straub S, Brunner J, Zschocke J, Bittner RE, Karall D. A novel therapeutic approach for LPIN1 mutation-associated rhabdomyolysis--The Austrian experience. Muscle Nerve 2015; 52:437-9. [PMID: 26111941 DOI: 10.1002/mus.24749] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2015] [Indexed: 11/07/2022]
Abstract
INTRODUCTION Lipin 1 gene (LPIN1) mutations lead to cellular energy deficiency and cause up to 50% of the rhabdomyolysis episodes seen in pediatric patients. These episodes are associated with poor prognosis, as treatment options have been limited. We propose a novel therapeutic strategy based on prevention and early treatment of catabolism. METHODS Five patients were diagnosed with LPIN1 mutations. They were instructed to maintain high caloric intake in situations possibly leading to catabolism such as viral infections or excessive physical activity. When an episode of rhabdomyolysis occurred, patients were treated with intravenous high-concentration glucose at first symptoms. RESULTS The therapeutic strategies described limited the number of rhabdomyolyis episodes, and the duration of episodes was reduced from 7-10 days, as reported in the literature, to 5 days. CONCLUSION In this small series, patients with LPIN1 mutations appear to have benefited from prevention and early treatment of catabolism.
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Affiliation(s)
- Karin Pichler
- Department of Pediatrics, Clinic for Pediatrics I, Medical University of Innsbruck, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Sabine Scholl-Buergi
- Department of Pediatrics, Clinic for Pediatrics I, Medical University of Innsbruck, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Robert Birnbacher
- Department of Pediatrics, General Hospital Villach, Villach, Austria
| | - Michael Freilinger
- Department of Pediatrics and Adolescent Medicine, Medical University Vienna, Vienna, Austria
| | - Simon Straub
- Department of Pediatrics, Clinic for Pediatrics I, Medical University of Innsbruck, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Jürgen Brunner
- Department of Pediatrics, Clinic for Pediatrics I, Medical University of Innsbruck, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Johannes Zschocke
- Institute of Human Genetics, Medical University of Innsbruck, Innbruck, Austria
| | - Reginald E Bittner
- Center for Anatomy and Cell Biology, Department of Applied Anatomy, Medical University of Vienna, Vienna, Austria
| | - Daniela Karall
- Department of Pediatrics, Clinic for Pediatrics I, Medical University of Innsbruck, Anichstrasse 35, A-6020, Innsbruck, Austria
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15
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Koenig X, Rubi L, Obermair GJ, Cervenka R, Dang XB, Lukacs P, Kummer S, Bittner RE, Kubista H, Todt H, Hilber K. Enhanced currents through L-type calcium channels in cardiomyocytes disturb the electrophysiology of the dystrophic heart. Am J Physiol Heart Circ Physiol 2013; 306:H564-H573. [PMID: 24337461 DOI: 10.1152/ajpheart.00441.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Duchenne muscular dystrophy (DMD), induced by mutations in the gene encoding for the cytoskeletal protein dystrophin, is an inherited disease characterized by progressive muscle weakness. Besides the relatively well characterized skeletal muscle degenerative processes, DMD is also associated with cardiac complications. These include cardiomyopathy development and cardiac arrhythmias. The current understanding of the pathomechanisms in the heart is very limited, but recent research indicates that dysfunctional ion channels in dystrophic cardiomyocytes play a role. The aim of the present study was to characterize abnormalities in L-type calcium channel function in adult dystrophic ventricular cardiomyocytes. By using the whole cell patch-clamp technique, the properties of currents through calcium channels in ventricular cardiomyocytes isolated from the hearts of normal and dystrophic adult mice were compared. Besides the commonly used dystrophin-deficient mdx mouse model for human DMD, we also used mdx-utr mice, which are both dystrophin- and utrophin-deficient. We found that calcium channel currents were significantly increased, and channel inactivation was reduced in dystrophic cardiomyocytes. Both effects enhance the calcium influx during an action potential (AP). Whereas the AP in dystrophic mouse cardiomyocytes was nearly normal, implementation of the enhanced dystrophic calcium conductance in a computer model of a human ventricular cardiomyocyte considerably prolonged the AP. Finally, the described dystrophic calcium channel abnormalities entailed alterations in the electrocardiograms of dystrophic mice. We conclude that gain of function in cardiac L-type calcium channels may disturb the electrophysiology of the dystrophic heart and thereby cause arrhythmias.
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Affiliation(s)
- Xaver Koenig
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Lena Rubi
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Gerald J Obermair
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Rene Cervenka
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Xuan B Dang
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Peter Lukacs
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Stefan Kummer
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Reginald E Bittner
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Helmut Kubista
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannes Todt
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Karlheinz Hilber
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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16
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Ritter M, Zotter S, Schmidt WM, Bittner RE, Deak GG, Pircher M, Sacu S, Hitzenberger CK, Schmidt-Erfurth UM. Characterization of Stargardt Disease Using Polarization-Sensitive Optical Coherence Tomography and Fundus Autofluorescence Imaging. ACTA ACUST UNITED AC 2013; 54:6416-25. [DOI: 10.1167/iovs.12-11550] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Markus Ritter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Stefan Zotter
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Wolfgang M. Schmidt
- Center of Anatomy and Cell Biology, Neuromuscular Research Department, Medical University of Vienna, Vienna, Austria
| | - Reginald E. Bittner
- Center of Anatomy and Cell Biology, Neuromuscular Research Department, Medical University of Vienna, Vienna, Austria
| | - Gabor G. Deak
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Stefan Sacu
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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17
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Koenig X, Dang XB, Rubi L, Mike ÁK, Lukács P, Cervenka R, Gawali VS, Todt H, Bittner RE, Hilber K. Impaired L-type Ca2+ channel function in the dystrophic heart. BMC Pharmacol Toxicol 2012. [PMCID: PMC3506300 DOI: 10.1186/2050-6511-13-s1-a41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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18
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Mohamed BA, Barakat AZ, Zimmermann WH, Bittner RE, Mühlfeld C, Hünlich M, Engel W, Maier LS, Adham IM. Targeted disruption of Hspa4 gene leads to cardiac hypertrophy and fibrosis. J Mol Cell Cardiol 2012; 53:459-68. [PMID: 22884543 DOI: 10.1016/j.yjmcc.2012.07.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 07/12/2012] [Accepted: 07/24/2012] [Indexed: 01/14/2023]
Abstract
Failure of molecular chaperones to direct the correct folding of newly synthesized proteins leads to the accumulation of misfolded proteins in cells. HSPA4 is a member of the heat shock protein 110 family (HSP110) that acts as a nucleotide exchange factor of HSP70 chaperones. We found that the expression of HSPA4 is upregulated in murine hearts subjected to pressure overload and in failing human hearts. To investigate the cardiac function of HSPA4, Hspa4 knockout (KO) mice were generated and exhibited cardiac hypertrophy and fibrosis. Hspa4 KO hearts were characterized by a significant increase in heart weight/body weight ratio, elevated expression of hypertrophic and fibrotic gene markers, and concentric hypertrophy with preserved contractile function. In response to pressure overload, cardiac hypertrophy and remodeling were further aggravated in the Hspa4 KO compared to wild type (WT) mice. Cardiac hypertrophy in Hspa4 KO hearts was associated with enhanced activation of gp130-STAT3, CaMKII, and calcineurin-NFAT signaling. Protein blot and immunofluorescent analyses showed a significant accumulation of polyubiquitinated proteins in cardiac cells of Hspa4 KO mice. These results suggest that the myocardial remodeling of Hspa4 KO mice is due to accumulation of misfolded proteins resulting from impaired chaperone activity. Further analyses revealed a significant increase in cross sectional area of cardiomyocytes, and in expression levels of hypertrophic markers in cultured neonatal Hspa4 KO cardiomyocytes suggesting that the hypertrophy of mutant mice was a result of primary defects in cardiomyocytes. Gene expression profile in hearts of 3.5-week-old mice revealed a differentially expressed gene sets related to ion channels, muscle-specific contractile proteins and stress response. Taken together, our in vivo data demonstrate that Hspa4 gene ablation results in cardiac hypertrophy and fibrosis, possibly, through its role in protein quality control mechanism.
