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DiFranco M, Yu C, Quiñonez M, Vergara JL. Age-dependent chloride channel expression in skeletal muscle fibres of normal and HSA(LR) myotonic mice. J Physiol 2012; 591:1347-71. [PMID: 23247112 DOI: 10.1113/jphysiol.2012.246546] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Abstract We combine electrophysiological and optical techniques to investigate the role that the expression of chloride channels (ClC-1) plays on the age-dependent electrical properties of mammalian muscle fibres. To this end, we comparatively evaluate the magnitude and voltage dependence of chloride currents (ICl), as well as the resting resistance, in fibres isolated from control and human skeletal actin (HSA)(LR) mice (a model of myotonic dystrophy) of various ages. In control mice, the maximal peak chloride current ([peak-ICl]max) increases from -583 ± 126 to -956 ± 260 μA cm(-2) (mean ± SD) between 3 and 6 weeks old. Instead, in 3-week-old HSA(LR) mice, ICl are significantly smaller (-153 ± 33 μA cm(-2)) than in control mice, but after a long period of ∼14 weeks they reach statistically comparable values. Thus, the severe ClC-1 channelopathy in young HSA(LR) animals is slowly reversed with aging. Frequency histograms of the maximal chloride conductance (gCl,max) in fibres of young HSA(LR) animals are narrow and centred in low values; alternatively, those from older animals show broad distributions, centred at larger gCl,max values, compatible with mosaic expressions of ClC-1 channels. In fibres of both animal strains, optical data confirm the age-dependent increase in gCl, and additionally suggest that ClC-1 channels are evenly distributed between the sarcolemma and transverse tubular system membranes. Although gCl is significantly depressed in fibres of young HSA(LR) mice, the resting membrane resistance (Rm) at -90 mV is only slightly larger than in control mice due to upregulation of a Rb-sensitive resting conductance (gK,IR). In adult animals, differences in Rm are negligible between fibres of both strains, and the contributions of gCl and gK,IR are less altered in HSA(LR) animals. We surmise that while hyperexcitability in young HSA(LR) mice can be readily explained on the basis of reduced gCl, myotonia in adult HSA(LR) animals may be explained on the basis of a mosaic expression of ClC-1 channels in different fibres and/or on alterations of other conductances.
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Affiliation(s)
- Marino DiFranco
- Department of Physiology, David Geffen School of Medicine, UCLA, USA
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102
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Pereira JA, Taniguti APT, Matsumura C, Marques MJ, Neto HS. Doxycycline ameliorates the dystrophic phenotype of skeletal and cardiac muscles in mdx mice. Muscle Nerve 2012; 46:400-6. [PMID: 22907231 DOI: 10.1002/mus.23331] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
INTRODUCTION We examined whether doxycycline, an antibiotic member of the tetracycline family, improves the histopathology and muscle function in mdx mice, the experimental model of DMD. METHODS Doxycycline was administered for 36 days (starting on postnatal day 0) and for 9 months (starting at 8 months of age) in drinking water. Histopathological, biochemical (creatine kinase), and functional (forelimb muscle grip strength) parameters were evaluated in limb, diaphragm, and cardiac muscle. RESULTS Doxycycline significantly minimized the dystrophic phenotype of skeletal and cardiac muscles and improved forelimb muscle strength. The drug protected muscle fibers against myonecrosis and reduced inflammation. Furthermore, it slowed the progression of myocardial fibrosis. CONCLUSIONS This study provides evidence that doxycycline may be a potential therapeutic agent for DMD.
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Affiliation(s)
- Juliano Alves Pereira
- Departamento de Anatomia, Biologia Celular, Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, 13083-970, Brazil
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103
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Dibaj P, Zschüntzsch J, Steffens H, Scheffel J, Göricke B, Weishaupt JH, Le Meur K, Kirchhoff F, Hanisch UK, Schomburg ED, Neusch C. Influence of methylene blue on microglia-induced inflammation and motor neuron degeneration in the SOD1(G93A) model for ALS. PLoS One 2012; 7:e43963. [PMID: 22952827 PMCID: PMC3428282 DOI: 10.1371/journal.pone.0043963] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Accepted: 07/27/2012] [Indexed: 11/18/2022] Open
Abstract
Mutations in SOD1 cause hereditary variants of the fatal motor neuron disease amyotrophic lateral sclerosis (ALS). Pathophysiology of the disease is non-cell-autonomous, with toxicity deriving also from glia. In particular, microglia contribute to disease progression. Methylene blue (MB) inhibits the effect of nitric oxide, which mediates microglial responses to injury. In vivo 2P-LSM imaging was performed in ALS-linked transgenic SOD1(G93A) mice to investigate the effect of MB on microglia-mediated inflammation in the spinal cord. Local superfusion of the lateral spinal cord with MB inhibited the microglial reaction directed at a laser-induced axon transection in control and SOD1(G93A) mice. In vitro, MB at high concentrations inhibited cytokine and chemokine release from microglia of control and advanced clinical SOD1(G93A) mice. Systemic MB-treatment of SOD1(G93A) mice at early preclinical stages significantly delayed disease onset and motor dysfunction. However, an increase of MB dose had no additional effect on disease progression; this was unexpected in view of the local anti-inflammatory effects. Furthermore, in vivo imaging of systemically MB-treated mice also showed no alterations of microglia activity in response to local lesions. Thus although systemic MB treatment had no effect on microgliosis, instead, its use revealed an important influence on motor neuron survival as indicated by an increased number of lumbar anterior horn neurons present at the time of disease onset. Thus, potentially beneficial effects of locally applied MB on inflammatory events contributing to disease progression could not be reproduced in SOD1(G93A) mice via systemic administration, whereas systemic MB application delayed disease onset via neuroprotection.
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Affiliation(s)
- Payam Dibaj
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany.
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104
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Murphy KT, Allen AM, Chee A, Naim T, Lynch GS. Disruption of muscle renin-angiotensin system in AT1a-/- mice enhances muscle function despite reducing muscle mass but compromises repair after injury. Am J Physiol Regul Integr Comp Physiol 2012; 303:R321-31. [PMID: 22673782 DOI: 10.1152/ajpregu.00007.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of the renin-angiotensin system (RAS) in vasoregulation is well established, but a localized RAS exists in multiple tissues and exerts diverse functions including autonomic control and thermogenesis. The role of the RAS in the maintenance and function of skeletal muscle is not well understood, especially the role of angiotensin peptides, which appear to contribute to muscle atrophy. We tested the hypothesis that mice lacking the angiotensin type 1A receptor (AT(1A)(-/-)) would exhibit enhanced whole body and skeletal muscle function and improved regeneration after severe injury. Despite 18- to 20-wk-old AT(1A)(-/-) mice exhibiting reduced muscle mass compared with controls (P < 0.05), the tibialis anterior (TA) muscles produced a 25% higher maximum specific (normalized) force (P < 0.05). Average fiber cross-sectional area (CSA) and fiber oxidative capacity was not different between groups, but TA muscles from AT(1A)(-/-) mice had a reduced number of muscle fibers as well as a higher proportion of type IIx/b fibers and a lower proportion of type IIa fibers (P < 0.05). Measures of whole body function (grip strength, rotarod performance, locomotor activity) were all improved in AT(1A)(-/-) mice (P < 0.05). Surprisingly, the recovery of muscle mass and fiber CSA following myotoxic injury was impaired in AT(1A)(-/-) mice, in part by impaired myoblast fusion, prolonged collagen infiltration and inflammation, and delayed expression of myogenic regulatory factors. The findings support the therapeutic potential of RAS inhibition for enhancing whole body and skeletal muscle function, but they also reveal the importance of RAS signaling in the maintenance of muscle mass and for normal fiber repair after injury.
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Affiliation(s)
- Kate T Murphy
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia
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105
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Murphy KT, Chee A, Trieu J, Naim T, Lynch GS. Importance of functional and metabolic impairments in the characterization of the C-26 murine model of cancer cachexia. Dis Model Mech 2012; 5:533-45. [PMID: 22563056 PMCID: PMC3380716 DOI: 10.1242/dmm.008839] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cancer cachexia describes the progressive skeletal muscle wasting and weakness that is associated with many cancers. It impairs quality of life and accounts for >20% of all cancer-related deaths. The main outcome that affects quality of life and mortality is loss of skeletal muscle function and so preclinical models should exhibit similar functional impairments in order to maximize translational outcomes. Mice bearing colon-26 (C-26) tumors are commonly used in cancer cachexia studies but few studies have provided comprehensive assessments of physiological and metabolic impairment, especially those factors that impact quality of life. Our aim was to characterize functional impairments in mildly and severely affected cachectic mice, and determine the suitability of these mice as a preclinical model. Metabolic abnormalities are also evident in cachectic patients and we investigated whether C-26-tumor-bearing mice had similar metabolic aberrations. Twelve-week-old CD2F1 mice received a subcutaneous injection of PBS (control) or C-26 tumor cells. After 18–20 days, assessments were made of grip strength, rotarod performance, locomotor activity, whole body metabolism, and contractile properties of tibialis anterior (TA) muscles (in situ) and diaphragm muscle strips (in vitro). Injection of C-26 cells reduced body and muscle mass, and epididymal fat mass. C-26-tumor-bearing mice exhibited lower grip strength and rotarod performance. Locomotor activity was impaired following C-26 injection, with reductions in movement distance, duration and speed compared with controls. TA muscles from C-26-tumor-bearing mice had lower maximum force (−27%) and were more susceptible to fatigue. Maximum specific (normalized) force of diaphragm muscle strips was reduced (−10%) with C-26 injection, and force during fatiguing stimulation was also lower. C-26-tumor-bearing mice had reduced carbohydrate oxidation and increased fat oxidation compared with controls. The range and consistency of functional and metabolic impairments in C-26-tumor-bearing mice confirm their suitability as a preclinical model for cancer cachexia. We recommend the use of these comprehensive functional assessments to maximize the translation of findings to more accurately identify effective treatments for cancer cachexia.
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Affiliation(s)
- Kate T Murphy
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria 3010, Australia
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106
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Weller C, Zschüntzsch J, Makosch G, Metselaar JM, Klinker F, Klinge L, Liebetanz D, Schmidt J. Motor performance of young dystrophic mdx mice treated with long-circulating prednisolone liposomes. J Neurosci Res 2012; 90:1067-77. [PMID: 22253213 DOI: 10.1002/jnr.22825] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 10/19/2011] [Accepted: 10/21/2011] [Indexed: 01/12/2023]
Abstract
For Duchenne muscular dystrophy (DMD), a common myopathy that leads to severe disability, no causal therapy is available. Glucocorticosteroids improve patients' muscle strength, but their long-term use is limited by negative side effects. Thus, pharmacological modifications of glucocorticosteroids are required to increase the efficacy by drug targeting. Liposomal encapsulation augments systemic half-life and local tissue concentrations of glucocorticosteroids and, at the same time, reduces systemic side effects. In this study, the efficacy of novel, long-circulating, polyethylene-glycol-coated liposomes encapsulating prednisolone was compared with free prednisolone in the treatment of mdx mice, a well-established animal model for DMD. Using an objective and sensitive computerized 24-hr detection system of voluntary wheel-running in single cages, we demonstrate a significant impairment of the running performance in mdx compared with black/10 control mice aged 3-6 weeks. Treatment with liposomal or free prednisolone did not improve running performance compared with saline control or empty liposomes. Histopathological parameters, including the rate of internalized nuclei and fiber size variation, and mRNA and protein expression levels of transforming growth factor (TGF)-β and monocytes chemotactic protein (MCP)-1 also remained unchanged. Bioactivity in skeletal muscle of liposomal and free prednisolone was demonstrated by elevated mRNA expression of muscle ring finger protein 1 (MuRF1), a mediator of muscle atrophy, and its forkhead box transcription factors (Foxo1/3). Our data support the assessment of voluntary running to be a robust and reproducible outcome measure of skeletal muscle performance during the early disease course of mdx mice and suggest that liposomal encapsulation is not superior in treatment efficacy compared with conventional prednisolone. Our study helps to improve the future design of experimental treatment in animal models of neuromuscular diseases.
