401
|
Abstract
INTRODUCTION We carried out a population-based study of dystrophin mutations in patients followed by members of the Canadian Paediatric Neuromuscular Group (CPNG) over a ten-year period. OBJECTIVES We aimed to describe the changes in diagnostic testing for dystrophinopathy and to determine the frequency of dystrophin mutations from 2000 to 2009. METHODS De-identified data containing the clinical phenotypes, diagnostic methods, and mutational reports from dystrophinopathy patients followed by CPNG centres from January 2000 to December 2009 were analyzed using descriptive statistics. RESULTS 773 patients had a confirmed diagnosis of dystrophinopathy based on genetic testing (97%), muscle biopsy (2%), or family history (1%). 573 (74%) had complete deletion/duplication analysis of all 79 exons or whole gene sequencing, resulting in 366 (64%) deletions, 64 (11%) duplications, and 143 (25%) point mutations. The percentage of patients who were diagnosed using currently accepted genetic testing methods varied across Canada, with a mean of 63% (SD 23). 246 (43%) mutations involved exons 45 to 53. The top ten deletions (n=147, 26%) were exons 45-47, 45-48, 45, 45-50, 45-55, 51, 45-49, 45-52, 49-50, and 46-47. 169 (29%) mutations involved exons 2 to 20. The most common duplications (n=29, 5.1%) were exons 2, 2-7, 2-17, 3-7, 8-11, 10, 10-11, and 12. CONCLUSION This is the most comprehensive report of dystrophin mutations in Canada. Consensus guidelines regarding the diagnostic approach to dystrophinopathy will hopefully reduce the geographical variation in mutation detection rates in the coming decade.
Collapse
|
402
|
Nakano S, Ozasa S, Yoshioka K, Fujii I, Mitsui K, Nomura K, Kosuge H, Endo F, Matsukura M, Kimura S. Exon-skipping events in candidates for clinical trials of morpholino. Pediatr Int 2011; 53:524-9. [PMID: 21342350 DOI: 10.1111/j.1442-200x.2011.03330.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are caused by abnormalities in the DMD gene. The majority of DMD patients have out-of-frame deletion(s), which disrupt the reading frame; while some cases of DMD are caused by duplication or nonsense mutation(s). Most patients with BMD have in-frame deletion(s), which preserve the reading frame. The phenotype of BMD is generally milder than that of DMD. Antisense morpholino-mediated exon skipping, which changes out-of-frame deletions to in-frame deletions, is a promising therapeutic approach for DMD. It is necessary, however, to confirm the exon-skipping event in cells of DMD patients before the clinical trial. METHODS Fibroblasts isolated from four DMD patients were induced to differentiate into the myogenic lineage by infection with Ad.CAGMyoD. The cells were then transfected with two types of morpholino. The exon-skipping event was analyzed on reverse transcription-polymerase chain reaction. RESULTS Morpholino B30, which is located at the splicing enhancer of exon 51 of the DMD gene, yielded the desired exon 51-skipping event in all deletion patterns of cells tested. Morpholino I25, which is located at the exon donor, induced two different exon-skipping patterns, which are total or partial exon 51-skipping events. According to the sequence analysis, the unexpected unskipped regions were the 95 bp section and the 188 bp section of exon 51, showing that the cryptic splicing donor was newly produced with I25. Unfortunately, these cryptic splicing donors gave rise to out-of-frame patterns. Based on these in vitro results, B30 would presumably be an effective therapy. Interestingly, the cocktail of B30 and I25 appeared to yield a more efficient exon 51-skipping event. CONCLUSION An in vitro system was developed that could easily screen the effectiveness of antisense sequences and identify good candidates for therapy with morpholino.
Collapse
Affiliation(s)
- Shiho Nakano
- Department of Child Development Pediatrics, Kumamoto University Graduate School, Kumamoto, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
403
|
Boone PM, Wiszniewski W, Lupski JR. Genomic medicine and neurological disease. Hum Genet 2011; 130:103-21. [PMID: 21594611 PMCID: PMC3133694 DOI: 10.1007/s00439-011-1001-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 04/27/2011] [Indexed: 12/11/2022]
Abstract
"Genomic medicine" refers to the diagnosis, optimized management, and treatment of disease--as well as screening, counseling, and disease gene identification--in the context of information provided by an individual patient's personal genome. Genomic medicine, to some extent synonymous with "personalized medicine," has been made possible by recent advances in genome technologies. Genomic medicine represents a new approach to health care and disease management that attempts to optimize the care of a patient based upon information gleaned from his or her personal genome sequence. In this review, we describe recent progress in genomic medicine as it relates to neurological disease. Many neurological disorders either segregate as Mendelian phenotypes or occur sporadically in association with a new mutation in a single gene. Heritability also contributes to other neurological conditions that appear to exhibit more complex genetics. In addition to discussing current knowledge in this field, we offer suggestions for maximizing the utility of genomic information in clinical practice as the field of genomic medicine unfolds.
Collapse
Affiliation(s)
- Philip M Boone
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | |
Collapse
|
404
|
Fine DM, Shin JH, Yue Y, Volkmann D, Leach SB, Smith BF, McIntosh M, Duan D. Age-matched comparison reveals early electrocardiography and echocardiography changes in dystrophin-deficient dogs. Neuromuscul Disord 2011; 21:453-61. [PMID: 21570848 PMCID: PMC3298689 DOI: 10.1016/j.nmd.2011.03.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 03/02/2011] [Accepted: 03/28/2011] [Indexed: 01/09/2023]
Abstract
The absence of dystrophin in the heart leads to Duchenne cardiomyopathy. Dystrophin-deficient dogs represent a critical model to translate novel therapies developed in mice to humans. Unfortunately, little is known about cardiophysiology changes in these dogs. We performed prospective electrocardiographic and echocardiographic examinations at 3, 6 and 12 months of age in four normal and three affected dogs obtained from the same litter. Affected dogs showed growth retardation and serum creatine kinase elevation. Necropsy confirmed cardiac dystrophin deficiency and histopathology. Q/R ratio elevation and diastolic left ventricular (LV) internal diameter reduction were the most consistent findings in affected dogs at all ages. At 6 and 12 months, dystrophic dogs also showed significant reduction of PR intervals, LV end diastolic/systolic volumes and systolic LV internal diameters. Epicardial and endocardial slope times were significantly reduced in affected dogs at 12 months. These results establish the baseline for evaluating experimental therapies in the future.
Collapse
Affiliation(s)
- Deborah M. Fine
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, The University of Missouri, Columbia, MO, USA
| | - Jin-Hong Shin
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO, USA
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO, USA
| | - Dietrich Volkmann
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, The University of Missouri, Columbia, MO, USA
| | - Stacey B. Leach
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, The University of Missouri, Columbia, MO, USA
| | - Bruce F. Smith
- Scott-Ritchey Research Center and the Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - Mark McIntosh
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO, USA
| |
Collapse
|
405
|
Rani AQ, Malueka RG, Sasongko TH, Awano H, Lee T, Yagi M, Zilfalil BA, Salmi ABR, Takeshima Y, Zabidi-Hussin ZAMH, Matsuo M. Two closely spaced nonsense mutations in the DMD gene in a Malaysian family. Mol Genet Metab 2011; 103:303-4. [PMID: 21514860 DOI: 10.1016/j.ymgme.2011.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 04/02/2011] [Accepted: 04/02/2011] [Indexed: 12/31/2022]
Abstract
In Duchenne muscular dystrophy (DMD), identification of one nonsense mutation in the DMD gene has been considered an endpoint of genetic diagnosis. Here, we identified two closely spaced nonsense mutations in the DMD gene. In a Malaysian DMD patient two nonsense mutations (p.234S>X and p.249Q>X, respectively) were identified within exon 8. The proband's mother carried both mutations on one allele. Multiple mutations may explain the occasional discrepancies between genotype and phenotype in dystrophinopathy.
Collapse
Affiliation(s)
- Abdul Qawee Rani
- Human Genome Center, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
406
|
van Putten M, Aartsma-Rus A. Opportunities and challenges for the development of antisense treatment in neuromuscular disorders. Expert Opin Biol Ther 2011; 11:1025-37. [PMID: 21510827 DOI: 10.1517/14712598.2011.579098] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
INTRODUCTION Neuromuscular disorders are diseases of the musculature and/or the nervous system, generally leading to loss of muscle function. They are a frequent cause of disability and treatment options are often only symptomatic. Interestingly, for a number of neuromuscular disorders the application of antisense oligonucleotides has therapeutic potential. AREAS COVERED The authors describe how this approach is exploited for different neuromuscular diseases, focusing on literature published in the past 10 years. For each disease the opportunities of this approach, the state of the art, and current challenges are described. EXPERT OPINION A lot of progress has been made in the development of antisense-mediated approaches during recent years and they may become clinically applicable in the near future.
