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Mucha O, Myszka M, Podkalicka P, Świderska B, Malinowska A, Dulak J, Łoboda A. Proteome Profiling of the Dystrophic mdx Mice Diaphragm. Biomolecules 2023; 13:1648. [PMID: 38002330 PMCID: PMC10669179 DOI: 10.3390/biom13111648] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/02/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Mdx mice with a spontaneous mutation in exon 23 of the Dmd gene represent the most common model to investigate the pathophysiology of Duchenne muscular dystrophy (DMD). The disease, caused by the lack of functional dystrophin, is characterized by irreversible impairment of muscle functions, with the diaphragm affected earlier and more severely than other skeletal muscles. We applied a label-free (LF) method and the more thorough tandem mass tag (TMT)-based method to analyze differentially expressed proteins in the diaphragm of 6-week-old mdx mice. The comparison of both methods revealed 88 commonly changed proteins. A more in-depth analysis of the TMT-based method showed 953 significantly changed proteins, with 867 increased and 86 decreased in dystrophic animals (q-value < 0.05, fold-change threshold: 1.5). Consequently, several dysregulated processes were demonstrated, including the immune response, fibrosis, translation, and programmed cell death. Interestingly, in the dystrophic diaphragm, we found a significant decrease in the expression of enzymes generating hydrogen sulfide (H2S), suggesting that alterations in the metabolism of this gaseous mediator could modulate DMD progression, which could be a potential target for pharmacological intervention.
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Affiliation(s)
- Olga Mucha
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Krakow, Gronostajowa 7 Street, 30-387 Kraków, Poland; (O.M.); (M.M.); (P.P.); (J.D.)
| | - Małgorzata Myszka
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Krakow, Gronostajowa 7 Street, 30-387 Kraków, Poland; (O.M.); (M.M.); (P.P.); (J.D.)
- Doctoral School of Exact and Natural Sciences, Łojasiewicza 11 Street, 30-348 Kraków, Poland
| | - Paulina Podkalicka
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Krakow, Gronostajowa 7 Street, 30-387 Kraków, Poland; (O.M.); (M.M.); (P.P.); (J.D.)
| | - Bianka Świderska
- Mass Spectrometry Laboratory, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a Street, 02-106 Warsaw, Poland; (B.Ś.); (A.M.)
| | - Agata Malinowska
- Mass Spectrometry Laboratory, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a Street, 02-106 Warsaw, Poland; (B.Ś.); (A.M.)
| | - Józef Dulak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Krakow, Gronostajowa 7 Street, 30-387 Kraków, Poland; (O.M.); (M.M.); (P.P.); (J.D.)
| | - Agnieszka Łoboda
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Krakow, Gronostajowa 7 Street, 30-387 Kraków, Poland; (O.M.); (M.M.); (P.P.); (J.D.)
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Preethy S, Yamamoto N, Ozasa S, Raghavan K, Dedeepiya VD, Iwasaki M, Abraham SJK. Re-examination of therapeutic management of muscular dystrophies using a vascular smooth muscle-centered approach. J Smooth Muscle Res 2023; 59:67-80. [PMID: 37673649 PMCID: PMC10482562 DOI: 10.1540/jsmr.59.67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/22/2023] [Indexed: 09/08/2023] Open
Abstract
In contrast to the long-standing focus on the pathophysiology of skeletal muscles in the hunt for a cure for Duchenne muscular dystrophy (DMD), we opine that the malfunctioning of dystrophin produced by vascular smooth muscle is a major contributor to the pathology of the illness. We believe that a biological response modifier glucan (BRMG), which has been shown in clinical studies of DMD to boost the expression of vascular smooth muscle dystrophin and provide anti-fibrotic and anti-inflammatory effects, may play a key role in reducing the pathogenesis of DMD. According to the evaluation of biomarkers, this BRMG, which is safe and side-effect-free, reduces the pathogenesis of DMD. We describe the possible mechanisms of action by which this BRMG helps in alleviating the symptoms of DMD by targeting smooth muscle dystrophin, in addition to its advantages over other therapeutic modalities, as well as how it can serve as a valuable adjunct to existing therapies. We suggest that using BRMG adjuncts that target smooth muscle dystrophin would be a potential therapeutic approach that prolongs the lifespan and extends the duration of ambulation from the onset of DMD. Further studies are needed to validate this hypothesis.
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Affiliation(s)
- Senthilkumar Preethy
- Fujio-Eiji Academic Terrain (FEAT), Nichi-In Centre for
Regenerative Medicine (NCRM), B-34, LICET, Loyola College, Nungambakkam, Chennai 600034,
India
| | - Naoki Yamamoto
- Genome Medical Sciences Project, National Center for Global
Health and Medicine (NCGM), 1 Chome-7-1 Kounodai, Ichikawa-shi, Chiba 272-8516,
Japan
| | - Shiro Ozasa
- Department of Pediatrics, Kumamoto University Hospital, 1
Chome-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Kadalraja Raghavan
- Department of Paediatric Neurology, Jesuit Antonyraj Memorial
Inter-disciplinary Centre for Advanced Recovery and Education (JAICARE), Mandela Nagar,
Madurai, Tamil Nadu 625022, India
- Department of Paediatric Neurology, Sarvee Integra Private
Limited, 61 Bhimasena Garden Street, Mylapore, Chennai 600004, India
| | - Vidyasagar Devaprasad Dedeepiya
- Mary-Yoshio Translational Hexagon (MYTH), Nichi-In Centre for
Regenerative Medicine (NCRM), C-30 LICET, Loyola College, Nungambakkam, Chennai 600034,
Chennai, India
| | - Masaru Iwasaki
- Centre for Advancing Clinical Research (CACR), School of
Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Samuel JK Abraham
- Fujio-Eiji Academic Terrain (FEAT), Nichi-In Centre for
Regenerative Medicine (NCRM), B-34, LICET, Loyola College, Nungambakkam, Chennai 600034,
India
- Mary-Yoshio Translational Hexagon (MYTH), Nichi-In Centre for
Regenerative Medicine (NCRM), C-30 LICET, Loyola College, Nungambakkam, Chennai 600034,
Chennai, India
- Centre for Advancing Clinical Research (CACR), School of
Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
- Antony-Xavier Interdisciplinary Scholastics (AXIS), GN
Corporation Co. Ltd., 3-8 Wakamatsu, Kofu, Yamanashi 400-0866, Japan
- R & D, Sophy Inc., 248 Tamura, Niyodogawa, Agawa, Kochi
781-1522, Japan
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Abstract
Viltolarsen is a phosphorodiamidate morpholino antisense oligonucleotide (PMO) designed to skip exon 53 of the DMD gene for the treatment of Duchenne muscular dystrophy (DMD), one of the most common lethal genetic disorders characterized by progressive degeneration of skeletal muscles and cardiomyopathy. It was developed by Nippon Shinyaku in collaboration with the National Center of Neurology and Psychiatry (NCNP) in Japan based on the preclinical studies conducted in the DMD dog model at the NCNP. After showing hopeful results in pre-clinical trials and several clinical trials across North America and Japan, it received US Food and Drug Administration (FDA) approval for DMD in 2020. Viltolarsen restores the reading frame of the DMD gene by skipping exon 53 and produces a truncated but functional form of dystrophin. It can treat approximately 8-10% of the DMD patient population. This paper aims to summarize the development of viltolarsen from preclinical trials to clinical trials to, finally, FDA approval, and discusses the challenges that come with fighting DMD using antisense therapy.
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Affiliation(s)
- Rohini Roy Roshmi
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.
- The Friends of Garrett Cumming Research & Muscular Dystrophy Canada, HM Toupin Neurological Science Research Chair, Edmonton, Canada.