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Affiliation(s)
- Charlotte Weller
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
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107
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Davoodi J, Markert CD, Voelker KA, Hutson SM, Grange RW. Nutrition strategies to improve physical capabilities in Duchenne muscular dystrophy. Phys Med Rehabil Clin N Am 2011; 23:187-99, xii-xiii. [PMID: 22239883 DOI: 10.1016/j.pmr.2011.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
There is no current cure for Duchenne muscular dystrophy (DMD), and palliative and prophylactic interventions to improve the quality of life of patients remain limited, with the exception of corticosteroids. This article describes 2 potential nutritional interventions for the treatment of DMD, green tea extract (GTE) and the branched-chain amino acid leucine, and their positive effects on physical activity. Both GTE and leucine are suitable for human consumption, are easily tolerated with no side effects, and, with appropriate preclinical data, could be brought forward to clinical trials rapidly.
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Affiliation(s)
- J Davoodi
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
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108
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Radley-Crabb HG, Fiorotto ML, Grounds MD. The different impact of a high fat diet on dystrophic mdx and control C57Bl/10 mice. PLOS CURRENTS 2011; 3:RRN1276. [PMID: 22094293 PMCID: PMC3217191 DOI: 10.1371/currents.rrn1276] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 10/24/2011] [Indexed: 01/26/2023]
Abstract
The absence of functional dystrophin protein in patients with Duchenne muscular dystrophy (DMD) and dystrophic mdx mice leads to fragile myofibre membranes and cycles of myofibre necrosis and regeneration. It is proposed that both DMD patients and mdx mice have an altered metabolism and impaired energy status and that nutritional supplementation may reduce the severity of dystropathology. This research compares the in vivo responses of dystrophic mdx and normal control C57Bl/10 mice to a high protein (50%) or a high fat (16%) diet. Consumption of a high protein diet had minimal effects on the body composition or muscle morphology in both strains of mice. In contrast, differences between the strains were seen in response to the high fat diet; this response also varied between mdx mice aged <24 weeks, and mdx mice aged 24 - 40 weeks. C57Bl/10 mice demonstrated many negative side effects after consuming the high fat diet, including weight gain, increased body fat, and elevated inflammatory cytokines. In contrast, after consuming the high fat diet for 16 weeks the mdx mice (< 24 weeks) remained lean with minimal fat deposition and were resistant to changes in body composition. These results support the proposal that energy metabolism in dystrophic mdx mice is altered compared to normal C57Bl/10 mice and this enables the mdx mice to better metabolise the high fat diet and avoid fat deposition. However, older mdx mice (24 - 40-week-old), with increased energy intake, exhibited some mild adverse effects of a high fat diet but to a far lesser extent than age-matched C57Bl/10 mice. Benefits of the high fat diet on dystrophic muscles of young mice were demonstrated by the significantly increased running ability (km) of voluntarily exercised mdx mice and significantly reduced myofibre necrosis in 24-week-old sedentary mdx mice. These novel data clearly identify an 'altered' response to a high fat diet in dystrophic mdx compared to normal C57Bl/10 mice. Our data indicate that the high fat diet may better meet the energy needs of mdx mice to reduce muscle damage and improve muscle function.
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Affiliation(s)
- Hannah G Radley-Crabb
- School of Anatomy and Human Biology, the University of Western Australia, Perth, Australia and USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
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109
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Radley-Crabb H, Terrill J, Shavlakadze T, Tonkin J, Arthur P, Grounds M. A single 30 min treadmill exercise session is suitable for 'proof-of concept studies' in adult mdx mice: a comparison of the early consequences of two different treadmill protocols. Neuromuscul Disord 2011; 22:170-82. [PMID: 21835619 DOI: 10.1016/j.nmd.2011.07.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 06/24/2011] [Accepted: 07/11/2011] [Indexed: 11/15/2022]
Abstract
The extent of muscle pathology in sedentary adult mdx mice is very low and treadmill exercise is often used to increase myofibre necrosis; however, the early events in dystrophic muscle and blood in response to treadmill exercise (leading to myofibre necrosis) are unknown. This study describes in detail two standardised protocols for the treadmill exercise of mdx mice and profiles changes in molecular and cellular events after a single 30 min treadmill session (Protocol A) or after 4 weeks of (twice weekly) treadmill exercise (Protocol B). Both treadmill protocols increased multiple markers of muscle damage. We conclude that a single 30 min treadmill exercise session is a sufficient and conveniently fast screening test and could be used in 'proof-of-concept' studies to evaluate the benefits of pre-clinical drugs in vivo. Myofibre necrosis, blood serum CK and oxidative stress (specifically the ratio of oxidised to reduced protein thiols) are reliable markers of muscle damage after exercise; many parameters demonstrated high biological variation including changes in mRNA levels for key inflammatory cytokines in muscle. The sampling (sacrifice and tissue collection) time after exercise for these parameters is critical. A more precise understanding of the changes in dystrophic muscle after exercise aims to identify biomarkers and new potential therapeutic drug targets for Duchenne Muscular Dystrophy.
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Affiliation(s)
- Hannah Radley-Crabb
- School of Anatomy and Human Biology, The University of Western Australia, Crawley, Australia.
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110
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Cozzoli A, Rolland JF, Capogrosso RF, Sblendorio VT, Longo V, Simonetti S, Nico B, De Luca A. Evaluation of potential synergistic action of a combined treatment with alpha-methyl-prednisolone and taurine on the mdx mouse model of Duchenne muscular dystrophy. Neuropathol Appl Neurobiol 2011; 37:243-56. [PMID: 20618838 DOI: 10.1111/j.1365-2990.2010.01106.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AIMS Glucocorticoids are the sole drugs clinically used in Duchenne muscular dystrophy, in spite of the relevant side effects. Combination of glucocorticoids with synergistic drugs may be one strategy to lower doses and control side effects, meanwhile providing wider control of the complex pathology. This study is a preclinical evaluation of the effect of a combined treatment of α-methyl-prednisolone (PDN) with taurine, a safe aminoacid with positive effects on some pathology-related events. METHODS PDN (1 mg/kg/day i.p.) and taurine (1 g/kg/day orally) were administered either alone or in combination, for 4-8 weeks to male dystrophic mdx mice chronically exercised on a treadmill. Effects were assessed in vivo and ex vivo with a variety of methodological approaches. RESULTS In vivo, each treatment significantly increased fore limb strength, a marked synergistic effect being observed with the combination PDN + taurine. Ex vivo, PDN + taurine completely restored the mechanical threshold, an electrophysiological index of calcium homeostasis, of extensor digitorum longus myofibres and the benefit was greater than for PDN alone. In parallel, the overactivity of voltage-independent cation channels in dystrophic myofibres was reduced. No effects were observed on plasma levels of creatine kinase, while lactate dehydrogenase was decreased by taurine and, to a minor extent, by PDN + taurine. A similar histology profile was observed in PDN and PDN + taurine-treated muscles. PDN + taurine significantly increased taurine level in fast-twitch muscle and brain, by high-pressure liquid chromatography analysis. CONCLUSIONS The combination PDN + taurine has additive actions on in vivo and ex vivo functional end points, with less evident advantages on histopathology and biochemical markers of the disease.
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Affiliation(s)
- A Cozzoli
- Unit of Pharmacology, Department of Pharmaco-biology, Faculty of Pharmacy Department of Human Anatomy and Histology, Faculty of Medicine, University of Bari Metabolic Disease Unit, Paediatric Hospital Giovanni XXIII, Bari, Italy
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111
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Cozzoli A, Nico B, Sblendorio VT, Capogrosso RF, Dinardo MM, Longo V, Gagliardi S, Montagnani M, De Luca A. Enalapril treatment discloses an early role of angiotensin II in inflammation- and oxidative stress-related muscle damage in dystrophic mdx mice. Pharmacol Res 2011; 64:482-92. [PMID: 21689754 PMCID: PMC3184479 DOI: 10.1016/j.phrs.2011.06.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 06/02/2011] [Accepted: 06/02/2011] [Indexed: 02/06/2023]
Abstract
Inhibitors of angiotensin converting enzymes (ACE) are clinically used to control cardiomyopathy in patients of Duchenne muscular dystrophy. Various evidences suggest potential usefulness of long-term treatment with ACE inhibitors to reduce advanced fibrosis of dystrophic muscle in the mdx mouse model. However, angiotensin II is known to exert pro-inflammatory and pro-oxidative actions that might contribute to early events of dystrophic muscle degeneration. The present study has been aimed at evaluating the effects of an early treatment with enalapril on the pathology signs of exercised mdx mouse model. The effects of 1 and 5 mg/kg enalapril i.p. for 4-8 weeks have been compared with those of 1 mg/kg α-methyl-prednisolone (PDN), as positive control. Enalapril caused a dose-dependent increase in fore limb strength, the highest dose leading to a recovery score similar to that observed with PDN. A dose-dependent reduction of superoxide anion production was observed by dihydroethidium staining in tibialis anterior muscle of enalapril-treated mice, approaching the effect observed with PND. In parallel, a significant reduction of the activated form of the pro-inflammatory Nuclear Factor-kB has been observed in gastrocnemious muscle. Histologically, 5 mg/kg enalapril reduced the area of muscle necrosis in both gastrocnemious muscle and diaphragm, without significant effect on non-muscle area. In parallel no significant changes have been observed in both muscle TGF-β1 and myonuclei positive to phosphorylated Smad2/3. Myofiber functional indices were also monitored by microelectrodes recordings. A dose-dependent recovery of macroscopic chloride conductance has been observed upon enalapril treatment in EDL muscle, with minor effects being exerted in diaphragm. However a modest effect, if any, was found on mechanical threshold, a functional index of calcium homeostasis. No recovery was observed in creatine kinase and lactate dehydrogenase. Finally the results suggest the ability of enalapril to blunt angiotensin-II dependent activation of pro-inflammatory and pro-oxidant pathways which may be earlier events with respect to the pro-fibrotic ones, and may in part account for both functional impairment and muscle necrosis. The PDN-like profile may corroborate the combined use of the two classes of drugs in DMD patients so to potentiate the beneficial effects at skeletal muscle level, while reducing both spontaneous and PDN-aggravated cardiomyopathy.
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Affiliation(s)
- Anna Cozzoli
- Unit of Pharmacology, Department of Pharmaco-biology, Faculty of Pharmacy, University of Bari, Italy
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112
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Markert CD, Ambrosio F, Call JA, Grange RW. Exercise and Duchenne muscular dystrophy: toward evidence-based exercise prescription. Muscle Nerve 2011; 43:464-78. [PMID: 21404285 DOI: 10.1002/mus.21987] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To develop a rational framework for answering questions about the role of exercise in Duchenne muscular dystrophy (DMD), we focused on five pathophysiological mechanisms and offer brief hypotheses regarding how exercise may beneficially modulate pertinent cellular and molecular pathways. We aimed to provide an integrative overview of mechanisms of DMD pathology that may improve or worsen as a result of exercise. We also sought to stimulate discussion of what outcomes/dependent variables most appropriately measure these mechanisms, with the purpose of defining criteria for well-designed, controlled studies of exercise in DMD. The five mechanisms include pathways that are both intrinsic and extrinsic to the diseased muscle cells.
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Affiliation(s)
- Chad D Markert
- Wake Forest Institute for Regenerative Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157, USA.