Collapse
Affiliation(s)
- Maaike van Putten
- Leiden University Medical Center, Department of Human Genetics, The Netherlands
| | | |
Collapse
|
407
|
Goemans NM, Tulinius M, van den Akker JT, Burm BE, Ekhart PF, Heuvelmans N, Holling T, Janson AA, Platenburg GJ, Sipkens JA, Sitsen JMA, Aartsma-Rus A, van Ommen GJB, Buyse G, Darin N, Verschuuren JJ, Campion GV, de Kimpe SJ, van Deutekom JC. Systemic administration of PRO051 in Duchenne's muscular dystrophy. N Engl J Med 2011; 364:1513-22. [PMID: 21428760 DOI: 10.1056/nejmoa1011367] [Citation(s) in RCA: 511] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Local intramuscular administration of the antisense oligonucleotide PRO051 in patients with Duchenne's muscular dystrophy with relevant mutations was previously reported to induce the skipping of exon 51 during pre-messenger RNA splicing of the dystrophin gene and to facilitate new dystrophin expression in muscle-fiber membranes. The present phase 1-2a study aimed to assess the safety, pharmacokinetics, and molecular and clinical effects of systemically administered PRO051. METHODS We administered weekly abdominal subcutaneous injections of PRO051 for 5 weeks in 12 patients, with each of four possible doses (0.5, 2.0, 4.0, and 6.0 mg per kilogram of body weight) given to 3 patients. Changes in RNA splicing and protein levels in the tibialis anterior muscle were assessed at two time points. All patients subsequently entered a 12-week open-label extension phase, during which they all received PRO051 at a dose of 6.0 mg per kilogram per week. Safety, pharmacokinetics, serum creatine kinase levels, and muscle strength and function were assessed. RESULTS The most common adverse events were irritation at the administration site and, during the extension phase, mild and variable proteinuria and increased urinary α(1)-microglobulin levels; there were no serious adverse events. The mean terminal half-life of PRO051 in the circulation was 29 days. PRO051 induced detectable, specific exon-51 skipping at doses of 2.0 mg or more per kilogram. New dystrophin expression was observed between approximately 60% and 100% of muscle fibers in 10 of the 12 patients, as measured on post-treatment biopsy, which increased in a dose-dependent manner to up to 15.6% of the expression in healthy muscle. After the 12-week extension phase, there was a mean (±SD) improvement of 35.2±28.7 m (from the baseline of 384±121 m) on the 6-minute walk test. CONCLUSIONS Systemically administered PRO051 showed dose-dependent molecular efficacy in patients with Duchenne's muscular dystrophy, with a modest improvement in the 6-minute walk test after 12 weeks of extended treatment. (Funded by Prosensa Therapeutics; Netherlands National Trial Register number, NTR1241.).
Collapse
Affiliation(s)
- Nathalie M Goemans
- Department of Pediatric Neurology, University Hospitals Leuven, Leuven, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
408
|
Kemaladewi DU, Hoogaars WMH, van Heiningen SH, Terlouw S, de Gorter DJJ, den Dunnen JT, van Ommen GJB, Aartsma-Rus A, ten Dijke P, 't Hoen PAC. Dual exon skipping in myostatin and dystrophin for Duchenne muscular dystrophy. BMC Med Genomics 2011; 4:36. [PMID: 21507246 PMCID: PMC3107769 DOI: 10.1186/1755-8794-4-36] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Accepted: 04/20/2011] [Indexed: 12/26/2022] Open
Abstract
Background Myostatin is a potent muscle growth inhibitor that belongs to the Transforming Growth Factor-β (TGF-β) family. Mutations leading to non functional myostatin have been associated with hypermuscularity in several organisms. By contrast, Duchenne muscular dystrophy (DMD) is characterized by a loss of muscle fibers and impaired regeneration. In this study, we aim to knockdown myostatin by means of exon skipping, a technique which has been successfully applied to reframe the genetic defect of dystrophin gene in DMD patients. Methods We targeted myostatin exon 2 using antisense oligonucleotides (AON) in healthy and DMD-derived myotubes cultures. We assessed the exon skipping level, transcriptional expression of myostatin and its target genes, and combined myostatin and several dystrophin AONs. These AONs were also applied in the mdx mice models via intramuscular injections. Results Myostatin AON induced exon 2 skipping in cell cultures and to a lower extent in the mdx mice. It was accompanied by decrease in myostatin mRNA and enhanced MYOG and MYF5 expression. Furthermore, combination of myostatin and dystrophin AONs induced simultaneous skipping of both genes. Conclusions We conclude that two AONs can be used to target two different genes, MSTN and DMD, in a straightforward manner. Targeting multiple ligands of TGF-beta family will be more promising as adjuvant therapies for DMD.
Collapse
Affiliation(s)
- Dwi U Kemaladewi
- Center for Human and Clinical Genetics, Leiden University Medical Center, Postzone S4-P, PO Box 9600, Leiden, 2300RC, the Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
409
|
Current status of pharmaceutical and genetic therapeutic approaches to treat DMD. Mol Ther 2011; 19:830-40. [PMID: 21468001 DOI: 10.1038/mt.2011.59] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic disease affecting about one in every 3,500 boys. This X-linked pathology is due to the absence of dystrophin in muscle fibers. This lack of dystrophin leads to the progressive muscle degeneration that is often responsible for the death of the DMD patients during the third decade of their life. There are currently no curative treatments for this disease but different therapeutic approaches are being studied. Gene therapy consists of introducing a transgene coding for full-length or a truncated version of dystrophin complementary DNA (cDNA) in muscles, whereas pharmaceutical therapy includes the use of chemical/biochemical substances to restore dystrophin expression or alleviate the DMD phenotype. Over the past years, many potential drugs were explored. This led to several clinical trials for gentamicin and ataluren (PTC124) allowing stop codon read-through. An alternative approach is to induce the expression of an internally deleted, partially functional dystrophin protein through exon skipping. The vectors and the methods used in gene therapy have been continually improving in order to obtain greater encapsidation capacity and better transduction efficiency. The most promising experimental approaches using pharmaceutical and gene therapies are reviewed in this article.
Collapse
|
410
|
Shin JH, Nitahara-Kasahara Y, Hayashita-Kinoh H, Ohshima-Hosoyama S, Kinoshita K, Chiyo T, Okada H, Okada T, Takeda S. Improvement of cardiac fibrosis in dystrophic mice by rAAV9-mediated microdystrophin transduction. Gene Ther 2011; 18:910-9. [PMID: 21451578 DOI: 10.1038/gt.2011.36] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Duchenne muscular dystrophy (DMD) is the most common form of the progressive muscular dystrophies characterized by defects of the dystrophin gene. Although primarily characterized by degeneration of the limb muscles, cardiomyopathy is a major cause of death. Therefore, the development of curative modalities such as gene therapy is imperative. We evaluated the cardiomyopathic features of mdx mice to observe improvements in response to intravenous administration of recombinant adeno-associated virus (AAV) type 9 encoding microdystrophin. The myocardium was extensively transduced with microdystrophin to significantly prevent the development of fibrosis, and expression persisted for the duration of the study. Intraventricular conduction patterns, such as the QRS complex duration and S/R ratio in electrocardiography, were also corrected, indicating that the transduced microdystrophin has a protective effect on the dystrophin-deficient myocardium. Furthermore, BNP and ANP levels were reduced to normal, suggesting the absence of cardiac dysfunction. In aged mice, prevention of ectopic beats as well as echocardiographic amelioration was also demonstrated with improved exercise performance. These findings indicate that AAV-mediated cardiac transduction with microdystrophin might be a promising therapeutic strategy for the treatment of dystrophin-deficient cardiomyopathy.
Collapse
Affiliation(s)
- J-H Shin
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
411
|
Wilton SD, Fletcher S. Novel compounds for the treatment of Duchenne muscular dystrophy: emerging therapeutic agents. APPLICATION OF CLINICAL GENETICS 2011; 4:29-44. [PMID: 23776365 PMCID: PMC3681176 DOI: 10.2147/tacg.s8762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The identification of dystrophin and the causative role of mutations in this gene in Duchenne and Becker muscular dystrophies (D/BMD) was expected to lead to timely development of effective therapies. Despite over 20 years of research, corticosteroids remain the only available pharmacological treatment for DMD, although significant benefits and extended life have resulted from advances in the clinical care and management of DMD individuals. Effective treatment of DMD will require dystrophin restitution in skeletal, cardiac, and smooth muscles and nonmuscle tissues; however, modulation of muscle loss and regeneration has the potential to play an important role in altering the natural history of DMD, particularly in combination with other treatments. Emerging biological, molecular, and small molecule therapeutics are showing promise in ameliorating this devastating disease, and it is anticipated that regulatory environments will need to display some flexibility in order to accommodate the new treatment paradigms.
