201
|
Zhang Y, Long C, Bassel-Duby R, Olson EN. Myoediting: Toward Prevention of Muscular Dystrophy by Therapeutic Genome Editing. Physiol Rev 2018; 98:1205-1240. [PMID: 29717930 DOI: 10.1152/physrev.00046.2017] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Muscular dystrophies represent a large group of genetic disorders that significantly impair quality of life and often progress to premature death. There is no effective treatment for these debilitating diseases. Most therapies, developed to date, focus on alleviating the symptoms or targeting the secondary effects, while the underlying gene mutation is still present in the human genome. The discovery and application of programmable nucleases for site-specific DNA double-stranded breaks provides a powerful tool for precise genome engineering. In particular, the CRISPR/Cas system has revolutionized the genome editing field and is providing a new path for disease treatment by targeting the disease-causing genetic mutations. In this review, we provide a historical overview of genome-editing technologies, summarize the most recent advances, and discuss potential strategies and challenges for permanently correcting genetic mutations that cause muscular dystrophies.
Collapse
Affiliation(s)
- Yu Zhang
- Department of Molecular Biology, Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Chengzu Long
- Department of Molecular Biology, Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Rhonda Bassel-Duby
- Department of Molecular Biology, Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Eric N Olson
- Department of Molecular Biology, Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| |
Collapse
|
202
|
Multiple Exon Skipping in the Duchenne Muscular Dystrophy Hot Spots: Prospects and Challenges. J Pers Med 2018; 8:jpm8040041. [PMID: 30544634 PMCID: PMC6313462 DOI: 10.3390/jpm8040041] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/24/2018] [Accepted: 12/04/2018] [Indexed: 12/19/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), a fatal X-linked recessive disorder, is caused mostly by frame-disrupting, out-of-frame deletions in the dystrophin (DMD) gene. Antisense oligonucleotide-mediated exon skipping is a promising therapy for DMD. Exon skipping aims to convert out-of-frame mRNA to in-frame mRNA and induce the production of internally-deleted dystrophin as seen in the less severe Becker muscular dystrophy. Currently, multiple exon skipping has gained special interest as a new therapeutic modality for this approach. Previous retrospective database studies represented a potential therapeutic application of multiple exon skipping. Since then, public DMD databases have become more useful with an increase in patient registration and advances in molecular diagnosis. Here, we provide an update on DMD genotype-phenotype associations using a global DMD database and further provide the rationale for multiple exon skipping development, particularly for exons 45–55 skipping and an emerging therapeutic concept, exons 3–9 skipping. Importantly, this review highlights the potential of multiple exon skipping for enabling the production of functionally-corrected dystrophin and for treating symptomatic patients not only with out-of-frame deletions but also those with in-frame deletions. We will also discuss prospects and challenges in multiple exon skipping therapy, referring to recent progress in antisense chemistry and design, as well as disease models.
Collapse
|
203
|
Zampatti S, Mela J, Peconi C, Pagliaroli G, Carboni S, Barrano G, Zito I, Cascella R, Marella G, Milano F, Arcangeli M, Caltagirone C, Novelli A, Giardina E. Identification of Duchenne/Becker muscular dystrophy mosaic carriers through a combined DNA/RNA analysis. Prenat Diagn 2018; 38:1096-1102. [PMID: 30303263 DOI: 10.1002/pd.5369] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 08/22/2018] [Accepted: 10/02/2018] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The Duchenne/Becker muscular dystrophy (DMD) carrier screening includes the evaluation of mutations in DMD gene, and the most widely used analysis is the multiplex ligation-dependent probe amplification (MLPA) for the DMD deletions/duplications detection. The high frequency of de novo mutations permits to estimate a risk up to 20% of mosaicisms for mothers of sporadic DMD children. The purpose of this study is to evaluate alternative analytical strategy for the detection of mosaics carrier women, in order to improve the recurrence risk estimation. METHOD Different DNA and RNA analyses were conducted on samples from a woman that conceived a DMD fetus without previous family history of dystrophynopathy. RESULTS Standard MLPA analysis failed to identify mosaicism, even if MLPA doses suggested it. Electrophoresis and direct sequencing conducted on RNA permitted to detect two different amplicons of cDNAs, demonstrating the presence of somatic mosaicism. Subsequent detection of a second affected fetus confirmed the mosaic status on the mother. CONCLUSION The implementation of RNA analysis in diagnostic algorithm can increase the sensitivity of carrier test for mothers of sporadic affected patients, permitting detection of mosaic status. A revision of analytical guidelines is needed in order to improve the recurrence risk estimation and support prenatal genetic counseling.
Collapse
Affiliation(s)
- Stefania Zampatti
- Molecular Genetics Laboratory UILDM, Santa Lucia Foundation, IRCCS, Rome, Italy
| | - Julia Mela
- Molecular Genetics Laboratory UILDM, Santa Lucia Foundation, IRCCS, Rome, Italy
| | - Cristina Peconi
- Molecular Genetics Laboratory UILDM, Santa Lucia Foundation, IRCCS, Rome, Italy
| | - Giulia Pagliaroli
- Molecular Genetics Laboratory UILDM, Santa Lucia Foundation, IRCCS, Rome, Italy
| | - Stefania Carboni
- Molecular Genetics Laboratory UILDM, Santa Lucia Foundation, IRCCS, Rome, Italy
| | - Giuseppe Barrano
- S. Pietro Fatebenefratelli Hospital, UOSD Medical Genetics, Rome, Italy
| | - Ilaria Zito
- S. Pietro Fatebenefratelli Hospital, UOSD Medical Genetics, Rome, Italy
| | - Raffaella Cascella
- Department of Biomedicine and Prevention, School of Medicine, University of Rome 'Tor Vergata', Rome, Italy.,Department of Chemical-Toxicological and Pharmacological Evaluation of Drugs, Catholic University Our Lady of Good Counsel, Tirana, Albania
| | - Gianluca Marella
- Department of Experimental Medicine and Surgery, School of Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Filippo Milano
- Department of Biomedicine and Prevention, School of Medicine, University of Rome 'Tor Vergata', Rome, Italy
| | - Mauro Arcangeli
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Carlo Caltagirone
- Laboratory of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation
| | - Antonio Novelli
- S. Pietro Fatebenefratelli Hospital, UOSD Medical Genetics, Rome, Italy.,Medical Genetics Unit, Medical Genetics Laboratory, Bambino Gesù Pediatric Hospital, IRCCS, Rome, Italy
| | - Emiliano Giardina
- Molecular Genetics Laboratory UILDM, Santa Lucia Foundation, IRCCS, Rome, Italy.,Department of Biomedicine and Prevention, School of Medicine, University of Rome 'Tor Vergata', Rome, Italy
| |
Collapse
|
204
|
Bailey M, Miller N. DMD Open-access Variant Explorer (DOVE): A scalable, open-access, web-based tool to aid in clinical interpretation of genetic variants in the DMD gene. Mol Genet Genomic Med 2018; 7:e00510. [PMID: 30450799 PMCID: PMC6382494 DOI: 10.1002/mgg3.510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 09/24/2018] [Accepted: 10/05/2018] [Indexed: 01/04/2023] Open
Abstract
Background Duchenne muscular dystrophy (Duchenne) is caused by pathogenic variants in the DMD gene. Antisense oligonucleotides (AONs) are one emerging precision medicine treatment for Duchenne. DMD molecular genetic testing results guide precision‐therapy molecular eligibility, requiring healthcare providers to perform analyses currently uncommon in clinical laboratory and medical practices. Clear DMD variant notation and interpretation are key components of clinical care with the availability of precision medicine. Methods The DMD Open‐access Variant Explorer (DOVE) is a web‐based aid for DMD variant interpretation which additionally reports variant‐specific predicted molecular eligibility for therapy. DOVE was developed in Python and adapted to the Django Web framework, integrates existing open‐access tools, and does not rely on previous variant report/classification. Results DOVE [www.dmd.nl/DOVE] interprets colloquial and HGMD inputs of DMD variants to output HGMD variant nomenclature, theoretical molecular eligibility for therapy, and any predicted deleterious molecular consequences of therapy. DOVE relies on holistic in silico prediction of molecular eligibility for therapy in lieu of reference to an empirically defined, “variant‐eligible” list. Examples illustrate the advantage and necessity for holistic variant interpretation. Conclusion DOVE may prove useful for variant interpretation both at patient‐level and in large‐scale programs such as newborn screening and has broad application in concept to molecular genetic test result interpretation.
Collapse
|
205
|
Abstract
The ability to efficiently modify the genome using CRISPR technology has rapidly revolutionized biology and genetics and will soon transform medicine. Duchenne muscular dystrophy (DMD) represents one of the first monogenic disorders that has been investigated with respect to CRISPR-mediated correction of causal genetic mutations. DMD results from mutations in the gene encoding dystrophin, a scaffolding protein that maintains the integrity of striated muscles. Thousands of different dystrophin mutations have been identified in DMD patients, who suffer from a loss of ambulation followed by respiratory insufficiency, heart failure, and death by the third decade of life. Using CRISPR to bypass DMD mutations, dystrophin expression has been efficiently restored in human cells and mouse models of DMD. Here, we review recent progress toward the development of possible CRISPR therapies for DMD and highlight opportunities and potential obstacles in attaining this goal.
Collapse
Affiliation(s)
- Yi-Li Min
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
| | - Rhonda Bassel-Duby
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
| | - Eric N Olson
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
| |
Collapse
|
206
|
Personalized gene and cell therapy for Duchenne Muscular Dystrophy. Neuromuscul Disord 2018; 28:803-824. [DOI: 10.1016/j.nmd.2018.06.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 06/19/2018] [Accepted: 06/22/2018] [Indexed: 01/09/2023]
|
207
|
Abstract
Duchenne muscular dystrophy (DMD) is a progressive X-linked degenerative muscle disease due to mutations in the DMD gene. Genetic confirmation has become standard in recent years. Improvements in the standard of care for DMD have led to improved survival. Novel treatments for DMD have focused on reducing the dystrophic mechanism of the muscle disease, modulating utrophin protein expression, and restoring dystrophin protein expression. Among the strategies to reduce the dystrophic mechanisms are 1) inhibiting inflammation, 2) promoting muscle growth and regeneration, 3) reducing fibrosis, and 4) facilitating mitochondrial function. The agents under investigation include a novel steroid, myostatin inhibitors, idebenone, an anti-CTGF antibody, a histone deacetylase inhibitor, and cardiosphere-derived cells. For utrophin modulation, AAV-mediated gene therapy with GALGT2 is currently being investigated to upregulate utrophin expression. Finally, the strategies for dystrophin protein restoration include 1) nonsense readthrough, 2) synthetic antisense oligonucleotides for exon skipping, and 3) AAV-mediated micro/minidystrophin gene delivery. With newer agents, we are witnessing the use of more advanced biotechnological methods. Although these potential breakthroughs provide significant promise, they may also raise new questions regarding treatment effect and safety.
Collapse
Affiliation(s)
- Perry B Shieh
- Department of Neurology, University of California, Los Angeles, 300 Medical Plaza, Suite B-200, Los Angeles, CA, 90095, USA.
| |
Collapse
|
208
|
Genetic and pharmacological regulation of the endocannabinoid CB1 receptor in Duchenne muscular dystrophy. Nat Commun 2018; 9:3950. [PMID: 30262909 PMCID: PMC6160489 DOI: 10.1038/s41467-018-06267-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 08/22/2018] [Indexed: 12/14/2022] Open
Abstract
The endocannabinoid system refers to a widespread signaling system and its alteration is implicated in a growing number of human diseases. However, the potential role of endocannabinoids in skeletal muscle disorders remains unknown. Here we report the role of the endocannabinoid CB1 receptors in Duchenne's muscular dystrophy. In murine and human models, CB1 transcripts show the highest degree of expression at disease onset, and then decline overtime. Similar changes are observed for PAX7, a key regulator of muscle stem cells. Bioinformatics and biochemical analysis reveal that PAX7 binds and upregulates the CB1 gene in dystrophic more than in healthy muscles. Rimonabant, an antagonist of CB1, promotes human satellite cell differentiation in vitro, increases the number of regenerated myofibers, and prevents locomotor impairment in dystrophic mice. In conclusion, our study uncovers a PAX7-CB1 cross talk potentially exacerbating DMD and highlights the role of CB1 receptors as target for potential therapies.
