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Oddoux S, Randazzo D, Kenea A, Alonso B, Zaal KJM, Ralston E. Misplaced Golgi Elements Produce Randomly Oriented Microtubules and Aberrant Cortical Arrays of Microtubules in Dystrophic Skeletal Muscle Fibers. Front Cell Dev Biol 2019; 7:176. [PMID: 31620435 PMCID: PMC6759837 DOI: 10.3389/fcell.2019.00176] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/13/2019] [Indexed: 12/14/2022] Open
Abstract
Differentiated mammalian cells and tissues, such as skeletal muscle fibers, acquire an organization of Golgi complex and microtubules profoundly different from that in proliferating cells and still poorly understood. In adult rodent skeletal muscle, the multinucleated muscle fibers have hundreds of Golgi elements (GE), small stacks of cisternae that serve as microtubule-organizing centers. We are interested in the role of the GE in organizing a peculiar grid of microtubules located in the fiber cortex, against the sarcolemma. Modifications of this grid in the mdx mouse model of Duchenne muscular dystrophy have led to identifying dystrophin, the protein missing in both human disease and mouse model, as a microtubule guide. Compared to wild-type (WT), mdx microtubules are disordered and more dense and they have been linked to the dystrophic pathology. GE themselves are disordered in mdx. Here, to identify the causes of GE and microtubule alterations in the mdx muscle, we follow GFP-tagged microtubule markers in live mdx fibers and investigate the recovery of GE and microtubules after treatment with nocodazole. We find that mdx microtubules grow 10% faster but in 30% shorter bouts and that they begin to form a tangled network, rather than an orthogonal grid, right after nucleation from GE. Strikingly, a large fraction of microtubules in mdx muscle fibers seem to dissociate from GE after nucleation. Moreover, we report that mdx GE are mispositioned and increased in number and size. These results were replicated in WT fibers overexpressing the beta-tubulin tubb6, which is elevated in Duchenne muscular dystrophy, in mdx and in regenerating muscle. Finally, we examine the association of GE with ER exit sites and ER-to-Golgi intermediate compartment, which starts during muscle differentiation, and find it persisting in mdx and tubb6 overexpressing fibers. We conclude that GE are full, small, Golgi complexes anchored, and positioned through ER Exit Sites. We propose a model in which GE mispositioning, together with the absence of microtubule guidance due to the lack of dystrophin, determines the differences in GE and microtubule organization between WT and mdx muscle fibers.
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Affiliation(s)
- Sarah Oddoux
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Davide Randazzo
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Aster Kenea
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Bruno Alonso
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Kristien J M Zaal
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Evelyn Ralston
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
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52
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Ross JA, Levy Y, Ripolone M, Kolb JS, Turmaine M, Holt M, Lindqvist J, Claeys KG, Weis J, Monforte M, Tasca G, Moggio M, Figeac N, Zammit PS, Jungbluth H, Fiorillo C, Vissing J, Witting N, Granzier H, Zanoteli E, Hardeman EC, Wallgren-Pettersson C, Ochala J. Impairments in contractility and cytoskeletal organisation cause nuclear defects in nemaline myopathy. Acta Neuropathol 2019; 138:477-495. [PMID: 31218456 PMCID: PMC6689292 DOI: 10.1007/s00401-019-02034-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/28/2019] [Accepted: 06/05/2019] [Indexed: 02/07/2023]
Abstract
Nemaline myopathy (NM) is a skeletal muscle disorder caused by mutations in genes that are generally involved in muscle contraction, in particular those related to the structure and/or regulation of the thin filament. Many pathogenic aspects of this disease remain largely unclear. Here, we report novel pathological defects in skeletal muscle fibres of mouse models and patients with NM: irregular spacing and morphology of nuclei; disrupted nuclear envelope; altered chromatin arrangement; and disorganisation of the cortical cytoskeleton. Impairments in contractility are the primary cause of these nuclear defects. We also establish the role of microtubule organisation in determining nuclear morphology, a phenomenon which is likely to contribute to nuclear alterations in this disease. Our results overlap with findings in diseases caused directly by mutations in nuclear envelope or cytoskeletal proteins. Given the important role of nuclear shape and envelope in regulating gene expression, and the cytoskeleton in maintaining muscle fibre integrity, our findings are likely to explain some of the hallmarks of NM, including contractile filament disarray, altered mechanical properties and broad transcriptional alterations.
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53
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Caporizzo MA, Chen CY, Prosser BL. Cardiac microtubules in health and heart disease. Exp Biol Med (Maywood) 2019; 244:1255-1272. [PMID: 31398994 DOI: 10.1177/1535370219868960] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cardiomyocytes are large (∼40,000 µm3), rod-shaped muscle cells that provide the working force behind each heartbeat. These highly structured cells are packed with dense cytoskeletal networks that can be divided into two groups—the contractile (i.e. sarcomeric) cytoskeleton that consists of filamentous actin-myosin arrays organized into myofibrils, and the non-sarcomeric cytoskeleton, which is composed of β- and γ-actin, microtubules, and intermediate filaments. Together, microtubules and intermediate filaments form a cross-linked scaffold, and these networks are responsible for the delivery of intracellular cargo, the transmission of mechanical signals, the shaping of membrane systems, and the organization of myofibrils and organelles. Microtubules are extensively altered as part of both adaptive and pathological cardiac remodeling, which has diverse ramifications for the structure and function of the cardiomyocyte. In heart failure, the proliferation and post-translational modification of the microtubule network is linked to a number of maladaptive processes, including the mechanical impediment of cardiomyocyte contraction and relaxation. This raises the possibility that reversing microtubule alterations could improve cardiac performance, yet therapeutic efforts will strongly benefit from a deeper understanding of basic microtubule biology in the heart. The aim of this review is to summarize the known physiological roles of the cardiomyocyte microtubule network, the consequences of its pathological remodeling, and to highlight the open and intriguing questions regarding cardiac microtubules. Impact statement Advancements in cell biological and biophysical approaches and super-resolution imaging have greatly broadened our view of tubulin biology over the last decade. In the heart, microtubules and microtubule-based transport help to organize and maintain key structures within the cardiomyocyte, including the sarcomere, intercalated disc, protein clearance machinery and transverse-tubule and sarcoplasmic reticulum membranes. It has become increasingly clear that post translational regulation of microtubules is a key determinant of their sub-cellular functionality. Alterations in microtubule network density, stability, and post-translational modifications are hallmarks of pathological cardiac remodeling, and modified microtubules can directly impede cardiomyocyte contractile function in various forms of heart disease. This review summarizes the functional roles and multi-leveled regulation of the cardiac microtubule cytoskeleton and highlights how refined experimental techniques are shedding mechanistic clarity on the regionally specified roles of microtubules in cardiac physiology and pathophysiology.
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Affiliation(s)
- Matthew A Caporizzo
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Christina Yingxian Chen
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.,Penn Cardiovascular Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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54
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Lindsay A, Southern WM, McCourt PM, Larson AA, Hodges JS, Lowe DA, Ervasti JM. Variable cytoplasmic actin expression impacts the sensitivity of different dystrophin-deficient mdx skeletal muscles to eccentric contraction. FEBS J 2019; 286:2562-2576. [PMID: 30942954 PMCID: PMC6613979 DOI: 10.1111/febs.14831] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/24/2019] [Accepted: 04/01/2019] [Indexed: 11/29/2022]
Abstract
Eccentric contractions (ECCs) induce force loss in several skeletal muscles of dystrophin-deficient mice (mdx), with the exception of the soleus (Sol). The eccentric force : isometric force (ECC : ISO), expression level of utrophin, fiber type distribution, and sarcoendoplasmic reticulum calcium ATPase expression are factors that differ between muscles and may contribute to the sensitivity of mdx skeletal muscle to ECC. Here, we confirm that the Sol of mdx mice loses only 13% force compared to 87% in the extensor digitorum longus (EDL) following 10 ECC of isolated muscles. The Sol has a greater proportion of fibers expressing Type I myosin heavy chain (MHC) and expresses 2.3-fold more utrophin compared to the EDL. To examine the effect of ECC : ISO, we show that the mdx Sol is insensitive to ECC at ECC : ISO up to 230 ± 15%. We show that the peroneus longus (PL) muscle presents with similar ECC : ISO compared to the EDL, intermediate force loss (68%) following 10 ECC, and intermediate fiber type distribution and utrophin expression relative to EDL and Sol. The combined absence of utrophin and dystrophin in mdx/utrophin-/- mice rendered the Sol only partially susceptible to ECC and exacerbated force loss in the EDL and PL. Most interestingly, the expression levels of cytoplasmic β- and γ-actins correlate inversely with a given muscle's sensitivity to ECC; EDL < PL < Sol. Our data indicate that fiber type, utrophin, and cytoplasmic actin expression all contribute to the differential sensitivities of mdxEDL, PL, and Sol muscles to ECC.
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Affiliation(s)
- Angus Lindsay
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, USA
| | - William M. Southern
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, USA
| | - Preston M. McCourt
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, USA
| | - Alexie A. Larson
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, USA
| | - James S. Hodges
- Division of Biostatistics, University of Minnesota, Minneapolis, USA
| | - Dawn A. Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, USA
| | - James M. Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, USA
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55
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Randazzo D, Khalique U, Belanto JJ, Kenea A, Talsness DM, Olthoff JT, Tran MD, Zaal KJ, Pak K, Pinal-Fernandez I, Mammen AL, Sackett D, Ervasti JM, Ralston E. Persistent upregulation of the β-tubulin tubb6, linked to muscle regeneration, is a source of microtubule disorganization in dystrophic muscle. Hum Mol Genet 2019; 28:1117-1135. [PMID: 30535187 DOI: 10.1093/hmg/ddy418] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/26/2018] [Accepted: 12/02/2018] [Indexed: 12/20/2022] Open
Abstract
In healthy adult skeletal muscle fibers microtubules form a three-dimensional grid-like network. In the mdx mouse, a model of Duchenne muscular dystrophy (DMD), microtubules are mostly disordered, without periodicity. These microtubule defects have been linked to the mdx mouse pathology. We now report that increased expression of the beta 6 class V β-tubulin (tubb6) contributes to the microtubule changes of mdx muscles. Wild-type muscle fibers overexpressing green fluorescent protein (GFP)-tubb6 (but not GFP-tubb5) have disorganized microtubules whereas mdx muscle fibers depleted of tubb6 (but not of tubb5) normalize their microtubules, suggesting that increasing tubb6 is toxic. However, tubb6 increases spontaneously during differentiation of mouse and human muscle cultures. Furthermore, endogenous tubb6 is not uniformly expressed in mdx muscles but is selectively increased in fiber clusters, which we identify as regenerating. Similarly, mdx-based rescued transgenic mice that retain a higher than expected tubb6 level show focal expression of tubb6 in subsets of fibers. Tubb6 is also upregulated in cardiotoxin-induced mouse muscle regeneration, in human myositis and DMD biopsies, and the tubb6 level correlates with that of embryonic myosin heavy chain, a regeneration marker. In conclusion, modulation of a β-tubulin isotype plays a role in muscle differentiation and regeneration. Increased tubb6 expression and microtubule reorganization are not pathological per se but reflect a return to an earlier developmental stage. However, chronic elevation of tubb6, as occurs in the mdx mouse, may contribute to the repeated cycles of regeneration and to the pathology of the disease.
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Affiliation(s)
- Davide Randazzo
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Umara Khalique
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Joseph J Belanto
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Aster Kenea
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Dana M Talsness
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - John T Olthoff
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Michelle D Tran
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Kristien J Zaal
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Katherine Pak
- Laboratory of Muscle Stem Cells and Gene Regulation, Muscle Disease Unit, NIAMS, NIH, Bethesda, MD, USA
| | - Iago Pinal-Fernandez
- Laboratory of Muscle Stem Cells and Gene Regulation, Muscle Disease Unit, NIAMS, NIH, Bethesda, MD, USA.,Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Andrew L Mammen
- Laboratory of Muscle Stem Cells and Gene Regulation, Muscle Disease Unit, NIAMS, NIH, Bethesda, MD, USA.,Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Dan Sackett
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), NIH, Bethesda, MD, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Evelyn Ralston
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
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56
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Guiraud S, Edwards B, Squire SE, Moir L, Berg A, Babbs A, Ramadan N, Wood MJ, Davies KE. Embryonic myosin is a regeneration marker to monitor utrophin-based therapies for DMD. Hum Mol Genet 2019; 28:307-319. [PMID: 30304405 PMCID: PMC6322073 DOI: 10.1093/hmg/ddy353] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 09/28/2018] [Indexed: 11/13/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal, X-linked muscle-wasting disease caused by lack of the cytoskeletal protein dystrophin. Constitutive utrophin expression, a structural and functional paralogue of dystrophin, can successfully prevent the dystrophic pathology in the dystrophin-deficient mdx mouse model. In dystrophic muscles, utrophin is increased as part of the repair process and localized at the sarcolemma of regenerating myofibers. The presence of developmental myosin such as embryonic myosin (MyHC-emb) and neonatal represents a useful marker of muscle regeneration and a meaningful indicator of muscle damage, which correlates with the clinical severity of milder Becker muscular dystrophy and DMD patients. In the present study, we demonstrate that MyHC-emb is a robust marker of regeneration at different ages and in different skeletal muscles. We also evaluate the correlation between utrophin, dystrophin and MyHC-emb in wild-type (wt) and regenerating dystrophic muscles. Restoration of dystrophin significantly reduced MyHC-emb levels. Similarly, overexpression of utrophin in the transgenic mdx-Fiona mice reduced the number of MyHC-emb positive fibers to wt level, prevented the regenerative process and rescued the muscle function. In contrast, the absence of utrophin in the dystrophin-deficient double-knockout mice resulted in a higher MyHC-emb content and in a more severe dystrophic pathophysiology than in mdx mice. These data illustrate the importance of monitoring utrophin and MyHC-emb levels in the preclinical evaluation of therapies and provide translational support for the use of developmental myosin as a disease biomarker in DMD clinical trials.