Collapse
Affiliation(s)
- Steve D Wilton
- Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Crawley, Perth, WA, Australia
| | | |
Collapse
|
412
|
Abstract
A milestone of molecular medicine is the identification of dystrophin gene mutation as the cause of Duchenne muscular dystrophy (DMD). Over the last 2 decades, major advances in dystrophin biology and gene delivery technology have created an opportunity to treat DMD with gene therapy. Remarkable success has been achieved in treating dystrophic mice. Several gene therapy strategies, including plasmid transfer, exon skipping, and adeno-associated virus-mediated microdystrophin therapy, have entered clinical trials. However, therapeutic benefit has not been realized in DMD patients. Bridging the gap between mice and humans is no doubt the most pressing issue facing DMD gene therapy now. In contrast to mice, dystrophin-deficient dogs are genetically and phenotypically similar to human patients. Preliminary gene therapy studies in the canine model may offer critical insights that cannot be obtained from murine studies. It is clear that the canine DMD model may represent an important link between mice and humans. Unfortunately, our current knowledge of dystrophic dogs is limited, and the full picture of disease progression remains to be clearly defined. We also lack rigorous outcome measures (such as in situ force measurement) to monitor therapeutic efficacy in dystrophic dogs. Undoubtedly, maintaining a dystrophic dog colony is technically demanding, and the cost of dog studies cannot be underestimated. A carefully coordinated effort from the entire DMD community is needed to make the best use of the precious dog resource. Successful DMD gene therapy may depend on valid translational studies in dystrophin-deficient dogs.
Collapse
Affiliation(s)
- Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA
| |
Collapse
|
413
|
Baskin B, Gibson WT, Ray PN. Duchenne muscular dystrophy caused by a complex rearrangement between intron 43 of the DMD gene and chromosome 4. Neuromuscul Disord 2011; 21:178-82. [DOI: 10.1016/j.nmd.2010.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 11/15/2010] [Indexed: 10/18/2022]
|
414
|
An intronic LINE-1 element insertion in the dystrophin gene aborts dystrophin expression and results in Duchenne-like muscular dystrophy in the corgi breed. J Transl Med 2011; 91:216-31. [PMID: 20714321 PMCID: PMC2999660 DOI: 10.1038/labinvest.2010.146] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a dystrophin-deficient lethal muscle disease. To date, the catastrophic muscle wasting phenotype has only been seen in dystrophin-deficient humans and dogs. Although Duchenne-like symptoms have been observed in more than a dozen dog breeds, the mutation is often not known and research colonies are rarely established. Here, we report an independent canine DMD model originally derived from the Pembroke Welsh corgi breed. The affected dogs presented clinical signs of muscular dystrophy. Immunostaining revealed the absence of dystrophin and upregulation of utrophin. Histopathologic examination showed variable fiber size, central nucleation, calcification, fibrosis, neutrophil and macrophage infiltration and cardiac focal vacuolar degeneration. Carrier dogs also displayed mild myopathy. The mutation was identified as a long interspersed repetitive element-1 (LINE-1) insertion in intron 13, which introduced a new exon containing an in-frame stop codon. Similar mutations have been seen in human patients. A colony was generated by crossing carrier females with normal males. Affected puppies had a normal birth weight but they experienced a striking growth delay in the first 5 days. In summary, the new corgi DMD model offers an excellent opportunity to study DMD pathogenesis and to develop novel therapies.
Collapse
|
415
|
Veerapandiyan A, Shashi V, Jiang YH, Gallentine WB, Schoch K, Smith EC. Pseudometabolic presentation of dystrophinopathy due to a missense mutation. Muscle Nerve 2011; 42:975-9. [PMID: 21104870 DOI: 10.1002/mus.21823] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Exercise intolerance with myalgia, muscle stiffness, and recurrent rhabdomyolysis due to mutations in the DMD gene can mimic metabolic myopathies leading to delayed or inaccurate diagnoses. In this retrospective chart review, we report 3 unrelated boys with exertional myalgia, muscle stiffness, myoglobinuria, and normal neurological examination due to an identical point mutation in the DMD gene: a hemizygous T-to-C change in exon 15 (c.1724T>C) resulting in an amino acid substitution of leucine to proline at codon 575. Two of the 3 boys had normal dystrophin immunostaining and Western blot analysis in muscle. This missense mutation has been reported twice before, with at least 1 patient exhibiting rhabdomyolysis. Our report, however, is the first to describe in detail the clinical findings associated with this specific mutation. Further studies and clinical reports are needed to better understand the pathogenicity of the mutation.
Collapse
Affiliation(s)
- Aravindhan Veerapandiyan
- Swami Clinic, Jayam Diabetic Center, Nalladai Road, Sembanarkoil, Nagai Dt., Tamilnadu 609309, India
| | | | | | | | | | | |
Collapse
|
416
|
|
417
|
Rimessi P, Fabris M, Bovolenta M, Bassi E, Falzarano S, Gualandi F, Rapezzi C, Coccolo F, Perrone D, Medici A, Ferlini A. Antisense modulation of both exonic and intronic splicing motifs induces skipping of a DMD pseudo-exon responsible for x-linked dilated cardiomyopathy. Hum Gene Ther 2010; 21:1137-46. [PMID: 20486769 DOI: 10.1089/hum.2010.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Antisense-mediated exon skipping has proven to be efficacious for subsets of Duchenne muscular dystrophy mutations. This approach is based on targeting specific splicing motifs that interfere with the spliceosome assembly by steric hindrance. Proper exon recognition by the splicing machinery is thought to depend on exonic splicing enhancer sequences, often characterized by purine-rich stretches, representing potential targets for antisense-mediated exon skipping. We identified and functionally characterized two purine-rich regions located within dystrophin intron 11 and involved in splicing regulation of a pseudo-exon. A functional role for these sequences was suggested by a pure intronic DMD deletion causing X-linked dilated cardiomyopathy through the prevalent cardiac incorporation of the aberrant pseudo-exon, marked as Alu-exon, into the dystrophin transcript. The first splicing sequence is contained within the pseudo-exon, whereas the second is localized within its 3' intron. We demonstrated that the two sequences actually behave as splicing enhancers in cell-free splicing assays because their deletion strongly interferes with the pseudo-exon inclusion. Cell-free results were then confirmed in myogenic cells derived from the patient with X-linked dilated cardiomyopathy, by targeting the identified motifs with antisense molecules and obtaining a reduction in dystrophin pseudo-exon recognition. The splicing motifs identified could represent target sequences for a personalized molecular therapy in this particular DMD mutation. Our results demonstrated for the first time the role of intronic splicing sequences in antisense modulation with implications in exon skipping-mediated therapeutic approaches.
Collapse
Affiliation(s)
- Paola Rimessi
- Department of Experimental and Diagnostic Medicine, University of Ferrara, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
418
|
Aartsma-Rus A, den Dunnen JT, van Ommen GJB. New insights in gene-derived therapy: the example of Duchenne muscular dystrophy. Ann N Y Acad Sci 2010; 1214:199-212. [PMID: 21121926 DOI: 10.1111/j.1749-6632.2010.05836.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The two therapeutic approaches currently most advanced in clinical trials for Duchenne muscular dystrophy are antisense-mediated exon skipping and forced read-through of premature stop codons. Interestingly, these approaches target the gene product rather than the gene itself. This review will explain the rationale and current state of affairs of these approaches and will then discuss how these gene-derived therapies might also be applicable to other diseases.
Collapse
Affiliation(s)
- Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands.
| | | | | |
Collapse
|
419
|
Aoki Y, Nakamura A, Yokota T, Saito T, Okazawa H, Nagata T, Takeda S. In-frame dystrophin following exon 51-skipping improves muscle pathology and function in the exon 52-deficient mdx mouse. Mol Ther 2010; 18:1995-2005. [PMID: 20823833 DOI: 10.1038/mt.2010.186] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
A promising therapeutic approach for Duchenne muscular dystrophy (DMD) is exon skipping using antisense oligonucleotides (AOs). In-frame deletions of the hinge 3 region of the dystrophin protein, which is encoded by exons 50 and 51, are predicted to cause a variety of phenotypes. Here, we performed functional analyses of muscle in the exon 52-deleted mdx (mdx52) mouse, to predict the function of in-frame dystrophin following exon 51-skipping, which leads to a protein lacking most of hinge 3. A series of AOs based on phosphorodiamidate morpholino oligomers was screened by intramuscular injection into mdx52 mice. The highest splicing efficiency was generated by a two-oligonucleotide cocktail targeting both the 5' and 3' splice sites of exon 51. After a dose-escalation study, we systemically delivered this cocktail into mdx52 mice seven times at weekly intervals. This induced 20-30% of wild-type (WT) dystrophin expression levels in all muscles, and was accompanied by amelioration of the dystrophic pathology and improvement of skeletal muscle function. Because the structure of the restored in-frame dystrophin resembles human dystrophin following exon 51-skipping, our results are encouraging for the ongoing clinical trials for DMD. Moreover, the therapeutic dose required can provide a suggestion of the theoretical equivalent dose for humans.