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Dubinin MV, Starinets VS, Belosludtseva NV, Mikheeva IB, Chelyadnikova YA, Igoshkina AD, Vafina AB, Vedernikov AA, Belosludtsev KN. BK Ca Activator NS1619 Improves the Structure and Function of Skeletal Muscle Mitochondria in Duchenne Dystrophy. Pharmaceutics 2022; 14:2336. [PMID: 36365155 PMCID: PMC9696041 DOI: 10.3390/pharmaceutics14112336] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/20/2022] [Accepted: 10/26/2022] [Indexed: 08/27/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a progressive hereditary disease caused by the absence of the dystrophin protein. This is secondarily accompanied by a dysregulation of ion homeostasis, in which mitochondria play an important role. In the present work, we show that mitochondrial dysfunction in the skeletal muscles of dystrophin-deficient mdx mice is accompanied by a reduction in K+ transport and a decrease in its content in the matrix. This is associated with a decrease in the expression of the mitochondrial large-conductance calcium-activated potassium channel (mitoBKCa) in the muscles of mdx mice, which play an important role in cytoprotection. We observed that the BKCa activator NS1619 caused a normalization of mitoBKCa expression and potassium homeostasis in the muscle mitochondria of these animals, which was accompanied by an increase in the calcium retention capacity, mitigation of oxidative stress, and improvement in mitochondrial ultrastructure. This effect of NS1619 contributed to the reduction of degeneration/regeneration cycles and fibrosis in the skeletal muscles of mdx mice as well as a normalization of sarcomere size, but had no effect on the leakage of muscle enzymes and muscle strength loss. In the case of wild-type mice, we noted the negative effect of NS1619 manifested in the inhibition of the functional activity of mitochondria and disruption of their structure, which, however, did not significantly affect the state of the skeletal muscles of the animals. This article discusses the role of mitoBKCa in the development of DMD and the prospects of the approach associated with the correction of its function in treatments of this secondary channelopathy.
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Affiliation(s)
- Mikhail V. Dubinin
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Vlada S. Starinets
- Laboratory of Mitochondrial Transport, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia
| | - Natalia V. Belosludtseva
- Laboratory of Mitochondrial Transport, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia
| | - Irina B. Mikheeva
- Laboratory of Mitochondrial Transport, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia
| | - Yuliya A. Chelyadnikova
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Anastasia D. Igoshkina
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Aliya B. Vafina
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Alexander A. Vedernikov
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
| | - Konstantin N. Belosludtsev
- Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia
- Laboratory of Mitochondrial Transport, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia
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Animal models for researching approaches to therapy of Duchenne muscular dystrophy. Transgenic Res 2021; 30:709-725. [PMID: 34409525 DOI: 10.1007/s11248-021-00278-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/11/2021] [Indexed: 01/17/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a relatively widespread genetic disease which develops as a result of a mutation in the gene DMD encoding dystrophin. In this review, animal models of DMD are described. These models are used in preclinical studies to elucidate the pathogenesis of the disease or to develop effective treatments; each animal model has its own advantages and disadvantages. For instance, Caenorhabditis elegans, Drosophila melanogaster, and zebrafish (sapje) are suitable for large-scale chemical screening of large numbers of small molecules, but their disease phenotype differs from that of mammals. The use of larger animals is important for understanding of the potential efficacy of various treatments for DMD. While mdx mice have their advantages, they exhibit a milder disease phenotype compared to humans or dogs, making it difficult to evaluate the efficacy of new treatment for DMD. The disease in dogs and pigs is more severe and progresses faster than in mice, but it is more difficult to breed and obtain sufficient numbers of specimens in order to achieve statistically significant results. Moreover, working with large animals is also more labor-intensive. Therefore, when choosing the optimal animal model for research, it is worth considering all the goals and objectives.
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Veeger TTJ, van Zwet EW, Al Mohamad D, Naarding KJ, van de Velde NM, Hooijmans MT, Webb AG, Niks EH, de Groot JH, Kan HE. Muscle architecture is associated with muscle fat replacement in Duchenne and Becker muscular dystrophies. Muscle Nerve 2021; 64:576-584. [PMID: 34383334 PMCID: PMC9290788 DOI: 10.1002/mus.27399] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 08/02/2021] [Accepted: 08/07/2021] [Indexed: 12/21/2022]
Abstract
INTRODUCTION/AIMS Duchenne and Becker muscular dystrophies (DMD and BMD, respectively) are characterized by fat replacement of different skeletal muscles in a specific temporal order. Given the structural role of dystrophin in skeletal muscle mechanics, muscle architecture could be important in the progressive pathophysiology of muscle degeneration. Therefore, the aim of this study was to assess the role of muscle architecture in the progression of fat replacement in DMD and BMD. METHODS We assessed the association between literature-based leg muscle architectural characteristics and muscle fat fraction from 22 DMD and 24 BMD patients. Dixon-based magnetic resonance imaging estimates of fat fractions at baseline and 12 (only DMD) and 24 months were related to fiber length and physiological cross-sectional area (PCSA) using age-controlled linear mixed modeling. RESULTS DMD and BMD muscles with long fibers and BMD muscles with large PCSAs were associated with increased fat fraction. The effect of fiber length was stronger in muscles with larger PCSA. DISCUSSION Muscle architecture may explain the pathophysiology of muscle degeneration in dystrophinopathies, in which proximal muscles with a larger mass (fiber length × PCSA) are more susceptible, confirming the clinical observation of a temporal proximal-to-distal progression. These results give more insight into the mechanical role in the pathophysiology of muscular dystrophies. Ultimately, this new information can be used to help support the selection of current and the development of future therapies.
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Affiliation(s)
- Thom T J Veeger
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Erik W van Zwet
- Department of Biostatistics, Leiden University Medical Center, Leiden, The Netherlands
| | - Diaa Al Mohamad
- Department of Biostatistics, Leiden University Medical Center, Leiden, The Netherlands
| | - Karin J Naarding
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Melissa T Hooijmans
- Department of Radiology & Nuclear Medicine, Amsterdam University Medical Centers, Location AMC, Amsterdam, The Netherlands
| | - Andrew G Webb
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Erik H Niks
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jurriaan H de Groot
- Department of Rehabilitation Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Hermien E Kan
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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Medina-Moreno A, Henríquez JP. Maturation of a postsynaptic domain: Role of small Rho GTPases in organising nicotinic acetylcholine receptor aggregates at the vertebrate neuromuscular junction. J Anat 2021; 241:1148-1156. [PMID: 34342888 DOI: 10.1111/joa.13526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/15/2021] [Accepted: 07/20/2021] [Indexed: 12/13/2022] Open
Abstract
The neuromuscular junction (NMJ) is the peripheral synapse formed between a motor axon and a skeletal muscle fibre that allows muscle contraction and the coordinated movement in many species. A main hallmark of the mature NMJ is the assembly of nicotinic acetylcholine receptor (nAChR) aggregates in the muscle postsynaptic domain, that distributes in perfect apposition to presynaptic motor terminals. To assemble its unique functional architecture, initial embryonic NMJs undergo an early postnatal maturation process characterised by the transformation of homogenous nAChR-containing plaques to elaborate and branched pretzel-like structures. In spite of a detailed morphological characterisation, the molecular mechanisms controlling the intracellular scaffolding that organises a postsynaptic domain at the mature NMJ have not been fully elucidated. In this review, we integrate evidence of key processes and molecules that have shed light on our current understanding of the NMJ maturation process. On the one hand, we consider in vitro studies revealing the potential role of podosome-like structures to define discrete low nAChR-containing regions to consolidate a plaque-to-pretzel transition at the NMJ. On the other hand, we focus on in vitro and in vivo evidence demonstrating that members of the Ras homologous (Rho) protein family of small GTPases (small Rho GTPases) play indispensable roles on NMJ maturation by regulating the stability of nAChR aggregates. We combine this evidence to propose that small Rho GTPases are key players in the assembly of podosome-like structures that drive the postsynaptic maturation of vertebrate NMJs.
