1
|
Said I, Barbash DA, Clark AG. The Structure of Simple Satellite Variation in the Human Genome and Its Correlation With Centromere Ancestry. Genome Biol Evol 2024; 16:evae153. [PMID: 39018452 PMCID: PMC11305138 DOI: 10.1093/gbe/evae153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 06/21/2024] [Accepted: 07/12/2024] [Indexed: 07/19/2024] Open
Abstract
Although repetitive DNA forms much of the human genome, its study is challenging due to limitations in assembly and alignment of repetitive short-reads. We have deployed k-Seek, software that detects tandem repeats embedded in single reads, on 2,504 human genomes from the 1,000 Genomes Project to quantify the variation and abundance of simple satellites (repeat units <20 bp). We find that the ancestral monomer of Human Satellite 3 makes up the largest portion of simple satellite content in humans (mean of ∼8 Mb). We discovered ∼50,000 rare tandem repeats that are not detected in the T2T-CHM13v2.0 assembly, including undescribed variants of telomericand pericentromeric repeats. We find broad homogeneity of the most abundant repeats across populations, except for AG-rich repeats which are more abundant in African individuals. We also find cliques of highly similar AG- and AT-rich satellites that are interspersed and form higher-order structures that covary in copy number across individuals, likely through concerted amplification via unequal exchange. Finally, we use pericentromeric polymorphisms to estimate centromeric genetic relatedness between individuals and find a strong predictive relationship between centromeric lineages and pericentromeric simple satellite abundances. In particular, ancestral monomers of Human Satellite 2 and Human Satellite 3 abundances correlate with clusters of centromeric ancestry on chromosome 16 and chromosome 9, with some clusters structured by population. These results provide new descriptions of the population dynamics that underlie the evolution of simple satellites in humans.
Collapse
Affiliation(s)
- Iskander Said
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Daniel A Barbash
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Andrew G Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
2
|
Seifert BA, Reddi HV, Kang BE, Bean LJH, Shealy A, Rose NC. Myotonic dystrophy type 1 testing, 2024 revision: A technical standard of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2024; 26:101145. [PMID: 38836869 PMCID: PMC11298302 DOI: 10.1016/j.gim.2024.101145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 04/11/2024] [Indexed: 06/06/2024] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a form of muscular dystrophy causing progressive muscle loss and weakness. Although clinical features can manifest at any age, it is the most common form of muscular dystrophy with onset in adulthood. DM1 is an autosomal dominant condition, resulting from an unstable CTG expansion in the 3'-untranslated region of the myotonic dystrophy protein kinase (DMPK) gene. The age of onset and the severity of the phenotype are roughly correlated with the size of the CTG expansion. Multiple methodologies can be used to diagnose affected individuals with DM1, including polymerase chain reaction, Southern blot, and triplet repeat-primed polymerase chain reaction. Recently, triplet repeat interruptions have been described, which may affect clinical outcomes of a fully-variable allele in DMPK. This document supersedes the Technical Standards and Guidelines for Myotonic Dystrophy originally published in 2009 and reaffirmed in 2015. It is designed for genetic testing professionals who are already familiar with the disease and the methods of analysis.
Collapse
Affiliation(s)
- Bryce A Seifert
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Honey V Reddi
- Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, Milwaukee, WI
| | - Benjamin E Kang
- Department of Pathology and Pediatrics, University of Michigan Medical School, Ann Arbor, MI; Vanderbilt University Medical Center, Nashville, TN
| | | | - Amy Shealy
- Cleveland Clinic Center for Personalized Genetic Healthcare, Cleveland, OH
| | - Nancy C Rose
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT
| |
Collapse
|
3
|
Conte TC, Duran-Bishop G, Orfi Z, Mokhtari I, Deprez A, Côté I, Molina T, Kim TY, Tellier L, Roussel MP, Maggiorani D, Benabdallah B, Leclerc S, Feulner L, Pellerito O, Mathieu J, Andelfinger G, Gagnon C, Beauséjour C, McGraw S, Duchesne E, Dumont NA. Clearance of defective muscle stem cells by senolytics restores myogenesis in myotonic dystrophy type 1. Nat Commun 2023; 14:4033. [PMID: 37468473 PMCID: PMC10356779 DOI: 10.1038/s41467-023-39663-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 06/22/2023] [Indexed: 07/21/2023] Open
Abstract
Muscle stem cells, the engine of muscle repair, are affected in myotonic dystrophy type 1 (DM1); however, the underlying molecular mechanism and the impact on the disease severity are still elusive. Here, we show using patients' samples that muscle stem cells/myoblasts exhibit signs of cellular senescence in vitro and in situ. Single cell RNAseq uncovers a subset of senescent myoblasts expressing high levels of genes related to the senescence-associated secretory phenotype (SASP). We show that the levels of interleukin-6, a prominent SASP cytokine, in the serum of DM1 patients correlate with muscle weakness and functional capacity limitations. Drug screening revealed that the senolytic BCL-XL inhibitor (A1155463) can specifically remove senescent DM1 myoblasts by inducing their apoptosis. Clearance of senescent cells reduced the expression of SASP, which rescued the proliferation and differentiation capacity of DM1 myoblasts in vitro and enhanced their engraftment following transplantation in vivo. Altogether, this study identifies the pathogenic mechanism associated with muscle stem cell defects in DM1 and opens a therapeutic avenue that targets these defective cells to restore myogenesis.
Collapse
Affiliation(s)
- Talita C Conte
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Gilberto Duran-Bishop
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of obstetrics and gynecology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Zakaria Orfi
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Inès Mokhtari
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of Health Sciences, Université du Québec à Chicoutimi, Saguenay, QC, Canada
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
| | - Alyson Deprez
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Isabelle Côté
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
| | - Thomas Molina
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Tae-Yeon Kim
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of microbiology, infectiology and immunology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Lydia Tellier
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- School of rehabilitation, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Marie-Pier Roussel
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
- Department of Fundamental Sciences, Université du Québec à Chicoutimi, Saguenay, QC, Canada
| | - Damien Maggiorani
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | | | | | - Lara Feulner
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
| | | | - Jean Mathieu
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
- CHU Sherbrooke Research Center, and Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Gregor Andelfinger
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of Pediatrics, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Cynthia Gagnon
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada
- CHU Sherbrooke Research Center, and Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Christian Beauséjour
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Serge McGraw
- CHU Sainte-Justine Research Center, Montreal, QC, Canada
- Department of obstetrics and gynecology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Elise Duchesne
- Department of Health Sciences, Université du Québec à Chicoutimi, Saguenay, QC, Canada.
- Neuromuscular diseases interdisciplinary research group (GRIMN), Saguenay-Lac-St-Jean Integrated University Health and Social Services Center, Saguenay, QC, Canada.
| | - Nicolas A Dumont
- CHU Sainte-Justine Research Center, Montreal, QC, Canada.
- School of rehabilitation, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada.
| |
Collapse
|
4
|
Neault N, Ravel-Chapuis A, Baird SD, Lunde JA, Poirier M, Staykov E, Plaza-Diaz J, Medina G, Abadía-Molina F, Jasmin BJ, MacKenzie AE. Vorinostat Improves Myotonic Dystrophy Type 1 Splicing Abnormalities in DM1 Muscle Cell Lines and Skeletal Muscle from a DM1 Mouse Model. Int J Mol Sci 2023; 24:ijms24043794. [PMID: 36835205 PMCID: PMC9964082 DOI: 10.3390/ijms24043794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/08/2023] [Accepted: 02/11/2023] [Indexed: 02/16/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1), the most common form of adult muscular dystrophy, is caused by an abnormal expansion of CTG repeats in the 3' untranslated region of the dystrophia myotonica protein kinase (DMPK) gene. The expanded repeats of the DMPK mRNA form hairpin structures in vitro, which cause misregulation and/or sequestration of proteins including the splicing regulator muscleblind-like 1 (MBNL1). In turn, misregulation and sequestration of such proteins result in the aberrant alternative splicing of diverse mRNAs and underlie, at least in part, DM1 pathogenesis. It has been previously shown that disaggregating RNA foci repletes free MBNL1, rescues DM1 spliceopathy, and alleviates associated symptoms such as myotonia. Using an FDA-approved drug library, we have screened for a reduction of CUG foci in patient muscle cells and identified the HDAC inhibitor, vorinostat, as an inhibitor of foci formation; SERCA1 (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase) spliceopathy was also improved by vorinostat treatment. Vorinostat treatment in a mouse model of DM1 (human skeletal actin-long repeat; HSALR) improved several spliceopathies, reduced muscle central nucleation, and restored chloride channel levels at the sarcolemma. Our in vitro and in vivo evidence showing amelioration of several DM1 disease markers marks vorinostat as a promising novel DM1 therapy.
Collapse
Affiliation(s)
- Nafisa Neault
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 5B2, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- School of Pharmaceutical Sciences, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Stephen D. Baird
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 5B2, Canada
| | - John A. Lunde
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Mathieu Poirier
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 5B2, Canada
| | - Emiliyan Staykov
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 5B2, Canada
| | - Julio Plaza-Diaz
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 5B2, Canada
- Department of Biochemistry and Molecular Biology II, School of Pharmacy, University of Granada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria IBS.GRANADA, Complejo Hospitalario Universitario de Granada, 18014 Granada, Spain
| | - Gerardo Medina
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 5B2, Canada
| | - Francisco Abadía-Molina
- Institute of Nutrition and Food Technology “José Mataix”, Biomedical Research Center, University of Granada, Armilla, 18016 Granada, Spain
- Department of Cell Biology, School of Sciences, University of Granada, 18071 Granada, Spain
| | - Bernard J. Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Alex E. MacKenzie
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 5B2, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Eric Poulin Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Correspondence: ; Tel.: +1-613-737-2772
| |
Collapse
|
5
|
Stoodley J, Vallejo-Bedia F, Seone-Miraz D, Debasa-Mouce M, Wood MJA, Varela MA. Application of Antisense Conjugates for the Treatment of Myotonic Dystrophy Type 1. Int J Mol Sci 2023; 24:2697. [PMID: 36769018 PMCID: PMC9916419 DOI: 10.3390/ijms24032697] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 02/04/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is one of the most common muscular dystrophies and can be potentially treated with antisense therapy decreasing mutant DMPK, targeting miRNAs or their binding sites or via a blocking mechanism for MBNL1 displacement from the repeats. Unconjugated antisense molecules are able to correct the disease phenotype in mouse models, but they show poor muscle penetration upon systemic delivery in DM1 patients. In order to overcome this challenge, research has focused on the improvement of the therapeutic window and biodistribution of antisense therapy using bioconjugation to lipids, cell penetrating peptides or antibodies. Antisense conjugates are able to induce the long-lasting correction of DM1 pathology at both molecular and functional levels and also efficiently penetrate hard-to-reach tissues such as cardiac muscle. Delivery to the CNS at clinically relevant levels remains challenging and the use of alternative administration routes may be necessary to ameliorate some of the symptoms experienced by DM1 patients. With several antisense therapies currently in clinical trials, the outlook for achieving a clinically approved treatment for patients has never looked more promising.