Collapse
|
209
|
Dystrophin Cardiomyopathies: Clinical Management, Molecular Pathogenesis and Evolution towards Precision Medicine. J Clin Med 2018; 7:jcm7090291. [PMID: 30235804 PMCID: PMC6162458 DOI: 10.3390/jcm7090291] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/02/2018] [Accepted: 09/14/2018] [Indexed: 12/16/2022] Open
Abstract
Duchenne’s muscular dystrophy is an X-linked neuromuscular disease that manifests as muscle atrophy and cardiomyopathy in young boys. However, a considerable percentage of carrier females are often diagnosed with cardiomyopathy at an advanced stage. Existing therapy is not disease-specific and has limited effect, thus many patients and symptomatic carrier females prematurely die due to heart failure. Early detection is one of the major challenges that muscular dystrophy patients, carrier females, family members and, research and medical teams face in the complex course of dystrophic cardiomyopathy management. Despite the widespread adoption of advanced imaging modalities such as cardiac magnetic resonance, there is much scope for refining the diagnosis and treatment of dystrophic cardiomyopathy. This comprehensive review will focus on the pertinent clinical aspects of cardiac disease in muscular dystrophy while also providing a detailed consideration of the known and developing concepts in the pathophysiology of muscular dystrophy and forthcoming therapeutic options.
Collapse
|
210
|
Sagheddu R, Chiappalupi S, Salvadori L, Riuzzi F, Donato R, Sorci G. Targeting RAGE as a potential therapeutic approach to Duchenne muscular dystrophy. Hum Mol Genet 2018; 27:3734-3746. [DOI: 10.1093/hmg/ddy288] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 07/30/2018] [Indexed: 12/21/2022] Open
Affiliation(s)
- Roberta Sagheddu
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
- Interuniversity Institute of Myology (IIM)
| | - Sara Chiappalupi
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
- Interuniversity Institute of Myology (IIM)
| | - Laura Salvadori
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
- Interuniversity Institute of Myology (IIM)
| | - Francesca Riuzzi
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
- Interuniversity Institute of Myology (IIM)
| | - Rosario Donato
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
- Interuniversity Institute of Myology (IIM)
- Centro Universitario di Ricerca sulla Genomica Funzionale, University of Perugia, Perugia, Italy
| | - Guglielmo Sorci
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
- Interuniversity Institute of Myology (IIM)
| |
Collapse
|
211
|
Khodabukus A, Prabhu N, Wang J, Bursac N. In Vitro Tissue-Engineered Skeletal Muscle Models for Studying Muscle Physiology and Disease. Adv Healthc Mater 2018; 7:e1701498. [PMID: 29696831 PMCID: PMC6105407 DOI: 10.1002/adhm.201701498] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 02/18/2018] [Indexed: 12/18/2022]
Abstract
Healthy skeletal muscle possesses the extraordinary ability to regenerate in response to small-scale injuries; however, this self-repair capacity becomes overwhelmed with aging, genetic myopathies, and large muscle loss. The failure of small animal models to accurately replicate human muscle disease, injury and to predict clinically-relevant drug responses has driven the development of high fidelity in vitro skeletal muscle models. Herein, the progress made and challenges ahead in engineering biomimetic human skeletal muscle tissues that can recapitulate muscle development, genetic diseases, regeneration, and drug response is discussed. Bioengineering approaches used to improve engineered muscle structure and function as well as the functionality of satellite cells to allow modeling muscle regeneration in vitro are also highlighted. Next, a historical overview on the generation of skeletal muscle cells and tissues from human pluripotent stem cells, and a discussion on the potential of these approaches to model and treat genetic diseases such as Duchenne muscular dystrophy, is provided. Finally, the need to integrate multiorgan microphysiological systems to generate improved drug discovery technologies with the potential to complement or supersede current preclinical animal models of muscle disease is described.
Collapse
Affiliation(s)
- Alastair Khodabukus
- Department of Biomedical Engineering Duke University 101 Science Drive, FCIEMAS 1427, Durham, NC 27708-90281, USA
| | - Neel Prabhu
- Department of Biomedical Engineering Duke University 101 Science Drive, FCIEMAS 1427, Durham, NC 27708-90281, USA
| | - Jason Wang
- Department of Biomedical Engineering Duke University 101 Science Drive, FCIEMAS 1427, Durham, NC 27708-90281, USA
| | - Nenad Bursac
- Department of Biomedical Engineering Duke University 101 Science Drive, FCIEMAS 1427, Durham, NC 27708-90281, USA
| |
Collapse
|
212
|
Xu M, Xiong H, Han Y, Li C, Mai S, Huang Z, Ai X, Guo Z, Zeng F, Guo Q. Identification of Mutation Regions on NF1 Responsible for High- and Low-Risk Development of Optic Pathway Glioma in Neurofibromatosis Type I. Front Genet 2018; 9:270. [PMID: 30087692 PMCID: PMC6066643 DOI: 10.3389/fgene.2018.00270] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 07/03/2018] [Indexed: 12/30/2022] Open
Abstract
Neurofibromatosis type I is a rare neurocutaneous syndrome resulting from loss-of-function mutations of NF1. The present study sought to determine a correlation between mutation regions on NF1 and the risk of developing optic pathway glioma (OPG) in patients with neurofibromatosis type I. A total of 215 patients with neurofibromatosis type I, from our clinic or previously reported literature, were included in the study after applying strict inclusion and exclusion criteria. Of these, 100 patients with OPG were classified into the OPG group and 115 patients without OPG (aged ≥ 10 years) were assigned to the Non-OPG group. Correlation between different mutation regions and risk of OPG was analyzed. The mutation clustering in the 5′ tertile of NF1 was not significantly different between OPG and Non-OPG groups (P = 0.131). Interestingly, patients with mutations in the cysteine/serine-rich domain of NF1 had a higher risk of developing OPG than patients with mutations in other regions [P = 0.019, adjusted odds ratio (OR) = 2.587, 95% confidence interval (CI) = 1.167–5.736], whereas those in the HEAT-like repeat region had a lower risk (P = 0.036, adjusted OR = 0.396, 95% CI = 0.166–0.942). This study confirms a new correlation between NF1 genotype and OPG phenotype in patients with neurofibromatosis type I, and provides novel insights into molecular functions of neurofibromin.
Collapse
Affiliation(s)
- Min Xu
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hui Xiong
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yanfang Han
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Chijun Li
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shaozhen Mai
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Dermatology, The Eighth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhongzhou Huang
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xuechen Ai
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhixuan Guo
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Fanqin Zeng
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Qing Guo
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
213
|
Harsini FM, Chebrolu S, Fuson KL, White MA, Rice AM, Sutton RB. FerA is a Membrane-Associating Four-Helix Bundle Domain in the Ferlin Family of Membrane-Fusion Proteins. Sci Rep 2018; 8:10949. [PMID: 30026467 PMCID: PMC6053371 DOI: 10.1038/s41598-018-29184-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 07/04/2018] [Indexed: 12/15/2022] Open
Abstract
Ferlin proteins participate in such diverse biological events as vesicle fusion in C. elegans, fusion of myoblast membranes to form myotubes, Ca2+-sensing during exocytosis in the hair cells of the inner ear, and Ca2+-dependent membrane repair in skeletal muscle cells. Ferlins are Ca2+-dependent, phospholipid-binding, multi-C2 domain-containing proteins with a single transmembrane helix that spans a vesicle membrane. The overall domain composition of the ferlins resembles the proteins involved in exocytosis; therefore, it is thought that they participate in membrane fusion at some level. But if ferlins do fuse membranes, then they are distinct from other known fusion proteins. Here we show that the central FerA domain from dysferlin, myoferlin, and otoferlin is a novel four-helix bundle fold with its own Ca2+-dependent phospholipid-binding activity. Small-angle X-ray scattering (SAXS), spectroscopic, and thermodynamic analysis of the dysferlin, myoferlin, and otoferlin FerA domains, in addition to clinically-defined dysferlin FerA mutations, suggests that the FerA domain interacts with the membrane and that this interaction is enhanced by the presence of Ca2+.
Collapse
Affiliation(s)
- Faraz M Harsini
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX, 79430-6551, USA
| | - Sukanya Chebrolu
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX, 79430-6551, USA
| | - Kerry L Fuson
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX, 79430-6551, USA
| | - Mark A White
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Anne M Rice
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - R Bryan Sutton
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, TX, 79430-6551, USA. .,Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, 79430-6551, USA.
| |
Collapse
|
214
|
Duan D. Systemic AAV Micro-dystrophin Gene Therapy for Duchenne Muscular Dystrophy. Mol Ther 2018; 26:2337-2356. [PMID: 30093306 PMCID: PMC6171037 DOI: 10.1016/j.ymthe.2018.07.011] [Citation(s) in RCA: 280] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/05/2018] [Accepted: 07/11/2018] [Indexed: 12/23/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal muscle disease caused by dystrophin gene mutation. Conceptually, replacing the mutated gene with a normal one would cure the disease. However, this task has encountered significant challenges due to the enormous size of the gene and the distribution of muscle throughout the body. The former creates a hurdle for viral vector packaging and the latter begs for whole-body therapy. To address these obstacles, investigators have invented the highly abbreviated micro-dystrophin gene and developed body-wide systemic gene transfer with adeno-associated virus (AAV). Numerous microgene configurations and various AAV serotypes have been explored in animal models in many laboratories. Preclinical data suggests that intravascular AAV micro-dystrophin delivery can significantly ameliorate muscle pathology, enhance muscle force, and attenuate dystrophic cardiomyopathy in animals. Against this backdrop, several clinical trials have been initiated to test the safety and tolerability of this promising therapy in DMD patients. While these trials are not powered to reach a conclusion on clinical efficacy, findings will inform the field on the prospects of body-wide DMD therapy with a synthetic micro-dystrophin AAV vector. This review discusses the history, current status, and future directions of systemic AAV micro-dystrophin therapy.
Collapse
Affiliation(s)
- Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA; Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; Department of Neurology, School of Medicine, University of Missouri, Columbia, MO 65212, USA; Department of Bioengineering, University of Missouri, Columbia, MO 65212, USA.
| |
Collapse
|
215
|
Wang RT, Barthelemy F, Martin AS, Douine ED, Eskin A, Lucas A, Lavigne J, Peay H, Khanlou N, Sweeney L, Cantor RM, Miceli MC, Nelson SF. DMD genotype correlations from the Duchenne Registry: Endogenous exon skipping is a factor in prolonged ambulation for individuals with a defined mutation subtype. Hum Mutat 2018; 39:1193-1202. [PMID: 29907980 PMCID: PMC6175390 DOI: 10.1002/humu.23561] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 05/10/2018] [Accepted: 05/31/2018] [Indexed: 01/05/2023]
Abstract
Antisense oligonucleotide (AON)‐mediated exon skipping is an emerging therapeutic for individuals with Duchenne muscular dystrophy (DMD). Skipping of exons adjacent to common exon deletions in DMD using AONs can produce in‐frame transcripts and functional protein. Targeted skipping of DMD exons 8, 44, 45, 50, 51, 52, 53, and 55 is predicted to benefit 47% of affected individuals. We observed a correlation between mutation subgroups and age at loss of ambulation in the Duchenne Registry, a large database of phenotypic and genetic data for DMD (N = 765). Males amenable to exon 44 (N = 74) and exon 8 skipping (N = 18) showed prolonged ambulation compared to other exon skip groups and nonsense mutations (P = 0.035 and P < 0.01, respectively). In particular, exon 45 deletions were associated with prolonged age at loss of ambulation relative to the rest of the exon 44 skip amenable cohort and other DMD mutations. Exon 3–7 deletions also showed prolonged ambulation relative to all other exon 8 skippable mutations. Cultured myotubes from DMD patients with deletions of exons 3–7 or exon 45 showed higher endogenous skipping than other mutations, providing a potential biological rationale for our observations. These results highlight the utility of aggregating phenotypic and genotypic data for rare pediatric diseases to reveal progression differences, identify potentially confounding factors, and probe molecular mechanisms that may affect disease severity.
