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Galea CA, Huq A, Lockhart PJ, Tai G, Corben LA, Yiu EM, Gurrin LC, Lynch DR, Gelbard S, Durr A, Pousset F, Parkinson M, Labrum R, Giunti P, Perlman SL, Delatycki MB, Evans-Galea MV. Compound heterozygous FXN mutations and clinical outcome in friedreich ataxia. Ann Neurol 2016; 79:485-95. [PMID: 26704351 DOI: 10.1002/ana.24595] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/16/2015] [Accepted: 12/17/2015] [Indexed: 02/01/2023]
Abstract
OBJECTIVE Friedreich ataxia (FRDA) is an inherited neurodegenerative disease characterized by ataxia and cardiomyopathy. Homozygous GAA trinucleotide repeat expansions in the first intron of FXN occur in 96% of affected individuals and reduce frataxin expression. Remaining individuals are compound heterozygous for a GAA expansion and a FXN point/insertion/deletion mutation. We examined disease-causing mutations and the impact on frataxin structure/function and clinical outcome in FRDA. METHODS We compared clinical information from 111 compound heterozygotes and 131 individuals with homozygous expansions. Frataxin mutations were examined using structural modeling, stability analyses and systematic literature review, and categorized into four groups: (1) homozygous expansions, and three compound heterozygote groups; (2) null (no frataxin produced); (3) moderate/strong impact; and (4) minimal impact. Mean age of onset and the presence of cardiomyopathy and diabetes mellitus were compared using regression analyses. RESULTS Mutations in the hydrophobic core of frataxin affected stability whereas surface residue mutations affected interactions with iron sulfur cluster assembly and heme biosynthetic proteins. The null group of compound heterozygotes had significantly earlier age of onset and increased diabetes mellitus, compared to the homozygous expansion group. There were no significant differences in mean age of onset between homozygotes and the minimal and moderate/strong impact groups. INTERPRETATION In compound heterozygotes, expression of partially functional mutant frataxin delays age of onset and reduces diabetes mellitus, compared to those with no frataxin expression from the non-expanded allele. This integrated analysis of categorized frataxin mutations and their correlation with clinical outcome provide a definitive resource for investigating disease pathogenesis in FRDA.
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Affiliation(s)
- Charles A Galea
- Medicinal Chemistry and Drug Delivery, Disposition and Dynamics (D4), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Bruce Lefroy Centre, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Aamira Huq
- Bruce Lefroy Centre, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Paul J Lockhart
- Bruce Lefroy Centre, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Geneieve Tai
- Bruce Lefroy Centre, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
| | - Louise A Corben
- Bruce Lefroy Centre, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
- School of Psychological Sciences, Monash University, Clayton, Victoria, Australia
| | - Eppie M Yiu
- Bruce Lefroy Centre, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
- Department of Neurology, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Lyle C Gurrin
- Center for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - David R Lynch
- Departments of Neurology and Pediatrics, University of Pennsylvania School of Medicine and The Children's Hospital of Philadelphia, Philadelphia, PA
| | - Sarah Gelbard
- Departments of Neurology and Pediatrics, University of Pennsylvania School of Medicine and The Children's Hospital of Philadelphia, Philadelphia, PA
| | - Alexandra Durr
- APHP, Department of Genetics and Cytogenetics, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
- Institut du Cerveau et de la Moelle épinière (ICM), Pitié-Salpêtrière University Hospital, Paris, France
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S_1127, ICM, F-75013, France
| | - Francoise Pousset
- APHP, Cardiology Department, AP-HP Pitie-Salpétrière Hospital, Paris, France
| | - Michael Parkinson
- Department of Molecular Neuroscience, University College London Institute of Neurology, London, United Kingdom
| | - Robyn Labrum
- Department of Neurogenetics, University College London Hospital, Institute of Neurology, London, United Kingdom
| | - Paola Giunti
- Department of Molecular Neuroscience, University College London Institute of Neurology, London, United Kingdom
- Department of Neurogenetics, University College London Hospital, Institute of Neurology, London, United Kingdom
| | - Susan L Perlman
- Ataxia Center and Huntington Disease Center of Excellence, Department of Neurology, David Geffen School of Medicine at the University of California at Los Angeles, CA
| | - Martin B Delatycki
- Bruce Lefroy Centre, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
- School of Psychological Sciences, Monash University, Clayton, Victoria, Australia
- Clinical Genetics, Austin Health, Heidelberg, Victoria, Australia
| | - Marguerite V Evans-Galea