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113
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Tinsley JM, Fairclough RJ, Storer R, Wilkes FJ, Potter AC, Squire SE, Powell DS, Cozzoli A, Capogrosso RF, Lambert A, Wilson FX, Wren SP, De Luca A, Davies KE. Daily treatment with SMTC1100, a novel small molecule utrophin upregulator, dramatically reduces the dystrophic symptoms in the mdx mouse. PLoS One 2011; 6:e19189. [PMID: 21573153 PMCID: PMC3089598 DOI: 10.1371/journal.pone.0019189] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 03/22/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is a lethal, progressive muscle wasting disease caused by a loss of sarcolemmal bound dystrophin, which results in the death of the muscle fibers leading to the gradual depletion of skeletal muscle. There is significant evidence demonstrating that increasing levels of the dystrophin-related protein, utrophin, in mouse models results in sarcolemmal bound utrophin and prevents the muscular dystrophy pathology. The aim of this work was to develop a small molecule which increases the levels of utrophin in muscle and thus has therapeutic potential. METHODOLOGY AND PRINCIPAL FINDINGS We describe the in vivo activity of SMT C1100; the first orally bioavailable small molecule utrophin upregulator. Once-a-day daily-dosing with SMT C1100 reduces a number of the pathological effects of dystrophin deficiency. Treatment results in reduced pathology, better muscle physiology leading to an increase in overall strength, and an ability to resist fatigue after forced exercise; a surrogate for the six minute walk test currently recommended as the pivotal outcome measure in human trials for DMD. CONCLUSIONS AND SIGNIFICANCE This study demonstrates proof-of-principle for the use of in vitro screening methods in allowing identification of pharmacological agents for utrophin transcriptional upregulation. The best compound identified, SMT C1100, demonstrated significant disease modifying effects in DMD models. Our data warrant the full evaluation of this compound in clinical trials in DMD patients.
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Affiliation(s)
| | - Rebecca J. Fairclough
- MRC Functional Genomics Unit, Department of Physiology Anatomy and
Genetics, University of Oxford, Oxford, United Kingdom
| | | | | | - Allyson C. Potter
- MRC Functional Genomics Unit, Department of Physiology Anatomy and
Genetics, University of Oxford, Oxford, United Kingdom
| | - Sarah E. Squire
- MRC Functional Genomics Unit, Department of Physiology Anatomy and
Genetics, University of Oxford, Oxford, United Kingdom
| | - Dave S. Powell
- MRC Functional Genomics Unit, Department of Physiology Anatomy and
Genetics, University of Oxford, Oxford, United Kingdom
| | - Anna Cozzoli
- Unit of Pharmacology, Department of Pharmaco-biology, University of Bari
“A. Moro”, Bari, Italy
| | - Roberta F. Capogrosso
- Unit of Pharmacology, Department of Pharmaco-biology, University of Bari
“A. Moro”, Bari, Italy
| | | | | | | | - Annamaria De Luca
- Unit of Pharmacology, Department of Pharmaco-biology, University of Bari
“A. Moro”, Bari, Italy
| | - Kay E. Davies
- MRC Functional Genomics Unit, Department of Physiology Anatomy and
Genetics, University of Oxford, Oxford, United Kingdom
- * E-mail: (JMT); (KED)
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114
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Wilton SD, Fletcher S. Novel compounds for the treatment of Duchenne muscular dystrophy: emerging therapeutic agents. APPLICATION OF CLINICAL GENETICS 2011; 4:29-44. [PMID: 23776365 PMCID: PMC3681176 DOI: 10.2147/tacg.s8762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The identification of dystrophin and the causative role of mutations in this gene in Duchenne and Becker muscular dystrophies (D/BMD) was expected to lead to timely development of effective therapies. Despite over 20 years of research, corticosteroids remain the only available pharmacological treatment for DMD, although significant benefits and extended life have resulted from advances in the clinical care and management of DMD individuals. Effective treatment of DMD will require dystrophin restitution in skeletal, cardiac, and smooth muscles and nonmuscle tissues; however, modulation of muscle loss and regeneration has the potential to play an important role in altering the natural history of DMD, particularly in combination with other treatments. Emerging biological, molecular, and small molecule therapeutics are showing promise in ameliorating this devastating disease, and it is anticipated that regulatory environments will need to display some flexibility in order to accommodate the new treatment paradigms.
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Affiliation(s)
- Steve D Wilton
- Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Crawley, Perth, WA, Australia
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Pre-clinical study of 21 approved drugs in the mdx mouse. Neuromuscul Disord 2011; 21:313-27. [PMID: 21392993 DOI: 10.1016/j.nmd.2011.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 01/24/2011] [Accepted: 01/26/2011] [Indexed: 10/18/2022]
Abstract
Duchenne muscular dystrophy, a genetic disease caused by the absence of functional dystrophin, remains without adequate treatment. Although great hopes are attached to gene and cell therapies, identification of active small molecules remains a valid option for new treatments. We have studied the effect of 20 approved pharmaceutical compounds on the muscles of dystrophin-deficient mdx5Cv mice. These compounds were selected as the result of a prior screen of 800 approved molecules on a dystrophin mutant of the invertebrate animal model Cænorhabditis elegans. Drugs were administered to the mice through maternal feeding since 2weeks of life and mixed in their food after the 3rd week of life. The effects of the drugs on mice were evaluated both at 6weeks and 16weeks. Each drug was tested at two concentrations. Prednisone was added to the molecule list as a positive control. To investigate treatment efficiency, more than 30 histological, biochemical and functional parameters were recorded. This extensive study reveals that tricyclics (Imipramine and Amitriptyline) are beneficial to the fast muscles of mdx mice. It also highlights a great variability of responses according to time, muscles and assays.
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116
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Costas JM, Nye DJ, Henley JB, Plochocki JH. Voluntary exercise induces structural remodeling in the hearts of dystrophin-deficient mice. Muscle Nerve 2011; 42:881-5. [PMID: 21104863 DOI: 10.1002/mus.21783] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this exploratory study, we test the hypothesis that voluntary exercise affects the progression of dystrophic changes in the left ventricle of the heart. Wild-type (C57BL/10ScSn) and dystrophin-deficient (mdx) mice, aged 7 weeks, were divided into sedentary and exercise-treated groups and tested for differences in cardiac histomorphometry. Exercised mdx mice were found to exhibit significantly enlarged ventricles and thinner lateral ventricular walls than sedentary mdx mice (P < 0.05). Trichrome staining indicated the presence of fibrotic lesions in the left ventricular myocardium in 20% of the exercised mdx group. Fibrotic lesions were not found in control or sedentary mdx mice. No histomorphometric differences were found between treatment groups in wild-type mice. Our findings suggest voluntary exercise may accelerate the progression of ventricular dilation and fibrosis in young mdx mice. The effects of exercise on cardiac remodeling should be considered during the treatment of cardiac disease in dystrophin-deficient patients.
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Affiliation(s)
- Jeffrey M Costas
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona 85308, USA
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117
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De Arcangelis V, Serra F, Cogoni C, Vivarelli E, Monaco L, Naro F. β1-syntrophin modulation by miR-222 in mdx mice. PLoS One 2010; 5:e12098. [PMID: 20856896 PMCID: PMC2938373 DOI: 10.1371/journal.pone.0012098] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 07/18/2010] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND In mdx mice, the absence of dystrophin leads to the deficiency of other components of the dystrophin-glycoprotein complex (DAPC), making skeletal muscle fibers more susceptible to necrosis. The mechanisms involved in the disappearance of the DAPC are not completely understood. The muscles of mdx mice express normal amounts of mRNA for the DAPC components, thus suggesting post-transcriptional regulation. METHODOLOGY/PRINCIPAL FINDINGS We investigated the hypothesis that DAPC reduction could be associated with the microRNA system. Among the possible microRNAs (miRs) found to be upregulated in the skeletal muscle tissue of mdx compared to wt mice, we demonstrated that miR-222 specifically binds to the 3'-UTR of β1-syntrophin and participates in the downregulation of β1-syntrophin. In addition, we documented an altered regulation of the 3'-UTR of β1-syntrophin in muscle tissue from dystrophic mice. CONCLUSION/SIGNIFICANCE These results show the importance of the microRNA system in the regulation of DAPC components in dystrophic muscle, and suggest a potential role of miRs in the pathophysiology of dystrophy.
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Affiliation(s)
| | - Filippo Serra
- Department of Histology and Medical Embryology, University Sapienza, Rome, Italy
| | - Carlo Cogoni
- Department of Cellular Biotechnology and Ematology, University Sapienza, Rome, Italy
| | - Elisabetta Vivarelli
- Department of Histology and Medical Embryology, University Sapienza, Rome, Italy
| | - Lucia Monaco
- Department of Physiology and Pharmacology, University Sapienza, Rome, Italy
| | - Fabio Naro
- Department of Histology and Medical Embryology, University Sapienza, Rome, Italy
- IIM, Pavia, Italy
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118
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Clarke WT, Edwards B, McCullagh KJA, Kemp MW, Moorwood C, Sherman DL, Burgess M, Davies KE. Syncoilin modulates peripherin filament networks and is necessary for large-calibre motor neurons. J Cell Sci 2010; 123:2543-52. [PMID: 20587592 DOI: 10.1242/jcs.059113] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Syncoilin is an atypical type III intermediate filament (IF) protein, which is expressed in muscle and is associated with the dystrophin-associated protein complex. Here, we show that syncoilin is expressed in both the central and peripheral nervous systems. Isoform Sync1 is dominant in the brain, but isoform Sync2 is dominant in the spinal cord and sciatic nerve. Peripherin is a type III IF protein that has been shown to colocalise and interact with syncoilin. Our analyses suggest that syncoilin might function to modulate formation of peripherin filament networks through binding to peripherin isoforms. Peripherin is associated with the disease amyotrophic lateral sclerosis (ALS), thus establishing a link between syncoilin and ALS. A neuronal analysis of the syncoilin-null mouse (Sync(-/-)) revealed a reduced ability in accelerating treadmill and rotarod tests. This phenotype might be attributable to the impaired function of extensor digitorum longus muscle and type IIb fibres caused by a shift from large- to small-calibre motor axons in the ventral root.
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Affiliation(s)
- W Thomas Clarke
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3PT, UK
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119
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Guerron AD, Rawat R, Sali A, Spurney CF, Pistilli E, Cha HJ, Pandey GS, Gernapudi R, Francia D, Farajian V, Escolar DM, Bossi L, Becker M, Zerr P, de la Porte S, Gordish-Dressman H, Partridge T, Hoffman EP, Nagaraju K. Functional and molecular effects of arginine butyrate and prednisone on muscle and heart in the mdx mouse model of Duchenne Muscular Dystrophy. PLoS One 2010; 5:e11220. [PMID: 20574530 PMCID: PMC2888587 DOI: 10.1371/journal.pone.0011220] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 05/07/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The number of promising therapeutic interventions for Duchenne Muscular Dystrophy (DMD) is increasing rapidly. One of the proposed strategies is to use drugs that are known to act by multiple different mechanisms including inducing of homologous fetal form of adult genes, for example utrophin in place of dystrophin. METHODOLOGY/PRINCIPAL FINDINGS In this study, we have treated mdx mice with arginine butyrate, prednisone, or a combination of arginine butyrate and prednisone for 6 months, beginning at 3 months of age, and have comprehensively evaluated the functional, biochemical, histological, and molecular effects of the treatments in this DMD model. Arginine butyrate treatment improved grip strength and decreased fibrosis in the gastrocnemius muscle, but did not produce significant improvement in muscle and cardiac histology, heart function, behavioral measurements, or serum creatine kinase levels. In contrast, 6 months of chronic continuous prednisone treatment resulted in deterioration in functional, histological, and biochemical measures. Arginine butyrate-treated mice gene expression profiling experiments revealed that several genes that control cell proliferation, growth and differentiation are differentially expressed consistent with its histone deacetylase inhibitory activity when compared to control (saline-treated) mdx mice. Prednisone and combination treated groups showed alterations in the expression of genes that control fibrosis, inflammation, myogenesis and atrophy. CONCLUSIONS/SIGNIFICANCE These data indicate that 6 months treatment with arginine butyrate can produce modest beneficial effects on dystrophic pathology in mdx mice by reducing fibrosis and promoting muscle function while chronic continuous treatment with prednisone showed deleterious effects to skeletal and cardiac muscle. Our results clearly indicate the usefulness of multiple assays systems to monitor both beneficial and toxic effects of drugs with broad range of in vivo activity.