Collapse
Affiliation(s)
- Richard T Wang
- Department of Human Genetics, David Geffen School of Medicine, University of California ,Los Angeles, California.,Center for Duchenne Muscular Dystrophy, University of California, Los Angeles,Los Angeles, California
| | - Florian Barthelemy
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles,Los Angeles, California.,Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine and College of Letters and Sciences, University of California, Los Angeles, Los Angeles, California
| | - Ann S Martin
- Parent Project Muscular Dystrophy, Hackensack, New Jersey
| | - Emilie D Douine
- Department of Human Genetics, David Geffen School of Medicine, University of California ,Los Angeles, California.,Center for Duchenne Muscular Dystrophy, University of California, Los Angeles,Los Angeles, California
| | - Ascia Eskin
- Department of Human Genetics, David Geffen School of Medicine, University of California ,Los Angeles, California.,Center for Duchenne Muscular Dystrophy, University of California, Los Angeles,Los Angeles, California
| | - Ann Lucas
- Parent Project Muscular Dystrophy, Hackensack, New Jersey
| | | | - Holly Peay
- Parent Project Muscular Dystrophy, Hackensack, New Jersey.,RTI International, Research Triangle Park, North Carolina
| | - Negar Khanlou
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Lee Sweeney
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida
| | - Rita M Cantor
- Department of Human Genetics, David Geffen School of Medicine, University of California ,Los Angeles, California
| | - M Carrie Miceli
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles,Los Angeles, California.,Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine and College of Letters and Sciences, University of California, Los Angeles, Los Angeles, California.,Molecular Biology Institute, University of California, Los Angeles, California, Los Angeles
| | - Stanley F Nelson
- Department of Human Genetics, David Geffen School of Medicine, University of California ,Los Angeles, California.,Center for Duchenne Muscular Dystrophy, University of California, Los Angeles,Los Angeles, California.,Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, California
| |
Collapse
|
216
|
Ma P, Zhang S, Zhang H, Fang S, Dong Y, Zhang Y, Hao W, Wu S, Zhao Y. Comprehensive genetic characteristics of dystrophinopathies in China. Orphanet J Rare Dis 2018; 13:109. [PMID: 29973226 PMCID: PMC6032532 DOI: 10.1186/s13023-018-0853-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/20/2018] [Indexed: 11/10/2022] Open
Abstract
Background Dystrophinopathies are a set of severe and incurable X-linked neuromuscular disorders caused by mutations in the dystrophin gene (DMD). These mutations form a complex spectrum. A national registration network is essential not only to provide more information about the prevalence and natural history of the disease, but also to collect genetic data for analyzing the mutational spectrum. This information is extremely beneficial for basic scientific research, genetic diagnosis, trial planning, clinical care, and gene therapy. Methods We collected data from 1400 patients (1042 patients with confirmed unrelated Duchenne muscular dystrophy [DMD] or Becker muscular dystrophy [BMD]) registered in the Chinese Genetic Disease Registry from March 2012 to August 2017 and analyzed the genetic mutational characteristics of these patients. Results Large deletions were the most frequent type of mutation (72.2%), followed by nonsense mutations (11.9%), exon duplications (8.8%), small deletions (3.0%), splice-site mutations (2.1%), small insertions (1.3%), missense mutations (0.6%), and a combination mutation of a deletion and a duplication (0.1%). Exon 45–50 deletion was the most frequent deletion type, while exon 2 duplication was the most common duplication type. Two deletion hotspots were calculated—one located toward the central part (exon 45–52) of the gene and the other toward the 5’end (exon 8–26). We found no significant difference between hereditary and de novo mutations on deletion hotspots. Nonsense mutations accounted for 62.9% of all small mutations (197 patients). Conclusion We built a comprehensive national dystrophinopathy mutation database in China, which is essential for basic and clinical research in this field. The mutational spectrum and characteristics of this DMD/BMD group were largely consistent with those in previous international DMD/BMD studies, with some differences. Based on our results, about 12% of DMD/BMD patients with nonsense mutations may benefit from stop codon read-through therapy. Additionally, the top three targets for exon-skipping therapy are exon 51 (141, 13.5%), exon 53 (115, 11.0%), and exon 45 (84, 8.0%). Electronic supplementary material The online version of this article (10.1186/s13023-018-0853-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Peipei Ma
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Shu Zhang
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Hao Zhang
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Siying Fang
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Yuru Dong
- Department of Magnetic Resonance, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Yan Zhang
- Department of Precision Medicine Laboratory, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Weiwei Hao
- Department of Precision Medicine Laboratory, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Shiwen Wu
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China.
| | - Yuying Zhao
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China.
| |
Collapse
|
217
|
Tyers L, Davids LM, Wilmshurst JM, Esterhuizen AI. Skin cells for use in an alternate diagnostic method for Duchenne muscular dystrophy. Neuromuscul Disord 2018; 28:553-563. [PMID: 29958823 DOI: 10.1016/j.nmd.2018.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/27/2018] [Accepted: 05/02/2018] [Indexed: 01/08/2023]
Abstract
The importance of molecular diagnosis and identification of disease-associated variants for Duchenne muscular dystrophy (DMD) is evident in the age of gene-based therapies and personalised medicine. Detection of the causative DMD variant and determination of its effects on dystrophin expression is best achieved by analysis of RNA extracted from muscle biopsy material. However, this is not done routinely, as the procedure can be traumatic, especially to young children, and carries risk of complications related to the use of anaesthetic. As skin biopsies are safer and straightforward to perform than muscle biopsies, we investigated the utility of cultured human epidermal melanocytes and dermal fibroblasts as alternative tools for RNA-based diagnosis of DMD. Shallow skin biopsies from 5 boys with genetically confirmed diagnoses of DMD were used to culture fibroblasts and melanocytes. Biopsies were sampled, and tolerated without complications, using local anaesthetic cream. Dystrophin expression in the cultured cells was assessed using immunocytochemical staining, quantitative real-time PCR and cDNA sequencing methodologies. We observed differential expression of the full-length dystrophin muscle transcript, with significantly more robust expression in melanocytes, compared to that in fibroblasts. Our results suggest that cultured skin melanocytes may present an alternative tool for RNA-based genetic diagnosis of DMD.
Collapse
Affiliation(s)
- Lynn Tyers
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town 7935, South Africa.
| | | | - Jo M Wilmshurst
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town 7935, South Africa; Department of Paediatric Neurology and Neurophysiology, Neuroscience Institute, Red Cross War Memorial Children's Hospital, University of Cape Town, Rondebosch, Cape Town 7700, South Africa
| | - Alina I Esterhuizen
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town 7935, South Africa; National Health Laboratory Service, Groote Schuur Hospital, Observatory, Cape Town 7935, South Africa
| |
Collapse
|
218
|
DMD mutation and LTBP4 haplotype do not predict onset of left ventricular dysfunction in Duchenne muscular dystrophy. Cardiol Young 2018; 28:910-915. [PMID: 29766838 PMCID: PMC8018586 DOI: 10.1017/s1047951118000288] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cardiomyopathy develops in >90% of Duchenne muscular dystrophy (DMD) patients by the second decade of life. We assessed the associations between DMD gene mutations, as well as Latent transforming growth factor-beta-binding protein 4 (LTBP4) haplotypes, and age at onset of myocardial dysfunction in DMD. DMD patients with baseline normal left ventricular systolic function and genotyping between 2004 and 2013 were included. Patients were grouped in multiple ways: specific DMD mutation domains, true loss-of-function mutations (group A) versus possible residual gene expression (group B), and LTBP4 haplotype. Age at onset of myocardial dysfunction was the first echocardiogram with an ejection fraction <55% and/or shortening fraction <28%. Of 101 DMD patients, 40 developed cardiomyopathy. There was no difference in age at onset of myocardial dysfunction among DMD genotype mutation domains (13.7±4.8 versus 14.3±1.0 versus 14.3±2.9 versus 13.8±2.5, p=0.97), groups A and B (14.4±2.8 versus 12.1±4.4, p=0.09), or LTBP4 haplotypes (14.5±3.2 versus 13.1±3.2 versus 11.0±2.8, p=0.18). DMD gene mutations involving the hinge 3 region, actin-binding domain, and exons 45-49, as well as the LTBP4 IAAM haplotype, were not associated with age of left ventricular dysfunction onset in DMD.
Collapse
|
219
|
Abstract
PURPOSE OF REVIEW The purpose of this review is to summarize the current and emerging therapies for Duchenne muscular dystrophy (DMD). RECENT FINDINGS Coinciding with new standardized care guidelines, there are a growing number of therapeutic options to treat males with DMD. Treatment of the underlying pathobiology, such as micro-dystrophin gene replacement, exon skipping, stop codon read-through agents, and utrophin modulators showed variable success in animal and human studies. Symptomatic therapies to target muscle ischemia, enhance muscle regeneration, prevent muscle fibrosis, inhibit myostatin, and reduce inflammation are also under investigation. DMD is a complex, heterogeneous degenerative disease. The pharmacological and technological achievements made in recent years, plus timely supportive interventions will likely lead to an improved quality of life for many individuals with DMD.
Collapse
Affiliation(s)
- Megan Crone
- Division of Neurology, Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada. .,Alberta Children's Hospital, 2888 Shaganappi Trail NW, Calgary, Alberta, T3B 6A8, Canada.
| | - Jean K Mah
- Division of Neurology, Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
220
|
Ratio of Creatine Kinase to Alanine Aminotransferase as a Biomarker of Acute Liver Injury in Dystrophinopathy. DISEASE MARKERS 2018; 2018:6484610. [PMID: 30018675 PMCID: PMC6029496 DOI: 10.1155/2018/6484610] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 03/22/2018] [Accepted: 03/28/2018] [Indexed: 12/12/2022]
Abstract
Objective To investigate the ratios of creatine kinase (CK) to aminotransferases as biomarkers of acute liver injury in dystrophinopathy. Methods C57 and mdx (dystrophic) mice were treated with a hepatotoxic reagent D-galactosamine (D-GalN). The degrees of liver and muscle injury were assessed using histological examinations. To examine whether serum CK-adjusted aminotransferase levels could indicate liver status in dystrophic mice, the CK/alanine aminotransferase (ALT) and CK/aspartate aminotransferase (AST) ratios were analyzed. Furthermore, we enrolled 658 male patients with dystrophinopathy and 378 male patients without muscle and liver injury as control, whose serum ALT, AST, and CK levels were examined. Results Animal experiments indicated that D-GalN treatment could induce acute liver injury but not muscle injury. Additionally, D-GalN decreased the CK/ALT and CK/AST ratios in both C57 mice and mdx mice (P < 0.001). However, there was an overlap of the CK/AST ratio between dystrophic mice with and without acute liver injury. In patients with dystrophinopathy, CK-adjusted ALT diminished the variability associated with age, genotype, clinical phenotype, and motor function (P > 0.05). Conclusions CK/ALT is a potential biomarker for the differential evaluation of acute liver injury in dystrophic mice, which highlights the value to further evaluate the practice of CK/ALT in dystrophinopathy patients.
Collapse
|
221
|
Abstract
Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy in childhood. Mutations of the DMD gene destabilize the dystrophin associated glycoprotein complex in the sarcolemma. Ongoing mechanical stress leads to unregulated influx of calcium ions into the sarcoplasm, with activation of proteases, release of proinflammatory cytokines, and mitochondrial dysfunction. Cumulative damage and reparative failure leads to progressive muscle necrosis, fibrosis, and fatty replacement. Although there is presently no cure for DMD, scientific advances have led to many potential disease-modifying treatments, including dystrophin replacement therapies, upregulation of compensatory proteins, anti-inflammatory agents, and other cellular targets. Recently approved therapies include ataluren for stop codon read-through and eteplirsen for exon 51 skipping of eligible individuals. The purpose of this chapter is to summarize the clinical features of DMD, to describe current outcome measures used in clinical studies, and to highlight new emerging therapies for affected individuals.