- Bruce Lefroy Centre, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
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Fukasawa Y, Tsuji J, Fu SC, Tomii K, Horton P, Imai K. MitoFates: improved prediction of mitochondrial targeting sequences and their cleavage sites. Mol Cell Proteomics 2015; 14:1113-26. [PMID: 25670805 PMCID: PMC4390256 DOI: 10.1074/mcp.m114.043083] [Citation(s) in RCA: 360] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Indexed: 01/25/2023] Open
Abstract
Mitochondria provide numerous essential functions for cells and their dysfunction leads to a variety of diseases. Thus, obtaining a complete mitochondrial proteome should be a crucial step toward understanding the roles of mitochondria. Many mitochondrial proteins have been identified experimentally but a complete list is not yet available. To fill this gap, methods to computationally predict mitochondrial proteins from amino acid sequence have been developed and are widely used, but unfortunately, their accuracy is far from perfect. Here we describe MitoFates, an improved prediction method for cleavable N-terminal mitochondrial targeting signals (presequences) and their cleavage sites. MitoFates introduces novel sequence features including positively charged amphiphilicity, presequence motifs, and position weight matrices modeling the presequence cleavage sites. These features are combined with classical ones such as amino acid composition and physico-chemical properties as input to a standard support vector machine classifier. On independent test data, MitoFates attains better performance than existing predictors in both detection of presequences and in predicting their cleavage sites. We used MitoFates to look for undiscovered mitochondrial proteins from 42,217 human proteins (including isoforms such as alternative splicing or translation initiation variants). MitoFates predicts 1167 genes to have at least one isoform with a presequence. Five-hundred and eighty of these genes were not annotated as mitochondrial in either UniProt or Gene Ontology. Interestingly, these include candidate regulators of parkin translocation to damaged mitochondria, and also many genes with known disease mutations, suggesting that careful investigation of MitoFates predictions may be helpful in elucidating the role of mitochondria in health and disease. MitoFates is open source with a convenient web server publicly available.
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Affiliation(s)
- Yoshinori Fukasawa
- From the ‡Department of Computational Biology, Graduate School of Frontier Sciences, The University Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Junko Tsuji
- From the ‡Department of Computational Biology, Graduate School of Frontier Sciences, The University Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Szu-Chin Fu
- From the ‡Department of Computational Biology, Graduate School of Frontier Sciences, The University Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
| | - Kentaro Tomii
- From the ‡Department of Computational Biology, Graduate School of Frontier Sciences, The University Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan; §Computational Biology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Paul Horton
- From the ‡Department of Computational Biology, Graduate School of Frontier Sciences, The University Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan; §Computational Biology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Kenichiro Imai
- §Computational Biology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
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Proteasome and Neurodegeneratıve Diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 109:397-414. [DOI: 10.1016/b978-0-12-397863-9.00011-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Stroumpoulis KI, Pantazopoulos IN, Xanthos TT. Hypertrophic cardiomyopathy and sudden cardiac death. World J Cardiol 2010; 2:289-98. [PMID: 21160605 PMCID: PMC2998829 DOI: 10.4330/wjc.v2.i9.289] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2010] [Revised: 07/19/2010] [Accepted: 07/26/2010] [Indexed: 02/06/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease that affects the left ventricle. HCM can appear at any age, with the majority of the patients remaining clinically stable. When patients complain of symptoms, these include: dyspnea, dizziness, syncope and angina. HCM can lead to sudden cardiac death (SCD), mainly due to ventricular tachyarrhythmia or ventricular tachycardia. High-risk patients benefit from implantable cardioverter-defibrillators. Left ventricular outflow tract obstruction is not a rare feature in HCM, especially in symptomatic patients, and procedures that abolish that obstruction provide positive and consistent results that can improve long-term survival. HCM is the most common cause of sudden death in young competitive athletes and preparticipation screening programs have to be implemented to avoid these tragic fatalities. The structure of these programs is a matter of large debate. Worldwide registries are necessary to identify the full extent of HCM-related SCD.