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MESH Headings
- Animals
- Arginine/analogs & derivatives
- Arginine/pharmacology
- Arginine/therapeutic use
- Behavior, Animal/drug effects
- Butyrates/pharmacology
- Butyrates/therapeutic use
- Disease Models, Animal
- Drug Therapy, Combination
- Female
- Gene Expression Profiling
- Gene Expression Regulation/drug effects
- Heart/drug effects
- Heart/physiopathology
- Mice
- Mice, Inbred mdx
- Muscles/drug effects
- Muscles/metabolism
- Muscles/pathology
- Muscles/physiopathology
- Muscular Dystrophy, Duchenne/drug therapy
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/physiopathology
- Prednisone/pharmacology
- Prednisone/therapeutic use
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Time Factors
- Utrophin/metabolism
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Affiliation(s)
- Alfredo D. Guerron
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Rashmi Rawat
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Arpana Sali
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Christopher F. Spurney
- Division of Cardiology, Children's National Medical Center, Washington, D. C., United States of America
| | - Emidio Pistilli
- Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hee-Jae Cha
- Department of Parasitology and Genetics, Kosin University College of Medicine, Pusan, South Korea
| | - Gouri S. Pandey
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Ramkishore Gernapudi
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Dwight Francia
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Viken Farajian
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Diana M. Escolar
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Laura Bossi
- Transgene SA, Illkirch-Graffenstaden, France
| | | | | | - Sabine de la Porte
- Laboratoire de Neurobiologie Cellulaire et Moléculaire, Institut Fédératif de Neurobiologie Alfred Fessard, Cedex, France
| | - Heather Gordish-Dressman
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Terence Partridge
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Eric P. Hoffman
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
| | - Kanneboyina Nagaraju
- Center for Genetic Medicine Research, Children's National Medical Center, Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D. C., United States of America
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Friedrich O, Both M, Weber C, Schürmann S, Teichmann MDH, von Wegner F, Fink RHA, Vogel M, Chamberlain JS, Garbe C. Microarchitecture is severely compromised but motor protein function is preserved in dystrophic mdx skeletal muscle. Biophys J 2010; 98:606-16. [PMID: 20159157 DOI: 10.1016/j.bpj.2009.11.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 10/27/2009] [Accepted: 11/05/2009] [Indexed: 10/19/2022] Open
Abstract
Progressive force loss in Duchenne muscular dystrophy is characterized by degeneration/regeneration cycles and fibrosis. Disease progression may involve structural remodeling of muscle tissue. An effect on molecular motorprotein function may also be possible. We used second harmonic generation imaging to reveal vastly altered subcellular sarcomere microarchitecture in intact single dystrophic mdx muscle cells (approximately 1 year old). Myofibril tilting, twisting, and local axis deviations explain at least up to 20% of force drop during unsynchronized contractile activation as judged from cosine angle sums of myofibril orientations within mdx fibers. In contrast, in vitro motility assays showed unaltered sliding velocities of single mdx fiber myosin extracts. Closer quantification of the microarchitecture revealed that dystrophic fibers had significantly more Y-shaped sarcomere irregularities ("verniers") than wild-type fibers (approximately 130/1000 microm(3) vs. approximately 36/1000 microm(3)). In transgenic mini-dystrophin-expressing fibers, ultrastructure was restored (approximately 38/1000 microm(3) counts). We suggest that in aged dystrophic toe muscle, progressive force loss is reflected by a vastly deranged micromorphology that prevents a coordinated and aligned contraction. Second harmonic generation imaging may soon be available in routine clinical diagnostics, and in this work we provide valuable imaging tools to track and quantify ultrastructural worsening in Duchenne muscular dystrophy, and to judge the beneficial effects of possible drug or gene therapies.
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Affiliation(s)
- O Friedrich
- Medical Biophysics, Institute of Physiology and Pathophysiology, Ruprecht Karls University, Heidelberg, Germany.
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121
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Wooddell CI, Zhang G, Griffin JB, Hegge JO, Huss T, Wolff JA. Use of Evans blue dye to compare limb muscles in exercised young and old mdx mice. Muscle Nerve 2010; 41:487-99. [PMID: 19813196 DOI: 10.1002/mus.21527] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Evans blue dye (EBD) is used to mark damaged and permeable muscle fibers in mouse models of muscular dystrophy and as an endpoint in therapeutic trials. We counted EBD-positive muscle fibers and extracted EBD from muscles sampled throughout the hindlimbs in young adult and old mdx mice to determine if the natural variability in morphology would allow measurement of a functional improvement in one limb compared to the contralateral limb. Following one bout of rotarod or treadmill exercise that greatly increased serum creatine kinase levels, the number of EBD(+) muscle fibers in 12-19-month-old mdx mice increased 3-fold, EBD in the muscles increased, and, importantly, contralateral pairs of muscles contained similar amounts of EBD. In contrast, the intra- and interlimb amounts of EBD in 2-7-month-old mdx mice were much too variable. A therapeutic effect can more readily be measured in old mdx mice. These results will be useful in the design of therapy protocols using the mdx mouse.
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122
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A 3 months mild functional test regime does not affect disease parameters in young mdx mice. Neuromuscul Disord 2010; 20:273-80. [DOI: 10.1016/j.nmd.2010.02.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 01/26/2010] [Accepted: 02/08/2010] [Indexed: 11/23/2022]
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123
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Zhang G, Wooddell CI, Hegge JO, Griffin JB, Huss T, Braun S, Wolff JA. Functional Efficacy of Dystrophin Expression from Plasmids Delivered to mdx Mice by Hydrodynamic Limb Vein Injection. Hum Gene Ther 2010; 21:221-37. [DOI: 10.1089/hum.2009.133] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Guofeng Zhang
- Department of Pediatrics and Department of Medical Genetics, Waisman Center, University of Wisconsin-Madison, Madison, WI 53705
- Present address: Roche Madison, Madison, WI 53711
| | | | | | | | | | - Serge Braun
- Association Française contre les Myopathies, Evry 91002, France
| | - Jon A. Wolff
- Department of Pediatrics and Department of Medical Genetics, Waisman Center, University of Wisconsin-Madison, Madison, WI 53705
- Present address: Roche Madison, Madison, WI 53711
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Spurney CF, Cha HJ, Sali A, Pandey GS, Pistilli E, Guerron AD, Gordish-Dressman H, Hoffman EP, Nagaraju K. Evaluation of skeletal and cardiac muscle function after chronic administration of thymosin beta-4 in the dystrophin deficient mouse. PLoS One 2010; 5:e8976. [PMID: 20126456 PMCID: PMC2813286 DOI: 10.1371/journal.pone.0008976] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 12/29/2009] [Indexed: 01/22/2023] Open
Abstract
Thymosin beta-4 (Tβ4) is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. We studied the effects of chronic administration of Tβ4 on the skeletal and cardiac muscle of dystrophin deficient mdx mice, the mouse model of Duchenne muscular dystrophy. Female wild type (C57BL10/ScSnJ) and mdx mice, 8–10 weeks old, were treated with 150 µg of Tβ4 twice a week for 6 months. To promote muscle pathology, mice were exercised for 30 minutes twice a week. Skeletal and cardiac muscle function were assessed via grip strength and high frequency echocardiography. Localization of Tβ4 and amount of fibrosis were quantified using immunohistochemistry and Gomori's tri-chrome staining, respectively. Mdx mice treated with Tβ4 showed a significant increase in skeletal muscle regenerating fibers compared to untreated mdx mice. Tβ4 stained exclusively in the regenerating fibers of mdx mice. Although untreated mdx mice had significantly decreased skeletal muscle strength compared to untreated wild type, there were no significant improvements in mdx mice after treatment. Systolic cardiac function, measured as percent shortening fraction, was decreased in untreated mdx mice compared to untreated wild type and there was no significant difference after treatment in mdx mice. Skeletal and cardiac muscle fibrosis were also significantly increased in untreated mdx mice compared to wild type, but there was no significant improvement in treated mdx mice. In exercised dystrophin deficient mice, chronic administration of Tβ4 increased the number of regenerating fibers in skeletal muscle and could have a potential role in treatment of skeletal muscle disease in Duchenne muscular dystrophy.
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Affiliation(s)
- Christopher F. Spurney
- Division of Cardiology, Children's National Medical Center, Washington, District of Columbia, United States of America
| | - Hee-Jae Cha
- Department of Parasitology and Genetics, Kosin University College of Medicine, Amnam-dong, Seo-gu, Busan, South Korea
| | - Arpana Sali
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, District of Columbia, United States of America
| | - Gouri S. Pandey
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, District of Columbia, United States of America
| | - Emidio Pistilli
- Pennsylvania Muscle Institute, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alfredo D. Guerron
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, District of Columbia, United States of America
| | - Heather Gordish-Dressman
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, District of Columbia, United States of America
| | - Eric P. Hoffman
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, District of Columbia, United States of America
| | - Kanneboyina Nagaraju
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, District of Columbia, United States of America
- * E-mail:
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Carlson CG, Rutter J, Bledsoe C, Singh R, Hoff H, Bruemmer K, Sesti J, Gatti F, Berge J, McCarthy L. A simple protocol for assessing inter-trial and inter-examiner reliability for two noninvasive measures of limb muscle strength. J Neurosci Methods 2009; 186:226-30. [PMID: 19917311 DOI: 10.1016/j.jneumeth.2009.11.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 11/06/2009] [Accepted: 11/09/2009] [Indexed: 10/20/2022]
Abstract
Noninvasive measures of limb muscle strength are quite useful in preclinical translational studies that use mouse models of muscle disease, peripheral nerve disease, and movement disorders. The present study uses a simple protocol for assessing both inter-trial and inter-examiner reliability for two noninvasive methods of assessing limb strength in dystrophic (mdx) and wild type mice. One method, termed the whole body tension (WBT) method or escape test, measures the total phasic pulling tension exerted by the fore- and hindlimbs while a mouse attempts to escape into a darkened tube. Another procedure, termed the four limb wire grid holding test, measures the minimal amount of sustained tension (physical impulse) exerted by the fore- and hindlimbs while the mouse hangs suspended in an upside-down position. A comparison of the two methods revealed significant inter-trial and inter-examiner correlations in each procedure, although the WBT procedure consistently produced higher correlations than the four limb wire grid holding test. Inter-trial reliability for each test was higher than inter-examiner reliability, indicating that each longitudinal series of tests is best performed by a single investigator. The holding test also did not consistently detect differences between wild type and mdx populations at ages greater than 4 months. These results demonstrate the utility of a simple protocol for assessing the reliability of noninvasive tests that measure limb strength, and should be useful in comparing different functional measures in a broad range of translational studies.
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Affiliation(s)
- C George Carlson
- Department of Physiology, Kirksville College of Osteopathic Medicine, AT Still University, 800 West Jefferson St., Kirksville, MO 63501, USA.
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126
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Baltgalvis KA, Call JA, Nikas JB, Lowe DA. Effects of prednisolone on skeletal muscle contractility in mdx mice. Muscle Nerve 2009; 40:443-54. [PMID: 19618428 DOI: 10.1002/mus.21327] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Current treatment for Duchenne muscular dystrophy (DMD) is chronic administration of the glucocorticoid prednisolone. Prednisolone improves muscle strength in boys with DMD, but the mechanism is unknown. The purpose of this study was to determine how prednisolone improves muscle strength by examining muscle contractility in dystrophic mice over time and in conjunction with eccentric injury. Mdx mice began receiving prednisolone (n = 23) or placebo (n = 16) at 5 weeks of age. Eight weeks of prednisolone increased specific force of the extensor digitorum longus muscle 26%, but other parameters of contractility were not affected. Prednisolone also improved the histological appearance of muscle by decreasing the number of centrally nucleated fibers. Prednisolone treatment did not affect force loss during eccentric contractions or recovery of force following injury. These data are of clinical relevance, because the increase in muscle strength in boys with DMD taking prednisolone does not appear to occur via the same mechanism in dystrophic mice.