Collapse
|
222
|
Exon Skipping Therapy Using Phosphorodiamidate Morpholino Oligomers in the mdx52 Mouse Model of Duchenne Muscular Dystrophy. Methods Mol Biol 2018; 1687:123-141. [PMID: 29067660 DOI: 10.1007/978-1-4939-7374-3_9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Exon skipping therapy using synthetic DNA-like molecules called antisense oligonucleotides (ASOs) is a promising therapeutic candidate for overcoming the dystrophin mutation that causes Duchenne muscular dystrophy (DMD). This treatment involves splicing out the frame-disrupting segment of the dystrophin mRNA, which restores the reading frame and produces a truncated yet functional dystrophin protein. Phosphorodiamidate morpholino oligomer (PMO) is the safest ASO for patients among ASOs and has recently been approved under the accelerated approval pathway by the U.S. Food and Drug Administration (FDA) as the first drug for DMD. Here, we describe the methodology and protocol of PMO transfection and evaluation of the exon skipping efficacy in the mdx52 mouse, an exon 52 deletion model of DMD produced by gene targeting. The mdx52 mouse model offers advantages over the mdx mouse, a spontaneous DMD model with a nonsense mutation in exon 23, in terms of the deletion in a hotspot of deletion mutations in DMD patients, the analysis of caveolae and also Dp140 and Dp260, shorter dystrophin isoforms.
Collapse
|
223
|
Abstract
During the past 10 years, antisense oligonucleotide-mediated exon skipping and splice modulation have proven to be powerful tools for correction of mRNA splicing in genetic diseases. In 2016, the US Food and Drug Administration (FDA)-approved Exondys 51 (eteplirsen) and Spinraza (nusinersen), the first exon skipping and exon inclusion drugs, to treat patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA), respectively. The exon skipping of DMD mRNA aims to restore the disrupted reading frame using antisense oligonucleotides (AONs), allowing the production of truncated but partly functional dystrophin proteins, and slow down the progression of the disease. This approach has also been explored in several other genetic disorders, including laminin α2 chain-deficient congenital muscular dystrophy, dysferlin-deficient muscular dystrophy (e.g., Miyoshi myopathy and limb-girdle muscular dystrophy type 2B), sarcoglycanopathy (limb-girdle muscular dystrophy type 2C), and Fukuyama congenital muscular dystrophy. Antisense-mediated exon skipping is also a powerful tool to examine the function of genes and exons. A significant challenge in exon skipping is how to design effective AONs. The mechanism of mRNA splicing is highly complex with many factors involved. The selection of target sites, the length of AONs, the AON chemistry, and the melting temperature versus the RNA strand play important roles. A cocktail of AONs can be employed to skip multiples exons. In this chapter, we discuss the design of effective AONs for exon skipping.
Collapse
|
224
|
Mohammed F, Elshafey A, Al-balool H, Alaboud H, Al Ben Ali M, Baqer A, Bastaki L. Mutation spectrum analysis of Duchenne/Becker muscular dystrophy in 68 families in Kuwait: The era of personalized medicine. PLoS One 2018; 13:e0197205. [PMID: 29847600 PMCID: PMC5976149 DOI: 10.1371/journal.pone.0197205] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 04/27/2018] [Indexed: 11/19/2022] Open
Abstract
Duchenne and Becker muscular dystrophies (DMD/BMD) are X-linked recessive neuromuscular disorders characterized by progressive irreversible muscle weakness and atrophy that affect both skeletal and cardiac muscles. DMD/BMD is caused by mutations in the Dystrophin gene on the X chromosome, leading to the absence of the essential muscle protein Dystrophin in DMD. In BMD, Dystrophin is partially functioning with a shorter protein product. Recent advances in molecular therapies for DMD require precise genetic diagnoses because most therapeutic strategies are mutation-specific. Hence, early diagnosis is crucial to allow appropriate planning for patient care and treatment. In this study, data from DMD/BMD patients who attended the Kuwait Medical Genetic Center during the last 20 years was retrieved from a Kuwait neuromuscular registry and analyzed. We combined multiplex PCR and multiplex ligation-dependent probe amplification (MLPA) with Sanger sequencing to detect Dystrophin gene mutations. A total of 35 different large rearrangements, 2 deletion-insertions (Indels) and 4 substitution mutations were identified in the 68 unrelated families. The deletion and duplication rates were 66.2% and 4.4%, respectively. The analyzed data from our registry revealed that 11 (16%) of the DMD families will benefit from newly introduced therapies (Ataluren and exon 51 skipping). At the time of submitting this paper, two cases have already enrolled in Ataluren (Tranlsarna™) therapy, and one case has been enrolled in exon 51 skipping therapy.
Collapse
Affiliation(s)
- Fawziah Mohammed
- Medical Laboratory Sciences, Faculty of Allied Health Sciences, Kuwait University, Jabriah, Kuwait
- * E-mail:
| | - Alaa Elshafey
- Kuwait Medical Genetic Centre, Ministry of Health, Shouaikh, Kuwait
| | - Haya Al-balool
- Kuwait Medical Genetic Centre, Ministry of Health, Shouaikh, Kuwait
| | - Hayat Alaboud
- Kuwait Medical Genetic Centre, Ministry of Health, Shouaikh, Kuwait
| | | | - Adel Baqer
- Kuwait Medical Genetic Centre, Ministry of Health, Shouaikh, Kuwait
| | - Laila Bastaki
- Kuwait Medical Genetic Centre, Ministry of Health, Shouaikh, Kuwait
| |
Collapse
|
225
|
Liu C, Deng H, Yang C, Li X, Zhu Y, Chen X, Li H, Li S, Cui H, Zhang X, Tan X, Li D, Zhang Z. A resolved discrepancy between multiplex PCR and multiplex ligation-dependent probe amplification by targeted next-generation sequencing discloses a novel partial exonic deletion in the Duchenne muscular dystrophy gene. J Clin Lab Anal 2018; 32:e22575. [PMID: 29802662 DOI: 10.1002/jcla.22575] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 04/25/2018] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The genetic diagnosis of Duchenne muscular dystrophy (DMD) has been complicated by the large size of the gene and its heterogeneous mutational spectrum. Multiplex PCR and multiplex ligation-dependent probe amplification (MLPA) are two well-established mutation screening methods. Here, we applied targeted next-generation sequencing (NGS) to clarify discrepant results between multiplex PCR and MLPA in a Chinese patient with DMD. METHODS MLPA was performed to confirm multiplex PCR results obtained previously. Targeted NGS was then used to analyze the full-length DMD gene including introns. RESULTS Multiplex PCR had previously identified an apparent deletion of exon 43 in the patient with DMD, but current MLPA indicated that exon 43 was present. Targeted NGS to clarify the genetic diagnosis identified a novel mutation, c.6241_c.6290 + 1109del1159insAC, which caused partial deletion of exon 43. This mutation removed the annealing sequence of the exon 43 reverse primer in multiplex PCR but had no influence on the hybridization site of the MLPA probe. Therefore, the discrepancy between the two methods was caused by partial exonic deletion that escaped MLPA detection. CONCLUSION Targeted NGS disclosed a novel partial exonic deletion in the DMD gene as the cause of discrepancy between multiplex PCR and MLPA. Targeted NGS could be used to provide a more accurate genetic diagnosis of DMD, particularly in cases of partial exonic deletions, which will be of benefit in patient management and the identification of disease carriers.
Collapse
Affiliation(s)
- Chang Liu
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Huiting Deng
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Cheng Yang
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Xixi Li
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Yanrong Zhu
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Xiangfa Chen
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Hui Li
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Shuo Li
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Hao Cui
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Xiaoyan Zhang
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Xiaoyue Tan
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| | - Dong Li
- Department of Neurology, Tianjin Children's Hospital, Tianjin, China
| | - Zhujun Zhang
- Department of Pathology, School of Medicine, Nankai University, Tianjin, China
| |
Collapse
|
226
|
Charleston JS, Schnell FJ, Dworzak J, Donoghue C, Lewis S, Chen L, Young GD, Milici AJ, Voss J, DeAlwis U, Wentworth B, Rodino-Klapac LR, Sahenk Z, Frank D, Mendell JR. Eteplirsen treatment for Duchenne muscular dystrophy: Exon skipping and dystrophin production. Neurology 2018; 90:e2146-e2154. [PMID: 29752304 DOI: 10.1212/wnl.0000000000005680] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 03/15/2018] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE To describe the quantification of novel dystrophin production in patients with Duchenne muscular dystrophy (DMD) after long-term treatment with eteplirsen. METHODS Clinical study 202 was an observational, open-label extension of the randomized, controlled study 201 assessing the safety and efficacy of eteplirsen in patients with DMD with a confirmed mutation in the DMD gene amenable to correction by skipping of exon 51. Patients received once-weekly IV doses of eteplirsen 30 or 50 mg/kg. Upper extremity muscle biopsy samples were collected at combined study week 180, blinded, and assessed for dystrophin-related content by Western blot, Bioquant software measurement of dystrophin-associated immunofluorescence intensity, and percent dystrophin-positive fibers (PDPF). Results were contrasted with matched untreated biopsies from patients with DMD. Reverse transcription PCR followed by Sanger sequencing of newly formed slice junctions was used to confirm the mechanism of action of eteplirsen. RESULTS Reverse transcription PCR analysis and sequencing of the newly formed splice junction confirmed that 100% of treated patients displayed the expected skipped exon 51 sequence. In treated patients vs untreated controls, Western blot analysis of dystrophin content demonstrated an 11.6-fold increase (p = 0.007), and PDPF analysis demonstrated a 7.4-fold increase (p < 0.001). The PDPF findings were confirmed in a re-examination of the sample (15.5-fold increase, p < 0.001). Dystrophin immunofluorescence intensity was 2.4-fold greater in treated patients than in untreated controls (p < 0.001). CONCLUSION Taken together, the 4 assays, each based on unique evaluation mechanisms, provided evidence of eteplirsen muscle cell penetration, exon skipping, and induction of novel dystrophin expression. CLASSIFICATION OF EVIDENCE This study provides Class II evidence of the muscle cell penetration, exon skipping, and induction of novel dystrophin expression by eteplirsen, as confirmed by 4 assays.
Collapse
Affiliation(s)
- Jay S Charleston
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO.
| | - Frederick J Schnell
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Johannes Dworzak
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Cas Donoghue
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Sarah Lewis
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Lei Chen
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - G David Young
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Anthony J Milici
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Jon Voss
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Uditha DeAlwis
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Bruce Wentworth
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Louise R Rodino-Klapac
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Zarife Sahenk
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Diane Frank
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| | - Jerry R Mendell
- From Sarepta Therapeutics, Inc (J.S.C., F.J.S., J.D., C.D., J.V., U.D., B.W., D.F.), Cambridge, MA; Nationwide Children's Hospital (S.L., L.C., L.R.R.-K., Z.S., J.R.M.), Columbus, OH; and Flagship Biosciences (G.D.Y., A.J.M.), Westminster, CO
| |
Collapse
|
227
|
Elhawary NA, Jiffri EH, Jambi S, Mufti AH, Dannoun A, Kordi H, Khogeer A, Jiffri OH, Elhawary AN, Tayeb MT. Molecular characterization of exonic rearrangements and frame shifts in the dystrophin gene in Duchenne muscular dystrophy patients in a Saudi community. Hum Genomics 2018; 12:18. [PMID: 29631625 PMCID: PMC5891934 DOI: 10.1186/s40246-018-0152-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 04/02/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND In individuals with Duchenne muscular dystrophy (DMD), exon skipping treatment to restore a wild-type phenotype or correct the frame shift of the mRNA transcript of the dystrophin (DMD) gene are mutation-specific. To explore the molecular characterization of DMD rearrangements and predict the reading frame, we simultaneously screened all 79 DMD gene exons of 45 unrelated male DMD patients using a multiplex ligation-dependent probe amplification (MLPA) assay for deletion/duplication patterns. Multiplex PCR was used to confirm single deletions detected by the MLPA. RESULTS There was an obvious diagnostic delay, with an extremely statistically significant difference between the age at initial symptoms and the age of clinical evaluation of DMD cases (t value, 10.3; 95% confidence interval 5.95-8.80, P < 0.0001); the mean difference between the two groups was 7.4 years. Overall, we identified 147 intragenic rearrangements: 46.3% deletions and 53.7% duplications. Most of the deletions (92.5%) were between exons 44 and 56, with exon 50 being the most frequently involved (19.1%). Eight new rearrangements, including a mixed deletion/duplication and double duplications, were linked to seven cases with DMD. Of all the cases, 17.8% had duplications with no hot spots. In addition, confirmation of the reading frame hypothesis helped account for new DMD rearrangements in this study. We found that 81% of our Saudi patients would potentially benefit from exon skipping, of which 42.9% had a mutation amenable to skipping of exon 51. CONCLUSIONS Our study could generate considerable data on mutational rearrangements that may promote future experimental therapies in Saudi Arabia.