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Affiliation(s)
- Konstantinos I Stroumpoulis
- Konstantinos I Stroumpoulis, Department of Experimental Surgery and Surgical Research, Medical School, University of Athens, 11527, Athens, Greece
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Santos R, Lefevre S, Sliwa D, Seguin A, Camadro JM, Lesuisse E. Friedreich ataxia: molecular mechanisms, redox considerations, and therapeutic opportunities. Antioxid Redox Signal 2010; 13:651-90. [PMID: 20156111 PMCID: PMC2924788 DOI: 10.1089/ars.2009.3015] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 02/08/2010] [Accepted: 02/14/2010] [Indexed: 12/14/2022]
Abstract
Mitochondrial dysfunction and oxidative damage are at the origin of numerous neurodegenerative diseases like Friedreich ataxia and Alzheimer and Parkinson diseases. Friedreich ataxia (FRDA) is the most common hereditary ataxia, with one individual affected in 50,000. This disease is characterized by progressive degeneration of the central and peripheral nervous systems, cardiomyopathy, and increased incidence of diabetes mellitus. FRDA is caused by a dynamic mutation, a GAA trinucleotide repeat expansion, in the first intron of the FXN gene. Fewer than 5% of the patients are heterozygous and carry point mutations in the other allele. The molecular consequences of the GAA triplet expansion is transcription silencing and reduced expression of the encoded mitochondrial protein, frataxin. The precise cellular role of frataxin is not known; however, it is clear now that several mitochondrial functions are not performed correctly in patient cells. The affected functions include respiration, iron-sulfur cluster assembly, iron homeostasis, and maintenance of the redox status. This review highlights the molecular mechanisms that underlie the disease phenotypes and the different hypothesis about the function of frataxin. In addition, we present an overview of the most recent therapeutic approaches for this severe disease that actually has no efficient treatment.
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Affiliation(s)
- Renata Santos
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
| | - Sophie Lefevre
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
- University Pierre et Marie Curie, Paris, France
| | - Dominika Sliwa
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
| | - Alexandra Seguin
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
| | - Jean-Michel Camadro
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
| | - Emmanuel Lesuisse
- Mitochondria, Metals and Oxidative Stress Laboratory, Institut Jacques Monod (UMR 7592 CNRS–University Paris-Diderot), Paris, France
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Abstract
Sudden cardiac death (SCD) is one of the most common causes of death. An important number of sudden deaths, especially in the young, are due to genetic heart disorders, both with structural and arrhythmogenic abnormalities. In recent years, significant advances have been made in understanding the genetic basis of SCD. Identification of the genetic causes of sudden death is important because close relatives are also at potential risk of having a fatal cardiac condition. A comprehensive post-mortem investigation is vital to determine the cause and manner of death and provides the opportunity to assess the potential risk to the family after appropriate genetic counselling. In this paper, we present an update of the different genetic causes of sudden death, emphasizing their importance for the forensic pathologist due to his relevant role in the diagnosis and prevention of SCD.