Collapse
Affiliation(s)
- Jessica Stoodley
- Department of Paediatrics, Institute of Developmental and Regenerative Medicine (IDRM), University of Oxford, Roosevelt Dr, Oxford OX3 7TY, UK
- MDUK Oxford Neuromuscular Centre, Oxford OX3 7TY, UK
| | - Francisco Vallejo-Bedia
- Department of Paediatrics, Institute of Developmental and Regenerative Medicine (IDRM), University of Oxford, Roosevelt Dr, Oxford OX3 7TY, UK
- MDUK Oxford Neuromuscular Centre, Oxford OX3 7TY, UK
| | - David Seone-Miraz
- Department of Paediatrics, Institute of Developmental and Regenerative Medicine (IDRM), University of Oxford, Roosevelt Dr, Oxford OX3 7TY, UK
- MDUK Oxford Neuromuscular Centre, Oxford OX3 7TY, UK
| | - Manuel Debasa-Mouce
- Department of Paediatrics, Institute of Developmental and Regenerative Medicine (IDRM), University of Oxford, Roosevelt Dr, Oxford OX3 7TY, UK
- MDUK Oxford Neuromuscular Centre, Oxford OX3 7TY, UK
| | - Matthew J. A. Wood
- Department of Paediatrics, Institute of Developmental and Regenerative Medicine (IDRM), University of Oxford, Roosevelt Dr, Oxford OX3 7TY, UK
- MDUK Oxford Neuromuscular Centre, Oxford OX3 7TY, UK
| | - Miguel A. Varela
- Department of Paediatrics, Institute of Developmental and Regenerative Medicine (IDRM), University of Oxford, Roosevelt Dr, Oxford OX3 7TY, UK
- MDUK Oxford Neuromuscular Centre, Oxford OX3 7TY, UK
| |
Collapse
|
6
|
Abstract
PURPOSE OF REVIEW Myotonic dystrophy type 1 (DM1) and myotonic dystrophy type 2 (DM2) are genetic disorders affecting skeletal and smooth muscle, heart, brain, eyes, and other organs. The multisystem involvement and disease variability of myotonic dystrophy have presented challenges for clinical care and research. This article focuses on the diagnosis and management of the disease. In addition, recent advances in characterizing the diverse clinical manifestations and variability of the disease are discussed. RECENT FINDINGS Studies of the multisystem involvement of myotonic dystrophy, including the most lethal cardiac and respiratory manifestations and their molecular underpinnings, expand our understanding of the myotonic dystrophy phenotype. Advances have been made in understanding the molecular mechanisms of both types of myotonic dystrophy, providing opportunities for developing targeted therapeutics, some of which have entered clinical trials in DM1. SUMMARY Continued efforts focus on advancing our molecular and clinical understanding of DM1 and DM2. Accurately measuring and monitoring the diverse and variable clinical manifestations of myotonic dystrophy in clinic and in research is important to provide adequate care, prevent complications, and find treatments that improve symptoms and life quality.
Collapse
|
7
|
Intergenerational Influence of Gender and the DM1 Phenotype of the Transmitting Parent in Korean Myotonic Dystrophy Type 1. Genes (Basel) 2022; 13:genes13081465. [PMID: 36011377 PMCID: PMC9408469 DOI: 10.3390/genes13081465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/11/2022] [Accepted: 08/15/2022] [Indexed: 11/18/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is the most common autosomal-dominant disorder caused by the CTG repeat expansion of the DMPK, and it has been categorized into three phenotypes: mild, classic, and congenital DM1. Here, we reviewed the intergenerational influence of gender and phenotype of the transmitting parent on the occurrence of Korean DM1. A total of 44 parent–child pairs matched for the gender of the transmitting parent and the affected child and 29 parent–child pairs matched for the gender and DM1 phenotype of the transmitting parent were reviewed. The CTG repeat size of the DMPK in the affected child was found to be significantly greater when transmitted by a female parent to a female child (DM1-FF) (median, 1309 repeats; range, 400–2083) than when transmitted by a male parent to a male child (650; 160–1030; p = 0.038 and 0.048 using the Tukey HSD and the Bonferroni test) or by a male parent to a female child (480; 94–1140; p = 0.003). The difference in the CTG repeat size of the DMPK between the transmitting parent and the affected child was also lower when transmitted from a male parent with classic DM1 (−235; −280 to 0) compared to when it was transmitted from a female parent with mild DM1 (866; 612–905; p = 0.015 and 0.019) or from a female parent with classic DM1 (DM1-FC) (605; 10–1393; p = 0.005). This study highlights that gender and the DM1 phenotype of the transmitting parent had an impact on the CTG repeat size of the DMPK in the affected child, with greater increases being inherited from the DM1-FF or DM1-FC situations in Korean DM1.
Collapse
|
8
|
Ravel-Chapuis A, Duchesne E, Jasmin BJ. Pharmacological and exercise-induced activation of AMPK as emerging therapies for myotonic dystrophy type 1 patients. J Physiol 2022; 600:3249-3264. [PMID: 35695045 DOI: 10.1113/jp282725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/07/2022] [Indexed: 11/08/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystemic disorder with variable clinical features. Currently, there is no cure or effective treatment for DM1. The disease is caused by an expansion of CUG repeats in the 3' UTR of DMPK mRNAs. Mutant DMPK mRNAs accumulate in nuclei as RNA foci and trigger an imbalance in the level and localization of RNA-binding proteins causing the characteristic missplicing events that account for the varied DM1 symptoms, a disease mechanism referred to as RNA toxicity. In recent years, multiple signalling pathways have been identified as being aberrantly regulated in skeletal muscle in response to the CUG expansion, including AMPK, a sensor of energy status, as well as a master regulator of cellular energy homeostasis. Converging lines of evidence highlight the benefits of activating AMPK signalling pharmacologically on RNA toxicity, as well as on muscle histology and function, in preclinical DM1 models. Importantly, a clinical trial with metformin, an activator of AMPK, resulted in functional benefits in DM1 patients. In addition, exercise, a known AMPK activator, has shown promising effects on RNA toxicity and muscle function in DM1 mice. Finally, clinical trials involving moderate-intensity exercise also induced functional benefits for DM1 patients. Taken together, these studies clearly demonstrate the molecular, histological and functional benefits of AMPK activation and exercise-based interventions on the DM1 phenotype. Despite these advances, several key questions remain; in particular, the extent of the true implication of AMPK in the observed beneficial improvements, as well as how, mechanistically, activation of AMPK signalling improves the DM1 pathophysiology.
Collapse
Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Elise Duchesne
- Département des sciences de la santé, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada.,Groupe de Recherche Interdisciplinaire sur les Maladies Neuromusculaires (GRIMN), Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Hôpital de Jonquière, QC, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Eric Poulin Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
9
|
Barbé L, Finkbeiner S. Genetic and Epigenetic Interplay Define Disease Onset and Severity in Repeat Diseases. Front Aging Neurosci 2022; 14:750629. [PMID: 35592702 PMCID: PMC9110800 DOI: 10.3389/fnagi.2022.750629] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
Repeat diseases, such as fragile X syndrome, myotonic dystrophy, Friedreich ataxia, Huntington disease, spinocerebellar ataxias, and some forms of amyotrophic lateral sclerosis, are caused by repetitive DNA sequences that are expanded in affected individuals. The age at which an individual begins to experience symptoms, and the severity of disease, are partially determined by the size of the repeat. However, the epigenetic state of the area in and around the repeat also plays an important role in determining the age of disease onset and the rate of disease progression. Many repeat diseases share a common epigenetic pattern of increased methylation at CpG islands near the repeat region. CpG islands are CG-rich sequences that are tightly regulated by methylation and are often found at gene enhancer or insulator elements in the genome. Methylation of CpG islands can inhibit binding of the transcriptional regulator CTCF, resulting in a closed chromatin state and gene down regulation. The downregulation of these genes leads to some disease-specific symptoms. Additionally, a genetic and epigenetic interplay is suggested by an effect of methylation on repeat instability, a hallmark of large repeat expansions that leads to increasing disease severity in successive generations. In this review, we will discuss the common epigenetic patterns shared across repeat diseases, how the genetics and epigenetics interact, and how this could be involved in disease manifestation. We also discuss the currently available stem cell and mouse models, which frequently do not recapitulate epigenetic patterns observed in human disease, and propose alternative strategies to study the role of epigenetics in repeat diseases.
Collapse
Affiliation(s)
- Lise Barbé
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, United States
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
| | - Steve Finkbeiner
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, United States
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
- *Correspondence: Steve Finkbeiner,
| |
Collapse
|
10
|
Kong HE, Pollack BP. Cutaneous findings in myotonic dystrophy. JAAD Int 2022; 7:7-12. [PMID: 35243403 PMCID: PMC8867117 DOI: 10.1016/j.jdin.2021.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2021] [Indexed: 11/06/2022] Open
Abstract
Myotonic dystrophy types 1 and 2 are a group of complex genetic disorders resulting from the expansion of (CTG)n nucleotide repeats in the DMPK gene. In addition to the hallmark manifestations of myotonia and skeletal muscle atrophy, myotonic dystrophy also affects a myriad of other organs including the heart, lungs, as well as the skin. The most common cutaneous manifestations of myotonic dystrophy are early male frontal alopecia and adult-onset pilomatricomas. Myotonic dystrophy also increases the risk of developing malignant skin diseases such as basal cell carcinoma and melanoma. To aid in the diagnosis and treatment of myotonic dystrophy related skin conditions, it is important for the dermatologist to become cognizant of the common and rare cutaneous manifestations of this genetic disorder. We performed a PubMed search using the key terms “myotonic dystrophy” AND “cutaneous” OR “skin” OR “dermatologic” AND “manifestation” OR “finding.” The resulting publications were manually reviewed for additional relevant publications, and subsequent additional searches were performed as needed, especially regarding the molecular mechanisms of pathogenesis. In this review, we aim to provide an overview of myotonic dystrophy types 1 and 2 and summarize their cutaneous manifestations as well as potential mechanisms of pathogenesis.
Collapse
Affiliation(s)
- Ha Eun Kong
- Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia
| | - Brian P Pollack
- Atlanta VA Health System, Decatur, Georgia.,Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia.,Department of Pathology, Emory University School of Medicine, Atlanta, Georgia.,Winship Cancer Institute of Emory University School of Medicine, Atlanta, Georgia
| |
Collapse
|
11
|
De Serres-Bérard T, Pierre M, Chahine M, Puymirat J. Deciphering the mechanisms underlying brain alterations and cognitive impairment in congenital myotonic dystrophy. Neurobiol Dis 2021; 160:105532. [PMID: 34655747 DOI: 10.1016/j.nbd.2021.105532] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/24/2021] [Accepted: 10/11/2021] [Indexed: 12/13/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystemic and heterogeneous disorder caused by the expansion of CTG repeats in the 3' UTR of the myotonic dystrophy protein kinase (DMPK) gene. There is a congenital form (CDM1) of the disease characterized by severe hypotonia, respiratory insufficiency as well as developmental delays and intellectual disabilities. CDM1 infants manifest important brain structure abnormalities present from birth while, in contrast, older patients with adult-onset DM1 often present neurodegenerative features and milder progressive cognitive deficits. Promising therapies targeting central molecular mechanisms contributing to the symptoms of adult-onset DM1 are currently in development, but their relevance for treating cognitive impairment in CDM1, which seems to be a partially distinct neurodevelopmental disorder, remain to be elucidated. Here, we provide an update on the clinical presentation of CDM1 and review recent in vitro and in vivo models that have provided meaningful insights on its consequences in development, with a particular focus on the brain. We discuss how enhanced toxic gain-of-function of the mutated DMPK transcripts with larger CUG repeats and the resulting dysregulation of RNA-binding proteins may affect the developing cortex in utero. Because the methylation of CpG islets flanking the trinucleotide repeats has emerged as a strong biomarker of CDM1, we highlight the need to investigate the tissue-specific impacts of these chromatin modifications in the brain. Finally, we outline promising potential therapeutic treatments for CDM1 and propose future in vitro and in vivo models with great potential to shed light on this disease.
Collapse
Affiliation(s)
- Thiéry De Serres-Bérard
- LOEX, CHU de Québec-Université Laval Research Center, Quebec City, Canada; CERVO Brain Research Center, Institut universitaire en santé mentale de Québec, Quebec City, Canada
| | - Marion Pierre
- CERVO Brain Research Center, Institut universitaire en santé mentale de Québec, Quebec City, Canada
| | - Mohamed Chahine
- CERVO Brain Research Center, Institut universitaire en santé mentale de Québec, Quebec City, Canada; Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Canada.
| | - Jack Puymirat
- LOEX, CHU de Québec-Université Laval Research Center, Quebec City, Canada; Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Canada
| |
Collapse
|
12
|
Neault N, O’Reilly S, Baig AT, Plaza-Diaz J, Azimi M, Farooq F, Baird SD, MacKenzie A. High-throughput kinome-RNAi screen identifies protein kinase R activator (PACT) as a novel genetic modifier of CUG foci integrity in myotonic dystrophy type 1 (DM1). PLoS One 2021; 16:e0256276. [PMID: 34520479 PMCID: PMC8439471 DOI: 10.1371/journal.pone.0256276] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 08/03/2021] [Indexed: 11/24/2022] Open
Abstract
Myotonic Dystrophy Type 1 (DM1) is the most common form of adult muscular dystrophy (~1:8000). In DM1, expansion of CTG trinucleotide repeats in the 3' untranslated region of the dystrophia myotonica protein kinase (DMPK) gene results in DMPK mRNA hairpin structures which aggregate as insoluble ribonuclear foci and sequester several RNA-binding proteins. The resulting sequestration and misregulation of important splicing factors, such as muscleblind-like 1 (MBNL1), causes the aberrant expression of fetal transcripts for several genes that contribute to the disease phenotype. Previous work has shown that antisense oligonucleotide-mediated disaggregation of the intranuclear foci has the potential to reverse downstream anomalies. To explore whether the nuclear foci are, to some extent, controlled by cell signalling pathways, we have performed a screen using a small interfering RNA (siRNA) library targeting 518 protein kinases to look at kinomic modulation of foci integrity. RNA foci were visualized by in situ hybridization of a fluorescent-tagged (CAG)10 probe directed towards the expanded DMPK mRNA and the cross-sectional area and number of foci per nuclei were recorded. From our screen, we have identified PACT (protein kinase R (PKR) activator) as a novel modulator of foci integrity and have shown that PACT knockdown can both increase MBNL1 protein levels; however, these changes are not suffcient for significant correction of downstream spliceopathies.