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Affiliation(s)
- Belal A Mohamed
- Institute of Human Genetics, University of Göttingen, Germany
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19
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Koenig X, Dysek S, Kimbacher S, Mike AK, Cervenka R, Lukacs P, Nagl K, Dang XB, Todt H, Bittner RE, Hilber K. Voltage-gated ion channel dysfunction precedes cardiomyopathy development in the dystrophic heart. PLoS One 2011; 6:e20300. [PMID: 21677768 PMCID: PMC3100353 DOI: 10.1371/journal.pone.0020300] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 04/24/2011] [Indexed: 12/15/2022] Open
Abstract
Background Duchenne muscular dystrophy (DMD), caused by mutations in the dystrophin gene, is associated with severe cardiac complications including cardiomyopathy and cardiac arrhythmias. Recent research suggests that impaired voltage-gated ion channels in dystrophic cardiomyocytes accompany cardiac pathology. It is, however, unknown if the ion channel defects are primary effects of dystrophic gene mutations, or secondary effects of the developing cardiac pathology. Methodology/Principal Findings To address this question, we first investigated sodium channel impairments in cardiomyocytes derived from dystrophic neonatal mice prior to cardiomyopahty development, by using the whole cell patch clamp technique. Besides the most common model for DMD, the dystrophin-deficient mdx mouse, we also used mice additionally carrying an utrophin mutation. In neonatal cardiomyocytes, dystrophin-deficiency generated a 25% reduction in sodium current density. In addition, extra utrophin-deficiency significantly altered sodium channel gating parameters. Moreover, also calcium channel inactivation was considerably reduced in dystrophic neonatal cardiomyocytes, suggesting that ion channel abnormalities are universal primary effects of dystrophic gene mutations. To assess developmental changes, we also studied sodium channel impairments in cardiomyocytes derived from dystrophic adult mice, and compared them with the respective abnormalities in dystrophic neonatal cells. Here, we found a much stronger sodium current reduction in adult cardiomyocytes. The described sodium channel impairments slowed the upstroke of the action potential in adult cardiomyocytes, and only in dystrophic adult mice, the QRS interval of the electrocardiogram was prolonged. Conclusions/Significance Ion channel impairments precede pathology development in the dystrophic heart, and may thus be considered potential cardiomyopathy triggers.
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MESH Headings
- Action Potentials/physiology
- Animals
- Animals, Newborn
- Barium/metabolism
- Calcium Channels, L-Type/metabolism
- Cardiomyopathies/pathology
- Cardiomyopathies/physiopathology
- Cells, Cultured
- Dystrophin/genetics
- Electrocardiography
- Humans
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/physiopathology
- Mutation
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Patch-Clamp Techniques
- Sodium/metabolism
- Sodium Channels/metabolism
- Utrophin/deficiency
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Affiliation(s)
- Xaver Koenig
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Sandra Dysek
- Center for Anatomy and Cell Biology, Neuromuscular Research Department, Medical University of Vienna, Vienna, Austria
| | - Stefanie Kimbacher
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- Center for Anatomy and Cell Biology, Neuromuscular Research Department, Medical University of Vienna, Vienna, Austria
| | - Agnes K. Mike
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Rene Cervenka
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Peter Lukacs
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Katrin Nagl
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Xuan B. Dang
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannes Todt
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Reginald E. Bittner
- Center for Anatomy and Cell Biology, Neuromuscular Research Department, Medical University of Vienna, Vienna, Austria
| | - Karlheinz Hilber
- Center for Physiology and Pharmacology, Department of Neurophysiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- * E-mail:
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20
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Schmidt WM, Uddin MH, Dysek S, Moser-Thier K, Pirker C, Höger H, Ambros IM, Ambros PF, Berger W, Bittner RE. DNA damage, somatic aneuploidy, and malignant sarcoma susceptibility in muscular dystrophies. PLoS Genet 2011; 7:e1002042. [PMID: 21533183 PMCID: PMC3077392 DOI: 10.1371/journal.pgen.1002042] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 02/18/2011] [Indexed: 11/18/2022] Open
Abstract
Albeit genetically highly heterogeneous, muscular dystrophies (MDs) share a convergent pathology leading to muscle wasting accompanied by proliferation of fibrous and fatty tissue, suggesting a common MD–pathomechanism. Here we show that mutations in muscular dystrophy genes (Dmd, Dysf, Capn3, Large) lead to the spontaneous formation of skeletal muscle-derived malignant tumors in mice, presenting as mixed rhabdomyo-, fibro-, and liposarcomas. Primary MD–gene defects and strain background strongly influence sarcoma incidence, latency, localization, and gender prevalence. Combined loss of dystrophin and dysferlin, as well as dystrophin and calpain-3, leads to accelerated tumor formation. Irrespective of the primary gene defects, all MD sarcomas share non-random genomic alterations including frequent losses of tumor suppressors (Cdkn2a, Nf1), amplification of oncogenes (Met, Jun), recurrent duplications of whole chromosomes 8 and 15, and DNA damage. Remarkably, these sarcoma-specific genetic lesions are already regularly present in skeletal muscles in aged MD mice even prior to sarcoma development. Accordingly, we show also that skeletal muscle from human muscular dystrophy patients is affected by gross genomic instability, represented by DNA double-strand breaks and age-related accumulation of aneusomies. These novel aspects of molecular pathologies common to muscular dystrophies and tumor biology will potentially influence the strategies to combat these diseases. All kinds of muscular dystrophies (MDs) are characterized by progressive muscle wasting due to life-long proliferation of precursor cells of myo- (muscle), fibro- (connective tissue), and lipogenic (fat) origin. Despite discovery of many MD genes over the past 25 years, MDs still represent debilitating, incurable diseases, which frequently lead to premature death. Thus, it is imperative to gain novel insights into the underlying MD pathomechanisms. Here, we show that different mouse models for the most common human MDs frequently develop skeletal musculature-associated tumors, presenting as complex sarcomas, consisting of myo-, lipo-, and fibrogenic compartments. Collectively, these tumors are characterized by profound genomic instability such as DNA damage, recurring mutations in cancer genes, and aberrant chromosome copy numbers. We also demonstrate the presence of these cancer-related aberrations in dystrophic muscles from MD mice prior to formation of visible sarcomas. Moreover, we discovered corresponding genomic lesions also in skeletal muscles from human MD patients, as well as stem cells cultured thereof, and show that genomic instability precedes muscle degeneration in MDs. We thus propose that cancer-like genomic instability represents a novel, unifying pathomechanism underlying the entire group of genetically distinct MDs, which will hopefully open new therapeutic avenues.