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Affiliation(s)
- Kristen A Baltgalvis
- Department of Biochemistry, University of Minnesota Medical School, 321 Church St. SE, Jackson Hall, 6-155, Minneapolis, Minnesota 55455, USA.
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127
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Spurney CF, Gordish-Dressman H, Guerron AD, Sali A, Pandey GS, Rawat R, Van Der Meulen JH, Cha HJ, Pistilli EE, Partridge TA, Hoffman EP, Nagaraju K. Preclinical drug trials in the mdx mouse: assessment of reliable and sensitive outcome measures. Muscle Nerve 2009; 39:591-602. [PMID: 19260102 DOI: 10.1002/mus.21211] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The availability of animal models for Duchenne muscular dystrophy has led to extensive preclinical research on potential therapeutics. Few studies have focused on reliability and sensitivity of endpoints for mdx mouse drug trials. Therefore, we sought to compare a wide variety of reported and novel endpoint measures in exercised mdx and normal control mice at 10, 20, and 40 weeks of age. Statistical analysis as well as power calculations for expected effect sizes in mdx preclinical drug trials across different ages showed that body weight, normalized grip strength, horizontal activity, rest time, cardiac function measurements, blood pressure, total central/peripheral nuclei per fiber, and serum creatine kinase are the most effective measurements for detecting drug-induced changes. These data provide an experimental basis upon which standardization of preclinical drug testing can be developed. Muscle Nerve, 2008.
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Affiliation(s)
- Christopher F Spurney
- Research Center for Genetic Medicine, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA
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128
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Burdi R, Rolland JF, Fraysse B, Litvinova K, Cozzoli A, Giannuzzi V, Liantonio A, Camerino GM, Sblendorio V, Capogrosso RF, Palmieri B, Andreetta F, Confalonieri P, De Benedictis L, Montagnani M, De Luca A. Multiple pathological events in exercised dystrophic mdx mice are targeted by pentoxifylline: outcome of a large array of in vivo and ex vivo tests. J Appl Physiol (1985) 2009; 106:1311-24. [DOI: 10.1152/japplphysiol.90985.2008] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The phosphodiesterases inhibitor pentoxifylline gained attention for Duchenne muscular dystrophy therapy for its claimed anti-inflammatory, antioxidant, and antifibrotic action. A recent finding also showed that pentoxifylline counteracts the abnormal overactivity of a voltage-independent calcium channel in myofibers of dystrophic mdx mice. The possible link between workload, altered calcium homeostasis, and oxidative stress pushed toward a more detailed investigation. Thus a 4- to 8-wk treatment with pentoxifylline (50 mg·kg−1·day−1 ip) was performed in mdx mice, undergoing or not a chronic exercise on treadmill. In vivo, the treatment partially increased forelimb strength and enhanced resistance to treadmill running in exercised animals. Ex vivo, pentoxifylline restored the mechanical threshold, an electrophysiological index of calcium homeostasis, and reduced resting cytosolic calcium in extensor digitorum longus muscle fibers. Mn quenching and patch-clamp technique confirmed that this effect was paralleled by a drug-induced reduction of membrane permeability to calcium. The treatment also significantly enhanced isometric tetanic tension in mdx diaphragm. The plasma levels of creatine kinase and reactive oxygen species were both significantly reduced in treated-exercised animals. Dihydroethidium staining, used as an indicator of reactive oxygen species production, showed that pentoxifylline significantly reduced the exercise-induced increase in fluorescence in the mdx tibialis anterior muscle. A significant decrease in connective tissue area and profibrotic cytokine transforming growth factor-β1 was solely found in tibialis anterior muscle. In both diaphragm and gastrocnemius muscle, a significant increase in neural cell adhesion molecule-positive area was instead observed. This data supports the interest toward pentoxifylline and allows insight in the level of cross talk between pathogenetic events in workloaded dystrophic muscle.
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129
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Matsumura CY, Pertille A, Albuquerque TC, Santo Neto H, Marques MJ. Diltiazem and verapamil protect dystrophin-deficient muscle fibers ofMDXmice from degeneration: A potential role in calcium buffering and sarcolemmal stability. Muscle Nerve 2009; 39:167-76. [DOI: 10.1002/mus.21188] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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130
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Teichmann MDH, Wegner FV, Fink RHA, Chamberlain JS, Launikonis BS, Martinac B, Friedrich O. Inhibitory control over Ca(2+) sparks via mechanosensitive channels is disrupted in dystrophin deficient muscle but restored by mini-dystrophin expression. PLoS One 2008; 3:e3644. [PMID: 18982068 PMCID: PMC2575405 DOI: 10.1371/journal.pone.0003644] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 10/17/2008] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In dystrophic skeletal muscle, osmotic stimuli somehow relieve inhibitory control of dihydropyridine receptors (DHPR) on spontaneous sarcoplasmic reticulum elementary Ca(2+) release events (ECRE) in high Ca(2+) external environments. Such 'uncontrolled' Ca(2+) sparks were suggested to act as dystrophic signals. They may be related to mechanosensitive pathways but the mechanisms are elusive. Also, it is not known whether truncated dystrophins can correct the dystrophic disinhibition. METHODOLOGY/PRINCIPAL FINDINGS We recorded ECRE activity in single intact fibers from adult wt, mdx and mini-dystrophin expressing mice (MinD) under resting isotonic conditions and following hyper-/hypo-osmolar external shock using confocal microscopy and imaging techniques. Isotonic ECRE frequencies were small in wt and MinD fibers, but were markedly increased in mdx fibers. Osmotic challenge dramatically increased ECRE activity in mdx fibers. Sustained osmotic challenge induced marked exponential ECRE activity adaptation that was three times faster in mdx compared to wt and MinD fibers. Rising external Ca(2+) concentrations amplified osmotic ECRE responses. The eliminated ECRE suppression in intact osmotically stressed mdx fibers was completely and reversibly resuscitated by streptomycine (200 microM), spider peptide GsMTx-4 (5 microM) and Gd(3+) (20 microM) that block unspecific, specific cationic and Ca(2+) selective mechanosensitive channels (MsC), respectively. ECRE morphology was not substantially altered by membrane stress. During hyperosmotic challenge, membrane potentials were polarised and a putative depolarisation through aberrant MsC negligible excluding direct activation of ECRE through tubular depolarisation. CONCLUSIONS/SIGNIFICANCE Dystrophin suppresses spontaneous ECRE activity by control of mechanosensitive pathways which are suggested to interact with the inhibitory DHPR loop to the ryanodine receptor. MsC-related disinhibition prevails in dystrophic muscle and can be resuscitated by transgenic mini-dystrophin expression. Our results have important implications for the pathophysiology of DMD where abnormal MsC in dystrophic muscle confer disruption of microdomain Ca(2+) homeostasis. MsC blockers should have considerable therapeutic potential if more muscle specific compounds can be found.
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MESH Headings
- Adult
- Animals
- Calcium Channels, L-Type/metabolism
- Calcium Signaling/physiology
- Dystrophin/genetics
- Dystrophin/metabolism
- Humans
- Ion Channels/metabolism
- Mechanotransduction, Cellular/physiology
- Membrane Potentials/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Mice, Transgenic
- Muscle Fibers, Skeletal/cytology
- Muscle Fibers, Skeletal/physiology
- Muscle, Skeletal/cytology
- Muscle, Skeletal/physiology
- Muscle, Skeletal/physiopathology
- Muscular Dystrophy, Duchenne/physiopathology
- Osmotic Pressure
- Ryanodine Receptor Calcium Release Channel/metabolism
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Affiliation(s)
- Martin D. H. Teichmann
- Medical Biophysics, Department of Systems Physiology, Institute of Physiology and Pathophysiology, Ruprecht-Karls-University, Heidelberg, Germany
| | - Frederic v. Wegner
- Medical Biophysics, Department of Systems Physiology, Institute of Physiology and Pathophysiology, Ruprecht-Karls-University, Heidelberg, Germany
| | - Rainer H. A. Fink
- Medical Biophysics, Department of Systems Physiology, Institute of Physiology and Pathophysiology, Ruprecht-Karls-University, Heidelberg, Germany
| | - Jeffrey S. Chamberlain
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Bradley S. Launikonis
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Boris Martinac
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Oliver Friedrich
- Medical Biophysics, Department of Systems Physiology, Institute of Physiology and Pathophysiology, Ruprecht-Karls-University, Heidelberg, Germany
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
- * E-mail:
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131
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Ridgley JA, Pinniger GJ, Hamer PW, Grounds MD. The physiological effects of IGF-1 (class 1:Ea transgene) over-expression on exercise-induced damage and adaptation in dystrophic muscles of mdx mice. Pflugers Arch 2008; 457:1121-32. [DOI: 10.1007/s00424-008-0568-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 07/24/2008] [Accepted: 07/29/2008] [Indexed: 10/21/2022]
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132
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De Luca A, Nico B, Rolland JF, Cozzoli A, Burdi R, Mangieri D, Giannuzzi V, Liantonio A, Cippone V, De Bellis M, Nicchia GP, Camerino GM, Frigeri A, Svelto M, Camerino DC. Gentamicin treatment in exercised mdx mice: Identification of dystrophin-sensitive pathways and evaluation of efficacy in work-loaded dystrophic muscle. Neurobiol Dis 2008; 32:243-53. [PMID: 18694830 DOI: 10.1016/j.nbd.2008.07.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 06/10/2008] [Accepted: 07/03/2008] [Indexed: 11/08/2022] Open
Abstract
Aminoglycosides force read through of premature stop codon mutations and introduce new mutation-specific gene-corrective strategies in Duchenne muscular dystrophy. A chronic treatment with gentamicin (32 mg/kg/daily i.p., 8-12 weeks) was performed in exercised mdx mice with the dual aim to clarify the dependence on dystrophin of the functional, biochemical and histological alterations present in dystrophic muscle and to verify the long term efficiency of small molecule gene-corrective strategies in work-loaded dystrophic muscle. The treatment counteracted the exercise-induced impairment of in vivo forelimb strength after 6-8 weeks. We observed an increase in dystrophin expression level in all the fibers, although lower than that observed in normal fibers, and found a concomitant recovery of aquaporin-4 at sarcolemma. A significant reduction in centronucleated fibers, in the area of necrosis and in the percentage of nuclear factor-kB-positive nuclei was observed in gastrocnemious muscle of treated animals. Plasma creatine kinase was reduced by 70%. Ex vivo, gentamicin restored membrane ionic conductance in mdx diaphragm and limb muscle fibers. No effects were observed on the altered calcium homeostasis and sarcolemmal calcium permeability, detected by electrophysiological and microspectrofluorimetric approaches. Thus, the maintenance of a partial level of dystrophin is sufficient to reinforce sarcolemmal stability, reducing leakiness, inflammation and fiber damage, while correction of altered calcium homeostasis needs greater expression of dystrophin or direct interventions on the channels involved.
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Affiliation(s)
- Annamaria De Luca
- Unit of Pharmacology, Department of Pharmacobiology, Faculty of Pharmacy, University of Bari, Italy.