Collapse
Affiliation(s)
- Nasser A Elhawary
- Department of Medical Genetics, Medicine College, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955, Saudi Arabia.
- Department of Molecular Genetics, Faculty of Medicine, Ain Shams University, Cairo, 11566, Egypt.
| | - Essam H Jiffri
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdul-Aziz University, Jeddah, Saudi Arabia
| | - Samira Jambi
- Department of Pediatrics, Al Hada Military Hospital, Al Hada, Saudi Arabia
| | - Ahmad H Mufti
- Department of Medical Genetics, Medicine College, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955, Saudi Arabia
| | - Anas Dannoun
- Department of Medical Genetics, Medicine College, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955, Saudi Arabia
| | - Hassan Kordi
- Department of Medical Genetics, Medicine College, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955, Saudi Arabia
| | - Asim Khogeer
- Department of Plan and Research, General Directorate of Health Affairs, Mecca Region, Ministry of Health, Mecca, Saudi Arabia
| | - Osama H Jiffri
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdul-Aziz University, Jeddah, Saudi Arabia
| | | | - Mohammed T Tayeb
- Department of Medical Genetics, Medicine College, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955, Saudi Arabia
| |
Collapse
|
228
|
Molecular characterization of exonic rearrangements and frame shifts in the dystrophin gene in Duchenne muscular dystrophy patients in a Saudi community. Hum Genomics 2018. [PMID: 29631625 DOI: 10.1186/s40246-018-0152-8]] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In individuals with Duchenne muscular dystrophy (DMD), exon skipping treatment to restore a wild-type phenotype or correct the frame shift of the mRNA transcript of the dystrophin (DMD) gene are mutation-specific. To explore the molecular characterization of DMD rearrangements and predict the reading frame, we simultaneously screened all 79 DMD gene exons of 45 unrelated male DMD patients using a multiplex ligation-dependent probe amplification (MLPA) assay for deletion/duplication patterns. Multiplex PCR was used to confirm single deletions detected by the MLPA. RESULTS There was an obvious diagnostic delay, with an extremely statistically significant difference between the age at initial symptoms and the age of clinical evaluation of DMD cases (t value, 10.3; 95% confidence interval 5.95-8.80, P < 0.0001); the mean difference between the two groups was 7.4 years. Overall, we identified 147 intragenic rearrangements: 46.3% deletions and 53.7% duplications. Most of the deletions (92.5%) were between exons 44 and 56, with exon 50 being the most frequently involved (19.1%). Eight new rearrangements, including a mixed deletion/duplication and double duplications, were linked to seven cases with DMD. Of all the cases, 17.8% had duplications with no hot spots. In addition, confirmation of the reading frame hypothesis helped account for new DMD rearrangements in this study. We found that 81% of our Saudi patients would potentially benefit from exon skipping, of which 42.9% had a mutation amenable to skipping of exon 51. CONCLUSIONS Our study could generate considerable data on mutational rearrangements that may promote future experimental therapies in Saudi Arabia.
Collapse
|
229
|
Zhao HH, Sun XP, Shi MC, Yi YX, Cheng H, Wang XX, Xu QC, Ma HM, Wu HQ, Jin QW, Niu Q. Molecular Analysis-Based Genetic Characterization of a Cohort of Patients with Duchenne and Becker Muscular Dystrophy in Eastern China. Chin Med J (Engl) 2018; 131:770-775. [PMID: 29578119 PMCID: PMC5887734 DOI: 10.4103/0366-6999.228237] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background: Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are common X-linked recessive neuromuscular disorders caused by mutations in dystrophin gene. Multiplex polymerase chain reaction (multiplex PCR) and multiplex ligation-dependent probe amplification (MLPA) are the most common methods for detecting dystrophin gene mutations. This study aimed to contrast the two methods and discern the genetic characterization of patients with DMD/BMD in Eastern China. Methods: We collected 121 probands, 64 mothers of probands, and 15 fetuses in our study. The dystrophin gene was detected by multiplex PCR primarily in 28 probands, and MLPA was used in multiplex PCR-negative cases subsequently. The dystrophin gene of the remaining 93 probands and 62 female potential carriers was tested by MLPA directly. In fetuses, multiplex PCR and MLPA were performed on 4 fetuses and 10 fetuses, respectively. In addition, sequencing was also performed in 4 probands with negative MLPA. Results: We found that 61.98% of the subjects had genetic mutations including deletions (50.41%) and duplications (11.57%). There were 43.75% of mothers as carriers of the mutation. In 15 fetuses, 2 out of 7 male fetuses were found to be unhealthy and 2 out of 8 female fetuses were found to be carriers. Exons 3–26 and 45–52 have the maximum frequency in mutation regions. In the frequency of exons individually, exon 47 and exon 50 were the most common in deleted regions and exons 5, 6, and 7 were found most frequently in duplicated regions. Conclusions: MLPA has better productivity and sensitivity than multiplex PCR. Prenatal diagnosis should be applied in DMD high-risk fetuses to reduce the disease incidence. Furthermore, it is the responsibility of physicians to inform female carriers the importance of prenatal diagnosis.
Collapse
Affiliation(s)
- Hui-Hui Zhao
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xue-Ping Sun
- Department of Gynecology and Obstetrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Ming-Chao Shi
- Department of Neurology, The Affiliated Sir Run Run Hospital of Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yong-Xiang Yi
- Department of Neurology, The Second Hospital of Nanjing, Nanjing, Jiangsu 210003, China
| | - Hong Cheng
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xing-Xia Wang
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Qing-Cheng Xu
- Department of Neurology, Nanjing First Hospital, Nanjing, Jiangsu 210012, China
| | - Hong-Ming Ma
- Department of Biomedical Sciences, Texas Tech University Health Science Center, Texas 79430, USA
| | - Hao-Quan Wu
- Department of Biomedical Sciences, Texas Tech University Health Science Center, Texas 79430, USA
| | - Qing-Wen Jin
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029; Department of Neurology, The Affiliated Sir Run Run Hospital of Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Qi Niu
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| |
Collapse
|
230
|
Traverso M, Assereto S, Baratto S, Iacomino M, Pedemonte M, Diana MC, Ferretti M, Broda P, Minetti C, Gazzerro E, Madia F, Bruno C, Zara F, Fiorillo C. Clinical and molecular consequences of exon 78 deletion in DMD gene. J Hum Genet 2018; 63:761-764. [PMID: 29556034 DOI: 10.1038/s10038-018-0439-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 02/05/2018] [Accepted: 02/19/2018] [Indexed: 01/19/2023]
Abstract
We present a 13-year-old patient with persistent increase of serum Creatine Kinase (CK) and myalgia after exertion. Skeletal muscle biopsy showed marked reduction of dystrophin expression leading to genetic analysis of DMD gene by MLPA, which detected a single deletion of exon 78. To the best of our knowledge, DMD exon 78 deletion has never been described in literature and, according to prediction, it should lead to loss of reading frame in the dystrophin gene. To further assess the actual effect of exon 78 deletion, we analysed cDNA from muscle mRNA. This analysis confirmed the absence of 32 bp of exon 78. Exclusion of exon 78 changes the open reading frame of exon 79 and generate a downstream stop codon, producing a dystrophin protein of 3703 amino acids instead of 3685 amino acids. Albeit loss of reading frame usually leads to protein degradation and severe phenotype, in this case, we demonstrated that deletion of DMD exon 78 can be associated with a functional protein able to bind DGC complex and a very mild phenotype. This study adds a novel deletion in DMD gene in human and helps to define the compliance between maintaining/disrupting the reading frame and clinical form of the disease.
Collapse
Affiliation(s)
| | - Stefania Assereto
- Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | - Serena Baratto
- Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | | | - Marina Pedemonte
- Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | - Maria Cristina Diana
- Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | - Marta Ferretti
- Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | - Paolo Broda
- Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | - Carlo Minetti
- DINOGMI, University of Genoa, Genoa, Italy.,Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | - Elisabetta Gazzerro
- Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | - Francesca Madia
- Laboratory of Neurogenetic and Neuroscience, G. Gaslini Institute, Genoa, Italy
| | - Claudio Bruno
- Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy
| | - Federico Zara
- Laboratory of Neurogenetic and Neuroscience, G. Gaslini Institute, Genoa, Italy
| | - Chiara Fiorillo
- DINOGMI, University of Genoa, Genoa, Italy. .,Paediatric Neurology and Muscular Diseases Unit, University of Genoa and G. Gaslini Institute, Genoa, Italy.
| |
Collapse
|
231
|
Ramos E, Conde JG, Berrios RA, Pardo S, Gómez O, Mas Rodríguez MF. Prevalence and Genetic Profile of Duchene and Becker Muscular Dystrophy in Puerto Rico. J Neuromuscul Dis 2018; 3:261-266. [PMID: 27854217 DOI: 10.3233/jnd-160147] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Duchenne and Becker Muscular Dystrophy (DMD and BMD, respectively), are common forms of inherited muscle disease. Information regarding the epidemiology of these conditions, including genotype, is still sparse. OBJECTIVE To establish the prevalence and genetic profile of DMD and BMD in Puerto Rico. METHODS We collected data from medical records in all Muscular Dystrophy Association (MDA) clinics in Puerto Rico in order to estimate the prevalence of DMD and BMD and to describe the genotypic profile of these patients. Patients selected for data analysis matched "definite", "probable" and "possible" case definitions as established by MD STARnet. RESULTS A total of 141 patients matched the inclusion criteria, with 64.5% and 35.5% being categorized into DMD and BMD, respectively. DMD and BMD prevalence in Puerto Rico was estimated at 5.18 and 2.84 per 100,000 males, respectively. Deletion was the most common form of mutation (66.7%) in the dystrophin gene, with exons in segment 45 to 47 being the most frequently affected. CONCLUSIONS This is the first report of the prevalence and genetic profile characteristics of DMD and BMD in Puerto Rico. Prevalence of DMD was similar to that reported worldwide, while prevalence of BMD was higher. Genetic profile was consistent with that reported in the literature.
Collapse
Affiliation(s)
- Edwardo Ramos
- Department of Physical Medicine, Rehabilitation & Sport Medicine, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - José G Conde
- Biomedical Sciences Graduate Program, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Rafael Arias Berrios
- Department of Physical Medicine, Rehabilitation & Sport Medicine, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Sherly Pardo
- Department of Biochemistry & Pediatrics, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Omar Gómez
- Department of Physical Medicine, Rehabilitation & Sport Medicine, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Manuel F Mas Rodríguez
- Department of Physical Medicine, Rehabilitation & Sport Medicine, University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| |
Collapse
|
232
|
Rodrigues M, Echigoya Y, Fukada SI, Yokota T. Current Translational Research and Murine Models For Duchenne Muscular Dystrophy. J Neuromuscul Dis 2018; 3:29-48. [PMID: 27854202 PMCID: PMC5271422 DOI: 10.3233/jnd-150113] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder characterized by progressive muscle degeneration. Mutations in the DMD gene result in the absence of dystrophin, a protein required for muscle strength and stability. Currently, there is no cure for DMD. Since murine models are relatively easy to genetically manipulate, cost effective, and easily reproducible due to their short generation time, they have helped to elucidate the pathobiology of dystrophin deficiency and to assess therapies for treating DMD. Recently, several murine models have been developed by our group and others to be more representative of the human DMD mutation types and phenotypes. For instance, mdx mice on a DBA/2 genetic background, developed by Fukada et al., have lower regenerative capacity and exhibit very severe phenotype. Cmah-deficient mdx mice display an accelerated disease onset and severe cardiac phenotype due to differences in glycosylation between humans and mice. Other novel murine models include mdx52, which harbors a deletion mutation in exon 52, a hot spot region in humans, and dystrophin/utrophin double-deficient (dko), which displays a severe dystrophic phenotype due the absence of utrophin, a dystrophin homolog. This paper reviews the pathological manifestations and recent therapeutic developments in murine models of DMD such as standard mdx (C57BL/10), mdx on C57BL/6 background (C57BL/6-mdx), mdx52, dystrophin/utrophin double-deficient (dko), mdxβgeo, Dmd-null, humanized DMD (hDMD), mdx on DBA/2 background (DBA/2-mdx), Cmah-mdx, and mdx/mTRKO murine models.