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Affiliation(s)
- Wolfgang M. Schmidt
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Mohammed H. Uddin
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Sandra Dysek
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Karin Moser-Thier
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Christine Pirker
- Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Harald Höger
- Division for Laboratory Animal Science and Genetics, Medical University of Vienna, Himberg, Austria
| | - Inge M. Ambros
- Children's Cancer Research Institute (CCRI), St. Anna Kinderkrebsforschung Association, Vienna, Austria
| | - Peter F. Ambros
- Children's Cancer Research Institute (CCRI), St. Anna Kinderkrebsforschung Association, Vienna, Austria
| | - Walter Berger
- Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Reginald E. Bittner
- Neuromuscular Research Department, Center of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
- * E-mail:
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21
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Papić L, Fischer D, Trajanoski S, Höftberger R, Fischer C, Ströbel T, Schmidt WM, Bittner RE, Schabhüttl M, Gruber K, Pieber TR, Janecke AR, Auer-Grumbach M. SNP-array based whole genome homozygosity mapping: a quick and powerful tool to achieve an accurate diagnosis in LGMD2 patients. Eur J Med Genet 2010; 54:214-9. [PMID: 21172462 PMCID: PMC3085821 DOI: 10.1016/j.ejmg.2010.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 12/04/2010] [Indexed: 12/20/2022]
Abstract
A large number of novel disease genes have been identified by homozygosity mapping and the positional candidate approach. In this study we used single nucleotide polymorphism (SNP) array-based, whole genome homozygosity mapping as the first step to a molecular diagnosis in the highly heterogeneous muscle disease, limb girdle muscular dystrophy (LGMD). In a consanguineous family, both affected siblings showed homozygous blocks on chromosome 15 corresponding to the LGMD2A locus. Direct sequencing of CAPN3, encoding calpain-3, identified a homozygous deletion c.483delG (p.Ile162SerfsX17). In a sporadic LGMD patient complete absence of caveolin-3 on Western blot was observed. However, a mutation in CAV3 could not be detected. Homozygosity mapping revealed a large homozygous block at the LGMD2I locus, and direct sequencing of FKRP encoding fukutin-related-protein detected the common homozygous c.826 C > A (p.Leu276Ile) mutation. Subsequent re-examination of this patient's muscle biopsy showed aberrant α-dystroglycan glycosylation. In summary, we show that whole-genome homozygosity mapping using low cost SNP arrays provides a fast and non-invasive method to identify disease-causing mutations in sporadic patients or sibs from consanguineous families in LGMD2. Furthermore, this is the first study describing that in addition to PTRF, encoding polymerase I and transcript release factor, FKRP mutations may cause secondary caveolin-3 deficiency.
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Affiliation(s)
- Lea Papić
- Department of Internal Medicine, Division of Diabetes and Metabolism, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
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22
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Koenig X, Mike A, Mille M, Cervenka R, Lukács P, Nagl K, Dang XB, Todt H, Bittner RE, Hilber K. Altered sodium channel function in dystrophin/utrophin-deficient cardiomyocytes. BMC Pharmacol 2010. [PMCID: PMC3016535 DOI: 10.1186/1471-2210-10-s1-a25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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23
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Hochmeister S, Bittner RE, Höger H, Lassmann H, Bradl M. The susceptibility to experimental autoimmune encephalomyelitis is not related to dysferlin-deficiency. Autoimmunity 2009; 42:235-41. [PMID: 19301206 DOI: 10.1080/08916930802716542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Recent observations suggested that dysferlin might play a role in the development of autoimmune central nervous system (CNS) inflammation. To address this issue, we studied the induction and effector phase of experimental autoimmune encephalomyelitis in C57BL/10 mice producing intact or functionally deficient dysferlin. We found that both types of mice showed identical T-cell and antibody responses against the immunogen, and developed CNS inflammation with identical clinical courses, frequencies, lesion distributions, sizes and compositions. These findings suggest that the presence or absence of dysferlin does not have any consequences for the triggering or effector phase of autoimmune CNS inflammation.
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Affiliation(s)
- Sonja Hochmeister
- Department of Neuroimmunology, Center for Brain Reseach, Medical University Vienna, Austria
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24
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Herbst R, Iskratsch T, Unger E, Bittner RE. Aberrant development of neuromuscular junctions in glycosylation-defective Large(myd) mice. Neuromuscul Disord 2009; 19:366-78. [PMID: 19346129 DOI: 10.1016/j.nmd.2009.02.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 02/17/2009] [Accepted: 02/27/2009] [Indexed: 01/13/2023]
Abstract
Mice deficient in the glycosyltransferase Large are characterized by severe muscle and central nervous system abnormalities. In this study, we show that the formation and maintenance of neuromuscular junctions in Large(myd) mice are greatly compromised. Neuromuscular junctions are not confined to the muscle endplate zone but are widely spread and are frequently accompanied by exuberant nerve sprouting. Nerve terminals are highly fragmented and binding of alpha-bungarotoxin to postsynaptic acetylcholine receptors (AChRs) is greatly reduced. In vitro, Large(myd) myotubes are responsive to agrin but produce aberrant AChR clusters, which are larger in area and less densely packed with AChRs. In addition, AChR expression on the cell surface is diminished suggesting that AChR assembly or transport is defective. These results together with the finding that O-linked glycosylation at neuromuscular junctions of Large(myd) mice is compromised indicate that the action of Large is necessary for proper neuromuscular junction development.
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Affiliation(s)
- Ruth Herbst
- Center for Brain Research, Medical University of Vienna, Vienna, Austria.
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25
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Rossmanith W, Freilinger M, Roka J, Raffelsberger T, Moser-Thier K, Prayer D, Bernert G, Bittner RE. Isolated cytochrome c oxidase deficiency as a cause of MELAS. J Med Genet 2007; 45:117-21. [DOI: 10.1136/jmg.2007.052076] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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26
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Schmidt WM, Kraus C, Höger H, Hochmeister S, Oberndorfer F, Branka M, Bingemann S, Lassmann H, Müller M, Macedo-Souza LI, Vainzof M, Zatz M, Reis A, Bittner RE. Mutation in the Scyl1 gene encoding amino-terminal kinase-like protein causes a recessive form of spinocerebellar neurodegeneration. EMBO Rep 2007; 8:691-7. [PMID: 17571074 PMCID: PMC1905899 DOI: 10.1038/sj.embor.7401001] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Revised: 04/30/2007] [Accepted: 04/30/2007] [Indexed: 01/31/2023] Open
Abstract
Here, we show that the murine neurodegenerative disease mdf (autosomal recessive mouse mutant 'muscle deficient') is caused by a loss-of-function mutation in Scyl1, disrupting the expression of N-terminal kinase-like protein, an evolutionarily conserved putative component of the nucleocytoplasmic transport machinery. Scyl1 is prominently expressed in neurons, and enriched at central nervous system synapses and neuromuscular junctions. We show that the pathology of mdf comprises cerebellar atrophy, Purkinje cell loss and optic nerve atrophy, and therefore defines a new animal model for neurodegenerative diseases with cerebellar involvement in humans.