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Affiliation(s)
- Simon Guiraud
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Benjamin Edwards
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Sarah E Squire
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Lee Moir
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Adam Berg
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Arran Babbs
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Nesrine Ramadan
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Matthew J Wood
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Kay E Davies
- Department of Physiology, Anatomy and Genetics, MDUK Oxford Neuromuscular Centre, University of Oxford, Oxford OX1 3PT, United Kingdom
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57
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Lindsay A, Schmiechen A, Chamberlain CM, Ervasti JM, Lowe DA. Neopterin/7,8-dihydroneopterin is elevated in Duchenne muscular dystrophy patients and protects mdx skeletal muscle function. Exp Physiol 2019; 103:995-1009. [PMID: 29791760 DOI: 10.1113/ep087031] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 04/30/2018] [Indexed: 01/04/2023]
Abstract
NEW FINDINGS What is the central question of this study? We examined whether the macrophage-synthesized antioxidant 7,8-dihydroneopterin was elevated in Duchenne muscular dystrophy (DMD) patients. We then examined whether 7,8-dihydroneopterin could protect dystrophic skeletal mouse muscle from eccentric contraction-induced force loss and improve recovery. What is the main finding and its importance? Urinary neopterin/creatinine and 7,8-dihydroneopterin/creatinine were elevated in DMD patients. 7,8-Dihydroneopterin attenuated eccentric contraction-induced force loss of dystrophic skeletal mouse muscle and accelerated recovery of force. These results suggest that eccentric contraction-induced force loss is mediated, in part, by an oxidative component and provides a potential protective role for 7,8-dihydroneopterin in DMD. ABSTRACT Macrophage infiltration is a hallmark of dystrophin-deficient muscle. We tested the hypothesis that Duchenne muscular dystrophy (DMD) patients would have elevated levels of the macrophage-synthesized pterins, neopterin and 7,8-dihydroneopterin, compared with unaffected age-matched control subjects. Urinary neopterin/creatinine and 7,8-dihydroneopterin/creatinine were elevated in DMD patients, and 7,8-dihydroneopterin/creatinine was associated with patient age and ambulation. Urinary 7,8-dihydroneopterin corrected for specific gravity was also elevated in DMD patients. Given that 7,8-dihydroneopterin is an antioxidant, we then identified a potential role for 7,8-dihydroneopterin in disease pathology. We assessed whether 7,8-dihydroneopterin could: (i) protect against isometric force loss in wild-type skeletal muscle exposed to various pro-oxidants; and (ii) protect wild-type and mdx muscle from eccentric contraction-induced force loss, which has an oxidative component. Force loss was elicited in isolated extensor digitorum longus (EDL) muscles by 10 eccentric contractions, and recovery of force after the contractions was measured in the presence of exogenous 7,8-dihydroneopterin. 7,8-Dihydroneopterin attenuated isometric force loss by wild-type EDL muscles when challenged by H2 O2 and HOCl, but exacerbated force loss when challenged by SIN-1 (NO• , O2• , ONOO- ). 7,8-Dihydroneopterin attenuated eccentric contraction-induced force loss in mdx muscle. Isometric force production by EDL muscles of mdx mice also recovered to a greater degree after eccentric contractions in the presence of 7,8-dihydroneopterin. The results corroborate macrophage activation in DMD patients, provide a potential protective role for 7,8-dihydroneopterin in the susceptibility of dystrophic muscle to eccentric contractions and indicate that oxidative stress contributes to eccentric contraction-induced force loss in mdx skeletal muscle.
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Affiliation(s)
- Angus Lindsay
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA.,Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Alexandra Schmiechen
- Lillehei Heart Institute, Cancer and Cardiovascular Research Center, University of Minnesota, Minneapolis, MN, USA
| | - Christopher M Chamberlain
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Dawn A Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
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58
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Grimes KM, Prasad V, McNamara JW. Supporting the heart: Functions of the cardiomyocyte's non-sarcomeric cytoskeleton. J Mol Cell Cardiol 2019; 131:187-196. [PMID: 30978342 DOI: 10.1016/j.yjmcc.2019.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 04/02/2019] [Accepted: 04/05/2019] [Indexed: 02/06/2023]
Abstract
The non-contractile cytoskeleton in cardiomyocytes is comprised of cytoplasmic actin, microtubules, and intermediate filaments. In addition to providing mechanical support to these cells, these structures are important effectors of tension-sensing and signal transduction and also provide networks for the transport of proteins and organelles. The majority of our knowledge on the function and structure of these cytoskeletal networks comes from research on proliferative cell types. However, in recent years, researchers have begun to show that there are important cardiomyocyte-specific functions of the cytoskeleton. Here we will discuss the current state of cytoskeletal biology in cardiomyocytes, as well as research from other cell types, that together suggest there is a wealth of knowledge on cardiac health and disease waiting to be uncovered through exploration of the complex signaling networks of cardiomyocyte non-sarcomeric cytoskeletal proteins.
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Affiliation(s)
- Kelly M Grimes
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
| | - Vikram Prasad
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - James W McNamara
- Heart, Lung and Vascular Institute, University of Cincinnati, Cincinnati, OH, USA
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59
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Lindsay A, Chamberlain CM, Witthuhn BA, Lowe DA, Ervasti JM. Dystrophinopathy-associated dysfunction of Krebs cycle metabolism. Hum Mol Genet 2019; 28:942-951. [PMID: 30476171 PMCID: PMC6400043 DOI: 10.1093/hmg/ddy404] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/23/2018] [Accepted: 11/13/2018] [Indexed: 01/03/2023] Open
Abstract
Duchenne muscular dystrophy is a deadly muscle-wasting disorder caused by loss of dystrophin protein. Studies suggest that metabolic alterations are important to disease pathogenesis. Because muscle accounts for ~40% of body mass, we hypothesized that dystrophy-mediated metabolic changes would be measurable in biofluids and that a metabolomic analysis of urine would provide insight into the metabolic status of dystrophic muscle. Using the mdx mouse model, we performed a large-scale metabolomic screen at 1 and 3 months. While 10% of metabolites were altered at age 1 month, 40% were changed at 3 months. Principal component analysis distinguished wild-type from mdx animals, with the greatest separation at 3 months. A critical distinguishing pathway was Krebs cycle metabolite depletion in mdx urine. Five of seven detected Krebs cycle metabolites were depleted in mdx urine, with succinate being the most robustly affected metabolite. Using selected reaction monitoring mass spectrometry, we demonstrated that muscle-specific dystrophin expression corrects mdx succinate depletion. When subjected to downhill treadmill running, wild-type and mdx mice expressing recombinant dystrophin in skeletal muscle displayed significant increases in urinary succinate levels. However, mdx succinate levels were unchanged, suggesting urinary succinate depletion may reflect an inability to upregulate the Krebs cycle following exercise. Finally, we show that supplementing the Krebs cycle in an ex vivo fatigue/recovery assay significantly impacts mdx muscle performance but has no effect on wild-type muscle. Our results suggest that global metabolic impairment is associated with mdx disease progression and that Krebs cycle deficiencies are a downstream consequence of dystrophin loss.
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MESH Headings
- Animals
- Biomarkers
- Citric Acid Cycle
- Disease Models, Animal
- Dystrophin/genetics
- Dystrophin/metabolism
- Energy Metabolism
- Male
- Metabolome
- Metabolomics/methods
- Mice
- Mice, Inbred mdx
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/physiopathology
- Mutation
- Physical Conditioning, Animal
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Affiliation(s)
- Angus Lindsay
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Christopher M Chamberlain
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Bruce A Witthuhn
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Dawn A Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
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60
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Nelson DM, Lindsay A, Judge LM, Duan D, Chamberlain JS, Lowe DA, Ervasti JM. Variable rescue of microtubule and physiological phenotypes in mdx muscle expressing different miniaturized dystrophins. Hum Mol Genet 2019; 27:2090-2100. [PMID: 29618008 DOI: 10.1093/hmg/ddy113] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 03/26/2018] [Indexed: 01/08/2023] Open
Abstract
Delivery of miniaturized dystrophin genes via adeno-associated viral vectors is one leading approach in development to treat Duchenne muscular dystrophy. Here we directly compared the functionality of five mini- and micro-dystrophins via skeletal muscle-specific transgenic expression in dystrophin-deficient mdx mice. We evaluated their ability to rescue defects in the microtubule network, passive stiffness and contractility of skeletal muscle. Transgenic mdx mice expressing the short dystrophin isoform Dp116 served as a negative control. All mini- and micro-dystrophins restored elevated detyrosinated α-tubulin and microtubule density of mdx muscle to values not different from C57BL/10, however, only mini-dystrophins restored the transverse component of the microtubule lattice back to C57BL/10. Passive stiffness values in mdx muscles expressing mini- or micro-dystrophins were not different from C57BL/10. While all mini- and micro-dystrophins conferred significant protection from eccentric contraction-induced force loss in vivo and ex vivo compared to mdx, removal of repeats two and three resulted in less protection from force drop caused by eccentric contraction ex vivo. Our data reveal subtle yet significant differences in the relative functionalities for different therapeutic constructs of miniaturized dystrophin in terms of protection from ex vivo eccentric contraction-induced force loss and restoration of an organized microtubule lattice.
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Affiliation(s)
- D'anna M Nelson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Angus Lindsay
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.,Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - Luke M Judge
- Department of Neurology, University of Washington, Seattle, WA 98195, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, MO 65212, USA
| | | | - Dawn A Lowe
- Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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61
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Ramos JN, Hollinger K, Bengtsson NE, Allen JM, Hauschka SD, Chamberlain JS. Development of Novel Micro-dystrophins with Enhanced Functionality. Mol Ther 2019; 27:623-635. [PMID: 30718090 PMCID: PMC6403485 DOI: 10.1016/j.ymthe.2019.01.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/03/2019] [Accepted: 01/07/2019] [Indexed: 01/24/2023] Open
Abstract
Gene therapies using adeno-associated viral (AAV) vectors have advanced into clinical trials for several diseases, including Duchenne muscular dystrophy (DMD). A limitation of AAV is the carrying capacity (∼5 kb) available for genes and regulatory cassettes (RCs). These size constraints are problematic for the 2.2-Mb dystrophin gene. We previously designed a variety of miniaturized micro-dystrophins (μDys) that displayed significant, albeit incomplete, function in striated muscles. To develop μDys proteins with improved performance, we explored structural modifications of the dystrophin central rod domain. Eight μDys variants were studied that carried unique combinations of between four and six of the 24 spectrin-like repeats present in the full-length protein, as well as various hinge domains. Expression of μDys was regulated by a strong but compact muscle-restricted RC (CK8e) or by the ubiquitously active cytomegalovirus (CMV) RC. Vectors were evaluated by intramuscular injection and systemic delivery to dystrophic mdx4cv mice, followed by analysis of skeletal muscle pathophysiology. Two μDys designs were identified that led to increased force generation compared with previous μDys while also localizing neuronal nitric oxide synthase to the sarcolemma. An AAV vector expressing the smaller of these (μDys5) from the CK8e RC is currently being evaluated in a DMD clinical trial.
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Affiliation(s)
- Julian N Ramos
- Molecular and Cellular Biology Program, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA
| | - Katrin Hollinger
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA
| | - Niclas E Bengtsson
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA
| | - James M Allen
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA
| | - Stephen D Hauschka
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Jeffrey S Chamberlain
- Molecular and Cellular Biology Program, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA; Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA; Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.