Collapse
Affiliation(s)
- Nafisa Neault
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Sean O’Reilly
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Aiman Tariq Baig
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Julio Plaza-Diaz
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Mehrdad Azimi
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Faraz Farooq
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Stephen D. Baird
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Alex MacKenzie
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| |
Collapse
|
13
|
Morales F, Corrales E, Zhang B, Vásquez M, Santamaría-Ulloa C, Quesada H, Sirito M, Estecio MR, Monckton DG, Krahe R. Myotonic dystrophy type 1 (DM1) clinical sub-types and CTCF site methylation status flanking the CTG expansion are mutant allele length-dependent. Hum Mol Genet 2021; 31:262-274. [PMID: 34432028 DOI: 10.1093/hmg/ddab243] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/15/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a complex disease with a wide spectrum of symptoms. The exact relationship between mutant CTG repeat expansion size and clinical outcome remains unclear. DM1 congenital patients (CDM) inherit the largest expanded alleles, which are associated with abnormal and increased DNA methylation flanking the CTG repeat. However, DNA methylation at the DMPK locus remains understudied. Its relationship to DM1 clinical subtypes, expansion size and age-at-onset is not yet completely understood. Using pyrosequencing-based methylation analysis on 225 blood DNA samples from Costa Rican DM1 patients, we determined that the size of the estimated progenitor allele length (ePAL) is not only a good discriminator between CDM and non-CDM cases (with an estimated threshold at 653 CTG repeats), but also for all DM1 clinical subtypes. Secondly, increased methylation at both CTCF sites upstream and downstream of the expansion was almost exclusively present in CDM cases. Thirdly, levels of abnormal methylation were associated with clinical subtype, age and ePAL, with strong correlations between these variables. Fourthly, both ePAL and the intergenerational expansion size were significantly associated with methylation status. Finally, methylation status was associated with ePAL and maternal inheritance, with almost exclusively maternal transmission of CDM. In conclusion, increased DNA methylation at the CTCF sites flanking the DM1 expansion could be linked to ePAL, and both increased methylation and the ePAL could be considered biomarkers for the CDM phenotype.
Collapse
Affiliation(s)
- Fernando Morales
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Eyleen Corrales
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Baili Zhang
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA
| | - Melissa Vásquez
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Carolina Santamaría-Ulloa
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Hazel Quesada
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Mario Sirito
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA
| | - Marcos R Estecio
- Department of Epigenetics & Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA.,Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Ralf Krahe
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA.,Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA
| |
Collapse
|
14
|
Li K, Krueger SB, Zimmerman SC. A Novel Minor Groove Binder as a Potential Therapeutic Agent for Myotonic Dystrophy Type 1. ChemMedChem 2021; 16:2638-2644. [PMID: 34114350 DOI: 10.1002/cmdc.202100243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Indexed: 11/10/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystemic neuromuscular disorder that is inherited in an autosomal dominant manner. DM1 originates in a (CTG⋅CAG) repeat expansion in the 3'-UTR of the dystrophia myotonic protein kinase (DMPK) gene on chromosome 19. One of the transcripts, r(CUG)exp , is toxic in various ways. Herein we report a rationally designed small molecule with a thiazole peptidomimetic unit that can serve as a minor groove binder for the nucleic acid targets. This peptide unit linked to two triaminotriazine recognition units selectively binds to d(CTG)exp to inhibit the transcription process, and also targets r(CUG)exp selectively to improve representative DM1 pathological molecular features, including foci formation and pre-mRNA splicing defects in DM1 model cells. As such, it represents a new structure type that might serve as a lead compound for future structure-activity optimization.
Collapse
Affiliation(s)
- Ke Li
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, 61801, Urbana, IL, USA
| | - Sarah B Krueger
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, 61801, Urbana, IL, USA
| | - Steven C Zimmerman
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S Mathews Avenue, 61801, Urbana, IL, USA
| |
Collapse
|
15
|
Weskamp K, Olwin BB, Parker R. Post-Transcriptional Regulation in Skeletal Muscle Development, Repair, and Disease. Trends Mol Med 2020; 27:469-481. [PMID: 33384234 DOI: 10.1016/j.molmed.2020.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 12/14/2022]
Abstract
Skeletal muscle formation is a complex process that requires tight spatiotemporal control of key myogenic factors. Emerging evidence suggests that RNA processing is crucial for the regulation of these factors, and that multiple post-transcriptional regulatory pathways work dependently and independently of one another to enable precise control of transcripts throughout muscle development and repair. Moreover, disruption of these pathways is implicated in neuromuscular disease, and the recent development of RNA-mediated therapies shows enormous promise in the treatment of these disorders. We discuss the overlapping post-transcriptional regulatory pathways that mediate muscle development, how these pathways are disrupted in neuromuscular disorders, and advances in RNA-mediated therapies that present a novel approach to the treatment of these diseases.
Collapse
Affiliation(s)
- Kaitlin Weskamp
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.
| | - Bradley B Olwin
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| |
Collapse
|
16
|
Marsh S, Hanson B, Wood MJA, Varela MA, Roberts TC. Application of CRISPR-Cas9-Mediated Genome Editing for the Treatment of Myotonic Dystrophy Type 1. Mol Ther 2020; 28:2527-2539. [PMID: 33171139 PMCID: PMC7704741 DOI: 10.1016/j.ymthe.2020.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/03/2020] [Accepted: 10/08/2020] [Indexed: 12/15/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a debilitating multisystemic disorder, caused by expansion of a CTG microsatellite repeat in the 3' untranslated region of the DMPK (dystrophia myotonica protein kinase) gene. To date, novel therapeutic approaches have focused on transient suppression of the mutant, repeat-expanded RNA. However, recent developments in the field of genome editing have raised the exciting possibility of inducing permanent correction of the DM1 genetic defect. Specifically, repurposing of the prokaryotic CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 (CRISPR-associated protein 9) system has enabled programmable, site-specific, and multiplex genome editing. CRISPR-based strategies for the treatment of DM1 can be applied either directly to patients, or indirectly through the ex vivo modification of patient-derived cells, and they include excision of the repeat expansion, insertion of synthetic polyadenylation signals upstream of the repeat, steric interference with RNA polymerase II procession through the repeat leading to transcriptional downregulation of DMPK, and direct RNA targeting of the mutant RNA species. Potential obstacles to such therapies are discussed, including the major challenge of Cas9 and guide RNA transgene/ribonuclear protein delivery, off-target gene editing, vector genome insertion at cut sites, on-target unintended mutagenesis (e.g., repeat inversion), pre-existing immunity to Cas9 or AAV antigens, immunogenicity, and Cas9 persistence.
Collapse
Affiliation(s)
- Seren Marsh
- University of Oxford Medical School, Medical Sciences Division, University of Oxford, Oxford OX3 9DU, UK
| | - Britt Hanson
- Department of Physiology, Anatomy and Genetics, Oxford OX1 3QX, UK; Department of Paediatrics, University of Oxford, Oxford OX1 3QX, UK
| | - Matthew J A Wood
- Department of Paediatrics, University of Oxford, Oxford OX1 3QX, UK; MDUK Oxford Neuromuscular Centre, UK
| | - Miguel A Varela
- Department of Paediatrics, University of Oxford, Oxford OX1 3QX, UK
| | - Thomas C Roberts
- Department of Paediatrics, University of Oxford, Oxford OX1 3QX, UK; MDUK Oxford Neuromuscular Centre, UK.
| |
Collapse
|
17
|
Saito Y, Matsumura K, Kageyama M, Kato Y, Ohta E, Sumi K, Futatani T, Yoshida T. Impact of prematurity and the CTG repeat length on outcomes in congenital myotonic dystrophy. BMC Res Notes 2020; 13:350. [PMID: 32703309 PMCID: PMC7379817 DOI: 10.1186/s13104-020-05186-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 07/15/2020] [Indexed: 01/03/2023] Open
Abstract
Objective Patients with congenital myotonic dystrophy (CDM) tend to be born preterm. Although the CDM severity generally depends on the CTG repeat length, prematurity may also affect the prognosis in patients with CDM. Given that preterm birth is expected to increase the risk of CDM in newborns, we investigated the outcomes of newborns with CDM according to gestational age to assess prematurity and the CTG repeat length for predicting prognosis. Results We assessed the outcomes of 54 infants with CDM using data collected from our hospitals and previously published studies. The patients were divided into mild and severe groups based on clinical outcomes. Logistic regression analysis was performed to estimate odds ratios (ORs) for CDM prognosis according to gestational age and the CTG repeat length and to construct a predictive model. Logistic regression analysis showed both the CTG repeat and gestational age were significantly associated with severe outcomes in patients with CDM (OR: 32.27, 95% CI 3.45–300.7; p = 0.002 and OR: 0.73, 95% CI 0.58–0.93; p = 0.0094, respectively). This predictive model for CDM prognosis exhibited good sensitivity (63%) and specificity (86%). Both prematurity and the CTG repeat length were significantly associated with the CDM severity.
Collapse
Affiliation(s)
- Yu Saito
- Division of Neonatology, Maternal and Perinatal Center, Toyama University Hospital, Toyama, Japan
| | - Kenta Matsumura
- Toyama Regional Center for Japan Environment and Children's Study, University of Toyama, Toyama, Japan
| | - Misao Kageyama
- Department of Neonatology, OKAYAMA Medical Center, Okayama, Japan
| | - Yuichi Kato
- Department of Neonatology, Anjo Kosei Hospital, Aichi, Japan
| | - Eiji Ohta
- Department of Pediatrics, Fukuoka University, Fukuoka, Japan
| | - Kiyoaki Sumi
- Department of Pediatrics, Aizenbashi Hospital, Osaka, Japan
| | - Takeshi Futatani
- Department of Pediatrics, Toyama Prefectural Central Hospital, Toyama, Japan
| | - Taketoshi Yoshida
- Division of Neonatology, Maternal and Perinatal Center, Toyama University Hospital, Toyama, Japan.
| |
Collapse
|
18
|
Ikeda M, Taniguchi-Ikeda M, Kato T, Shinkai Y, Tanaka S, Hagiwara H, Sasaki N, Masaki T, Matsumura K, Sonoo M, Kurahashi H, Saito F. Unexpected Mutations by CRISPR-Cas9 CTG Repeat Excision in Myotonic Dystrophy and Use of CRISPR Interference as an Alternative Approach. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 18:131-144. [PMID: 32637445 PMCID: PMC7321784 DOI: 10.1016/j.omtm.2020.05.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 05/20/2020] [Indexed: 12/18/2022]
Abstract
Myotonic dystrophy type 1 is the most common type of adult-onset muscular dystrophy. This is an autosomal dominant disorder and caused by the expansion of the CTG repeat in the 3′ untranslated region of the dystrophia myotonica protein kinase (DMPK) gene. Messenger RNAs containing these expanded repeats form aggregates as nuclear RNA foci. Then, RNA binding proteins, including muscleblind-like 1, are sequestered to the RNA foci, leading to systemic abnormal RNA splicing. In this study, we used CRISPR-Cas9 genome editing to excise this CTG repeat. Dual cleavage at the 5′ and 3′ regions of the repeat using a conventional Cas9 nuclease and a double nicking with Cas9 nickase successfully excised the CTG repeat. Subsequently, the formation of the RNA foci was markedly reduced in patient-derived fibroblasts. However, contrary to expectations, a considerable amount of off-target digestions and on-target genomic rearrangements were observed using high-throughput genome-wide translocation sequencing. Finally, the suppression of DMPK transcripts using CRISPR interference significantly decreased the intensity of RNA foci. Our results indicate that close attention should be paid to the unintended mutations when double-strand breaks are generated by CRISPR-Cas9 for therapeutic purposes. Alternative approaches independent of double-strand breaks, including CRISPR interference, may be considered.