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Affiliation(s)
- Wolfgang M Schmidt
- Neuromuscular Research Department, Center of Anatomy & Cell Biology, Medical University of Vienna, Währinger Strasse 13, A-1090 Vienna, Austria
- Department of Clinical Pharmacology, Section of Cardiovascular Medicine, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria
| | - Cornelia Kraus
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 10, D-91054 Erlangen, Germany
| | - Harald Höger
- Division for Laboratory Animal Science and Genetics, Medical University of Vienna, Brauhausgasse 34, A-2325 Himberg, Austria
| | - Sonja Hochmeister
- Center for Brain Research, Division of Neuroimmunology, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria
| | - Felicitas Oberndorfer
- Neuromuscular Research Department, Center of Anatomy & Cell Biology, Medical University of Vienna, Währinger Strasse 13, A-1090 Vienna, Austria
| | - Manuela Branka
- Neuromuscular Research Department, Center of Anatomy & Cell Biology, Medical University of Vienna, Währinger Strasse 13, A-1090 Vienna, Austria
| | - Sonja Bingemann
- Neuromuscular Research Department, Center of Anatomy & Cell Biology, Medical University of Vienna, Währinger Strasse 13, A-1090 Vienna, Austria
| | - Hans Lassmann
- Center for Brain Research, Division of Neuroimmunology, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria
| | - Markus Müller
- Department of Clinical Pharmacology, Section of Cardiovascular Medicine, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria
| | - Lúcia Inês Macedo-Souza
- Department of Biology, Institute of Biological Sciences and Center for Study of Human Genome, University of São Paulo, Rua do Matão, 277 Cidade Universitária, São Paulo, Brazil
| | - Mariz Vainzof
- Department of Biology, Institute of Biological Sciences and Center for Study of Human Genome, University of São Paulo, Rua do Matão, 277 Cidade Universitária, São Paulo, Brazil
| | - Mayana Zatz
- Department of Biology, Institute of Biological Sciences and Center for Study of Human Genome, University of São Paulo, Rua do Matão, 277 Cidade Universitária, São Paulo, Brazil
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 10, D-91054 Erlangen, Germany
| | - Reginald E Bittner
- Neuromuscular Research Department, Center of Anatomy & Cell Biology, Medical University of Vienna, Währinger Strasse 13, A-1090 Vienna, Austria
- Tel: +43 664 80016 37514; Fax: +43 1 4277 61198; E-mail:
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27
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Milic A, Daniele N, Lochmüller H, Mora M, Comi GP, Moggio M, Noulet F, Walter MC, Morandi L, Poupiot J, Roudaut C, Bittner RE, Bartoli M, Richard I. A third of LGMD2A biopsies have normal calpain 3 proteolytic activity as determined by an in vitro assay. Neuromuscul Disord 2007; 17:148-56. [PMID: 17236769 DOI: 10.1016/j.nmd.2006.11.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Revised: 11/06/2006] [Accepted: 11/21/2006] [Indexed: 10/23/2022]
Abstract
Limb-girdle muscular dystrophy type 2A (LGMD2A) is an autosomal recessive muscular disorder caused by mutations in the gene coding for calpain 3, a calcium-dependent protease. We developed an in vitro assay that can detect the proteolytic activity of calpain 3 in a muscle sample. This assay is based on the use of an inactive calpain 3 as a substrate for active calpain 3 molecules. A total of 79 human biopsies have been analysed using an unbiased single blind method. Results were confronted with the molecular diagnosis for confirmation. Proteolytic activity was either reduced or absent in 68% of LGMD2A biopsies. In the remaining 32%, normal proteolytic activity was found despite the presence of calpain 3 mutation(s), suggesting that other calpain 3 properties might be impaired to give rise to the LGMD2A phenotype. Our assay is easily adaptable to routine and appears to be more sensitive than common analysis by immunodetection.
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Affiliation(s)
- Astrid Milic
- Laboratory of Clinical Neurogenetics and Muscular Disorders, Zagreb University School of Medicine, Croatian Institute for Brain Research, Salata 12, 10000 Zagreb, Croatia
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28
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Hochmeister S, Grundtner R, Bauer J, Engelhardt B, Lyck R, Gordon G, Korosec T, Kutzelnigg A, Berger JJ, Bradl M, Bittner RE, Lassmann H. Dysferlin is a new marker for leaky brain blood vessels in multiple sclerosis. J Neuropathol Exp Neurol 2006; 65:855-65. [PMID: 16957579 DOI: 10.1097/01.jnen.0000235119.52311.16] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Dysferlin is a muscle protein involved in cell membrane repair and its deficiency is associated with muscular dystrophy. We describe that dysferlin is also expressed in leaky endothelial cells. In the normal central nervous system (CNS), dysferlin is only present in endothelial cells of circumventricular organs. In the inflamed CNS of patients with multiple sclerosis (MS) or in animals with experimental autoimmune encephalomyelitis, dysferlin reactivity is induced in endothelial cells and the expression is associated with vascular leakage of serum proteins. In MS, dysferlin expression in endothelial cells is not restricted to vessels with inflammatory cuffs but is also present in noninflamed vessels. In addition, many blood vessels with perivascular inflammatory infiltrates lack dysferlin expression in inactive lesions or in the normal-appearing white matter. In vitro, dysferlin can be induced in endothelial cells by stimulation with tumor necrosis factor-alpha. Hence, dysferlin is not only a marker for leaky brain vessels, but also reveals dissociation of perivascular inflammatory infiltrates and blood-brain barrier disturbance in multiple sclerosis.
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Affiliation(s)
- Sonja Hochmeister
- Division of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
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29
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von der Hagen M, Laval SH, Cree LM, Haldane F, Pocock M, Wappler I, Peters H, Reitsamer HA, Hoger H, Wiedner M, Oberndorfer F, Anderson LVB, Straub V, Bittner RE, Bushby KMD. The differential gene expression profiles of proximal and distal muscle groups are altered in pre-pathological dysferlin-deficient mice. Neuromuscul Disord 2005; 15:863-77. [PMID: 16288871 DOI: 10.1016/j.nmd.2005.09.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2005] [Revised: 08/23/2005] [Accepted: 09/06/2005] [Indexed: 10/25/2022]
Abstract
The selective pattern of muscle involvement is a key feature of muscular dystrophies. Dysferlinopathy is a good model for studying this process since it shows variable muscle involvement that can be highly selective even in individual patients. The transcriptomes of proximal and distal muscles from wildtype C57BL/10 and dysferlin deficient C57BL/10.SJL-Dysf mice at a prepathological stage were assessed using the Affymetrix oligonucleotide-microarray system. We detected significant variation in gene expression between proximal and distal muscle in wildtype mice. Dysferlin defiency, even in the absence of pathological changes, altered this proximal distal difference but with little specific overlap with previous microarray analyses of dysferlinopathy. In conclusion, proximal and distal muscle groups show distinct patterns of gene expression and respond differently to dysferlin deficiency. This has implications for the selection of muscles for future microarray analyses, and also offers new routes for investigating the selectivity of muscle involvement in muscular dystrophies.