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62
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McCourt JL, Talsness DM, Lindsay A, Arpke RW, Chatterton PD, Nelson DM, Chamberlain CM, Olthoff JT, Belanto JJ, McCourt PM, Kyba M, Lowe DA, Ervasti JM. Mouse models of two missense mutations in actin-binding domain 1 of dystrophin associated with Duchenne or Becker muscular dystrophy. Hum Mol Genet 2019; 27:451-462. [PMID: 29194514 DOI: 10.1093/hmg/ddx414] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 11/17/2017] [Indexed: 01/03/2023] Open
Abstract
Missense mutations in the dystrophin protein can cause Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD) through an undefined pathomechanism. In vitro studies suggest that missense mutations in the N-terminal actin-binding domain (ABD1) cause protein instability, and cultured myoblast studies reveal decreased expression levels that can be restored to wild-type with proteasome inhibitors. To further elucidate the pathophysiology of missense dystrophin in vivo, we generated two transgenic mdx mouse lines expressing L54R or L172H mutant dystrophin, which correspond to missense mutations identified in human patients with DMD or BMD, respectively. Our biochemical, histologic and physiologic analysis of the L54R and L172H mice show decreased levels of dystrophin which are proportional to the phenotypic severity. Proteasome inhibitors were ineffective in both the L54R and L172H mice, yet mice homozygous for the L172H transgene were able to express even higher levels of dystrophin which caused further improvements in muscle histology and physiology. Given that missense dystrophin is likely being degraded by the proteasome but whole body proteasome inhibition was not possible, we screened for ubiquitin-conjugating enzymes involved in targeting dystrophin to the proteasome. A myoblast cell line expressing L54R mutant dystrophin was screened with an siRNA library targeting E1, E2 and E3 ligases which identified Amn1, FBXO33, Zfand5 and Trim75. Our study establishes new mouse models of dystrophinopathy and identifies candidate E3 ligases that may specifically regulate dystrophin protein turnover in vivo.
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Affiliation(s)
| | - Dana M Talsness
- Department of Biochemistry, Molecular Biology and Biophysics
| | | | - Robert W Arpke
- Department of Pediatrics University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | | | - D'anna M Nelson
- Department of Biochemistry, Molecular Biology and Biophysics
| | | | - John T Olthoff
- Department of Biochemistry, Molecular Biology and Biophysics
| | | | | | - Michael Kyba
- Department of Pediatrics University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Dawn A Lowe
- Department of Physical Medicine and Rehabilitation
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics
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63
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Abstract
Dystrophin is the largest protein isoform (427 kDa) expressed from the gene defective in Duchenne muscular dystrophy, a lethal muscle-wasting and genetically inherited disease. Dystrophin, localized within a cytoplasmic lattice termed costameres, connects the intracellular cytoskeleton of a myofiber through the cell membrane (sarcolemma) to the surrounding extracellular matrix. In spite of its mechanical regulation roles in stabilizing the sarcolemma during muscle contraction, the underlying molecular mechanism is still elusive. Here, we systematically investigated the mechanical stability and kinetics of the force-bearing central domain of human dystrophin that contains 24 spectrin repeats using magnetic tweezers. We show that the stochastic unfolding and refolding of central domain of dystrophin is able to keep the forces below 25 pN over a significant length change up to ∼800 nm in physiological level of pulling speeds. These results suggest that dystrophin may serve as a molecular shock absorber that defines the physiological level of force in the dystrophin-mediated force-transmission pathway during muscle contraction/stretch, thereby stabilizing the sarcolemma.
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Affiliation(s)
- Shimin Le
- Department of Physics, National University of Singapore, Singapore, 117551
| | - Miao Yu
- Mechanobiology Institute, National University of Singapore, Singapore, 117411
| | - Ladislav Hovan
- Mechanobiology Institute, National University of Singapore, Singapore, 117411
| | - Zhihai Zhao
- Department of Physics, National University of Singapore, Singapore, 117551
| | - James Ervasti
- College of Biological Sciences, University of Minnesota, MN, USA, 55455
| | - Jie Yan
- Department of Physics, National University of Singapore, Singapore, 117551
- Mechanobiology Institute, National University of Singapore, Singapore, 117411
- Centre for BioImaging Sciences, National University of Singapore, Singapore, 117546
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64
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Lindsay A, Larson AA, Verma M, Ervasti JM, Lowe DA. Isometric resistance training increases strength and alters histopathology of dystrophin-deficient mouse skeletal muscle. J Appl Physiol (1985) 2018; 126:363-375. [PMID: 30571283 DOI: 10.1152/japplphysiol.00948.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mutation to the dystrophin gene causes skeletal muscle weakness in patients with Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD). Deliberation continues regarding implications of prescribing exercise for these patients. The purpose of this study was to determine whether isometric resistance exercise (~10 tetanic contractions/session) improves skeletal muscle strength and histopathology in the mdx mouse model of DMD. Three isometric training sessions increased in vivo isometric torque (22%) and contractility rates (54%) of anterior crural muscles of mdx mice. Mice expressing a BMD-causing missense mutated dystrophin on the mdx background showed comparable increases in torque (22%), while wild-type mice showed less change (11%). Increases in muscle function occurred within 1 h and peaked 3 days posttraining; however, the adaptation was lost after 7 days unless retrained. Six isometric training sessions over 4 wk caused increased isometric torque (28%) and contractility rates (22-28%), reduced fibrosis, as well as greater uniformity of fiber cross-sectional areas, fewer embryonic myosin heavy-chain-positive fibers, and more satellite cells in tibialis anterior muscle compared with the contralateral untrained muscle. Ex vivo functional analysis of isolated extensor digitorum longus (EDL) muscle from the trained hindlimb revealed greater absolute isometric force, lower passive stiffness, and a lower susceptibility to eccentric contraction-induced force loss compared with untrained EDL muscle. Overall, these data support the concept that exercise training in the form of isometric tetanic contractions can improve contractile function of dystrophin-deficient muscle, indicating a potential role for enhancing muscle strength in patients with DMD and BMD. NEW & NOTEWORTHY We focused on adaptive responses of dystrophin-deficient mouse skeletal muscle to isometric contraction training and report that in the absence of dystrophin (or in the presence of a mutated dystrophin), strength and muscle histopathology are improved. Results suggest that the strength gains are associated with fiber hypertrophy, reduced fibrosis, increased number of satellite cells, and blunted eccentric contraction-induced force loss in vitro. Importantly, there was no indication that the isometric exercise training was deleterious to dystrophin-deficient muscle.
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Affiliation(s)
- Angus Lindsay
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota , Minneapolis, Minnesota.,Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota , Minneapolis, Minnesota
| | - Alexie A Larson
- Department of Integrative Biology and Physiology, University of Minnesota , Minneapolis, Minnesota
| | - Mayank Verma
- Department of Integrative Biology and Physiology, University of Minnesota , Minneapolis, Minnesota.,Medical Scientist Training Program, University of Minnesota Medical School , Minneapolis, Minnesota
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota , Minneapolis, Minnesota
| | - Dawn A Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota , Minneapolis, Minnesota
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65
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Lindsay A, McCourt PM, Karachunski P, Lowe DA, Ervasti JM. Xanthine oxidase is hyper-active in Duchenne muscular dystrophy. Free Radic Biol Med 2018; 129:364-371. [PMID: 30312761 PMCID: PMC6599518 DOI: 10.1016/j.freeradbiomed.2018.10.404] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/21/2018] [Accepted: 10/04/2018] [Indexed: 11/30/2022]
Abstract
Generation of superoxide by xanthine oxidase can be stimulated under ischemic and aberrant calcium homeostasis. Because patients and mice with Duchenne muscular dystrophy (DMD) suffer from ischemia and excessive calcium influx, we tested the hypothesis that xanthine oxidase activity is elevated and contributes to disease pathology. Xanthine oxidase activity was measured by urinary isoxanthopterin in DMD patients at rest and in response to exercise. Urinary isoxanthopterin/creatinine was elevated compared to age-matched controls and Becker muscular dystrophy (BMD) patients. Concentrations were also increased after a six minute walk test in ambulatory patients. We also measured urinary isoxanthopterin in wildtype mice and a number of dystrophic mouse models; the DMD mouse model (mdx), mdx mice overexpressing a variety of transgenic miniaturized and chimeric skeletal muscle-specific dystrophins and utrophin and the β-sarcoglycan deficient (Scgb-/-) mouse which represents type 2E human limb-girdle muscular dystrophy. Mdx and Scgb-/-mice had greater urinary isoxanthopterin/creatinine than wildtype mice while mdx mice expressing dystrophin or utrophin linking the extracellular matrix to the actin cytoskeleton were not different than wildtype. We also measured higher levels of urinary ortho-tyrosine in humans and mice deficient for dystrophin to confirm elevated oxidative stress. Surprisingly, mdx had lower xanthine oxidase protein levels and higher mRNA in gastrocnemius muscle compared to wildtype mice, however, the enzymatic activity of skeletal muscle xanthine oxidase was elevated above wildtype and a transgenic rescued mdx mouse (DysΔMTB-mdx). Downhill treadmill running also caused significant increases in mdx urinary isoxanthopterin that was prevented with the xanthine oxidase inhibitor allopurinol. Similarly, in vitro eccentric contraction-induced force drop of mdx muscle was attenuated by the allopurinol metabolite, oxypurinol. Together, our data suggests hyper-activity of xanthine oxidase in DMD, identifies xanthine oxidase activity as a contributing factor in eccentric contraction-induced force drop of dystrophin-deficient skeletal muscle and highlights the potential of isoxanthopterin as a noninvasive biomarker in DMD.
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MESH Headings
- Adolescent
- Allopurinol/pharmacology
- Animals
- Biomarkers/urine
- Case-Control Studies
- Creatinine/urine
- Dystrophin/deficiency
- Dystrophin/genetics
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation
- Humans
- Male
- Mice
- Mice, Inbred mdx
- Muscle Contraction/drug effects
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/physiopathology
- Muscular Dystrophy, Animal/drug therapy
- Muscular Dystrophy, Animal/enzymology
- Muscular Dystrophy, Animal/genetics
- Muscular Dystrophy, Animal/physiopathology
- Muscular Dystrophy, Duchenne/drug therapy
- Muscular Dystrophy, Duchenne/enzymology
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/physiopathology
- Oxypurinol/pharmacology
- Sarcoglycans/deficiency
- Sarcoglycans/genetics
- Tyrosine/urine
- Utrophin/deficiency
- Utrophin/genetics
- Xanthine Oxidase/genetics
- Xanthine Oxidase/urine
- Xanthopterin/urine
- Young Adult
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Affiliation(s)
- Angus Lindsay
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, USA; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, USA.
| | - Preston M McCourt
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, USA
| | - Peter Karachunski
- Department of Pediatrics, University of Minnesota, Minneapolis, USA; Department of Neurology, University of Minnesota, Minneapolis, USA
| | - Dawn A Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, USA
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Ramalho TC, de Castro AA, Tavares TS, Silva MC, Silva DR, Cesar PH, Santos LA, da Cunha EFF, Nepovimova E, Kuca K. Insights into the pharmaceuticals and mechanisms of neurological orphan diseases: Current Status and future expectations. Prog Neurobiol 2018; 169:135-157. [PMID: 29981392 DOI: 10.1016/j.pneurobio.2018.06.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 06/30/2018] [Indexed: 12/20/2022]
Abstract
Several rare or orphan diseases have been characterized that singly affect low numbers of people, but cumulatively reach ∼6%-10% of the population in Europe and in the United States. Human genetics has shown to be broadly effective when evaluating subjacent genetic defects such as orphan genetic diseases, but on the other hand, a modest progress has been achieved toward comprehending the molecular pathologies and designing new therapies. Chemical genetics, placed at the interface of chemistry and genetics, could be employed to understand the molecular mechanisms of subjacent illnesses and for the discovery of new remediation processes. This review debates current progress in chemical genetics, and how a variety of compounds and reaction mechanisms can be used to study and ultimately treat rare genetic diseases. We focus here on a study involving Amyotrophic lateral sclerosis (ALS), Duchenne Muscular Dystrophy (DMD), Spinal muscular atrophy (SMA) and Familial Amyloid Polyneuropathy (FAP), approaching different treatment methods and the reaction mechanisms of several compounds, trying to elucidate new routes capable of assisting in the treatment profile.