Collapse
Affiliation(s)
- Miki Ikeda
- Department of Neurology, School of Medicine, Teikyo University, Tokyo 1738606, Japan
| | - Mariko Taniguchi-Ikeda
- Department of Clinical Genetics, Fujita Health University Hospital, Aichi 4701192, Japan.,Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Aichi 4701192, Japan
| | - Takema Kato
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Aichi 4701192, Japan
| | - Yasuko Shinkai
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Aichi 4701192, Japan
| | - Sonoko Tanaka
- Department of Neurology, School of Medicine, Teikyo University, Tokyo 1738606, Japan
| | - Hiroki Hagiwara
- Department of Medical Science, Teikyo University of Science, Uenohara Campus, Yamanashi 4090193, Japan
| | - Naomichi Sasaki
- Department of Medical Science, Teikyo University of Science, Senju Campus, Tokyo 1200045, Japan
| | - Toshihiro Masaki
- Department of Medical Science, Teikyo University of Science, Senju Campus, Tokyo 1200045, Japan
| | - Kiichiro Matsumura
- Department of Neurology, School of Medicine, Teikyo University, Tokyo 1738606, Japan
| | - Masahiro Sonoo
- Department of Neurology, School of Medicine, Teikyo University, Tokyo 1738606, Japan
| | - Hiroki Kurahashi
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Aichi 4701192, Japan
| | - Fumiaki Saito
- Department of Neurology, School of Medicine, Teikyo University, Tokyo 1738606, Japan
| |
Collapse
|
19
|
Kurauchi G, Endo M, Odaira K, Ono R, Koseki A, Goto M, Sato Y, Kon S, Watanabe N, Sugawara N, Kimura E, Takada H. Caregiver Burden and Related Factors Among Caregivers of Patients with Myotonic Dystrophy Type 1. J Neuromuscul Dis 2020; 6:527-536. [PMID: 31640106 DOI: 10.3233/jnd-190386] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Multi-systemic symptoms of varying severity in myotonic dystrophy type 1 (DM1) may pose difficulties in caregiving. However, the factors which affect their care burden are yet to be sufficiently understood. OBJECTIVE We investigated care burden and its correlates among caregivers of patients with DM1. METHODS General demographic information was obtained from patients with DM1, as well as Barthel index (ADL), body mass index, and genetic information. Patients completed SF-36v2 (health-related quality of life), CES-D (depressive symptoms), and ESS (daytime sleepiness) questionnaires. Caregivers reported their perception of patient's status through these questionnaires, and completed Zarit Caregiver Burden Interview (ZBI). Correlation analysis of these variables were performed, and regression analysis was utilized to assess the relationship between caregiver burden and other variables. RESULTS Forty-three patient-caregiver dyads participated. Mean ZBI score was 20.7±17.4, and 32.6% reported a significant care burden. ZBI correlated with caregiver-reported CES-D, but not with patient-reported CES-D. Both patient-reported and caregiver-reported physical QoL of patients correlated with patient ADL. Multiple regression analysis revealed that the combination of caregiver-reported CES-D, caregiver-reported mental QoL, and genetic characteristics predicted caregiver burden. CONCLUSIONS Caregiver burden was felt although patients were relatively well-functioning. Patients' and caregivers' assessment of patients' physical condition were similar. However, they did not agree on the evaluation of the patients' psychological state. Cognitive characteristic of the patients and the caregivers' perception of the patients' state may have affected the results. Future DM1 care strategies need to work on improvement of patient-caregiver communication and provide support for the caregiver's psychological health.
Collapse
Affiliation(s)
- Go Kurauchi
- Department of Rehabilitation, National Hospital Organization, Aomori Hospital, Megasawa-Hirano, Namioka, Aomori, Japan
| | - Makiko Endo
- Clinical Research Unit, National Center Hospital, National Center of Neurology and Psychiatry, Ogawahigashi-cho, Kodaira, Tokyo, Japan
| | - Kaori Odaira
- Regional Medical Liaison Office, National Hospital Organization, Aomori Hospital, Megasawa-Hirano, Namioka, Aomori, Japan
| | - Ryohei Ono
- Section for Development and Disability Training, National Hospital Organization, Aomori Hospital, Megasawa-Hirano, Namioka, Aomori, Japan
| | - Atsushi Koseki
- Section for Development and Disability Training, National Hospital Organization, Hanamaki Hospital, Suwa, Hanamaki, Iwate, Japan
| | - Momoko Goto
- Section for Development and Disability Training, National Hospital Organization, Aomori Hospital, Megasawa-Hirano, Namioka, Aomori, Japan
| | - Yumi Sato
- Department of Rehabilitation, National Hospital Organization, Aomori Hospital, Megasawa-Hirano, Namioka, Aomori, Japan
| | - Seiko Kon
- Department of Neurology, National Hospital Organization, Aomori Hospital, Megasawa-Hirano, Namioka, Aomori, Japan
| | - Norio Watanabe
- School of Public Health, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, Japan
| | - Norio Sugawara
- Department of Psychiatry, Dokkyo Medical University, Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi, Japan
| | - En Kimura
- Department of Clinical Research Support, Translational Medical Center, National Center of Neurology and Psychiatry, Ogawahigashi-cho, Kodaira, Tokyo, Japan
| | - Hiroto Takada
- Department of Neurology, National Hospital Organization, Aomori Hospital, Megasawa-Hirano, Namioka, Aomori, Japan
| |
Collapse
|
20
|
Ballester-Lopez A, Koehorst E, Almendrote M, Martínez-Piñeiro A, Lucente G, Linares-Pardo I, Núñez-Manchón J, Guanyabens N, Cano A, Lucia A, Overend G, Cumming SA, Monckton DG, Casadevall T, Isern I, Sánchez-Ojanguren J, Planas A, Rodríguez-Palmero A, Monlleó-Neila L, Pintos-Morell G, Ramos-Fransi A, Coll-Cantí J, Nogales-Gadea G. A DM1 family with interruptions associated with atypical symptoms and late onset but not with a milder phenotype. Hum Mutat 2019; 41:420-431. [PMID: 31608518 DOI: 10.1002/humu.23932] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 09/18/2019] [Accepted: 10/06/2019] [Indexed: 12/16/2022]
Abstract
Carriage of interruptions in CTG repeats of the myotonic dystrophy protein kinase gene has been associated with a broad spectrum of myotonic dystrophy type 1 (DM1) phenotypes, mostly mild. However, the data available on interrupted DM1 patients and their phenotype are scarce. We studied 49 Spanish DM1 patients, whose clinical phenotype was evaluated in depth. Blood DNA was obtained and analyzed through triplet-primed polymerase chain reaction (PCR), long PCR-Southern blot, small pool PCR, AciI digestion, and sequencing. Five patients of our registry (10%), belonging to the same family, carried CCG interruptions at the 3'-end of the CTG expansion. Some of them presented atypical traits such as very late onset of symptoms ( > 50 years) and a severe axial and proximal weakness requiring walking assistance. They also showed classic DM1 symptoms including cardiac and respiratory dysfunction, which were severe in some of them. Sizes and interrupted allele patterns were determined, and we found a contraction and an expansion in two intergenerational transmissions. Our study contributes to the observation that DM1 patients carrying interruptions present with atypical clinical features that can make DM1 diagnosis difficult, with a later than expected age of onset and a previously unreported aging-related severe disease manifestation.
Collapse
Affiliation(s)
- Alfonsina Ballester-Lopez
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Emma Koehorst
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Miriam Almendrote
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Alicia Martínez-Piñeiro
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Giuseppe Lucente
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Ian Linares-Pardo
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Judit Núñez-Manchón
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Nicolau Guanyabens
- Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Antoni Cano
- Neurology Unit, Neuroscience Department, Hospital de Mataró, Barcelona, Spain
| | - Alejandro Lucia
- Universidad Europea (Faculty of Sport Sciences), Madrid, Spain.,Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain
| | - Gayle Overend
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Sarah A Cumming
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Teresa Casadevall
- Neurology Service, Hospital Comarcal Sant Jaume de Calella, Barcelona, Spain
| | - Irina Isern
- Unitat de Neurologia, Hospital de l'Esperit Sant, Barcelona, Spain
| | | | - Albert Planas
- Servei de medicina interna, Secció de neurologia, Hospital Municipal de Badalona, Barcelona, Spain
| | - Agustí Rodríguez-Palmero
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuropediatric Unit, Pediatric Service, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Laura Monlleó-Neila
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuropediatric Unit, Pediatric Service, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Guillem Pintos-Morell
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Division of Rare Diseases, University Hospital Vall d'Hebron, Barcelona, Spain
| | - Alba Ramos-Fransi
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Jaume Coll-Cantí
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Neuromuscular Pathology Unit, Neurology Service, Neuroscience Department, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain
| | - Gisela Nogales-Gadea
- Neuromuscular and Neuropediatric Research Group, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
21
|
|
22
|
Wahbi K, Porcher R, Laforêt P, Fayssoil A, Bécane HM, Lazarus A, Sochala M, Stojkovic T, Béhin A, Leonard-Louis S, Arnaud P, Furling D, Probst V, Babuty D, Pellieux S, Clementy N, Bassez G, Péréon Y, Eymard B, Duboc D. Development and Validation of a New Scoring System to Predict Survival in Patients With Myotonic Dystrophy Type 1. JAMA Neurol 2019; 75:573-581. [PMID: 29404559 DOI: 10.1001/jamaneurol.2017.4778] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Life expectancy is greatly shortened in patients presenting with myotonic dystrophy type 1 (DM1), the most common neuromuscular disease. A reliable prediction of survival in patients with DM1 is critically important to plan personalized health supervision. Objective To develop and validate a prognostic score to predict 10-year survival in patients with DM1. Design, Setting, and Participants In this longitudinal cohort study, between January 2000 and November 2014, we enrolled 1296 adults referred to 4 tertiary neuromuscular centers in France for management of genetically proven DM1, including 1066 patients in the derivation cohort and 230 in the validation cohort. Data were analyzed from December 2016 to March 2017. Main Outcomes and Measures Factors associated with survival by multiple variable Cox modeling, including 95% confidence intervals, and development of a predictive score validated internally and externally. Mean values are reported with their standard deviations. Results Of the 1296 included patients, 670 (51.7%) were women, and the mean (SD) age was 39.8 (13.7) years. Among the 1066 patients (82.3%) in the derivation cohort, 241 (22.6%) died over a median (interquartile range) follow-up of 11.7 (7.7-14.3) years. Age, diabetes, need for support when walking, heart rate, systolic blood pressure, first-degree atrioventricular block, bundle-branch block, and lung vital capacity were associated with death. Simplified score points were attributed to each predictor, and adding these points yielded scores between 0 and 20, with 0 indicating the lowest and 20 the highest risk of death. The 10-year survival rate was 96.6% (95% CI, 94.4-98.9) in the group with 0 to 4 points, 92.2% (95% CI, 88.8-95.6) in the group with 5 to 7 points, 80.7% (95% CI, 75.4-86.1) in the group with 8 to 10 points, 57.9% (95% CI, 49.2-66.6) in the group with 11 to 13 points, and 19.4% (95% CI, 8.6-30.1) in the group with 14 points or more. In 230 patients (17.7%) included in the validation cohort, the 10-year survival rates for the groups with 0 to 4, 5 to 7, 8 to 10, 11 to 13, and 14 points or more were 99.3% (95% CI, 95.0-100), 80.6% (95% CI, 67.1-96.7), 79.3% (95% CI, 66.2-95.1), 43.2% (95% CI, 28.2-66.1), and 21.6% (95% CI, 10.0-46.8), respectively. The calibration curves did not deviate from the reference line. The C index was 0.753 (95% CI, 0.722-0.785) in the derivation cohort and 0.806 (95% CI, 0.758-0.855) in the validation cohort. Conclusions and Relevance The DM1 prognostic score is associated with long-term survival.