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30
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Haubenberger D, Bittner RE, Rauch-Shorny S, Zimprich F, Mannhalter C, Wagner L, Mineva I, Vass K, Auff E, Zimprich A. Inclusion body myopathy and Paget disease is linked to a novel mutation in the VCP gene. Neurology 2005; 65:1304-5. [PMID: 16247064 DOI: 10.1212/01.wnl.0000180407.15369.92] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Mutations in the valosin-containing protein (VCP) on chromosome 9p13-p12 were recently found to be associated with hereditary inclusion body myopathy, Paget disease of the bone, and frontotemporal dementia (IBMPFD). We identified a novel missense mutation in the VCP gene (R159H; 688G>A) segregating with this disease in an Austrian family of four affected siblings, who exhibited progressive proximal myopathy and Paget disease of the bone but without clinical signs of dementia.
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Affiliation(s)
- D Haubenberger
- Department of Neurology, Medical University of Vienna, Vienna, Austria
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31
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Oezen I, Rossmanith W, Forss-Petter S, Kemp S, Voigtländer T, Moser-Thier K, Wanders RJ, Bittner RE, Berger J. Accumulation of very long-chain fatty acids does not affect mitochondrial function in adrenoleukodystrophy protein deficiency. Hum Mol Genet 2005; 14:1127-37. [PMID: 15772093 DOI: 10.1093/hmg/ddi125] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
X-linked adrenoleukodystrophy (X-ALD, OMIM 300100) is a severe inherited neurodegenerative disease, associated with the accumulation of very long-chain fatty acids (VLCFA). The recent unexpected observation that the accumulation of VLCFA in tissues of the Abcd1-deficient mouse model for X-ALD is not due to a deficiency in VLCFA degradation, led to the hypothesis that mitochondrial abnormalities might contribute to X-ALD pathology. Here, we report that in spite of substantial accumulation of VLCFA in whole muscle homogenates, normal VLCFA levels were detected in mitochondria obtained by organellar fractionation. Polarographic analyses of the respiratory chain as well as enzymatic assays of isolated muscle mitochondria revealed no differences between X-ALD and control mice. Moreover, analysis by electron microscopy, revealed normal size, structure and localization of mitochondria in muscle of both groups. Similar to the results obtained in skeletal muscle, the mitochondrial enzyme activities in brain homogenates of Abcd1-deficient and wild-type animals also did not differ. Finally, studies on mitochondrial oxidative phosphorylation in permeabilized human skin fibroblasts of X-ALD patients and controls revealed no abnormalities. Thus, we conclude that the accumulation of VLCFA per se does not cause mitochondrial abnormalities and vice versa-mitochondrial abnormalities are not responsible for the accumulation of VLCFA in X-ALD mice.
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Affiliation(s)
- Iris Oezen
- Center for Brain Research, Medical University Vienna, Vienna, Austria
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32
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Rossmanith W, Raffelsberger T, Roka J, Kornek B, Feucht M, Bittner RE. The expanding mutational spectrum of MERRF substitution G8361A in the mitochondrial tRNALys gene. Ann Neurol 2003; 54:820-3. [PMID: 14681892 DOI: 10.1002/ana.10753] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In a case of childhood-onset myoclonus epilepsy with "ragged-red fibers" (MERRF), a hitherto unreported mutation within the mitochondrial tRNA(Lys) gene was identified as the cause of the disease. Substitution G8361A was maternally inherited, heteroplasmic in all tissues tested, and correlated with mitochondrial dysfunction in individual muscle fibers. The growing number of MERRF-associated mutations within the tRNA(Lys) gene affirms the specific role of this mitochondrial tRNA in the pathogenesis of the disease.
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Affiliation(s)
- Walter Rossmanith
- Neuromuscular Research Department, Institute of Anatomy, University of Vienna Medical School, Währinger Strasse 13, 1090 Vienna, Austria
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33
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Sutton-Smith M, Morris HR, Grewal PK, Hewitt JE, Bittner RE, Goldin E, Schiffmann R, Dell A. MS screening strategies: investigating the glycomes of knockout and myodystrophic mice and leukodystrophic human brains. Biochem Soc Symp 2003:105-15. [PMID: 12655778 DOI: 10.1042/bss0690105] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The implementation of highly sensitive and rapid mass spectrometric screening strategies for defining the glycosylation repertoires of organs in knockout mice is helping to reveal the roles that glycans play in health and disease. Thus novel glycosylation pathways have been uncovered in two such knockouts, namely alpha-mannosidase II null mice and UDP-N-acetylglucosamine: alpha 6-D-mannoside beta 1,2-N-acetylglucosaminyltransferase II null mice. This chapter documents the glycosylation profiles of a wide range of organs from the normal mouse which should facilitate future glycomics studies of knockout mice. Furthermore, we report applications of our screening technology in studies of the myodystrophy mouse and a human leukodystrophy.
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Affiliation(s)
- Mark Sutton-Smith
- Department of Biological Sciences, Imperial College of Science, Technology and Medicine, London SW7 2AY, U.K
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34
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Fricker RM, Raffelsberger T, Rauch-Shorny S, Finsterer J, Müller-Reible C, Gilly H, Bittner RE. Positive malignant hyperthermia susceptibility in vitro test in a patient with mitochondrial myopathy and myoadenylate deaminase deficiency. Anesthesiology 2002; 97:1635-7. [PMID: 12459698 DOI: 10.1097/00000542-200212000-00044] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Ruth M Fricker
- Department of Anesthesiology and General Intensive Care, University of Vienna, Waehringer Strasse 13, A-1090 Vienna, Austria
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35
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Holzfeind PJ, Grewal PK, Reitsamer HA, Kechvar J, Lassmann H, Hoeger H, Hewitt JE, Bittner RE. Skeletal, cardiac and tongue muscle pathology, defective retinal transmission, and neuronal migration defects in the Large(myd) mouse defines a natural model for glycosylation-deficient muscle - eye - brain disorders. Hum Mol Genet 2002; 11:2673-87. [PMID: 12354792 DOI: 10.1093/hmg/11.21.2673] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have recently shown that a deletion in the Large gene, encoding a putative glycosyltransferase, is the molecular defect underlying the myodystrophy (previously myd; now Large(myd)) mouse. Here we show that the muscular dystrophy phenotype is not confined to skeletal muscle, but is also present in the heart and tongue. Immunohistochemistry indicates disruption of the dystrophin-associated glycoprotein complex (DGC) in skeletal and cardiac muscle. Quantitative western blotting shows a general increase in the expression of DGC proteins and of dysferlin and caveolin-3 in mutant skeletal muscle. In contrast, the expression of DGC proteins is reduced in cardiac muscle. Overlay assays show loss of laminin binding by alpha-dystroglycan in Large(myd) skeletal and cardiac muscle and in brain. We also show that the phenotype of Large(myd) mice is not restricted to muscular dystrophy, but also includes ophthalmic and central nervous system (CNS) defects. Electroretinograms of homozygous mutant mice show gross abnormalities of b-wave characteristics, indicative of a complex defect in retinal transmission. The laminar architecture of the cortices of the cerebrum and the cerebellum is disturbed, indicating defective neuronal migration. Thus, the phenotype of the Large(myd) mouse shows similarities to the heterogeneous group of human muscle eye brain diseases characterized by severe congenital muscular dystrophy, eye abnormalities and CNS neuronal migration defects. These diseases include Fukuyama-type muscular dystrophy and muscle-eye-brain disease, both of which are also due to mutations in predicted glycosylation enzymes. Therefore, the Large(myd) mouse represents an important animal model for studying the function of glycosylation in muscle, brain and retina.