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Affiliation(s)
- Angelymar Medina-Moreno
- Laboratory of Neuromuscular Studies (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
| | - Juan Pablo Henríquez
- Laboratory of Neuromuscular Studies (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
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Florczyk-Soluch U, Polak K, Dulak J. The multifaceted view of heart problem in Duchenne muscular dystrophy. Cell Mol Life Sci 2021; 78:5447-5468. [PMID: 34091693 PMCID: PMC8257522 DOI: 10.1007/s00018-021-03862-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/29/2021] [Accepted: 05/20/2021] [Indexed: 12/14/2022]
Abstract
Dystrophin is a large protein serving as local scaffolding repetitively bridging cytoskeleton and the outside of striated muscle cell. As such dystrophin is a critical brick primarily in dystrophin-associated protein complex (DAGC) and in a larger submembranous unit, costamere. Accordingly, the lack of functional dystrophin laying at the root of Duchenne muscular dystrophy (DMD) drives sarcolemma instability. From this point on, the cascade inevitably leading to the death of myocyte begins. In cardiomyocytes, intracellular calcium overload and related mitochondrial-mediated cell death mainly contribute to myocardial dysfunction and dilation while other protein dysregulation and/or mislocalization may affect electrical conduction system and favor arrhythmogenesis. Although clinically DMD manifests as progressive muscle weakness and skeletal muscle symptoms define characteristic of DMD, it is the heart problem the biggest challenge that most often develop in the form of dilated cardiomyopathy (DCM). Current standards of treatment and recent progress in respiratory care, introduced in most settings in the 1990s, have improved quality of life and median life expectancy to 4th decade of patient's age. At the same time, cardiac causes of death related to DMD increases. Despite preventive and palliative cardiac treatments available, the prognoses remain poor. Direct therapeutic targeting of dystrophin deficiency is critical, however, hindered by the large size of the dystrophin cDNA and/or stochastic, often extensive genetic changes in DMD gene. The correlation between cardiac involvement and mutations affecting specific dystrophin isoforms, may provide a mutation-specific cardiac management and novel therapeutic approaches for patients with CM. Nonetheless, the successful cardiac treatment poses a big challenge and may require combined therapy to combat dystrophin deficiency and its after-effects (critical in DMD pathogenesis). This review locates the multifaceted heart problem in the course of DMD, balancing the insights into basic science, translational efforts and clinical manifestation of dystrophic heart disease.
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Affiliation(s)
- Urszula Florczyk-Soluch
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
| | - Katarzyna Polak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Józef Dulak
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
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Age-Dependent Dysregulation of Muscle Vasculature and Blood Flow Recovery after Hindlimb Ischemia in the mdx Model of Duchenne Muscular Dystrophy. Biomedicines 2021; 9:biomedicines9050481. [PMID: 33925757 PMCID: PMC8145677 DOI: 10.3390/biomedicines9050481] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/23/2021] [Indexed: 02/04/2023] Open
Abstract
Duchenne muscular dystrophy (DMD), caused by a lack of functional dystrophin, is characterized by progressive muscle degeneration. Interestingly, dystrophin is also expressed in endothelial cells (ECs), and insufficient angiogenesis has already been hypothesized to contribute to DMD pathology, however, its status in mdx mice, a model of DMD, is still not fully clear. Our study aimed to reveal angiogenesis-related alterations in skeletal muscles of mdx mice compared to wild-type (WT) counterparts. By investigating 6- and 12-week-old mice, we sought to verify if those changes are age-dependent. We utilized a broad spectrum of methods ranging from gene expression analysis, flow cytometry, and immunofluorescence imaging to determine the level of angiogenic markers and to assess muscle blood vessel abundance. Finally, we implemented the hindlimb ischemia (HLI) model, more biologically relevant in the context of functional studies evaluating angiogenesis/arteriogenesis processes. We demonstrated that both 6- and 12-week-old dystrophic mice exhibited dysregulation of several angiogenic factors, including decreased vascular endothelial growth factor A (VEGF) in different muscle types. Nonetheless, in younger, 6-week-old mdx animals, neither the abundance of CD31+α-SMA+ double-positive blood vessels nor basal blood flow and its restoration after HLI was affected. In 12-week-old mdx mice, although a higher number of CD31+α-SMA+ double-positive blood vessels and an increased percentage of skeletal muscle ECs were found, the abundance of pericytes was diminished, and blood flow was reduced. Moreover, impeded perfusion recovery after HLI associated with a blunted inflammatory and regenerative response was evident in 12-week-old dystrophic mice. Hence, our results reinforce the hypothesis of age-dependent angiogenic dysfunction in dystrophic mice. In conclusion, we suggest that older mdx mice constitute an appropriate model for preclinical studies evaluating the effectiveness of vascular-based therapies aimed at the restoration of functional angiogenesis to mitigate DMD severity.
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Starosta A, Konieczny P. Therapeutic aspects of cell signaling and communication in Duchenne muscular dystrophy. Cell Mol Life Sci 2021; 78:4867-4891. [PMID: 33825942 PMCID: PMC8233280 DOI: 10.1007/s00018-021-03821-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/26/2021] [Accepted: 03/23/2021] [Indexed: 12/11/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a devastating chromosome X-linked disease that manifests predominantly in progressive skeletal muscle wasting and dysfunctions in the heart and diaphragm. Approximately 1/5000 boys and 1/50,000,000 girls suffer from DMD, and to date, the disease is incurable and leads to premature death. This phenotypic severity is due to mutations in the DMD gene, which result in the absence of functional dystrophin protein. Initially, dystrophin was thought to be a force transducer; however, it is now considered an essential component of the dystrophin-associated protein complex (DAPC), viewed as a multicomponent mechanical scaffold and a signal transduction hub. Modulating signal pathway activation or gene expression through epigenetic modifications has emerged at the forefront of therapeutic approaches as either an adjunct or stand-alone strategy. In this review, we propose a broader perspective by considering DMD to be a disease that affects myofibers and muscle stem (satellite) cells, as well as a disorder in which abrogated communication between different cell types occurs. We believe that by taking this systemic view, we can achieve safe and holistic treatments that can restore correct signal transmission and gene expression in diseased DMD tissues.
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Affiliation(s)
- Alicja Starosta
- Faculty of Biology, Institute of Human Biology and Evolution, Adam Mickiewicz University, ul. Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
| | - Patryk Konieczny
- Faculty of Biology, Institute of Human Biology and Evolution, Adam Mickiewicz University, ul. Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland.
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Maruyama R, Yokota T. Antisense Oligonucleotide Treatment in a Humanized Mouse Model of Duchenne Muscular Dystrophy and Highly Sensitive Detection of Dystrophin Using Western Blotting. Methods Mol Biol 2021; 2224:203-214. [PMID: 33606217 DOI: 10.1007/978-1-0716-1008-4_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a devastating X-linked muscle disorder affecting many children. The disease is caused by the lack of dystrophin production and characterized by muscle wasting. The most common causes of death are respiratory failure and heart failure. Antisense oligonucleotide-mediated exon skipping using a phosphorodiamidate morpholino oligomer (PMO) is a promising therapeutic approach for the treatment of DMD. In preclinical studies, dystrophic mouse models are commonly used for the development of therapeutic oligos. We employ a humanized model carrying the full-length human DMD transgene along with the complete knockout of the mouse Dmd gene. In this model, the effects of human-targeting AOs can be tested without cross-reaction between mouse sequences and human sequences (note that mdx, a conventional dystrophic mouse model, carries a nonsense point mutation in exon 23 and express the full-length mouse Dmd mRNA, which is a significant complicating factor). To determine if dystrophin expression is restored, the Western blotting analysis is commonly performed; however, due to the extremely large protein size of dystrophin (427 kDa), detection and accurate quantification of full-length dystrophin can be a challenge. Here, we present methodologies to systemically inject PMOs into humanized DMD model mice and determine levels of dystrophin restoration via Western blotting. Using a tris-acetate gradient SDS gel and semi-dry transfer with three buffers, including the Concentrated Anode Buffer, Anode Buffer, and Cathode Buffer, less than 1% normal levels of dystrophin expression are easily detectable. This method is fast, easy, and sensitive enough for the detection of dystrophin from both cultured muscle cells and muscle biopsy samples.