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Olivotto I, Girolami F, Ackerman MJ, Nistri S, Bos JM, Zachara E, Ommen SR, Theis JL, Vaubel RA, Re F, Armentano C, Poggesi C, Torricelli F, Cecchi F. Myofilament protein gene mutation screening and outcome of patients with hypertrophic cardiomyopathy. Mayo Clin Proc 2008; 83:630-8. [PMID: 18533079 DOI: 10.4065/83.6.630] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To determine the influence of a positive genetic test for hypertrophic cardiomyopathy (HCM) on clinical outcome. PATIENTS AND METHODS A cohort of 203 unrelated patients with HCM (mean +/- SD age, 50+/-18 years) was enrolled from January 1, 2002, through December 31, 2003. They were followed up for a mean +/- SD time of 4.0+/-1.7 years after genetic testing of the 8 HCM-susceptibility genes that encode key sarcomeric/myofilament proteins. The clinical phenotype of those with a positive genetic test (myofilament-positive HCM) was compared with those with a negative genetic test (myofilament-negative HCM). RESULTS In this cohort of 203 patients, 87 mutations were identified in 126 patients (myofilament-positive HCM, 62%); the remaining 77 patients (38%) were myofilament-negative. Despite similar baseline features, patients with myofilament-positive HCM showed increased risk of the combined end points of cardiovascular death, nonfatal stroke, or progression to New York Heart Association class III or IV compared with the patients with myofilament-negative HCM (25% vs 7%, respectively; independent hazard ratio, 4.27; P=.008). These end points occurred at any age among patients with myofilament-positive HCM (range, 14-86 years), but only in those aged 65 years and older among patients with myofilament-negative HCM. Moreover, patients with myofilament-positive HCM showed greater probability of severe left ventricular systolic and diastolic dysfunction, defined as an ejection fraction of less than 50% and a restrictive filling pattern (P=.02 and P<.02, respectively, vs myofilament-negative HCM). CONCLUSION Screening for sarcomere protein gene mutations in HCM identifies a broad subgroup of patients with increased propensity toward long-term impairment of left ventricular function and adverse outcome, irrespective of the myofilament (thick, intermediate, or thin) involved.
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Affiliation(s)
- Iacopo Olivotto
- Regional Referral Center for Myocardial Diseases, Azienda Ospedaliera-Universitaria Careggi and Università degli Studi, Florence, Italy.
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Gellera C, Castellotti B, Mariotti C, Mineri R, Seveso V, Didonato S, Taroni F. Frataxin gene point mutations in Italian Friedreich ataxia patients. Neurogenetics 2007; 8:289-99. [PMID: 17703324 DOI: 10.1007/s10048-007-0101-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Accepted: 07/19/2007] [Indexed: 11/29/2022]
Abstract
Friedreich ataxia (FRDA) is associated with a GAA-trinucleotide-repeat expansion in the first intron of the FXN gene (9q13-21), which encodes a 210-amino-acid protein named frataxin. More than 95% of patients are homozygous for 90-1,300 repeat expansion on both alleles. The remaining patients have been shown to be compound heterozygous for a GAA expansion on one allele and a micromutation on the other. The reduction of both frataxin messenger RNA (mRNA) and protein was found to be proportional to the size of the smaller GAA repeat allele. We report a clinical and molecular study of 12 families in which classical FRDA patients were heterozygous for a GAA expansion on one allele. Sequence analysis of the FXN gene allowed the identification of the second disease-causing mutation in each heterozygous patient, which makes this the second largest series of FRDA compound heterozygotes reported thus far. We have identified seven mutations, four of which are novel. Five patients carried missense mutations, whereas eight patients carried null (frameshift or nonsense) mutations. Quantitation of frataxin levels in lymphoblastoid cell lines derived from six compound heterozygous patients showed a statistically significant correlation of residual protein levels with the age at onset (r = 0.82, p < 0.05) or the GAA expansion (r = -0.76, p < 0.1). In the group of patients heterozygous for a null allele, a strong (r = -0.94, p < 0.01) correlation was observed between the size of GAA expansion and the age at onset, thus lending support to the hypothesis that the residual function of frataxin in patients' cells derive exclusively from the expanded allele.
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Affiliation(s)
- Cinzia Gellera
- UO Biochimica e Genetica, Fondazione IRCCS Istituto Neurologico "Carlo Besta", via Celoria 11, 20133 Milan, Italy
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Alcalai R, Seidman JG, Seidman CE. Genetic basis of hypertrophic cardiomyopathy: from bench to the clinics. J Cardiovasc Electrophysiol 2007; 19:104-10. [PMID: 17916152 DOI: 10.1111/j.1540-8167.2007.00965.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac disorder that characterized by marked thickening of the left ventricular wall that occurs in the absence of increased external load. HCM is the most common cause of sudden cardiac death under 35 years and in addition causes heart failure. HCM is usually inherited as an autosomal dominant mutation in genes that encode protein constituents of the sarcomere. To date, more than 450 different mutations have been identified within 13 myofilament-related genes. This review focuses current research involved in the discovery of other causative genes, investigation of the mechanisms by which sarcomere genes mutations produce hypertrophy and arrhythmia, and identification of modifying factors that influence clinical expression in HCM patients. The clinical implications of molecular advances in HCM are discussed.