Collapse
Affiliation(s)
- Karim Wahbi
- Cardiology Department, Cochin Hospital, Filière Neuromusculaire, Paris-Descartes University, Sorbonne Paris Cité University, Assistance Publique-Hôpitaux de Paris, Paris, France.,Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France.,Thérapie des Maladies du Muscle Strié, Institut de Myologie, INSERM UMRS 974, Paris, France
| | - Raphaël Porcher
- Assistance Publique-Hôpitaux de Paris, Hôtel-Dieu, Centre d'Epidémiologie Clinique, Paris, France.,Centre de Recherche Épidémiologie et Statistique Sorbonne Paris Cité, INSERM U1153, Paris, France.,Paris Descartes University, Sorbonne Paris Cité, Paris, France
| | - Pascal Laforêt
- Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France
| | - Abdallah Fayssoil
- Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France
| | - Henri Marc Bécane
- Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France
| | - Arnaud Lazarus
- InParys Clinical Research Group, Clinique Ambroise Paré, Neuilly sur Seine, France
| | - Maximilien Sochala
- Cardiology Department, Cochin Hospital, Filière Neuromusculaire, Paris-Descartes University, Sorbonne Paris Cité University, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Tanya Stojkovic
- Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France
| | - Anthony Béhin
- Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France
| | - Sarah Leonard-Louis
- Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France
| | - Pauline Arnaud
- Département de Génétique, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Denis Furling
- Paris-Sorbonne Université, UPMC, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Centre de Recherches en Myologie, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Vincent Probst
- L'Unite de Recherche de l'Institut du Thorax, Université de Nantes, INSERM UMR 1087, Nantes, France.,Institut du Thorax, Centre Hospitalier Universitaire de Nantes, Centre d'Investigation Clinique, Centre de Référence pour la Prise en Charge des Maladies Rythmiques Héréditaires de Nantes, Nantes, France
| | - Dominique Babuty
- Cardiology Department, Université François Rabelais, Centre Hospitalier Régional Universitaire de Tours, Tours, France
| | - Sybille Pellieux
- Functional Readaptation Department, Université François Rabelais, Centre Hospitalier Régional Universitaire de Tours, Tours, France
| | - Nicolas Clementy
- Cardiology Department, Université François Rabelais, Centre Hospitalier Régional Universitaire de Tours, Tours, France
| | - Guillaume Bassez
- Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France
| | - Yann Péréon
- Centre de Référence des Maladies Neuromusculaires Rares Nantes-Angers, Filière Neuromusculaire, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Bruno Eymard
- Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France
| | - Denis Duboc
- Cardiology Department, Cochin Hospital, Filière Neuromusculaire, Paris-Descartes University, Sorbonne Paris Cité University, Assistance Publique-Hôpitaux de Paris, Paris, France.,Neurology Department, Centre de Référence de Pathologie Neuromusculaire Paris-Est, Myology Institute, Filière Neuromusculaire, Pitié-Salpêtrière Hospital, Paris, France.,Thérapie des Maladies du Muscle Strié, Institut de Myologie, INSERM UMRS 974, Paris, France
| |
Collapse
|
23
|
Lanni S, Pearson CE. Molecular genetics of congenital myotonic dystrophy. Neurobiol Dis 2019; 132:104533. [PMID: 31326502 DOI: 10.1016/j.nbd.2019.104533] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/29/2019] [Accepted: 07/11/2019] [Indexed: 12/26/2022] Open
Abstract
Myotonic Dystrophy type 1 (DM1) is a neuromuscular disease showing strong genetic anticipation, and is caused by the expansion of a CTG repeat tract in the 3'-UTR of the DMPK gene. Congenital Myotonic Dystrophy (CDM1) represents the most severe form of the disease, with prenatal onset, symptoms distinct from adult onset DM1, and a high rate of perinatal mortality. CDM1 is usually associated with very large CTG expansions, but this correlation is not absolute and cannot explain the distinct clinical features and the strong bias for maternal transmission. This review focuses upon the molecular and epigenetic factors that modulate disease severity and might be responsible for CDM1. Changes in the epigenetic status of the DM1 locus and in gene expression have recently been observed. Increasing evidence supports a role of a CTCF binding motif as a cis-element, upstream of the DMPK CTG tract, whereby CpG methylation of this site regulates the interaction of the insulator protein CTCF as a modulating trans-factor responsible for the inheritance and expression of CDM1.
Collapse
Affiliation(s)
- Stella Lanni
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto M5G 0A4, Ontario, Canada
| | - Christopher E Pearson
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto M5G 0A4, Ontario, Canada; University of Toronto, Program of Molecular Genetics, Canada.
| |
Collapse
|
24
|
Hale MA, Johnson NE, Berglund JA. Repeat-associated RNA structure and aberrant splicing. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194405. [PMID: 31323433 DOI: 10.1016/j.bbagrm.2019.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 12/13/2022]
Abstract
Over 30 hereditary disorders attributed to the expansion of microsatellite repeats have been identified. Despite variant nucleotide content, number of consecutive repeats, and different locations in the genome, many of these diseases have pathogenic RNA gain-of-function mechanisms. The repeat-containing RNAs can form structures in vitro predicted to contribute to the disease through assembly of intracellular RNA aggregates termed foci. The expanded repeat RNAs within these foci sequester RNA binding proteins (RBPs) with important roles in the regulation of RNA metabolism, most notably alternative splicing (AS). These deleterious interactions lead to downstream alterations in transcriptome-wide AS directly linked with disease symptoms. This review summarizes existing knowledge about the association between the repeat RNA structures and RBPs as well as the resulting aberrant AS patterns, specifically in the context of myotonic dystrophy. The connection between toxic, structured RNAs and dysregulation of AS in other repeat expansion diseases is also discussed. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
Collapse
Affiliation(s)
- Melissa A Hale
- Department of Neurology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Nicholas E Johnson
- Department of Neurology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - J Andrew Berglund
- The RNA Institute, Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA.
| |
Collapse
|
25
|
Sznajder ŁJ, Swanson MS. Short Tandem Repeat Expansions and RNA-Mediated Pathogenesis in Myotonic Dystrophy. Int J Mol Sci 2019; 20:ijms20133365. [PMID: 31323950 PMCID: PMC6651174 DOI: 10.3390/ijms20133365] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 06/27/2019] [Accepted: 07/08/2019] [Indexed: 12/23/2022] Open
Abstract
Short tandem repeat (STR) or microsatellite, expansions underlie more than 50 hereditary neurological, neuromuscular and other diseases, including myotonic dystrophy types 1 (DM1) and 2 (DM2). Current disease models for DM1 and DM2 propose a common pathomechanism, whereby the transcription of mutant DMPK (DM1) and CNBP (DM2) genes results in the synthesis of CUG and CCUG repeat expansion (CUGexp, CCUGexp) RNAs, respectively. These CUGexp and CCUGexp RNAs are toxic since they promote the assembly of ribonucleoprotein (RNP) complexes or RNA foci, leading to sequestration of Muscleblind-like (MBNL) proteins in the nucleus and global dysregulation of the processing, localization and stability of MBNL target RNAs. STR expansion RNAs also form phase-separated gel-like droplets both in vitro and in transiently transfected cells, implicating RNA-RNA multivalent interactions as drivers of RNA foci formation. Importantly, the nucleation and growth of these nuclear foci and transcript misprocessing are reversible processes and thus amenable to therapeutic intervention. In this review, we provide an overview of potential DM1 and DM2 pathomechanisms, followed by a discussion of MBNL functions in RNA processing and how multivalent interactions between expanded STR RNAs and RNA-binding proteins (RBPs) promote RNA foci assembly.
Collapse
Affiliation(s)
- Łukasz J Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA.
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| |
Collapse
|
26
|
Rodriguez CM, Todd PK. New pathologic mechanisms in nucleotide repeat expansion disorders. Neurobiol Dis 2019; 130:104515. [PMID: 31229686 DOI: 10.1016/j.nbd.2019.104515] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/07/2019] [Accepted: 06/19/2019] [Indexed: 12/14/2022] Open
Abstract
Tandem microsatellite repeats are common throughout the human genome and intrinsically unstable, exhibiting expansions and contractions both somatically and across generations. Instability in a small subset of these repeats are currently linked to human disease, although recent findings suggest more disease-causing repeats await discovery. These nucleotide repeat expansion disorders (NREDs) primarily affect the nervous system and commonly lead to neurodegeneration through toxic protein gain-of-function, protein loss-of-function, and toxic RNA gain-of-function mechanisms. However, the lines between these categories have blurred with recent findings of unconventional Repeat Associated Non-AUG (RAN) translation from putatively non-coding regions of the genome. Here we review two emerging topics in NREDs: 1) The mechanisms by which RAN translation occurs and its role in disease pathogenesis and 2) How nucleotide repeats as RNA and translated proteins influence liquid-liquid phase separation, membraneless organelle dynamics, and nucleocytoplasmic transport. We examine these topics with a particular eye on two repeats: the CGG repeat expansion responsible for Fragile X syndrome and Fragile X-associated Tremor Ataxia Syndrome (FXTAS) and the intronic GGGGCC repeat expansion in C9orf72, the most common inherited cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Our thesis is that these emerging disease mechanisms can inform a broader understanding of the native roles of microsatellites in cellular function and that aberrations in these native processes provide clues to novel therapeutic strategies for these currently untreatable disorders.
Collapse
Affiliation(s)
- C M Rodriguez
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA; Department of Genetics, Stanford University, Stanford, CA, USA
| | - P K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA; VA Ann Arbor Healthcare System, Ann Arbor, MI, USA.
| |
Collapse
|
27
|
Ravel-Chapuis A, Al-Rewashdy A, Bélanger G, Jasmin BJ. Pharmacological and physiological activation of AMPK improves the spliceopathy in DM1 mouse muscles. Hum Mol Genet 2019; 27:3361-3376. [PMID: 29982462 DOI: 10.1093/hmg/ddy245] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/28/2018] [Indexed: 12/26/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a debilitating multisystemic disorder caused by a triplet repeat expansion in the 3' untranslated region of dystrophia myotonica protein kinase mRNAs. Mutant mRNAs accumulate in the nucleus of affected cells and misregulate RNA-binding proteins, thereby promoting characteristic missplicing events. However, little is known about the signaling pathways that may be affected in DM1. Here, we investigated the status of activated protein kinase (AMPK) signaling in DM1 skeletal muscle and found that the AMPK pathway is markedly repressed in a DM1 mouse model (human skeletal actin-long repeat, HSALR) and patient-derived DM1 myoblasts. Chronic pharmacological activation of AMPK signaling in DM1 mice with 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) has multiple beneficial effects on the DM1 phenotype. Indeed, a 6-week AICAR treatment of DM1 mice promoted expression of a slower, more oxidative phenotype, improved muscle histology and corrected several events associated with RNA toxicity. Importantly, AICAR also had a dose-dependent positive effect on the spliceopathy in patient-derived DM1 myoblasts. In separate experiments, we also show that chronic treatment of DM1 mice with resveratrol as well as voluntary wheel running also rescued missplicing events in muscle. Collectively, our findings demonstrate the therapeutic potential of chronic AMPK stimulation both physiologically and pharmacologically for DM1 patients.
Collapse
Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Ali Al-Rewashdy
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Guy Bélanger
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
28
|
Huy Le B, Nguyen VT, Seo YJ. Site-specific incorporation of multiple units of functional nucleotides into DNA using a step-wise approach with polymerase and its application to monitoring DNA structural changes. Chem Commun (Camb) 2019; 55:2158-2161. [PMID: 30675606 DOI: 10.1039/c8cc09444f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have developed a new method, a step-wise approach with polymerase, for site-specific incorporation of multiple units of functional nucleotides into DNA to form hairpin secondary structures. The fluorescence of the resulting DNA incorporating the functional nucleotides varied upon transitioning from single-strand to hairpin and duplex structures.