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Affiliation(s)
- Teodorico C Ramalho
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, Brazil; Center for Basic and Applied Research, Faculty of Informatics and Management, University of Hradec Kralove, Hradec Kralove, Czech Republic.
| | | | - Tássia S Tavares
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, Brazil
| | - Maria C Silva
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, Brazil
| | - Daniela R Silva
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, Brazil
| | - Pedro H Cesar
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, Brazil
| | - Lucas A Santos
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, Brazil
| | - Elaine F F da Cunha
- Department of Chemistry, Federal University of Lavras, 37200-000, Lavras, Brazil
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.
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67
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Abstract
PURPOSE OF REVIEW To construct a framework to understand the different molecular interventions for muscular dystrophy. RECENT FINDINGS The recent approval of antisense oligonucleotides treatment for Duchenne muscular dystrophy and spinal muscular atrophy and current clinical trials using recombinant adeno-associated virus for the treatment of those diseases suggests that we are at a tipping point where we are able to treat and potentially cure muscular dystrophies. Understanding the basic molecular pathogenesis of muscular dystrophies and the molecular biology of the treatment allows for critical evaluation of the proposed therapies.
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Affiliation(s)
- Ava Y Lin
- Department of Neurology, University of Washington, Box 356465, 1959 NE Pacific Street, Seattle, WA, 98195-6465, USA
| | - Leo H Wang
- Department of Neurology, University of Washington, Box 356465, 1959 NE Pacific Street, Seattle, WA, 98195-6465, USA.
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68
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Delalande O, Molza AE, Dos Santos Morais R, Chéron A, Pollet É, Raguenes-Nicol C, Tascon C, Giudice E, Guilbaud M, Nicolas A, Bondon A, Leturcq F, Férey N, Baaden M, Perez J, Roblin P, Piétri-Rouxel F, Hubert JF, Czjzek M, Le Rumeur E. Dystrophin's central domain forms a complex filament that becomes disorganized by in-frame deletions. J Biol Chem 2018. [PMID: 29535188 DOI: 10.1074/jbc.m117.809798] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Dystrophin, encoded by the DMD gene, is critical for maintaining plasma membrane integrity during muscle contraction events. Mutations in the DMD gene disrupting the reading frame prevent dystrophin production and result in severe Duchenne muscular dystrophy (DMD); in-frame internal deletions allow production of partly functional internally deleted dystrophin and result in less severe Becker muscular dystrophy (BMD). Many known BMD deletions occur in dystrophin's central domain, generally considered to be a monotonous rod-shaped domain based on the knowledge of spectrin family proteins. However, the effects caused by these deletions, ranging from asymptomatic to severe BMD, argue against the central domain serving only as a featureless scaffold. We undertook structural studies combining small-angle X-ray scattering and molecular modeling in an effort to uncover the structure of the central domain, as dystrophin has been refractory to characterization. We show that this domain appears to be a tortuous and complex filament that is profoundly disorganized by the most severe BMD deletion (loss of exons 45-47). Despite the preservation of large parts of the binding site for neuronal nitric oxide synthase (nNOS) in this deletion, computational approaches failed to recreate the association of dystrophin with nNOS. This observation is in agreement with a strong decrease of nNOS immunolocalization in muscle biopsies, a parameter related to the severity of BMD phenotypes. The structural description of the whole dystrophin central domain we present here is a first necessary step to improve the design of microdystrophin constructs toward the goal of a successful gene therapy for DMD.
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Affiliation(s)
- Olivier Delalande
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France,
| | - Anne-Elisabeth Molza
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
| | - Raphael Dos Santos Morais
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France.,the Synchrotron SOLEIL, 91190 Saint Aubin, France.,the Laboratoire Léon-Brillouin, UMR 12 CEA-CNRS, Université Paris-Saclay, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Angélique Chéron
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
| | - Émeline Pollet
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
| | - Céline Raguenes-Nicol
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
| | - Christophe Tascon
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
| | - Emmanuel Giudice
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
| | - Marine Guilbaud
- the Sorbonne Universités UPMC-INSERM-UMRS 97-CNRS FRE 3617, Institut de Myologie, 75013 Paris, France
| | - Aurélie Nicolas
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
| | - Arnaud Bondon
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France.,the Université Rennes, CNRS, Institut des Sciences Chimiques de Rennes-UMR 6226, PRISM, 35000 Rennes, France
| | - France Leturcq
- the Sorbonne Universités UPMC-INSERM-UMRS 97-CNRS FRE 3617, Institut de Myologie, 75013 Paris, France.,the AP-HP, Groupe Hospitalier Cochin-Broca-Hôtel Dieu, Laboratoire de Biochimie et Génétique Moléculaire, 75014 Paris, France
| | - Nicolas Férey
- the CNRS UPR3251, Université Paris XI, 91403 Orsay Cedex, France
| | - Marc Baaden
- the CNRS UPR9080, Université Paris Diderot, Sorbonne Paris Cité, 75005 Paris, France
| | - Javier Perez
- the Synchrotron SOLEIL, 91190 Saint Aubin, France
| | - Pierre Roblin
- the Synchrotron SOLEIL, 91190 Saint Aubin, France.,the INRA-Biopolymères, Interaction et Assemblages, 44000 Nantes, France
| | - France Piétri-Rouxel
- the Sorbonne Universités UPMC-INSERM-UMRS 97-CNRS FRE 3617, Institut de Myologie, 75013 Paris, France
| | - Jean-François Hubert
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
| | - Mirjam Czjzek
- the Sorbonne Universités, UPMC Université Paris 06, 75006 Paris, France, and.,the CNRS UMR 8227, Integrative Biology of Marine Models, 29688 Roscoff Cedex, France
| | - Elisabeth Le Rumeur
- From the Université de Rennes, CNRS, Institut de Génétique et Développement de Rennes-UMR 6290, 35000 Rennes, France
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69
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Guiraud S, Roblin D, Kay DE. The potential of utrophin modulators for the treatment of Duchenne muscular dystrophy. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2018.1438261] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Simon Guiraud
- Oxford Neuromuscular Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | | | - Davies. E. Kay
- Oxford Neuromuscular Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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70
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Belanto JJ, Olthoff JT, Mader TL, Chamberlain CM, Nelson DM, McCourt PM, Talsness DM, Gundersen GG, Lowe DA, Ervasti JM. Independent variability of microtubule perturbations associated with dystrophinopathy. Hum Mol Genet 2018; 25:4951-4961. [PMID: 28171583 DOI: 10.1093/hmg/ddw318] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/15/2016] [Accepted: 09/12/2016] [Indexed: 11/14/2022] Open
Abstract
Absence of the protein dystrophin causes Duchenne muscular dystrophy. Dystrophin directly binds to microtubules in vitro, and its absence in vivo correlates with disorganization of the subsarcolemmal microtubule lattice, increased detyrosination of α-tubulin, and altered redox signaling. We previously demonstrated that the dystrophin homologue utrophin neither binds microtubules in vitro nor rescues microtubule lattice organization when overexpressed in muscles of dystrophin-deficient mdx mice. Here, we fine-mapped the dystrophin domain necessary for microtubule binding to spectrin-like repeats 20–22. We show that transgenic mdx mice expressing a full-length dystrophin/utrophin chimera completely lacking microtubule binding activity are surprisingly rescued for all measured dystrophic phenotypes, including full restoration of microtubule lattice organization. Conversely, despite the presence of dystrophin at the sarcolemma, β-sarcoglycan-deficient skeletal muscle presents with a disorganized and densified microtubule lattice. Finally, we show that the levels of α-tubulin detyrosination remain significantly elevated to that of mdx levels in transgenic mdx mice expressing nearly full-length dystrophin. Our results demonstrate that the microtubule-associated perturbations of mdx muscle are distinct, separable, and can vary independently from other parameters previously ascribed to dystrophin deficiency.
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Affiliation(s)
- Joseph J Belanto
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - John T Olthoff
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Tara L Mader
- Programs in Rehabilitation Science and Physical Therapy, Department of Physical Medicine and Rehabilitation, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Christopher M Chamberlain
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - D'anna M Nelson
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Preston M McCourt
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Dana M Talsness
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Gregg G Gundersen
- Department of Pathology & Cell Biology, Columbia University, New York, NY, USA
| | - Dawn A Lowe
- Programs in Rehabilitation Science and Physical Therapy, Department of Physical Medicine and Rehabilitation, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology, and Biophysics, and Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
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71
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Loehr JA, Wang S, Cully TR, Pal R, Larina IV, Larin KV, Rodney GG. NADPH oxidase mediates microtubule alterations and diaphragm dysfunction in dystrophic mice. eLife 2018; 7:31732. [PMID: 29381135 PMCID: PMC5812717 DOI: 10.7554/elife.31732] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/20/2018] [Indexed: 12/18/2022] Open
Abstract
Skeletal muscle from mdx mice is characterized by increased Nox2 ROS, altered microtubule network, increased muscle stiffness, and decreased muscle/respiratory function. While microtubule de-tyrosination has been suggested to increase stiffness and Nox2 ROS production in isolated single myofibers, its role in altering tissue stiffness and muscle function has not been established. Because Nox2 ROS production is upregulated prior to microtubule network alterations and ROS affect microtubule formation, we investigated the role of Nox2 ROS in diaphragm tissue microtubule organization, stiffness and muscle/respiratory function. Eliminating Nox2 ROS prevents microtubule disorganization and reduces fibrosis and muscle stiffness in mdx diaphragm. Fibrosis accounts for the majority of variance in diaphragm stiffness and decreased function, implicating altered extracellular matrix and not microtubule de-tyrosination as a modulator of diaphragm tissue function. Ultimately, inhibiting Nox2 ROS production increased force and respiratory function in dystrophic diaphragm, establishing Nox2 as a potential therapeutic target in Duchenne muscular dystrophy.
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Affiliation(s)
- James Anthony Loehr
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Shang Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Tanya R Cully
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Rituraj Pal
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Irina V Larina
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Kirill V Larin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States.,Department of Biomedical Engineering, University of Houston, Houston, United States.,Interdisciplinary Laboratory of Biophotonics, Tomsk State University, Tomsk, Russia
| | - George G Rodney
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
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72
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Gibbs EM, Crosbie-Watson RH. A Simple and Low-cost Assay for Measuring Ambulation in Mouse Models of Muscular Dystrophy. J Vis Exp 2017:56772. [PMID: 29364281 PMCID: PMC5908392 DOI: 10.3791/56772] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Measuring functional outcomes in the treatment of muscular dystrophy is an essential aspect of preclinical testing. The assessment of voluntary ambulation in mouse models is a non-invasive and reproducible activity assay that is directly analogous to measures of patient ambulation such as the 6-minute walk test and related mobility scores. Many common methods for testing mouse ambulation speed and distance are based on the open field test, where an animal's free movement within an arena is measured over time. One major downside to this approach is that commercial software and equipment for high-resolution motion tracking is expensive and may require transferring mice to specialized facilities for testing. Here, we describe a low-cost, video-based system for measuring mouse ambulation that utilizes free and open-source software. Using this protocol, we demonstrate that voluntary ambulation in the dystrophin-null mdx mouse model for Duchenne muscular dystrophy (DMD) is decreased relative to wild-type mouse activity. In mdx mice expressing the utrophin transgene, these activity deficits are not observed and the total distance traveled is indistinguishable from wild-type mice. This method is effective for measuring changes in voluntary ambulation associated with dystrophic pathology, and provides a versatile platform that can be readily adapted to diverse research settings.
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Affiliation(s)
- Elizabeth M Gibbs
- Department of Integrative Biology and Physiology, University of California; Center for Duchenne Muscular Dystrophy, University of California
| | - Rachelle H Crosbie-Watson
- Department of Integrative Biology and Physiology, University of California; Center for Duchenne Muscular Dystrophy, University of California; Department of Neurology, David Geffen School of Medicine, University of California; Molecular Biology Institute, University of California;
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73
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Yurchenco PD, McKee KK, Reinhard JR, Rüegg MA. Laminin-deficient muscular dystrophy: Molecular pathogenesis and structural repair strategies. Matrix Biol 2017; 71-72:174-187. [PMID: 29191403 DOI: 10.1016/j.matbio.2017.11.009] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 12/19/2022]
Abstract
Laminins are large heterotrimers composed of the α, β and γ subunits with distinct tissue-specific and developmentally regulated expression patterns. The laminin-α2 subunit, encoded by the LAMA2 gene, is expressed in skeletal muscle, Schwann cells of the peripheral nerve and astrocytes and pericytes of the capillaries in the brain. Mutations in LAMA2 cause the most common type of congenital muscular dystrophies, called LAMA2 MD or MDC1A. The disorder manifests mostly as a muscular dystrophy but slowing of nerve conduction contributes to the disease. There are severe, non-ambulatory or milder, ambulatory variants, the latter resulting from reduced laminin-α2 expression and/or deficient laminin-α2 function. Lm-211 (α2β1γ1) is responsible for initiating basement membrane assembly. This is primarily accomplished by anchorage of Lm-211 to dystroglycan and α7β1 integrin receptors, polymerization, and binding to nidogen and other structural components. In LAMA2 MD, Lm-411 replaces Lm-211; however, Lm-411 lacks the ability to polymerize and bind to receptors. This results in a weakened basement membrane leading to the disease. The possibility of introducing structural repair proteins that correct the underlying abnormality is an attractive therapeutic goal. Recent studies in mouse models for LAMA2 MD reveal that introduction of laminin-binding linker proteins that restore lost functional activities can substantially ameliorate the disease. This review discusses the underlying mechanism of this repair and compares this approach to other developing therapies employing pharmacological treatments.
