A Multidisciplinary Evaluation of the Effectiveness of Cyclosporine A in Dystrophic Mdx Mice

PubMed Central

De Luca, Annamaria; Nico, Beatrice; Liantonio, Antonella; Paola Didonna, Maria; Fraysse, Bodvael; Pierno, Sabata; Burdi, Rosa; Mangieri, Domenica; Rolland, Jean-François; Camerino, Claudia; Zallone, Alberta; Confalonieri, Paolo; Andreetta, Francesca; Arnoldi, Elisa; Courdier-Fruh, Isabelle; Magyar, Josef P.; Frigeri, Antonio; Pisoni, Michela; Svelto, Maria; Conte-Camerino, Diana

2005-01-01

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. PMID:15681831

Contribution of Dysferlin Deficiency to Skeletal Muscle Pathology in Asymptomatic and Severe Dystroglycanopathy Models: Generation of a New Model for Fukuyama Congenital Muscular Dystrophy

PubMed Central

Kanagawa, Motoi; Lu, Zhongpeng; Ito, Chiyomi; Matsuda, Chie; Miyake, Katsuya; Toda, Tatsushi

2014-01-01

Defects in dystroglycan glycosylation are associated with a group of muscular dystrophies, termed dystroglycanopathies, that include Fukuyama congenital muscular dystrophy (FCMD). It is widely believed that abnormal glycosylation of dystroglycan leads to disease-causing membrane fragility. We previously generated knock-in mice carrying a founder retrotransposal insertion in fukutin, the gene responsible for FCMD, but these mice did not develop muscular dystrophy, which hindered exploring therapeutic strategies. We hypothesized that dysferlin functions may contribute to muscle cell viability in the knock-in mice; however, pathological interactions between glycosylation abnormalities and dysferlin defects remain unexplored. To investigate contributions of dysferlin deficiency to the pathology of dystroglycanopathy, we have crossed dysferlin-deficient dysferlin sjl/sjl mice to the fukutin-knock-in fukutin Hp/− and Large-deficient Large myd/myd mice, which are phenotypically distinct models of dystroglycanopathy. The fukutin Hp/− mice do not show a dystrophic phenotype; however, (dysferlin sjl/sjl: fukutin Hp/−) mice showed a deteriorated phenotype compared with (dysferlin sjl/sjl: fukutin Hp/+) mice. These data indicate that the absence of functional dysferlin in the asymptomatic fukutin Hp/− mice triggers disease manifestation and aggravates the dystrophic phenotype. A series of pathological analyses using double mutant mice for Large and dysferlin indicate that the protective effects of dysferlin appear diminished when the dystrophic pathology is severe and also may depend on the amount of dysferlin proteins. Together, our results show that dysferlin exerts protective effects on the fukutin Hp/− FCMD mouse model, and the (dysferlin sjl/sjl: fukutin Hp/−) mice will be useful as a novel model for a recently proposed antisense oligonucleotide therapy for FCMD. PMID:25198651

Hsp72 preserves muscle function and slows progression of severe muscular dystrophy.

PubMed

Gehrig, Stefan M; van der Poel, Chris; Sayer, Timothy A; Schertzer, Jonathan D; Henstridge, Darren C; Church, Jarrod E; Lamon, Severine; Russell, Aaron P; Davies, Kay E; Febbraio, Mark A; Lynch, Gordon S

2012-04-04

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder caused by mutations in the dystrophin gene that result in the absence of the membrane-stabilizing protein dystrophin. Dystrophin-deficient muscle fibres are fragile and susceptible to an influx of Ca(2+), which activates inflammatory and muscle degenerative pathways. At present there is no cure for DMD, and existing therapies are ineffective. Here we show that increasing the expression of intramuscular heat shock protein 72 (Hsp72) preserves muscle strength and ameliorates the dystrophic pathology in two mouse models of muscular dystrophy. Treatment with BGP-15 (a pharmacological inducer of Hsp72 currently in clinical trials for diabetes) improved muscle architecture, strength and contractile function in severely affected diaphragm muscles in mdx dystrophic mice. In dko mice, a phenocopy of DMD that results in severe spinal curvature (kyphosis), muscle weakness and premature death, BGP-15 decreased kyphosis, improved the dystrophic pathophysiology in limb and diaphragm muscles and extended lifespan. We found that the sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA, the main protein responsible for the removal of intracellular Ca(2+)) is dysfunctional in severely affected muscles of mdx and dko mice, and that Hsp72 interacts with SERCA to preserve its function under conditions of stress, ultimately contributing to the decreased muscle degeneration seen with Hsp72 upregulation. Treatment with BGP-15 similarly increased SERCA activity in dystrophic skeletal muscles. Our results provide evidence that increasing the expression of Hsp72 in muscle (through the administration of BGP-15) has significant therapeutic potential for DMD and related conditions, either as a self-contained therapy or as an adjuvant with other potential treatments, including gene, cell and pharmacological therapies.

Treatment with the cysteine precursor l-2-oxothiazolidine-4-carboxylate (OTC) implicates taurine deficiency in severity of dystropathology in mdx mice.

PubMed

Terrill, Jessica R; Boyatzis, Amber; Grounds, Miranda D; Arthur, Peter G

2013-09-01

Oxidative stress has been implicated in the pathology of the lethal skeletal muscle disease Duchenne muscular dystrophy (DMD), and various antioxidants have been investigated as a potential therapy. Recently, treatment of the mdx mouse model for DMD with the antioxidant and cysteine and glutathione (GSH) precursor n-acetylcysteine (NAC) was shown to decrease protein thiol oxidation and improve muscle pathology and ex vivo muscle strength. This study further investigates the mechanism for the benefits of NAC on dystrophic muscle by administering l-2-oxothiazolidine-4-carboxylate (OTC) which also upregulates intracellular cysteine and GSH, but does not directly function as an antioxidant. We observed that OTC, like NAC, decreases protein thiol oxidation, decreases pathology and increases strength, suggesting that the both NAC and OTC function via increasing cysteine and GSH content of dystrophic muscle. We demonstrate that mdx muscle is not deficient in either cysteine or GSH and that these are not increased by OTC treatment. However, we show that dystrophic muscle of 12 week old mdx mice is deficient in taurine, a by-product of disposal of excess cysteine, a deficiency that is ameliorated by OTC treatment. These data suggest that in dystrophic muscles, apart from the strong association of increased oxidative stress and protein thiol oxidation with dystropathology, another major issue is an insufficiency in taurine that can be corrected by increasing the availability of cysteine. This study provides new insight into the molecular mechanism underlying the benefits of NAC in muscular dystrophy and supports the use of OTC as an alternative drug for potential clinical applications to DMD. Copyright © 2013 Elsevier Ltd. All rights reserved.

Participation of Myosin Va and Pka Type I in the Regeneration of Neuromuscular Junctions

PubMed Central

Röder, Ira Verena; Strack, Siegfried; Reischl, Markus; Dahley, Oliver; Khan, Muzamil Majid; Kassel, Olivier; Zaccolo, Manuela; Rudolf, Rüdiger

2012-01-01

Background The unconventional motor protein, myosin Va, is crucial for the development of the mouse neuromuscular junction (NMJ) in the early postnatal phase. Furthermore, the cooperative action of protein kinase A (PKA) and myosin Va is essential to maintain the adult NMJ. We here assessed the involvement of myosin Va and PKA in NMJ recovery during muscle regeneration. Methodology/Principal Findings To address a putative role of myosin Va and PKA in the process of muscle regeneration, we used two experimental models the dystrophic mdx mouse and Notexin-induced muscle degeneration/regeneration. We found that in both systems myosin Va and PKA type I accumulate beneath the NMJs in a fiber maturation-dependent manner. Morphologically intact NMJs were found to express stable nicotinic acetylcholine receptors and to accumulate myosin Va and PKA type I in the subsynaptic region. Subsynaptic cAMP signaling was strongly altered in dystrophic muscle, particularly in fibers with severely subverted NMJ morphology. Conclusions/Significance Our data show a correlation between the subsynaptic accumulation of myosin Va and PKA type I on the one hand and NMJ regeneration status and morphology, AChR stability and specificity of subsynaptic cAMP handling on the other hand. This suggests an important role of myosin Va and PKA type I for the maturation of NMJs in regenerating muscle. PMID:22815846

Alterations in Notch signalling in skeletal muscles from mdx and dko dystrophic mice and patients with Duchenne muscular dystrophy.

PubMed

Church, Jarrod E; Trieu, Jennifer; Chee, Annabel; Naim, Timur; Gehrig, Stefan M; Lamon, Séverine; Angelini, Corrado; Russell, Aaron P; Lynch, Gordon S

2014-04-01

New Findings What is the central question of this study? The Notch signalling pathway plays an important role in muscle regeneration, and activation of the pathway has been shown to enhance muscle regeneration in aged mice. It is unknown whether Notch activation will have a similarly beneficial effect on muscle regeneration in the context of Duchenne muscular dystrophy (DMD). What is the main finding and its importance? Although expression of Notch signalling components is altered in both mouse models of DMD and in human DMD patients, activation of the Notch signalling pathway does not confer any functional benefit on muscles from dystrophic mice, suggesting that other signalling pathways may be more fruitful targets for manipulation in treating DMD. Abstract In Duchenne muscular dystrophy (DMD), muscle damage and impaired regeneration lead to progressive muscle wasting, weakness and premature death. The Notch signalling pathway represents a central regulator of gene expression and is critical for cellular proliferation, differentiation and apoptotic signalling during all stages of embryonic muscle development. Notch activation improves muscle regeneration in aged mice, but its potential to restore regeneration and function in muscular dystrophy is unknown. We performed a comprehensive examination of several genes involved in Notch signalling in muscles from dystrophin-deficient mdx and dko (utrophin- and dystrophin-null) mice and DMD patients. A reduction of Notch1 and Hes1 mRNA in tibialis anterior muscles of dko mice and quadriceps muscles of DMD patients and a reduction of Hes1 mRNA in the diaphragm of the mdx mice were observed, with other targets being inconsistent across species. Activation and inhibition of Notch signalling, followed by measures of muscle regeneration and function, were performed in the mouse models of DMD. Notch activation had no effect on functional regeneration in C57BL/10, mdx or dko mice. Notch inhibition significantly depressed the frequency-force relationship in regenerating muscles of C57BL/10 and mdx mice after injury, indicating reduced force at each stimulation frequency, but enhanced the frequency-force relationship in muscles from dko mice. We conclude that while Notch inhibition produces slight functional defects in dystrophic muscle, Notch activation does not significantly improve muscle regeneration in murine models of muscular dystrophy. Furthermore, the inconsistent expression of Notch targets between murine models and DMD patients suggests caution when making interspecies comparisons.

PITX2 Enhances the Regenerative Potential of Dystrophic Skeletal Muscle Stem Cells.

PubMed

Vallejo, Daniel; Hernández-Torres, Francisco; Lozano-Velasco, Estefanía; Rodriguez-Outeiriño, Lara; Carvajal, Alejandra; Creus, Carlota; Franco, Diego; Aránega, Amelia Eva

2018-04-10

Duchenne muscular dystrophy (DMD), one of the most lethal genetic disorders, involves progressive muscle degeneration resulting from the absence of DYSTROPHIN. Lack of DYSTROPHIN expression in DMD has critical consequences in muscle satellite stem cells including a reduced capacity to generate myogenic precursors. Here, we demonstrate that the c-isoform of PITX2 transcription factor modifies the myogenic potential of dystrophic-deficient satellite cells. We further show that PITX2c enhances the regenerative capability of mouse DYSTROPHIN-deficient satellite cells by increasing cell proliferation and the number of myogenic committed cells, but importantly also increasing dystrophin-positive (revertant) myofibers by regulating miR-31. These PITX2-mediated effects finally lead to improved muscle function in dystrophic (DMD/mdx) mice. Our studies reveal a critical role for PITX2 in skeletal muscle repair and may help to develop therapeutic strategies for muscular disorders. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Targeting early PKCθ-dependent T-cell infiltration of dystrophic muscle reduces disease severity in a mouse model of muscular dystrophy.

PubMed

Lozanoska-Ochser, Biliana; Benedetti, Anna; Rizzo, Giuseppe; Marrocco, Valeria; Di Maggio, Rosanna; Fiore, Piera; Bouche, Marina

2018-03-01

Chronic muscle inflammation is a critical feature of Duchenne muscular dystrophy and contributes to muscle fibre injury and disease progression. Although previous studies have implicated T cells in the development of muscle fibrosis, little is known about their role during the early stages of muscular dystrophy. Here, we show that T cells are among the first cells to infiltrate mdx mouse dystrophic muscle, prior to the onset of necrosis, suggesting an important role in early disease pathogenesis. Based on our comprehensive analysis of the kinetics of the immune response, we further identify the early pre-necrotic stage of muscular dystrophy as the relevant time frame for T-cell-based interventions. We focused on protein kinase C θ (PKCθ, encoded by Prkcq), a critical regulator of effector T-cell activation, as a potential target to inhibit T-cell activity in dystrophic muscle. Lack of PKCθ not only reduced the frequency and number of infiltrating T cells but also led to quantitative and qualitative changes in the innate immune cell infiltrate in mdx/Prkcq -/- muscle. These changes were due to the inhibition of T cells, since PKCθ was necessary for T-cell but not for myeloid cell infiltration of acutely injured muscle. Targeting T cells with a PKCθ inhibitor early in the disease process markedly diminished the size of the inflammatory cell infiltrate and resulted in reduced muscle damage. Moreover, diaphragm necrosis and fibrosis were also reduced following treatment. Overall, our findings identify the early T-cell infiltrate as a therapeutic target and highlight the potential of PKCθ inhibition as a therapeutic approach to muscular dystrophy. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Dysfunctional tubular endoplasmic reticulum constitutes a pathological feature of Alzheimer's disease.

PubMed

Sharoar, M G; Shi, Q; Ge, Y; He, W; Hu, X; Perry, G; Zhu, X; Yan, R

2016-09-01

Pathological features in Alzheimer's brains include mitochondrial dysfunction and dystrophic neurites (DNs) in areas surrounding amyloid plaques. Using a mouse model that overexpresses reticulon 3 (RTN3) and spontaneously develops age-dependent hippocampal DNs, here we report that DNs contain both RTN3 and REEPs, topologically similar proteins that can shape tubular endoplasmic reticulum (ER). Importantly, ultrastructural examinations of such DNs revealed gradual accumulation of tubular ER in axonal termini, and such abnormal tubular ER inclusion is found in areas surrounding amyloid plaques in biopsy samples from Alzheimer's disease (AD) brains. Functionally, abnormally clustered tubular ER induces enhanced mitochondrial fission in the early stages of DN formation and eventual mitochondrial degeneration at later stages. Furthermore, such DNs are abrogated when RTN3 is ablated in aging and AD mouse models. Hence, abnormally clustered tubular ER can be pathogenic in brain regions: disrupting mitochondrial integrity, inducing DNs formation and impairing cognitive function in AD and aging brains.

Early Detection of Myocardial Bioenergetic Deficits: A 9.4 Tesla Complete Non Invasive 31P MR Spectroscopy Study in Mice with Muscular Dystrophy.

PubMed

Cui, Weina; Jang, Albert; Zhang, Pengyuan; Thompson, Brian; Townsend, DeWayne; Metzger, Joseph M; Zhang, Jianyi

2015-01-01

Duchenne muscular dystrophy (DMD) is the most common fatal form of muscular dystrophy characterized by striated muscle wasting and dysfunction. Patients with DMD have a very high incidence of heart failure, which is increasingly the cause of death in DMD patients. We hypothesize that in the in vivo system, the dystrophic cardiac muscle displays bioenergetic deficits prior to any functional or structural deficits. To address this we developed a complete non invasive 31P magnetic resonance spectroscopy (31P MRS) approach to measure myocardial bioenergetics in the heart in vivo. Six control and nine mdx mice at 5 months of age were used for the study. A standard 3D -Image Selected In vivo Spectroscopy (3D-ISIS) sequence was used to provide complete gradient controlled three-dimensional localization for heart 31P MRS. These studies demonstrated dystrophic hearts have a significant reduction in PCr/ATP ratio compare to normal (1.59±0.13 vs 2.37±0.25, p<0.05). Our present study provides the direct evidence of significant cardiac bioenergetic deficits in the in vivo dystrophic mouse. These data suggest that energetic defects precede the development of significant hemodynamic or structural changes. The methods provide a clinically relevant approach to use myocardial energetics as an early marker of disease in the dystrophic heart. The new method in detecting the in vivo bioenergetics abnormality as an early non-invasive marker of emerging dystrophic cardiomyopathy is critical in management of patients with DMD, and optimized therapies aimed at slowing or reversing the cardiomyopathy.

Naproxcinod shows significant advantages over naproxen in the mdx model of Duchenne Muscular Dystrophy.

PubMed

Miglietta, Daniela; De Palma, Clara; Sciorati, Clara; Vergani, Barbara; Pisa, Viviana; Villa, Antonello; Ongini, Ennio; Clementi, Emilio

2015-08-22

In dystrophin-deficient muscles of Duchenne Muscular Dystrophy (DMD) patients and the mdx mouse model, nitric oxide (NO) signalling is impaired. Previous studies have shown that NO-donating drugs are beneficial in dystrophic mouse models. Recently, a long-term treatment (9 months) of mdx mice with naproxcinod, an NO-donating naproxen, has shown a significant improvement of the dystrophic phenotype with beneficial effects present throughout the disease progression. It remains however to be clearly dissected out which specific effects are due to the NO component compared with the anti-inflammatory activity associated with naproxen. Understanding the contribution of NO vs the anti-inflammatory effect is important, in view of the potential therapeutic perspective, and this is the final aim of this study. Five-week-old mdx mice received either naproxcinod (30 mg/kg) or the equimolar dose of naproxen (20 mg/kg) in the diet for 6 months. Control mdx mice were used as reference. Treatments (or vehicle for control groups) were administered daily in the diet. For the first 3 months the study was performed in sedentary animals, then all mice were subjected to exercise until the sixth month. Skeletal muscle force was assessed by measuring whole body tension in sedentary animals as well as in exercised mice and resistance to fatigue was measured after 3 months of running exercise. At the end of 6 months of treatment, animals were sacrificed for histological analysis and measurement of naproxen levels in blood and skeletal muscle. Naproxcinod significantly ameliorated skeletal muscle force and resistance to fatigue in sedentary as well as in exercised mice, reduced inflammatory infiltrates and fibrosis deposition in both cardiac and diaphragm muscles. Conversely, the equimolar dose of naproxen showed no effects on fibrosis and improved muscle function only in sedentary mice, while the beneficial effects in exercised mice were lost demonstrating a limited and short-term effect. In conclusion, this study shows that NO donation may have an important role, in addition to anti-inflammatory activity, in slowing down the progression of the disease in the mdx mouse model therefore positioning naproxcinod as a promising candidate for treatment of DMD.

NADPH oxidase-2 inhibition restores contractility and intracellular calcium handling and reduces arrhythmogenicity in dystrophic cardiomyopathy

PubMed Central

Gonzalez, Daniel R.; Treuer, Adriana V.; Lamirault, Guillaume; Mayo, Vera; Cao, Yenong; Dulce, Raul A.

2014-01-01

Duchenne muscular dystrophy may affect cardiac muscle, producing a dystrophic cardiomyopathy in humans and the mdx mouse. We tested the hypothesis that oxidative stress participates in disrupting calcium handling and contractility in the mdx mouse with established cardiomyopathy. We found increased expression (fivefold) of the NADPH oxidase (NOX) 2 in the mdx hearts compared with wild type, along with increased superoxide production. Next, we tested the impact of NOX2 inhibition on contractility and calcium handling in isolated cardiomyocytes. Contractility was decreased in mdx myocytes compared with wild type, and this was restored toward normal by pretreating with apocynin. In addition, the amplitude of evoked intracellular Ca2+ concentration transients that was diminished in mdx myocytes was also restored with NOX2 inhibition. Total sarcoplasmic reticulum (SR) Ca2+ content was reduced in mdx hearts and normalized by apocynin treatment. Additionally, NOX2 inhibition decreased the production of spontaneous diastolic calcium release events and decreased the SR calcium leak in mdx myocytes. In addition, nitric oxide (NO) synthase 1 (NOS-1) expression was increased eightfold in mdx hearts compared with wild type. Nevertheless, cardiac NO production was reduced. To test whether this paradox implied NOS-1 uncoupling, we treated cardiac myocytes with exogenous tetrahydrobioterin, along with the NOX inhibitor VAS2870. These agents restored NO production and phospholamban phosphorylation in mdx toward normal. Together, these results demonstrate that, in mdx hearts, NOX2 inhibition improves the SR calcium handling and contractility, partially by recoupling NOS-1. These findings reveal a new layer of nitroso-redox imbalance in dystrophic cardiomyopathy. PMID:25015966

Defects in mitochondrial localization and ATP synthesis in the mdx mouse model of Duchenne muscular dystrophy are not alleviated by PDE5 inhibition

PubMed Central

Percival, Justin M.; Siegel, Michael P.; Knowels, Gary; Marcinek, David J.