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Affiliation(s)
- Rika Maruyama
- Faculty of Medicine and Dentistry, Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Faculty of Medicine and Dentistry, Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada. .,The Friends of Garrett Cumming Research & Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada.
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Dowling P, Gargan S, Murphy S, Zweyer M, Sabir H, Swandulla D, Ohlendieck K. The Dystrophin Node as Integrator of Cytoskeletal Organization, Lateral Force Transmission, Fiber Stability and Cellular Signaling in Skeletal Muscle. Proteomes 2021; 9:9. [PMID: 33540575 PMCID: PMC7931087 DOI: 10.3390/proteomes9010009] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/22/2021] [Accepted: 01/27/2021] [Indexed: 12/13/2022] Open
Abstract
The systematic bioanalytical characterization of the protein product of the DMD gene, which is defective in the pediatric disorder Duchenne muscular dystrophy, led to the discovery of the membrane cytoskeletal protein dystrophin. Its full-length muscle isoform Dp427-M is tightly linked to a sarcolemma-associated complex consisting of dystroglycans, sarcoglyans, sarcospan, dystrobrevins and syntrophins. Besides these core members of the dystrophin-glycoprotein complex, the wider dystrophin-associated network includes key proteins belonging to the intracellular cytoskeleton and microtubular assembly, the basal lamina and extracellular matrix, various plasma membrane proteins and cytosolic components. Here, we review the central role of the dystrophin complex as a master node in muscle fibers that integrates cytoskeletal organization and cellular signaling at the muscle periphery, as well as providing sarcolemmal stabilization and contractile force transmission to the extracellular region. The combination of optimized tissue extraction, subcellular fractionation, advanced protein co-purification strategies, immunoprecipitation, liquid chromatography and two-dimensional gel electrophoresis with modern mass spectrometry-based proteomics has confirmed the composition of the core dystrophin complex at the sarcolemma membrane. Importantly, these biochemical and mass spectrometric surveys have identified additional members of the wider dystrophin network including biglycan, cavin, synemin, desmoglein, tubulin, plakoglobin, cytokeratin and a variety of signaling proteins and ion channels.
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Affiliation(s)
- Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, W23F2H6 Maynooth, Co. Kildare, Ireland; (P.D.); (S.G.)
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, W23F2H6 Maynooth, Co. Kildare, Ireland
| | - Stephen Gargan
- Department of Biology, Maynooth University, National University of Ireland, W23F2H6 Maynooth, Co. Kildare, Ireland; (P.D.); (S.G.)
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, W23F2H6 Maynooth, Co. Kildare, Ireland
| | - Sandra Murphy
- Newcastle Fibrosis Research Group, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE24HH, UK;
| | - Margit Zweyer
- Department of Neonatology and Paediatric Intensive Care, Children’s Hospital, University of Bonn, D53113 Bonn, Germany; (M.Z.); (H.S.)
| | - Hemmen Sabir
- Department of Neonatology and Paediatric Intensive Care, Children’s Hospital, University of Bonn, D53113 Bonn, Germany; (M.Z.); (H.S.)
| | - Dieter Swandulla
- Institute of Physiology II, University of Bonn, D53115 Bonn, Germany;
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, W23F2H6 Maynooth, Co. Kildare, Ireland; (P.D.); (S.G.)
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, W23F2H6 Maynooth, Co. Kildare, Ireland
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Gorza L, Sorge M, Seclì L, Brancaccio M. Master Regulators of Muscle Atrophy: Role of Costamere Components. Cells 2021; 10:cells10010061. [PMID: 33401549 PMCID: PMC7823551 DOI: 10.3390/cells10010061] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 12/28/2020] [Accepted: 12/29/2020] [Indexed: 12/11/2022] Open
Abstract
The loss of muscle mass and force characterizes muscle atrophy in several different conditions, which share the expression of atrogenes and the activation of their transcriptional regulators. However, attempts to antagonize muscle atrophy development in different experimental contexts by targeting contributors to the atrogene pathway showed partial effects in most cases. Other master regulators might independently contribute to muscle atrophy, as suggested by our recent evidence about the co-requirement of the muscle-specific chaperone protein melusin to inhibit unloading muscle atrophy development. Furthermore, melusin and other muscle mass regulators, such as nNOS, belong to costameres, the macromolecular complexes that connect sarcolemma to myofibrils and to the extracellular matrix, in correspondence with specific sarcomeric sites. Costameres sense a mechanical load and transduce it both as lateral force and biochemical signals. Recent evidence further broadens this classic view, by revealing the crucial participation of costameres in a sarcolemmal “signaling hub” integrating mechanical and humoral stimuli, where mechanical signals are coupled with insulin and/or insulin-like growth factor stimulation to regulate muscle mass. Therefore, this review aims to enucleate available evidence concerning the early involvement of costamere components and additional putative master regulators in the development of major types of muscle atrophy.
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Affiliation(s)
- Luisa Gorza
- Department of Biomedical Sciences, University of Padova, 35121 Padova, Italy
- Correspondence:
| | - Matteo Sorge
- Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy; (M.S.); (L.S.); (M.B.)
| | - Laura Seclì
- Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy; (M.S.); (L.S.); (M.B.)
| | - Mara Brancaccio
- Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy; (M.S.); (L.S.); (M.B.)
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Brusa R, Magri F, Bresolin N, Comi GP, Corti S. Noncoding RNAs in Duchenne and Becker muscular dystrophies: role in pathogenesis and future prognostic and therapeutic perspectives. Cell Mol Life Sci 2020; 77:4299-4313. [PMID: 32350552 PMCID: PMC11105074 DOI: 10.1007/s00018-020-03537-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 04/16/2020] [Accepted: 04/21/2020] [Indexed: 12/14/2022]
Abstract
Noncoding RNAs (ncRNAs), such as miRNAs and long noncoding RNAs, are key regulators of gene expression at the post-transcriptional level and represent promising therapeutic targets and biomarkers for several human diseases, including Duchenne and Becker muscular dystrophies (DMD/BMD). A role for ncRNAs in the pathogenesis of muscular dystrophies has been suggested, even if it is still incompletely understood. Here, we discuss current progress leading towards the clinical utility of ncRNAs for DMD/BMD. Long and short noncoding RNAs are differentially expressed in DMD/BMD and have a mechanism of action via targeting mRNAs. A subset of muscle-enriched miRNAs, the so-called myomiRs (miR-1, miR-133, and miR-206), are increased in the serum of patients with DMD and in dystrophin-defective animal models. Interestingly, myomiRs might be used as biomarkers, given that their levels can be corrected after dystrophin restoration in dystrophic mice. Remarkably, further evidence demonstrates that ncRNAs also play a role in dystrophin expression; thus, their modulations might represent a potential therapeutic strategy with the aim of upregulating the dystrophin protein in combination with other oligonucleotides/gene therapy approaches.
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Affiliation(s)
- Roberta Brusa
- Neurology Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesca Magri
- Neurology Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Nereo Bresolin
- Neurology Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
| | - Giacomo Pietro Comi
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
- Neuromuscular and Rare Diseases Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Stefania Corti
- Neurology Unit, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy.