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Affiliation(s)
- Peter D Yurchenco
- Dept. Pathology & Laboratory Medicine, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Karen K McKee
- Dept. Pathology & Laboratory Medicine, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | | | - Markus A Rüegg
- Biozentrum, University of Basel, 4056 Basel, Switzerland.
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74
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Wada E, Tanihata J, Iwamura A, Takeda S, Hayashi YK, Matsuda R. Treatment with the anti-IL-6 receptor antibody attenuates muscular dystrophy via promoting skeletal muscle regeneration in dystrophin-/utrophin-deficient mice. Skelet Muscle 2017; 7:23. [PMID: 29078808 PMCID: PMC5660454 DOI: 10.1186/s13395-017-0140-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 10/16/2017] [Indexed: 11/12/2022] Open
Abstract
Background Chronic increases in the levels of the inflammatory cytokine interleukin-6 (IL-6) in serum and skeletal muscle are thought to contribute to the progression of muscular dystrophy. Dystrophin/utrophin double-knockout (dKO) mice develop a more severe and progressive muscular dystrophy than the mdx mice, the most common murine model of Duchenne muscular dystrophy (DMD). In particular, dKO mice have smaller body sizes and muscle diameters, and develop progressive kyphosis and fibrosis in skeletal and cardiac muscles. As mdx mice and DMD patients, we found that IL-6 levels in the skeletal muscle were significantly increased in dKO mice. Thus, in this study, we aimed to analyze the effects of IL-6 receptor (IL-6R) blockade on the muscle pathology of dKO mice. Methods Male dKO mice were administered an initial injection (200 mg/kg intraperitoneally (i.p.)) of either the anti-IL-6R antibody MR16-1 or an isotype-matched control rat IgG at the age of 14 days, and were then given weekly injections (25 mg/kg i.p.) until 90 days of age. Results Treatment of dKO mice with the MR16-1 antibody successfully inhibited the IL-6 pathway in the skeletal muscle and resulted in a significant reduction in the expression levels of phosphorylated signal transducer and activator of transcription 3 in the skeletal muscle. Pathologically, a significant increase in the area of embryonic myosin heavy chain-positive myofibers and muscle diameter, and reduced fibrosis in the quadriceps muscle were observed. These results demonstrated the therapeutic effects of IL-6R blockade on promoting muscle regeneration. Consistently, serum creatine kinase levels were decreased. Despite these improvements observed in the limb muscles, degeneration of the diaphragm and cardiac muscles was not ameliorated by the treatment of mice with the MR16-1 antibody. Conclusion As no adverse effects of treatment with the MR16-1 antibody were observed, our results indicate that the anti-IL-6R antibody is a potential therapy for muscular dystrophy particularly for promoting skeletal muscle regeneration. Electronic supplementary material The online version of this article (10.1186/s13395-017-0140-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eiji Wada
- Department of Pathophysiology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku, Tokyo, Japan. .,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo, Japan.
| | - Jun Tanihata
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, Japan.,Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, Japan
| | - Akira Iwamura
- Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, Japan
| | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, Japan
| | - Yukiko K Hayashi
- Department of Pathophysiology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku, Tokyo, Japan
| | - Ryoichi Matsuda
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo, Japan
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75
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Mishra MK, Loro E, Sengupta K, Wilton SD, Khurana TS. Functional improvement of dystrophic muscle by repression of utrophin: let-7c interaction. PLoS One 2017; 12:e0182676. [PMID: 29045431 PMCID: PMC5646768 DOI: 10.1371/journal.pone.0182676] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 07/21/2017] [Indexed: 02/02/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a fatal genetic disease caused by an absence of the 427kD muscle-specific dystrophin isoform. Utrophin is the autosomal homolog of dystrophin and when overexpressed, can compensate for the absence of dystrophin and rescue the dystrophic phenotype of the mdx mouse model of DMD. Utrophin is subject to miRNA mediated repression by several miRNAs including let-7c. Inhibition of utrophin: let-7c interaction is predicted to 'repress the repression' and increase utrophin expression. We developed and tested the ability of an oligonucleotide, composed of 2'-O-methyl modified bases on a phosphorothioate backbone, to anneal to the utrophin 3'UTR and prevent let-7c miRNA binding, thereby upregulating utrophin expression and improving the dystrophic phenotype in vivo. Suppression of utrophin: let-7c interaction using bi-weekly intraperitoneal injections of let7 site blocking oligonucleotides (SBOs) for 1 month in the mdx mouse model for DMD, led to increased utrophin expression along with improved muscle histology, decreased fibrosis and increased specific force. The functional improvement of dystrophic muscle achieved using let7-SBOs suggests a novel utrophin upregulation-based therapeutic strategy for DMD.
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Affiliation(s)
- Manoj K. Mishra
- Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Emanuele Loro
- Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kasturi Sengupta
- Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Steve D. Wilton
- Perron Institute for Neurological and Translational Science, University of Western Australia, Perth, Australia
- Centre for Comparative Genomics, Murdoch University, Perth, Australia
| | - Tejvir S. Khurana
- Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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76
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Wilson K, Faelan C, Patterson-Kane JC, Rudmann DG, Moore SA, Frank D, Charleston J, Tinsley J, Young GD, Milici AJ. Duchenne and Becker Muscular Dystrophies: A Review of Animal Models, Clinical End Points, and Biomarker Quantification. Toxicol Pathol 2017; 45:961-976. [PMID: 28974147 DOI: 10.1177/0192623317734823] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are neuromuscular disorders that primarily affect boys due to an X-linked mutation in the DMD gene, resulting in reduced to near absence of dystrophin or expression of truncated forms of dystrophin. Some newer therapeutic interventions aim to increase sarcolemmal dystrophin expression, and accurate dystrophin quantification is critical for demonstrating pharmacodynamic relationships in preclinical studies and clinical trials. Current challenges with measuring dystrophin include the variation in protein expression within individual muscle fibers and across whole muscle samples, the presence of preexisting dystrophin-positive revertant fibers, and trace amounts of residual dystrophin. Immunofluorescence quantification of dystrophin can overcome many of these challenges, but manual quantification of protein expression may be complicated by variations in the collection of images, reproducible scoring of fluorescent intensity, and bias introduced by manual scoring of typically only a few high-power fields. This review highlights the pathology of DMD and BMD, discusses animal models of DMD and BMD, and describes dystrophin biomarker quantitation in DMD and BMD, with several image analysis approaches, including a new automated method that evaluates protein expression of individual muscle fibers.
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Affiliation(s)
- Kristin Wilson
- 1 Flagship Biosciences, Inc., Westminster, Colorado, USA
| | - Crystal Faelan
- 1 Flagship Biosciences, Inc., Westminster, Colorado, USA
| | | | | | - Steven A Moore
- 2 Department of Pathology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Diane Frank
- 3 Sarepta Therapeutics, Inc., Cambridge, Massachusetts, USA
| | - Jay Charleston
- 3 Sarepta Therapeutics, Inc., Cambridge, Massachusetts, USA
| | - Jon Tinsley
- 4 Summit Therapeutics, Abingdon, United Kingdom
| | - G David Young
- 1 Flagship Biosciences, Inc., Westminster, Colorado, USA
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77
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Utrophin Compensates dystrophin Loss during Mouse Spermatogenesis. Sci Rep 2017; 7:7372. [PMID: 28785010 PMCID: PMC5547154 DOI: 10.1038/s41598-017-05993-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 06/07/2017] [Indexed: 12/04/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder resulting from mutations in the dystrophin gene. The mdx/utrn−/− mouse, lacking in both dystrophin and its autosomal homologue utrophin, is commonly used to model the clinical symptoms of DMD. Interestingly, these mice are infertile but the mechanisms underlying this phenomenon remain unclear. Using dystrophin deficient mdx mouse and utrophin haplodeficient mdx/utrn+/− mouse models, we demonstrate the contribution of Dp427 (full-length dystrophin) and utrophin to testis and epididymis development, as well as spermatogenesis. We show that Dp427 deficiency disturbed the balance between proliferation and apoptosis of germ cells during spermatogenesis, which was further disrupted with utrophin haplodeficiency, deciphering a compensatory role of utrophin for dystrophin in the male reproductive system. In the spermatozoa, we have found a compensatory response of utrophin to dystrophin deficiency - namely the upregulation and relocation of utrophin to the flagellar midpiece. This study demonstrates the contribution of Dp427 and utrophin in male fertility, suggesting a potential pathology in DMD patients.
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78
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Kodippili K, Hakim CH, Pan X, Yang HT, Yue Y, Zhang Y, Shin JH, Yang NN, Duan D. Dual AAV Gene Therapy for Duchenne Muscular Dystrophy with a 7-kb Mini-Dystrophin Gene in the Canine Model. Hum Gene Ther 2017; 29:299-311. [PMID: 28793798 DOI: 10.1089/hum.2017.095] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Dual adeno-associated virus (AAV) technology was developed in 2000 to double the packaging capacity of the AAV vector. The proof of principle has been demonstrated in various mouse models. Yet, pivotal evidence is lacking in large animal models of human diseases. Here we report expression of a 7-kb canine ΔH2-R15 mini-dystrophin gene using a pair of dual AAV vectors in the canine model of Duchenne muscular dystrophy (DMD). The ΔH2-R15 minigene is by far the most potent synthetic dystrophin gene engineered for DMD gene therapy. We packaged minigene dual vectors in Y731F tyrosine-modified AAV-9 and delivered to the extensor carpi ulnaris muscle of a 12-month-old affected dog at the dose of 2 × 1013 viral genome particles/vector/muscle. Widespread mini-dystrophin expression was observed 2 months after gene transfer. The missing dystrophin-associated glycoprotein complex was restored. Treatment also reduced muscle degeneration and fibrosis and improved myofiber size distribution. Importantly, dual AAV therapy greatly protected the muscle from eccentric contraction-induced force loss. Our data provide the first clear evidence that dual AAV therapy can be translated to a diseased large mammal. Further development of dual AAV technology may lead to effective therapies for DMD and many other diseases in human patients.
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Affiliation(s)
- Kasun Kodippili
- 1 Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri , Columbia, Missouri
| | - Chady H Hakim
- 1 Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri , Columbia, Missouri.,2 National Center for Advancing Translational Sciences , Bethesda, Maryland
| | - Xiufang Pan
- 1 Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri , Columbia, Missouri
| | - Hsiao T Yang
- 1 Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri , Columbia, Missouri.,3 Department of Biomedical Sciences, College of Veterinary Medicine, The University of Missouri , Columbia, Missouri
| | - Yongping Yue
- 1 Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri , Columbia, Missouri
| | - Yadong Zhang
- 1 Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri , Columbia, Missouri
| | - Jin-Hong Shin
- 1 Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri , Columbia, Missouri
| | - N Nora Yang
- 2 National Center for Advancing Translational Sciences , Bethesda, Maryland
| | - Dongsheng Duan
- 1 Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri , Columbia, Missouri.,3 Department of Biomedical Sciences, College of Veterinary Medicine, The University of Missouri , Columbia, Missouri.,4 Department of Neurology, School of Medicine, The University of Missouri , Columbia, Missouri.,5 Department of Bioengineering, The University of Missouri , Columbia, Missouri
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79
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Robison P, Prosser BL. Microtubule mechanics in the working myocyte. J Physiol 2017; 595:3931-3937. [PMID: 28116814 DOI: 10.1113/jp273046] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/05/2016] [Indexed: 11/08/2022] Open
Abstract
The mechanical role of cardiac microtubules (MTs) has been a topic of some controversy. Early studies, which relied largely on pharmacological interventions that altered the MT cytoskeleton as a whole, presented no consistent role. Recent advances in the ability to observe and manipulate specific properties of the cytoskeleton have strengthened our understanding. Direct observation of MTs in working myocytes suggests a spring-like function, one that is surprisingly tunable by post-translational modification (PTM). Specifically, detyrosination of MTs facilitates an interaction with intermediate filaments that complex with the sarcomere, altering myocyte stiffness, contractility, and mechanosignalling. Such results support a paradigm of cytoskeletal regulation based on not only polymerization, but also associations with binding partners and PTMs that divide the MT cytoskeleton into functionally distinct subsets. The evolutionary costs and benefits of tuning cytoskeletal mechanics remain an open question, one that we discuss herein. Nevertheless, mechanically distinct MT subsets provide a rich new source of therapeutic targets for a variety of phenomena in the heart.