2013-01-01

Given the crucial roles for mitochondria in ATP energy supply, Ca2+ handling and cell death, mitochondrial dysfunction has long been suspected to be an important pathogenic feature in Duchenne muscular dystrophy (DMD). Despite this foresight, mitochondrial function in dystrophin-deficient muscles has remained poorly defined and unknown in vivo. Here, we used the mdx mouse model of DMD and non-invasive spectroscopy to determine the impact of dystrophin-deficiency on skeletal muscle mitochondrial localization and oxidative phosphorylation function in vivo. Mdx mitochondria exhibited significant uncoupling of oxidative phosphorylation (reduced P/O) and a reduction in maximal ATP synthesis capacity that together decreased intramuscular ATP levels. Uncoupling was not driven by increased UCP3 or ANT1 expression. Dystrophin was required to maintain subsarcolemmal mitochondria (SSM) pool density, implicating it in the spatial control of mitochondrial localization. Given that nitric oxide-cGMP pathways regulate mitochondria and that sildenafil-mediated phosphodiesterase 5 inhibition ameliorates dystrophic pathology, we tested whether sildenafil's benefits result from decreased mitochondrial dysfunction in mdx mice. Unexpectedly, sildenafil treatment did not affect mitochondrial content or oxidative phosphorylation defects in mdx mice. Rather, PDE5 inhibition decreased resting levels of ATP, phosphocreatine and myoglobin, suggesting that sildenafil improves dystrophic pathology through other mechanisms. Overall, these data indicate that dystrophin-deficiency disrupts SSM localization, promotes mitochondrial inefficiency and restricts maximal mitochondrial ATP-generating capacity. Together these defects decrease intramuscular ATP and the ability of mdx muscle mitochondria to meet ATP demand. These findings further understanding of how mitochondrial bioenergetic dysfunction contributes to disease pathogenesis in dystrophin-deficient skeletal muscle in vivo. PMID:23049075

Taurine deficiency, synthesis and transport in the mdx mouse model for Duchenne Muscular Dystrophy.

PubMed

Terrill, Jessica R; Grounds, Miranda D; Arthur, Peter G

2015-09-01

The amino acid taurine is essential for the function of skeletal muscle and administration is proposed as a treatment for Duchenne Muscular Dystrophy (DMD). Taurine homeostasis is dependent on multiple processes including absorption of taurine from food, endogenous synthesis from cysteine and reabsorption in the kidney. This study investigates the cause of reported taurine deficiency in the dystrophic mdx mouse model of DMD. Levels of metabolites (taurine, cysteine, cysteine sulfinate and hypotaurine) and proteins (taurine transporter [TauT], cysteine deoxygenase and cysteine sulfinate dehydrogenase) were quantified in juvenile control C57 and dystrophic mdx mice aged 18 days, 4 and 6 weeks. In C57 mice, taurine content was much higher in both liver and plasma at 18 days, and both cysteine and cysteine deoxygenase were increased. As taurine levels decreased in maturing C57 mice, there was increased transport (reabsorption) of taurine in the kidney and muscle. In mdx mice, taurine and cysteine levels were much lower in liver and plasma at 18 days, and in muscle cysteine was low at 18 days, whereas taurine was lower at 4: these changes were associated with perturbations in taurine transport in liver, kidney and muscle and altered metabolism in liver and kidney. These data suggest that the maintenance of adequate body taurine relies on sufficient dietary intake of taurine and cysteine availability and metabolism, as well as retention of taurine by the kidney. This research indicates dystrophin deficiency not only perturbs taurine metabolism in the muscle but also affects taurine metabolism in the liver and kidney, and supports targeting cysteine and taurine deficiency as a potential therapy for DMD. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Collagen VII deficient mice show morphologic and histologic corneal changes that phenotypically mimic human dystrophic epidermolysis bullosa of the eye.

PubMed

Chen, Vicki M; Shelke, Rajani; Nyström, Alexander; Laver, Nora; Sampson, James F; Zhiyi, Cao; Bhat, Najma; Panjwani, Noorjahan

2018-06-16

Absence of collagen VII causes blistering of the skin, eyes and many other tissues. This disease is termed dystrophic epidermolysis bullosa (DEB). Corneal fibrosis occurs in up to 41% and vision loss in up to 64% of patients. Standard treatments are supportive and there is no cure. The immune-histologic and morphologic changes in the corneas of the mouse model for this disease have not been described in the literature. Our purpose is to characterize the eyes of these mice to determine if this is an appropriate model for study of human therapeutics. Western blot analysis (WB) and immunohistochemistry (IHC) were performed to assess the relative collagen VII protein levels and its location within the cornea. Additional IHC for inflammatory and fibrotic biomarkers alpha-smooth muscle actin (α-SMA), transforming growth factor-beta (TGF-β), connective tissue growth factor (CTGF), proteinase 3, tenascin C and collagen III were performed. Clinical photographs documenting opacification of the corneas of animals of differing ages were assessed and scored independently by 2 examiners. Histology was then used to investigate morphologic changes. IHC and WB confirmed that these mice are deficient in collagen VII production at the level of the basement membrane when compared with wild-types. IHC showed anomalous deposition of collagen III throughout the stroma. Of the 5 biomarkers tested, TGF-β showed the strongest and most consistently staining. Photographs documented corneal opacities only in mice older than 10 weeks, opacities were not seen in younger animals. Histology showed multiple abnormalities, including epithelial hyperplasia, ulceration, fibrosis, edema, dysplasia, neovascularization and bullae formation. The collagen VII hypomorphic mouse shows reduced collagen VII production at the level of the corneal basement membrane. Corneal changes are similar to pathology seen in humans with this disease. The presence of anomalous stromal collagen III and TGF-β appear to be the most consistent and strongest staining biomarkers in diseased mice. This mouse appears to mimic human corneal disease. It is an appropriate model for testing of therapeutics to treat EB ocular disease. Copyright © 2018. Published by Elsevier Ltd.

Dasatinib as a treatment for Duchenne muscular dystrophy.

PubMed

Lipscomb, Leanne; Piggott, Robert W; Emmerson, Tracy; Winder, Steve J

2016-01-15

Identification of a systemically acting and universal small molecule therapy for Duchenne muscular dystrophy would be an enormous advance for this condition. Based on evidence gained from studies on mouse genetic models, we have identified tyrosine phosphorylation and degradation of β-dystroglycan as a key event in the aetiology of Duchenne muscular dystrophy. Thus, preventing tyrosine phosphorylation and degradation of β-dystroglycan presents itself as a potential therapeutic strategy. Using the dystrophic sapje zebrafish, we have investigated the use of tyrosine kinase and other inhibitors to treat the dystrophic symptoms in this model of Duchenne muscular dystrophy. Dasatinib, a potent and specific Src tyrosine kinase inhibitor, was found to decrease the levels of β-dystroglycan phosphorylation on tyrosine and to increase the relative levels of non-phosphorylated β-dystroglycan in sapje zebrafish. Furthermore, dasatinib treatment resulted in the improved physical appearance of the sapje zebrafish musculature and increased swimming ability as measured by both duration and distance of swimming of dasatinib-treated fish compared with control animals. These data suggest great promise for pharmacological agents that prevent the phosphorylation of β-dystroglycan on tyrosine and subsequent steps in the degradation pathway as therapeutic targets for the treatment of Duchenne muscular dystrophy. © The Author 2015. Published by Oxford University Press.

Deficiency of merosin in dystrophic dy mouse homologue of congenital muscular dystrophy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sunada, Y.; Campbell, K.P.; Bernier, S.M.

1994-09-01

Merosin (laminin M chain) is the predominant laminin isoform in the basal lamina of striated muscle and peripheral nerve and is a native ligand for {alpha}-dystroglycan, a novel laminin receptor. Merosin is linked to the subsarcolemmal actin cytoskeleton via the dystrophin-glycoprotein complex (DGC), which plays an important role for maintenance of normal muscle function. We have mapped the mouse merosin gene, Lamm, to the region containing the dystrophia muscularis (dy) locus on chromosome 10. This suggested the possibility that a mutation in the merosin gene could be responsible for the dy mouse, an animal model for autosomal recessive muscular dystrophy,more » and prompted us to test this hypothesis. We analyzed the status of merosin expression in dy mouse by immunofluorescence and immunoblotting. In dy mouse skeletal and cardiac muscle and peripheral nerve, merosin was reduced greater than 90% as compared to control mice. However, the expression of laminin B1/B2 chains and collagen type IV was smaller to that in control mice. These findings strongly suggest that merosin deficiency may be the primary defect in the dy mouse. Furthermore, we have identified two patients afflicted with congenital muscular dystrophy with merosin deficiency, providing the basis for future studies of molecular pathogenesis and gene therapy.« less

Impaired JIP3-dependent axonal lysosome transport promotes amyloid plaque pathology

PubMed Central

Gowrishankar, Swetha; Wu, Yumei

2017-01-01

Lysosomes robustly accumulate within axonal swellings at Alzheimer’s disease (AD) amyloid plaques. However, the underlying mechanisms and disease relevance of such lysosome accumulations are not well understood. Motivated by these problems, we identified JNK-interacting protein 3 (JIP3) as an important regulator of axonal lysosome transport and maturation. JIP3 knockout mouse neuron primary cultures accumulate lysosomes within focal axonal swellings that resemble the dystrophic axons at amyloid plaques. These swellings contain high levels of amyloid precursor protein processing enzymes (BACE1 and presenilin 2) and are accompanied by elevated Aβ peptide levels. The in vivo importance of the JIP3-dependent regulation of axonal lysosomes was revealed by the worsening of the amyloid plaque pathology arising from JIP3 haploinsufficiency in a mouse model of AD. These results establish the critical role of JIP3-dependent axonal lysosome transport in regulating amyloidogenic amyloid precursor protein processing and support a model wherein Aβ production is amplified by plaque-induced axonal lysosome transport defects. PMID:28784610

Donor Satellite Cell Engraftment is Significantly Augmented When the Host Niche is Preserved and Endogenous Satellite Cells are Incapacitated

PubMed Central

Boldrin, Luisa; Neal, Alice; Zammit, Peter S; Muntoni, Francesco; Morgan, Jennifer E

2012-01-01

Stem cell transplantation is already in clinical practice for certain genetic diseases and is a promising therapy for dystrophic muscle. We used the mdx mouse model of Duchenne muscular dystrophy to investigate the effect of the host satellite cell niche on the contribution of donor muscle stem cells (satellite cells) to muscle regeneration. We found that incapacitation of the host satellite cells and preservation of the muscle niche promote donor satellite cell contribution to muscle regeneration and functional reconstitution of the satellite cell compartment. But, if the host niche is not promptly refilled, or is filled by competent host satellite cells, it becomes nonfunctional and donor engraftment is negligible. Application of this regimen to aged host muscles also promotes efficient regeneration from aged donor satellite cells. In contrast, if the niche is destroyed, yet host satellite cells remain proliferation-competent, donor-derived engraftment is trivial. Thus preservation of the satellite cell niche, concomitant with functional impairment of the majority of satellite cells within dystrophic human muscles, may improve the efficiency of stem cell therapy. Stem Cells2012;30:1971–1984 PMID:22730231

Antisense Oligonucleotide-mediated Exon Skipping as a Systemic Therapeutic Approach for Recessive Dystrophic Epidermolysis Bullosa.

PubMed

Bremer, Jeroen; Bornert, Olivier; Nyström, Alexander; Gostynski, Antoni; Jonkman, Marcel F; Aartsma-Rus, Annemieke; van den Akker, Peter C; Pasmooij, Anna Mg

2016-10-18

The "generalized severe" form of recessive dystrophic epidermolysis bullosa (RDEB-gen sev) is caused by bi-allelic null mutations in COL7A1, encoding type VII collagen. The absence of type VII collagen leads to blistering of the skin and mucous membranes upon the slightest trauma. Because most patients carry exonic point mutations or small insertions/deletions, most exons of COL7A1 are in-frame, and low levels of type VII collagen already drastically improve the disease phenotype, this gene seems a perfect candidate for antisense oligonucleotide (AON)-mediated exon skipping. In this study, we examined the feasibility of AON-mediated exon skipping in vitro in primary cultured keratinocytes and fibroblasts, and systemically in vivo using a human skin-graft mouse model. We show that treatment with AONs designed against exon 105 leads to in-frame exon 105 skipping at the RNA level and restores type VII collagen protein production in vitro. Moreover, we demonstrate that systemic delivery in vivo induces de novo expression of type VII collagen in skin grafts generated from patient cells. Our data demonstrate strong proof-of-concept for AON-mediated exon skipping as a systemic therapeutic strategy for RDEB.

Similar efficacy from specific and non-specific mineralocorticoid receptor antagonist treatment of muscular dystrophy mice.

PubMed

Lowe, Jeovanna; Floyd, Kyle T; Rastogi, Neha; Schultz, Eric J; Chadwick, Jessica A; Swager, Sarah A; Zins, Jonathan G; Kadakia, Feni K; Smart, Suzanne; Gomez-Sanchez, Elise P; Gomez-Sanchez, Celso E; Raman, Subha V; Janssen, Paul M L; Rafael-Fortney, Jill A

2016-01-01

Combined treatment with an angiotensin-converting enzyme inhibitor and a mineralocorticoid receptor (MR) antagonist improved cardiac and skeletal muscle function and pathology in a mouse model of Duchenne muscular dystrophy. MR is present in limb and respiratory skeletal muscles and functions as a steroid hormone receptor. The goals of the current study were to compare the efficacy of the specific MR antagonist eplerenone with the non-specific MR antagonist spironolactone, both in combination with the angiotensin-converting enzyme inhibitor lisinopril. Three groups of n=18 dystrophin-deficient, utrophin-haploinsufficient male mice were given chow containing: lisinopril plus spironolactone, lisinopril plus eplerenone, or no drug, from four to 20 weeks-of-age. Eighteen C57BL/10 male mice were used as wild-type controls. In vivo measurements included cardiac magnetic resonance imaging, conscious electrocardiography, and grip strength. From each mouse in the study, diaphragm, extensor digitorum longus , and cardiac papillary muscle force was measured ex vivo , followed by histological quantification of muscle damage in heart, diaphragm, quadriceps, and abdominal muscles. MR protein levels were also verified in treated muscles. Treatment with specific and non-specific MR antagonists did not result in any adverse effects to dystrophic skeletal muscles or heart. Both treatments resulted in similar functional and pathological improvements across a wide array of parameters. MR protein levels were not reduced by treatment. These data suggest that spironolactone and eplerenone show similar effects in dystrophic mice and support the clinical development of MR antagonists for treating skeletal muscles in Duchenne muscular dystrophy.

Bone Marrow Cell Transfer into Fetal Circulation Can Ameliorate Genetic Skin Diseases by Providing Fibroblasts to the Skin and Inducing Immune Tolerance

PubMed Central

Chino, Takenao; Tamai, Katsuto; Yamazaki, Takehiko; Otsuru, Satoru; Kikuchi, Yasushi; Nimura, Keisuke; Endo, Masayuki; Nagai, Miki; Uitto, Jouni; Kitajima, Yasuo; Kaneda, Yasufumi

2008-01-01

Recent studies have shown that skin injury recruits bone marrow-derived fibroblasts (BMDFs) to the site of injury to accelerate tissue repair. However, whether uninjured skin can recruit BMDFs to maintain skin homeostasis remains uncertain. Here, we investigated the appearance of BMDFs in normal mouse skin after embryonic bone marrow cell transplantation (E-BMT) with green fluorescent protein-transgenic bone marrow cells (GFP-BMCs) via the vitelline vein, which traverses the uterine wall and is connected to the fetal circulation. At 12 weeks of age, mice treated with E-BMT were observed to have successful engraftment of GFP-BMCs in hematopoietic tissues accompanied by induction of immune tolerance against GFP. We then investigated BMDFs in the skin of the same mice without prior injury and found that a significant number of BMDFs, which generate matrix proteins both in vitro and in vivo, were recruited and maintained after birth. Next, we performed E-BMT in a dystrophic epidermolysis bullosa mouse model (col7a1−/−) lacking type VII collagen in the cutaneous basement membrane zone. E-BMT significantly ameliorated the severity of the dystrophic epidermolysis bullosa phenotype in neonatal mice. Type VII collagen was deposited primarily in the follicular basement membrane zone in the vicinity of the BMDFs. Thus, gene therapy using E-BMT into the fetal circulation may offer a potential treatment option to ameliorate genetic skin diseases that are characterized by fibroblast dysfunction through the introduction of immune-tolerated BMDFs. PMID:18688022

Beneficial effects of voluntary wheel running on the properties of dystrophic mouse muscle.

PubMed

Hayes, A; Williams, D A

1996-02-01

Effects of voluntary exercise on the isometric contractile, fatigue, and histochemical properties of hindlimb dystrophic (mdx and 129ReJ dy/dy) skeletal muscles were investigated. Mice were allowed free access to a voluntary running wheel at 4 wk of age for a duration of 16 (mdx) or 5 (dy/dy) wk. Running performance of mdx mice (approximately 4 km/day at 1.6 km/h) was inferior to normal mice (approximately 6.5 km/day at 2.1 km/h). However, exercise improved the force output (approximately 15%) and the fatigue resistance of both C57BL/10 and mdx soleus muscles. These changes coincided with increased proportions of smaller type I fibers and decreased proportions of larger type IIa fibers in the mdx soleus. The extensor digitorum longus of mdx, but not of normal, mice also exhibited improved resistance to fatigue and conversion towards oxidative fiber types. The dy/dy animals were capable of exercising, yet ran significantly less than normal animals (approximately 0.5 km/day). Despite this, running increased the force output of the plantaris muscle (approximately 50%). Taken together, the results showed that exercise can have beneficial effects on dystrophic skeletal muscles.

Duchenne Muscular Dystrophy Gene Therapy in the Canine Model

PubMed Central

2015-01-01

Abstract Duchenne muscular dystrophy (DMD) is an X-linked lethal muscle disease caused by dystrophin deficiency. Gene therapy has significantly improved the outcome of dystrophin-deficient mice. Yet, clinical translation has not resulted in the expected benefits in human patients. This translational gap is largely because of the insufficient modeling of DMD in mice. Specifically, mice lacking dystrophin show minimum dystrophic symptoms, and they do not respond to the gene therapy vector in the same way as human patients do. Further, the size of a mouse is hundredfolds smaller than a boy, making it impossible to scale-up gene therapy in a mouse model. None of these limitations exist in the canine DMD (cDMD) model. For this reason, cDMD dogs have been considered a highly valuable platform to test experimental DMD gene therapy. Over the last three decades, a variety of gene therapy approaches have been evaluated in cDMD dogs using a number of nonviral and viral vectors. These studies have provided critical insight for the development of an effective gene therapy protocol in human patients. This review discusses the history, current status, and future directions of the DMD gene therapy in the canine model. PMID:25710459

Four-week rapamycin treatment improves muscular dystrophy in a fukutin-deficient mouse model of dystroglycanopathy.