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Affiliation(s)
- Paul J Holzfeind
- Neuromuscular Research Department, Institute of Anatomy, University of Vienna Medical School, 1090 Vienna, Austria
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36
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Barisic N, Bernert G, Ipsiroglu O, Stromberger C, Müller T, Gruber S, Prayer D, Moser E, Bittner RE, Stöckler-Ipsiroglu S. Effects of oral creatine supplementation in a patient with MELAS phenotype and associated nephropathy. Neuropediatrics 2002; 33:157-61. [PMID: 12200746 DOI: 10.1055/s-2002-33679] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
An 18-year-old male patient with MELAS phenotype and 2 previous episodes of cerebral stroke, recurrent seizures and nephropathy, was treated with creatine monohydrate after the acute onset of psychomental regression and changing states of somnolence and aggressive and agitated behaviour. These symptoms disappeared completely after 4 weeks of treatment with creatine after which the patient regained all his previous mental abilites. Brain (white matter) proton magnetic resonance spectroscopy (chemical shift imaging) performed at 6 and 12 months of treatment showed lactic acid (Lac) accumulation and high creatine (Cr) levels in relation to choline-containing compounds (Cho). Urinary creatinine excretion as an indicator of the muscle and brain creatine pool increased upon short-term (12 days) high-dosage creatine supplementation (20 g per day) while plasma creatinine concentrations as possible indicators both of increasing creatine pool and of renal insufficiency increased during the course (28 months) of low-dosage creatine supplementation (5 g per day). Deterioration of renal function was finally indicated by urea retention and by impairment of renal creatinine clearance. These observations suggest that creatine supplementation may have a neuroprotective effect in patients with MELAS and episodes of acute mental deterioration. Adverse effects of creatine supplementation on renal function must be considered especially in patients with preexisting nephropathy.
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Affiliation(s)
- N Barisic
- Department of Pediatrics, University of Vienna, Austria
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37
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Raffelsberger T, Rossmanith W, Thaller-Antlanger H, Bittner RE. CPEO associated with a single nucleotide deletion in the mitochondrial tRNA(Tyr) gene. Neurology 2001; 57:2298-301. [PMID: 11756614 DOI: 10.1212/wnl.57.12.2298] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In the muscle biopsy of a female patient with chronic progressive external ophthalmoplegia (CPEO), myopathy, and exercise intolerance, the heteroplasmic deletion of a single nucleotide (DeltaT5885) in the mitochondrial tRNA tyrosine gene (tRNA(Tyr)) was found. The mutation was associated with the mitochondrial phenotype of individual muscle fibers, suggesting a causal association of DeltaT5885 with the mitochondrial disease phenotype. The microdeletion was absent from the patient's and her relatives' blood, indicating a spontaneous somatic origin.
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Affiliation(s)
- T Raffelsberger
- Neuromuscular Research Department, Institute of Anatomy, University of Vienna, Austria
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38
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Grewal PK, Holzfeind PJ, Bittner RE, Hewitt JE. Mutant glycosyltransferase and altered glycosylation of alpha-dystroglycan in the myodystrophy mouse. Nat Genet 2001; 28:151-4. [PMID: 11381262 DOI: 10.1038/88865] [Citation(s) in RCA: 251] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Spontaneous and engineered mouse mutants have facilitated our understanding of the pathogenesis of muscular dystrophy and they provide models for the development of therapeutic approaches. The mouse myodystrophy (myd) mutation produces an autosomal recessive, neuromuscular phenotype. Homozygotes have an abnormal gait, show abnormal posturing when suspended by the tail and are smaller than littermate controls. Serum creatine kinase is elevated and muscle histology is typical of a progressive myopathy with focal areas of acute necrosis and clusters of regenerating fibers. Additional aspects of the phenotype include sensorineural deafness, reduced lifespan and decreased reproductive fitness. The myd mutation maps to mouse chromosome 8 at approximately 33 centimorgans (cM) (refs. 2, 4-7). Here we show that the gene mutated in myd encodes a glycosyltransferase, Large. The human homolog of this gene (LARGE) maps to chromosome 22q. In myd, an intragenic deletion of exons 4-7 causes a frameshift in the resultant mRNA and a premature termination codon before the first of the two catalytic domains. On immunoblots, a monoclonal antibody to alpha-dystroglycan (a component of the dystrophin-associated glycoprotein complex) shows reduced binding in myd, which we attribute to altered glycosylation of this protein. We speculate that abnormal post-translational modification of alpha-dystroglycan may contribute to the myd phenotype.
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Affiliation(s)
- P K Grewal
- Institute of Genetics, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
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39
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Vafiadaki E, Reis A, Keers S, Harrison R, Anderson LV, Raffelsberger T, Ivanova S, Hoger H, Bittner RE, Bushby K, Bashir R. Cloning of the mouse dysferlin gene and genomic characterization of the SJL-Dysf mutation. Neuroreport 2001; 12:625-9. [PMID: 11234777 DOI: 10.1097/00001756-200103050-00039] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The SJL mouse strain has been widely used as an animal model for experimental autoimmune encephalitis (EAE), inflammatory muscle disease and lymphomas and has also been used as a background strain for the generation of animal models for a variety of diseases including motor neurone disease, multiple sclerosis and atherosclerosis. Recently the SJL mouse was shown to have myopathy due to dysferlin deficiency, so that it can now be considered a natural animal model for limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy (MM). We have cloned the mouse dysferlin cDNA and analysis of the sequence shows that the mouse dysferlin gene is characterized by six C2 domain sequences and a C-terminal anchoring domain, with the human and the mouse dysferlin genes sharing > 90% sequence homology overall. Genomic analysis of the SJL mutation confirms that the 171 bp RNA deletion has arisen by exon skipping resulting from a splice site mutation. The identification of this mutation has implications for the various groups using this widely available mouse stock.
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Affiliation(s)
- E Vafiadaki
- School of Biochemistry and Genetics, University of Newcastle upon Tyne, UK
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40
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Meixner A, Haverkamp S, Wässle H, Führer S, Thalhammer J, Kropf N, Bittner RE, Lassmann H, Wiche G, Propst F. MAP1B is required for axon guidance and Is involved in the development of the central and peripheral nervous system. J Cell Biol 2000; 151:1169-78. [PMID: 11121433 PMCID: PMC2190583 DOI: 10.1083/jcb.151.6.1169] [Citation(s) in RCA: 153] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Microtubule-associated proteins such as MAP1B have long been suspected to play an important role in neuronal differentiation, but proof has been lacking. Previous MAP1B gene targeting studies yielded contradictory and inconclusive results and did not reveal MAP1B function. In contrast to two earlier efforts, we now describe generation of a complete MAP1B null allele. Mice heterozygous for this MAP1B deletion were not affected. Homozygous mutants were viable but displayed a striking developmental defect in the brain, the selective absence of the corpus callosum, and the concomitant formation of myelinated fiber bundles consisting of misguided cortical axons. In addition, peripheral nerves of MAP1B-deficient mice had a reduced number of large myelinated axons. The myelin sheaths of the remaining axons were of reduced thickness, resulting in a decrease of nerve conduction velocity in the adult sciatic nerve. On the other hand, the anticipated involvement of MAP1B in retinal development and gamma-aminobutyric acid C receptor clustering was not substantiated. Our results demonstrate an essential role of MAP1B in development and function of the nervous system and resolve a previous controversy over its importance.