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Affiliation(s)
- Patrick Robison
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
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80
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Iyer SR, Shah SB, Valencia AP, Schneider MF, Hernández-Ochoa EO, Stains JP, Blemker SS, Lovering RM. Altered nuclear dynamics in MDX myofibers. J Appl Physiol (1985) 2016; 122:470-481. [PMID: 27979987 DOI: 10.1152/japplphysiol.00857.2016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/02/2016] [Accepted: 12/06/2016] [Indexed: 01/17/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic disorder in which the absence of dystrophin leads to progressive muscle degeneration and weakness. Although the genetic basis is known, the pathophysiology of dystrophic skeletal muscle remains unclear. We examined nuclear movement in wild-type (WT) and muscular dystrophy mouse model for DMD (MDX) (dystrophin-null) mouse myofibers. We also examined expression of proteins in the linkers of nucleoskeleton and cytoskeleton (LINC) complex, as well as nuclear transcriptional activity via histone H3 acetylation and polyadenylate-binding nuclear protein-1. Because movement of nuclei is not only LINC dependent but also microtubule dependent, we analyzed microtubule density and organization in WT and MDX myofibers, including the application of a unique 3D tool to assess microtubule core structure. Nuclei in MDX myofibers were more mobile than in WT myofibers for both distance traveled and velocity. MDX muscle shows reduced expression and labeling intensity of nesprin-1, a LINC protein that attaches the nucleus to the microtubule and actin cytoskeleton. MDX nuclei also showed altered transcriptional activity. Previous studies established that microtubule structure at the cortex is disrupted in MDX myofibers; our analyses extend these findings by showing that microtubule structure in the core is also disrupted. In addition, we studied malformed MDX myofibers to better understand the role of altered myofiber morphology vs. microtubule architecture in the underlying susceptibility to injury seen in dystrophic muscles. We incorporated morphological and microtubule architectural concepts into a simplified finite element mathematical model of myofiber mechanics, which suggests a greater contribution of myofiber morphology than microtubule structure to muscle biomechanical performance.NEW & NOTEWORTHY Microtubules provide the means for nuclear movement but show altered organization in the muscular dystrophy mouse model (MDX) (dystrophin-null) muscle. Here, MDX myofibers show increased nuclear movement, altered transcriptional activity, and altered linkers of nucleoskeleton and cytoskeleton complex expression compared with healthy myofibers. Microtubule architecture was incorporated in finite element modeling of passive stretch, revealing a role of fiber malformation, commonly found in MDX muscle. The results suggest that alterations in microtubule architecture in MDX muscle affect nuclear movement, which is essential for muscle function.
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Affiliation(s)
- Shama R Iyer
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland
| | - Sameer B Shah
- Departments of Orthopaedic Surgery and Bioengineering, University of California San Diego, La Jolla, California
| | - Ana P Valencia
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland
| | - Martin F Schneider
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Erick O Hernández-Ochoa
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Joseph P Stains
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland
| | - Silvia S Blemker
- Department of Biomedical Engineering and Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia; and
| | - Richard M Lovering
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland; .,Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
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81
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Osseni A, Sébastien M, Sarrault O, Baudet M, Couté Y, Fauré J, Fourest-Lieuvin A, Marty I. Triadin and CLIMP-63 form a link between triads and microtubules in muscle cells. J Cell Sci 2016; 129:3744-3755. [PMID: 27562070 DOI: 10.1242/jcs.188862] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 08/18/2016] [Indexed: 01/20/2023] Open
Abstract
In skeletal muscle, the triad is a structure comprising a transverse (T)-tubule and sarcoplasmic reticulum (SR) cisternae. Triads constitute the basis of excitation-contraction coupling as the cradle of the Ca2+ release complex. We have shown previously that triadin, a member of this complex, has shaping properties on reticulum membrane and is indirectly involved in a link between triads and microtubules. We have identified here that CLIMP-63 (also known as CKAP4), as the partner of triadin, is responsible for this association of triads and microtubules. Triadin and CLIMP-63 interact through their respective luminal domains and the shaping properties of triadin depend on the capacity of CLIMP-63 to bind microtubules with its cytosolic portion. In skeletal muscle, CLIMP-63 is localized in the SR, including triads, and is associated with the Ca2+ release complex through its interaction with triadin. Knockout of triadin in muscles results in the delocalization of CLIMP-63 from triads, its dissociation from the Ca2+ release complex and a disorganization of the microtubule network. Our results suggest that the association of triadin and CLIMP-63 could be involved in the shaping of SR terminal cisternae and in the guidance of microtubules close to the triads.
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Affiliation(s)
- Alexis Osseni
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble F-38000, France INSERM, U1216, Grenoble F-38000, France
| | - Muriel Sébastien
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble F-38000, France INSERM, U1216, Grenoble F-38000, France
| | - Oriana Sarrault
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble F-38000, France INSERM, U1216, Grenoble F-38000, France
| | - Mathieu Baudet
- University Grenoble Alpes, BIG-BGE, Grenoble F-38000, France CEA, BIG, BGE and GPC, Grenoble F-38000, France INSERM, BGE, Grenoble F-38000, France
| | - Yohann Couté
- University Grenoble Alpes, BIG-BGE, Grenoble F-38000, France CEA, BIG, BGE and GPC, Grenoble F-38000, France INSERM, BGE, Grenoble F-38000, France
| | - Julien Fauré
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble F-38000, France INSERM, U1216, Grenoble F-38000, France CHU de Grenoble, Grenoble F-38000, France
| | - Anne Fourest-Lieuvin
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble F-38000, France INSERM, U1216, Grenoble F-38000, France CEA, BIG, BGE and GPC, Grenoble F-38000, France
| | - Isabelle Marty
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Grenoble F-38000, France INSERM, U1216, Grenoble F-38000, France
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82
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Abstract
PURPOSE OF REVIEW Gene therapy as a treatment for neuromuscular disease has significantly advanced over the past decade. In the present review, the progress of adeno-associated viruses (AAV) vector-mediated gene therapy for Duchenne muscular dystrophy (DMD) during the past year is highlighted. RECENT FINDINGS Modulating the immune response to AAV vector capsid or the transgene has helped to increase stable transduction efficiency. Full-length dystrophin expression via gene editing with targeted nucleases may ultimately be an ideal treatment option. Also genes with homologues function may ameliorate many aspects of the DMD pathophysiology. SUMMARY The work during the past year has increased our understanding of AAV vector-mediated therapy and has also validated new approaches to treat DMD. The results will aid in the design of both preclinical and clinical trials.
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83
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Abstract
The dystrophin complex stabilizes the plasma membrane of striated muscle cells. Loss of function mutations in the genes encoding dystrophin, or the associated proteins, trigger instability of the plasma membrane, and myofiber loss. Mutations in dystrophin have been extensively cataloged, providing remarkable structure-function correlation between predicted protein structure and clinical outcomes. These data have highlighted dystrophin regions necessary for in vivo function and fueled the design of viral vectors and now, exon skipping approaches for use in dystrophin restoration therapies. However, dystrophin restoration is likely more complex, owing to the role of the dystrophin complex as a broad cytoskeletal integrator. This review will focus on dystrophin restoration, with emphasis on the regions of dystrophin essential for interacting with its associated proteins and discuss the structural implications of these approaches.
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Affiliation(s)
- Quan Q Gao
- Committee on Development, Regeneration and Stem Cell Biology, The University of Chicago, Chicago, Illinois, USA
| | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University, Chicago, Chicago, Illinois, USA
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84
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Drum BML, Yuan C, Li L, Liu Q, Wordeman L, Santana LF. Oxidative stress decreases microtubule growth and stability in ventricular myocytes. J Mol Cell Cardiol 2016; 93:32-43. [PMID: 26902968 PMCID: PMC4902331 DOI: 10.1016/j.yjmcc.2016.02.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/21/2016] [Accepted: 02/12/2016] [Indexed: 02/05/2023]
Abstract
Microtubules (MTs) have many roles in ventricular myocytes, including structural stability, morphological integrity, and protein trafficking. However, despite their functional importance, dynamic MTs had never been visualized in living adult myocytes. Using adeno-associated viral vectors expressing the MT-associated protein plus end binding protein 3 (EB3) tagged with EGFP, we were able to perform live imaging and thus capture and quantify MT dynamics in ventricular myocytes in real time under physiological conditions. Super-resolution nanoscopy revealed that EB1 associated in puncta along the length of MTs in ventricular myocytes. The vast (~80%) majority of MTs grew perpendicular to T-tubules at a rate of 0.06μm∗s(-1) and growth was preferentially (82%) confined to a single sarcomere. Microtubule catastrophe rate was lower near the Z-line than M-line. Hydrogen peroxide increased the rate of catastrophe of MTs ~7-fold, suggesting that oxidative stress destabilizes these structures in ventricular myocytes. We also quantified MT dynamics after myocardial infarction (MI), a pathological condition associated with increased production of reactive oxygen species (ROS). Our data indicate that the catastrophe rate of MTs increases following MI. This contributed to decreased transient outward K(+) currents by decreasing the surface expression of Kv4.2 and Kv4.3 channels after MI. On the basis of these data, we conclude that, under physiological conditions, MT growth is directionally biased and that increased ROS production during MI disrupts MT dynamics, decreasing K(+) channel trafficking.
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Affiliation(s)
- Benjamin M L Drum
- Department of Physiology & Biophysics, University of Washington School of Medicine, Seattle, WA 98195, United States
| | - Can Yuan
- Department of Physiology & Biophysics, University of Washington School of Medicine, Seattle, WA 98195, United States
| | - Lei Li
- Department of Physiology & Biophysics, University of Washington School of Medicine, Seattle, WA 98195, United States
| | - Qinghang Liu
- Department of Physiology & Biophysics, University of Washington School of Medicine, Seattle, WA 98195, United States
| | - Linda Wordeman
- Department of Physiology & Biophysics, University of Washington School of Medicine, Seattle, WA 98195, United States
| | - L Fernando Santana
- Deparment of Physiology & Membrane Biology, University of California School of Medicine, Davis, CA 95616, United States.
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85
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Janghra N, Morgan JE, Sewry CA, Wilson FX, Davies KE, Muntoni F, Tinsley J. Correlation of Utrophin Levels with the Dystrophin Protein Complex and Muscle Fibre Regeneration in Duchenne and Becker Muscular Dystrophy Muscle Biopsies. PLoS One 2016; 11:e0150818. [PMID: 26974331 PMCID: PMC4790853 DOI: 10.1371/journal.pone.0150818] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 02/19/2016] [Indexed: 01/16/2023] Open
Abstract
Duchenne muscular dystrophy is a severe and currently incurable progressive neuromuscular condition, caused by mutations in the DMD gene that result in the inability to produce dystrophin. Lack of dystrophin leads to loss of muscle fibres and a reduction in muscle mass and function. There is evidence from dystrophin-deficient mouse models that increasing levels of utrophin at the muscle fibre sarcolemma by genetic or pharmacological means significantly reduces the muscular dystrophy pathology. In order to determine the efficacy of utrophin modulators in clinical trials, it is necessary to accurately measure utrophin levels and other biomarkers on a fibre by fibre basis within a biopsy section. Our aim was to develop robust and reproducible staining and imaging protocols to quantify sarcolemmal utrophin levels, sarcolemmal dystrophin complex members and numbers of regenerating fibres within a biopsy section. We quantified sarcolemmal utrophin in mature and regenerating fibres and the percentage of regenerating muscle fibres, in muscle biopsies from Duchenne, the milder Becker muscular dystrophy and controls. Fluorescent immunostaining followed by image analysis was performed to quantify utrophin intensity and β-dystrogylcan and ɣ –sarcoglycan intensity at the sarcolemma. Antibodies to fetal and developmental myosins were used to identify regenerating muscle fibres allowing the accurate calculation of percentage regeneration fibres in the biopsy. Our results indicate that muscle biopsies from Becker muscular dystrophy patients have fewer numbers of regenerating fibres and reduced utrophin intensity compared to muscle biopsies from Duchenne muscular dystrophy patients. Of particular interest, we show for the first time that the percentage of regenerating muscle fibres within the muscle biopsy correlate with the clinical severity of Becker and Duchenne muscular dystrophy patients from whom the biopsy was taken. The ongoing development of these tools to quantify sarcolemmal utrophin and muscle regeneration in muscle biopsies will be invaluable for assessing utrophin modulator activity in future clinical trials.