PubMed

Foltz, Steven J; Luan, Junna; Call, Jarrod A; Patel, Ankit; Peissig, Kristen B; Fortunato, Marisa J; Beedle, Aaron M

2016-01-01

Secondary dystroglycanopathies are a subset of muscular dystrophy caused by abnormal glycosylation of α-dystroglycan (αDG). Loss of αDG functional glycosylation prevents it from binding to laminin and other extracellular matrix receptors, causing muscular dystrophy. Mutations in a number of genes, including FKTN (fukutin), disrupt αDG glycosylation. We analyzed conditional Fktn knockout (Fktn KO) muscle for levels of mTOR signaling pathway proteins by Western blot. Two cohorts of Myf5-cre/Fktn KO mice were treated with the mammalian target of rapamycin (mTOR) inhibitor rapamycin (RAPA) for 4 weeks and evaluated for changes in functional and histopathological features. Muscle from 17- to 25-week-old fukutin-deficient mice has activated mTOR signaling. However, in tamoxifen-inducible Fktn KO mice, factors related to Akt/mTOR signaling were unchanged before the onset of dystrophic pathology, suggesting that Akt/mTOR signaling pathway abnormalities occur after the onset of disease pathology and are not causative in early dystroglycanopathy development. To determine any pharmacological benefit of targeting mTOR signaling, we administered RAPA daily for 4 weeks to Myf5/Fktn KO mice to inhibit mTORC1. RAPA treatment reduced fibrosis, inflammation, activity-induced damage, and central nucleation, and increased muscle fiber size in Myf5/Fktn KO mice compared to controls. RAPA-treated KO mice also produced significantly higher torque at the conclusion of dosing. These findings validate a misregulation of mTOR signaling in dystrophic dystroglycanopathy skeletal muscle and suggest that such signaling molecules may be relevant targets to delay and/or reduce disease burden in dystrophic patients.

Expression patterns of regulatory RNAs, including lncRNAs and tRNAs, during postnatal growth of normal and dystrophic (mdx) mouse muscles, and their response to taurine treatment.

PubMed

Butchart, Lauren C; Terrill, Jessica R; Rossetti, Giulia; White, Robert; Filipovska, Aleksandra; Grounds, Miranda D

2018-06-01

Post-natal skeletal muscle growth in mice is very rapid and involves complex changes in many cells types over the first 6 weeks of life. The acute onset of dystropathology also occurs around 3 weeks of age in the mdx mouse model of the human disease Duchenne Muscular Dystrophy (DMD). This study investigated (i) alterations in expression patterns of regulatory non-coding RNAs (ncRNAs) in vivo, including miRNAs, lncRNAs and tRNAs, during early growth of skeletal muscles in normal control C57Bl/10Scsn (C57) compared with dystrophic mdx mice from 2 to 6 weeks of postnatal age, and revealed inherent differences in vivo for levels of 3 ncRNAs between C57 and mdx muscles before the onset of dystropathology. Since the amino acid taurine has many benefits and reduces disease severity in mdx mice, this study also (ii) determined the impact of taurine treatment on these expression patterns in mdx muscles at the onset of dystropathology (3 weeks) and after several bouts of myonecrosis and regeneration (6 weeks). Taurine treatment of mdx mice only altered ncRNA levels when administered from 18 days to 6 weeks of age, but a deficiency in tRNA levels was rectified earlier in mdx skeletal muscles treated from 14 days to 3 weeks. Myogenesis in tissue culture was also used to (iii) compare ncRNA expression patterns for both strains, and (iv) the response to taurine treatment. These analyses revealed intrinsic differences in ncRNA expression patterns during myogenesis between strains, as well as increased sensitivity of mdx ncRNA levels to taurine treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Systemic delivery of NEMO binding domain/IKKγ inhibitory peptide to young mdx mice improves dystrophic skeletal muscle histopathology.

PubMed

Reay, Daniel P; Yang, Michele; Watchko, Jon F; Daood, Molly; O'Day, Terrence L; Rehman, Khaleel K; Guttridge, Denis C; Robbins, Paul D; Clemens, Paula R

2011-09-01

The activation of nuclear factor κB (NF-κB) contributes to muscle degeneration that results from dystrophin deficiency in human Duchenne muscular dystrophy (DMD) and in the mdx mouse. In dystrophic muscle, NF-κB participates in inflammation and failure of muscle regeneration. Peptides containing the NF-κB Essential Modulator (NEMO) binding domain (NBD) disrupt the IκB kinase complex, thus blocking NF-κB activation. The NBD peptide, which is linked to a protein transduction domain to achieve in vivo peptide delivery to muscle tissue, was systemically delivered to mdx mice for 4 or 7 weeks to study NF-κB activation, histological changes in hind limb and diaphragm muscle and ex vivo function of diaphragm muscle. Decreased NF-κB activation, decreased necrosis and increased regeneration were observed in hind limb and diaphragm muscle in mdx mice treated systemically with NBD peptide, as compared to control mdx mice. NBD peptide treatment resulted in improved generation of specific force and greater resistance to lengthening activations in diaphragm muscle ex vivo. Together these data support the potential of NBD peptides for the treatment of DMD by modulating dystrophic pathways in muscle that are downstream of dystrophin deficiency. Published by Elsevier Inc.

BRANCHED FIBERS FROM OLD FAST-TWITCH DYSTROPHIC MUSCLES ARE THE SITES OF TERMINAL DAMAGE IN MUSCULAR DYSTROPHY.

PubMed

Kiriaev, Leonit; Kueh, Sindy; Morley, John W; North, Kathryn N; Houweling, Peter J; Head, Stewart I

2018-02-07

A striking pathological feature of dystrophinopathies is the presence of morphologically abnormal branched skeletal muscle fibers. The deterioration of muscle contractile function in Duchenne muscular dystrophy is accompanied by both an increase in number and complexity of these branched fibers. We propose that when number and complexity of branched fibers reaches a critical threshold, "tipping point" the branches in and of themselves are the site of contraction-induced rupture. In the present study, we use the dystrophic mdx mouse and littermate controls to study the pre-diseased dystrophic fast-twitch EDL muscle at 2-3-weeks, the peak myonecrotic phase at 6-9 weeks and finally "old" at 58-112 weeks. Using a combination of isolated muscle function contractile measurements coupled with single fiber imaging and confocal microscope imaging of cleared whole muscles we identified a distinct pathophysiology; acute fiber rupture at branch nodes, which occurs in "old" fast-twitch EDL muscle approaching the end stage of the dystrophinopathy muscle disease, where the EDL muscles are entirely composed of complexed branched fibers. This evidence supports our concept of "tipping point" where the number and extent of fiber branching reaches a level where the branching itself terminally compromises muscle function, irrespective of the absence of dystrophin.

Enalapril treatment discloses an early role of angiotensin II in inflammation- and oxidative stress-related muscle damage in dystrophic mdx mice☆

PubMed Central

Cozzoli, Anna; Nico, Beatrice; Sblendorio, Valeriana Teresa; Capogrosso, Roberta Francesca; Dinardo, Maria Maddalena; Longo, Vito; Gagliardi, Sara; Montagnani, Monica; De Luca, Annamaria

2011-01-01

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. PMID:21689754

Immunoproteasome in animal models of Duchenne muscular dystrophy.

PubMed

Chen, Chiao-Nan Joyce; Graber, Ted G; Bratten, Wendy M; Ferrington, Deborah A; Thompson, LaDora V

2014-04-01

Increased proteasome activity has been implicated in the atrophy and deterioration associated with dystrophic muscles of Duchenne muscular dystrophy (DMD). While proteasome inhibitors show promise in the attenuation of muscle degeneration, proteasome inhibition-induced toxicity was a major drawback of this therapeutic strategy. Inhibitors that selectively target the proteasome subtype that is responsible for the loss in muscle mass and quality would reduce side effects and be less toxic. This study examined proteasome activity and subtype populations, along with muscle function, morphology and damage in wild-type (WT) mice and two murine models of DMD, dystrophin-deficient (MDX) and dystrophin- and utrophin-double-knockout (DKO) mice. We found that immunoproteasome content was increased in dystrophic muscles while the total proteasome content was unchanged among the three genotypes of mice. Proteasome proteolytic activity was elevated in dystrophic muscles, especially in DKO mice. These mice also exhibited more severe muscle atrophy than either WT or MDX mice. Muscle damage and regeneration, characterized by the activity of muscle creatine kinase in the blood and the percentage of central nuclei were equally increased in dystrophic mice. Accordingly, the overall muscle function was similarly reduced in both dystrophic mice compared with WT. These data demonstrated that there was transformation of standard proteasomes to immunoproteasomes in dystrophic muscles. In addition, DKO that showed greatest increase in proteasome activities also demonstrated more severe atrophy compared with MDX and WT. These results suggest a putative role for the immunoproteasome in muscle deterioration associated with DMD and provide a potential target for therapeutic intervention.

Novel and optimized strategies for inducing fibrosis in vivo: focus on Duchenne Muscular Dystrophy

PubMed Central

2014-01-01

Background Fibrosis, an excessive collagen accumulation, results in scar formation, impairing function of vital organs and tissues. Fibrosis is a hallmark of muscular dystrophies, including the lethal Duchenne muscular dystrophy (DMD), which remains incurable. Substitution of muscle by fibrotic tissue also complicates gene/cell therapies for DMD. Yet, no optimal models to study muscle fibrosis are available. In the widely used mdx mouse model for DMD, extensive fibrosis develops in the diaphragm only at advanced adulthood, and at about two years of age in the ‘easy-to-access’ limb muscles, thus precluding fibrosis research and the testing of novel therapies. Methods We developed distinct experimental strategies, ranging from chronic exercise to increasing muscle damage on limb muscles of young mdx mice, by myotoxin injection, surgically induced trauma (laceration or denervation) or intramuscular delivery of profibrotic growth factors (such as TGFβ). We also extended these approaches to muscle of normal non-dystrophic mice. Results These strategies resulted in advanced and enhanced muscle fibrosis in young mdx mice, which persisted over time, and correlated with reduced muscle force, thus mimicking the severe DMD phenotype. Furthermore, increased fibrosis was also obtained by combining these procedures in muscles of normal mice, mirroring aberrant repair after severe trauma. Conclusions We have developed new and improved experimental strategies to accelerate and enhance muscle fibrosis in vivo. These strategies will allow rapidly assessing fibrosis in the easily accessible limb muscles of young mdx mice, without necessarily having to use old animals. The extension of these fibrogenic regimes to the muscle of non-dystrophic wild-type mice will allow fibrosis assessment in a wide array of pre-existing transgenic mouse lines, which in turn will facilitate understanding the mechanisms of fibrogenesis. These strategies should improve our ability to combat fibrosis-driven dystrophy progression and aberrant regeneration. PMID:25157321

PROGRESSIVE RESISTANCE VOLUNTARY WHEEL RUNNING IN THE mdx MOUSE

PubMed Central

Call, Jarrod A.; McKeehen, James N.; Novotny, Susan A.; Lowe, Dawn A.

2012-01-01

Exercise training has been minimally explored as a therapy to mitigate the loss of muscle strength for individuals with Duchenne muscular dystrophy (DMD). Voluntary wheel running is known to elicit beneficial adaptations in the mdx mouse model for DMD. The aim of this study was to examine progressive resistance wheel running in mdx mice by comprehensively testing muscle function before, during, and after a 12-week training period. Male mdx mice at ~4 weeks age were randomized into three groups: Sedentary, Free Wheel, and Resist Wheel. Muscle strength was assessed via in vivo dorsiflexion torque, grip strength, and whole body tension intermittently throughout the training period. Contractility of isolated soleus muscles was analyzed at the study’s conclusion. Both Free and Resist Wheel mice had greater grip strength (~22%) and soleus muscle specific tetanic force (26%) compared with Sedentary mice. This study demonstrates that two modalities of voluntary exercise are beneficial to dystrophic muscle and may help establish parameters for an exercise prescription for DMD. PMID:21104862

Abeta42-driven cerebral amyloidosis in transgenic mice reveals early and robust pathology.

PubMed

Radde, Rebecca; Bolmont, Tristan; Kaeser, Stephan A; Coomaraswamy, Janaky; Lindau, Dennis; Stoltze, Lars; Calhoun, Michael E; Jäggi, Fabienne; Wolburg, Hartwig; Gengler, Simon; Haass, Christian; Ghetti, Bernardino; Czech, Christian; Hölscher, Christian; Mathews, Paul M; Jucker, Mathias

2006-09-01

We have generated a novel transgenic mouse model on a C57BL/6J genetic background that coexpresses KM670/671NL mutated amyloid precursor protein and L166P mutated presenilin 1 under the control of a neuron-specific Thy1 promoter element (APPPS1 mice). Cerebral amyloidosis starts at 6-8 weeks and the ratio of human amyloid (A)beta42 to Abeta40 is 1.5 and 5 in pre-depositing and amyloid-depositing mice, respectively. Consistent with this ratio, extensive congophilic parenchymal amyloid but minimal amyloid angiopathy is observed. Amyloid-associated pathologies include dystrophic synaptic boutons, hyperphosphorylated tau-positive neuritic structures and robust gliosis, with neocortical microglia number increasing threefold from 1 to 8 months of age. Global neocortical neuron loss is not apparent up to 8 months of age, but local neuron loss in the dentate gyrus is observed. Because of the early onset of amyloid lesions, the defined genetic background of the model and the facile breeding characteristics, APPPS1 mice are well suited for studying therapeutic strategies and the pathomechanism of amyloidosis by cross-breeding to other genetically engineered mouse models.

Aβ42-driven cerebral amyloidosis in transgenic mice reveals early and robust pathology

PubMed Central

Radde, Rebecca; Bolmont, Tristan; Kaeser, Stephan A; Coomaraswamy, Janaky; Lindau, Dennis; Stoltze, Lars; Calhoun, Michael E; Jäggi, Fabienne; Wolburg, Hartwig; Gengler, Simon; Haass, Christian; Ghetti, Bernardino; Czech, Christian; Hölscher, Christian; Mathews, Paul M; Jucker, Mathias

2006-01-01

We have generated a novel transgenic mouse model on a C57BL/6J genetic background that coexpresses KM670/671NL mutated amyloid precursor protein and L166P mutated presenilin 1 under the control of a neuron-specific Thy1 promoter element (APPPS1 mice). Cerebral amyloidosis starts at 6–8 weeks and the ratio of human amyloid (A)β42 to Aβ40 is 1.5 and 5 in pre-depositing and amyloid-depositing mice, respectively. Consistent with this ratio, extensive congophilic parenchymal amyloid but minimal amyloid angiopathy is observed. Amyloid-associated pathologies include dystrophic synaptic boutons, hyperphosphorylated tau-positive neuritic structures and robust gliosis, with neocortical microglia number increasing threefold from 1 to 8 months of age. Global neocortical neuron loss is not apparent up to 8 months of age, but local neuron loss in the dentate gyrus is observed. Because of the early onset of amyloid lesions, the defined genetic background of the model and the facile breeding characteristics, APPPS1 mice are well suited for studying therapeutic strategies and the pathomechanism of amyloidosis by cross-breeding to other genetically engineered mouse models. PMID:16906128

Caspase-12 ablation preserves muscle function in the mdx mouse

PubMed Central

Moorwood, Catherine; Barton, Elisabeth R.

2014-01-01

Duchenne muscular dystrophy (DMD) is a devastating muscle wasting disease caused by mutations in dystrophin. Several downstream consequences of dystrophin deficiency are triggers of endoplasmic reticulum (ER) stress, including loss of calcium homeostasis, hypoxia and oxidative stress. During ER stress, misfolded proteins accumulate in the ER lumen and the unfolded protein response (UPR) is triggered, leading to adaptation or apoptosis. We hypothesized that ER stress is heightened in dystrophic muscles and contributes to the pathology of DMD. We observed increases in the ER stress markers BiP and cleaved caspase-4 in DMD patient biopsies, compared with controls, and an increase in multiple UPR pathways in muscles of the dystrophin-deficient mdx mouse. We then crossed mdx mice with mice null for caspase-12, the murine equivalent of human caspase-4, which are resistant to ER stress. We found that deleting caspase-12 preserved mdx muscle function, resulting in a 75% recovery of both specific force generation and resistance to eccentric contractions. The compensatory hypertrophy normally found in mdx muscles was normalized in the absence of caspase-12; this was found to be due to decreased fibre sizes, and not to a fibre type shift or a decrease in fibrosis. Fibre central nucleation was not significantly altered in the absence of caspase-12, but muscle fibre degeneration found in the mdx mouse was reduced almost to wild-type levels. In conclusion, we have identified heightened ER stress and abnormal UPR signalling as novel contributors to the dystrophic phenotype. Caspase-4 is therefore a potential therapeutic target for DMD. PMID:24879640

Morpholino oligomer-mediated exon skipping averts the onset of dystrophic pathology in the mdx mouse.

PubMed

Fletcher, Sue; Honeyman, Kaite; Fall, Abbie M; Harding, Penny L; Johnsen, Russell D; Steinhaus, Joshua P; Moulton, Hong M; Iversen, Patrick L; Wilton, Stephen D

2007-09-01

Duchenne and Becker muscular dystrophies are allelic disorders arising from mutations in the dystrophin gene. Duchenne muscular dystrophy is characterized by an absence of functional protein, whereas Becker muscular dystrophy, commonly caused by in-frame deletions, shows synthesis of partially functional protein. Anti-sense oligonucleotides can induce specific exon removal during processing of the dystrophin primary transcript, while maintaining or restoring the reading frame, and thereby overcome protein-truncating mutations. The mdx mouse has a non-sense mutation in exon 23 of the dystrophin gene that precludes functional dystrophin production, and this model has been used in the development of treatment strategies for dystrophinopathies. A phosphorodiamidate morpholino oligomer (PMO) has previously been shown to exclude exon 23 from the dystrophin gene transcript and induce dystrophin expression in the mdxmouse, in vivo and in vitro. In this report, a cell-penetrating peptide (CPP)-conjugated oligomer targeted to the mouse dystrophin exon 23 donor splice site was administered to mdxmice by intraperitoneal injection. We demonstrate dystrophin expression and near-normal muscle architecture in all muscles examined, except for cardiac muscle. The CPP greatly enhanced uptake of the PMO, resulting in widespread dystrophin expression.

Serum Osteopontin as a Novel Biomarker for Muscle Regeneration in Duchenne Muscular Dystrophy.

PubMed

Kuraoka, Mutsuki; Kimura, En; Nagata, Tetsuya; Okada, Takashi; Aoki, Yoshitsugu; Tachimori, Hisateru; Yonemoto, Naohiro; Imamura, Michihiro; Takeda, Shin'ichi

2016-05-01

Duchenne muscular dystrophy is a lethal X-linked muscle disorder. We have already reported that osteopontin (OPN), an inflammatory cytokine and myogenic factor, is expressed in the early dystrophic phase in canine X-linked muscular dystrophy in Japan, a dystrophic dog model. To further explore the possibility of OPN as a new biomarker for disease activity in Duchenne muscular dystrophy, we monitored serum OPN levels in dystrophic and wild-type dogs at different ages and compared the levels to other serum markers, such as serum creatine kinase, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1. Serum OPN levels in the dystrophic dogs were significantly elevated compared with those in wild-type dogs before and 1 hour after a cesarean section birth and at the age of 3 months. The serum OPN level was significantly correlated with the phenotypic severity of dystrophic dogs at the period corresponding to the onset of muscle weakness, whereas other serum markers including creatine kinase were not. Immunohistologically, OPN was up-regulated in infiltrating macrophages and developmental myosin heavy chain-positive regenerating muscle fibers in the dystrophic dogs, whereas serum OPN was highly elevated. OPN expression was also observed during the synergic muscle regeneration process induced by cardiotoxin injection. In conclusion, OPN is a promising biomarker for muscle regeneration in dystrophic dogs and can be applicable to boys with Duchenne muscular dystrophy. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Cone function studied with flicker electroretinogram during progressive retinal degeneration in RCS rats.