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133
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Grounds MD, Radley HG, Lynch GS, Nagaraju K, De Luca A. Towards developing standard operating procedures for pre-clinical testing in the mdx mouse model of Duchenne muscular dystrophy. Neurobiol Dis 2008; 31:1-19. [PMID: 18499465 DOI: 10.1016/j.nbd.2008.03.008] [Citation(s) in RCA: 247] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 03/20/2008] [Accepted: 03/24/2008] [Indexed: 11/19/2022] Open
Abstract
This review discusses various issues to consider when developing standard operating procedures for pre-clinical studies in the mdx mouse model of Duchenne muscular dystrophy (DMD). The review describes and evaluates a wide range of techniques used to measure parameters of muscle pathology in mdx mice and identifies some basic techniques that might comprise standardised approaches for evaluation. While the central aim is to provide a basis for the development of standardised procedures to evaluate efficacy of a drug or a therapeutic strategy, a further aim is to gain insight into pathophysiological mechanisms in order to identify other therapeutic targets. The desired outcome is to enable easier and more rigorous comparison of pre-clinical data from different laboratories around the world, in order to accelerate identification of the best pre-clinical therapies in the mdx mouse that will fast-track translation into effective clinical treatments for DMD.
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Affiliation(s)
- Miranda D Grounds
- School of Anatomy and Human Biology, the University of Western Australia, Perth, Western Australia, Australia.
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134
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McLoon LK. Focusing on fibrosis: halofuginone-induced functional improvement in the mdx mouse model of Duchenne muscular dystrophy. Am J Physiol Heart Circ Physiol 2008; 294:H1505-7. [DOI: 10.1152/ajpheart.00176.2008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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135
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Pierno S, Nico B, Burdi R, Liantonio A, Didonna MP, Cippone V, Fraysse B, Rolland JF, Mangieri D, Andreetta F, Ferro P, Camerino C, Zallone A, Confalonieri P, De Luca A. Role of tumour necrosis factor alpha, but not of cyclo-oxygenase-2-derived eicosanoids, on functional and morphological indices of dystrophic progression in mdx mice: a pharmacological approach. Neuropathol Appl Neurobiol 2007; 33:344-59. [PMID: 17493014 DOI: 10.1111/j.1365-2990.2007.00798.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The role of tumour necrosis factor (TNF)-alpha or cyclo-oxygenase-2 (COX-2) eicosanoids in dystrophinopathies has been evaluated by chronically treating (4-8 weeks) adult dystrophic mdx mice with the anti-TNF-alpha etanercept (0.5 mg/kg) or the COX-2 inhibitor meloxicam (0.2 mg/kg). Throughout the treatment period the mdx mice underwent a protocol of exercise on treadmill in order to worsen the pathology progression; gastrocnemious muscles from exercised mdx mice showed an intense staining for TNF-alpha by immunohistochemistry. In vivo, etanercept, but not meloxicam, contrasted the exercise-induced forelimb force drop. Electrophysiological recordings ex vivo, showed that etanercept counteracted the decrease in chloride channel function (gCl), a functional index of myofibre damage, in both diaphragm and extensor digitorum longus (EDL) muscle, meloxicam being effective only in EDL muscle. None of the drugs ameliorated calcium homeostasis detected by electrophysiology and/or spectrofluorimetry. Etanercept, more than meloxicam, effectively reduced plasma creatine kinase (CK). Etanercept-treated muscles showed a reduction of connective tissue area and of pro-fibrotic cytokine TGF-beta1 vs. untreated ones; however, the histological profile was weakly ameliorated. In order to better evaluate the impact of etanercept treatment on histology, a 4-week treatment was performed on 2-week-old mdx mice, so to match the first spontaneous degeneration cycle. The histology profile of gastrocnemious was significantly improved with a reduction of degenerating area; however, CK levels were only slightly lower. The present results support a key role of TNF-alpha, but not of COX-2 products, in different phases of dystrophic progression. Anti-TNF-alpha drugs may be useful in combined therapies for Duchenne patients.
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Affiliation(s)
- S Pierno
- Unit of Pharmacology, Department of Pharmacobiology, Faculty of Pharmacy, University of Bari, Bari, Italy
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136
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Lynch GS, Schertzer JD, Ryall JG. Therapeutic approaches for muscle wasting disorders. Pharmacol Ther 2007; 113:461-87. [PMID: 17258813 DOI: 10.1016/j.pharmthera.2006.11.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 11/10/2006] [Accepted: 11/10/2006] [Indexed: 12/12/2022]
Abstract
Muscle wasting and weakness are common in many disease states and conditions including aging, cancer cachexia, sepsis, denervation, disuse, inactivity, burns, HIV-acquired immunodeficiency syndrome (AIDS), chronic kidney or heart failure, unloading/microgravity, and muscular dystrophies. Although the maintenance of muscle mass is generally regarded as a simple balance between protein synthesis and protein degradation, these mechanisms are not strictly independent, but in fact they are coordinated by a number of different and sometimes complementary signaling pathways. Clearer details are now emerging about these different molecular pathways and the extent to which these pathways contribute to the etiology of various muscle wasting disorders. Therapeutic strategies for attenuating muscle wasting and improving muscle function vary in efficacy. Exercise and nutritional interventions have merit for slowing the rate of muscle atrophy in some muscle wasting conditions, but in most cases they cannot halt or reverse the wasting process. Hormonal and/or other drug strategies that can target key steps in the molecular pathways that regulate protein synthesis and protein degradation are needed. This review describes the signaling pathways that maintain muscle mass and provides an overview of some of the major conditions where muscle wasting and weakness are indicated. The review provides details on some therapeutic strategies that could potentially attenuate muscle atrophy, promote muscle growth, and ultimately improve muscle function. The emphasis is on therapies that can increase muscle mass and improve functional outcomes that will ultimately lead to improvement in the quality of life for affected patients.
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Affiliation(s)
- Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria 3010, Australia.
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137
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Liantonio A, Giannuzzi V, Cippone V, Camerino GM, Pierno S, Camerino DC. Fluvastatin and Atorvastatin Affect Calcium Homeostasis of Rat Skeletal Muscle Fibers in Vivo and in Vitro by Impairing the Sarcoplasmic Reticulum/Mitochondria Ca2+-Release System. J Pharmacol Exp Ther 2007; 321:626-34. [PMID: 17293561 DOI: 10.1124/jpet.106.118331] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The mechanism by which the 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins) induce skeletal muscle injury is still under debate. By using fura-2 cytofluorimetry on intact extensor digitorum longus muscle fibers, here we provided the first evidence that 2 months in vivo chronic treatment of rats with fluvastatin (5 and 20 mg kg-1) and atorvastatin (5 and 10 mg kg-1) caused an alteration of calcium homeostasis. All treated animals showed a significant increase of resting cytosolic calcium [Ca2+]i, up to 60% with the higher fluvastatin dose and up to 20% with the other treatments. The [Ca2+]i rise induced by statin administration was not due to an increase of sarcolemmal permeability to calcium. Furthermore, the treatments reduced caffeine responsiveness. In vitro application of fluvastatin caused changes of [Ca2+]i, resembling the effect obtained after the in vivo administration. Indeed, fluvastatin produced a shift of mechanical threshold for contraction toward negative potentials and an increase of resting [Ca2+]i. By using ruthenium red and cyclosporine A, we determined the sequence of the statin-induced Ca2+ release mechanism. Mitochondria appeared as the cellular structure responsible for the earlier event leading to a subsequent large sarcoplasmic reticulum Ca2+ release. In conclusion, we suggest that calcium homeostasis alteration may be a crucial event for myotoxicity induced by this widely used class of hypolipidemic drugs.
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Affiliation(s)
- Antonella Liantonio
- Section of Pharmacology, Dept. of Pharmacobiology, Faculty of Pharmacy, University of Bari, Via Orabona, 4, I-70125 Bari, Italy
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138
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Hopf FW, Turner PR, Steinhardt RA. Calcium misregulation and the pathogenesis of muscular dystrophy. Subcell Biochem 2007; 45:429-464. [PMID: 18193647 DOI: 10.1007/978-1-4020-6191-2_16] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Although the exact nature of the relationship between calcium and the pathogenesis of Duchenne muscular dystrophy (DMD) is not fully understood, this is an important issue which has been addressed in several recent reviews (Alderton and Steinhardt, 2000a, Gailly, 2002, Allen et al., 2005). A key question when trying to understand the cellular basis of DMD is how the absence or low level of expression of dystrophin, a cytoskeletal protein, results in the slow but progressive necrosis of muscle fibres. Although loss of cytoskeletal and sarcolemmal integrity which results from the absence of dystrophin clearly plays a key role in the pathogenesis associated with DMD, a number of lines of evidence also establish a role for misregulation of calcium ions in the DMD pathology, particularly in the cytoplasmic space just under the sarcolemma. A number of calcium-permeable channels have been identified which can exhibit greater activity in dystrophic muscle cells, and exIsting evidence suggests that these may represent different variants of the same channel type (perhaps the transient receptor potential channel, TRPC). In addition, a prominent role for calcium-activated proteases in the DMD pathology has been established, as well as modulation of other intracellular regulatory proteins and signaling pathways. Whether dystrophin and its associated proteins have a direct role in the regulation of calcium ions, calcium channels or intracellular calcium stores, or indirectly alters calcium regulation through enhancement of membrane tearing, remains unclear. Here we focus on areas of consensus or divergence amongst the existing literature, and propose areas where future research would be especially valuable.
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Affiliation(s)
- F W Hopf
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, 5858 Horton St., Suite 200, Emeryville, CA 94608, USA.
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139
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Liantonio A, Giannuzzi V, Picollo A, Babini E, Pusch M, Conte Camerino D. Niflumic acid inhibits chloride conductance of rat skeletal muscle by directly inhibiting the CLC-1 channel and by increasing intracellular calcium. Br J Pharmacol 2006; 150:235-47. [PMID: 17128287 PMCID: PMC2042903 DOI: 10.1038/sj.bjp.0706954] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE Given the crucial role of the skeletal muscle chloride conductance (gCl), supported by the voltage-gated chloride channel CLC-1, in controlling muscle excitability, the availability of ligands modulating CLC-1 are of potential medical as well as toxicological importance. Here, we focused our attention on niflumic acid (NFA), a molecule belonging to the fenamates group of non-steroidal anti-inflammatory drugs (NSAID). EXPERIMENTAL APPROACH Rat muscle Cl(-) conductance (gCl) and heterologously expressed CLC-1 currents were evaluated by means of current-clamp (using two-microelectrodes) and patch-clamp techniques, respectively. Fura-2 fluorescence was used to determine intracellular calcium concentration, [Ca(2+)](i), in native muscle fibres. KEY RESULTS NFA inhibited native gCl with an IC(50) of 42 muM and blocked CLC-1 by interacting with an intracellular binding site. Additionally, NFA increased basal [Ca(2+)](i) in myofibres by promoting a mitochondrial calcium efflux that was not dependent on cyclooxygenase or CLC-1. A structure-activity study revealed that the molecular conditions that mediate the two effects are different. Pretreatment with the Ca-dependent protein kinase C (PKC) inhibitor chelerythrine partially inhibited the NFA effect. Therefore, in addition to direct channel block, NFA also inhibits gCl indirectly by promoting PKC activation. CONCLUSIONS AND IMPLICATIONS These cellular effects of NFA on skeletal muscle demonstrate that it is possible to modify CLC-1 and consequently gCl directly by interacting with channel proteins and indirectly by interfering with the calcium-dependent regulation of the channel. The effect of NFA on mitochondrial calcium stores suggests that NSAIDs, widely used drugs, could have potentially dangerous side-effects.