Collapse
Affiliation(s)
- Binh Huy Le
- Department of Bioactive Material Sciences, Chonbuk National University, South Korea
| | | | | |
Collapse
|
29
|
Endo M, Odaira K, Ono R, Kurauchi G, Koseki A, Goto M, Sato Y, Kon S, Watanabe N, Sugawara N, Takada H, Kimura E. Health-related quality of life and its correlates in Japanese patients with myotonic dystrophy type 1. Neuropsychiatr Dis Treat 2019; 15:219-226. [PMID: 30679907 PMCID: PMC6338121 DOI: 10.2147/ndt.s187607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PURPOSE Myotonic dystrophy type 1 (DM1) is a common form of muscular dystrophy that presents with a variety of symptoms that can affect patients' quality of life (QoL). Despite the importance of clarifying patients' subjective experience in both physical and psychosocial aspects for improved symptom management, there is lack of evidence concerning QoL of patients with DM1 in Japan. PATIENTS AND METHODS A cross-sectional study was performed with 51 DM1 patients who completed questionnaires that measured health-related QoL (HRQoL), depression, and daytime sleepiness. Activities of daily living, body mass index (BMI), and genetic information were also collected, together with general demographic information. Correlation analyses using these variables were performed. Furthermore, regression analysis was utilized to assess the relationship that HRQoL, depression, and daytime sleepiness scores have with other variables. RESULTS Physical component summary (PCS) score was affected by the disease more than the mental component summary (MCS) score among study participants. Moderate correlation was observed between PCS and depression, PCS and Barthel index, and depression and daytime sleepiness. Regression analysis revealed that age, sex, cytosine-thymine-guanine repeats, and BMI did not predict the aforementioned dependent variables. CONCLUSION DM1 symptoms influenced physical component scores more than mental component scores, although the state of physical wellness seemed to affect patients' mood. Explaining the QoL of these patients only using biologic and genetic characteristics was not sufficient. We conclude that social and psychological aspects of these patients' lives and the nature of adjustments made by patients due to DM1 to require further examination in order to improve the standard of care.
Collapse
Affiliation(s)
- Makiko Endo
- Clinical Research Unit, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8551, Japan,
| | - Kaori Odaira
- Regional Medical Liaison Office, National Hospital Organization, Aomori Hospital, Namioka, Aomori 038-1331, Japan
| | - Ryohei Ono
- Section for Development and Disability Training, National Hospital Organization, Aomori Hospital, Namioka, Aomori 038-1331, Japan
| | - Go Kurauchi
- Department of Rehabilitation, National Hospital Organization, Aomori Hospital, Namioka, Aomori 038-1331, Japan
| | - Atsushi Koseki
- Section for Development and Disability Training, National Hospital Organization, Hanamaki Hospital, Hanamaki, Iwate 025-0033, Japan
| | - Momoko Goto
- Section for Development and Disability Training, National Hospital Organization, Aomori Hospital, Namioka, Aomori 038-1331, Japan
| | - Yumi Sato
- Department of Rehabilitation, National Hospital Organization, Aomori Hospital, Namioka, Aomori 038-1331, Japan
| | - Seiko Kon
- Department of Neurology, National Hospital Organization, Aomori Hospital, Namioka, Aomori 038-1331, Japan
| | - Norio Watanabe
- School of Public Health, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Norio Sugawara
- Department of Clinical Epidemiology, Translational Medical Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8551, Japan
| | - Hiroto Takada
- Department of Neurology, National Hospital Organization, Aomori Hospital, Namioka, Aomori 038-1331, Japan
| | - En Kimura
- Department of Clinical Research Support, Translational Medical Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8551, Japan
| |
Collapse
|
30
|
RNA-mediated therapies in myotonic dystrophy. Drug Discov Today 2018; 23:2013-2022. [PMID: 30086404 DOI: 10.1016/j.drudis.2018.08.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/25/2018] [Accepted: 08/01/2018] [Indexed: 12/29/2022]
Abstract
Myotonic dystrophy 1 (DM1) is a multisystemic neuromuscular disease caused by a dominantly inherited 'CTG' repeat expansion in the gene encoding DM Protein Kinase (DMPK). The repeats are transcribed into mRNA, which forms hairpins and binds with high affinity to the Muscleblind-like (MBNL) family of proteins, sequestering them from their normal function. The loss of function of MBNL proteins causes numerous downstream effects, primarily the appearance of nuclear foci, mis-splicing, and ultimately myotonia and other clinical symptoms. Antisense and other RNA-mediated technologies have been applied to target toxic-repeat mRNA transcripts to restore MBNL protein function in DM1 models, such as cells and mice, and in humans. This technique has had promising results in DM1 therapeutics by alleviating pathogenic phenotypes.
Collapse
|
31
|
Chong-Nguyen C, Wahbi K, Algalarrondo V, Bécane HM, Radvanyi-Hoffman H, Arnaud P, Furling D, Lazarus A, Bassez G, Béhin A, Fayssoil A, Laforêt P, Stojkovic T, Eymard B, Duboc D. Association Between Mutation Size and Cardiac Involvement in Myotonic Dystrophy Type 1: An Analysis of the DM1-Heart Registry. ACTA ACUST UNITED AC 2018; 10:CIRCGENETICS.116.001526. [PMID: 28611030 DOI: 10.1161/circgenetics.116.001526] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 03/03/2017] [Indexed: 11/16/2022]
Abstract
BACKGROUND In myotonic dystrophy type 1, the association between mutation size (CTG expansion) and the severity of cardiac involvement is controversial. METHODS AND RESULTS We selected 855 patients with myotonic dystrophy type 1 (women, 51%; median age, 37 years), with genetic testing performed at the moment of their initial cardiac evaluation, out of 1014 patients included in the Myotonic Dystrophy Type 1-Heart Registry between January 2000 and December 2015. We studied the association between CTG expansion size and other baseline characteristics and (1) cardiac involvement at baseline and (2) the incidence of death, sudden death, and other cardiac adverse events. At initial presentation, the median CTG expansion size was 530 (interquartile range, 300-830). In multivariate analysis, larger expansions were associated with the presence at baseline of conduction defects on the ECG and left ventricular systolic dysfunction. In a median 11.5 years of follow-up period, 210 patients died (25%), including 32 suddenly (4%). Supraventricular arrhythmias developed over lifetime in 166 patients (19%), sustained ventricular tachyarrhythmias in 17 (2%), and permanent pacemakers were implanted in 181 (21%). In Cox regression analyses, larger CTG expansions were significantly associated with (1) total death, sudden death, and pacemaker implantation in a model, including CTG expansion size, age, sex, diabetes mellitus, and (2) all end points except sudden death in a model including all baseline characteristics. CONCLUSIONS The size of the CTG expansion in the blood of myotonic dystrophy type 1 patients is associated with total and sudden deaths, conduction defects, left ventricular dysfunction, and supraventricular arrhythmias. CLINICAL TRIAL REGISTRATION URL: https://www.clinicaltrials.gov. Unique Identifier: NCT01136330.
Collapse
|
32
|
Abstract
More than 40 diseases, most of which primarily affect the nervous system, are caused by expansions of simple sequence repeats dispersed throughout the human genome. Expanded trinucleotide repeat diseases were discovered first and remain the most frequent. More recently tetra-, penta-, hexa-, and even dodeca-nucleotide repeat expansions have been identified as the cause of human disease, including some of the most common genetic disorders seen by neurologists. Repeat expansion diseases include both causes of myotonic dystrophy (DM1 and DM2), the most common genetic cause of amyotrophic lateral sclerosis/frontotemporal dementia (C9ORF72), Huntington disease, and eight other polyglutamine disorders, including the most common forms of dominantly inherited ataxia, the most common recessive ataxia (Friedreich ataxia), and the most common heritable mental retardation (fragile X syndrome). Here I review distinctive features of this group of diseases that stem from the unusual, dynamic nature of the underlying mutations. These features include marked clinical heterogeneity and the phenomenon of clinical anticipation. I then discuss the diverse molecular mechanisms driving disease pathogenesis, which vary depending on the repeat sequence, size, and location within the disease gene, and whether the repeat is translated into protein. I conclude with a brief clinical and genetic description of individual repeat expansion diseases that are most relevant to neurologists.
Collapse
Affiliation(s)
- Henry Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States.
| |
Collapse
|
33
|
Intrinsic Disorder in Proteins with Pathogenic Repeat Expansions. Molecules 2017; 22:molecules22122027. [PMID: 29186753 PMCID: PMC6149999 DOI: 10.3390/molecules22122027] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 11/18/2017] [Accepted: 11/21/2017] [Indexed: 11/18/2022] Open
Abstract
Intrinsically disordered proteins and proteins with intrinsically disordered regions have been shown to be highly prevalent in disease. Furthermore, disease-causing expansions of the regions containing tandem amino acid repeats often push repetitive proteins towards formation of irreversible aggregates. In fact, in disease-relevant proteins, the increased repeat length often positively correlates with the increased aggregation efficiency and the increased disease severity and penetrance, being negatively correlated with the age of disease onset. The major categories of repeat extensions involved in disease include poly-glutamine and poly-alanine homorepeats, which are often times located in the intrinsically disordered regions, as well as repeats in non-coding regions of genes typically encoding proteins with ordered structures. Repeats in such non-coding regions of genes can be expressed at the mRNA level. Although they can affect the expression levels of encoded proteins, they are not translated as parts of an affected protein and have no effect on its structure. However, in some cases, the repetitive mRNAs can be translated in a non-canonical manner, generating highly repetitive peptides of different length and amino acid composition. The repeat extension-caused aggregation of a repetitive protein may represent a pivotal step for its transformation into a proteotoxic entity that can lead to pathology. The goals of this article are to systematically analyze molecular mechanisms of the proteinopathies caused by the poly-glutamine and poly-alanine homorepeat expansion, as well as by the polypeptides generated as a result of the microsatellite expansions in non-coding gene regions and to examine the related proteins. We also present results of the analysis of the prevalence and functional roles of intrinsic disorder in proteins associated with pathological repeat expansions.
Collapse
|
34
|
Mitochondrial dysfunction in myotonic dystrophy type 1. Neuromuscul Disord 2017; 28:144-149. [PMID: 29289451 DOI: 10.1016/j.nmd.2017.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 10/23/2017] [Accepted: 10/30/2017] [Indexed: 11/20/2022]
Abstract
The pathophysiological mechanism linking the nucleotide expansion in the DMPK gene to the clinical manifestations of myotonic dystrophy type 1 (DM1) is still unclear. In vitro studies demonstrate DMPK involvement in the redox homeostasis of cells and the mitochondrial dysfunction in DM1, but in vivo investigations of oxidative metabolism in skeletal muscle have provided ambiguous results and have never been performed in the brain. Twenty-five DM1 patients (14M, 39 ± 11years) underwent brain proton MR spectroscopy (1H-MRS), and sixteen cases (9M, 40 ± 13 years old) also calf muscle phosphorus MRS (31P-MRS). Findings were compared to those of sex- and age-matched controls. Eight DM1 patients showed pathological increase of brain lactate and, compared to those without, had larger lateral ventricles (p < 0.01), smaller gray matter volumes (p < 0.05) and higher white matter lesion load (p < 0.05). A reduction of phosphocreatine/inorganic phosphate (p < 0.001) at rest and, at first minute of exercise, a lower [phosphocreatine] (p = 0.003) and greater [ADP] (p = 0.004) were found in DM1 patients compared to controls. The post-exercise indices of muscle oxidative metabolism were all impaired in DM1, including the increase of time constant of phosphocreatine resynthesis (TC PCr, p = 0.038) and the reduction of the maximum rate of mitochondrial ATP synthesis (p = 0.033). TC PCr values correlated with the myotonic area score (ρ = 0.74, p = 0.01) indicating higher impairment of muscle oxidative metabolism in clinically more affected patients. Our findings provide clear in vivo evidence of multisystem impairment of oxidative metabolism in DM1 patients, providing a rationale for targeted treatment enhancing energy metabolism.