PubMed

Pinilla, I; Lund, R D; Sauvé, Y

2005-01-01

The Royal College of Surgeons (RCS) rat has a primary defect in retinal pigment epithelial cells that leads to the progressive loss of photoreceptors and central visual responsiveness. While most rods are lost by 90 days of age (P90), cones degenerate more slowly, and can be detected anatomically up to 2 years of age, despite massive neuronal death and retinal remodelling. To examine how this progressive degenerative process impacts on cone function, we recorded the electroretingram to white light flashes (1.37 log cd s m(-2)) presented at frequencies ranging from 3 to 50 Hz, under light adapted conditions (29.8 cd m(-2)). Pigmented dystrophic and congenic non-dystrophic RCS rats aged from 18 to 300 days were studied. In all responsive animals at all ages, maximal amplitudes were obtained at 3 Hz. In both non-dystrophic and dystrophic rats, there was an increase from P18 to P21 in response amplitude and critical fusion frequency. After P21, these two parameters declined progressively with age in dystrophic rats. Other changes included prolongation in latency, which was first detected prior to the initiation of amplitude reduction. While phase shifts were also detected in dystrophic RCS rats, they appeared at later degenerative stages. The latest age at which responses could be elicited in dystrophic rats was at P200, with positive waves being replaced by negative deflections. The effect of increments in the intensity of background illumination was tested at P50 in both groups. This caused a diminution in flicker response amplitude and critical fusion frequencies in non-dystrophics, while in dystrophic animals, response amplitudes were reduced only at low frequencies and critical fusion frequencies were unaltered. In conclusion, although dystrophic RCS rats undergo a progressive decline in cone function with age, the flicker responsiveness at P21 is comparable to that of non-dystrophic congenic rats, suggesting normal developmental maturation of the cone system in this animal model of retinal degeneration. Flicker responses can be recorded up to P200, at which point the retina has undergone severe regressive and reactive changes in its connectivity patterns. The fact that responses at this age consist of solely negative deflections might be a reflection of the highly pathological state of the retina.

Novel adeno-associated viral vector delivering the utrophin gene regulator jazz counteracts dystrophic pathology in mdx mice.

PubMed

Strimpakos, Georgios; Corbi, Nicoletta; Pisani, Cinzia; Di Certo, Maria Grazia; Onori, Annalisa; Luvisetto, Siro; Severini, Cinzia; Gabanella, Francesca; Monaco, Lucia; Mattei, Elisabetta; Passananti, Claudio

2014-09-01

Over-expression of the dystrophin-related gene utrophin represents a promising therapeutic strategy for Duchenne muscular dystrophy (DMD). The strategy is based on the ability of utrophin to functionally replace defective dystrophin. We developed the artificial zinc finger transcription factor "Jazz" that up-regulates both the human and mouse utrophin promoter. We observed a significant recovery of muscle strength in dystrophic Jazz-transgenic mdx mice. Here we demonstrate the efficacy of an experimental gene therapy based on the systemic delivery of Jazz gene in mdx mice by adeno-associated virus (AAV). AAV serotype 8 was chosen on the basis of its high affinity for skeletal muscle. Muscle-specific expression of the therapeutic Jazz gene was enhanced by adding the muscle α-actin promoter to the AAV vector (mAAV). Injection of mAAV8-Jazz viral preparations into mdx mice resulted in muscle-specific Jazz expression coupled with up-regulation of the utrophin gene. We show a significant recovery from the dystrophic phenotype in mAAV8-Jazz-treated mdx mice. Histological and physiological analysis revealed a reduction of fiber necrosis and inflammatory cell infiltration associated with functional recovery in muscle contractile force. The combination of ZF-ATF technology with the AAV delivery can open a new avenue to obtain a therapeutic strategy for treatment of DMD. © 2014 Wiley Periodicals, Inc.

A Reduction in Selenoprotein S Amplifies the Inflammatory Profile of Fast-Twitch Skeletal Muscle in the mdx Dystrophic Mouse.

PubMed

Wright, Craig Robert; Allsopp, Giselle Larissa; Addinsall, Alex Bernard; McRae, Natasha Lee; Andrikopoulos, Sofianos; Stupka, Nicole

2017-01-01

Excessive inflammation is a hallmark of muscle myopathies, including Duchenne muscular dystrophy (DMD). There is interest in characterising novel genes that regulate inflammation due to their potential to modify disease progression. Gene polymorphisms in Selenoprotein S ( Seps1 ) are associated with elevated proinflammatory cytokines, and in vitro SEPS1 is protective against inflammatory stress. Given that SEPS1 is highly expressed in skeletal muscle, we investigated whether the genetic reduction of Seps1 exacerbated inflammation in the mdx mouse. F1 male mdx mice with a heterozygous Seps1 deletion ( mdx : Seps1 -/+ ) were generated. The mdx:Seps1 -/+ mice had a 50% reduction in SEPS1 protein expression in hindlimb muscles. In the extensor digitorum longus (EDL) muscles, mRNA expression of monocyte chemoattractant protein 1 ( Mcp-1 ) ( P = 0.034), macrophage marker F4/80 ( P = 0.030), and transforming growth factor-β1 ( Tgf-β1 ) ( P = 0.056) were increased in mdx:Seps1 -/+ mice. This was associated with a reduction in muscle fibre size; however, ex vivo EDL muscle strength and endurance were unaltered. In dystrophic slow twitch soleus muscles, SEPS1 reduction had no effect on the inflammatory profile nor function. In conclusion, the genetic reduction of Seps1 appears to specifically exacerbate the inflammatory profile of fast-twitch muscle fibres, which are typically more vulnerable to degeneration in dystrophy.

Novel mutations in human and mouse SCN4A implicate AMPK in myotonia and periodic paralysis

PubMed Central

Corrochano, Silvia; Männikkö, Roope; Joyce, Peter I.; McGoldrick, Philip; Lassi, Glenda; Raja Rayan, Dipa L.; Blanco, Gonzalo; Quinn, Colin; Liavas, Andrianos; Lionikas, Arimantas; Amior, Neta; Dick, James; Healy, Estelle G.; Stewart, Michelle; Carter, Sarah; Hutchinson, Marie; Bentley, Liz; Fratta, Pietro; Cortese, Andrea; Cox, Roger; Brown, Steve D. M.; Tucci, Valter; Wackerhage, Henning; Amato, Anthony A.; Greensmith, Linda; Koltzenburg, Martin; Hanna, Michael G.; Acevedo-Arozena, Abraham

2014-01-01

Mutations in the skeletal muscle channel (SCN4A), encoding the Nav1.4 voltage-gated sodium channel, are causative of a variety of muscle channelopathies, including non-dystrophic myotonias and periodic paralysis. The effects of many of these mutations on channel function have been characterized both in vitro and in vivo. However, little is known about the consequences of SCN4A mutations downstream from their impact on the electrophysiology of the Nav1.4 channel. Here we report the discovery of a novel SCN4A mutation (c.1762A>G; p.I588V) in a patient with myotonia and periodic paralysis, located within the S1 segment of the second domain of the Nav1.4 channel. Using N-ethyl-N-nitrosourea mutagenesis, we generated and characterized a mouse model (named draggen), carrying the equivalent point mutation (c.1744A>G; p.I582V) to that found in the patient with periodic paralysis and myotonia. Draggen mice have myotonia and suffer from intermittent hind-limb immobility attacks. In-depth characterization of draggen mice uncovered novel systemic metabolic abnormalities in Scn4a mouse models and provided novel insights into disease mechanisms. We discovered metabolic alterations leading to lean mice, as well as abnormal AMP-activated protein kinase activation, which were associated with the immobility attacks and may provide a novel potential therapeutic target. PMID:25348630

N-Acetylcysteine treatment of dystrophic mdx mice results in protein thiol modifications and inhibition of exercise induced myofibre necrosis.

PubMed

Terrill, Jessica R; Radley-Crabb, Hannah G; Grounds, Miranda D; Arthur, Peter G

2012-05-01

Oxidative stress is implicated as a factor that increases necrosis of skeletal muscles in Duchenne Muscular Dystrophy (DMD) and the dystrophic mdx mouse. Consequently, drugs that minimize oxidative stress are potential treatments for muscular dystrophy. This study examined the in vivo benefits to mdx mice of an antioxidant treatment with the cysteine precursor N-acetylcysteine (NAC), administered in drinking water. NAC was completely effective in preventing treadmill exercise-induced myofibre necrosis (assessed histologically) and the increased blood creatine kinase levels (a measure of sarcolemma leakiness) following exercise were significantly lower in the NAC treated mice. While NAC had no effect on malondialdehyde level or protein carbonylation (two indicators of irreversible oxidative damage), treatment with NAC for one week significantly decreased the oxidation of glutathione and protein thiols, and enhanced muscle protein thiol content. These data provide in vivo evidence for protective benefits of NAC treatment on dystropathology, potentially via protein thiol modifications. Copyright © 2011 Elsevier B.V. All rights reserved.

Bcl-2 expression during the development and degeneration of RCS rat retinae.

PubMed

Sharma, R K

2001-12-14

In various hereditary retinal degenerations, including that in Royal College of Surgeons (RCS) rats, the photoreceptors ultimately die by apoptosis. Bcl-2 is one of the genes, which regulates apoptosis and is thought to promote survival of cells. This study has investigated the developmental expression of Bcl-2 in RCS rat, which is a well-studied animal model for hereditary retinal degeneration. An antibody against Bcl-2 was used for its immunohistochemical localization in dystrophic RCS rat retinae from postnatal (PN) days 4, 7, 13, 35, 45, 70, 202 and 14 months. Results were compared with Bcl-2 localization in congenic non-dystrophic rats from PN 4, 7, 13, 44, 202 and 14 months. Bcl-2 immunoreactivity in non-dystrophic retinae was already present in PN 4 retinae in the nerve fiber layer (presumably in the endfeet of immature Müller cells) and in the proximal parts of certain radially aligned neuroepithelial cells/immature Müller cell radial processes. With increasing age the immunoreactivity in relatively more mature Müller cell radial processes spread distally towards the outer retina and between PN 13 and 44 it reached the adult distribution. No cell bodies in the ganglion cell layer were found to be immunoreactive. Expression of Bcl-2 immunoreactivity in dystrophic RCS rat retinae closely resembled that of non-dystrophic retinae. No immunoreactivity was seen in photoreceptors or retinal pigment epithelium in dystrophic or non-dystrophic retinae. In conclusion, Bcl-2 expression is not altered, either in terms of its chronology or the cell type expressing it, during retinal degeneration in RCS rats.

Eosinophilia of dystrophin-deficient muscle is promoted by perforin-mediated cytotoxicity by T cell effectors

NASA Technical Reports Server (NTRS)

Cai, B.; Spencer, M. J.; Nakamura, G.; Tseng-Ong, L.; Tidball, J. G.

2000-01-01

Previous investigations have shown that cytotoxic T lymphocytes (CTLs) contribute to muscle pathology in the dystrophin-null mutant mouse (mdx) model of Duchenne muscular dystrophy through perforin-dependent and perforin-independent mechanisms. We have assessed whether the CTL-mediated pathology includes the promotion of eosinophilia in dystrophic muscle, and thereby provides a secondary mechanism through which CTLs contribute to muscular dystrophy. Quantitative immunohistochemistry confirmed that eosinophilia is a component of the mdx dystrophy. In addition, electron microscopic observations show that eosinophils traverse the basement membrane of mdx muscle fibers and display sites of close apposition of eosinophil and muscle membranes. The close membrane apposition is characterized by impingement of eosinophilic rods of major basic protein into the muscle cell membrane. Transfer of mdx splenocytes and mdx muscle extracts to irradiated C57 mice by intraperitoneal injection resulted in muscle eosinophilia in the recipient mice. Double-mutant mice lacking dystrophin and perforin showed less eosinophilia than was displayed by mdx mice that expressed perforin. Finally, administration of prednisolone, which has been shown previously to reduce the concentration of CTLs in dystrophic muscle, produced a significant reduction in eosinophilia. These findings indicate that eosinophilia is a component of the mdx pathology that is promoted by perforin-dependent cytotoxicity of effector T cells. However, some eosinophilia of mdx muscle is independent of perforin-mediated processes.

Novel inhibitor candidates of TRPV2 prevent damage of dystrophic myocytes and ameliorate against dilated cardiomyopathy in a hamster model.

PubMed

Iwata, Yuko; Katayama, Yoshimi; Okuno, Yasushi; Wakabayashi, Shigeo

2018-03-06

Transient receptor potential cation channel, subfamily V, member 2 (TRPV2) is a principal candidate for abnormal Ca 2+ -entry pathways, which is a potential target for therapy of muscular dystrophy and cardiomyopathy. Here, an in silico drug screening and the following cell-based screening to measure the TRPV2 activation were carried out in HEK293 cells expressing TRPV2 using lead compounds (tranilast or SKF96365) and off-patent drug stocks. We identified 4 chemical compounds containing amino-benzoyl groups and 1 compound (lumin) containing an ethylquinolinium group as candidate TRPV2 inhibitors. Three of these compounds inhibited Ca 2+ entry through both mouse and human TRPV2, with IC 50 of less than 10 μM, but had no apparent effect on other members of TRP family such as TRPV1 and TRPC1. Particularly, lumin inhibited agonist-induced TRPV2 channel activity at a low dose. These compounds inhibited abnormally increased Ca 2+ influx and prevented stretch-induced skeletal muscle damage in cultured myocytes from dystrophic hamsters (J2N-k). Further, they ameliorated cardiac dysfunction, and prevented disease progression in vivo in the same J2N-k hamsters developing dilated cardiomyopathy as well as muscular dystrophy. The identified compounds described here are available as experimental tools and represent potential treatments for patients with cardiomyopathy and muscular dystrophy.

Novel inhibitor candidates of TRPV2 prevent damage of dystrophic myocytes and ameliorate against dilated cardiomyopathy in a hamster model

PubMed Central

Iwata, Yuko; Katayama, Yoshimi; Okuno, Yasushi; Wakabayashi, Shigeo

2018-01-01

Transient receptor potential cation channel, subfamily V, member 2 (TRPV2) is a principal candidate for abnormal Ca2+-entry pathways, which is a potential target for therapy of muscular dystrophy and cardiomyopathy. Here, an in silico drug screening and the following cell-based screening to measure the TRPV2 activation were carried out in HEK293 cells expressing TRPV2 using lead compounds (tranilast or SKF96365) and off-patent drug stocks. We identified 4 chemical compounds containing amino-benzoyl groups and 1 compound (lumin) containing an ethylquinolinium group as candidate TRPV2 inhibitors. Three of these compounds inhibited Ca2+ entry through both mouse and human TRPV2, with IC50 of less than 10 μM, but had no apparent effect on other members of TRP family such as TRPV1 and TRPC1. Particularly, lumin inhibited agonist-induced TRPV2 channel activity at a low dose. These compounds inhibited abnormally increased Ca2+ influx and prevented stretch-induced skeletal muscle damage in cultured myocytes from dystrophic hamsters (J2N-k). Further, they ameliorated cardiac dysfunction, and prevented disease progression in vivo in the same J2N-k hamsters developing dilated cardiomyopathy as well as muscular dystrophy. The identified compounds described here are available as experimental tools and represent potential treatments for patients with cardiomyopathy and muscular dystrophy. PMID:29581825

Mouse Regenerating Myofibers Detected as False-Positive Donor Myofibers with Anti-Human Spectrin

PubMed Central

Rozkalne, Anete; Adkin, Carl; Meng, Jinhong; Lapan, Ariya; Morgan, Jennifer E.

2014-01-01

Abstract Stem cell transplantation is being tested as a potential therapy for a number of diseases. Stem cells isolated directly from tissue specimens or generated via reprogramming of differentiated cells require rigorous testing for both safety and efficacy in preclinical models. The availability of mice with immune-deficient background that carry additional mutations in specific genes facilitates testing the efficacy of cell transplantation in disease models. The muscular dystrophies are a heterogeneous group of disorders, of which Duchenne muscular dystrophy is the most severe and common type. Cell-based therapy for muscular dystrophy has been under investigation for several decades, with a wide selection of cell types being studied, including tissue-specific stem cells and reprogrammed stem cells. Several immune-deficient mouse models of muscular dystrophy have been generated, in which human cells obtained from various sources are injected to assess their preclinical potential. After transplantation, the presence of engrafted human cells is detected via immunofluorescence staining, using antibodies that recognize human, but not mouse, proteins. Here we show that one antibody specific to human spectrin, which is commonly used to evaluate the efficacy of transplanted human cells in mouse muscle, detects myofibers in muscles of NOD/Rag1nullmdx5cv, NOD/LtSz-scid IL2Rγnull mice, or mdx nude mice, irrespective of whether they were injected with human cells. These “reactive” clusters are regenerating myofibers, which are normally present in dystrophic tissue and the spectrin antibody is likely recognizing utrophin, which contains spectrin-like repeats. Therefore, caution should be used in interpreting data based on detection of single human-specific proteins, and evaluation of human stem cell engraftment should be performed using multiple human-specific labeling strategies. PMID:24152287

Translational Studies of GALGT2 Gene Therapy for Duchenne Muscular Dystrophy

DTIC Science & Technology

2014-10-01

myofibers has been demonstrated to protect both wild type and dystrophic muscles from injury and to inhibit the development of muscular dystrophy in...dose for functional muscle correction after rAAVrh74.MCK.GALGT2 treatment in mdx mouse muscle . The second thing we have learned is that the MHCK7...post- treatment showed very low levels of sustained muscle transduction, however, co-injection of rAAVrh74.MHCK7.GALGT2 with an equivalent dose of

Long-Term Therapy With Omega-3 Ameliorates Myonecrosis and Benefits Skeletal Muscle Regeneration in Mdx Mice.

PubMed

Apolinário, Leticia Montanholi; De Carvalho, Samara Camaçari; Santo Neto, Humberto; Marques, Maria Julia

2015-09-01

In Duchenne muscle dystrophy (DMD) and in the mdx mouse model of DMD, a lack of dystrophin leads to myonecrosis and cardiorespiratory failure. Several lines of evidence suggest a detrimental role of the inflammatory process in the dystrophic process. Previously, we demonstrated that short-term therapy with eicosapentaenoic acid (EPA), at early stages of disease, ameliorated dystrophy progression in the mdx mouse. In the present study, we evaluated the effects of a long-term therapy with omega-3 later in dystrophy progression. Three-month-old mdx mice received omega-3 (300 mg/kg) or vehicle by gavage for 5 months. The quadriceps and diaphragm muscles were removed and processed for histopathology and Western blot. Long-term therapy with omega-3 increased the regulatory protein MyoD and muscle regeneration and reduced markers of inflammation (TNF-α and NF-kB) in both muscles studied. The present study supports the long-term use of omega-3 at later stages of dystrophy as a promising option to be investigated in DMD clinical trials. © 2015 Wiley Periodicals, Inc.

Expression of the Murine Duchenne Muscular Dystrophy Gene in Muscle and Brain

NASA Astrophysics Data System (ADS)

Chamberlain, Jeffrey S.; Pearlman, Joel A.; Muzny, Donna M.; Gibbs, Richard A.; Ranier, Joel E.; Reeves, Alice A.; Caskey, C. Thomas

1988-03-01

Complementary DNA clones were isolated that represent the 5' terminal 2.5 kilobases of the murine Duchenne muscular dystrophy (Dmd) messenger RNA (mRNA). Mouse Dmd mRNA was detectable in skeletal and cardiac muscle and at a level approximately 90 percent lower in brain. Dmd mRNA is also present, but at much lower than normal levels, in both the muscle and brain of three different strains of dystrophic mdx mice. The identification of Dmd mRNA in brain raises the possibility of a relation between human Duchenne muscular dystrophy (DMD) gene expression and the mental retardation found in some DMD males. These results also provide evidence that the mdx mutations are allelic variants of mouse Dmd gene mutations.

Muscle function recovery in golden retriever muscular dystrophy after AAV1-U7 exon skipping.

PubMed

Vulin, Adeline; Barthélémy, Inès; Goyenvalle, Aurélie; Thibaud, Jean-Laurent; Beley, Cyriaque; Griffith, Graziella; Benchaouir, Rachid; le Hir, Maëva; Unterfinger, Yves; Lorain, Stéphanie; Dreyfus, Patrick; Voit, Thomas; Carlier, Pierre; Blot, Stéphane; Garcia, Luis

2012-11-01

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder resulting from lesions of the gene encoding dystrophin. These usually consist of large genomic deletions, the extents of which are not correlated with the severity of the phenotype. Out-of-frame deletions give rise to dystrophin deficiency and severe DMD phenotypes, while internal deletions that produce in-frame mRNAs encoding truncated proteins can lead to a milder myopathy known as Becker muscular dystrophy (BMD). Widespread restoration of dystrophin expression via adeno-associated virus (AAV)-mediated exon skipping has been successfully demonstrated in the mdx mouse model and in cardiac muscle after percutaneous transendocardial delivery in the golden retriever muscular dystrophy dog (GRMD) model. Here, a set of optimized U7snRNAs carrying antisense sequences designed to rescue dystrophin were delivered into GRMD skeletal muscles by AAV1 gene transfer using intramuscular injection or forelimb perfusion. We show sustained correction of the dystrophic phenotype in extended muscle areas and partial recovery of muscle strength. Muscle architecture was improved and fibers displayed the hallmarks of mature and functional units. A 5-year follow-up ruled out immune rejection drawbacks but showed a progressive decline in the number of corrected muscle fibers, likely due to the persistence of a mild dystrophic process such as occurs in BMD phenotypes. Although AAV-mediated exon skipping was shown safe and efficient to rescue a truncated dystrophin, it appears that recurrent treatments would be required to maintain therapeutic benefit ahead of the progression of the disease.