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Thangarajh M, Elfring GL, Trifillis P. Longitudinal Evaluation of Working Memory in Duchenne Muscular Dystrophy. J Clin Med 2020; 9:jcm9092940. [PMID: 32933029 PMCID: PMC7563441 DOI: 10.3390/jcm9092940] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/16/2020] [Accepted: 09/02/2020] [Indexed: 01/16/2023] Open
Abstract
Objective: The developmental maturation of forward and backward digit spans—indices of working memory—in boys with nonsense (nm) Duchenne muscular dystrophy (DMD) (nmDMD) was assessed using prospective, longitudinal data. Methods: Fifty-five boys of the 57 subjects with genetically confirmed nmDMD—who were from the placebo arm of a 48-week-long phase 2b clinical trial—were evaluated. Forward and backward digit spans were obtained every 12 weeks for a total of five assessments in all study subjects. Changes in forward and backward digit spans were evaluated based on age, corticosteroid treatment, and DMD mutation location. Results: Boys with nmDMD had lower mean scores on normalized forward digit span. Normalized forward digit spans were comparable between subjects stratified by age and between corticosteroid-naïve and corticosteroid-treated subjects. When stratified by DMD mutation location, normalized forward digit spans were lower in nmDMD subjects with mutations downstream of DMD exon 30, exon 45, and exon 63, both at baseline evaluation and at follow-up evaluation at 48 weeks. On average, normalized backward digit span scores were stable over 48 weeks in these subjects. Developmental growth modeling showed that subjects with nmDMD mutations upstream of DMD exon 30, upstream of DMD exon 45, and upstream of DMD exon 63 appeared to make better gains in working memory than subjects with mutations downstream of DMD exon 30, downstream of DMD exon 45, and downstream of DMD exon 63. Conclusion: Performance in working memory shows deficits in nmDMD and differed based on nmDMD location. Maturation in cognition was seen over a 48-week period. The developmental trajectory of working memory in this cohort was influenced by DMD mutation location.
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Affiliation(s)
- Mathula Thangarajh
- Department of Neurology, Virginia Commonwealth University, 1101 East Marshall Street, P.O. Box 980599, Richmond, VA 23298, USA
- Correspondence: ; Tel.: +1-804-628-0396
| | - Gary L. Elfring
- PTC Therapeutics Inc., South Plainfield, NJ 07080, USA; (G.L.E.); (P.T.)
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Morpholino Oligomer-Induced Dystrophin Isoforms to Map the Functional Domains in the Dystrophin Protein. MOLECULAR THERAPY-NUCLEIC ACIDS 2020; 22:263-272. [PMID: 33230432 PMCID: PMC7516190 DOI: 10.1016/j.omtn.2020.08.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 08/18/2020] [Indexed: 12/21/2022]
Abstract
Dystrophin plays a crucial role in maintaining sarcolemma stability during muscle contractions, and mutations that prevent the expression of a functional protein cause Duchenne muscular dystrophy (DMD). Antisense oligonucleotide-mediated manipulation of pre-messenger RNA splicing to bypass Duchenne-causing mutations and restore functional dystrophin expression has entered the clinic for the most common DMD mutations. The rationale of "exon skipping" is based upon genotype-phenotype correlations observed in Becker muscular dystrophy, a milder allelic disorder generally characterized by in-frame deletions and internally truncated but semi-functional dystrophin isoforms. However, there is a lack of genotype-phenotype correlations downstream of DMD exon 55, as deletions in this region are rare and most single exon deletions would disrupt the reading frame. Consequently, the amenability of mutations in this region of the DMD gene to exon skipping strategies remains unknown. Here, we induced "Becker muscular dystrophy-like" in-frame dystrophin isoforms in vivo by intraperitoneal injection of peptide-conjugated phosphorodiamidate morpholino oligomers targeting selected exons. The dystrophin isoform encoded by the transcript lacking exons 56+57 appears to be more functional than that encoded by the 58+59-deleted transcript, as determined by higher dystrophin expression, stabilized β-dystroglycan, and less severe dystrophic pathology, indicating some potential for the strategy to address Duchenne-causing mutations affecting these exons.
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Thangarajh M, Hendriksen J, McDermott MP, Martens W, Hart KA, Griggs RC. Relationships between DMD mutations and neurodevelopment in dystrophinopathy. Neurology 2019; 93:e1597-e1604. [PMID: 31594858 DOI: 10.1212/wnl.0000000000008363] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/22/2019] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE We performed a prospective, cross-sectional analysis of neurodevelopmental concerns and psychosocial adjustment in relation to DMD mutations in young steroid-naive boys with dystrophinopathy. METHODS We evaluated 196 steroid-naive boys with dystrophinopathy who were enrolled in the Finding the Optimal Regimen for Duchenne Muscular Dystrophy trial. The neurodevelopmental concerns and psychosocial adjustment challenges were analyzed in relation to DMD mutation. A parent or legal guardian reported neurodevelopmental concerns in 4 domains (speech, learning and attentional difficulties, and autism spectrum disorder [ASD]) and completed the Personal Adjustment and Role Skills Scale to assess psychosocial adjustment. We also assessed whether boys of DMD carrier mothers were more vulnerable to speech delay and learning difficulties. RESULTS We found that 39% of boys were reported to have speech delay with a mean age of speaking at 28 months (range 7-66 months). Learning difficulties were reported in 28% of participants. Inattentive-overactive and oppositional-defiant behavior was reported in 8% and 5% of participants, respectively. Psychosocial adjustment challenges were reported in 4% of participants. An ASD diagnosis was reported in 3 participants. Speech delay and learning difficulties were more common in boys with mutations downstream of DMD exon 45. Neurodevelopmental concerns were not associated with DMD deletion, duplication, or point mutation subtype. Boys of DMD carrier mothers did not have longer speech delay or more learning difficulties. CONCLUSION Our data support evidence for a relationship between neurodevelopmental concerns and DMD mutation. A longitudinal assessment of developmental trajectory is necessary to evaluate how specific DMD mutations affect brain function.
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Affiliation(s)
- Mathula Thangarajh
- From the Department of Neurology (M.T.), Children's National Health System, Washington, DC; Kempenhaeghe Center for Neurological Learning Disabilities (J.H.), Heeze, the Netherlands; and School of Medicine and Dentistry (M.P.M., W.M., K.A.H., R.C.G.), University of Rochester Medical Center, NY. M.T. is currently affiliated with the Department of Neurology, Virginia Commonwealth University, Richmond.