Collapse
Affiliation(s)
- Yoshitsugu Aoki
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
420
|
Finkel RS. Read-through strategies for suppression of nonsense mutations in Duchenne/ Becker muscular dystrophy: aminoglycosides and ataluren (PTC124). J Child Neurol 2010; 25:1158-64. [PMID: 20519671 PMCID: PMC3674569 DOI: 10.1177/0883073810371129] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Nucleotide changes within an exon can alter the trinucleotide normally encoding a particular amino acid, such that a new ''stop'' signal is transcribed into the mRNA open reading frame. This causes the ribosome to prematurely terminate its reading of the mRNA, leading to nonsense-mediated decay of the transcript and lack of production of a normal full-length protein. Such premature termination codon mutations occur in an estimated 10% to 15% of many genetically based disorders, including Duchenne/Becker muscular dystrophy. Therapeutic strategies have been developed to induce ribosomal read-through of nonsense mutations in mRNA and allow production of a full-length functional protein. Small-molecule drugs (aminoglycosides and ataluren [PTC124]) have been developed and are in clinical testing in patients with nonsense mutations within the dystrophin gene. Use of nonsense mutation suppression in Duchenne/Becker muscular dystrophy may offer the prospect of targeting the specific mutation causing the disease and correcting the fundamental pathophysiology.
Collapse
Affiliation(s)
- Richard S. Finkel
- Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| |
Collapse
|
421
|
Tee JM, Peppelenbosch MP. Anchoring skeletal muscle development and disease: the role of ankyrin repeat domain containing proteins in muscle physiology. Crit Rev Biochem Mol Biol 2010; 45:318-30. [PMID: 20515317 PMCID: PMC2942773 DOI: 10.3109/10409238.2010.488217] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The ankyrin repeat is a protein module with high affinity for other ankyrin repeats based on strong Van der Waals forces. The resulting dimerization is unusually resistant to both mechanical forces and alkanization, making this module exceedingly useful for meeting the extraordinary demands of muscle physiology. Many aspects of muscle function are controlled by the superfamily ankyrin repeat domain containing proteins, including structural fixation of the contractile apparatus to the muscle membrane by ankyrins, the archetypical member of the family. Additionally, other ankyrin repeat domain containing proteins critically control the various differentiation steps during muscle development, with Notch and developmental stage-specific expression of the members of the Ankyrin repeat and SOCS box (ASB) containing family of proteins controlling compartment size and guiding the various steps of muscle specification. Also, adaptive responses in fully formed muscle require ankyrin repeat containing proteins, with Myotrophin/V-1 ankyrin repeat containing proteins controlling the induction of hypertrophic responses following excessive mechanical load, and muscle ankyrin repeat proteins (MARPs) acting as protective mechanisms of last resort following extreme demands on muscle tissue. Knowledge on mechanisms governing the ordered expression of the various members of superfamily of ankyrin repeat domain containing proteins may prove exceedingly useful for developing novel rational therapy for cardiac disease and muscle dystrophies.
Collapse
Affiliation(s)
- Jin-Ming Tee
- Hubrecht Institute for Developmental Biology and Stem Cell Research-University Medical Center Utrecht, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | | |
Collapse
|
422
|
Reliable resequencing of the human dystrophin locus by universal long polymerase chain reaction and massive pyrosequencing. Anal Biochem 2010; 406:176-84. [PMID: 20670611 DOI: 10.1016/j.ab.2010.07.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 07/19/2010] [Accepted: 07/20/2010] [Indexed: 01/07/2023]
Abstract
The X-linked dystrophin gene is well known for its involvement in Duchenne/Becker muscular dystrophies and for its exceptional megabase size. This locus at Xp21 is prone to frequent random molecular changes, including large deletions and duplications, but also smaller variations. To cope with such huge sequence analysis requirements in forthcoming diagnostic applications, we employed the power of the parallel 454 GS-FLX pyrosequencer to the dystrophin locus. We enriched the genomic region of interest by the robust amplification of 62 fragments under universal conditions by the long-PCR protocol yielding 244,707 bp of sequence. Pooled PCR products were fragmented and used for library preparation and DNA sequencing. To evaluate the entire procedure we analyzed four male DNA samples for sequence coverage and accuracy in DNA sequence variation and for any potential bias. We identified 562 known variations and 55 additional variants not yet reported, among which we detected a causative Arg1844Stop mutation in one sample. Sanger sequencing confirmed all changes. Unexpectedly, only 3 x coverage was sufficient for 99.9993% accuracy. Our results show that long PCR combined to massive pyrosequencing is very reliable for the analysis of the biggest gene of the human genome and open the doors to other demanding applications in molecular diagnostics.
Collapse
|
423
|
Kondo-Iida E. Commentary on 'Mutation spectrum of the dystrophin gene in 442 Duchenne/Becker muscular dystrophy cases from one Japanese referral center'. J Hum Genet 2010; 55:555-6. [PMID: 20555341 DOI: 10.1038/jhg.2010.69] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Eri Kondo-Iida
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| |
Collapse
|
424
|
Takeshima Y, Yagi M, Okizuka Y, Awano H, Zhang Z, Yamauchi Y, Nishio H, Matsuo M. Mutation spectrum of the dystrophin gene in 442 Duchenne/Becker muscular dystrophy cases from one Japanese referral center. J Hum Genet 2010; 55:379-88. [PMID: 20485447 DOI: 10.1038/jhg.2010.49] [Citation(s) in RCA: 169] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Recent developments in molecular therapies for Duchenne muscular dystrophy (DMD) demand accurate genetic diagnosis, because therapies are mutation specific. The KUCG (Kobe University Clinical Genetics) database for DMD and Becker muscular dystrophy is a hospital-based database comprising 442 cases. Using a combination of complementary DNA (cDNA) and chromosome analysis in addition to conventional genomic DNA-based method, mutation detection was successfully accomplished in all cases, and the largest mutation database of Japanese dystrophinopathy was established. Among 442 cases, deletions and duplications encompassing one or more exons were identified in 270 (61%) and 38 (9%) cases, respectively. Nucleotide changes leading to nonsense mutations or disrupting a splice site were identified in 69 (16%) or 24 (5%) cases, respectively. Small deletion/insertion mutations were identified in 34 (8%) cases. Remarkably, two retrotransposon insertion events were also identified. Dystrophin cDNA analysis successfully revealed novel transcripts with a pseudoexon created by a single-nucleotide change deep within an intron in four cases. X-chromosome abnormalities were identified in two cases. The reading frame rule was upheld for 93% of deletion and 66% of duplication mutation cases. For the application of molecular therapies, induction of exon skipping was deemed the first priority for dystrophinopathy treatment. At one Japanese referral center, the hospital-based mutation database of the dystrophin gene was for the first time established with the highest levels of quality and patient's number.
Collapse
Affiliation(s)
- Yasuhiro Takeshima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
425
|
Miyagoe-Suzuki Y, Takeda S. Gene therapy for muscle disease. Exp Cell Res 2010; 316:3087-92. [PMID: 20580709 DOI: 10.1016/j.yexcr.2010.05.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 05/13/2010] [Accepted: 05/17/2010] [Indexed: 12/31/2022]
Abstract
The molecular mechanisms of Duchenne muscular dystrophy (DMD) have been extensively investigated since the discovery of the dystrophin gene in 1986. Nonetheless, there is currently no effective treatment for DMD. Recent reports, however, indicate that adenoassociated viral (AAV) vector-mediated transfer of a functional dystrophin cDNA into the affected muscle is a promising strategy. In addition, antisense-mediated exon skipping technology has been emerging as another promising approach to restore dystrophin expression in DMD muscle. Ongoing clinical trials show restoration of dystrophin in DMD patients without serious side effects. Here, we summarize the recent progress in gene therapy, with an emphasis on exon skipping for DMD.
Collapse
Affiliation(s)
- Yuko Miyagoe-Suzuki
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo, Japan
| | | |
Collapse
|
426
|
Dystrophin: more than just the sum of its parts. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:1713-22. [PMID: 20472103 DOI: 10.1016/j.bbapap.2010.05.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 04/30/2010] [Accepted: 05/03/2010] [Indexed: 01/05/2023]
Abstract
Dystrophin is one of a number of large cytoskeleton associated proteins that connect between various cytoskeletal elements and often are tethered to the membrane through other transmembrane protein complexes. These cytolinker proteins often provide structure and support to the cells where they are expressed, and mutations in genes encoding these proteins frequently gives rise to disease. Dystrophin is no exception in any of these respects, providing connections between a transmembrane complex known as the dystrophin-glycoprotein complex and the underlying cytoskeleton. The most established connection and possibly the most important is that to F-actin, but more recently evidence has been forthcoming of connections to membrane phospholipids, intermediate filaments and microtubules. Moreover it is becoming increasingly clear that the multiple spectrin-like repeats in the centre of the molecule, that had hitherto been thought to be largely redundant, harbour binding activities that have a significant impact on dystrophin functionality. This functionality is particularly apparent when assessed by the ability to rescue the dystrophic phenotype in mdx mice. This review will focus on the relatively neglected but functionally vital coiled-coil region of dystrophin, highlighting the structural relationships and interactions of the coiled-coil region and providing new insights into the functional role of this region.