Collapse
|
35
|
Thomas JD, Sznajder ŁJ, Bardhi O, Aslam FN, Anastasiadis ZP, Scotti MM, Nishino I, Nakamori M, Wang ET, Swanson MS. Disrupted prenatal RNA processing and myogenesis in congenital myotonic dystrophy. Genes Dev 2017; 31:1122-1133. [PMID: 28698297 PMCID: PMC5538435 DOI: 10.1101/gad.300590.117] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 05/26/2017] [Indexed: 02/06/2023]
Abstract
Thomas et al. demonstrate that RNA misprocessing is a major pathogenic factor in congenital myotonic dystrophy and provide novel mouse models to further examine roles for cotranscriptional/post-transcriptional gene regulation during tissue development. Myotonic dystrophy type 1 (DM1) is a CTG microsatellite expansion (CTGexp) disorder caused by expression of CUGexp RNAs. These mutant RNAs alter the activities of RNA processing factors, including MBNL proteins, leading to re-expression of fetal isoforms in adult tissues and DM1 pathology. While this pathogenesis model accounts for adult-onset disease, the molecular basis of congenital DM (CDM) is unknown. Here, we test the hypothesis that disruption of developmentally regulated RNA alternative processing pathways contributes to CDM disease. We identify prominent alternative splicing and polyadenylation abnormalities in infant CDM muscle, and, although most are also misregulated in adult-onset DM1, dysregulation is significantly more severe in CDM. Furthermore, analysis of alternative splicing during human myogenesis reveals that CDM-relevant exons undergo prenatal RNA isoform transitions and are predicted to be disrupted by CUGexp-associated mechanisms in utero. To test this possibility and the contribution of MBNLs to CDM pathogenesis, we generated mouse Mbnl double (Mbnl1; Mbnl2) and triple (Mbnl1; Mbnl2; Mbnl3) muscle-specific knockout models that recapitulate the congenital myopathy, gene expression, and spliceopathy defects characteristic of CDM. This study demonstrates that RNA misprocessing is a major pathogenic factor in CDM and provides novel mouse models to further examine roles for cotranscriptional/post-transcriptional gene regulation during development.
Collapse
Affiliation(s)
- James D Thomas
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Łukasz J Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Olgert Bardhi
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Faaiq N Aslam
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Zacharias P Anastasiadis
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Marina M Scotti
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Center of Neurology and Psychiatry, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Eric T Wang
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| |
Collapse
|
36
|
Barbé L, Lanni S, López-Castel A, Franck S, Spits C, Keymolen K, Seneca S, Tomé S, Miron I, Letourneau J, Liang M, Choufani S, Weksberg R, Wilson MD, Sedlacek Z, Gagnon C, Musova Z, Chitayat D, Shannon P, Mathieu J, Sermon K, Pearson CE. CpG Methylation, a Parent-of-Origin Effect for Maternal-Biased Transmission of Congenital Myotonic Dystrophy. Am J Hum Genet 2017; 100:488-505. [PMID: 28257691 PMCID: PMC5339342 DOI: 10.1016/j.ajhg.2017.01.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/26/2017] [Indexed: 12/13/2022] Open
Abstract
CTG repeat expansions in DMPK cause myotonic dystrophy (DM1) with a continuum of severity and ages of onset. Congenital DM1 (CDM1), the most severe form, presents distinct clinical features, large expansions, and almost exclusive maternal transmission. The correlation between CDM1 and expansion size is not absolute, suggesting contributions of other factors. We determined CpG methylation flanking the CTG repeat in 79 blood samples from 20 CDM1-affected individuals; 21, 27, and 11 individuals with DM1 but not CDM1 (henceforth non-CDM1) with maternal, paternal, and unknown inheritance; and collections of maternally and paternally derived chorionic villus samples (7 CVSs) and human embryonic stem cells (4 hESCs). All but two CDM1-affected individuals showed high levels of methylation upstream and downstream of the repeat, greater than non-CDM1 individuals (p = 7.04958 × 10−12). Most non-CDM1 individuals were devoid of methylation, where one in six showed downstream methylation. Only two non-CDM1 individuals showed upstream methylation, and these were maternally derived childhood onset, suggesting a continuum of methylation with age of onset. Only maternally derived hESCs and CVSs showed upstream methylation. In contrast, paternally derived samples (27 blood samples, 3 CVSs, and 2 hESCs) never showed upstream methylation. CTG tract length did not strictly correlate with CDM1 or methylation. Thus, methylation patterns flanking the CTG repeat are stronger indicators of CDM1 than repeat size. Spermatogonia with upstream methylation may not survive due to methylation-induced reduced expression of the adjacent SIX5, thereby protecting DM1-affected fathers from having CDM1-affected children. Thus, DMPK methylation may account for the maternal bias for CDM1 transmission, larger maternal CTG expansions, age of onset, and clinical continuum, and may serve as a diagnostic indicator.
Collapse
|
37
|
Smith CA, Gutmann L. Myotonic Dystrophy Type 1 Management and Therapeutics. Curr Treat Options Neurol 2016; 18:52. [DOI: 10.1007/s11940-016-0434-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
38
|
Dose-Dependent Regulation of Alternative Splicing by MBNL Proteins Reveals Biomarkers for Myotonic Dystrophy. PLoS Genet 2016; 12:e1006316. [PMID: 27681373 PMCID: PMC5082313 DOI: 10.1371/journal.pgen.1006316] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 08/23/2016] [Indexed: 01/23/2023] Open
Abstract
Alternative splicing is a regulated process that results in expression of
specific mRNA and protein isoforms. Alternative splicing factors determine the
relative abundance of each isoform. Here we focus on MBNL1, a splicing factor
misregulated in the disease myotonic dystrophy. By altering the concentration of
MBNL1 in cells across a broad dynamic range, we show that different splicing
events require different amounts of MBNL1 for half-maximal response, and respond
more or less steeply to MBNL1. Motifs around MBNL1 exon 5 were studied to assess
how cis-elements mediate the MBNL1 dose-dependent splicing
response. A framework was developed to estimate MBNL concentration using
splicing responses alone, validated in the cell-based model, and applied to
myotonic dystrophy patient muscle. Using this framework, we evaluated the
ability of individual and combinations of splicing events to predict functional
MBNL concentration in human biopsies, as well as their performance as biomarkers
to assay mild, moderate, and severe cases of DM. Our studies provide insight into the mechanisms of myotonic dystrophy, the most
common adult form of muscular dystrophy. In this disease, a family of RNA
binding proteins is sequestered by toxic RNA, which leads to mis-regulation and
disease symptoms. We have created a cellular model with one of these family
members to study how these RNA binding proteins function in the absence of the
toxic RNA. In parallel, we analyzed transcriptomic data from over 50 individuals
(44 affected by myotonic dystrophy) with a range of disease severity. The
results from the transcriptomic data provide a rational approach to select
biomarkers for clinical research and therapeutic trials.
Collapse
|
39
|
Nistal M, Paniagua R, González-Peramato P, Reyes-Múgica M. Perspectives in Pediatric Pathology, Chapter 17. Other Hypergonadotropic Hypogonadisms. Pediatr Dev Pathol 2016; 19:278-90. [PMID: 26809023 DOI: 10.2350/16-01-1755-pb.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Manuel Nistal
- 1 Department of Pathology, Hospital La Paz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Ricardo Paniagua
- 2 Department of Cell Biology, Universidad de Alcala, Madrid, Spain
| | | | - Miguel Reyes-Múgica
- 3 Department of Pathology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| |
Collapse
|
40
|
Acket B, Lepage B, Maury P, Arne-Bes MC, Cintas P. Chloride channel dysfunction study in myotonic dystrophy type 1 using repeated short exercise tests. Muscle Nerve 2016; 54:104-9. [DOI: 10.1002/mus.25003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2015] [Indexed: 11/05/2022]
Affiliation(s)
- Blandine Acket
- Service de Neurologie; Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan; 1 Place Baylac 31059 Toulouse France
| | - Benoit Lepage
- Clinical Epidemiology Unit; Centre Hospitalier Universitaire de Toulouse; Faculté de Médecine de Purpan Toulouse France
| | - Philippe Maury
- Federation of Cardiology; Centre Hospitalier Universitaire de Toulouse, Hôpital Rangueil; Toulouse France
| | - Marie-Christine Arne-Bes
- Service de Neurologie; Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan; 1 Place Baylac 31059 Toulouse France
| | - Pascal Cintas
- Service de Neurologie; Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan; 1 Place Baylac 31059 Toulouse France
| |
Collapse
|
41
|
Ravel-Chapuis A, Klein Gunnewiek A, Bélanger G, Crawford Parks TE, Côté J, Jasmin BJ. Staufen1 impairs stress granule formation in skeletal muscle cells from myotonic dystrophy type 1 patients. Mol Biol Cell 2016; 27:1728-39. [PMID: 27030674 PMCID: PMC4884064 DOI: 10.1091/mbc.e15-06-0356] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 03/25/2016] [Indexed: 11/11/2022] Open
Abstract
Myotonic dystrophy (DM1) is caused by an expansion of CUG repeats (CUG(exp)) in the DMPK mRNA 3'UTR. CUG(exp)-containing mRNAs become toxic to cells by misregulating RNA-binding proteins. Here we investigated the consequence of this RNA toxicity on the cellular stress response. We report that cell stress efficiently triggers formation of stress granules (SGs) in proliferating, quiescent, and differentiated muscle cells, as shown by the appearance of distinct cytoplasmic TIA-1- and DDX3-containing foci. We show that Staufen1 is also dynamically recruited into these granules. Moreover, we discovered that DM1 myoblasts fail to properly form SGs in response to arsenite. This blockage was not observed in DM1 fibroblasts, demonstrating a cell type-specific defect. DM1 myoblasts display increased expression and sequestration of toxic CUG(exp) mRNAs compared with fibroblasts. Of importance, down-regulation of Staufen1 in DM1 myoblasts rescues SG formation. Together our data show that Staufen1 participates in the inhibition of SG formation in DM1 myoblasts. These results reveal that DM1 muscle cells fail to properly respond to stress, thereby likely contributing to the complex pathogenesis of DM1.
Collapse
Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Amanda Klein Gunnewiek
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Guy Bélanger
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Tara E Crawford Parks
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| |
Collapse
|
42
|
Guindalini RSC, Song A, Fackenthal JD, Olopade OI, Huo D. Genetic anticipation in BRCA1/BRCA2 families after controlling for ascertainment bias and cohort effect. Cancer 2016; 122:1913-20. [PMID: 26992017 DOI: 10.1002/cncr.29972] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/12/2016] [Accepted: 02/08/2016] [Indexed: 11/09/2022]
Abstract
BACKGROUND Genetic anticipation, the earlier onset of disease in successive generations, has been reported in hereditary breast and ovarian cancer syndrome (HBOC), but little is known about its underlying mechanisms. Ascertainment bias has been suggested as a reason in previous studies. Likewise, cohort effect, which may be caused by environmental factors, can be misinterpreted as genetic anticipation. METHODS The authors reviewed the pedigrees of 176 kindreds, segregating those with deleterious mutations in breast cancer genes 1 and 2 (BRCA1/BRCA2) who had at least 2 consecutive generations of the same cancer (breast or ovarian). By using mutation probabilities as analytical weights in weighted random-effect models, generational differences in the age at onset of breast/ovarian cancer were calculated. The analyses were further controlled for ascertainment bias by excluding probands and adjusting for birth-cohort effect in the anticipation models. RESULTS The mean age at the onset of breast cancer for the probands' generation was 41.9 years, which was 6.8 years and 9.8 years earlier than the parents' and grandparents' generations, respectively. The anticipation effect for breast cancer remained significant after excluding the probands. There was a birth-cohort effect: patients who were born in 1930s and 1940s had breast cancer 5.0 years and 7.6 years earlier than patients who were born before 1920. The difference in breast cancer age of onset across generations was no longer significant after adjusting for birth-cohort effect. CONCLUSIONS The observed anticipation effect was driven mainly by a decrease in age of onset across birth cohorts, underscoring the need for risk-reducing interventions that target changing environmental/lifestyle factors in BRCA1/BRCA2 carriers. Cancer 2016;122:1913-20. © 2016 American Cancer Society.