| | - Jos Hendriksen
- From the Department of Neurology (M.T.), Children's National Health System, Washington, DC; Kempenhaeghe Center for Neurological Learning Disabilities (J.H.), Heeze, the Netherlands; and School of Medicine and Dentistry (M.P.M., W.M., K.A.H., R.C.G.), University of Rochester Medical Center, NY. M.T. is currently affiliated with the Department of Neurology, Virginia Commonwealth University, Richmond
| | - Michael P McDermott
- From the Department of Neurology (M.T.), Children's National Health System, Washington, DC; Kempenhaeghe Center for Neurological Learning Disabilities (J.H.), Heeze, the Netherlands; and School of Medicine and Dentistry (M.P.M., W.M., K.A.H., R.C.G.), University of Rochester Medical Center, NY. M.T. is currently affiliated with the Department of Neurology, Virginia Commonwealth University, Richmond
| | - William Martens
- From the Department of Neurology (M.T.), Children's National Health System, Washington, DC; Kempenhaeghe Center for Neurological Learning Disabilities (J.H.), Heeze, the Netherlands; and School of Medicine and Dentistry (M.P.M., W.M., K.A.H., R.C.G.), University of Rochester Medical Center, NY. M.T. is currently affiliated with the Department of Neurology, Virginia Commonwealth University, Richmond
| | - Kimberly A Hart
- From the Department of Neurology (M.T.), Children's National Health System, Washington, DC; Kempenhaeghe Center for Neurological Learning Disabilities (J.H.), Heeze, the Netherlands; and School of Medicine and Dentistry (M.P.M., W.M., K.A.H., R.C.G.), University of Rochester Medical Center, NY. M.T. is currently affiliated with the Department of Neurology, Virginia Commonwealth University, Richmond
| | - Robert C Griggs
- From the Department of Neurology (M.T.), Children's National Health System, Washington, DC; Kempenhaeghe Center for Neurological Learning Disabilities (J.H.), Heeze, the Netherlands; and School of Medicine and Dentistry (M.P.M., W.M., K.A.H., R.C.G.), University of Rochester Medical Center, NY. M.T. is currently affiliated with the Department of Neurology, Virginia Commonwealth University, Richmond
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Geisler JG. 2,4 Dinitrophenol as Medicine. Cells 2019; 8:cells8030280. [PMID: 30909602 PMCID: PMC6468406 DOI: 10.3390/cells8030280] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/11/2019] [Accepted: 03/20/2019] [Indexed: 12/20/2022] Open
Abstract
In the sanctity of pure drug discovery, objective reasoning can become clouded when pursuing ideas that appear unorthodox, but are spot on physiologically. To put this into historical perspective, it was an unorthodox idea in the 1950’s to suggest that warfarin, a rat poison, could be repositioned into a breakthrough drug in humans to protect against strokes as a blood thinner. Yet it was approved in 1954 as Coumadin® and has been prescribed to billions of patients as a standard of care. Similarly, no one can forget the horrific effects of thalidomide, prescribed or available without a prescription, as both a sleeping pill and “morning sickness” anti-nausea medication targeting pregnant women in the 1950’s. The “thalidomide babies” became the case-in-point for the need of strict guidelines by the U.S. Food & Drug Administration (FDA) or full multi-species teratogenicity testing before drug approval. More recently it was found that thalidomide is useful in graft versus host disease, leprosy and resistant tuberculosis treatment, and as an anti-angiogenesis agent as a breakthrough drug for multiple myeloma (except for pregnant female patients). Decades of diabetes drug discovery research has historically focused on every possible angle, except, the energy-out side of the equation, namely, raising mitochondrial energy expenditure with chemical uncouplers. The idea of “social responsibility” allowed energy-in agents to be explored and the portfolio is robust with medicines of insulin sensitizers, insulin analogues, secretagogues, SGLT2 inhibitors, etc., but not energy-out medicines. The primary reason? It appeared unorthodox, to return to exploring a drug platform used in the 1930s in over 100,000 obese patients used for weight loss. This is over 80-years ago and prior to Dr Peter Mitchell explaining the mechanism of how mitochondrial uncouplers, like 2,4-dinitrophenol (DNP) even worked by three decades later in 1961. Although there is a clear application for metabolic disease, it was not until recently that this platform was explored for its merit at very low, weight-neutral doses, for treating insidious human illnesses and completely unrelated to weight reduction. It is known that mitochondrial uncouplers specifically target the entire organelle’s physiology non-genomically. It has been known for years that many neuromuscular and neurodegenerative diseases are associated with overt production of reactive oxygen species (ROSs), a rise in isoprostanes (biomarker of mitochondrial ROSs in urine or blood) and poor calcium (Ca2+) handing. It has also been known that mitochondrial uncouplers lower ROS production and Ca2+ overload. There is evidence that elevation of isoprostanes precedes disease onset, in Alzheimer’s Disease (AD). It is also curious, why so many neurodegenerative diseases of known and unknown etiology start at mid-life or later, such as Multiple Sclerosis (MS), Huntington Disease (HD), AD, Parkinson Disease, and Amyotrophic Lateral Sclerosis (ALS). Is there a relationship to a buildup of mutations that are sequestered over time due to ROSs exceeding the rate of repair? If ROS production were managed, could disease onset due to aging be delayed or prevented? Is it possible that most, if not all neurodegenerative diseases are manifested through mitochondrial dysfunction? Although DNP, a historic mitochondrial uncoupler, was used in the 1930s at high doses for obesity in well over 100,000 humans, and so far, it has never been an FDA-approved drug. This review will focus on the application of using DNP, but now, repositioned as a potential disease-modifying drug for a legion of insidious diseases at much lower and paradoxically, weight neutral doses. DNP will be addressed as a treatment for “metabesity”, an emerging term related to the global comorbidities associated with the over-nutritional phenotype; obesity, diabetes, nonalcoholic steatohepatitis (NASH), metabolic syndrome, cardiovascular disease, but including neurodegenerative disorders and accelerated aging. Some unexpected drug findings will be discussed, such as DNP’s induction of neurotrophic growth factors involved in neuronal heath, learning and cognition. For the first time in 80’s years, the FDA has granted (to Mitochon Pharmaceutical, Inc., Blue Bell, PA, USA) an open Investigational New Drug (IND) approval to begin rigorous clinical testing of DNP for safety and tolerability, including for the first ever, pharmacokinetic profiling in humans. Successful completion of Phase I clinical trial will open the door to explore the merits of DNP as a possible treatment of people with many truly unmet medical needs, including those suffering from HD, MS, PD, AD, ALS, Duchenne Muscular Dystrophy (DMD), and Traumatic Brain Injury (TBI).
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Affiliation(s)
- John G Geisler
- Mitochon Pharmaceuticals, Inc., 970 Cross Lane, Blue Bell, PA 19422, USA.
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19
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Nguyen Q, Yokota T. Antisense oligonucleotides for the treatment of cardiomyopathy in Duchenne muscular dystrophy. Am J Transl Res 2019; 11:1202-1218. [PMID: 30972156 PMCID: PMC6456507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/02/2019] [Indexed: 06/09/2023]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive fatal neuromuscular disorder characterized by progressive muscle degeneration which affects one in 3500-5000 males born worldwide. DMD is caused by loss-of-function mutations in the dystrophin (DMD) gene encoding for dystrophin, a cytoskeletal protein that supports the structural integrity of myofibers during cycles of muscle contraction and relaxation. DMD patients do not only experience skeletal muscle deterioration but also severe cardiomyopathy, which is recognized as the current leading cause of death for the disease. Among the therapies being developed, exon skipping using antisense oligonucleotides (AOs) is one of the most promising approaches. AOs effectively restore dystrophin expression in skeletal muscles; however, they are highly inefficient in the heart due to endosomal entrapment. Improving skeletal muscle function without restoring dystrophin expression in cardiac tissue may exacerbate cardiomyopathy due to increased voluntary activity. This review consolidates the preclinical antisense approaches to improve dystrophin restoration, with a special focus on the heart.