Novel Adeno-Associated Viral Vector Delivering the Utrophin Gene Regulator Jazz Counteracts Dystrophic Pathology in mdx Mice

PubMed Central

Strimpakos, Georgios; Corbi, Nicoletta; Pisani, Cinzia; Di Certo, Maria Grazia; Onori, Annalisa; Luvisetto, Siro; Severini, Cinzia; Gabanella, Francesca; Monaco, Lucia; Mattei, Elisabetta; Passananti, Claudio

2014-01-01

Over-expression of the dystrophin-related gene utrophin represents a promising therapeutic strategy for Duchenne muscular dystrophy (DMD). The strategy is based on the ability of utrophin to functionally replace defective dystrophin. We developed the artificial zinc finger transcription factor “Jazz” that up-regulates both the human and mouse utrophin promoter. We observed a significant recovery of muscle strength in dystrophic Jazz-transgenic mdx mice. Here we demonstrate the efficacy of an experimental gene therapy based on the systemic delivery of Jazz gene in mdx mice by adeno-associated virus (AAV). AAV serotype 8 was chosen on the basis of its high affinity for skeletal muscle. Muscle-specific expression of the therapeutic Jazz gene was enhanced by adding the muscle α-actin promoter to the AAV vector (mAAV). Injection of mAAV8-Jazz viral preparations into mdx mice resulted in muscle-specific Jazz expression coupled with up-regulation of the utrophin gene. We show a significant recovery from the dystrophic phenotype in mAAV8-Jazz-treated mdx mice. Histological and physiological analysis revealed a reduction of fiber necrosis and inflammatory cell infiltration associated with functional recovery in muscle contractile force. The combination of ZF-ATF technology with the AAV delivery can open a new avenue to obtain a therapeutic strategy for treatment of DMD. J. Cell. Physiol. 229: 1283–1291, 2014. © 2014 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc. PMID:24469912

Age-related cognitive impairment is associated with long-term neuroinflammation and oxidative stress in a mouse model of episodic systemic inflammation.

PubMed

d'Avila, Joana Costa; Siqueira, Luciana Domett; Mazeraud, Aurélien; Azevedo, Estefania Pereira; Foguel, Debora; Castro-Faria-Neto, Hugo Caire; Sharshar, Tarek; Chrétien, Fabrice; Bozza, Fernando Augusto

2018-01-30

Microglia function is essential to maintain the brain homeostasis. Evidence shows that aged microglia are primed and show exaggerated response to acute inflammatory challenge. Systemic inflammation signals to the brain inducing changes that impact cognitive function. However, the mechanisms involved in age-related cognitive decline associated to episodic systemic inflammation are not completely understood. The aim of this study was to identify neuropathological features associated to age-related cognitive decline in a mouse model of episodic systemic inflammation. Young and aged Swiss mice were injected with low doses of LPS once a week for 6 weeks to induce episodic systemic inflammation. Sickness behavior, inflammatory markers, and neuroinflammation were assessed in different phases of systemic inflammation in young and aged mice. Behavior was evaluated long term after episodic systemic inflammation by open field, forced swimming, object recognition, and water maze tests. Episodic systemic inflammation induced systemic inflammation and sickness behavior mainly in aged mice. Systemic inflammation induced depressive-like behavior in both young and aged mice. Memory and learning were significantly affected in aged mice that presented lower exploratory activity and deficits in episodic and spatial memories, compared to aged controls and to young after episodic systemic inflammation. Systemic inflammation induced acute microglia activation in young mice that returned to base levels long term after episodic systemic inflammation. Aged mice presented dystrophic microglia in the hippocampus and entorhinal cortex at basal level and did not change morphology in the acute response to SI. Regardless of their dystrophic microglia, aged mice produced higher levels of pro-inflammatory (IL-1β and IL-6) as well as pro-resolution (IL-10 and IL-4) cytokines in the brain. Also, higher levels of Nox2 expression, oxidized proteins and lower antioxidant defenses were found in the aged brains compared to the young after episodic systemic inflammation. Our data show that aged mice have increased susceptibility to episodic systemic inflammation. Aged mice that showed cognitive impairments also presented higher oxidative stress and abnormal production of cytokines in their brains. These results indicate that a neuroinflammation and oxidative stress are pathophysiological mechanisms of age-related cognitive impairments.

Functional myogenic engraftment from mouse iPS cells.

PubMed

Darabi, Radbod; Pan, Weihong; Bosnakovski, Darko; Baik, June; Kyba, Michael; Perlingeiro, Rita C R

2011-11-01

Direct reprogramming of adult fibroblasts to a pluripotent state has opened new possibilities for the generation of patient- and disease-specific stem cells. However the ability of induced pluripotent stem (iPS) cells to generate tissue that mediates functional repair has been demonstrated in very few animal models of disease to date. Here we present the proof of principle that iPS cells may be used effectively for the treatment of muscle disorders. We combine the generation of iPS cells with conditional expression of Pax7, a robust approach to derive myogenic progenitors. Transplantation of Pax7-induced iPS-derived myogenic progenitors into dystrophic mice results in extensive engraftment, which is accompanied by improved contractility of treated muscles. These findings demonstrate the myogenic regenerative potential of iPS cells and provide rationale for their future therapeutic application for muscular dystrophies.

Single Stem Cell Imaging and Analysis Reveals Telomere Length Differences in Diseased Human and Mouse Skeletal Muscles.

PubMed

Tichy, Elisia D; Sidibe, David K; Tierney, Matthew T; Stec, Michael J; Sharifi-Sanjani, Maryam; Hosalkar, Harish; Mubarak, Scott; Johnson, F Brad; Sacco, Alessandra; Mourkioti, Foteini

2017-10-10

Muscle stem cells (MuSCs) contribute to muscle regeneration following injury. In many muscle disorders, the repeated cycles of damage and repair lead to stem cell dysfunction. While telomere attrition may contribute to aberrant stem cell functions, methods to accurately measure telomere length in stem cells from skeletal muscles have not been demonstrated. Here, we have optimized and validated such a method, named MuQ-FISH, for analyzing telomere length in MuSCs from either mice or humans. Our analysis showed no differences in telomere length between young and aged MuSCs from uninjured wild-type mice, but MuSCs isolated from young dystrophic mice exhibited significantly shortened telomeres. In corroboration, we demonstrated that telomere attrition is present in human dystrophic MuSCs, which underscores its importance in diseased regenerative failure. The robust technique described herein provides analysis at a single-cell resolution and may be utilized for other cell types, especially rare populations of cells. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Epidermolysis Bullosa Acquisita: Autoimmunity to Anchoring Fibril Collagen

PubMed Central

Chen, Mei; Kim, Gene H.; Prakash, Lori; Woodley, David T.

2012-01-01

Epidermolysis bullosa acquisita (EBA) is a rare and acquired autoimmune subepidermal bullous disease of the skin and mucosa. EBA includes various distinct clinical manifestations resembling Bullous Pemphigus, Brunsting-Perry pemphigoid, or cicatricial pemphigoid. These patients have autoantibodies against type VII collagen, an integral component of anchoring fibrils, which are responsible for attaching the dermis to the epidermis. Destruction or perturbation of the normally functioning anchoring fibrils clinically results in skin fragility, blisters, erosions, scars, milia and nail loss, all features reminiscent of genetic dystrophic epidermolysis bullosa. These anti-type VII collagen antibodies are “pathogenic” because when injected into a mouse, the mouse develops an EBA-like blistering disease. Currently treatment is often unsatisfactory, however some success has been achieved with colchichine, dapsone, photopheresis, plasmaphresis, infliximab, rituximab and IVIG. PMID:21955050

Inflammation occurs early during the Abeta deposition process in TgCRND8 mice.

PubMed

Dudal, Sherri; Krzywkowski, Pascale; Paquette, Julie; Morissette, Céline; Lacombe, Diane; Tremblay, Patrick; Gervais, Francine

2004-08-01

Alzheimer's disease (AD) is characterized by a progressive cognitive decline leading to dementia and involves the deposition of amyloid-beta (Abeta) peptides into senile plaques. Other neuropathological features that accompany progression of the disease include a decrease in synaptic density, neurofibrillary tangles, dystrophic neurites, inflammation, and neuronal cell loss. In this study, we report the early kinetics of brain amyloid deposition and its associated inflammation in an early onset transgenic mouse model of AD (TgCRND8) harboring the human amyloid precursor protein gene with the Indiana and Swedish mutations. Both diffuse and compact plaques were detected as early as 9-10 weeks of age. Abeta-immunoreactive (Abeta-IR) plaques (4G8-positive) appeared first in the neocortex and amygdala, then in the hippocampal formation, and lastly in the thalamus. Compact plaques (ThioS-positive) with an amyloid core were observed as early as diffuse plaques were detected, but in lower numbers. Amyloid deposition increased progressively with age. The formation of plaques was concurrent with the appearance of activated microglial cells and shortly followed by the clustering of activated astrocytes around plaques at 13-14 weeks of age. This TgCRND8 mouse model allows for a rapid, time-dependent study of the relationship between the fibrillogenic process and the inflammatory response during the brain amyloidogenic process.

Enhancement of Muscle T Regulatory Cells and Improvement of Muscular Dystrophic Process in mdx Mice by Blockade of Extracellular ATP/P2X Axis.

PubMed

Gazzerro, Elisabetta; Baldassari, Simona; Assereto, Stefania; Fruscione, Floriana; Pistorio, Angela; Panicucci, Chiara; Volpi, Stefano; Perruzza, Lisa; Fiorillo, Chiara; Minetti, Carlo; Traggiai, Elisabetta; Grassi, Fabio; Bruno, Claudio

2015-12-01

Infiltration of immune cells and chronic inflammation substantially affect skeletal and cardiac muscle degeneration in Duchenne muscular dystrophy. In the immune system, extracellular adenosine triphosphate (ATP) released by dying cells is sensed as a danger associated molecular pattern through P2 purinergic receptors. Specifically, the P2X7 subtype has a prominent role in regulating immune system physiology and contributes to inflammasome activation also in muscle cells. Here, we show that in vivo blockade of the extracellular ATP/P2X purinergic signaling pathway by periodate-oxidized ATP delayed the progression of the dystrophic phenotype and dampened the local inflammatory response in mdx mice, a spontaneous mouse model of dystrophin deficiency. Reduced infiltration of leukocytes and macrophages and decreased expression of IL-6 were revealed in the muscles of periodate-oxidized ATP-treated mdx mice. Concomitantly, an increase in Foxp3(+) immunosuppressive regulatory T cells was observed and correlated with enhanced myofiber regeneration. Moreover, we detected reduced concentrations of profibrotic cytokines, including transforming growth factor-β and connective tissue growth factor, in muscles of periodate-oxidized ATP-treated mdx mice. The improvement of inflammatory features was associated with increased strength and reduced necrosis, thus suggesting that pharmacologic purinergic antagonism altering the adaptive immune component in the muscle infiltrates might represent a promising therapeutic approach in Duchenne muscular dystrophy. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

The outcome of scapulothoracic fusion for painful winging of the scapula in dystrophic and non-dystrophic conditions.

PubMed

Sewell, M D; Higgs, D S; Al-Hadithy, N; Falworth, M; Bayley, I; Lambert, S M

2012-09-01

Scapulothoracic fusion (STF) for painful winging of the scapula in neuromuscular disorders can provide effective pain relief and functional improvement, but there is little information comparing outcomes between patients with dystrophic and non-dystrophic conditions. We performed a retrospective review of 42 STFs in 34 patients with dystrophic and non-dystrophic conditions using a multifilament trans-scapular, subcostal cable technique supported by a dorsal one-third semi-tubular plate. There were 16 males and 18 females with a mean age of 30 years (15 to 75) and a mean follow-up of 5.0 years (2.0 to 10.6). The mean Oxford shoulder score improved from 20 (4 to 39) to 31 (4 to 48). Patients with non-dystrophic conditions had lower overall functional scores but achieved greater improvements following STF. The mean active forward elevation increased from 59° (20° to 90°) to 97° (30° to 150°), and abduction from 51° (10° to 90°) to 83° (30° to 130°) with a greater range of movement achieved in the dystrophic group. Revision fusion for nonunion was undertaken in five patients at a mean time of 17 months (7 to 31) and two required revision for fracture. There were three pneumothoraces, two rib fractures, three pleural effusions and six nonunions. The main risk factors for nonunion were smoking, age and previous shoulder girdle surgery. STF is a salvage procedure that can provide good patient satisfaction in 82% of patients with both dystrophic and non-dystrophic pathologies, but there was a relatively high failure rate (26%) when poor outcomes were analysed. Overall function was better in patients with dystrophic conditions which correlated with better range of movement; however, patients with non-dystrophic conditions achieved greater functional improvement.

Pre-clinical evaluation of N-acetylcysteine reveals side effects in the mdx mouse model of Duchenne muscular dystrophy.

PubMed

Pinniger, Gavin J; Terrill, Jessica R; Assan, Evanna B; Grounds, Miranda D; Arthur, Peter G

2017-12-01

Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease associated with increased inflammation and oxidative stress. The antioxidant N-acetylcysteine (NAC) has been proposed as a therapeutic intervention for DMD boys, but potential adverse effects of NAC have not been widely investigated. We used young (6 weeks old) growing mdx mice to investigate the capacity of NAC supplementation (2% in drinking water for 6 weeks) to improve dystrophic muscle function and to explore broader systemic effects of NAC treatment. NAC treatment improved normalised measures of muscle function, and decreased inflammation and oxidative stress, but significantly reduced body weight gain, muscle weight and liver weight. Unexpected significant adverse effects of NAC on body and muscle weights indicate that interpretation of muscle function based on normalised force measures should be made with caution and careful consideration is needed when proposing the use of NAC as a therapeutic treatment for young DMD boys. Duchenne muscular dystrophy (DMD) is a fatal X-linked muscle wasting disease characterised by severe muscle weakness, necrosis, inflammation and oxidative stress. The antioxidant N-acetylcysteine (NAC) has been proposed as a potential therapeutic intervention for DMD boys. We investigated the capacity of NAC to improve dystrophic muscle function in the mdx mouse model of DMD. Young (6 weeks old) mdx and non-dystrophic C57 mice receiving 2% NAC in drinking water for 6 weeks were compared with untreated mice. Grip strength and body weight were measured weekly, before the 12 week old mice were anaesthetised and extensor digitorum longus (EDL) muscles were excised for functional analysis and tissues were sampled for biochemical analyses. Compared to untreated mice, the mean (SD) normalised grip strength was significantly greater in NAC-treated mdx [3.13 (0.58) vs 4.87 (0.78) g body weight (bw) -1 ; P < 0.001] and C57 mice [3.90 (0.32) vs 5.32 (0.60) g bw -1 ; P < 0.001]. Maximum specific force was significantly greater in NAC-treated mdx muscles [9.80 (2.27) vs 13.07 (3.37) N cm -2 ; P = 0.038]. Increased force in mdx mice was associated with reduced thiol oxidation and inflammation in fast muscles, and increased citrate synthase activity in slow muscle. Importantly, NAC significantly impaired body weight gain in both strains of young growing mice, and reduced liver weight in C57 mice and muscle weight in mdx mice. These potentially adverse effects of NAC emphasise the need for caution when interpreting improvements in muscle function based on normalised force measures, and that careful consideration be given to these effects when proposing NAC as a potential treatment for young DMD boys. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Chemotherapy-induced alopecia in mice. Induction by cyclophosphamide, inhibition by cyclosporine A, and modulation by dexamethasone.

PubMed Central

Paus, R.; Handjiski, B.; Eichmüller, S.; Czarnetzki, B. M.

1994-01-01

We introduce cyclophosphamide-induced alopecia (CYP-IA) in C57BL-6 mice as a clinically relevant model for studying the biology of chemotherapy-induced alopecia and for developing anti-alopecia drugs. One injection of CYP to mice with all back skin follicles in anagen VI induces severe alopecia that strikingly reproduces the follicle response, recovery, and histopathology seen in human CYP-IA. CYP dose-dependently induces abnormal follicular melanogenesis and dystrophic anagen or, in more severely damaged follicles, dystrophic catagen. Both dystrophy forms are followed by an extremely shortened telogen phase, but differ in the associated hair loss and in recovery patterns, which determines hair regrowth. This follicular response to CYP can be manipulated pharmacologically: systemic cyclosporine A shifts it toward a mild form of dystrophic anagen, thus retarding CYP-IA and prolonging "primary recovery". Topical dexamethasone, in contrast, forces follicles into dystrophic catagen, which augments CYP-IA, but accelerates the regrowth of normally pigmented hair ("secondary recovery"). Images Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 Figure 10 PMID:8160773

Efficacy and Safety of Human Retinal Progenitor Cells

PubMed Central

Semo, Ma'ayan; Haamedi, Nasrin; Stevanato, Lara; Carter, David; Brooke, Gary; Young, Michael; Coffey, Peter; Sinden, John; Patel, Sara; Vugler, Anthony

2016-01-01

Purpose We assessed the long-term efficacy and safety of human retinal progenitor cells (hRPC) using established rodent models. Methods Efficacy of hRPC was tested initially in Royal College of Surgeons (RCS) dystrophic rats immunosuppressed with cyclosporine/dexamethasone. Due to adverse effects of dexamethasone, this drug was omitted from a subsequent dose-ranging study, where different hRPC doses were tested for their ability to preserve visual function (measured by optokinetic head tracking) and retinal structure in RCS rats at 3 to 6 months after grafting. Safety of hRPC was assessed by subretinal transplantation into wild type (WT) rats and NIH-III nude mice, with analysis at 3 to 6 and 9 months after grafting, respectively. Results The optimal dose of hRPC for preserving visual function/retinal structure in dystrophic rats was 50,000 to 100,000 cells. Human retinal progenitor cells integrated/survived in dystrophic and WT rat retina up to 6 months after grafting and expressed nestin, vimentin, GFAP, and βIII tubulin. Vision and retinal structure remained normal in WT rats injected with hRPC and there was no evidence of tumors. A comparison between dexamethasone-treated and untreated dystrophic rats at 3 months after grafting revealed an unexpected reduction in the baseline visual acuity of dexamethasone-treated animals. Conclusions Human retinal progenitor cells appear safe and efficacious in the preclinical models used here. Translational Relevance Human retinal progenitor cells could be deployed during early stages of retinal degeneration or in regions of intact retina, without adverse effects on visual function. The ability of dexamethasone to reduce baseline visual acuity in RCS dystrophic rats has important implications for the interpretation of preclinical and clinical cell transplant studies. PMID:27486556

Cardiac Niche Influences the Direct Reprogramming of Canine Fibroblasts into Cardiomyocyte-Like Cells

PubMed Central

Palazzolo, Giacomo; Quattrocelli, Mattia; Toelen, Jaan; Dominici, Roberto; Tettamenti, Guido; Barthelemy, Inès; Blot, Stephane; Gijsbers, Rik; Cassano, Marco

2016-01-01

The Duchenne and Becker muscular dystrophies are caused by mutation of dystrophin gene and primarily affect skeletal and cardiac muscles. Cardiac involvement in dystrophic GRMD dogs has been demonstrated by electrocardiographic studies with the onset of a progressive cardiomyopathy similar to the cardiac disease in DMD patients. In this respect, GRMD is a useful model to explore cardiac and skeletal muscle pathogenesis and for developing new therapeutic protocols. Here we describe a protocol to convert GRMD canine fibroblasts isolated from heart and skin into induced cardiac-like myocytes (ciCLMs). We used a mix of transcription factors (GATA4, HAND2, TBX5, and MEF2C), known to be able to differentiate mouse and human somatic cells into ciCLMs. Exogenous gene expression was obtained using four lentiviral vectors carrying transcription factor genes and different resistance genes. Our data demonstrate a direct switch from fibroblast into ciCLMs with no activation of early cardiac genes. ciCLMs were unable to contract spontaneously, suggesting, differently from mouse and human cells, an incomplete differentiation process. However, when transplanted in neonatal hearts of SCID/Beige mice, ciCLMs participate in cardiac myogenesis. PMID:26681949

Cardiac Niche Influences the Direct Reprogramming of Canine Fibroblasts into Cardiomyocyte-Like Cells.