Collapse
Affiliation(s)
- Merryl Rodrigues
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - Yusuke Echigoya
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - So-Ichiro Fukada
- Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada.,Muscular Dystrophy Canada Research Chair, Edmonton, Alberta, Canada
| |
Collapse
|
233
|
Nascimento Osorio A, Medina Cantillo J, Camacho Salas A, Madruga Garrido M, Vilchez Padilla JJ. Consensus on the diagnosis, treatment and follow-up of patients with Duchenne muscular dystrophy. Neurologia 2018. [PMID: 29526319 DOI: 10.1016/j.nrl.2018.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD) is the most common myopathy in children, with a worldwide prevalence of approximately 0.5 cases per 10,000 male births. It is characterised by a progressive muscular weakness manifesting in early childhood, with the subsequent appearance of musculoskeletal, respiratory, and cardiac complications, causing disability, dependence, and premature death. Currently, DMD is mainly managed with multidisciplinary symptomatic treatment, with favourable results in terms of the progression of the disease. It is therefore crucial to establish clear, up-to-date guidelines enabling early detection, appropriate treatment, and monitoring of possible complications. DEVELOPMENT We performed a literature search of the main biomedical databases for articles published in the last 10years in order to obtain an overview of the issues addressed by current guidelines and to identify relevant issues for which no consensus has yet been established. The degree of evidence and level of recommendation of the information obtained were classified and ordered according to the criteria of the American Academy of Neurology. CONCLUSIONS DMD management should be multidisciplinary and adapted to the patient's profile and the stage of clinical progression. In addition to corticotherapy, treatment targeting gastrointestinal, respiratory, cardiac, and orthopaedic problems, as well as physiotherapy, should be provided with a view to improving patients' quality of life. Genetic studies play a key role in the management of the disease, both in detecting cases and potential carriers and in characterising the mutation involved and developing new therapies.
Collapse
Affiliation(s)
- A Nascimento Osorio
- Unidad de Patología Neuromuscular, Servicio de Neurología, Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona, España
| | - J Medina Cantillo
- Servicio de Medicina Física y Rehabilitación, Hospital Sant Joan de Déu Esplugues de Llobregat, Barcelona, España
| | - A Camacho Salas
- Sección de Neurología Infantil, Servicio de Neurología, Hospital Universitario 12 de Octubre, Madrid, España
| | - M Madruga Garrido
- Sección de Neurología Pediátrica, Hospital Universitario Virgen del Rocío, Sevilla, España
| | - J J Vilchez Padilla
- Servicio de Neurología, Hospital Universitario y Politécnico de La Fe, Valencia, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) y Departamento de Medicina, Universidad de Valencia, Valencia, España.
| |
Collapse
|
234
|
Clinical and genetic characterisation of dystrophin-deficient muscular dystrophy in a family of Miniature Poodle dogs. PLoS One 2018; 13:e0193372. [PMID: 29474464 PMCID: PMC5825102 DOI: 10.1371/journal.pone.0193372] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 02/08/2018] [Indexed: 11/19/2022] Open
Abstract
Four full-sibling intact male Miniature Poodles were evaluated at 4–19 months of age. One was clinically normal and three were affected. All affected dogs were reluctant to exercise and had generalised muscle atrophy, a stiff gait and a markedly elevated serum creatine kinase activity. Two affected dogs also showed poor development, learning difficulties and episodes of abnormal behaviour. In these two dogs, investigations into forebrain structural and metabolic diseases were unremarkable; electromyography demonstrated fibrillation potentials and complex repetitive discharges in the infraspinatus, supraspinatus and epaxial muscles. Histopathological, immunohistochemical and immunoblotting analyses of muscle biopsies were consistent with dystrophin-deficient muscular dystrophy. DNA samples were obtained from all four full-sibling male Poodles, a healthy female littermate and the dam, which was clinically normal. Whole genome sequencing of one affected dog revealed a >5 Mb deletion on the X chromosome, encompassing the entire DMD gene. The exact deletion breakpoints could not be experimentally ascertained, but we confirmed that this region was deleted in all affected males, but not in the unaffected dogs. Quantitative polymerase chain reaction confirmed all three affected males were hemizygous for the mutant X chromosome, while the wildtype chromosome was observed in the unaffected male littermate. The female littermate and the dam were both heterozygous for the mutant chromosome. Forty-four Miniature Poodles from the general population were screened for the mutation and were homozygous for the wildtype chromosome. The finding represents a naturally-occurring mutation causing dystrophin-deficient muscular dystrophy in the dog.
Collapse
|
235
|
Willmann R, Buccella F, De Luca A, Grounds MD, Versnel J, Vroom E, Ribeiro D, Ambrosini A, Pavlath G, Porter J, Dziewczapolski G, Dubowitz V, Lochmüller H, Campbell K, Davies K, Roth KA, Clark A, Clementi E, Nagaraju K, Goemans N, Straub V, Klein A, Aartsma-Rus A, Grounds M, Willmann R, Buccella F, van Putten M, Fries M, Sheean M, Tinsley J, Girgenrath M. 227 th ENMC International Workshop:. Neuromuscul Disord 2018; 28:185-192. [DOI: 10.1016/j.nmd.2017.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 11/06/2017] [Indexed: 01/31/2023]
|
236
|
Jiang J, Jiang T, Xu J, Shen J, Gao F. Novel Mutation of the Dystrophin Gene in a Child with Duchenne Muscular Dystrophy. Fetal Pediatr Pathol 2018; 37:1-6. [PMID: 29336709 DOI: 10.1080/15513815.2017.1369201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD) is an X-linked autosomal recessive genetic disorder caused by mutations in DMD gene. Approximately 70% of the mutations are caused by deletions or duplications of DMD exons, while the remaining were minor mutations. CASE REPORT We present a 5-year-old boy with typical clinical features of DMD. A novel mutation was identified as a c.9358_9359insA of DMD gene by next-generation sequencing. This mutation which was origined from mother, generated a frameshift mutation and resulted in abnormal synthesis of protein polypeptide chains. CONCLUSION We demonstrated a novel mutation of DMD gene and expanded the spectrum of mutations causing DMD.
Collapse
Affiliation(s)
- Jingjing Jiang
- a Children's Hospital of Zhejiang University School of Medicine , Hangzhou , P. R. China
| | - Tiejia Jiang
- a Children's Hospital of Zhejiang University School of Medicine , Hangzhou , P. R. China
| | - Jialu Xu
- a Children's Hospital of Zhejiang University School of Medicine , Hangzhou , P. R. China
| | - Jue Shen
- a Children's Hospital of Zhejiang University School of Medicine , Hangzhou , P. R. China
| | - Feng Gao
- a Children's Hospital of Zhejiang University School of Medicine , Hangzhou , P. R. China
| |
Collapse
|
237
|
Shimo T, Hosoki K, Nakatsuji Y, Yokota T, Obika S. A novel human muscle cell model of Duchenne muscular dystrophy created by CRISPR/Cas9 and evaluation of antisense-mediated exon skipping. J Hum Genet 2018; 63:365-375. [PMID: 29339778 DOI: 10.1038/s10038-017-0400-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/13/2017] [Accepted: 11/21/2017] [Indexed: 01/24/2023]
Abstract
Oligonucleotide-mediated splicing modulation is a promising therapeutic approach for Duchenne muscular dystrophy (DMD). Recently, eteplirsen, a phosphorodiamidate morpholino oligomer-based splice-switching oligonucleotide (SSO) targeting DMD exon 51, was approved by the U.S. Food and Drug Administration as the first antisense-based drug for DMD patients. For further exploring SSOs targeting other exons in the DMD gene, the efficacy of exon skipping and protein rescue with each SSO sequence needs evaluations in vitro. However, only a few immortalized muscle cell lines derived from DMD patients have been reported and are available to test the efficacy of exon skipping in vitro. To solve this problem, we generated a novel immortalized DMD muscle cell line from the human rhabdomyosarcoma (RD) cell line. We removed DMD exons 51-57 (~0.3 Mb) in the RD cell line using the CRISPR/Cas9 system. Additionally, in this DMD model cell line, we evaluated the exon 50 skipping activity of previously reported SSOs at both the mRNA and protein levels. CRISPR/Cas9-mediated gene editing of the DMD gene in the RD cell line will allow for assessment of SSOs targeting most of the rare mutations in the DMD gene.
Collapse
Affiliation(s)
- Takenori Shimo
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, 8-31 Medical Science Building, Edmonton, AB, T6G 2H7, Canada
| | - Kana Hosoki
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, 8-31 Medical Science Building, Edmonton, AB, T6G 2H7, Canada
| | - Yusuke Nakatsuji
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, 8-31 Medical Science Building, Edmonton, AB, T6G 2H7, Canada.,Muscular Dystrophy Canada Research Chair, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Satoshi Obika
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
238
|
He Y, Yuan C, Chen L, Lei M, Zellmer L, Huang H, Liao DJ. Transcriptional-Readthrough RNAs Reflect the Phenomenon of "A Gene Contains Gene(s)" or "Gene(s) within a Gene" in the Human Genome, and Thus Are Not Chimeric RNAs. Genes (Basel) 2018; 9:E40. [PMID: 29337901 PMCID: PMC5793191 DOI: 10.3390/genes9010040] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 12/29/2017] [Accepted: 01/07/2018] [Indexed: 02/06/2023] Open
Abstract
Tens of thousands of chimeric RNAs, i.e., RNAs with sequences of two genes, have been identified in human cells. Most of them are formed by two neighboring genes on the same chromosome and are considered to be derived via transcriptional readthrough, but a true readthrough event still awaits more evidence and trans-splicing that joins two transcripts together remains as a possible mechanism. We regard those genomic loci that are transcriptionally read through as unannotated genes, because their transcriptional and posttranscriptional regulations are the same as those of already-annotated genes, including fusion genes formed due to genetic alterations. Therefore, readthrough RNAs and fusion-gene-derived RNAs are not chimeras. Only those two-gene RNAs formed at the RNA level, likely via trans-splicing, without corresponding genes as genomic parents, should be regarded as authentic chimeric RNAs. However, since in human cells, procedural and mechanistic details of trans-splicing have never been disclosed, we doubt the existence of trans-splicing. Therefore, there are probably no authentic chimeras in humans, after readthrough and fusion-gene derived RNAs are all put back into the group of ordinary RNAs. Therefore, it should be further determined whether in human cells all two-neighboring-gene RNAs are derived from transcriptional readthrough and whether trans-splicing truly exists.
Collapse
Affiliation(s)
- Yan He
- Key Lab of Endemic and Ethnic Diseases of the Ministry of Education of China in Guizhou Medical University, Guiyang 550004, Guizhou, China.
| | - Chengfu Yuan
- Department of Biochemistry, China Three Gorges University, Yichang City 443002, Hubei, China.
| | - Lichan Chen
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA.
| | - Mingjuan Lei
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA.
| | - Lucas Zellmer
- Masonic Cancer Center, University of Minnesota, 435 E. River Road, Minneapolis, MN 55455, USA.
| | - Hai Huang
- School of Clinical Laboratory Science, Guizhou Medical University, Guiyang 550004, Guizhou, China.
| | - Dezhong Joshua Liao
- Key Lab of Endemic and Ethnic Diseases of the Ministry of Education of China in Guizhou Medical University, Guiyang 550004, Guizhou, China.