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Affiliation(s)
- A Liantonio
- Unità di Farmacologia, Dipartimento Farmacobiologico, Facoltà di Farmacia, Università di Bari, Bari, Italy
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140
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Radley HG, De Luca A, Lynch GS, Grounds MD. Duchenne muscular dystrophy: focus on pharmaceutical and nutritional interventions. Int J Biochem Cell Biol 2006; 39:469-77. [PMID: 17137828 DOI: 10.1016/j.biocel.2006.09.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2006] [Revised: 09/08/2006] [Accepted: 09/29/2006] [Indexed: 11/16/2022]
Abstract
Duchenne muscular dystrophy is a lethal X-linked muscle disease resulting from a defect in the muscle membrane protein dystrophin. The absence of dystrophin leads to muscle membrane fragility, muscle death (necrosis) and eventual replacement of skeletal muscle by fat and fibrous connective tissue. Extensive muscle wasting and respiratory failure results in premature death often by the early 20s. This short review evaluates drug and nutritional interventions designed to reduce the severity of muscular dystrophy, while awaiting the outcome of research into therapies to correct the fundamental gene defect. Combinations of dietary supplementation with amino-acids such as creatine, specific anti-inflammatory drugs and perhaps drugs that target ion channels might have immediate realistic clinical benefits although rigorous research is required to determine optimal combinations of such interventions.
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Affiliation(s)
- H G Radley
- School of Anatomy and Human Biology, University of Western Australia, Crawley, Australia
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141
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Rolland JF, De Luca A, Burdi R, Andreetta F, Confalonieri P, Conte Camerino D. Overactivity of exercise-sensitive cation channels and their impaired modulation by IGF-1 in mdx native muscle fibers: beneficial effect of pentoxifylline. Neurobiol Dis 2006; 24:466-74. [PMID: 17010631 DOI: 10.1016/j.nbd.2006.08.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 08/01/2006] [Accepted: 08/14/2006] [Indexed: 11/17/2022] Open
Abstract
Cell-attached patch-clamp recordings on native striated myofibers from adult dystrophic mdx mice revealed a higher occurrence and open probability compared to non-dystrophic wild-type myofibers of a 30 pS voltage-insensitive Ca2+-permeable channel, inhibited by Gd3+, streptomycin and ruthenium red. Myofibers from in vivo exercised animals had higher channel occurrence and/or open probability. Insulin-like growth factor 1 (3.3 nM) induced and/or enhanced channel activity, via PI3 kinase, in wild-type but not in mdx myofibers. Interestingly, in both genotypes the current was silenced by db-cAMP or pentoxifylline, a phosphodiesterase inhibitor. The channel activity/occurrence in pentoxifylline-treated exercised mdx (50 mg/kg/day i.p. for 4-8 weeks) overlapped that of exercised wild-type mice. Thus, a growth factor-sensitive current, likely due to a TRP channel, is activated in vivo by exercise in native striated fibers; its deregulation in the absence of dystrophin may contribute to Ca2+ homeostasis alteration. The possibility to pharmacologically counteract abnormal channel activity discloses important therapeutic application.
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Affiliation(s)
- Jean-François Rolland
- Unit of Pharmacology, Department of Pharmacobiology, Faculty of Pharmacy, University of Bari, Bari, Italy
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142
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Hodgetts S, Radley H, Davies M, Grounds MD. Reduced necrosis of dystrophic muscle by depletion of host neutrophils, or blocking TNFalpha function with Etanercept in mdx mice. Neuromuscul Disord 2006; 16:591-602. [PMID: 16935507 DOI: 10.1016/j.nmd.2006.06.011] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Revised: 06/22/2006] [Accepted: 06/29/2006] [Indexed: 10/24/2022]
Abstract
Necrosis of skeletal muscle fibres in the lethal childhood myopathy Duchenne Muscular Dystrophy results from deficiency of the cell membrane associated protein, dystrophin. We test the hypothesis in dystrophin-deficient mice, that the initial sarcolemmal breakdown resulting from dystrophin deficiency is exacerbated by inflammatory cells, specifically neutrophils, and that cytokines, specifically Tumour Necrosis Factor alpha (TNFalpha), contribute to myofibre necrosis. Antibody depletion of host neutrophils resulted in a delayed and significantly reduced amount of skeletal muscle breakdown in young dystrophic mdx mice. A more striking and prolonged protective effect was seen after pharmacological blockade of TNFalpha bioactivity using Etanercept. The extent of exercise induced myofibre necrosis in adult mdx mice after voluntarily wheel exercise was also reduced after Etanercept administration. These data show a clear role for neutrophils and TNFalpha in necrosis of dystrophic mdx muscle in vivo. Etanercept is a highly specific anti-inflammatory drug, widely used clinically, and potential application to muscular dystrophies is suggested by this reduced breakdown of mdx skeletal muscle.
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MESH Headings
- Animals
- Antibodies/immunology
- Disease Models, Animal
- Down-Regulation/drug effects
- Down-Regulation/immunology
- Dystrophin/deficiency
- Etanercept
- Female
- Immunoglobulin G/pharmacology
- Immunoglobulin G/therapeutic use
- Immunosuppressive Agents/pharmacology
- Immunosuppressive Agents/therapeutic use
- Inflammation/drug therapy
- Inflammation/physiopathology
- Inflammation/prevention & control
- Mice
- Mice, Inbred mdx
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/immunology
- Muscle, Skeletal/physiopathology
- Muscular Dystrophy, Duchenne/drug therapy
- Muscular Dystrophy, Duchenne/immunology
- Muscular Dystrophy, Duchenne/physiopathology
- Necrosis/drug therapy
- Necrosis/physiopathology
- Necrosis/prevention & control
- Neutrophils/drug effects
- Neutrophils/immunology
- Physical Conditioning, Animal/adverse effects
- Receptors, Tumor Necrosis Factor/therapeutic use
- Treatment Outcome
- Tumor Necrosis Factor-alpha/antagonists & inhibitors
- Tumor Necrosis Factor-alpha/metabolism
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Affiliation(s)
- Stuart Hodgetts
- School of Anatomy and Human Biology, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
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143
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Uozumi Y, Ito T, Hoshino Y, Mohri T, Maeda M, Takahashi K, Fujio Y, Azuma J. Myogenic differentiation induces taurine transporter in association with taurine-mediated cytoprotection in skeletal muscles. Biochem J 2006; 394:699-706. [PMID: 16318624 PMCID: PMC1383720 DOI: 10.1042/bj20051303] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Skeletal muscle homoeostasis is maintained by a variety of cytoprotective mechanisms. Since ablation of the TauT (taurine transporter) gene results in susceptibility to exercise-induced muscle weakness in vivo, it has been suggested that TauT is essential for skeletal muscle function. However, the regulatory mechanisms of TauT expression remain to be elucidated. In the present study, we demonstrated that TauT was up-regulated during myogenesis in C2C12 cells. Treatment with bFGF (basic fibroblast growth factor), which inhibited muscle differentiation, abrogated myogenic induction of TauT. The promoter activities of TauT were up-regulated during muscle differentiation in C2C12 cells. Database analyses identified an MEF2 (myocyte enhancer binding factor 2) consensus sequence at -844 in the rat TauT gene. Truncation of the promoter region containing the MEF2 site significantly reduced the promoter activity, demonstrating the functional importance of the MEF2 site. Electrophoretic mobility-shift assays confirmed that MEF2 bound to the MEF2 consensus sequence and that DNA-protein complex levels were increased during differentiation. Promoter analyses using mutated promoter-reporter plasmids demonstrated that this site was functional. Importantly, transfection with a MyoD expression vector markedly enhanced TauT promoter activity in the (non-myogenic) 10T1/2 cells. Moreover, co-transfection with an MEF2 expression vector augmented MyoD-induced TauT promoter activity, suggesting that MEF2 is required for full activation of TauT expression. Finally, we examined the effects of taurine on myotube atrophy to clarify the biological significance of the up-regulation of TauT, and demonstrated that taurine attenuated muscle atrophy induced by dexamethasone. TauT expression is regulated under the control of the myogenic programme, and we propose that this is the mechanism for taurine-mediated resistance to muscle atrophy.
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Affiliation(s)
- Yoriko Uozumi
- Laboratory of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, 1–6 Yamada-oka Suita, 565-0871, Japan
| | - Takashi Ito
- Laboratory of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, 1–6 Yamada-oka Suita, 565-0871, Japan
| | - Yuki Hoshino
- Laboratory of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, 1–6 Yamada-oka Suita, 565-0871, Japan
| | - Tomomi Mohri
- Laboratory of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, 1–6 Yamada-oka Suita, 565-0871, Japan
| | - Makiko Maeda
- Laboratory of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, 1–6 Yamada-oka Suita, 565-0871, Japan
| | - Kyoko Takahashi
- Laboratory of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, 1–6 Yamada-oka Suita, 565-0871, Japan
| | - Yasushi Fujio
- Laboratory of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, 1–6 Yamada-oka Suita, 565-0871, Japan
| | - Junichi Azuma
- Laboratory of Clinical Pharmacology and Pharmacogenomics, Graduate School of Pharmaceutical Sciences, Osaka University, 1–6 Yamada-oka Suita, 565-0871, Japan
- To whom correspondence should be addressed (email )
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144
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Radley HG, Grounds MD. Cromolyn administration (to block mast cell degranulation) reduces necrosis of dystrophic muscle in mdx mice. Neurobiol Dis 2006; 23:387-97. [PMID: 16798005 DOI: 10.1016/j.nbd.2006.03.016] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 03/22/2006] [Accepted: 03/31/2006] [Indexed: 11/19/2022] Open
Abstract
Duchenne muscular dystrophy is a lethal muscle wasting disorder, resulting from mutations in the gene encoding for the skeletal muscle protein dystrophin. The absence of functional dystrophin leaves the muscle membrane vulnerable to damage during contraction. Damage initially occurs as 'tears' in the membrane, this damage can be exacerbated by the inflammatory response leading to myofibre necrosis rather than repair. Mast cells resident within skeletal muscle represent an immediate source of pro-inflammatory cytokines. We hypothesise that blockade of mast cell degranulation would reduce the extent of myofibre necrosis in the mdx mouse. Daily cromolyn injections were performed on young and exercised adult mdx mice and histological analysis confirmed that mast cell degranulation contributes to myofibre necrosis. This research identified high biological variation between individual mdx mice in the severity of the dystrophic pathology, and supported a relationship between extent of muscle damage in adult mdx mice and their individual enthusiasm for voluntary wheel running.