PubMed

Palazzolo, Giacomo; Quattrocelli, Mattia; Toelen, Jaan; Dominici, Roberto; Anastasia, Luigi; Tettamenti, Guido; Barthelemy, Inès; Blot, Stephane; Gijsbers, Rik; Cassano, Marco; Sampaolesi, Maurilio

2016-01-01

The Duchenne and Becker muscular dystrophies are caused by mutation of dystrophin gene and primarily affect skeletal and cardiac muscles. Cardiac involvement in dystrophic GRMD dogs has been demonstrated by electrocardiographic studies with the onset of a progressive cardiomyopathy similar to the cardiac disease in DMD patients. In this respect, GRMD is a useful model to explore cardiac and skeletal muscle pathogenesis and for developing new therapeutic protocols. Here we describe a protocol to convert GRMD canine fibroblasts isolated from heart and skin into induced cardiac-like myocytes (ciCLMs). We used a mix of transcription factors (GATA4, HAND2, TBX5, and MEF2C), known to be able to differentiate mouse and human somatic cells into ciCLMs. Exogenous gene expression was obtained using four lentiviral vectors carrying transcription factor genes and different resistance genes. Our data demonstrate a direct switch from fibroblast into ciCLMs with no activation of early cardiac genes. ciCLMs were unable to contract spontaneously, suggesting, differently from mouse and human cells, an incomplete differentiation process. However, when transplanted in neonatal hearts of SCID/Beige mice, ciCLMs participate in cardiac myogenesis.

Expression of heat shock protein in the atrophic corneal epithelium of the Royal College of Surgeons dystrophic rat.

PubMed

Yamaguchi, K; Yamaguchi, K; Sheedlo, H J; Turner, J E

1991-03-01

We report atrophic changes in the corneal epithelium of Royal College of Surgeons (RCS) dystrophic rats. The thickness of the corneal epithelium of 180-day-old RCS dystrophic rats was significantly decreased compared to that of 26-day-old RCS dystrophic and age-matched Sprague-Dawley (SD) rats. Immunostaining for (Na+ + K+) ATPase in the corneal epithelium of 180-day-old RCS dystrophic rats was dramatically reduced when compared to that of 26-day-old RCS dystrophic and age-matched SD rats. In contrast, heat shock protein immunostaining in the corneal epithelium was dense in all of the basal cells, wing cells, and superficial cells of 180-day-old RCS dystrophic rats but was minimally observed in some of the basal cells and in fewer wing and superficial cells of the corneal epithelium of 26-day-old RCS dystrophic and age-matched SD rats. We speculate that toxic products from the degenerating rod outer segments in the course of retinal dystrophy may affect the corneal epithelium, resulting in its atrophy. It is also possible that heat shock proteins appear in the atrophic corneal epithelium due to its degenerative condition.

Restoring Dystrophin Expression in Duchenne Muscular Dystrophy Muscle

PubMed Central

Hoffman, Eric P.; Bronson, Abby; Levin, Arthur A.; Takeda, Shin'ichi; Yokota, Toshifumi; Baudy, Andreas R.; Connor, Edward M.

2011-01-01

The identification of the Duchenne muscular dystrophy gene and protein in the late 1980s led to high hopes of rapid translation to molecular therapeutics. These hopes were fueled by early reports of delivering new functional genes to dystrophic muscle in mouse models using gene therapy and stem cell transplantation. However, significant barriers have thwarted translation of these approaches to true therapies, including insufficient therapeutic material (eg, cells and viral vectors), challenges in systemic delivery, and immunological hurdles. An alternative approach is to repair the patient's own gene. Two innovative small-molecule approaches have emerged as front-line molecular therapeutics: exon skipping and stop codon read through. Both approaches are in human clinical trials and aim to coax dystrophin protein production from otherwise inactive mutant genes. In the clinically severe dog model of Duchenne muscular dystrophy, the exon-skipping approach recently improved multiple functional outcomes. We discuss the status of these two methods aimed at inducing de novo dystrophin production from mutant genes and review implications for other disorders. PMID:21703390

Continued Expression of Neonatal Myosin Heavy Chain in Adult Dystrophic Skeletal Muscle

NASA Astrophysics Data System (ADS)

Bandman, Everett

1985-02-01

The expression of myosin heavy chain isoforms was examined in normal and dystrophic chicken muscle with a monoclonal antibody specific for neonatal myosin. Adult dystrophic muscle continued to contain neonatal myosin long after it disappeared from adult normal muscle. A new technique involving western blotting and peptide mapping demonstrated that the immunoreactive myosin in adult dystrophic muscle was identical to that found in neonatal normal muscle. Immunocytochemistry revealed that all fibers in the dystrophic muscle failed to repress neonatal myosin heavy chain. These studies suggest that muscular dystrophy inhibits the myosin gene switching that normally occurs during muscle maturation.

Chemical shift-based MRI to measure fat fractions in dystrophic skeletal muscle

PubMed Central

Triplett, William T.; Baligand, Celine; Forbes, Sean C.; Willcocks, Rebecca J.; Lott, Donovan J.; DeVos, Soren; Pollaro, Jim; Rooney, William D.; Sweeney, H. Lee; Bönnemann, Carsten; Wang, Dah-Jyuu; Vandenborne, Krista; Walter, Glenn A.

2014-01-01

Purpose The relationship between FF determined based on multiple TE, unipolar GE images and 1H-MRS was evaluated using different models for fat-water decomposition, signal-to-noise ratios (SNR), and excitation flip angles. Methods A combination of single voxel proton spectroscopy (1H-MRS) and gradient echo (GE) imaging was used to determine muscle fat fractions (FF) in both normal and dystrophic muscles. In order to cover a large range of FF, the soleus and vastus lateralis muscles of 22 unaffected control (CON), 16 subjects with Collagen VI (COL6), and 71 subjects with Duchenne muscular dystrophy (DMD) were studied. 1H-MRS based FF were corrected for the increased muscle 1H2O T1 and T2 values observed in dystrophic muscles. Results Excellent agreement was found between co-registered FF derived from GE images fit to a multipeak model with noise bias correction and the relaxation corrected 1H-MRS FF (y= 0.93×+0.003; R2=0.96) across the full range of FF. Relaxation corrected 1H-MRS FF and imaging based FF were significantly elevated (p<0.01) in both COL6 and DMD muscles. Conclusion FF, T2, and T1 were all sensitive to muscle involvement in dystrophic muscle. MRI offered an additional advantage over single voxel spectroscopy in that the tissue heterogeneity in FF could be readily determined. PMID:24006208

Nestin expression in the retina of rats with inherited retinal degeneration.

PubMed

Valamanesh, Fatemeh; Monnin, Julie; Morand-Villeneuve, Nadège; Michel, Germaine; Zaher, Murhaf; Miloudi, Sofiane; Chemouni, Deborah; Jeanny, Jean-Claude; Versaux-Botteri, Claudine

2013-05-01

Nestin is found in radial glia and neuronal/glial progenitor cells during retinal development, and is re-expressed after acute damage in the retina of adult mammals. We have investigated nestin expression in the retina of the Royal College of Surgeons (RCS) rat model of human inherited blindness, Retinitis pigmentosa (RP). During the first postnatal week, nestin immunoreactivity was located in elongated processes resembling radial glia in both control and dystrophic animals. During the second postnatal week, the density of nestin immunoreactive radial processes decreased progressively starting in the outer retina. At postnatal day 20 (PNd20), Nestin immunoreactive radial processes were no longer visible, with immunoreactivity restricted to structures resembling Müller end-feet and/or astrocytes located in the ganglion cell layer (GCL) in both control and dystrophic rats. These morphological results were confirmed by Western blotting and qPCR analysis. The level of nestin remained low in control animals at different time points up to 1 year, but we observed a re-expression of this protein from PNd30 in the dystrophic animals. The morphology of cells re-expressing nestin resembled that of radial glia and/or Muller cells, but co-localization of nestin and glutamine synthetase (GS: a marker of mature Müller cells) was only partial. Interestingly, whereas Western blot analysis confirmed the increase in protein levels from PNd30 onwards, mRNA levels remained low in dystrophic rats. Additional studies demonstrated that the discrepancy between protein and mRNA contents could be due to a dysfunction in proteasome activity as often observed in neurodegenerative pathologies. In conclusion, because of its localization in astrocytes and in radial processes resembling radial glia in the pathologic adult retina, nestin may be involved in mechanisms such as cell migration, generation of new neurons or glial cells and/or in retinal (re)modeling in dystrophic adult animals. The lack of concomitant up-regulation of mRNAs in adult dystrophic animals suggests that the pathology could lead to transcriptional and/or metabolic changes involving the stabilization of the half-life and/or dysregulation of degradation processes of nestin protein. Copyright © 2013 Elsevier Ltd. All rights reserved.

Satellite Cells in Muscular Dystrophy - Lost in Polarity

PubMed Central

Chang, Natasha C.; Chevalier, Fabien P.; Rudnicki, Michael A.

2016-01-01

Recent findings employing the mdx mouse model for Duchenne muscular dystrophy (DMD) have revealed that muscle satellite stem cells play a direct role in contributing to disease etiology and progression of DMD, the most common and severe form of muscular dystrophy. Lack of dystrophin expression in DMD has critical consequences in satellite cells including an inability to establish cell polarity, abrogation of asymmetric satellite stem cell divisions and failure to enter the myogenic program. Thus, muscle wasting in dystrophic mice is not only caused by myofiber fragility, but is exacerbated by intrinsic satellite cell dysfunction leading to impaired regeneration. Despite intense research and clinical efforts, there is still no effective cure for DMD. In this review, we highlight recent research advances in DMD and discuss the current state of treatment and importantly, how we can incorporate satellite cell-targeted therapeutic strategies to correct satellite cell dysfunction in DMD. PMID:27161598

High plasticity of axonal pathology in Alzheimer's disease mouse models.

PubMed

Blazquez-Llorca, Lidia; Valero-Freitag, Susana; Rodrigues, Eva Ferreira; Merchán-Pérez, Ángel; Rodríguez, J Rodrigo; Dorostkar, Mario M; DeFelipe, Javier; Herms, Jochen

2017-02-07

Axonal dystrophies (AxDs) are swollen and tortuous neuronal processes that are associated with extracellular depositions of amyloid β (Aβ) and have been observed to contribute to synaptic alterations occurring in Alzheimer's disease. Understanding the temporal course of this axonal pathology is of high relevance to comprehend the progression of the disease over time. We performed a long-term in vivo study (up to 210 days of two-photon imaging) with two transgenic mouse models (dE9xGFP-M and APP-PS1xGFP-M). Interestingly, AxDs were formed only in a quarter of GFP-expressing axons near Aβ-plaques, which indicates a selective vulnerability. AxDs, especially those reaching larger sizes, had long lifetimes and appeared as highly plastic structures with large variations in size and shape and axonal sprouting over time. In the case of the APP-PS1 mouse only, the formation of new long axonal segments in dystrophic axons (re-growth phenomenon) was observed. Moreover, new AxDs could appear at the same point of the axon where a previous AxD had been located before disappearance (re-formation phenomenon). In addition, we observed that most AxDs were formed and developed during the imaging period, and numerous AxDs had already disappeared by the end of this time. This work is the first in vivo study analyzing quantitatively the high plasticity of the axonal pathology around Aβ plaques. We hypothesized that a therapeutically early prevention of Aβ plaque formation or their growth might halt disease progression and promote functional axon regeneration and the recovery of neural circuits.

Multi-level omics analysis in a murine model of dystrophin loss and therapeutic restoration.

PubMed

Roberts, Thomas C; Johansson, Henrik J; McClorey, Graham; Godfrey, Caroline; Blomberg, K Emelie M; Coursindel, Thibault; Gait, Michael J; Smith, C I Edvard; Lehtiö, Janne; El Andaloussi, Samir; Wood, Matthew J A

2015-12-01

Duchenne muscular dystrophy (DMD) is a classical monogenic disorder, a model disease for genomic studies and a priority candidate for regenerative medicine and gene therapy. Although the genetic cause of DMD is well known, the molecular pathogenesis of disease and the response to therapy are incompletely understood. Here, we describe analyses of protein, mRNA and microRNA expression in the tibialis anterior of the mdx mouse model of DMD. Notably, 3272 proteins were quantifiable and 525 identified as differentially expressed in mdx muscle (P < 0.01). Therapeutic restoration of dystrophin by exon skipping induced widespread shifts in protein and mRNA expression towards wild-type expression levels, whereas the miRNome was largely unaffected. Comparison analyses between datasets showed that protein and mRNA ratios were only weakly correlated (r = 0.405), and identified a multitude of differentially affected cellular pathways, upstream regulators and predicted miRNA-target interactions. This study provides fundamental new insights into gene expression and regulation in dystrophic muscle. © The Author 2015. Published by Oxford University Press.

Dystrophin Is Required for the Normal Function of the Cardio-Protective KATP Channel in Cardiomyocytes

PubMed Central

Graciotti, Laura; Becker, Jodi; Granata, Anna Luisa; Procopio, Antonio Domenico; Tessarollo, Lino; Fulgenzi, Gianluca

2011-01-01

Duchenne and Becker muscular dystrophy patients often develop a cardiomyopathy for which the pathogenesis is still unknown. We have employed the murine animal model of Duchenne muscular dystrophy (mdx), which develops a cardiomyopathy that includes some characteristics of the human disease, to study the molecular basis of this pathology. Here we show that the mdx mouse heart has defects consistent with alteration in compounds that regulate energy homeostasis including a marked decrease in creatine-phosphate (PC). In addition, the mdx heart is more susceptible to anoxia than controls. Since the cardio-protective ATP sensitive potassium channel (KATP) complex and PC have been shown to interact we investigated whether deficits in PC levels correlate with other molecular events including KATP ion channel complex presence, its functionality and interaction with dystrophin. We found that this channel complex is present in the dystrophic cardiac cell membrane but its ability to sense a drop in the intracellular ATP concentration and consequently open is compromised by the absence of dystrophin. We further demonstrate that the creatine kinase muscle isoform (CKm) is displaced from the plasma membrane of the mdx cardiac cells. Considering that CKm is a determinant of KATP channel complex function we hypothesize that dystrophin acts as a scaffolding protein organizing the KATP channel complex and the enzymes necessary for its correct functioning. Therefore, the lack of proper functioning of the cardio-protective KATP system in the mdx cardiomyocytes may be part of the mechanism contributing to development of cardiac disease in dystrophic patients. PMID:22066028

Beneficial effects of high dose taurine treatment in juvenile dystrophic mdx mice are offset by growth restriction.

PubMed

Terrill, Jessica R; Pinniger, Gavin J; Nair, Keshav V; Grounds, Miranda D; Arthur, Peter G

2017-01-01

Duchenne Muscular Dystrophy (DMD) is a fatal muscle wasting disease manifested in young boys, for which there is no current cure. We have shown that the amino acid taurine is safe and effective at preventing dystropathology in the mdx mouse model for DMD. This study aimed to establish if treating growing mdx mice with a higher dose of taurine was more effective at improving strength and reducing inflammation and oxidative stress. Mice were treated with a dose of taurine estimated to be 16 g/kg/day, in drinking water from 1-6 weeks of age, after which in vivo and ex vivo muscle strength was assessed, as were measures of inflammation, oxidative stress and taurine metabolism. While the dose did decrease inflammation and protein oxidation in dystrophic muscles, there was no improvement in muscle strength (in contrast with benefits observed with the lower dose) and growth of the young mice was significantly restricted. We present novel data that a high taurine dose increases the cysteine content of both mdx liver and plasma, a possible result of down regulation of the taurine synthesis pathway in the liver (which functions to dispose of excess cysteine, which is toxic). These data caution that a high dose of taurine can have adverse effects and may be less efficacious than lower taurine doses. Therefore, monitoring of taurine dosage needs to be considered in future pre-clinical trials, in anticipation of using taurine as a clinical therapy for growing DMD boys (and other conditions).

Beneficial effects of high dose taurine treatment in juvenile dystrophic mdx mice are offset by growth restriction

PubMed Central

Pinniger, Gavin J.; Nair, Keshav V.; Grounds, Miranda D.; Arthur, Peter G.

2017-01-01

Duchenne Muscular Dystrophy (DMD) is a fatal muscle wasting disease manifested in young boys, for which there is no current cure. We have shown that the amino acid taurine is safe and effective at preventing dystropathology in the mdx mouse model for DMD. This study aimed to establish if treating growing mdx mice with a higher dose of taurine was more effective at improving strength and reducing inflammation and oxidative stress. Mice were treated with a dose of taurine estimated to be 16 g/kg/day, in drinking water from 1–6 weeks of age, after which in vivo and ex vivo muscle strength was assessed, as were measures of inflammation, oxidative stress and taurine metabolism. While the dose did decrease inflammation and protein oxidation in dystrophic muscles, there was no improvement in muscle strength (in contrast with benefits observed with the lower dose) and growth of the young mice was significantly restricted. We present novel data that a high taurine dose increases the cysteine content of both mdx liver and plasma, a possible result of down regulation of the taurine synthesis pathway in the liver (which functions to dispose of excess cysteine, which is toxic). These data caution that a high dose of taurine can have adverse effects and may be less efficacious than lower taurine doses. Therefore, monitoring of taurine dosage needs to be considered in future pre-clinical trials, in anticipation of using taurine as a clinical therapy for growing DMD boys (and other conditions). PMID:29095865

Long-term wheel running compromises diaphragm function but improves cardiac and plantarflexor function in the mdx mouse

PubMed Central

Acosta, Pedro; Sleeper, Meg M.; Barton, Elisabeth R.; Sweeney, H. Lee

2013-01-01

Dystrophin-deficient muscles suffer from free radical injury, mitochondrial dysfunction, apoptosis, and inflammation, among other pathologies that contribute to muscle fiber injury and loss, leading to wheelchair confinement and death in the patient. For some time, it has been appreciated that endurance training has the potential to counter many of these contributing factors. Correspondingly, numerous investigations have shown improvements in limb muscle function following endurance training in mdx mice. However, the effect of long-term volitional wheel running on diaphragm and cardiac function is largely unknown. Our purpose was to determine the extent to which long-term endurance exercise affected dystrophic limb, diaphragm, and cardiac function. Diaphragm specific tension was reduced by 60% (P < 0.05) in mice that performed 1 yr of volitional wheel running compared with sedentary mdx mice. Dorsiflexor mass (extensor digitorum longus and tibialis anterior) and function (extensor digitorum longus) were not altered by endurance training. In mice that performed 1 yr of volitional wheel running, plantarflexor mass (soleus and gastrocnemius) was increased and soleus tetanic force was increased 36%, while specific tension was similar in wheel-running and sedentary groups. Cardiac mass was increased 15%, left ventricle chamber size was increased 20% (diastole) and 18% (systole), and stroke volume was increased twofold in wheel-running compared with sedentary mdx mice. These data suggest that the dystrophic heart may undergo positive exercise-induced remodeling and that limb muscle function is largely unaffected. Most importantly, however, as the diaphragm most closely recapitulates the human disease, these data raise the possibility of exercise-mediated injury in dystrophic skeletal muscle. PMID:23823150

Transgenic mice expressing mutant Pinin exhibit muscular dystrophy, nebulin deficiency and elevated expression of slow-type muscle fiber genes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Hsu-Pin; Hsu, Shu-Yuan; Wu, Wen-Ai

Highlights: •Pnn CCD domain functions as a dominant negative mutant regulating Pnn expression and function. •Pnn CCD mutant Tg mice have a muscle wasting phenotype during development and show dystrophic histological features. •Pnn mutant muscles are susceptible to slow fiber type gene transition and NEB reduction. •The Tg mouse generated by overexpression of the Pnn CCD domain displays many characteristics resembling NEB{sup +/−} mice. -- Abstract: Pinin (Pnn) is a nuclear speckle-associated SR-like protein. The N-terminal region of the Pnn protein sequence is highly conserved from mammals to insects, but the C-terminal RS domain-containing region is absent in lower species.more » The N-terminal coiled-coil domain (CCD) is, therefore, of interest not only from a functional point of view, but also from an evolutionarily standpoint. To explore the biological role of the Pnn CCD in a physiological context, we generated transgenic mice overexpressing Pnn mutant in skeletal muscle. We found that overexpression of the CCD reduces endogenous Pnn expression in cultured cell lines as well as in transgenic skeletal muscle fibers. Pnn mutant mice exhibited reduced body mass and impaired muscle function during development. Mutant skeletal muscles show dystrophic histological features with muscle fibers heavily loaded with centrally located myonuclei. Expression profiling and pathway analysis identified over-representation of genes in gene categories associated with muscle contraction, specifically those related to slow type fiber. In addition nebulin (NEB) expression level is repressed in Pnn mutant skeletal muscle. We conclude that Pnn downregulation in skeletal muscle causes a muscular dystrophic phenotype associated with NEB deficiency and the CCD domain is incapable of replacing full length Pnn in terms of functional capacity.« less

Cannabinoid Receptor 2 Participates in Amyloid-β Processing in a Mouse Model of Alzheimer's Disease but Plays a Minor Role in the Therapeutic Properties of a Cannabis-Based Medicine.