Collapse
Affiliation(s)
- Rodrigo Santa Cruz Guindalini
- Department of Medicine, Center for Clinical Cancer Genetics and Global Health, The University of Chicago, Chicago, Illinois.,Department of Radiology and Oncology, The State of Sao Paulo Cancer Institute, University of Sao Paulo Medical School, Sao Paulo, Brazil.,Clínica de Oncologia (CLION), Clínica de Assistência à Mulher (CAM) Group, Salvador, Bahia, Brazil
| | - Andrew Song
- Department of Medicine, Center for Clinical Cancer Genetics and Global Health, The University of Chicago, Chicago, Illinois
| | - James D Fackenthal
- Department of Medicine, Center for Clinical Cancer Genetics and Global Health, The University of Chicago, Chicago, Illinois
| | - Olufunmilayo I Olopade
- Department of Medicine, Center for Clinical Cancer Genetics and Global Health, The University of Chicago, Chicago, Illinois
| | - Dezheng Huo
- Department of Medicine, Center for Clinical Cancer Genetics and Global Health, The University of Chicago, Chicago, Illinois.,Department of Public Health Sciences, The University of Chicago, Chicago, Illinois
| |
Collapse
|
43
|
Rzuczek SG, Southern MR, Disney MD. Studying a Drug-like, RNA-Focused Small Molecule Library Identifies Compounds That Inhibit RNA Toxicity in Myotonic Dystrophy. ACS Chem Biol 2015; 10:2706-15. [PMID: 26414664 DOI: 10.1021/acschembio.5b00430] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There are many RNA targets in the transcriptome to which small molecule chemical probes and lead therapeutics are desired. However, identifying compounds that bind and modulate RNA function in cellulo is difficult. Although rational design approaches have been developed, they are still in their infancies and leave many RNAs "undruggable". In an effort to develop a small molecule library that is biased for binding RNA, we computationally identified "drug-like" compounds from screening collections that have favorable properties for binding RNA and for suitability as lead drugs. As proof-of-concept, this collection was screened for binding to and modulating the cellular dysfunction of the expanded repeating RNA (r(CUG)(exp)) that causes myotonic dystrophy type 1. Hit compounds bind the target in cellulo, as determined by the target identification approach Competitive Chemical Cross-Linking and Isolation by Pull-down (C-ChemCLIP), and selectively improve several disease-associated defects. The best compounds identified from our 320-member library are more potent in cellulo than compounds identified by high-throughput screening (HTS) campaigns against this RNA. Furthermore, the compound collection has a higher hit rate (9% compared to 0.01-3%), and the bioactive compounds identified are not charged; thus, RNA can be "drugged" with compounds that have favorable pharmacological properties. Finally, this RNA-focused small molecule library may serve as a useful starting point to identify lead "drug-like" chemical probes that affect the biological (dys)function of other RNA targets by direct target engagement.
Collapse
Affiliation(s)
- Suzanne G. Rzuczek
- Department
of Chemistry and ‡Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #3A1, Jupiter, Florida 33458, United States
| | - Mark R. Southern
- Department
of Chemistry and ‡Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #3A1, Jupiter, Florida 33458, United States
| | - Matthew D. Disney
- Department
of Chemistry and ‡Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #3A1, Jupiter, Florida 33458, United States
| |
Collapse
|
44
|
Abstract
For many decades, the major function of mRNA was thought to be to provide protein-coding information embedded in the genome. The advent of high-throughput sequencing has led to the discovery of pervasive transcription of eukaryotic genomes and opened the world of RNA-mediated gene regulation. Many regulatory RNAs have been found to be incapable of protein coding and are hence termed as non-coding RNAs (ncRNAs). However, studies in recent years have shown that several previously annotated non-coding RNAs have the potential to encode proteins, and conversely, some coding RNAs have regulatory functions independent of the protein they encode. Such bi-functional RNAs, with both protein coding and non-coding functions, which we term as 'cncRNAs', have emerged as new players in cellular systems. Here, we describe the functions of some cncRNAs identified from bacteria to humans. Because the functions of many RNAs across genomes remains unclear, we propose that RNAs be classified as coding, non-coding or both only after careful analysis of their functions.
Collapse
Affiliation(s)
- Pooja Kumari
- Division of Biomedical Cell Biology, Warwick Medical School, The University of Warwick, Gibbet Hill Road, Coventry CV47AJ, United Kingdom
| | - Karuna Sampath
- Division of Biomedical Cell Biology, Warwick Medical School, The University of Warwick, Gibbet Hill Road, Coventry CV47AJ, United Kingdom.
| |
Collapse
|
45
|
Ho G, Cardamone M, Farrar M. Congenital and childhood myotonic dystrophy: Current aspects of disease and future directions. World J Clin Pediatr 2015; 4:66-80. [PMID: 26566479 PMCID: PMC4637811 DOI: 10.5409/wjcp.v4.i4.66] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/07/2015] [Accepted: 09/25/2015] [Indexed: 02/06/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is multisystem disease arising from mutant CTG expansion in the non-translating region of the dystrophia myotonica protein kinase gene. While DM1 is the most common adult muscular dystrophy, with a worldwide prevalence of one in eight thousand, age of onset varies from before birth to adulthood. There is a broad spectrum of clinical severity, ranging from mild to severe, which correlates with number of DNA repeats. Importantly, the early clinical manifestations and management in congenital and childhood DM1 differ from classic adult DM1. In neonates and children, DM1 predominantly affects muscle strength, cognition, respiratory, central nervous and gastrointestinal systems. Sleep disorders are often under recognised yet a significant morbidity. No effective disease modifying treatment is currently available and neonates and children with DM1 may experience severe physical and intellectual disability, which may be life limiting in the most severe forms. Management is currently supportive, incorporating regular surveillance and treatment of manifestations. Novel therapies, which target the gene and the pathogenic mechanism of abnormal splicing are emerging. Genetic counselling is critical in this autosomal dominant genetic disease with variable penetrance and potential maternal anticipation, as is assisting with family planning and undertaking cascade testing to instigate health surveillance in affected family members. This review incorporates discussion of the clinical manifestations and management of congenital and childhood DM1, with a particular focus on hypersomnolence and sleep disorders. In addition, the molecular genetics, mechanisms of disease pathogenesis and development of novel treatment strategies in DM1 will be summarised.
Collapse
|
46
|
Van Den Hende K, Durand S, Mesnage R, Filleron A, Cambonie G. [Congenital myotonic dystrophy type I in a very premature neonate: ethical concerns]. Arch Pediatr 2015; 22:1042-6. [PMID: 26321353 DOI: 10.1016/j.arcped.2015.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 06/22/2015] [Accepted: 07/06/2015] [Indexed: 10/23/2022]
Abstract
UNLABELLED The congenital form of myotonic dystrophy type I (CDM1) corresponds to a>1500 expansion of an unstable trinucleotide (CTG) repeat. Two prognostic factors predict the risk of death in early infancy: maturity of less than 35 weeks of gestation and neonatal invasive ventilation for more than 30 days. OBSERVATION The case of a 29-week-old premature female infant, conceived by in vitro fertilization, is reported. Generalized hypotonia led to the diagnosis of the disease. Ethical concertation about withdrawal or maintenance of intensive care was engaged, taking into account the prolonged ventilation, the degree of prematurity, and the parental wishes for maximum care. The infant was extubated after 2 months. At 17 months, motor development and precursors of language were delayed, and difficulties in feeding had required a gastrostomy. DISCUSSION Technical advances in neonatal intensive care now allow CDM1 children to survive prolonged ventilation. The signification of such ventilatory needs on patient outcome, particularly for motor handicaps, speech and language delay, and mental deficiency, remains uncertain. The potential impact of in vitro fertilization on disease expression may also be considered. CONCLUSION CDM1 is a severe condition, but variability in clinical manifestations and absence of genotype-phenotype correlation result in problems predicting prognosis at the individual level. Ethical issues about the level of care, notably for tracheostomy and gastrostomy, should be adapted to each case, in partnership with parents.
Collapse
Affiliation(s)
- K Van Den Hende
- Département de pédiatrie néonatale et réanimations, pôle hospitalo-universitaire Femme-Mère-Enfant, hôpital Arnaud-de-Villeneuve, centre hospitalier régional universitaire de Montpellier, 371, avenue du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France
| | - S Durand
- Département de pédiatrie néonatale et réanimations, pôle hospitalo-universitaire Femme-Mère-Enfant, hôpital Arnaud-de-Villeneuve, centre hospitalier régional universitaire de Montpellier, 371, avenue du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France.
| | - R Mesnage
- Département de pédiatrie néonatale et réanimations, pôle hospitalo-universitaire Femme-Mère-Enfant, hôpital Arnaud-de-Villeneuve, centre hospitalier régional universitaire de Montpellier, 371, avenue du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France
| | - A Filleron
- Service de pédiatrie, hôpital Carémeau, centre hospitalier régional universitaire de Nîmes, place du Professeur-Debré, 30029 Nîmes cedex 9, France
| | - G Cambonie
- Département de pédiatrie néonatale et réanimations, pôle hospitalo-universitaire Femme-Mère-Enfant, hôpital Arnaud-de-Villeneuve, centre hospitalier régional universitaire de Montpellier, 371, avenue du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France
| |
Collapse
|
47
|
Morihara R, Hishikawa N, Yamashita T, Deguchi K, Kurata T, Abe K. Selective disappearance of medial back muscles in a case of myotonic dystrophy type 1. J Neurol Sci 2015; 353:185-6. [PMID: 25940325 DOI: 10.1016/j.jns.2015.04.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 04/07/2015] [Accepted: 04/14/2015] [Indexed: 11/16/2022]
Abstract
Here, we report a unique case of late-onset myotonic dystrophy type 1 in a 64-year-old woman, with selective disappearance of the medial lower back muscles. We compared the clinical features of this patient with those of a cohort of 29 patients with myotonic dystrophy type 1 to clarify the correlation between clinical features and lower back muscle atrophy. After classification into three subgroups according to muscle atrophy pattern, medial muscle atrophy was present in 17.2% of the patients. Affected patients were older at onset than non-affected patients, and limb muscle power and respiratory function decreased with atrophy progression.
Collapse
Affiliation(s)
- Ryuta Morihara
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
| | - Nozomi Hishikawa
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
| | - Toru Yamashita
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
| | - Kentaro Deguchi
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
| | - Tomoko Kurata
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
| | - Koji Abe
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, 2-5-1 Shikata-cho, Okayama 700-8558, Japan.
| |
Collapse
|
48
|
Abstract
DNA repair normally protects the genome against mutations that threaten genome integrity and thus cell viability. However, growing evidence suggests that in the case of the Repeat Expansion Diseases, disorders that result from an increase in the size of a disease-specific microsatellite, the disease-causing mutation is actually the result of aberrant DNA repair. A variety of proteins from different DNA repair pathways have thus far been implicated in this process. This review will summarize recent findings from patients and from mouse models of these diseases that shed light on how these pathways may interact to cause repeat expansion.
Collapse
Affiliation(s)
- Xiao-Nan Zhao
- Section on Genomic Structure and Function Laboratory of Cell and Molecular Biology National Institute of Diabetes, Digestive and Kidney Diseases National Institutes of Health, Bethesda, MD 20892-0830, USA
| | - Karen Usdin
- Section on Genomic Structure and Function Laboratory of Cell and Molecular Biology National Institute of Diabetes, Digestive and Kidney Diseases National Institutes of Health, Bethesda, MD 20892-0830, USA.
| |
Collapse
|
49
|
Pratte A, Prévost C, Puymirat J, Mathieu J. Anticipation in myotonic dystrophy type 1 parents with small CTG expansions. Am J Med Genet A 2015; 167A:708-14. [DOI: 10.1002/ajmg.a.36950] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 12/21/2014] [Indexed: 11/05/2022]
Affiliation(s)
- Annabelle Pratte
- Division of Genetic Counseling; CSSS Chicoutimi, Chicoutimi; Quebec Canada
| | - Claude Prévost
- Neuromuscular Clinic; CSSS Jonquiere; Jonquiere Quebec Canada
| | - Jack Puymirat
- Department of Human Genetics; Centre Hospitalier de l'Université Laval; Quebec Quebec Canada
| | - Jean Mathieu
- Faculty of Medicine and Health Sciences; Sherbrooke University; Sherbrooke Quebec Canada
- Neuromuscular Clinic; CSSS Jonquiere; Jonquiere Quebec Canada
| |
Collapse
|
50
|
Kern A, Seitz O. Template-directed ligation on repetitive DNA sequences: a chemical method to probe the length of Huntington DNA. Chem Sci 2015; 6:724-728. [PMID: 28706635 PMCID: PMC5494559 DOI: 10.1039/c4sc01974a] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/16/2014] [Indexed: 01/17/2023] Open
Abstract
Several genomic disorders are caused by an excessive number of DNA triplet repeats. We developed a DNA-templated reaction in which product formation occurs only when the number of repeats exceeds a threshold indicative for the outbreak of Chorea Huntington. The combined use of native chemical PNA ligation and auxiliary DNA probes enabled reactions on templates obtained from human genomic DNA.
Collapse
Affiliation(s)
- Anika Kern
- Institut für Chemie , Humboldt-Universität zu Berlin , Brook-Taylor-Straße 2 , 12489 Berlin , Germany .
| | - Oliver Seitz
- Institut für Chemie , Humboldt-Universität zu Berlin , Brook-Taylor-Straße 2 , 12489 Berlin , Germany .
| |
Collapse
|