Collapse
|
427
|
Heemskerk H, de Winter C, van Kuik P, Heuvelmans N, Sabatelli P, Rimessi P, Braghetta P, van Ommen GJB, de Kimpe S, Ferlini A, Aartsma-Rus A, van Deutekom JCT. Preclinical PK and PD studies on 2'-O-methyl-phosphorothioate RNA antisense oligonucleotides in the mdx mouse model. Mol Ther 2010; 18:1210-7. [PMID: 20407428 PMCID: PMC2889733 DOI: 10.1038/mt.2010.72] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Antisense oligonucleotides (AONs) are being developed as RNA therapeutic molecules for Duchenne muscular dystrophy. For oligonucleotides with the 2′-O-methyl-phosphorothioate (2OMePS) RNA chemistry, proof of concept has been obtained in patient-specific muscle cell cultures, the mouse and dog disease models, and recently by local administration in Duchenne patients. To further explore the pharmacokinetic (PK)/pharmacodynamic (PD) properties of this chemical class of oligonucleotides, we performed a series of preclinical studies in mice. The results demonstrate that the levels of oligonucleotides in dystrophin-deficient muscle fibers are much higher than in healthy fibers, leading to higher exon-skipping levels. Oligonucleotide levels and half-life differed for specific muscle groups, with heart muscle showing the lowest levels but longest half-life (~46 days). Intravenous (i.v.), subcutaneous (s.c.), and intraperitoneal (i.p.) delivery methods were directly compared. For each method, exon-skipping and novel dystrophin expression were observed in all muscles, including arrector pili smooth muscle in skin biopsies. After i.v. administration, the oligonucleotide peak levels in plasma, liver, and kidney were higher than after s.c. or i.p. injections. However, as the bioavailability was similar, and the levels of oligonucleotide, exon-skipping, and dystrophin steadily accumulated overtime after s.c. administration, we selected this patient-convenient delivery method for future clinical study protocols.
Collapse
Affiliation(s)
- Hans Heemskerk
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
428
|
Muntoni F. The development of antisense oligonucleotide therapies for Duchenne muscular dystrophy: report on a TREAT-NMD workshop hosted by the European Medicines Agency (EMA), on September 25th 2009. Neuromuscul Disord 2010; 20:355-62. [PMID: 20347306 DOI: 10.1016/j.nmd.2010.03.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Indexed: 10/19/2022]
Affiliation(s)
- F Muntoni
- The Dubowitz Neuromuscular Centre, University College London, Institute of Child Health, 30 Guildford Street, London WC1N1EH, UK.
| | | |
Collapse
|
429
|
Dystrophin isoform induction in vivo by antisense-mediated alternative splicing. Mol Ther 2010; 18:1218-23. [PMID: 20332768 DOI: 10.1038/mt.2010.45] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Antisense oligomer-induced manipulation of dystrophin pre-mRNA processing can remove exons carrying mutations, or exclude exons flanking frameshifting mutations, and restore dystrophin expression in dystrophinopathy models and in Duchenne muscular dystrophy (DMD) patients. Splice intervention can also be used to manipulate the normal dystrophin pre-mRNA processing and ablate dystrophin expression in wild-type mice, with signs of pathology being induced in selected muscles within 4 weeks of commencing treatment. The disruption of normal dystrophin pre-mRNA processing to alter the reading frame can be very efficient and offers an alternative mechanism to RNA silencing for gene suppression. In addition, it is possible to remove in-frame exon blocks from the DMD gene transcript and induce specific dystrophin isoforms that retain partial functionality, without having to generate transgenic animal models. Specific exon removal to yield in-frame dystrophin transcripts will facilitate mapping of functional protein domains, based upon exon boundaries, and will be particularly relevant where there is either limited, or conflicting information as to the consequences of in-frame dystrophin exon deletions on the clinical severity and progression of the dystrophinopathy.
Collapse
|
430
|
Yang ML, Finkel RS. Overview of paediatric neuromuscular disorders and related pulmonary issues: diagnostic and therapeutic considerations. Paediatr Respir Rev 2010; 11:9-17. [PMID: 20113986 DOI: 10.1016/j.prrv.2009.10.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Pulmonary compromise is common in neuromuscular disease. Respiratory failure may be a presenting feature of neuromuscular disease and remains a major cause of morbidity and mortality. This article will review the current understanding of the more commonly encountered neuromuscular disorders in childhood and emphasize related pulmonary issues.
Collapse
Affiliation(s)
- M L Yang
- Children's Hospital Denver, Aurora, CO 80045-7106, USA
| | | |
Collapse
|
431
|
Spitali P, Rimessi P, Fabris M, Perrone D, Falzarano S, Bovolenta M, Trabanelli C, Mari L, Bassi E, Tuffery S, Gualandi F, Maraldi NM, Sabatelli-Giraud P, Medici A, Merlini L, Ferlini A. Exon skipping-mediated dystrophin reading frame restoration for small mutations. Hum Mutat 2010; 30:1527-34. [PMID: 19760747 DOI: 10.1002/humu.21092] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Exon skipping using antisense oligonucleotides (AONs) has successfully been used to reframe the mRNA in various Duchenne muscular dystrophy patients carrying deletions in the DMD gene. In this study we tested the feasibility of the exon skipping approach for patients with small mutations in in-frame exons. We first identified 54 disease-causing point mutations. We selected five patients with nonsense or frameshifting mutations in exons 10, 16, 26, 33, and 34. Wild-type and mutation specific 2'OMePS AONs were tested in cell-free splicing assays and in cultured cells derived from the selected patients. The obtained results confirm cell-free splicing assay as an alternative system to test exon skipping propensity when patients' cells are unavailable. In myogenic cells, similar levels of exon skipping were observed for wild-type and mutation specific AONs for exons 16, 26, and 33, whereas for exon 10 and exon 34 the efficacy of the AONs was significantly different. Interestingly, in some cases skipping efficiencies for mutated exons were quite dissimilar when compared with previous reports on the respective wild-type exons. This behavior may be related to the effect of the mutations on exon skipping propensity, and highlights the complexity of identifying optimal AONs for skipping exons with small mutations.
Collapse
Affiliation(s)
- Pietro Spitali
- Department of Experimental and Diagnostic Medicine, Section of Medical Genetics, University of Ferrara, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
432
|
Wood MJA, Gait MJ, Yin H. RNA-targeted splice-correction therapy for neuromuscular disease. Brain 2010; 133:957-72. [PMID: 20150322 DOI: 10.1093/brain/awq002] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Splice-modulation therapy, whereby molecular manipulation of premessenger RNA splicing is engineered to yield genetic correction, is a promising novel therapy for genetic diseases of muscle and nerve-the prototypical example being Duchenne muscular dystrophy. Duchenne muscular dystrophy is the most common childhood genetic disease, affecting one in 3500 newborn boys, causing progressive muscle weakness, heart and respiratory failure and premature death. No cure exists for this disease and a number of promising new molecular therapies are being intensively studied. Duchenne muscular dystrophy arises due to mutations that disrupt the open-reading-frame in the DMD gene leading to the absence of the essential muscle protein dystrophin. Of all novel molecular interventions currently being investigated for Duchenne muscular dystrophy, perhaps the most promising method aiming to restore dystrophin expression to diseased cells is known as 'exon skipping' or splice-modulation, whereby antisense oligonucleotides eliminate the deleterious effects of DMD mutations by modulating dystrophin pre-messenger RNA splicing, such that functional dystrophin protein is produced. Recently this method was shown to be promising and safe in clinical trials both in The Netherlands and the UK. These trials studied direct antisense oligonucleotide injections into single peripheral lower limb muscles, whereas a viable therapy will need antisense oligonucleotides to be delivered systemically to all muscles, most critically to the heart, and ultimately to all other affected tissues including brain. There has also been considerable progress in understanding how such splice-correction methods could be applied to the treatment of related neuromuscular diseases, including spinal muscular atrophy and myotonic dystrophy, where defects of splicing or alternative splicing are closely related to the disease mechanism.
Collapse
Affiliation(s)
- Matthew J A Wood
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK.
| | | | | |
Collapse
|
433
|
Flanigan KM, Dunn DM, von Niederhausern A, Soltanzadeh P, Gappmaier E, Howard MT, Sampson JB, Mendell JR, Wall C, King WM, Pestronk A, Florence JM, Connolly AM, Mathews KD, Stephan CM, Laubenthal KS, Wong BL, Morehart PJ, Meyer A, Finkel RS, Bonnemann CG, Medne L, Day JW, Dalton JC, Margolis MK, Hinton VJ, Weiss RB. Mutational spectrum of DMD mutations in dystrophinopathy patients: application of modern diagnostic techniques to a large cohort. Hum Mutat 2010; 30:1657-66. [PMID: 19937601 DOI: 10.1002/humu.21114] [Citation(s) in RCA: 236] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mutations in the DMD gene, encoding the dystrophin protein, are responsible for the dystrophinopathies Duchenne Muscular Dystrophy (DMD), Becker Muscular Dystrophy (BMD), and X-linked Dilated Cardiomyopathy (XLDC). Mutation analysis has traditionally been challenging, due to the large gene size (79 exons over 2.2 Mb of genomic DNA). We report a very large aggregate data set comprised of DMD mutations detected in samples from patients enrolled in the United Dystrophinopathy Project, a multicenter research consortium, and in referral samples submitted for mutation analysis with a diagnosis of dystrophinopathy. We report 1,111 mutations in the DMD gene, including 891 mutations with associated phenotypes. These results encompass 506 point mutations (including 294 nonsense mutations) and significantly expand the number of mutations associated with the dystrophinopathies, highlighting the utility of modern diagnostic techniques. Our data supports the uniform hypermutability of CGA>TGA mutations, establishes the frequency of polymorphic muscle (Dp427m) protein isoforms and reveals unique genomic haplotypes associated with "private" mutations. We note that 60% of these patients would be predicted to benefit from skipping of a single DMD exon using antisense oligonucleotide therapy, and 62% would be predicted to benefit from an inclusive multiexonskipping approach directed toward exons 45 through 55.