PubMed

Aso, Ester; Andrés-Benito, Pol; Carmona, Margarita; Maldonado, Rafael; Ferrer, Isidre

2016-01-01

The endogenous cannabinoid system represents a promising therapeutic target to modify neurodegenerative pathways linked to Alzheimer's disease (AD). The aim of the present study was to evaluate the specific contribution of CB2 receptor to the progression of AD-like pathology and its role in the positive effect of a cannabis-based medicine (1:1 combination of Δ9-tetrahidrocannabinol and cannabidiol) previously demonstrated to be beneficial in the AβPP/PS1 transgenic model of the disease. A new mouse strain was generated by crossing AβPP/PS1 transgenic mice with CB2 knockout mice. Results show that lack of CB2 exacerbates cortical Aβ deposition and increases the levels of soluble Aβ40. However, CB2 receptor deficiency does not affect the viability of AβPP/PS1 mice, does not accelerate their memory impairment, does not modify tau hyperphosphorylation in dystrophic neurites associated to Aβ plaques, and does not attenuate the positive cognitive effect induced by the cannabis-based medicine in these animals. These findings suggest a minor role for the CB2 receptor in the therapeutic effect of the cannabis-based medicine in AβPP/PS1 mice, but also constitute evidence of a link between CB2 receptor and Aβ processing.

The anticancer drug tamoxifen counteracts the pathology in a mouse model of duchenne muscular dystrophy.

PubMed

Dorchies, Olivier M; Reutenauer-Patte, Julie; Dahmane, Elyes; Ismail, Heham M; Petermann, Olivier; Patthey- Vuadens, Ophélie; Comyn, Sophie A; Gayi, Elinam; Piacenza, Tony; Handa, Robert J; Décosterd, Laurent A; Ruegg, Urs T

2013-02-01

Duchenne muscular dystrophy (DMD) is a severe disorder characterized by progressive muscle wasting,respiratory and cardiac impairments, and premature death. No treatment exists so far, and the identification of active substances to fight DMD is urgently needed. We found that tamoxifen, a drug used to treat estrogen-dependent breast cancer, caused remarkable improvements of muscle force and of diaphragm and cardiac structure in the mdx(5Cv) mouse model of DMD. Oral tamoxifen treatment from 3 weeks of age for 15 months at a dose of 10 mg/kg/day stabilized myofiber membranes, normalized whole body force, and increased force production and resistance to repeated contractions of the triceps muscle above normal values. Tamoxifen improved the structure of leg muscles and diminished cardiac fibrosis by~ 50%. Tamoxifen also reduced fibrosis in the diaphragm, while increasing its thickness,myofiber count, and myofiber diameter, thereby augmenting by 72% the amount of contractile tissue available for respiratory function. Tamoxifen conferred a markedly slower phenotype to the muscles.Tamoxifen and its metabolites were present in nanomolar concentrations in plasma and muscles,suggesting signaling through high-affinity targets. Interestingly, the estrogen receptors ERa and ERb were several times more abundant in dystrophic than in normal muscles, and tamoxifen normalized the relative abundance of ERb isoforms. Our findings suggest that tamoxifen might be a useful therapy for DMD.

Identification of disease specific pathways using in vivo SILAC proteomics in dystrophin deficient mdx mouse.

PubMed

Rayavarapu, Sree; Coley, William; Cakir, Erdinc; Jahnke, Vanessa; Takeda, Shin'ichi; Aoki, Yoshitsugu; Grodish-Dressman, Heather; Jaiswal, Jyoti K; Hoffman, Eric P; Brown, Kristy J; Hathout, Yetrib; Nagaraju, Kanneboyina

2013-05-01

Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disorder caused by a mutation in the dystrophin gene. DMD is characterized by progressive weakness of skeletal, cardiac, and respiratory muscles. The molecular mechanisms underlying dystrophy-associated muscle weakness and damage are not well understood. Quantitative proteomics techniques could help to identify disease-specific pathways. Recent advances in the in vivo labeling strategies such as stable isotope labeling in mouse (SILAC mouse) with (13)C6-lysine or stable isotope labeling in mammals (SILAM) with (15)N have enabled accurate quantitative analysis of the proteomes of whole organs and tissues as a function of disease. Here we describe the use of the SILAC mouse strategy to define the underlying pathological mechanisms in dystrophin-deficient skeletal muscle. Differential SILAC proteome profiling was performed on the gastrocnemius muscles of 3-week-old (early stage) dystrophin-deficient mdx mice and wild-type (normal) mice. The generated data were further confirmed in an independent set of mdx and normal mice using a SILAC spike-in strategy. A total of 789 proteins were quantified; of these, 73 were found to be significantly altered between mdx and normal mice (p < 0.05). Bioinformatics analyses using Ingenuity Pathway software established that the integrin-linked kinase pathway, actin cytoskeleton signaling, mitochondrial energy metabolism, and calcium homeostasis are the pathways initially affected in dystrophin-deficient muscle at early stages of pathogenesis. The key proteins involved in these pathways were validated by means of immunoblotting and immunohistochemistry in independent sets of mdx mice and in human DMD muscle biopsies. The specific involvement of these molecular networks early in dystrophic pathology makes them potential therapeutic targets. In sum, our findings indicate that SILAC mouse strategy has uncovered previously unidentified pathological pathways in mouse models of human skeletal muscle disease.

Identification of Disease Specific Pathways Using in Vivo SILAC Proteomics in Dystrophin Deficient mdx Mouse*

PubMed Central

Rayavarapu, Sree; Coley, William; Cakir, Erdinc; Jahnke, Vanessa; Takeda, Shin'ichi; Aoki, Yoshitsugu; Grodish-Dressman, Heather; Jaiswal, Jyoti K.; Hoffman, Eric P.; Brown, Kristy J.; Hathout, Yetrib; Nagaraju, Kanneboyina

2013-01-01

Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disorder caused by a mutation in the dystrophin gene. DMD is characterized by progressive weakness of skeletal, cardiac, and respiratory muscles. The molecular mechanisms underlying dystrophy-associated muscle weakness and damage are not well understood. Quantitative proteomics techniques could help to identify disease-specific pathways. Recent advances in the in vivo labeling strategies such as stable isotope labeling in mouse (SILAC mouse) with 13C6-lysine or stable isotope labeling in mammals (SILAM) with 15N have enabled accurate quantitative analysis of the proteomes of whole organs and tissues as a function of disease. Here we describe the use of the SILAC mouse strategy to define the underlying pathological mechanisms in dystrophin-deficient skeletal muscle. Differential SILAC proteome profiling was performed on the gastrocnemius muscles of 3-week-old (early stage) dystrophin-deficient mdx mice and wild-type (normal) mice. The generated data were further confirmed in an independent set of mdx and normal mice using a SILAC spike-in strategy. A total of 789 proteins were quantified; of these, 73 were found to be significantly altered between mdx and normal mice (p < 0.05). Bioinformatics analyses using Ingenuity Pathway software established that the integrin-linked kinase pathway, actin cytoskeleton signaling, mitochondrial energy metabolism, and calcium homeostasis are the pathways initially affected in dystrophin-deficient muscle at early stages of pathogenesis. The key proteins involved in these pathways were validated by means of immunoblotting and immunohistochemistry in independent sets of mdx mice and in human DMD muscle biopsies. The specific involvement of these molecular networks early in dystrophic pathology makes them potential therapeutic targets. In sum, our findings indicate that SILAC mouse strategy has uncovered previously unidentified pathological pathways in mouse models of human skeletal muscle disease. PMID:23297347

Loss of calretinin immunoreactive fibers in subcortical visual recipient structures of the RCS dystrophic rat.

PubMed

Vugler, Anthony A; Coffey, Peter J

2003-11-01

The retinae of dystrophic Royal College of Surgeons (RCS) rats exhibit progressive photoreceptor degeneration accompanied by pathology of ganglion cells. To date, little work has examined the consequences of retinal degeneration for central visual structures in dystrophic rats. Here, we use immunohistochemistry for calretinin (CR) to label retinal afferents in the superior colliculus (SC), lateral geniculate nucleus, and olivary pretectal nucleus of RCS rats aged between 2 and 26 months of age. Early indications of fiber loss in the medial dystrophic SC were apparent between 9 and 13 months. Quantitative methods reveal a significant reduction in the level of CR immunoreactivity in visual layers of the medial dystrophic SC at 13 months (P < 0.02). In dystrophic animals aged 19-26 months the loss of CR fibers in SC was dramatic, with well-defined patches of fiber degeneration predominating in medial aspects of the structure. This fiber degeneration in SC was accompanied by increased detection of cells immunoreactive for CR. In several animals, regions of fiber loss were also found to contain strongly parvalbumin-immunoreactive cells. Loss of CR fibers was also observed in the lateral geniculate nucleus and olivary pretectal nucleus. Patterns of fiber loss in the dystrophic SC compliment reports of ganglion cell degeneration in these animals and the response of collicular neurons to degeneration is discussed in terms of plasticity of the dystrophic visual system and properties of calcium binding proteins.

Effects of Passive Physical Exercise on Peripheral Vision in Muscular Dystrophic Children.

ERIC Educational Resources Information Center

Eickelberg, Warren; And Others

1983-01-01

The effects of passive exercise of the extremities on peripheral vision of muscular dystrophic children aged 9 to 13 years was investigated. Compared to control subjects, those who experienced six minutes of passive exercise evidenced increased peripheral vision. Curriculum revisions for muscular dystrophic children indicate the importance of…

A protein anomaly in erythrocyte membranes of patients with Duchenne muscular dystrophy

PubMed Central

1983-01-01

Raman spectroscopic comparisons of erythrocyte membranes from 20 patients with Duchenne muscular dystrophy and 8 age-matched controls indicate a prominent and consistent protein anomaly in the patient samples. This was apparent in the following: (a) CH-stretching signals from control membranes reveal a thermotropic transition at 15.6 degrees C, attributable to a protein/lipid phase that is lacking in dystrophic membranes. (b) CH-stretching signals from control membranes also show a protein transition at 39 degrees C [pH 7.4] that is shifted to 45 degrees in dystrophic membranes. (c) A reduction in pH to 5.7 shifts this transition from 39 degrees C to 7 degrees C in normal membranes and from 45 degrees C to 24 degrees C in dystrophic membranes. (d) The Amide I/Amide III regions indicate a significant proportion of beta- structured peptide in dystrophic but not normal membranes. (e) Analysis of tyrosine signals indicates greater polar exposure of tyrosine hydroxyl groups in dystrophic vs normal membranes. All of the differences between dystrophic and normal membranes are highly significant (P less than 0.001). PMID:6854213

Innate sensing of microbial products promotes wound-induced skin cancer.

PubMed

Hoste, Esther; Arwert, Esther N; Lal, Rohit; South, Andrew P; Salas-Alanis, Julio C; Murrell, Dedee F; Donati, Giacomo; Watt, Fiona M

2015-01-09

The association between tissue damage, chronic inflammation and cancer is well known. However, the underlying mechanisms are unclear. Here we characterize a mouse model in which constitutive epidermal extracellular-signal-regulated kinase-MAP-kinase signalling results in epidermal inflammation, and skin wounding induces tumours. We show that tumour incidence correlates with wound size and inflammatory infiltrate. Ablation of tumour necrosis factor receptor (TNFR)-1/-2, Myeloid Differentiation primary response gene 88 or Toll-like receptor (TLR)-5, the bacterial flagellin receptor, but not other innate immune sensors, in radiosensitive leukocytes protects against tumour formation. Antibiotic treatment inhibits, whereas injection of flagellin induces, tumours in a TLR-5-dependent manner. TLR-5 is also involved in chemical-induced skin carcinogenesis in wild-type mice. Leukocytic TLR-5 signalling mediates upregulation of the alarmin HMGB1 (High Mobility Group Box 1) in wound-induced papillomas. HMGB1 is elevated in tumours of patients with Recessive Dystrophic Epidermolysis Bullosa, a disease characterized by chronic skin damage. We conclude that in our experimental model the combination of bacteria, chronic inflammation and wounding cooperate to trigger skin cancer.

Innate sensing of microbial products promotes wound-induced skin cancer

PubMed Central

Hoste, Esther; Arwert, Esther N.; Lal, Rohit; South, Andrew P.; Salas-Alanis, Julio C.; Murrell, Dedee F.; Donati, Giacomo; Watt, Fiona M.

2015-01-01

The association between tissue damage, chronic inflammation and cancer is well known. However, the underlying mechanisms are unclear. Here we characterize a mouse model in which constitutive epidermal extracellular-signal-regulated kinase-MAP-kinase signalling results in epidermal inflammation, and skin wounding induces tumours. We show that tumour incidence correlates with wound size and inflammatory infiltrate. Ablation of tumour necrosis factor receptor (TNFR)-1/-2, Myeloid Differentiation primary response gene 88 or Toll-like receptor (TLR)-5, the bacterial flagellin receptor, but not other innate immune sensors, in radiosensitive leukocytes protects against tumour formation. Antibiotic treatment inhibits, whereas injection of flagellin induces, tumours in a TLR-5-dependent manner. TLR-5 is also involved in chemical-induced skin carcinogenesis in wild-type mice. Leukocytic TLR-5 signalling mediates upregulation of the alarmin HMGB1 (High Mobility Group Box 1) in wound-induced papillomas. HMGB1 is elevated in tumours of patients with Recessive Dystrophic Epidermolysis Bullosa, a disease characterized by chronic skin damage. We conclude that in our experimental model the combination of bacteria, chronic inflammation and wounding cooperate to trigger skin cancer. PMID:25575023

Mineralization/Anti-Mineralization Networks in the Skin and Vascular Connective Tissues

PubMed Central

Li, Qiaoli; Uitto, Jouni

2014-01-01

Ectopic mineralization has been linked to several common clinical conditions with considerable morbidity and mortality. The mineralization processes, both metastatic and dystrophic, affect the skin and vascular connective tissues. There are several contributing metabolic and environmental factors that make uncovering of the precise pathomechanisms of these acquired disorders exceedingly difficult. Several relatively rare heritable disorders share phenotypic manifestations similar to those in common conditions, and, consequently, they serve as genetically controlled model systems to study the details of the mineralization process in peripheral tissues. This overview will highlight diseases with mineral deposition in the skin and vascular connective tissues, as exemplified by familial tumoral calcinosis, pseudoxanthoma elasticum, generalized arterial calcification of infancy, and arterial calcification due to CD73 deficiency. These diseases, and their corresponding mouse models, provide insight into the pathomechanisms of soft tissue mineralization and point to the existence of intricate mineralization/anti-mineralization networks in these tissues. This information is critical for understanding the pathomechanistic details of different mineralization disorders, and it has provided the perspective to develop pharmacological approaches to counteract the consequences of ectopic mineralization. PMID:23665350

IGF-I treatment improves the functional properties of fast- and slow-twitch skeletal muscles from dystrophic mice.

PubMed

Lynch, G S; Cuffe, S A; Plant, D R; Gregorevic, P

2001-04-01

Although insulin-like growth factor-I (IGF-I) has been proposed for use by patients suffering from muscle wasting conditions, few studies have investigated the functional properties of dystrophic skeletal muscle following IGF-I treatment. 129P1 ReJ-Lama2(dy) (129 ReJ dy/dy) dystrophic mice suffer from a deficiency in the structural protein, laminin, and exhibit severe muscle wasting and weakness. We tested the hypothesis that 4 weeks of IGF-I treatment ( approximately 2 mg/kg body mass, 50 g/h via mini-osmotic pump, subcutaneously) would increase the mass and force producing capacity of skeletal muscles from dystrophic mice. IGF-I treatment increased the mass of the extensor digitorum longus (EDL) and soleus muscles of dystrophic mice by 20 and 29%, respectively, compared with untreated dystrophic mice (administered saline-vehicle only). Absolute maximum force (P(o)) of the EDL and soleus muscle was increased by 40 and 32%, respectively, following IGF-I treatment. Specific P(o) (sP(o)) was increased by 23% in the EDL muscles of treated compared with untreated mice, but in the soleus muscle sP(o) was unchanged. IGF-I treatment increased the proportion of type IIB and type IIA fibres and decreased the proportion of type I fibres in the EDL muscles of dystrophic mice. In the soleus muscles of dystrophic mice, IGF-I treatment increased the proportion of type IIA fibres and decreased the proportion of type I fibres. Average fibre cross-sectional area was increased in the EDL and soleus muscles of treated compared with untreated mice. We conclude that IGF-I treatment ameliorates muscle wasting and improves the functional properties of skeletal muscles of dystrophic mice. The findings have important implications for the role of IGF-I in ameliorating muscle wasting associated with the muscular dystrophies.

Evolving therapeutic strategies for Duchenne muscular dystrophy: targeting downstream events.

PubMed

Tidball, James G; Wehling-Henricks, Michelle

2004-12-01

Duchenne muscular dystrophy (DMD) is a progressive, lethal, muscle wasting disease that affects 1 of 3500 boys born worldwide. The disease results from mutation of the dystrophin gene that encodes a cytoskeletal protein associated with the muscle cell membrane. Although gene therapy will likely provide the cure for DMD, it remains on the distant horizon, emphasizing the need for more rapid development of palliative treatments that build on improved understanding of the complex pathology of dystrophin deficiency. In this review, we have focused on therapeutic strategies that target downstream events in the pathologic progression of DMD. Much of this work has been developed initially using the dystrophin-deficient mdx mouse to explore basic features of the pathophysiology of dystrophin deficiency and to test potential therapeutic interventions to slow, reverse, or compensate for functional losses that occur in muscular dystrophy. In some cases, the initial findings in the mdx model have led to clinical treatments for DMD boys that have produced improvements in muscle function and quality of life. Many of these investigations have concerned interventions that can affect protein balance in muscle, by inhibiting specific proteases implicated in the DMD pathology, or by providing anabolic factors or depleting catabolic factors that can contribute to muscle wasting. Other investigations have exploited the use of anti-inflammatory agents that can reduce the contribution of leukocytes to promoting secondary damage to dystrophic muscle. A third general strategy is designed to increase the regenerative capacity of dystrophic muscle and thereby help retain functional muscle mass. Each of these general approaches to slowing the pathology of dystrophin deficiency has yielded encouragement and suggests that targeting downstream events in dystrophinopathy can yield worthwhile, functional improvements in DMD.

Evidence of Tau Hyperphosphorylation and Dystrophic Microglia in the Common Marmoset.

PubMed

Rodriguez-Callejas, Juan D; Fuchs, Eberhard; Perez-Cruz, Claudia

2016-01-01

Common marmosets ( Callithrix jacchus ) have recently gained popularity in biomedical research as models of aging research. Basically, they confer advantages from other non-human primates due to their shorter lifespan with onset of appearance of aging at 8 years. Old marmosets present some markers linked to neurodegeneration in the brain such as amyloid beta (Aβ) 1-42 and Aβ 1-40 . However, there are no studies exploring other cellular markers associated with neurodegenerative diseases in this non-human primate. Using immunohistochemistry, we analyzed brains of male adolescent, adult, old, and aged marmosets. We observed accumulation of Aβ 1-40 and Aβ 1-42 in the cortex of aged subjects. Tau hyperphosphorylation was already detected in the brain of adolescent animals and increased with aging in a more fibrillary form. Microglia activation was also observed in the aging process, while a dystrophic phenotype accumulates in aged subjects. Interestingly, dystrophic microglia contained hyperphosphorylated tau, but active microglia did not. These results support previous findings regarding microglia dysfunctionality in aging and neurodegenerative diseases as Alzheimer's disease. Further studies should explore the functional consequences of these findings to position this non-human primate as animal model of aging and neurodegeneration.