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Affiliation(s)
- Arabella Meixner
- Institute of Biochemistry and Molecular Cell Biology, Vienna Biocenter, University of Vienna, A-1030 Vienna, Austria
| | - Silke Haverkamp
- Department of Neuroanatomy, Max-Planck-Institute for Brain Research, D-60528 Frankfurt, Germany
| | - Heinz Wässle
- Department of Neuroanatomy, Max-Planck-Institute for Brain Research, D-60528 Frankfurt, Germany
| | - Susanne Führer
- University of Veterinary Medicine, A-1210 Vienna, Austria
| | | | - Nina Kropf
- Neuromuscular Research Department, University of Vienna, A-1090 Vienna, Austria
| | - Reginald E. Bittner
- Neuromuscular Research Department, University of Vienna, A-1090 Vienna, Austria
| | - Hans Lassmann
- Institute for Brain Research, University of Vienna, A-1090 Vienna, Austria
| | - Gerhard Wiche
- Institute of Biochemistry and Molecular Cell Biology, Vienna Biocenter, University of Vienna, A-1030 Vienna, Austria
| | - Friedrich Propst
- Institute of Biochemistry and Molecular Cell Biology, Vienna Biocenter, University of Vienna, A-1030 Vienna, Austria
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41
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Regele HM, Fillipovic E, Langer B, Poczewki H, Kraxberger I, Bittner RE, Kerjaschki D. Glomerular expression of dystroglycans is reduced in minimal change nephrosis but not in focal segmental glomerulosclerosis. J Am Soc Nephrol 2000; 11:403-412. [PMID: 10703664 DOI: 10.1681/asn.v113403] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Extensive flattening of podocyte foot processes and increased permeability of the glomerular capillary filter are the major pathologic features of minimal change nephrosis (MCN) and focal segmental glomerulosclerosis (FSGS). Adhesion proteins anchor and stabilize podocytes on the glomerular basement membrane (GBM), and presumably are involved in the pathogenesis of foot process flattening. Thus far, ao3 P,-integrin was localized to basal cell membrane domains. In this report, ao- and 3-dystroglycan (DG) were detected at precisely the sa-ne location by immunoelectron microscopy. and the presence of ac- and /-DG chains was confirmed by immunoblotting on isolated human glomeruli. Because the major DG binding partners in the GBM (laminin, agrin, perlecan), and the intracellular dystrophin analogue utrophin are also present in glomeruli, it appears that podocytes adhere to the GBM via DG complexes, similar to muscle fibers in which actin is linked via dystrophin and DG to the extracellular matrix. As with muscle cells, it is therefore plausible that podocytes use precisely actin-guided DG complexes at their "soles" to actively govern the topography of GBM matrix proteins. Expression of the a//3-DG complex was reported to be reduced in muscular dystrophies. and therefore a search for similar pathologic alterations in archival kidney biopsies from patients with MCN (it = 16) and FSGS (ni = 8) was conducted by quantitative immunoelectron microscopy. The density of a-DG on the podocyte's soles was significantly reduced to 25% in MCN, whereas it was not different in normal kidneys and FSGS. The expression of 3-DG was reduced to >50% in MCN, and was slightly increased in FSGS. Levels of DG expression returned to normal in MCN after steroid treatment (7 = 4). Expression of /3-integrin remained at normal levels in all conditions. These findings point to different potentially pathogenic mechanisms of foot process flattening in MCN and FSGS.
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Affiliation(s)
- Heinrich M Regele
- Institute for Clinical Pathology, University of Vienna, Allgemeines Krankenhaus, Austria
| | - Edith Fillipovic
- Institute for Clinical Pathology, University of Vienna, Allgemeines Krankenhaus, Austria
| | - Brigitte Langer
- Institute for Clinical Pathology, University of Vienna, Allgemeines Krankenhaus, Austria
| | - Helga Poczewki
- Institute for Clinical Pathology, University of Vienna, Allgemeines Krankenhaus, Austria
| | - Ilse Kraxberger
- Institute for Clinical Pathology, University of Vienna, Allgemeines Krankenhaus, Austria
| | - Reginald E Bittner
- Institute of Anatomy, Neuromuscular Research Department, University of Vienna, Vienna, Austria
| | - Dontscho Kerjaschki
- Institute for Clinical Pathology, University of Vienna, Allgemeines Krankenhaus, Austria
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42
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Finsterer J, Bittner RE, Grimm M. Cardiac involvement in Becker's muscular dystrophy, necessitating heart transplantation, 6 years before apparent skeletal muscle involvement. Neuromuscul Disord 1999; 9:598-600. [PMID: 10619719 DOI: 10.1016/s0960-8966(99)00045-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In Becker's muscular dystrophy cardiac abnormalities usually occur after onset of neuromuscular symptoms. We describe a Becker muscular dystrophy patient in whom chronic heart failure, necessitating cardiac transplantation, was the initial manifestation. Neuromuscular symptoms occurred not earlier than 6 years after the initial cardiac symptoms and 5 years after heart transplantation. In conclusion, severe heart failure due to dilated cardiomyopathy may be the initial manifestation of Becker's muscular dystrophy and may predate neuromuscular symptoms for years.
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Affiliation(s)
- J Finsterer
- Ludwig Boltzmann Institute for Research in Epilepsy and Neuromuscular Disorders, Vienna, Austria.
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43
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Reipert S, Steinböck F, Fischer I, Bittner RE, Zeöld A, Wiche G. Association of mitochondria with plectin and desmin intermediate filaments in striated muscle. Exp Cell Res 1999; 252:479-91. [PMID: 10527638 DOI: 10.1006/excr.1999.4626] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Plectin (M(r) > 500,000) is a versatile and widely expressed cytolinker protein. In striated muscle it is predominantly found at the Z-disc level where it colocalizes with the intermediate filament protein desmin. Both proteins show altered labeling patterns in tissues of muscular dystrophy patients. Moreover, mutations in the plectin gene lead to the autosomal recessive human disorder epidermolysis bullosa simplex with muscular dystrophy, and defects in the desmin gene have been shown to cause familiar cardiac and skeletal myopathy. Since intermediate filaments (IFs) in striated muscle tissue have been found to be intimately associated with mitochondria, we investigated whether plectin is involved in this association. Using postembedding immunogold labeling of Lowicryl sections and immunogold labeling of ultrathin cryosections, we show that plectin is associated with desmin IFs linking myofibrils to mitochondria at the level of the Z-disc and along the entire length of the sarcomere. The localization of plectin label at the mitochondrial membrane itself was consistent with a putative linker function of plectin between desmin IFs and the mitochondrial surface. In mitochondrion-rich muscle fibers, both plectin and desmin were part of an ordered arrangement of mitochondrial side branches, which wound around myofibrils adjacent to the Z-discs and were anchored into a filamentous network transversing from one fibril to the other. The association of mitochondria with plectin and IFs was seen also in tissues without regular distribution patterns of mitochondria, such as heart muscle and neonatal skeletal muscle tissues. These data were supplemented with in vitro binding assays showing direct interaction of plectin with desmin via its carboxy-terminal IF-binding domain. As a cytolinker protein associated with mitochondria and desmin IFs, plectin could play an important role in the positioning and shape formation, in particular branching, of mitochondrial organelles in striated muscle tissues.