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Affiliation(s)
- Quynh Nguyen
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta8812-112 St., Edmonton, AB T6G 2H7, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta8812-112 St., Edmonton, AB T6G 2H7, Canada
- The Friends of Garret Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair8812-112 St., Edmonton, AB T6G 2H7, Canada
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Lechado I Terradas A, Vitadello M, Traini L, Namuduri AV, Gastaldello S, Gorza L. Sarcolemmal loss of active nNOS (Nos1) is an oxidative stress-dependent, early event driving disuse atrophy. J Pathol 2018; 246:433-446. [PMID: 30066461 DOI: 10.1002/path.5149] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 05/28/2018] [Accepted: 07/27/2018] [Indexed: 01/08/2023]
Abstract
Skeletal muscle atrophy following unloading or immobilization represents a major invalidating event in bedridden patients. Among mechanisms involved in atrophy development, a controversial role is played by neuronal NOS (nNOS; NOS1), whose dysregulation at the protein level and/or subcellular distribution also characterizes other neuromuscular disorders. This study aimed to investigate unloading-induced changes in nNOS before any evidence of myofiber atrophy, using vastus lateralis biopsies obtained from young healthy subjects after a short bed-rest and rat soleus muscles after exposure to short unloading periods. Our results showed that (1) changes in nNOS subcellular distribution using NADPH-diaphorase histochemistry to detect enzyme activity were observed earlier than using immunofluorescence to visualize the protein; (2) loss of active nNOS from the physiological subsarcolemmal localization occurred before myofiber atrophy, i.e. in 8-day bed-rest biopsies and in 6 h-unloaded rat soleus, and was accompanied by increased nNOS activity in the sarcoplasm; (3) nNOS (Nos1) transcript and protein levels decreased significantly in the rat soleus after 6 h and 1 day unloading, respectively, to return to ambulatory levels after 4 and 7 days of unloading, respectively; (4) unloading-induced nNOS redistribution appeared dependent on mitochondrial-derived oxidant species, indirectly measured by tropomyosin disulfide bonds which had increased significantly in the rat soleus already after a 6 h-unloading bout; (5) activity of displaced nNOS molecules is required for translocation of the FoxO3 transcription factor to myofiber nuclei. FoxO3 nuclear localization in rat soleus increased after 6 h unloading (about four-fold the ambulatory level), whereas it did not when nNOS expression and activity were inhibited in vivo before and during 6 h unloading. In conclusion, this study demonstrates that the redistribution of active nNOS molecules from sarcolemma to sarcoplasm not only is ahead of the atrophy of unloaded myofibers, and is induced by increased production of mitochondrial superoxide anion, but also drives FoxO3 activation to initiate muscle atrophy. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
| | | | - Leonardo Traini
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | | | - Stefano Gastaldello
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.,Precision Medicine Research Center (Department), Binzhou Medical University, Shandong Province, Yantai, PR China
| | - Luisa Gorza
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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Photoswitchable peptide-based ‘on-off’ biosensor for electrochemical detection and control of protein-protein interactions. Biosens Bioelectron 2018; 118:188-194. [DOI: 10.1016/j.bios.2018.07.057] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/26/2018] [Accepted: 07/27/2018] [Indexed: 12/24/2022]
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Lindberg U, Kruuse C, Witting N, Jørgensen SL, Vissing J, Rostrup E, Larsson HBW. Altered somatosensory neurovascular response in patients with Becker muscular dystrophy. Brain Behav 2018; 8:e00985. [PMID: 30106246 PMCID: PMC5991560 DOI: 10.1002/brb3.985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 02/12/2018] [Accepted: 03/31/2018] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION Patients with dystrophinopathies show low levels of neuronal nitric oxide synthase (nNOS), due to reduced or absent dystrophin expression, as nNOS is attached to the dystrophin-associated protein complex. Deficient nNOS function leads to functional ischemia during muscle activity. Dystrophin-like proteins with nNOS attached have also been identified in the brain. This suggests that a mechanism of cerebral functional ischemia with attenuation of normal activation-related vascular response may cause changes in brain function. METHODS The aim of this study was to investigate whether the brain response of patients with Becker muscular dystrophy (BMD) is dysfunctional compared to that of healthy controls. To investigate a potential change in brain activation response in patients with BMD, median nerve somatosensory evoked stimulation, with stimulation durations of 2, 4, and 10 s, was performed while recording electroencephalography and blood oxygen level-dependent (BOLD) functional magnetic resonance imaging. RESULTS Results in 14 male patients with BMD (36.2 ± 9.9 years) were compared with those of 10 healthy controls (34.4 ± 10.9 years). Compared to controls, the patients with BMD showed sustained cortical electrical activity and a significant smaller BOLD activation in contralateral primary somatosensory cortex and bilaterally in secondary somatosensory cortex. In addition, significant activation differences were found after long duration (10 s) stimuli in thalamus. CONCLUSION An altered neurovascular response in patients with BMD may increase our understanding of neurovascular coupling and the pathogenesis related to dystrophinopathy and nNOS.
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Affiliation(s)
- Ulrich Lindberg
- Functional Imaging UnitDepartment of Clinical PhysiologyNuclear Medicine and PETRigshospitalet GlostrupUniversity of CopenhagenGlostrupDenmark
- Lundbeck Foundation Center for Neurovascular signalling (LUCENS)Rigshospitalet GlostrupUniversity of CopenhagenGlostrupDenmark
| | - Christina Kruuse
- Lundbeck Foundation Center for Neurovascular signalling (LUCENS)Rigshospitalet GlostrupUniversity of CopenhagenGlostrupDenmark
- Neurovascular Research UnitDepartment of NeurologyHerlev Gentofte HospitalUniversity of CopenhagenHerlevDenmark
| | - Nanna Witting
- Copenhagen Neuromuscular CenterDepartment of NeurologyRigshospitaletUniversity of CopenhagenDenmark
| | - Stine Lundgaard Jørgensen
- Lundbeck Foundation Center for Neurovascular signalling (LUCENS)Rigshospitalet GlostrupUniversity of CopenhagenGlostrupDenmark
- Neurovascular Research UnitDepartment of NeurologyHerlev Gentofte HospitalUniversity of CopenhagenHerlevDenmark
| | - John Vissing
- Copenhagen Neuromuscular CenterDepartment of NeurologyRigshospitaletUniversity of CopenhagenDenmark
| | - Egill Rostrup
- Functional Imaging UnitDepartment of Clinical PhysiologyNuclear Medicine and PETRigshospitalet GlostrupUniversity of CopenhagenGlostrupDenmark
| | - Henrik Bo Wiberg Larsson
- Functional Imaging UnitDepartment of Clinical PhysiologyNuclear Medicine and PETRigshospitalet GlostrupUniversity of CopenhagenGlostrupDenmark
- Lundbeck Foundation Center for Neurovascular signalling (LUCENS)Rigshospitalet GlostrupUniversity of CopenhagenGlostrupDenmark
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23
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Lopez JR, Uryash A, Kolster J, Estève E, Zhang R, Adams JA. Enhancing Endogenous Nitric Oxide by Whole Body Periodic Acceleration Elicits Neuroprotective Effects in Dystrophic Neurons. Mol Neurobiol 2018; 55:8680-8694. [DOI: 10.1007/s12035-018-1018-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 03/16/2018] [Indexed: 12/25/2022]
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24
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Ionita C, Kinnett K, Mathews K. Collective Statement Regarding Patient Access to Approved Therapies from the Center Directors of Parent Project Muscular Dystrophy's Certified Duchenne Care Centers. PLOS CURRENTS 2018; 10:ecurrents.md.4a12c57a46a24603cb3d36d7fe0668b6. [PMID: 29623241 PMCID: PMC5878098 DOI: 10.1371/currents.md.4a12c57a46a24603cb3d36d7fe0668b6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The dystrophinopathies (Duchenne [DMD] and Becker muscular dystrophy) are progressive diseases that until recently had no specific treatments. New FDA pathways to drug approval in rare diseases have resulted in a dramatic increase in the number of treatment trials for DMD and recently, two approved drugs. Health insurance policies for DMD products have been constructed with limited input from neuromuscular specialists directly involved in patient care and without patient input. These policies often reflect a lack of understanding of the disease, clinical population or the treatment. To ensure that policy determinations reflect best clinical practice, we recommend insurers work with neuromuscular specialists with expertise in care for patients with dystrophinopathy, as well as patients and families, and prominent advocacy organizations, such as Parent Project Muscular Dystrophy, in developing policies.
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Affiliation(s)
- Cristian Ionita
- Department of Pediatrics (Neurology), Yale University School of Medicine, New Haven, CT, USA
| | - Kathi Kinnett
- Parent Project Muscular Dystrophy, MIddletown, OH, USA
| | - Katherine Mathews
- Departments of Pediatrics and Neurology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
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25
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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.
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Immortalized Muscle Cell Model to Test the Exon Skipping Efficacy for Duchenne Muscular Dystrophy. J Pers Med 2017; 7:jpm7040013. [PMID: 29035327 PMCID: PMC5748625 DOI: 10.3390/jpm7040013] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/08/2017] [Accepted: 10/08/2017] [Indexed: 01/25/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal genetic disorder that most commonly results from mutations disrupting the reading frame of the dystrophin (DMD) gene. Among the therapeutic approaches employed, exon skipping using antisense oligonucleotides (AOs) is one of the most promising strategies. This strategy aims to restore the reading frame, thus producing a truncated, yet functioning dystrophin protein. In 2016, the Food and Drug Administration (FDA) conditionally approved the first AO-based drug, eteplirsen (Exondys 51), developed for DMD exon 51 skipping. An accurate and reproducible method to quantify exon skipping efficacy is essential for evaluating the therapeutic potential of different AOs sequences. However, previous in vitro screening studies have been hampered by the limited proliferative capacity and insufficient amounts of dystrophin expressed by primary muscle cell lines that have been the main system used to evaluate AOs sequences. In this paper, we illustrate the challenges associated with primary muscle cell lines and describe a novel approach that utilizes immortalized cell lines to quantitatively evaluate the exon skipping efficacy in in vitro studies.