- Department of Pathology, Guizhou Medical University Hospital, Guiyang 550004, Guizhou, China.
| |
Collapse
|
239
|
Ifuku M, Iwabuchi KA, Tanaka M, Lung MSY, Hotta A. Restoration of Dystrophin Protein Expression by Exon Skipping Utilizing CRISPR-Cas9 in Myoblasts Derived from DMD Patient iPS Cells. Methods Mol Biol 2018; 1828:191-217. [PMID: 30171543 DOI: 10.1007/978-1-4939-8651-4_12] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a congenital X-linked disease caused by mutations in the gene encoding the dystrophin protein, which is required for myofiber integrity. Exon skipping therapy is an emerging strategy for restoring the open reading frame of the dystrophin gene to produce functional protein in DMD patients by skipping single or multiple exons. Although antisense oligonucleotides are able to target pre-mRNA for exon skipping, their half-lives are short and any therapeutic benefit is transient. In contrast, genome editing by DNA nucleases, such as the CRISPR-Cas9 system, could offer permanent correction by targeting genomic DNA. Our laboratory previously reported that disrupting the splicing acceptor site in exon 45 by plasmid delivery of the CRISPR-Cas9 system in iPS cells, derived from a DMD patient lacking exon 44, successfully restored dystrophin protein expression in differentiated myoblasts. Herein, we describe an optimized methodology to prepare myoblasts differentiated from iPS cells by mRNA transfection of the CRISPR-Cas9 system to skip exon 45 in myoblasts, and evaluate the restored dystrophin by RT-PCR and Western blotting.
Collapse
Affiliation(s)
- Masataka Ifuku
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Kumiko A Iwabuchi
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Masami Tanaka
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Mandy Siu Yu Lung
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Akitsu Hotta
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan.
| |
Collapse
|
240
|
An Overview of Recent Advances and Clinical Applications of Exon Skipping and Splice Modulation for Muscular Dystrophy and Various Genetic Diseases. Methods Mol Biol 2018; 1828:31-55. [PMID: 30171533 DOI: 10.1007/978-1-4939-8651-4_2] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Exon skipping is a therapeutic approach that is feasible for various genetic diseases and has been studied and developed for over two decades. This approach uses antisense oligonucleotides (AON) to modify the splicing of pre-mRNA to correct the mutation responsible for a disease, or to suppress a particular gene expression, as in allergic diseases. Antisense-mediated exon skipping is most extensively studied in Duchenne muscular dystrophy (DMD) and has developed from in vitro proof-of-concept studies to clinical trials targeting various single exons such as exon 45 (casimersen), exon 53 (NS-065/NCNP-01, golodirsen), and exon 51 (eteplirsen). Eteplirsen (brand name Exondys 51), is the first approved antisense therapy for DMD in the USA, and provides a treatment option for ~14% of all DMD patients, who are amenable to exon 51 skipping. Eteplirsen is granted accelerated approval and marketing authorization by the US Food and Drug Administration (FDA), on the condition that additional postapproval trials show clinical benefit. Permanent exon skipping achieved at the DNA level using clustered regularly interspaced short palindromic repeats (CRISPR) technology holds promise in current preclinical trials for DMD. In hopes of achieving clinical success parallel to DMD, exon skipping and splice modulation are also being studied in other muscular dystrophies, such as Fukuyama congenital muscular dystrophy (FCMD), dysferlinopathy including limb-girdle muscular dystrophy type 2B (LGMD2B), Miyoshi myopathy (MM), and distal anterior compartment myopathy (DMAT), myotonic dystrophy, and merosin-deficient congenital muscular dystrophy type 1A (MDC1A). This chapter also summarizes the development of antisense-mediated exon skipping therapy in diseases such as Usher syndrome, dystrophic epidermolysis bullosa, fibrodysplasia ossificans progressiva (FOP), and allergic diseases.
Collapse
|
241
|
Waldrop MA, Gumienny F, El Husayni S, Frank DE, Weiss RB, Flanigan KM. Low-level dystrophin expression attenuating the dystrophinopathy phenotype. Neuromuscul Disord 2017; 28:116-121. [PMID: 29305136 DOI: 10.1016/j.nmd.2017.11.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 12/29/2022]
Abstract
The reading frame rule suggests that Duchenne muscular dystrophy (DMD) results from DMD mutations causing an out-of-frame transcript, whereas the milder Becker muscular dystrophy results from mutations causing an in-frame transcript. However, predicted nonsense mutations may instead result in altered splicing and an in-frame transcript. Here we report a 10-year-old boy with a predicted nonsense mutation in exon 42 who had a 6-minute walk time of 157% of that of age matched DMD controls, characterized as intermediate muscular dystrophy. RNA sequencing analysis from a muscle biopsy revealed only 6.0-9.8% of DMD transcripts were in-frame, excluding exon 42, and immunoblot demonstrated only 3.2% dystrophin protein expression. Another potential genetic modifier noted was homozygosity for the protective IAAM LTBP4 haplotype. This case suggests that very low levels of DMD exon skipping and dystrophin protein expression may result in amelioration of skeletal muscle weakness, a finding relevant to current dystrophin-restoring therapies.
Collapse
Affiliation(s)
- Megan A Waldrop
- The Center for Gene Therapy, Nationwide Children's Hospital, Columbus, OH 43205, USA; Department of Neurology, The Ohio State University, Columbus, OH 43205, USA; Department of Pediatrics, The Ohio State University, Columbus, OH 43205, USA
| | - Felecia Gumienny
- The Center for Gene Therapy, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Saleh El Husayni
- Department of Translational Development, Sarepta Therapeutics, Inc., Cambridge, MA 02142, USA
| | - Diane E Frank
- Department of Translational Development, Sarepta Therapeutics, Inc., Cambridge, MA 02142, USA
| | - Robert B Weiss
- Department of Human Genetics, The University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Kevin M Flanigan
- The Center for Gene Therapy, Nationwide Children's Hospital, Columbus, OH 43205, USA; Department of Neurology, The Ohio State University, Columbus, OH 43205, USA; Department of Pediatrics, The Ohio State University, Columbus, OH 43205, USA.
| |
Collapse
|
242
|
Meyyazhagan A, Raman NM, Easwaran M, Balasubramanian B, Alagamuthu K, Bhotla HK, Shanmugam S, Inbaraj K, Ramesh Kumar M, Kumar P, Thangamani L, Piramanayagam S, Anand V, Mohd Y, Park S, Teijido O, Carril J, Cacabelos P, Keshavarao S, Cacabelos R. Biochemistry, Cytogenetics and DMD Gene Mutations in South Indian Patients with Duchenne Muscular Dystrophy. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2017.1387381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- A. Meyyazhagan
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, Corunna, Spain
- Genomic Medicine, Continental University Medical School, Huancayo, Peru 3Human Genetics Laboratory, Department of Zoology, School of Life Sciences, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - N. M. Raman
- Department of Biotechnology, Dr. G. R. Damodaran College of Arts and Science, Coimbatore, Tamil Nadu, India
| | - M. Easwaran
- Department of Bioinformatics, Computational Biology Laboratory, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - B. Balasubramanian
- Department of Food Science and Biotechnology, College of Life Science, Sejong University, 209 Neundong-ro, Gwangjin-gu, Seoul-05006, South Korea
| | - K. Alagamuthu
- College of Life Science, Nanjing Normal University, No.1 Wenyuan Road, Qixia District, Nanjing, Jiangsu Province-210023, China
| | - H. Kuchi Bhotla
- Genomic Medicine, Continental University Medical School, Huancayo, Peru 3Human Genetics Laboratory, Department of Zoology, School of Life Sciences, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - S. Shanmugam
- Laboratory of Muscle Biology and Meat Science, Department of Animal Science, Chonbuk National University, 664-14 Duckjin-dong 1Ga, Jeonju City, Jeonbuk 561-756, South Korea
| | - K. Inbaraj
- Department of Conservation Biology, Bharathiar University, Bharathiar 641046, Tamil Nadu, India
| | - M. Ramesh Kumar
- Department of surgery, KMCH Hospital, Coimbatore, Tamil Nadu, India
| | - P. Kumar
- Department of Bioinformatics, Computational Biology Laboratory, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - L. Thangamani
- Department of Bioinformatics, Computational Biology Laboratory, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - S. Piramanayagam
- Department of Bioinformatics, Computational Biology Laboratory, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - V. Anand
- Medical Genetics and Epigenetics Laboratory, Department of Human Genetics and Molecular Biology, School of Life Sciences, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - Y. Mohd
- Medical Genetics and Epigenetics Laboratory, Department of Human Genetics and Molecular Biology, School of Life Sciences, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - S. Park
- Department of Food Science and Biotechnology, College of Life Science, Sejong University, 209 Neundong-ro, Gwangjin-gu, Seoul-05006, South Korea
| | - O. Teijido
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, Corunna, Spain
- Genomic Medicine, Continental University Medical School, Huancayo, Peru 3Human Genetics Laboratory, Department of Zoology, School of Life Sciences, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - J.C. Carril
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, Corunna, Spain
- Genomic Medicine, Continental University Medical School, Huancayo, Peru 3Human Genetics Laboratory, Department of Zoology, School of Life Sciences, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - P. Cacabelos
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, Corunna, Spain
| | - S. Keshavarao
- Genomic Medicine, Continental University Medical School, Huancayo, Peru 3Human Genetics Laboratory, Department of Zoology, School of Life Sciences, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| | - R. Cacabelos
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, Corunna, Spain
- Genomic Medicine, Continental University Medical School, Huancayo, Peru 3Human Genetics Laboratory, Department of Zoology, School of Life Sciences, Bharathiar University, Bharathiar 641 046, Tamil Nadu, India
| |
Collapse
|
243
|
Kyrychenko V, Kyrychenko S, Tiburcy M, Shelton JM, Long C, Schneider JW, Zimmermann WH, Bassel-Duby R, Olson EN. Functional correction of dystrophin actin binding domain mutations by genome editing. JCI Insight 2017; 2:95918. [PMID: 28931764 DOI: 10.1172/jci.insight.95918] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/15/2017] [Indexed: 12/26/2022] Open
Abstract
Dystrophin maintains the integrity of striated muscles by linking the actin cytoskeleton with the cell membrane. Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene (DMD) that result in progressive, debilitating muscle weakness, cardiomyopathy, and a shortened lifespan. Mutations of dystrophin that disrupt the amino-terminal actin-binding domain 1 (ABD-1), encoded by exons 2-8, represent the second-most common cause of DMD. In the present study, we compared three different strategies for CRISPR/Cas9 genome editing to correct mutations in the ABD-1 region of the DMD gene by deleting exons 3-9, 6-9, or 7-11 in human induced pluripotent stem cells (iPSCs) and by assessing the function of iPSC-derived cardiomyocytes. All three exon deletion strategies enabled the expression of truncated dystrophin protein and restoration of cardiomyocyte contractility and calcium transients to varying degrees. We show that deletion of exons 3-9 by genomic editing provides an especially effective means of correcting disease-causing ABD-1 mutations. These findings represent an important step toward eventual correction of common DMD mutations and provide a means of rapidly assessing the expression and function of internally truncated forms of dystrophin-lacking portions of ABD-1.
Collapse
Affiliation(s)
- Viktoriia Kyrychenko
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sergii Kyrychenko
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Malte Tiburcy
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - John M Shelton
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Chengzu Long
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jay W Schneider
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Wolfram-Hubertus Zimmermann
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Rhonda Bassel-Duby
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Eric N Olson
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
244
|
Tsuda T, Fitzgerald KK. Dystrophic Cardiomyopathy: Complex Pathobiological Processes to Generate Clinical Phenotype. J Cardiovasc Dev Dis 2017; 4:jcdd4030014. [PMID: 29367543 PMCID: PMC5715712 DOI: 10.3390/jcdd4030014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/27/2017] [Accepted: 08/30/2017] [Indexed: 02/06/2023] Open
Abstract
Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and X-linked dilated cardiomyopathy (XL-DCM) consist of a unique clinical entity, the dystrophinopathies, which are due to variable mutations in the dystrophin gene. Dilated cardiomyopathy (DCM) is a common complication of dystrophinopathies, but the onset, progression, and severity of heart disease differ among these subgroups. Extensive molecular genetic studies have been conducted to assess genotype-phenotype correlation in DMD, BMD, and XL-DCM to understand the underlying mechanisms of these diseases, but the results are not always conclusive, suggesting the involvement of complex multi-layers of pathological processes that generate the final clinical phenotype. Dystrophin protein is a part of dystrophin-glycoprotein complex (DGC) that is localized in skeletal muscles, myocardium, smooth muscles, and neuronal tissues. Diversity of cardiac phenotype in dystrophinopathies suggests multiple layers of pathogenetic mechanisms in forming dystrophic cardiomyopathy. In this review article, we review the complex molecular interactions involving the pathogenesis of dystrophic cardiomyopathy, including primary gene mutations and loss of structural integrity, secondary cellular responses, and certain epigenetic and other factors that modulate gene expressions. Involvement of epigenetic gene regulation appears to lead to specific cardiac phenotypes in dystrophic hearts.