Collapse
Affiliation(s)
- Kevin M Flanigan
- Departments of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
434
|
Taylor PJ, Betts GA, Maroulis S, Gilissen C, Pedersen RL, Mowat DR, Johnston HM, Buckley MF. Dystrophin gene mutation location and the risk of cognitive impairment in Duchenne muscular dystrophy. PLoS One 2010; 5:e8803. [PMID: 20098710 PMCID: PMC2808359 DOI: 10.1371/journal.pone.0008803] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Accepted: 12/31/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND A significant component of the variation in cognitive disability that is observed in Duchenne muscular dystrophy (DMD) is known to be under genetic regulation. In this study we report correlations between standardised measures of intelligence and mutational class, mutation size, mutation location and the involvement of dystrophin isoforms. METHODS AND RESULTS Sixty two male subjects were recruited as part of a study of the cognitive spectrum in boys with DMD conducted at the Sydney Children's Hospital (SCH). All 62 children received neuropsychological testing from a single clinical psychologist and had a defined dystrophin gene (DMD) mutation; including DMD gene deletions, duplications and DNA point mutations. Full Scale Intelligence Quotients (FSIQ) in unrelated subjects with the same mutation were found to be highly correlated (r = 0.83, p = 0.0008), in contrast to results in previous publications. In 58 cases (94%) it was possible to definitively assign a mutation as affecting one or more dystrophin isoforms. A strong association between the risk of cognitive disability and the involvement of groups of DMD isoforms was found. In particular, improvements in the correlation of FSIQ with mutation location were identified when a new classification system for mutations affecting the Dp140 isoform was implemented. SIGNIFICANCE These data represent one of the largest studies of FSIQ and mutational data in DMD patients and is among the first to report on a DMD cohort which has had both comprehensive mutational analysis and FSIQ testing through a single referral centre. The correlation between FSIQ results with the location of the dystrophin gene mutation suggests that the risk of cognitive deficit is a result of the cumulative loss of central nervous system (CNS) expressed dystrophin isoforms, and that correct classification of isoform involvement results in improved estimates of risk.
Collapse
Affiliation(s)
- Peter J. Taylor
- Molecular and Cytogenetics Unit, Department of Haematology and Genetics, Prince of Wales Hospital, Randwick, Sydney, New South Wales, Australia
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - Grant A. Betts
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - Sarah Maroulis
- Molecular and Cytogenetics Unit, Department of Haematology and Genetics, Prince of Wales Hospital, Randwick, Sydney, New South Wales, Australia
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Robyn L. Pedersen
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - David R. Mowat
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
- The School of Women's and Children's Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Heather M. Johnston
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - Michael F. Buckley
- Molecular and Cytogenetics Unit, Department of Haematology and Genetics, Prince of Wales Hospital, Randwick, Sydney, New South Wales, Australia
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| |
Collapse
|
435
|
Walmsley GL, Arechavala-Gomeza V, Fernandez-Fuente M, Burke MM, Nagel N, Holder A, Stanley R, Chandler K, Marks SL, Muntoni F, Shelton GD, Piercy RJ. A duchenne muscular dystrophy gene hot spot mutation in dystrophin-deficient cavalier king charles spaniels is amenable to exon 51 skipping. PLoS One 2010; 5:e8647. [PMID: 20072625 PMCID: PMC2800183 DOI: 10.1371/journal.pone.0008647] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 12/10/2009] [Indexed: 11/26/2022] Open
Abstract
Background Duchenne muscular dystrophy (DMD), which afflicts 1 in 3500 boys, is one of the most common genetic disorders of children. This fatal degenerative condition is caused by an absence or deficiency of dystrophin in striated muscle. Most affected patients have inherited or spontaneous deletions in the dystrophin gene that disrupt the reading frame resulting in unstable truncated products. For these patients, restoration of the reading frame via antisense oligonucleotide-mediated exon skipping is a promising therapeutic approach. The major DMD deletion “hot spot” is found between exons 45 and 53, and skipping exon 51 in particular is predicted to ameliorate the dystrophic phenotype in the greatest number of patients. Currently the mdx mouse is the most widely used animal model of DMD, although its mild phenotype limits its suitability in clinical trials. The Golden Retriever muscular dystrophy (GRMD) model has a severe phenotype, but due to its large size, is expensive to use. Both these models have mutations in regions of the dystrophin gene distant from the commonly mutated DMD “hot spot”. Methodology/Principal Findings Here we describe the severe phenotype, histopathological findings, and molecular analysis of Cavalier King Charles Spaniels with dystrophin-deficient muscular dystrophy (CKCS-MD). The dogs harbour a missense mutation in the 5′ donor splice site of exon 50 that results in deletion of exon 50 in mRNA transcripts and a predicted premature truncation of the translated protein. Antisense oligonucleotide-mediated skipping of exon 51 in cultured myoblasts from an affected dog restored the reading frame and protein expression. Conclusions/Significance Given the small size of the breed, the amiable temperament and the nature of the mutation, we propose that CKCS-MD is a valuable new model for clinical trials of antisense oligonucleotide-induced exon skipping and other therapeutic approaches for DMD.
Collapse
Affiliation(s)
- Gemma L. Walmsley
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
| | | | - Marta Fernandez-Fuente
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, United Kingdom
| | - Margaret M. Burke
- Pathology Laboratory, Harefield Hospital, Royal Brompton & Harefield NHS Foundation Trust, Harefield, Middlesex, United Kingdom
| | - Nicole Nagel
- Alphapet Veterinary Clinic, Bognor Regis, West Sussex, United Kingdom
| | - Angela Holder
- Pathology and Infectious Diseases, Royal Veterinary College, London, United Kingdom
| | - Rachael Stanley
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
| | - Kate Chandler
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
| | - Stanley L. Marks
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, United Kingdom
| | - G. Diane Shelton
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Richard J. Piercy
- Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom
- Dubowitz Neuromuscular Centre, Institute of Child Health, University College London, United Kingdom
- * E-mail:
| |
Collapse
|
436
|
Yamashita K, Suzuki A, Satoh Y, Ide M, Amano Y, Masuda-Hirata M, Hayashi YK, Hamada K, Ogata K, Ohno S. The 8th and 9th tandem spectrin-like repeats of utrophin cooperatively form a functional unit to interact with polarity-regulating kinase PAR-1b. Biochem Biophys Res Commun 2010; 391:812-7. [DOI: 10.1016/j.bbrc.2009.11.144] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 11/24/2009] [Indexed: 10/20/2022]
|
437
|
Torella A, Trimarco A, Del Vecchio Blanco F, Cuomo A, Aurino S, Piluso G, Minetti C, Politano L, Nigro V. One hundred twenty-one dystrophin point mutations detected from stored DNA samples by combinatorial denaturing high-performance liquid chromatography. J Mol Diagn 2010; 12:65-73. [PMID: 19959795 PMCID: PMC2797720 DOI: 10.2353/jmoldx.2010.090074] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2009] [Indexed: 11/20/2022] Open
Abstract
Duchenne and Becker muscular dystrophies are caused by a large number of different mutations in the dystrophin gene. Outside of the deletion/duplication "hot spots," small mutations occur at unpredictable positions. These account for about 15 to 20% of cases, with the major group being premature stop codons. When the affected male is deceased, carrier testing for family members and prenatal diagnosis become difficult and expensive. We tailored a cost-effective and reliable strategy to discover point mutations from stored DNA samples in the absence of a muscle biopsy. Samples were amplified in combinatorial pools and tested by denaturing high-performance liquid chromatography analysis. An anomalous elution profile belonging to two different pools univocally addressed the allelic variation to an unambiguous sample. Mutations were then detected by sequencing. We identified 121 mutations of 99 different types. Fifty-six patients show stop codons that represent the 46.3% of all cases. Three non-obvious single amino acid mutations were considered as causative. Our data support combinatorial denaturing high-performance liquid chromatography analysis as a clear-cut strategy for time and cost-effective identification of small mutations when only DNA is available.