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Affiliation(s)
- Hannah G Radley
- School of Anatomy and Human Biology, M309,University of Western Australia, Crawley, Australia
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145
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Basset O, Boittin FX, Cognard C, Constantin B, Ruegg U. Bcl-2 overexpression prevents calcium overload and subsequent apoptosis in dystrophic myotubes. Biochem J 2006; 395:267-76. [PMID: 16393138 PMCID: PMC1422769 DOI: 10.1042/bj20051265] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a lethal disease caused by the lack of the cytoskeletal protein dystrophin. Altered calcium homoeostasis and increased calcium concentrations in dystrophic fibres may be responsible for the degeneration of muscle occurring in DMD. In the present study, we used subsarcolemmal- and mitochondrial-targeted aequorin to study the effect of the antiapoptotic Bcl-2 protein overexpression on carbachol-induced near-plasma membrane and mitochondrial calcium responses in myotubes derived from control C57 and dystrophic (mdx) mice. We show that Bcl-2 overexpression decreases subsarcolemmal and mitochondrial calcium overload that occurs during activation of nicotinic acetylcholine receptors in dystrophic myotubes. Moreover, our results suggest that overexpressed Bcl-2 protein may prevent near-plasma membrane and mitochondrial calcium overload by inhibiting IP3Rs (inositol 1,4,5-trisphosphate receptors), which we have shown previously to be involved in abnormal calcium homoeostasis in dystrophic myotubes. Most likely as a consequence, the inhibition of IP3R function by Bcl-2 also inhibits calcium-dependent apoptosis in these cells.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Calcium/metabolism
- Calcium Channels
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Cells, Cultured
- Gene Expression
- Inositol 1,4,5-Trisphosphate/pharmacology
- Inositol 1,4,5-Trisphosphate Receptors
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Mitochondria/metabolism
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/pathology
- Muscular Dystrophy, Animal/metabolism
- Muscular Dystrophy, Animal/pathology
- Protein Transport
- Proto-Oncogene Proteins c-bcl-2/genetics
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Staurosporine/pharmacology
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Affiliation(s)
- Olivier Basset
- *Laboratory of Pharmacology, Geneva-Lausanne School of Pharmaceutical Sciences, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Geneva 4, Switzerland
| | - François-Xavier Boittin
- *Laboratory of Pharmacology, Geneva-Lausanne School of Pharmaceutical Sciences, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Geneva 4, Switzerland
| | - Christian Cognard
- †Institut de Physiologie et Biologie Cellulaire, CNRS-UMR6187, University of Poitiers, 86022 Poitiers Cedex, France
| | - Bruno Constantin
- †Institut de Physiologie et Biologie Cellulaire, CNRS-UMR6187, University of Poitiers, 86022 Poitiers Cedex, France
| | - Urs T. Ruegg
- *Laboratory of Pharmacology, Geneva-Lausanne School of Pharmaceutical Sciences, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Geneva 4, Switzerland
- To whom correspondence should be addressed (email )
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146
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Burdi R, Didonna MP, Pignol B, Nico B, Mangieri D, Rolland JF, Camerino C, Zallone A, Ferro P, Andreetta F, Confalonieri P, De Luca A. First evaluation of the potential effectiveness in muscular dystrophy of a novel chimeric compound, BN 82270, acting as calpain-inhibitor and anti-oxidant. Neuromuscul Disord 2006; 16:237-48. [PMID: 16542837 DOI: 10.1016/j.nmd.2006.01.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2005] [Revised: 12/22/2005] [Accepted: 01/16/2006] [Indexed: 11/19/2022]
Abstract
BN 82270 is a membrane-permeable prodrug of a chimeric compound (BN 82204) dually acting as calpain inhibitor and anti-oxidant. Acute in vivo injection of dystrophic mdx mice (30 mg/kg, s.c.) fully counteracted calpain overactivity in diaphragm. A chronic 4-6 weeks administration significantly prevented in vivo the fore limb force drop occurring in mdx mice exercised on treadmill. Ex vivo electrophysiological recordings showed that BN 82270 treatment contrasted the decrease in chloride channel function (gCl) in diaphragm, an index of spontaneous degeneration, while it was less effective on both exercise-impaired gCl and calcium-dependent mechanical threshold of the hind limb extensor digitorum longus (EDL) muscle fibres. The BN 82270 treated mdx mice showed a marked reduction of plasma creatine kinase and of the pro-fibrotic cytokine TGF-beta1 in both hind limb muscles and diaphragm; however, the histopathological profile of gastrocnemious muscle was poorly ameliorated. In hind limb muscles of treated mice, the active form was detected by HPLC in the low therapeutic concentration range. In vitro exposure to 100 microM BN 82270 led to higher active form in diaphragm than in EDL muscle. This is the first demonstration that this class of chimeric compounds, dually targeting pathology-related events, exerts beneficial effects in muscular dystrophy. The drug/prodrug system may require posology adjustment to produce wider beneficial effects on all muscle types.
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Affiliation(s)
- Rosa Burdi
- Unit of Pharmacology, Department of Pharmacobiology, Faculty of Pharmacy, University of Bari, Bari, Italy
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147
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Timmons JA, Larsson O, Jansson E, Fischer H, Gustafsson T, Greenhaff PL, Ridden J, Rachman J, Peyrard-Janvid M, Wahlestedt C, Sundberg CJ. Human muscle gene expression responses to endurance training provide a novel perspective on Duchenne muscular dystrophy. FASEB J 2005; 19:750-60. [PMID: 15857889 DOI: 10.1096/fj.04-1980com] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Global gene expression profiling is used to generate novel insight into a variety of disease states. Such studies yield a bewildering number of data points, making it a challenge to validate which genes specifically contribute to a disease phenotype. Aerobic exercise training represents a plausible model for identification of molecular mechanisms that cause metabolic-related changes in human skeletal muscle. We carried out the first transcriptome-wide characterization of human skeletal muscle responses to 6 wk of supervised aerobic exercise training in 8 sedentary volunteers. Biopsy samples before and after training allowed us to identify approximately 470 differentially regulated genes using the Affymetrix U95 platform (80 individual hybridization steps). Gene ontology analysis indicated that extracellular matrix and calcium binding gene families were most up-regulated after training. An electronic reanalysis of a Duchenne muscular dystrophy (DMD) transcript expression dataset allowed us to identify approximately 90 genes modulated in a nearly identical fashion to that observed in the endurance exercise dataset. Trophoblast noncoding RNA, an interfering RNA species, was the singular exception-being up-regulated by exercise and down-regulated in DMD. The common overlap between gene expression datasets may be explained by enhanced alpha7beta1 integrin signaling, and specific genes in this signaling pathway were up-regulated in both datasets. In contrast to these common features, OXPHOS gene expression is subdued in DMD yet elevated by exercise, indicating that more than one major mechanism must exist in human skeletal muscle to sense activity and therefore regulate gene expression. Exercise training modulated diabetes-related genes, suggesting our dataset may contain additional and novel gene expression changes relevant for the anti-diabetic properties of exercise. In conclusion, gene expression profiling after endurance exercise training identified a range of processes responsible for the physiological remodeling of human skeletal muscle tissue, many of which were similarly regulated in DMD. Furthermore, our analysis demonstrates that numerous genes previously suggested as being important for the DMD disease phenotype may principally reflect compensatory integrin signaling.
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Affiliation(s)
- James A Timmons
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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148
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Brimah K, Ehrhardt J, Mouly V, Butler-Browne GS, Partridge TA, Morgan JE. Human muscle precursor cell regeneration in the mouse host is enhanced by growth factors. Hum Gene Ther 2005; 15:1109-24. [PMID: 15610611 DOI: 10.1089/hum.2004.15.1109] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aim of this study was to optimize human muscle formation in vivo from implanted human muscle precursor cells. We transplanted donor muscle precursor cells (MPCs) prepared from postnatal or fetal human muscle into immunodeficient host mice and showed that irradiation of host muscle significantly enhanced muscle formation by donor cells. The amount of donor muscle formed in cryodamaged host muscle was increased by exposure of donor cells to growth factors before their implantation into injured host muscle. Insulin-like growth factor type I (IGF-I) significantly increased the amount of muscle formed by postnatal human muscle cells, but not by fetal human MPCs. However, treatment of fetal muscle cells with IGF-I, in combination with basic fibroblast growth factor and plasmin, significantly increased the amount of donor muscle formed. In vivo, human MPCs formed mosaic human-mouse muscle fibers, in which each human myonucleus was associated with a zone of human sarcolemmal protein spectrin.
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Affiliation(s)
- K Brimah
- Muscle Cell Biology Group, MRC Clinical Sciences Centre, Imperial College, London W12 ONN, United Kingdom
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149
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De Luca A, Nico B, Liantonio A, Didonna MP, Fraysse B, Pierno S, Burdi R, Mangieri D, Rolland JF, Camerino C, Zallone A, Confalonieri P, Andreetta F, Arnoldi E, Courdier-Fruh I, Magyar JP, Frigeri A, Pisoni M, Svelto M, Conte Camerino D. A multidisciplinary evaluation of the effectiveness of cyclosporine a in dystrophic mdx mice. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 166:477-89. [PMID: 15681831 PMCID: PMC1602333 DOI: 10.1016/s0002-9440(10)62270-5] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Chronic inflammation is a secondary reaction of Duchenne muscular dystrophy and may contribute to disease progression. To examine whether immunosuppressant therapies could benefit dystrophic patients, we analyzed the effects of cyclosporine A (CsA) on a dystrophic mouse model. Mdx mice were treated with 10 mg/kg of CsA for 4 to 8 weeks throughout a period of exercise on treadmill, a protocol that worsens the dystrophic condition. The CsA treatment fully prevented the 60% drop of forelimb strength induced by exercise. A significant amelioration (P < 0.05) was observed in histological profile of CsA-treated gastrocnemius muscle with reductions of nonmuscle area (20%), centronucleated fibers (12%), and degenerating area (50%) compared to untreated exercised mdx mice. Consequently, the percentage of normal fibers increased from 26 to 35% in CsA-treated mice. Decreases in creatine kinase and markers of fibrosis were also observed. By electrophysiological recordings ex vivo, we found that CsA counteracted the decrease in chloride conductance (gCl), a functional index of degeneration in diaphragm and extensor digitorum longus muscle fibers. However, electrophysiology and fura-2 calcium imaging did not show any amelioration of calcium homeostasis in extensor digitorum longus muscle fibers. No significant effect was observed on utrophin levels in diaphragm muscle. Our data show that the CsA treatment significantly normalized many functional, histological, and biochemical endpoints by acting on events that are independent or downstream of calcium homeostasis. The beneficial effect of CsA may involve different targets, reinforcing the usefulness of immunosuppressant drugs in muscular dystrophy.
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Affiliation(s)
- Annamaria De Luca
- Sezione di Farmacologia, Dipartimento Farmacobiologico, Facoltà di Farmacia, Università degli Studi di Bari, Via Orabona 4, Campus, 70125 Bari, Italy.
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150
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Fisher I, Abraham D, Bouri K, Hoffmann EP, Hoffman EP, Muntoni F, Morgan J. Prednisolone‐induced changes in dystrophic skeletal muscle. FASEB J 2005; 19:834-6. [PMID: 15734791 DOI: 10.1096/fj.04-2511fje] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although glucocorticoids delay the progression of Duchenne muscular dystrophy (DMD) their mechanism of action is unknown. Skeletal muscle gene expression profiles of mdx mice, an animal model of DMD, treated with prednisolone were compared with control mice at 1 and 6 wk. Of the 89 early differentially regulated genes and ESTs, delta-sarcoglycan, myosin Va, FK506-binding protein 51 (FKBP51), the potassium channel regulator potassium inwardly-rectifying channel Isk-like (IRK2) and ADAM 10 were overexpressed, whereas growth hormone-releasing hormone receptor (GHRHR) and Homer-2 were underexpressed. The 58 late differentially overexpressed genes included kallikreins (13, 16, and 26), FKBP51, PI3K alpha regulatory subunit, and IGFBP6, while underexpressed genes included NeuroD and nicotinic cholinergic receptor gamma. At both time points, overexpression of a cohort of genes relating to metabolism and proteolysis was apparent, alongside the differential expression of genes relating to calcium metabolism. Treatment did not increase muscle regeneration, reduce the number of infiltrating macrophages, or alter utrophin expression or localization. However, in the treated mdx soleus muscle, the percentage of slow fibers was significantly lower compared with untreated controls after 6 wk of treatment. These results show that glucocorticoids confer their benefit to dystrophic muscle in a complex fashion, culminating in a switch to a more normal muscle fiber type.
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MESH Headings
- Amyloid Precursor Protein Secretases
- Animals
- Aspartic Acid Endopeptidases
- Blotting, Western
- Calcineurin/analysis
- Carrier Proteins/genetics
- Endopeptidases/genetics
- Gene Expression/drug effects
- Gene Expression Profiling
- Gene Expression Regulation/drug effects
- Homer Scaffolding Proteins
- Male
- Mice
- Mice, Inbred mdx
- Muscle Fibers, Slow-Twitch/drug effects
- Muscle Fibers, Slow-Twitch/pathology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscular Dystrophy, Animal/metabolism
- Muscular Dystrophy, Animal/pathology
- NFATC Transcription Factors/analysis
- Necrosis
- Oligonucleotide Array Sequence Analysis
- Potassium Channels, Inwardly Rectifying/genetics
- Prednisolone/pharmacology
- Receptors, Neuropeptide/genetics
- Receptors, Pituitary Hormone-Regulating Hormone/genetics
- Tacrolimus Binding Proteins/genetics
- Utrophin/genetics
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Affiliation(s)
- Ivan Fisher
- Muscle Cell Biology Group, MRC Clinical Sciences Centre, Imperial College, London, UK
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