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Affiliation(s)
- Ronny Alcalai
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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Abstract
PURPOSE OF REVIEW Hypertrophic cardiomyopathy is the most common identifiable cause of sudden death in the young. This review details the history of hypertrophic cardiomyopathy, recent discoveries in its genetic underpinnings and important genotype-phenotype relationships described in recent studies. RECENT FINDINGS Since the discovery of the genetic underpinnings of hypertrophic cardiomyopathy in 1989 hundreds of mutations scattered among at least 10 sarcomeric genes confer the pathogenetic substrate for this 'disease of the sarcomere/myofilament'. More recently, the genetic spectrum of hypertrophic cardiomyopathy has expanded to encompass mutations in Z-disc-associated genes (Z-disc hypertrophic cardiomyopathy) and glycogen storage diseases mimicking hypertrophic cardiomyopathy (metabolic hypertrophic cardiomyopathy). Recent genotype-phenotype studies have discovered an important relationship between the morphology of the left ventricle, its underlying genetic substrate and the long-term outcome of this disease. SUMMARY Genomic medicine has entered clinical practice and the diagnostic utility of genetic testing for hypertrophic cardiomyopathy is clearly evident, but with the growing number of hypertrophic cardiomyopathy-associated genes strategic choices have to be made. With recent discoveries in genotype-phenotype relationships, especially pertaining to the echocardiographic septal shape and the underlying pathogenetic mutation, time has come to subdivide the one disease we call hypertrophic cardiomyopathy.
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Affiliation(s)
- J Martijn Bos
- Mayo Clinic Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic College of Medicine, Rochester, MN, USA
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Berndt C, Lillig CH, Holmgren A. Thiol-based mechanisms of the thioredoxin and glutaredoxin systems: implications for diseases in the cardiovascular system. Am J Physiol Heart Circ Physiol 2006; 292:H1227-36. [PMID: 17172268 DOI: 10.1152/ajpheart.01162.2006] [Citation(s) in RCA: 246] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Reactive oxygen species (ROS) and the cellular thiol redox state are crucial mediators of multiple cell processes like growth, differentiation, and apoptosis. Excessive ROS production or oxidative stress is associated with several diseases, including cardiovascular disorders like ischemia-reperfusion. To prevent ROS-induced disorders, the heart is equipped with effective antioxidant systems. Key players in defense against oxidative stress are members of the thioredoxin-fold family of proteins. Of these, thioredoxins and glutaredoxins maintain a reduced intracellular redox state in mammalian cells by the reduction of protein thiols. The reversible oxidation of Cys-Gly-Pro-Cys or Cys-Pro(Ser)-Tyr-Cys active site cysteine residues is used in reversible electron transport. Thioredoxins and glutaredoxins belong to corresponding systems consisting of NADPH, thioredoxin reductase, and thioredoxin or NADPH, glutathione reductase, glutathione, and glutaredoxin, respectively. Thioredoxin as well as glutaredoxin activities appear to be very important for the progression and severity of several cardiovascular disorders. These proteins function not only as antioxidants, they inhibit or activate apoptotic signaling molecules like apoptosis signal-regulating kinase 1 and Ras or transcription factors like NF-kappaB. Thioredoxin activity is regulated by the endogenous inhibitor thioredoxin-binding protein 2 (TBP-2), indicating an important role of the balance between thioredoxin and TBP-2 levels in cardiovascular diseases. In this review, we will summarize cardioprotective effects of endogenous thioredoxin and glutaredoxin systems as well as the high potential in clinical applications of exogenously applied thioredoxin or glutaredoxin or the induction of endogenous thioredoxin and glutaredoxin systems.