Collapse
Affiliation(s)
- Annalaura Torella
- Dipartimento di Patologia Generale, Seconda Università degli Studi di Napoli, Naples, Italy
| | - Amelia Trimarco
- Dipartimento di Patologia Generale, Seconda Università degli Studi di Napoli, Naples, Italy
| | | | - Anna Cuomo
- Dipartimento di Patologia Generale, Seconda Università degli Studi di Napoli, Naples, Italy
| | - Stefania Aurino
- Dipartimento di Patologia Generale, Seconda Università degli Studi di Napoli, Naples, Italy
- Telethon Institute of Genetics and Medicine, Naples, Italy
| | - Giulio Piluso
- Dipartimento di Patologia Generale, Seconda Università degli Studi di Napoli, Naples, Italy
| | - Carlo Minetti
- Università degli Studi di Genova, Istituto Giannina Gaslini, Genua, Italy
| | - Luisa Politano
- Dipartimento di Medicina Sperimentale, Seconda Università degli Studi di Napoli, Naples, Italy
| | - Vincenzo Nigro
- Dipartimento di Patologia Generale, Seconda Università degli Studi di Napoli, Naples, Italy
- Telethon Institute of Genetics and Medicine, Naples, Italy
| |
Collapse
|
438
|
O'Leary DA, Sharif O, Anderson P, Tu B, Welch G, Zhou Y, Caldwell JS, Engels IH, Brinker A. Identification of small molecule and genetic modulators of AON-induced dystrophin exon skipping by high-throughput screening. PLoS One 2009; 4:e8348. [PMID: 20020055 PMCID: PMC2791862 DOI: 10.1371/journal.pone.0008348] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 11/23/2009] [Indexed: 11/28/2022] Open
Abstract
One therapeutic approach to Duchenne Muscular Dystrophy (DMD) recently entering clinical trials aims to convert DMD phenotypes to that of a milder disease variant, Becker Muscular Dystrophy (BMD), by employing antisense oligonucleotides (AONs) targeting splice sites, to induce exon skipping and restore partial dystrophin function. In order to search for small molecule and genetic modulators of AON-dependent and independent exon skipping, we screened ∼10,000 known small molecule drugs, >17,000 cDNA clones, and >2,000 kinase- targeted siRNAs against a 5.6 kb luciferase minigene construct, encompassing exon 71 to exon 73 of human dystrophin. As a result, we identified several enhancers of exon skipping, acting on both the reporter construct as well as endogenous dystrophin in mdx cells. Multiple mechanisms of action were identified, including histone deacetylase inhibition, tubulin modulation and pre-mRNA processing. Among others, the nucleolar protein NOL8 and staufen RNA binding protein homolog 2 (Stau2) were found to induce endogenous exon skipping in mdx cells in an AON-dependent fashion. An unexpected but recurrent theme observed in our screening efforts was the apparent link between the inhibition of cell cycle progression and the induction of exon skipping.
Collapse
Affiliation(s)
- Debra A. O'Leary
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
- * E-mail: (DAO); (IHE)
| | - Orzala Sharif
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Paul Anderson
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Buu Tu
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Genevieve Welch
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Yingyao Zhou
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Jeremy S. Caldwell
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Ingo H. Engels
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
- * E-mail: (DAO); (IHE)
| | - Achim Brinker
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| |
Collapse
|
439
|
Abstract
PURPOSE OF REVIEW Duchenne muscular dystrophy is a progressive muscle degenerative disease caused by dystrophin mutations. The purpose of this review is to highlight two emerging therapies designed to repair the primary genetic defect, called 'exon skipping' and 'nonsense codon suppression'. RECENT FINDINGS A drug, PTC124, was identified that suppresses nonsense codon translation termination. PTC124 can lead to restoration of some dystrophin expression in human Duchenne muscular dystrophy muscles with mutations resulting in premature stops. Two drugs developed for exon skipping, PRO051 and AVI-4658, result in the exclusion of exon 51 from mature mRNA. They can restore the translational reading frame to dystrophin transcripts from patients with a particular subset of dystrophin gene deletions and lead to some restoration of dystrophin expression in affected boys' muscle in vivo. Both approaches have concluded phase I trials with no serious adverse events. SUMMARY These novel therapies that act to correct the primary genetic defect of dystrophin deficiency are among the first generation of therapies tailored to correct specific mutations in humans. Thus, they represent paradigm forming approaches to personalized medicine with the potential to lead to life changing treatment for those affected by Duchenne muscular dystrophy.
Collapse
|
440
|
Venance SL, Koopman WJ. DYSTROPHINOPATHIES IN ADULTHOOD. Continuum (Minneap Minn) 2009. [DOI: 10.1212/01.con.0000348875.86198.fa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
441
|
Girardet A, Fernandez C, Claustres M. Rapid and powerful decaplex and dodecaplex PGD protocols for Duchenne muscular dystrophy. Reprod Biomed Online 2009; 19:830-7. [DOI: 10.1016/j.rbmo.2009.09.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
442
|
Ferlini A, Sabatelli P, Fabris M, Bassi E, Falzarano S, Vattemi G, Perrone D, Gualandi F, Maraldi NM, Merlini L, Sparnacci K, Laus M, Caputo A, Bonaldo P, Braghetta P, Rimessi P. Dystrophin restoration in skeletal, heart and skin arrector pili smooth muscle of mdx mice by ZM2 NP-AON complexes. Gene Ther 2009; 17:432-8. [PMID: 19907501 DOI: 10.1038/gt.2009.145] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Potentially viable therapeutic approaches for Duchenne muscular dystrophy (DMD) are now within reach. Indeed, clinical trials are currently under way. Two crucial aspects still need to be addressed: maximizing therapeutic efficacy and identifying appropriate and sensible outcome measures. Nevertheless, the end point of these trials remains painful muscle biopsy to show and quantify protein restoration in treated boys. In this study we show that PMMA/N-isopropil-acrylamide+ (NIPAM) nanoparticles (ZM2) bind and convey antisense oligoribonucleotides (AONs) very efficiently. Systemic injection of the ZM2-AON complex restored dystrophin protein synthesis in both skeletal and cardiac muscles of mdx mice, allowing protein localization in up to 40% of muscle fibers. The mdx exon 23 skipping level was up to 20%, as measured by the RealTime assay, and dystrophin restoration was confirmed by both reverse transcription-PCR and western blotting. Furthermore, we verified that dystrophin restoration also occurs in the smooth muscle cells of the dorsal skin arrector pili, an easily accessible histological structure, in ZM2-AON-treated mdx mice, with respect to untreated animals. This finding reveals arrector pili smooth muscle to be an appealing biomarker candidate and a novel low-invasive treatment end point. Furthermore, this marker would also be suitable for subsequent monitoring of the therapeutic effects in DMD patients. In addition, we demonstrate herein the expression of other sarcolemma proteins such as alpha-, beta-, gamma- and delta-sarcoglycans in the human skin arrector pili smooth muscle, thereby showing the potential of this muscle as a biomarker for other muscular dystrophies currently or soon to be the object of clinical trials.
Collapse
Affiliation(s)
- A Ferlini
- Department of Experimental and Diagnostic Medicine, Section of Medical Genetics, University of Ferrara, Ferrara, Italy.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
443
|
Le Roy F, Charton K, Lorson CL, Richard I. RNA-targeting approaches for neuromuscular diseases. Trends Mol Med 2009; 15:580-91. [PMID: 19906562 DOI: 10.1016/j.molmed.2009.10.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 09/25/2009] [Accepted: 10/08/2009] [Indexed: 12/16/2022]
Abstract
Although most molecular therapy strategies for genetic diseases are based on gene replacement, interesting alternative approaches target RNA. These strategies rely on the modification of the mutated gene's expression in vivo by modulating pre-mRNA splicing, mRNA stability or mRNA translation. Here, we review recent progress using these RNA-based approaches in the field of muscle and muscle-related genetic diseases. Different molecular tools, including modified antisense oligonucleotides, pre-mRNA trans-splicing molecules, ribozymes or chemical compounds have been used successfully on patient cells or animal models of disease. These diverse strategies show tremendous therapeutic potential and several clinical trials have been initiated with Duchenne muscular dystrophy patients with promising results.
Collapse
Affiliation(s)
- Florence Le Roy
- Généthon, CNRS/UEVE UMR8587 LAMBE, 1, rue de l'Internationale, 91000 Evry, France
| | | | | | | |
Collapse
|
444
|
Aartsma-Rus A, van Ommen GJB. Progress in therapeutic antisense applications for neuromuscular disorders. Eur J Hum Genet 2009; 18:146-53. [PMID: 19809477 DOI: 10.1038/ejhg.2009.160] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Neuromuscular disorders are a frequent cause of chronic disability in man. They often result from mutations in single genes and are thus, in principle, well suited for gene therapy. However, the tissues involved (muscle and the central nervous system) are post-mitotic, which poses a challenge for most viral vectors. In some cases, alternative approaches may use small molecules, for example, antisense oligonucleotides (AONs). These do not deliver a new gene, but rather modulate existing gene products or alter the utilization of pathways. For Duchenne muscular dystrophy, this approach is in early phase clinical trials, and for two other common neuromuscular disorders (spinal muscular atrophy and myotonic dystrophy), significant preclinical advances have recently been made.