Collapse
Affiliation(s)
- Takeshi Tsuda
- Nemours Cardiac Center, Nemours/Alfred I. duPont Hospital for Children, Wilmington, 1600 Rockland Rd, DE 19803, USA.
| | - Kristi K Fitzgerald
- Nemours Cardiac Center, Nemours/Alfred I. duPont Hospital for Children, Wilmington, 1600 Rockland Rd, DE 19803, USA.
| |
Collapse
|
245
|
Aartsma-Rus A, Straub V, Hemmings R, Haas M, Schlosser-Weber G, Stoyanova-Beninska V, Mercuri E, Muntoni F, Sepodes B, Vroom E, Balabanov P. Development of Exon Skipping Therapies for Duchenne Muscular Dystrophy: A Critical Review and a Perspective on the Outstanding Issues. Nucleic Acid Ther 2017; 27:251-259. [PMID: 28796573 PMCID: PMC5649120 DOI: 10.1089/nat.2017.0682] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a rare, severe, progressive muscle-wasting disease leading to disability and premature death. Patients lack the muscle membrane-stabilizing protein dystrophin. Antisense oligonucleotide (AON)-mediated exon skipping is a therapeutic approach that aims to induce production of partially functional dystrophins. Recently, an AON targeting exon 51 became the first of its class to be approved by the United States regulators [Food and Drug Administration (FDA)] for the treatment of DMD. A unique aspect of the exon-skipping approach for DMD is that, depending on the size and location of the mutation, different exons need to be skipped. This challenge raises a number of questions regarding the development and regulatory approval of those individual compounds. In this study, we present a perspective on those questions, following a European stakeholder meeting involving academics, regulators, and representatives from industry and patient organizations, and in the light of the most recent scientific and regulatory experience.
Collapse
Affiliation(s)
- Annemieke Aartsma-Rus
- 1 Department of Human Genetics, Leiden University Medical Center , Leiden, the Netherlands .,2 John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University , Newcastle upon Tyne, United Kingdom
| | - Volker Straub
- 2 John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University , Newcastle upon Tyne, United Kingdom
| | - Robert Hemmings
- 3 Medicines and Healthcare Product Regulatory Agency , London, United Kingdom
| | - Manuel Haas
- 4 Central Nervous System and Ophthalmology, Scientific and Regulatory Management Department, Human Medicines Evaluation Division, European Medicines Agency , London, United Kingdom
| | | | | | - Eugenio Mercuri
- 7 Department of Pediatric Neurology, Catholic University , Rome, Italy .,8 Centro Clinico Nemo, Policlinico Gemelli , Rome, Italy
| | - Francesco Muntoni
- 9 Dubowitz Neuromuscular Center, UCL Great Ormond Street Institute of Child Health , London, United Kingdom
| | - Bruno Sepodes
- 10 Faculdade de Farmácia, Universidade de Lisboa , Lisboa, Portugal
| | - Elizabeth Vroom
- 11 United Parent Project Muscular Dystrophy , Amsterdam, the Netherlands
| | - Pavel Balabanov
- 4 Central Nervous System and Ophthalmology, Scientific and Regulatory Management Department, Human Medicines Evaluation Division, European Medicines Agency , London, United Kingdom
| |
Collapse
|
246
|
Gissy JJ, Johnson T, Fox DJ, Kumar A, Ciafaloni E, van Essen AJ, Peay HL, Martin A, Lucas A, Finkel RS. Delayed onset of ambulation in boys with Duchenne muscular dystrophy: Potential use as an endpoint in clinical trials. Neuromuscul Disord 2017; 27:905-910. [PMID: 28739181 DOI: 10.1016/j.nmd.2017.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 05/30/2017] [Accepted: 06/02/2017] [Indexed: 11/17/2022]
Abstract
Individuals with Duchenne muscular dystrophy (DMD) often exhibit delayed motor and cognitive development, including delayed onset of ambulation. Data on age when loss of independent ambulation occurs are well established for DMD; however, age at onset of walking has not been well described. We hypothesize that an effective medication given in early infancy would advance the age when walking is achieved so that it is closer to age-matched norms, and that this discrete event could serve as the primary outcome measure in a clinical trial. This study examined three data sets, Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet); Dutch Natural History Survey (DNHS); and Parent Project Muscular Dystrophy (PPMD). The distribution of onset of ambulation in DMD (mean ± SD) and median age, in months, at the onset of ambulation was 17.3 (±5.5) and 16.0 in MD STARnet, 21.8 (±7.1) and 20.0 in DNHS, and 16.1 (±4.4) and 15 in PPMD. Age of ambulation in these data sets were all significantly later (P <0.001) than the corresponding age for typically developing boys, 12.1 (±1.8). A hypothetical clinical trial study design and power analyses are presented based on these data.
Collapse
Affiliation(s)
- Jacob J Gissy
- University of Central Florida College of Medicine, Orlando, FL, USA
| | - Teresa Johnson
- University of Central Florida College of Medicine, Orlando, FL, USA
| | - Deborah J Fox
- New York State Department of Health, Albany, NY, USA
| | - Anil Kumar
- New York State Department of Health, Albany, NY, USA
| | | | | | - Holly L Peay
- RTI International, Raleigh, NC, USA; Parent Project Muscular Dystrophy, Hackensack, NJ, USA
| | - Ann Martin
- Parent Project Muscular Dystrophy, Hackensack, NJ, USA
| | - Ann Lucas
- Parent Project Muscular Dystrophy, Hackensack, NJ, USA
| | - Richard S Finkel
- University of Central Florida College of Medicine, Orlando, FL, USA; Nemours Children's Hospital, Orlando, FL, USA.
| | | |
Collapse
|
247
|
England J, Loughna S, Rutland CS. Multiple Species Comparison of Cardiac Troponin T and Dystrophin: Unravelling the DNA behind Dilated Cardiomyopathy. J Cardiovasc Dev Dis 2017; 4:E8. [PMID: 29367539 PMCID: PMC5715711 DOI: 10.3390/jcdd4030008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/01/2017] [Accepted: 07/05/2017] [Indexed: 12/14/2022] Open
Abstract
Animals have frequently been used as models for human disorders and mutations. Following advances in genetic testing and treatment options, and the decreasing cost of these technologies in the clinic, mutations in both companion and commercial animals are now being investigated. A recent review highlighted the genes associated with both human and non-human dilated cardiomyopathy. Cardiac troponin T and dystrophin were observed to be associated with both human and turkey (troponin T) and canine (dystrophin) dilated cardiomyopathies. This review gives an overview of the work carried out in cardiac troponin T and dystrophin to date in both human and animal dilated cardiomyopathy.
Collapse
Affiliation(s)
- Jennifer England
- School of Life Sciences, Medical School, Queens Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Siobhan Loughna
- School of Life Sciences, Medical School, Queens Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Catrin Sian Rutland
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire LE12 5RD, UK.
| |
Collapse
|
248
|
Deepha S, Vengalil S, Preethish-Kumar V, Polavarapu K, Nalini A, Gayathri N, Purushottam M. MLPA identification of dystrophin mutations and in silico evaluation of the predicted protein in dystrophinopathy cases from India. BMC MEDICAL GENETICS 2017; 18:67. [PMID: 28610567 PMCID: PMC5470271 DOI: 10.1186/s12881-017-0431-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/31/2017] [Indexed: 11/18/2022]
Abstract
Background Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive disorders caused by mutations in the DMD gene. The aim of this study was to predict the effect of gene mutations on the dystrophin protein and study its impact on clinical phenotype. Methods In this study, 415 clinically diagnosed patients were tested for mutations by Multiplex ligation dependent probe amplification (MLPA). Muscle biopsy was performed in 34 patients with negative MLPA. Phenotype-genotype correlation was done using PROVEAN, hydrophobicity and eDystrophin analysis. We have utilized bioinformatics tools in order to evaluate the observed mutations both at the level of primary as well as secondary structure. Results Mutations were identified in 75.42% cases, of which there were deletions in 91.6% and duplications in 8.30%. As per the reading frame rule, 84.6% out-of frame and 15.3% in-frame mutations were noted. Exon 50 was the most frequently deleted exon and the exon 45–52 region was the hot-spot for deletions in this cohort. There was no correlation noted between age of onset or creatine kinase (CK) values with extent of gene mutation. The PROVEAN analysis showed a deleterious effect in 94.5% cases and a neutral effect in 5.09% cases. Mutations in exon 45–54 (out of frame) and exon 46–54 (in-frame) regions in the central rod domain of dystrophin showed more negative scores compared to other domains in the present study. Hydrophobicity profile analysis showed that the hydrophobic regions I & III were equally affected. Analysis of deletions in hinge III hydrophobic region by the eDystrophin programme also predicted a hybrid repeat seen to be associated with a BMD like disease progression, thus making the hinge III region relatively tolerant to mutations. Conclusions We found that, while the predictions made by the software utilized might have overall significance, the results were not convincing on a case by case basis. This reflects the inadequacy of the currently available tools and also underlines the possible inadequacy of MLPA to detect other minor mutations that might enhance or suppress the effect of the primary mutation in this large gene. Next Generation Sequencing or targeted Sanger sequencing on a case by case basis might improve phenotype- genotype correlation. Electronic supplementary material The online version of this article (doi:10.1186/s12881-017-0431-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sekar Deepha
- Department of Neuropathology, Neuromuscular Laboratory, Bengaluru, Karnataka, India
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Veeramani Preethish-Kumar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Kiran Polavarapu
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Narayanappa Gayathri
- Department of Neuropathology, Neuromuscular Laboratory, Bengaluru, Karnataka, India
| | - Meera Purushottam
- Molecular Genetics Laboratory, Neurobiology Research Centre, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, 560029, Karnataka, India.
| |
Collapse
|
249
|
Normal and altered pre-mRNA processing in the DMD gene. Hum Genet 2017; 136:1155-1172. [DOI: 10.1007/s00439-017-1820-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/02/2017] [Indexed: 12/11/2022]
|
250
|
Wang M, Wu B, Tucker JD, Lu P, Lu Q. A combinatorial library of triazine-cored polymeric vectors for pDNA delivery in vitro and in vivo. J Mater Chem B 2017; 5:3907-3918. [PMID: 32264252 DOI: 10.1039/c6tb03311c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A set of triazine-cored cationic amphiphilic polymers (TAPs) composed of low molecular weight (Mw) polyethylenimine (LPEI, B) and amphiphilic Jeffamine (A) were prepared with controllable composition and molecular size, and further characterized for plasmid DNA (pDNA) delivery both in vitro and in vivo. These new polymers condensed pDNA efficiently at a polymer/pDNA weight ratio of 5 with particle sizes below 200 nm. The introduction of Jeffamine in the polymers significantly improved the cellular uptake of pDNA, but without increasing its toxicity compared with the parent LPEI. The best formulation resulted in 6- and 29-fold transfection efficiencies of PEI 25k in vitro and in vivo in mdx mice, respectively. Higher transfection efficiency was achieved with more lipophilic A1/A3-based polymers in vitro, with 1A11B3 and 1A12B3 showing the greatest delivery performance. However, the lipophilicity of the TAPs is less critical in vivo as the less lipophilic A2/A4 constructed TAPs also performed similarly well as the more lipophilic A1/A3 constructed ones. In addition, a synergistic effect of LPEI and Jeffamine via chemical conjugation for the delivery of pDNA was revealed in transfection efficiency. These results indicate that the appropriate positive surface and particle size of polymer/pDNA complex and the composition and hydrophilic-lipophilic balance (HLB) of polymers are crucial for effective delivery, although intricate matching exists between A and B in the TAP composition. Triazine-cored cationic amphiphilic polymers are safe and potentially effective carriers for gene/drug delivery.
Collapse
Affiliation(s)
- Mingxing Wang
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Cannon Research Center, Carolinas Medical Center, 1000 Blythe Blvd., Charlotte, NC 28231, USA.
| | | | | | | | | |
Collapse
|