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Affiliation(s)
- Carsten Berndt
- The Medical Nobel Inst for Biochemistry, Dept of Medical Biochemistry and Biophysics, Karolinska Inst, SE-17177 Stockholm, Sweden
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Whitnall M, Richardson DR. Iron: a new target for pharmacological intervention in neurodegenerative diseases. Semin Pediatr Neurol 2006; 13:186-97. [PMID: 17101458 DOI: 10.1016/j.spen.2006.08.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Iron (Fe) is an essential element that is imperative for the redox-driven processes of oxygen transport, electron transport, and DNA synthesis. However, in the absence of appropriate storage or chelation, excess-free Fe readily participates in the formation of toxic-free radicals, inducing oxidative stress and apoptosis. A growing body of evidence suggests that Fe may play some role in neurodegenerative diseases such as Huntington disease, Alzheimer's disease, Parkinson's disease, and particularly Friedreich's ataxia. This review examines the role of Fe in the pathology of these conditions and the potential use of Fe chelators as therapeutic agents for the treatment of neurodegenerative disorders. Consideration is given to the features that comprise a clinically successful Fe chelator, with focus on the development of ligands such as desferrioxamine, clioquinol, pyridoxal isonicotinoyl hydrazone, and other novel aroylhydrazones.
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Affiliation(s)
- Megan Whitnall
- Iron Metabolism and Chelation Program, Department of Pathology, University of Sydney, Sydney, New South Wales, Australia
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Bos JM, Poley RN, Ny M, Tester DJ, Xu X, Vatta M, Towbin JA, Gersh BJ, Ommen SR, Ackerman MJ. Genotype-phenotype relationships involving hypertrophic cardiomyopathy-associated mutations in titin, muscle LIM protein, and telethonin. Mol Genet Metab 2006; 88:78-85. [PMID: 16352453 PMCID: PMC2756511 DOI: 10.1016/j.ymgme.2005.10.008] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Accepted: 10/24/2005] [Indexed: 12/01/2022]
Abstract
BACKGROUND TTN-encoded titin, CSRP3-encoded muscle LIM protein, and TCAP-encoded telethonin are Z-disc proteins essential for the structural organization of the cardiac sarcomere and the cardiomyocyte's stretch sensor. All three genes have been established as cardiomyopathy-associated genes for both dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). Here, we sought to characterize the frequency, spectrum, and phenotype associated with HCM-associated mutations in these three genes in a large cohort of unrelated patients evaluated at a single tertiary outpatient center. METHODS DNA was obtained from 389 patients with HCM (215 male, left ventricular wall thickness of 21.6+/-6 mm) and analyzed for mutations involving all translated exons of CSRP3 and TCAP and targeted HCM-associated exons (2, 3, 4, and 14) of TTN using polymerase chain reaction (PCR), denaturing high performance liquid chromatography (DHPLC), and direct DNA sequencing. Clinical data were extracted from patient records and maintained independent of the genotype. RESULTS Overall, 16 patients (4.1%) harbored a Z-disc mutation: 12 had a MLP mutation and 4 patients a TCAP mutation. No TTN mutations were detected. Seven patients were also found to have a concomitant myofilament mutation. Seven patients with a MLP-mutation were found to harbor the DCM-associated, functionally characterized W4R mutation. W4R-MLP was also noted in a single white control subject. Patients with MLP/TCAP-associated HCM clinically mimicked myofilament-HCM. CONCLUSIONS Approximately 4.1% of unrelated patients had HCM-associated MLP or TCAP mutations. MLP/TCAP-HCM phenotypically mirrors myofilament-HCM and is more severe than the subset of patients who still remain without a disease-causing mutation. The precise role of W4R-MLP in the pathogenesis of either DCM or HCM warrants further investigation.
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Affiliation(s)
- J. Martijn Bos
- Department of Internal Medicine, Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Rainer N. Poley
- Mayo Medical School, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Melissa Ny
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - David J. Tester
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Matteo Vatta
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX, USA
- Department of Reproductive and Developmental Sciences, University of Trieste, Trieste, Italy
| | - Jeffrey A. Towbin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX, USA
| | - Bernard J. Gersh
- Department of Internal Medicine, Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Steve R. Ommen
- Department of Internal Medicine, Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Michael J. Ackerman
- Department of Internal Medicine, Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
- Department of Pediatrics, Division of Pediatric Cardiology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
- Corresponding author. Fax: +1 507 284 3757. E-mail address: (M.J. Ackerman)
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