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Affiliation(s)
- S Reipert
- Institute of Biochemistry, Vienna Biocenter, Vienna, 1030, Austria
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44
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Bittner RE, Anderson LV, Burkhardt E, Bashir R, Vafiadaki E, Ivanova S, Raffelsberger T, Maerk I, Höger H, Jung M, Karbasiyan M, Storch M, Lassmann H, Moss JA, Davison K, Harrison R, Bushby KM, Reis A. Dysferlin deletion in SJL mice (SJL-Dysf) defines a natural model for limb girdle muscular dystrophy 2B. Nat Genet 1999; 23:141-2. [PMID: 10508505 DOI: 10.1038/13770] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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45
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Bittner RE, Schöfer C, Weipoltshammer K, Ivanova S, Streubel B, Hauser E, Freilinger M, Höger H, Elbe-Bürger A, Wachtler F. Recruitment of bone-marrow-derived cells by skeletal and cardiac muscle in adult dystrophic mdx mice. Anat Embryol (Berl) 1999; 199:391-6. [PMID: 10221450 DOI: 10.1007/s004290050237] [Citation(s) in RCA: 322] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It is commonly accepted, that regenerative capacity of striated muscle is confined to skeletal muscle by activation of satellite cells that normally reside quiescent between the plasmalemma and the basement membrane of muscle fibers. Muscular dystrophies are characterized by repetitive cycles of de- and regeneration of skeletal muscle fibers and by the frequent involvement of the cardiac muscle. Since during the longstanding course of muscular dystrophies there is a permanent demand of myogenic progenitors we hypothesized that this may necessitate a recruitment of additional myogenic precursors from an undifferentiated, permanently renewed cell pool, such as bone marrow (BM) cells. To this end normal and dystrophic (mdx) female mice received bone marrow transplantation (BMT) from normal congenic male donor mice. After 70 days, histological sections of skeletal and cardiac muscle from BMT mice were probed for the donor-derived Y chromosomes. In normal BMT recipients, no Y chromosome-containing myonuclei were detected, either in skeletal or in cardiac muscle. However, in all samples from dystrophic mdx skeletal muscles Y chromosome-specific signals were detected within muscle fiber nuclei, which additionally were found to express the myoregulatory proteins myogenin and myf-5. Moreover, in the hearts of BMT-mdx mice single cardiomyocytes with donor derived nuclei were identified, indicating, that even cardiac muscle cells are able to regenerate by recruitment of circulating BM-derived progenitors. Our findings suggest that further characterization and identification of the BM cells capable of undergoing myogenic differentiation may have an outstanding impact on therapeutic strategies for diseases of skeletal and cardiac muscle.
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Affiliation(s)
- R E Bittner
- Institute of Anatomy, Department 3, University of Vienna, Austria.
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46
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Finsterer J, Schwerer B, Bittner RE, Mamoli B. Cerebrospinal fluid filtration and immunoglobulins in multifocal motor neuropathy. Clin Neuropathol 1999; 18:31-6. [PMID: 9988136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
Cerebrospinal fluid (CSF) filtration has been shown to be of benefit in chronic inflammatory, demyelinating polyneuropathy, but has not been applied to multifocal motor neuropathy (MMN) so far. Twenty-seven months after a 48-year-old male patient had developed slowly progressive, distally prominent monoparesis of the left arm, MMN was diagnosed. Conduction blocks were found in the left brachial plexus after median, ulnar, and radial nerve stimulation. Serum anti-GM1 antibody titers were markedly increased. Biopsy of the motor long thoracic nerve showed reduction of small caliber myelinated axons and irregularly shaped myelin lamellae. Treatment with immunoglobulins 29, 31, 36, and 39 months after onset was followed by a distinct improvement each time. Thirty-four months after onset, one liter CSF was filtered off by means of a bidirectional syringe pump with only minor therapeutic effect. In conclusion, immunoglobulins had a stronger therapeutic effect than CSF filtration on the MMN patient described.
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Affiliation(s)
- J Finsterer
- Ludwig Boltzmann Institute for Research in Epilepsy and Neuromuscular Disorders, University of Vienna, Austria
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Finsterer J, Shorny S, Capek J, Cerny-Zacharias C, Pelzl B, Messner R, Bittner RE, Mamoli B. Lactate stress test in the diagnosis of mitochondrial myopathy. J Neurol Sci 1998; 159:176-80. [PMID: 9741404 DOI: 10.1016/s0022-510x(98)00170-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of the study was to determine the sensitivity and specificity of the lactate stress test in the detection of mitochondrial myopathies. Thirty one healthy subjects, 10 patients with non-mitochondrial myopathy and 26 patients with mitochondrial myopathy underwent lactate stress testing at a standardized workload of 30 W during 15 min on a bicycle ergometer. Lactate was determined before the exercise (R1), 5, 10, 15 min after starting the exercise (S5, S10, S15) and 15 min after finishing the exercise (R2). A result was interpreted as pathologic if more than two of the five lactate values were above the corresponding upper reference limits. The upper reference limits for the venous lactate at R1, S5, S10, S15 and R2 were 1.9, 2.0, 2.1, 2.0 and 1.7 mmol/l respectively. The lactate stress test was pathologic in 1/10 of the non-mitochondrial myopathies and in 18/26 of the mitochondrial myopathies. The sensitivity of the lactate stress test was 69%. The specificity of the test was 90%. In conclusion, the lactate stress test proved to be helpful for evaluating the integrity of the oxidative metabolism in the majority of patients with mitochondrial myopathy.
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Affiliation(s)
- J Finsterer
- Ludwig Boltzmann Institute for Research in Neuromuscular Disorders, Vienna, Austria
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Abstract
The association between malignant hyperthermia (MH) and neuromuscular disorders is controversial. An association between MH and Duchenne muscular dystrophy, a common and lethal disorder caused by deficiency of dystrophin, has been reported sporadically but is still not proved. To examine this problem, we performed halothane and caffeine in vitro contracture tests on skeletal muscles from dystrophin deficient mdx mice, an animal model for human Duchenne muscular dystrophy. As neither halothane nor caffeine triggered abnormal responses in mdx muscles, we conclude that dystrophin deficiency per se is not the primary cause of MH-like crises, as reported for patients with Duchenne muscular dystrophy.
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Affiliation(s)
- N Mader
- Neuromuscular Research Department, University of Vienna, Austria
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Gilly H, Musat I, Fricker R, Bittner RE, Steinbereithner K, Kress HG. Classification of Malignant Hyperthermia-Equivocal Patients by 4-Chloro-M-Cresol. Anesth Analg 1997. [DOI: 10.1213/00000539-199707000-00027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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