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Affiliation(s)
- Narinder Janghra
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N1EH, United Kingdom
| | - Jennifer E. Morgan
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N1EH, United Kingdom
- * E-mail:
| | - Caroline A. Sewry
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N1EH, United Kingdom
| | - Francis X. Wilson
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxfordshire, OX14 4RY, United Kingdom
| | - Kay E. Davies
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, UCL Institute of Child Health, 30 Guilford Street, London, WC1N1EH, United Kingdom
| | - Jonathon Tinsley
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxfordshire, OX14 4RY, United Kingdom
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86
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2015 William Allan Award. Am J Hum Genet 2016; 98:419-426. [PMID: 26942278 DOI: 10.1016/j.ajhg.2016.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Indexed: 11/21/2022] Open
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87
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Vainzof M, Feitosa L, Canovas M, Ayub-Guerrieri D, Pavanello RDCM, Zatz M. Concordant utrophin upregulation in phenotypically discordant DMD/BMD brothers. Neuromuscul Disord 2016; 26:197-200. [PMID: 26851826 DOI: 10.1016/j.nmd.2016.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 01/03/2016] [Accepted: 01/15/2016] [Indexed: 11/17/2022]
Abstract
Utrophin expression was investigated in two phenotypically discordant Duchenne muscular dystrophy half-brothers. The youngest was wheelchair-bound at age 9, while his mildly affected older brother was able to walk without difficulties at age 15. DNA analysis revealed an out-of-frame exon 2 duplication in the DMD gene, associated with muscle dystrophin protein deficiency. Utrophin localization and quantity was analyzed and compared in both sibs to verify whether this could explain the milder phenotype of the older brother. Immunofluorescence analysis showed a clear sarcolemmal labeling for utrophin in both of them, which was present in regenerating as well as in mature fibers. On western blot analysis, utrophin amount was increased 3.4 and 3.3 fold respectively, as compared to normal controls, while it was increased 1.7 to 4.0 fold in a group of DMD patients within the typical range of clinical progression. These data are in accordance with our previous observations suggesting no correlation between phenotype severity and utrophin up-regulation or sarcolemmal localization in dystrophinopathies. Finding the protective mechanisms in patients with milder course is of utmost interest to direct therapeutic targets.
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Affiliation(s)
- Mariz Vainzof
- Human Genome and Stem-Cell Research Center, Biosciences Institute, University of São Paulo, São Paulo, Brazil.
| | - Leticia Feitosa
- Human Genome and Stem-Cell Research Center, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | - Marta Canovas
- Human Genome and Stem-Cell Research Center, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | - Danielle Ayub-Guerrieri
- Human Genome and Stem-Cell Research Center, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | - Rita de Cássia M Pavanello
- Human Genome and Stem-Cell Research Center, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | - Mayana Zatz
- Human Genome and Stem-Cell Research Center, Biosciences Institute, University of São Paulo, São Paulo, Brazil
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88
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Eccentric Contraction-Induced Muscle Injury: Reproducible, Quantitative, Physiological Models to Impair Skeletal Muscle's Capacity to Generate Force. Methods Mol Biol 2016; 1460:3-18. [PMID: 27492161 DOI: 10.1007/978-1-4939-3810-0_1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In order to investigate the molecular and cellular mechanisms of muscle regeneration an experimental injury model is required. Advantages of eccentric contraction-induced injury are that it is a controllable, reproducible, and physiologically relevant model to cause muscle injury, with injury being defined as a loss of force generating capacity. While eccentric contractions can be incorporated into conscious animal study designs such as downhill treadmill running, electrophysiological approaches to elicit eccentric contractions and examine muscle contractility, for example before and after the injurious eccentric contractions, allows researchers to circumvent common issues in determining muscle function in a conscious animal (e.g., unwillingness to participate). Herein, we describe in vitro and in vivo methods that are reliable, repeatable, and truly maximal because the muscle contractions are evoked in a controlled, quantifiable manner independent of subject motivation. Both methods can be used to initiate eccentric contraction-induced injury and are suitable for monitoring functional muscle regeneration hours to days to weeks post-injury.
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89
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Yue Y, Binalsheikh IM, Leach SB, Domeier TL, Duan D. Prospect of gene therapy for cardiomyopathy in hereditary muscular dystrophy. Expert Opin Orphan Drugs 2015; 4:169-183. [PMID: 27340611 DOI: 10.1517/21678707.2016.1124039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Cardiac involvement is a common feature in muscular dystrophies. It presents as heart failure and/or arrhythmia. Traditionally, dystrophic cardiomyopathy is treated with symptom-relieving medications. Identification of disease-causing genes and investigation on pathogenic mechanisms have opened new opportunities to treat dystrophic cardiomyopathy with gene therapy. Replacing/repairing the mutated gene and/or targeting the pathogenic process/mechanisms using alternative genes may attenuate heart disease in muscular dystrophies. AREAS COVERED Duchenne muscular dystrophy is the most common muscular dystrophy. Duchenne cardiomyopathy has been the primary focus of ongoing dystrophic cardiomyopathy gene therapy studies. Here, we use Duchenne cardiomyopathy gene therapy to showcase recent developments and to outline the path forward. We also discuss gene therapy status for cardiomyopathy associated with limb-girdle and congenital muscular dystrophies, and myotonic dystrophy. EXPERT OPINION Gene therapy for dystrophic cardiomyopathy has taken a slow but steady path forward. Preclinical studies over the last decades have addressed many fundamental questions. Adeno-associated virus-mediated gene therapy has significantly improved the outcomes in rodent models of Duchenne and limb girdle muscular dystrophies. Validation of these encouraging results in large animal models will pave the way to future human trials.
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Affiliation(s)
- Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri
| | | | - Stacey B Leach
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri
| | - Timothy L Domeier
- Department of Medical Physiology and Pharmacology, School of Medicine, University of Missouri
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri; Department of Neurology, School of Medicine, University of Missouri
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90
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Houang EM, Haman KJ, Filareto A, Perlingeiro RC, Bates FS, Lowe DA, Metzger JM. Membrane-stabilizing copolymers confer marked protection to dystrophic skeletal muscle in vivo. Mol Ther Methods Clin Dev 2015; 2:15042. [PMID: 26623440 PMCID: PMC4641511 DOI: 10.1038/mtm.2015.42] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/01/2015] [Accepted: 10/01/2015] [Indexed: 01/16/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a fatal disease of striated muscle deterioration. A unique therapeutic approach for DMD is the use of synthetic membrane stabilizers to protect the fragile dystrophic sarcolemma against contraction-induced mechanical stress. Block copolymer-based membrane stabilizer poloxamer 188 (P188) has been shown to protect the dystrophic myocardium. In comparison, the ability of synthetic membrane stabilizers to protect fragile DMD skeletal muscles has been less clear. Because cardiac and skeletal muscles have distinct structural and functional features, including differences in the mechanism of activation, variance in sarcolemma phospholipid composition, and differences in the magnitude and types of forces generated, we speculated that optimized membrane stabilization could be inherently different. Our objective here is to use principles of pharmacodynamics to evaluate membrane stabilization therapy for DMD skeletal muscles. Results show a dramatic differential effect of membrane stabilization by optimization of pharmacodynamic-guided route of poloxamer delivery. Data show that subcutaneous P188 delivery, but not intravascular or intraperitoneal routes, conferred significant protection to dystrophic limb skeletal muscles undergoing mechanical stress in vivo. In addition, structure-function examination of synthetic membrane stabilizers further underscores the importance of copolymer composition, molecular weight, and dosage in optimization of poloxamer pharmacodynamics in vivo.
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Affiliation(s)
- Evelyne M Houang
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Karen J Haman
- Department of Chemical Engineering and Material Science, University of Minnesota, Minneapolis, Minnesota, USA
| | - Antonio Filareto
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | - Rita C Perlingeiro
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | - Frank S Bates
- Department of Chemical Engineering and Material Science, University of Minnesota, Minneapolis, Minnesota, USA
| | - Dawn A Lowe
- Rehabilitation Science and Program in Physical Therapy, University of Minnesota, Minneapolis, Minnesota, USA
| | - Joseph M Metzger
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota, USA
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91
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Péladeau C, Ahmed A, Amirouche A, Crawford Parks TE, Bronicki LM, Ljubicic V, Renaud JM, Jasmin BJ. Combinatorial therapeutic activation with heparin and AICAR stimulates additive effects on utrophin A expression in dystrophic muscles. Hum Mol Genet 2015; 25:24-43. [PMID: 26494902 DOI: 10.1093/hmg/ddv444] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/19/2015] [Indexed: 01/13/2023] Open
Abstract
Upregulation of utrophin A is an attractive therapeutic strategy for treating Duchenne muscular dystrophy (DMD). Over the years, several studies revealed that utrophin A is regulated by multiple transcriptional and post-transcriptional mechanisms, and that pharmacological modulation of these pathways stimulates utrophin A expression in dystrophic muscle. In particular, we recently showed that activation of p38 signaling causes an increase in the levels of utrophin A mRNAs and protein by decreasing the functional availability of the destabilizing RNA-binding protein called K-homology splicing regulatory protein, thereby resulting in increases in the stability of existing mRNAs. Here, we treated 6-week-old mdx mice for 4 weeks with the clinically used anticoagulant drug heparin known to activate p38 mitogen-activated protein kinase, and determined the impact of this pharmacological intervention on the dystrophic phenotype. Our results show that heparin treatment of mdx mice caused a significant ∼1.5- to 3-fold increase in utrophin A expression in diaphragm, extensor digitorum longus and tibialis anterior (TA) muscles. In agreement with these findings, heparin-treated diaphragm and TA muscle fibers showed an accumulation of utrophin A and β-dystroglycan along their sarcolemma and displayed improved morphology and structural integrity. Moreover, combinatorial drug treatment using both heparin and 5-amino-4-imidazolecarboxamide riboside (AICAR), the latter targeting 5' adenosine monophosphate-activated protein kinase and the transcriptional activation of utrophin A, caused an additive effect on utrophin A expression in dystrophic muscle. These findings establish that heparin is a relevant therapeutic agent for treating DMD, and illustrate that combinatorial treatment of heparin with AICAR may serve as an effective strategy to further increase utrophin A expression in dystrophic muscle via activation of distinct signaling pathways.
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Affiliation(s)
- Christine Péladeau
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Aatika Ahmed
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Adel Amirouche
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Tara E Crawford Parks
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Lucas M Bronicki
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Vladimir Ljubicic
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine and Centre for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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92
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Kerr JP, Robison P, Shi G, Bogush AI, Kempema AM, Hexum JK, Becerra N, Harki DA, Martin SS, Raiteri R, Prosser BL, Ward CW. Detyrosinated microtubules modulate mechanotransduction in heart and skeletal muscle. Nat Commun 2015; 6:8526. [PMID: 26446751 PMCID: PMC4633818 DOI: 10.1038/ncomms9526] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 09/01/2015] [Indexed: 01/19/2023] Open
Abstract
In striated muscle, X-ROS is the mechanotransduction pathway by which mechanical stress transduced by the microtubule network elicits reactive oxygen species. X-ROS tunes Ca(2+) signalling in healthy muscle, but in diseases such as Duchenne muscular dystrophy (DMD), microtubule alterations drive elevated X-ROS, disrupting Ca(2+) homeostasis and impairing function. Here we show that detyrosination, a post-translational modification of α-tubulin, influences X-ROS signalling, contraction speed and cytoskeletal mechanics. In the mdx mouse model of DMD, the pharmacological reduction of detyrosination in vitro ablates aberrant X-ROS and Ca(2+) signalling, and in vivo it protects against hallmarks of DMD, including workload-induced arrhythmias and contraction-induced injury in skeletal muscle. We conclude that detyrosinated microtubules increase cytoskeletal stiffness and mechanotransduction in striated muscle and that targeting this post-translational modification may have broad therapeutic potential in muscular dystrophies.