Collapse
Affiliation(s)
- Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
| | | |
Collapse
|
445
|
Basak J, Dasgupta UB, Mukherjee SC, Das SK, Senapati AK, Banerjee TK. Deletional mutations of dystrophin gene and carrier detection in eastern India. Indian J Pediatr 2009; 76:1007-12. [PMID: 19907931 DOI: 10.1007/s12098-009-0214-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Accepted: 12/29/2008] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine the pattern of deletions of the dystrophin gene, the major class of mutations among the Duchenne and Becker muscular dystrophy patients of eastern India and to analyze the carrier frequency of the female members of the proband's family. METHODS Deletional mutations occurring in patients have been characterized by multiplex polymerase chain reaction. Carrier state of mothers and sisters of probands were analyzed by either of two methods: 1) typing polymorphic short tandem repeat markers in or around the regions of deletion, by radioactive polymerase chain reaction and 2) quantitative real time amplification of the region of deletion. RESULTS Deletions were detected in 67 (62.04%) out of 108 male patients, about 76.12% of these being localized in the central hot spot region of the gene, i.e., between exon 42 to exon 53 and 17.91% at the proximal hot spot i.e., between exon 1 to exon 20. In the present study were found 43 types of deletions, out of which 25 (58%) were new deletions, which were not described earlier among the Indian patients. Distribution pattern of deletions in different hot spot regions has been compared with that of other countries and statistical analysis reveals significant difference between countries (p<0.001). Correlation of the pattern of deletion with clinical phenotype of patients has been discussed. Interesting case of germline mosaicism and its implications in counseling has also been discussed. CONCLUSION About half the mothers of affected probands were not carriers of the deletion, underscoring the need to use real time techniques for carrier detection.
Collapse
Affiliation(s)
- Jayasri Basak
- Department of Biophysics, Molecular Biology and Genetics, University of Calcutta, Kolkata, India.
| | | | | | | | | | | |
Collapse
|
446
|
Tuffery-Giraud S, Béroud C, Leturcq F, Yaou RB, Hamroun D, Michel-Calemard L, Moizard MP, Bernard R, Cossée M, Boisseau P, Blayau M, Creveaux I, Guiochon-Mantel A, de Martinville B, Philippe C, Monnier N, Bieth E, Khau Van Kien P, Desmet FO, Humbertclaude V, Kaplan JC, Chelly J, Claustres M. Genotype-phenotype analysis in 2,405 patients with a dystrophinopathy using the UMD-DMD database: a model of nationwide knowledgebase. Hum Mutat 2009; 30:934-45. [PMID: 19367636 DOI: 10.1002/humu.20976] [Citation(s) in RCA: 257] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
UMD-DMD France is a knowledgebase developed through a multicenter academic effort to provide an up-to-date resource of curated information covering all identified mutations in patients with a dystrophinopathy. The current release includes 2,411 entries consisting in 2,084 independent mutational events identified in 2,046 male patients and 38 expressing females, which corresponds to an estimated number of 39 people per million with a genetic diagnosis of dystrophinopathy in France. Mutations consist in 1,404 large deletions, 215 large duplications, and 465 small rearrangements, of which 39.8% are nonsense mutations. The reading frame rule holds true for 96% of the DMD patients and 93% of the BMD patients. Quality control relies on the curation by four experts for the DMD gene and related diseases. Data on dystrophin and RNA analysis, phenotypic groups, and transmission are also available. About 24% of the mutations are de novo events. This national centralized resource will contribute to a greater understanding of prevalence of dystrophinopathies in France, and in particular, of the true frequency of BMD, which was found to be almost half (43%) that of DMD. UMD-DMD is a searchable anonymous database that includes numerous newly developed tools, which can benefit to all the scientific community interested in dystrophinopathies. Dedicated functions for genotype-based therapies allowed the prediction of a new multiexon skipping (del 45-53) potentially applicable to 53% of the deleted DMD patients. Finally, such a national database will prove to be useful to implement the international global DMD patients' registries under development.
Collapse
|
447
|
Wakefield SE, Dimberg EL, Moore SA, Tseng BS. Dystrophinopathy presenting with arrhythmia in an asymptomatic 34-year-old man: a case report. J Med Case Rep 2009; 3:8625. [PMID: 19830234 PMCID: PMC2737755 DOI: 10.4076/1752-1947-3-8625] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 02/13/2009] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION Important clues in the recognition of individuals with dystrophin gene mutations are illuminated in this case report. In particular, this report seeks to broaden the perspective of early signs and symptoms of a potentially life-limiting genetic disorder. This group of disorders is generally considered to be a pediatric muscular dystrophy when in actual fact, this case report may represent a spectrum of subclinically affected adults. CASE PRESENTATION We present the diagnostic saga of a 34-year-old Caucasian man who had two liver biopsies for elevated liver enzymes and 16 years later presented with a cardiac arrhythmia amidst an emergent appendectomy which finally led to his specific genetic diagnosis. CONCLUSIONS This genetic disorder can affect more than one organ, and in our patient affected both skeletal and cardiac muscle. Furthermore, liver function tests when elevated may erroneously implicate a liver disorder when they actually reflect cardiac and skeletal muscle origin. Presented here is a patient with Becker's muscular dystrophy and cardiomyopathy.
Collapse
Affiliation(s)
- Seth E Wakefield
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Elliot L Dimberg
- Department of Neurology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Steven A Moore
- Department of Pathology, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Brian S Tseng
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| |
Collapse
|
448
|
Wang Z, Chamberlain JS, Tapscott SJ, Storb R. Gene therapy in large animal models of muscular dystrophy. ILAR J 2009; 50:187-98. [PMID: 19293461 DOI: 10.1093/ilar.50.2.187] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The muscular dystrophies are a group of genetically and phenotypically heterogeneously inherited diseases characterized by progressive muscle wasting, which can lead to premature death in severe forms such as Duchenne muscular dystrophy (DMD). In many cases they are caused by the absence of proteins that are critical components of the dystrophin-glycoprotein complex, which links the cytoskeleton and the basal lamina. There is no effective treatment for these disorders at present, but several novel strategies for replacing or repairing the defective gene are in development, with early encouraging results from animal models. We review these strategies, which include the use of stem cells of different tissue origins, gene replacement therapies mediated by various viral vectors, and transcript repair treatments using exon skipping strategies. We comment on their advantages and on limitations that must be overcome before successful application to human patients. Our focus is on studies in a clinically relevant large canine model of DMD. Recent advances in the field suggest that effective therapies for muscular dystrophies are on the horizon. Because of the complex nature of these diseases, it may be necessary to combine multiple approaches to achieve a successful treatment.
Collapse
Affiliation(s)
- Zejing Wang
- Division of Clinical Research, Fred Hutchinson Cancer Research Center in Seattle, Washington 98109, USA
| | | | | | | |
Collapse
|
449
|
Aartsma-Rus A, Fokkema I, Verschuuren J, Ginjaar I, van Deutekom J, van Ommen GJ, den Dunnen JT. Theoretic applicability of antisense-mediated exon skipping for Duchenne muscular dystrophy mutations. Hum Mutat 2009; 30:293-9. [PMID: 19156838 DOI: 10.1002/humu.20918] [Citation(s) in RCA: 393] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Antisense-mediated exon skipping aiming for reading frame restoration is currently a promising therapeutic application for Duchenne muscular dystrophy (DMD). This approach is mutation specific, but as the majority of DMD patients have deletions that cluster in hotspot regions, the skipping of a small number of exons is applicable to relatively large numbers of patients. To assess the actual applicability of the exon skipping approach, we here determined for deletions, duplications and point mutations reported in the Leiden DMD mutation database, which exon(s) should be skipped to restore the open reading frame. In theory, single and double exon skipping would be applicable to 79% of deletions, 91% of small mutations, and 73% of duplications, amounting to 83% of all DMD mutations. Exon 51 skipping, which is being tested in clinical trials, would be applicable to the largest group (13%) of all DMD patients. Further research is needed to determine the functionality of different in-frame dystrophins and a number of hurdles has to be overcome before this approach can be applied clinically.
Collapse
Affiliation(s)
- Annemieke Aartsma-Rus
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
450
|
Rapid and cost effective detection of small mutations in the DMD gene by high resolution melting curve analysis. Neuromuscul Disord 2009; 19:383-90. [PMID: 19409785 DOI: 10.1016/j.nmd.2009.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 02/17/2009] [Accepted: 03/17/2009] [Indexed: 11/21/2022]
Abstract
Duchenne/Becker muscular dystrophy (DMD/BMD) is caused by large deletions or duplications in two-thirds of the cases. The remaining one-third DMD patients have small mutations in the DMD gene. Screening for such small mutations is a daunting and costly task. High resolution melting curve analysis (HR-MCA) followed by sequencing for amplicons with altered melting profiles can be used to scan DNA for small alterations. We first validated the technique as screening procedure for the DMD gene and then screened a group of unrelated 22 DMD/BMD patients and 11 females. We managed to identify all previously found mutations by means of HR-MCA, which provided its validation. Furthermore, 17 different pathogenic mutations were found in the screening group, of which 10 were novel. Our results provide validation of HR-MCA as a powerful and inexpensive pre-sequencing scanning method. This technology is now ready for routine diagnostic use on DMD/BMD patients and female carriers.
Collapse
|