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27
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Aranmolate A, Tse N, Colognato H. Myelination is delayed during postnatal brain development in the mdx mouse model of Duchenne muscular dystrophy. BMC Neurosci 2017; 18:63. [PMID: 28806929 PMCID: PMC5556620 DOI: 10.1186/s12868-017-0381-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/07/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In Duchenne muscular dystrophy (DMD), the loss of the dystrophin component of the dystrophin-glycoprotein complex (DGC) compromises plasma membrane integrity in skeletal muscle, resulting in extensive muscle degeneration. In addition, many DMD patients exhibit brain deficits in which the cellular etiology remains poorly understood. We recently found that dystroglycan, a receptor component of the DGC that binds intracellularly to dystrophin, regulates the development of oligodendrocytes, the myelinating glial cells of the brain. RESULTS We investigated whether dystrophin contributes to oligodendroglial function and brain myelination. We found that oligodendrocytes express up to three dystrophin isoforms, in conjunction with classic DGC components, which are developmentally regulated during differentiation and in response to extracellular matrix engagement. We found that mdx mice, a model of DMD lacking expression of the largest dystrophin isoform, have delayed myelination and inappropriate oligodendrocyte progenitor proliferation in the cerebral cortex. When we prevented the expression of all oligodendroglial dystrophin isoforms in cultured oligodendrocytes using RNA interference, we found that later stages of oligodendrocyte maturation were significantly delayed, similar to mdx phenotypes in the developing brain. CONCLUSIONS We find that dystrophin is expressed in oligodendrocytes and influences developmental myelination, which provides new insight into potential cellular contributors to brain dysfunction associated with DMD.
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Affiliation(s)
- Azeez Aranmolate
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794-8651, USA
| | - Nathaniel Tse
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794-8651, USA
| | - Holly Colognato
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11794-8651, USA.
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28
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Lim KRQ, Maruyama R, Yokota T. Eteplirsen in the treatment of Duchenne muscular dystrophy. DRUG DESIGN DEVELOPMENT AND THERAPY 2017; 11:533-545. [PMID: 28280301 PMCID: PMC5338848 DOI: 10.2147/dddt.s97635] [Citation(s) in RCA: 294] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Duchenne muscular dystrophy is a fatal neuromuscular disorder affecting around one in 3,500–5,000 male births that is characterized by progressive muscular deterioration. It is inherited in an X-linked recessive fashion and is caused by loss-of-function mutations in the DMD gene coding for dystrophin, a cytoskeletal protein that stabilizes the plasma membrane of muscle fibers. In September 2016, the US Food and Drug Administration granted accelerated approval for eteplirsen (or Exondys 51), a drug that acts to promote dystrophin production by restoring the translational reading frame of DMD through specific skipping of exon 51 in defective gene variants. Eteplirsen is applicable for approximately 14% of patients with DMD mutations. This article extensively reviews and discusses the available information on eteplirsen to date, focusing on pharmacological, efficacy, safety, and tolerability data from preclinical and clinical trials. Issues faced by eteplirsen, particularly those relating to its efficacy, will be identified. Finally, the place of eteplirsen and exon skipping as a general therapeutic strategy in Duchenne muscular dystrophy treatment will be discussed.
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Affiliation(s)
- Kenji Rowel Q Lim
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta
| | - Rika Maruyama
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta; The Friends of Garrett Cumming Research & Muscular Dystrophy Canada, HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada
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29
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Impaired regenerative capacity and lower revertant fibre expansion in dystrophin-deficient mdx muscles on DBA/2 background. Sci Rep 2016; 6:38371. [PMID: 27924830 PMCID: PMC5141435 DOI: 10.1038/srep38371] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 11/08/2016] [Indexed: 02/06/2023] Open
Abstract
Duchenne muscular dystrophy, one of the most common lethal genetic disorders, is caused by mutations in the DMD gene and a lack of dystrophin protein. In most DMD patients and animal models, sporadic dystrophin-positive muscle fibres, called revertant fibres (RFs), are observed in otherwise dystrophin-negative backgrounds. RFs are thought to arise from skeletal muscle precursor cells and clonally expand with age due to the frequent regeneration of necrotic fibres. Here we examined the effects of genetic background on muscle regeneration and RF expansion by comparing dystrophin-deficient mdx mice on the C57BL/6 background (mdx-B6) with those on the DBA/2 background (mdx-DBA), which have a more severe phenotype. Interestingly, mdx-DBA muscles had significantly lower RF expansion than mdx-B6 in all age groups, including 2, 6, 12, and 18 months. The percentage of centrally nucleated fibres was also significantly lower in mdx-DBA mice compared to mdx-B6, indicating that less muscle regeneration occurs in mdx-DBA. Our study aligns with the model that RF expansion reflects the activity of precursor cells in skeletal muscles, and it serves as an index of muscle regeneration capacity.
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Filippini M, Guerra A, Negosanti A, Santi S, Sarajlija J, Musti MA, Gobbi G, Lassonde M, Pini A. Mismatch Negativity Recording in Children With Duchenne Muscular Dystrophy: A Preliminary Study Integrating Neurophysiological and Neuropsychological Results. J Child Neurol 2016; 31:1468-1474. [PMID: 27422795 DOI: 10.1177/0883073816656404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/26/2016] [Indexed: 11/15/2022]
Abstract
Many studies on Duchenne muscular dystrophy children support the hypothesis of a specific neuropsychological phenotype affecting mostly phonological skills. This prospective study aimed to shed light on the role of phonological abilities. Fourteen Duchenne muscular dystrophy children and 7 healthy children underwent mismatch negativity. Moreover, verbal intelligence, visuospatial attention, immediate verbal memory, working memory, grammar, vocabulary, visuomotor skills, reading, text comprehension, writing, and arithmetic were tested in Duchenne muscular dystrophy children. No significant difference between control and Duchenne muscular dystrophy children was found neither for mismatch negativity amplitude (P = .191 and .116, respectively) nor for latency (P = .135). Eight (57.14%) patients showed an impairment of immediate verbal memory and of visuomotor skills, 7 (63.64%) patients had a deficit in writing and arithmetic skills, even with a mean normal intelligence quotient. Taken together, the results put in evidence a heterogeneous neuropsychological profile not explainable on the basis of a phonological deficit.
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Affiliation(s)
- Melissa Filippini
- Child Neurology Unit, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | - Angelo Guerra
- Child Neurology Unit, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | | | - Sara Santi
- Child Neurology Unit, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | - Jasenka Sarajlija
- Child Neurology Unit, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | | | - Giuseppe Gobbi
- Child Neurology Unit, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | - Maryse Lassonde
- Department of Psychology, Université de Montréal, Montréal, Canada
| | - Antonella Pini
- Child Neurology Unit, IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
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31
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Chaudhury A. Response: "Commentary: A Hypothesis for Examining Skeletal Muscle Biopsy-Derived Sarcolemmal nNOSµ as Surrogate for Enteric nNOSα Function". nNOS(skeletal muscle) may be Evidentiary for Enteric NO-Transmission Despite nNOSµ/α Differences. Front Med (Lausanne) 2016; 3:4. [PMID: 26942180 PMCID: PMC4761842 DOI: 10.3389/fmed.2016.00004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/15/2016] [Indexed: 12/15/2022] Open
Affiliation(s)
- Arun Chaudhury
- Arkansas Department of Health and GIM Foundation , Little Rock, AR , USA
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