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Affiliation(s)
- Jaclyn P. Kerr
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Patrick Robison
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Guoli Shi
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Alexey I. Bogush
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Aaron M. Kempema
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Joseph K. Hexum
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Natalia Becerra
- Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genova, Genova 16146, Italy
| | - Daniel A. Harki
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Stuart S. Martin
- Marlene and Stuart Greenebaum National Cancer Institute Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Roberto Raiteri
- Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genova, Genova 16146, Italy
| | - Benjamin L. Prosser
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Christopher W. Ward
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
- Center for Biomedical Engineering and Technology (BioMET), University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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93
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Guiraud S, Aartsma-Rus A, Vieira NM, Davies KE, van Ommen GJB, Kunkel LM. The Pathogenesis and Therapy of Muscular Dystrophies. Annu Rev Genomics Hum Genet 2015; 16:281-308. [DOI: 10.1146/annurev-genom-090314-025003] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Simon Guiraud
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, OX1 3PT Oxford, United Kingdom; ,
| | - Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; ,
| | - Natassia M. Vieira
- Division of Genetics and Genomics and Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, Massachusetts 02115
- Departments of Pediatrics and Genetics, Harvard Medical School, Boston, Massachusetts 02115; ,
| | - Kay E. Davies
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, OX1 3PT Oxford, United Kingdom; ,
| | - Gert-Jan B. van Ommen
- Department of Human Genetics, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; ,
| | - Louis M. Kunkel
- Division of Genetics and Genomics and Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, Massachusetts 02115
- Departments of Pediatrics and Genetics, Harvard Medical School, Boston, Massachusetts 02115; ,
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94
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Guiraud S, Chen H, Burns DT, Davies KE. Advances in genetic therapeutic strategies for Duchenne muscular dystrophy. Exp Physiol 2015; 100:1458-67. [PMID: 26140505 PMCID: PMC4973818 DOI: 10.1113/ep085308] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/01/2015] [Indexed: 01/16/2023]
Abstract
NEW FINDINGS What is the topic of this review? This review highlights recent progress in genetically based therapies targeting the primary defect of Duchenne muscular dystrophy. What advances does it highlight? Over the last two decades, considerable progress has been made in understanding the mechanisms underlying Duchenne muscular dystrophy, leading to the development of genetic therapies. These include manipulation of the expression of the gene or related genes, the splicing of the gene and its translation, and replacement of the gene using viral approaches. Duchenne muscular dystrophy is a lethal X-linked disorder caused by mutations in the dystrophin gene. In the absence of the dystrophin protein, the link between the cytoskeleton and extracellular matrix is destroyed, and this severely compromises the strength, flexibility and stability of muscle fibres. The devastating consequence is progressive muscle wasting and premature death in Duchenne muscular dystrophy patients. There is currently no cure, and despite exhaustive palliative care, patients are restricted to a wheelchair by the age of 12 years and usually succumb to cardiac or respiratory complications in their late 20s. This review provides an update on the current genetically based therapies and clinical trials that target or compensate for the primary defect of this disease. These include dystrophin gene-replacement strategies, genetic modification techniques to restore dystrophin expression, and modulation of the dystrophin homologue, utrophin, as a surrogate to re-establish muscle function.
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Affiliation(s)
- Simon Guiraud
- Medical Research Council Functional Genomics Unit at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford, OX1 3PT, UK
| | - Huijia Chen
- Medical Research Council Functional Genomics Unit at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford, OX1 3PT, UK
| | - David T Burns
- Medical Research Council Functional Genomics Unit at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford, OX1 3PT, UK
| | - Kay E Davies
- Medical Research Council Functional Genomics Unit at the University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford, OX1 3PT, UK
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95
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Le Rumeur E. Dystrophin and the two related genetic diseases, Duchenne and Becker muscular dystrophies. Bosn J Basic Med Sci 2015; 15:14-20. [PMID: 26295289 DOI: 10.17305/bjbms.2015.636] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 07/20/2015] [Indexed: 01/01/2023] Open
Abstract
Mutations of the dystrophin DMD gene, essentially deletions of one or several exons, are the cause of two devastating and to date incurable diseases, Duchenne (DMD) and Becker (BMD) muscular dystrophies. Depending upon the preservation or not of the reading frame, dystrophin is completely absent in DMD, or present in either a mutated or a truncated form in BMD. DMD is a severe disease which leads to a premature death of the patients. Therapy approaches are evolving with the aim to transform the severe DMD in the BMD form of the disease by restoring the expression of a mutated or truncated dystrophin. These therapies are based on the assumption that BMD is a mild disease. However, this is not completely true as BMD patients are more or less severely affected and no molecular basis of this heterogeneity of the BMD form of the disease is yet understood. The aim of this review is to report for the correlation between dystrophin structures in BMD deletions in view of this heterogeneity and to emphasize that examining BMD patients in details is highly relevant to anticipate for DMD therapy effects.
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Affiliation(s)
- Elisabeth Le Rumeur
- Institut de Génétique et Développement de Rennes (IGDR), Faculté de Médecine, Rennes Cedex.
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96
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Yurchenco PD. Integrating Activities of Laminins that Drive Basement Membrane Assembly and Function. CURRENT TOPICS IN MEMBRANES 2015; 76:1-30. [PMID: 26610910 DOI: 10.1016/bs.ctm.2015.05.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Studies on extracellular matrix proteins, cells, and genetically modified animals have converged to reveal mechanisms of basement membrane self-assembly as mediated by γ1 subunit-containing laminins, the focus of this chapter. The basic model is as follows: A member of the laminin family adheres to a competent cell surface and typically polymerizes followed by laminin binding to the extracellular adaptor proteins nidogen, perlecan, and agrin. Assembly is completed by the linking of nidogen and heparan sulfates to type IV collagen, allowing it to form a second stabilizing network polymer. The assembled matrix provides structural support, anchoring the extracellular matrix to the cytoskeleton, and acts as a signaling platform. Heterogeneity of function is created in part by the isoforms of laminin that vary in their ability to polymerize and to interact with integrins, dystroglycan, and other receptors. Mutations in laminin subunits, affecting expression or LN domain-specific functions, are a cause of human diseases that include those of muscle, nerve, brain, and kidney.
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Affiliation(s)
- Peter D Yurchenco
- Department of Pathology & Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.
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97
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Guiraud S, Squire SE, Edwards B, Chen H, Burns DT, Shah N, Babbs A, Davies SG, Wynne GM, Russell AJ, Elsey D, Wilson FX, Tinsley JM, Davies KE. Second-generation compound for the modulation of utrophin in the therapy of DMD. Hum Mol Genet 2015; 24:4212-24. [PMID: 25935002 PMCID: PMC4492389 DOI: 10.1093/hmg/ddv154] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/27/2015] [Indexed: 01/06/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal, X-linked muscle-wasting disease caused by lack of the cytoskeletal protein dystrophin. There is currently no cure for DMD although various promising approaches are progressing through human clinical trials. By pharmacologically modulating the expression of the dystrophin-related protein utrophin, we have previously demonstrated in dystrophin-deficient mdx studies, daily SMT C1100 treatment significantly reduced muscle degeneration leading to improved muscle function. This manuscript describes the significant disease modifying benefits associated with daily dosing of SMT022357, a second-generation compound in this drug series with improved physicochemical properties and a more robust metabolism profile. These studies in the mdx mouse demonstrate that oral administration of SMT022357 leads to increased utrophin expression in skeletal, respiratory and cardiac muscles. Significantly, utrophin expression is localized along the length of the muscle fibre, not just at the synapse, and is fibre-type independent, suggesting that drug treatment is modulating utrophin transcription in extra-synaptic myonuclei. This results in improved sarcolemmal stability and prevents dystrophic pathology through a significant reduction of regeneration, necrosis and fibrosis. All these improvements combine to protect the mdx muscle from contraction induced damage and enhance physiological function. This detailed evaluation of the SMT C1100 drug series strongly endorses the therapeutic potential of utrophin modulation as a disease modifying therapeutic strategy for all DMD patients irrespective of their dystrophin mutation.
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Affiliation(s)
- Simon Guiraud
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK,
| | - Sarah E Squire
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Benjamin Edwards
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Huijia Chen
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - David T Burns
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Nandini Shah
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Arran Babbs
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Stephen G Davies
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Graham M Wynne
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Angela J Russell
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3PT, UK and
| | - David Elsey
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK
| | - Francis X Wilson
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK
| | - Jon M Tinsley
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK
| | - Kay E Davies
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK,
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98
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McCourt JL, Rhett KK, Jaeger MA, Belanto JJ, Talsness DM, Ervasti JM. In vitro stability of therapeutically relevant, internally truncated dystrophins. Skelet Muscle 2015; 5:13. [PMID: 25954502 PMCID: PMC4424174 DOI: 10.1186/s13395-015-0040-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Accepted: 04/14/2015] [Indexed: 12/21/2022] Open
Abstract
Background The X-linked recessive disease Duchenne muscular dystrophy (DMD) is caused by mutations in the gene encoding the protein dystrophin. Despite its large size, dystrophin is a highly stable protein, demonstrating cooperative unfolding during thermal denaturation as monitored by circular dichroism spectroscopy. In contrast, internal sequence deletions have been associated with a loss of the cooperative unfolding and cause in vitro protein aggregation. Several emerging therapy options for DMD utilize internally deleted micro-dystrophins and multi-exon-skipped dystrophins that produce partially functional proteins, but the stability of such internally truncated proteins has not been investigated. Methods In this study, we analyzed the in vitro stability of human dystrophin constructs skipped around exon 45 or exon 51, several dystrophin gene therapy constructs, as well as human full-length and micro-utrophin. Constructs were expressed in insect cells using the baculovirus system, purified by affinity chromatography, and analyzed by high-speed sedimentation, circular dichroism spectroscopy, and differential scanning fluorimetry. Results Our results reveal that not all gene therapy constructs display stabilities consistent with full-length human dystrophin. However, all dystrophins skipped in-frame around exon 45 or exon 51 show stability profiles congruent with intact human dystrophin. Similar to previous studies of mouse proteins, full-length human utrophin also displays stability similar to human dystrophin and does not appear to be affected by a large internal deletion. Conclusions Our results suggest that the in vitro stability of human dystrophin is less sensitive to smaller deletions at natural exon boundaries than larger, more complex deletions present in some gene therapy constructs.
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Affiliation(s)
- Jackie L McCourt
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455 USA
| | - Katrina K Rhett
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455 USA
| | - Michele A Jaeger
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455 USA
| | - Joseph J Belanto
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455 USA
| | - Dana M Talsness
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455 USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455 USA
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99
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Microtubule-targeting agents augment the toxicity of DNA-damaging agents by disrupting intracellular trafficking of DNA repair proteins. Proc Natl Acad Sci U S A 2015; 112:1571-6. [PMID: 25605897 DOI: 10.1073/pnas.1416418112] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The paradigm that microtubule-targeting agents (MTAs) cause cell death via mitotic arrest applies to rapidly dividing cells but cannot explain MTA activity in slowly growing human cancers. Many preferred cancer regimens combine a MTA with a DNA-damaging agent (DDA). We hypothesized that MTAs synergize with DDAs by interfering with trafficking of DNA repair proteins on interphase microtubules. We investigated nine proteins involved in DNA repair: ATM, ATR, DNA-PK, Rad50, Mre11, p95/NBS1, p53, 53BP1, and p63. The proteins were sequestered in the cytoplasm by vincristine and paclitaxel but not by an aurora kinase inhibitor, colocalized with tubulin by confocal microscopy and coimmunoprecipitated with the microtubule motor dynein. Furthermore, adding MTAs to radiation, doxorubicin, or etoposide led to more sustained γ-H2AX levels. We conclude DNA damage-repair proteins traffic on microtubules and addition of MTAs sequesters them in the cytoplasm, explaining why MTA/DDA combinations are common anticancer regimens.
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100
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Boisgérault F, Mingozzi F. The Skeletal Muscle Environment and Its Role in Immunity and Tolerance to AAV Vector-Mediated Gene Transfer. Curr Gene Ther 2015; 15:381-94. [PMID: 26122097 PMCID: PMC4515578 DOI: 10.2174/1566523215666150630121750] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 06/15/2015] [Accepted: 06/19/2015] [Indexed: 02/08/2023]
Abstract
Since the early days of gene therapy, muscle has been one the most studied tissue targets for the correction of enzyme deficiencies and myopathies. Several preclinical and clinical studies have been conducted using adeno-associated virus (AAV) vectors. Exciting progress has been made in the gene delivery technologies, from the identification of novel AAV serotypes to the development of novel vector delivery techniques. In parallel, significant knowledge has been generated on the host immune system and its interaction with both the vector and the transgene at the muscle level. In particular, the role of underlying muscle inflammation, characteristic of several diseases affecting the muscle, has been defined in terms of its potential detrimental impact on gene transfer with AAV vectors. At the same time, feedback immunomodulatory mechanisms peculiar of skeletal muscle involving resident regulatory T cells have been identified, which seem to play an important role in maintaining, at least to some extent, muscle homeostasis during inflammation and regenerative processes. Devising strategies to tip this balance towards unresponsiveness may represent an avenue to improve the safety and efficacy of muscle gene transfer with AAV vectors.
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Affiliation(s)
| | - Federico Mingozzi
- Genethon, Evry, France
- University Pierre and Marie Curie, Paris, France
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