Evidence of Tau Hyperphosphorylation and Dystrophic Microglia in the Common Marmoset

PubMed Central

Rodriguez-Callejas, Juan D.; Fuchs, Eberhard; Perez-Cruz, Claudia

2016-01-01

Common marmosets (Callithrix jacchus) have recently gained popularity in biomedical research as models of aging research. Basically, they confer advantages from other non-human primates due to their shorter lifespan with onset of appearance of aging at 8 years. Old marmosets present some markers linked to neurodegeneration in the brain such as amyloid beta (Aβ)1-42 and Aβ1-40. However, there are no studies exploring other cellular markers associated with neurodegenerative diseases in this non-human primate. Using immunohistochemistry, we analyzed brains of male adolescent, adult, old, and aged marmosets. We observed accumulation of Aβ1-40 and Aβ1-42 in the cortex of aged subjects. Tau hyperphosphorylation was already detected in the brain of adolescent animals and increased with aging in a more fibrillary form. Microglia activation was also observed in the aging process, while a dystrophic phenotype accumulates in aged subjects. Interestingly, dystrophic microglia contained hyperphosphorylated tau, but active microglia did not. These results support previous findings regarding microglia dysfunctionality in aging and neurodegenerative diseases as Alzheimer’s disease. Further studies should explore the functional consequences of these findings to position this non-human primate as animal model of aging and neurodegeneration. PMID:28066237

Humoral immunity to AAV-6, 8, and 9 in normal and dystrophic dogs.

PubMed

Shin, Jin-Hong; Yue, Yongping; Smith, Bruce; Duan, Dongsheng

2012-03-01

Adeno-associated virus (AAV)-6, 8, and 9 are promising gene-delivery vectors for testing novel Duchenne muscular dystrophy gene therapy in the canine model. Humoral immunity greatly influences in vivo AAV transduction. However, neutralizing antibodies to AAV-6, 8, and 9 have not been systemically examined in normal and dystrophic dogs. To gain information on the seroprevalence of antibodies to AAV-6, 8, and 9, we measured neutralizing antibody titers using an in vitro transduction inhibition assay. We examined 72 naive serum samples and 26 serum samples obtained from dogs that had received AAV gene transfer. Our data demonstrated that AAV-6 neutralizing antibody was the most prevalent antibody in dogs irrespective of age, gender, disease status (dystrophic or not), and prior parvovirus vaccination history. Surprisingly, high-level anti-AAV-6 antibody was detected at birth in newborn puppies. Further, a robust antibody response was induced in affected, but not normal newborn dogs following systemic AAV gene transfer. Taken together, our data have provided an important baseline on the seroprevalence of AAV-6, 8, and 9 neutralizing antibodies in normal and Duchenne muscular dystrophy dogs. These results will help guide translational AAV gene-therapy studies in dog models of muscular dystrophy.

Alzheimer's disease pathological lesions activate the spleen tyrosine kinase.

PubMed

Schweig, Jonas Elias; Yao, Hailan; Beaulieu-Abdelahad, David; Ait-Ghezala, Ghania; Mouzon, Benoit; Crawford, Fiona; Mullan, Michael; Paris, Daniel

2017-09-06

The pathology of Alzheimer's disease (AD) is characterized by dystrophic neurites (DNs) surrounding extracellular Aβ-plaques, microgliosis, astrogliosis, intraneuronal tau hyperphosphorylation and aggregation. We have previously shown that inhibition of the spleen tyrosine kinase (Syk) lowers Aβ production and tau hyperphosphorylation in vitro and in vivo. Here, we demonstrate that Aβ-overexpressing Tg PS1/APPsw, Tg APPsw mice, and tau overexpressing Tg Tau P301S mice exhibit a pathological activation of Syk compared to wild-type littermates. Syk activation is occurring in a subset of microglia and is age-dependently increased in Aβ-plaque-associated dystrophic neurites of Tg PS1/APPsw and Tg APPsw mice. In Tg Tau P301S mice, a pure model of tauopathy, activated Syk occurs in neurons that show an accumulation of misfolded and hyperphosphorylated tau in the cortex and hippocampus. Interestingly, the tau pathology is exacerbated in neurons that display high levels of Syk activation supporting a role of Syk in the formation of tau pathological species in vivo. Importantly, human AD brain sections show both pathological Syk activation in DNs around Aβ deposits and in neurons immunopositive for pathological tau species recapitulating the data obtained in transgenic mouse models of AD. Additionally, we show that Syk overexpression leads to increased tau accumulation and promotes tau hyperphosphorylation at multiple epitopes in human neuron-like SH-SY5Y cells, further supporting a role of Syk in the formation of tau pathogenic species. Collectively, our data show that Syk activation occurs following Aβ deposition and the formation of tau pathological species. Given that we have previously shown that Syk activation also promotes Aβ formation and tau hyperphosphorylation, our data suggest that AD pathological lesions may be self-propagating via a Syk dependent mechanism highlighting Syk as an attractive therapeutic target for the treatment of AD.

Study of axonal dystrophy. II Dystrophy and atrophy of the presynaptic boutons: a dual pathology.

PubMed

Fujisawa, K; Shiraki, H

1980-01-01

In succession to the previous quantitative work, a qualitative study has been carried out on the nature of a dual pathology affecting presynaptic boutons in the posterior tract nuclei of ageing rats. Based on the morphology of dystrophic boutons in early stage, it is concluded that the initial and therefore essential characteristic of dystrophic process is an abnormal increase of normal axonal components within the presynaptic boutons, and that various abnormal substructures of spheroids hitherto reported in the literature are probably the results of their secondary metamorphosis. The dystrophic process within the posterior tract nuclei is a selective one, involving presynaptic boutons and preterminal axons only of the posterior tract fibres. Comparison of the frequency of early dystrophic boutons and of fully grown-up spheroids indicates that a small percentage of boutons deriving from posterior tract fibres become dystrophic and of these dystrophic boutons only a small percentage again continue to develop unto large spheroids, throughout lifespan of the animals. On the other hand, in search of a morphological counterpart for the age-related decrease of volume ratio of presynaptic boutons to the neuropil, some dubious atrophic changes were also found in presynaptic boutons, which could have been easily missed from observation if studied qualitatively alone. Accordingly, no less numerous boutons other than dystrophic ones are supposed to atrophy 'independently' and to disappear 'silently' during the same period. The dystrophic and the atrophic changes involve different boutons (of different or the same terminal axons) within the same gray matter. This dual pathology of boutons needs further elucidation of its neurocytopathological as well as neurobiological background in the future.

Recessive Dystrophic Epidermolysis Bullosa and Pregnancy.

PubMed

Boria, F; Maseda, R; Martín-Cameán, M; De la Calle, M; de Lucas, R

2017-12-01

Dystrophic epidermolysis bullosa is a rare inherited disease caused by mutations in the COL7A1 gene. Its recessive variant (recessive dystrophic epidermolysis bullosa) is characterized by the absence or considerably reduced expression of type VII collagen, which leads to marked fragility of the skin and mucous membranes and subsequent blister formation, whether spontaneously or following minimal injury. There have been very few reports of this disease in pregnant women. We present 2 cases of pregnant women with recessive dystrophic epidermolysis bullosa managed in our High-Risk Pregnancy Unit at Hospital Universitario La Paz, Madrid, Spain. Both patients underwent full-term cesarean delivery, with no further complications for mother or child. Although recessive dystrophic epidermolysis bullosa increases the risk of maternal complications, a patient is not advised against pregnancy. With adequate monitoring, these patients can fulfil their desire to become mothers. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Muscle-specific CRISPR/Cas9 dystrophin gene editing ameliorates pathophysiology in a mouse model for Duchenne muscular dystrophy

PubMed Central

Bengtsson, Niclas E.; Hall, John K.; Odom, Guy L.; Phelps, Michael P.; Andrus, Colin R.; Hawkins, R. David; Hauschka, Stephen D.; Chamberlain, Joel R.; Chamberlain, Jeffrey S.

2017-01-01

Gene replacement therapies utilizing adeno-associated viral (AAV) vectors hold great promise for treating Duchenne muscular dystrophy (DMD). A related approach uses AAV vectors to edit specific regions of the DMD gene using CRISPR/Cas9. Here we develop multiple approaches for editing the mutation in dystrophic mdx4cv mice using single and dual AAV vector delivery of a muscle-specific Cas9 cassette together with single-guide RNA cassettes and, in one approach, a dystrophin homology region to fully correct the mutation. Muscle-restricted Cas9 expression enables direct editing of the mutation, multi-exon deletion or complete gene correction via homologous recombination in myogenic cells. Treated muscles express dystrophin in up to 70% of the myogenic area and increased force generation following intramuscular delivery. Furthermore, systemic administration of the vectors results in widespread expression of dystrophin in both skeletal and cardiac muscles. Our results demonstrate that AAV-mediated muscle-specific gene editing has significant potential for therapy of neuromuscular disorders. PMID:28195574

microRNA-206 promotes skeletal muscle regeneration and delays progression of Duchenne muscular dystrophy in mice

PubMed Central

Liu, Ning; Williams, Andrew H.; Maxeiner, Johanna M.; Bezprozvannaya, Svetlana; Shelton, John M.; Richardson, James A.; Bassel-Duby, Rhonda; Olson, Eric N.

2012-01-01

Skeletal muscle injury activates adult myogenic stem cells, known as satellite cells, to initiate proliferation and differentiation to regenerate new muscle fibers. The skeletal muscle–specific microRNA miR-206 is upregulated in satellite cells following muscle injury, but its role in muscle regeneration has not been defined. Here, we show that miR-206 promotes skeletal muscle regeneration in response to injury. Genetic deletion of miR-206 in mice substantially delayed regeneration induced by cardiotoxin injury. Furthermore, loss of miR-206 accelerated and exacerbated the dystrophic phenotype in a mouse model of Duchenne muscular dystrophy. We found that miR-206 acts to promote satellite cell differentiation and fusion into muscle fibers through suppressing a collection of negative regulators of myogenesis. Our findings reveal an essential role for miR-206 in satellite cell differentiation during skeletal muscle regeneration and indicate that miR-206 slows progression of Duchenne muscular dystrophy. PMID:22546853

Evidence for ACTN3 as a genetic modifier of Duchenne muscular dystrophy

PubMed Central

Hogarth, Marshall W.; Houweling, Peter J.; Thomas, Kristen C.; Gordish-Dressman, Heather; Bello, Luca; Vishwanathan, V.; Chidambaranathan, S.; Douglas Biggar, W.; McAdam, Laura C.; Mah, Jean K.; Tulinius, Mar; Cnaan, Avital; Morgenroth, Lauren P.; Leshner, Robert; Tesi-Rocha, Carolina; Thangarajh, Mathula; Duong, Tina; Kornberg, Andrew; Ryan, Monique; Nevo, Yoram; Dubrovsky, Alberto; Clemens, Paula R.; Abdel-Hamid, Hoda; Connolly, Anne M.; Pestronk, Alan; Teasley, Jean; Bertorini, Tulio E.; Webster, Richard; Kolski, Hanna; Kuntz, Nancy; Driscoll, Sherilyn; Bodensteiner, John B.; Carlo, Jose; Gorni, Ksenija; Lotze, Timothy; Day, John W.; Karachunski, Peter; Henricson, Erik K.; Abresch, Richard T.; McDonald, Craig M.; Pegoraro, Elena; Hoffman, Eric P.; Head, Stewart I.; North, Kathryn N.

2017-01-01

Duchenne muscular dystrophy (DMD) is characterized by muscle degeneration and progressive weakness. There is considerable inter-patient variability in disease onset and progression, which can confound the results of clinical trials. Here we show that a common null polymorphism (R577X) in ACTN3 results in significantly reduced muscle strength and a longer 10 m walk test time in young, ambulant patients with DMD; both of which are primary outcome measures in clinical trials. We have developed a double knockout mouse model, which also shows reduced muscle strength, but is protected from stretch-induced eccentric damage with age. This suggests that α-actinin-3 deficiency reduces muscle performance at baseline, but ameliorates the progression of dystrophic pathology. Mechanistically, we show that α-actinin-3 deficiency triggers an increase in oxidative muscle metabolism through activation of calcineurin, which likely confers the protective effect. Our studies suggest that ACTN3 R577X genotype is a modifier of clinical phenotype in DMD patients. PMID:28139640

Skeletal muscle repair in a mouse model of nemaline myopathy

PubMed Central

Sanoudou, Despina; Corbett, Mark A.; Han, Mei; Ghoddusi, Majid; Nguyen, Mai-Anh T.; Vlahovich, Nicole; Hardeman, Edna C.; Beggs, Alan H.

2012-01-01

Nemaline myopathy (NM), the most common non-dystrophic congenital myopathy, is a variably severe neuromuscular disorder for which no effective treatment is available. Although a number of genes have been identified in which mutations can cause NM, the pathogenetic mechanisms leading to the phenotypes are poorly understood. To address this question, we examined gene expression patterns in an NM mouse model carrying the human Met9Arg mutation of alpha-tropomyosin slow (Tpm3). We assessed five different skeletal muscles from affected mice, which are representative of muscles with differing fiber-type compositions, different physiological specializations and variable degrees of pathology. Although these same muscles in non-affected mice showed marked variation in patterns of gene expression, with diaphragm being the most dissimilar, the presence of the mutant protein in nemaline muscles resulted in a more similar pattern of gene expression among the muscles. This result suggests a common process or mechanism operating in nemaline muscles independent of the variable degrees of pathology. Transcriptional and protein expression data indicate the presence of a repair process and possibly delayed maturation in nemaline muscles. Markers indicative of satellite cell number, activated satellite cells and immature fibers including M-Cadherin, MyoD, desmin, Pax7 and Myf6 were elevated by western-blot analysis or immunohistochemistry. Evidence suggesting elevated focal repair was observed in nemaline muscle in electron micrographs. This analysis reveals that NM is characterized by a novel repair feature operating in multiple different muscles. PMID:16877500

Skeletal muscle repair in a mouse model of nemaline myopathy.

PubMed

Sanoudou, Despina; Corbett, Mark A; Han, Mei; Ghoddusi, Majid; Nguyen, Mai-Anh T; Vlahovich, Nicole; Hardeman, Edna C; Beggs, Alan H

2006-09-01

Nemaline myopathy (NM), the most common non-dystrophic congenital myopathy, is a variably severe neuromuscular disorder for which no effective treatment is available. Although a number of genes have been identified in which mutations can cause NM, the pathogenetic mechanisms leading to the phenotypes are poorly understood. To address this question, we examined gene expression patterns in an NM mouse model carrying the human Met9Arg mutation of alpha-tropomyosin slow (Tpm3). We assessed five different skeletal muscles from affected mice, which are representative of muscles with differing fiber-type compositions, different physiological specializations and variable degrees of pathology. Although these same muscles in non-affected mice showed marked variation in patterns of gene expression, with diaphragm being the most dissimilar, the presence of the mutant protein in nemaline muscles resulted in a more similar pattern of gene expression among the muscles. This result suggests a common process or mechanism operating in nemaline muscles independent of the variable degrees of pathology. Transcriptional and protein expression data indicate the presence of a repair process and possibly delayed maturation in nemaline muscles. Markers indicative of satellite cell number, activated satellite cells and immature fibers including M-Cadherin, MyoD, desmin, Pax7 and Myf6 were elevated by western-blot analysis or immunohistochemistry. Evidence suggesting elevated focal repair was observed in nemaline muscle in electron micrographs. This analysis reveals that NM is characterized by a novel repair feature operating in multiple different muscles.

Prevention of pathology in mdx mice by expression of utrophin: analysis using an inducible transgenic expression system.

PubMed

Squire, S; Raymackers, J M; Vandebrouck, C; Potter, A; Tinsley, J; Fisher, R; Gillis, J M; Davies, K E

2002-12-15

Duchenne muscular dystrophy results from the absence of dystrophin, a cytoskeletal protein. Previously, we have shown in a transgenic mouse model of the disease (mdx) that high levels of expression of the dystrophin-related protein, utrophin can prevent pathology. We developed a new transgenic mouse model where muscle specific utrophin expression was conditioned by addition of tetracycline in water. Transgene expression was turned on at different time points: in utero, at birth, 10 and 30 days after birth. We obtained moderate levels of expression, variable from fibre to fibre (mosaicism) but sufficient to induce a correct localization of the dystro-sarcoglycan complex. Histology revealed a reduction of necrotic foci and of the percentage of centronucleated fibres, which remained still largely above the normal level. Isometric force was not improved but the resistance to eccentric contractions was significantly stronger. When utrophin expression was activated 30 days after birth, improvements were marginal, suggesting that the age at which utrophin therapy is initiated could be an important factor. Our results also provide an unexpected insight into the pathogenesis of the dystrophinopathies. We observed a complete normalization of the characteristics of the mechano-sensitive/voltage-independent Ca(2+) channels (occurrence, open probabilities and Ca(2+) currents), while the classical markers of dystrophy were still abnormal. These observations question the role of increased Ca(2+) channel activity in initiating the dystrophic process. The new model shows that utrophin therapy, initiated after birth, can be effective, but the extent of correction of the various symptoms of dystrophinopathy critically depends on the amount of utrophin expressed.

TGF-β1 activates the canonical NF-κB signaling to promote cell survival and proliferation in dystrophic muscle fibroblasts in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Zhen-Yu; Department of Neurology, The Second Affiliated Hospital, Guangzhou Medical University, No.250 Changgang East Road, Guangzhou 510260, Guangdong Province; Zhong, Zhi-Gang

Activated fibroblasts continue to proliferate at injury sites, leading to progressive muscular fibrosis in Duchenne muscular dystrophy (DMD). TGF-β1 is a dominant profibrotic mediator thought to play a critical role in muscle fibrosis; however, the implicated mechanisms are not fully understood. Here we showed that TGF-β1 increased the resistance to apoptosis and stimulated cell cycle progression in dystrophic muscle fibroblasts under serum deprivation conditions in vitro. TGF-β1 treatment activated the canonical NF-κB pathway; and we found that pharmacological inhibition of IKKβ with IMD-0354 and RelA gene knockdown with siRNA attenuated these effects of TGF-β1 on dystrophic muscle fibroblasts. Collectively, our datamore » suggest that TGF-β1 prevents apoptosis and cell cycle arrest in dystrophic muscle fibroblasts through the canonical NF-κB signaling pathway. - Highlights: • TGF-β1 promotes survival and proliferation in dystrophic muscle fibroblasts. • TGF-β1 activated the canonical NF-κB pathway in dystrophic muscle fibroblasts. • Canonical NF-κB pathway mediates these effects of TGF-β1.« less

Osteoprotegerin and β2-Agonists Mitigate Muscular Dystrophy in Slow- and Fast-Twitch Skeletal Muscles.

PubMed

Dufresne, Sébastien S; Boulanger-Piette, Antoine; Frenette, Jérôme

2017-03-01

Our recent work showed that daily injections of osteoprotegerin (OPG)-immunoglobulin fragment complex (OPG-Fc) completely restore the function of fast-twitch extensor digitorum longus muscles in dystrophic mdx mice, a murine model of Duchenne muscular dystrophy. However, despite marked improvements, OPG-Fc was not as effective in preventing the loss of function of slow-twitch soleus and diaphragm muscles. Because β 2 -agonists enhance the function of slow- and fast-twitch dystrophic muscles and because their use is limited by their adverse effects on bone and cardiac tissues, we hypothesized that OPG-Fc, a bone and skeletal muscle protector, acts synergistically with β 2 -agonists and potentiates their positive effects on skeletal muscles. We observed that the content of β 2 -adrenergic receptors, which are mainly expressed in skeletal muscle, is significantly reduced in dystrophic muscles but is rescued by the injection of OPG-Fc. Most important, OPG-Fc combined with a low dose of formoterol, a member of a new generation of β 2 -agonists, histologically and functionally rescued slow-twitch dystrophic muscles. This combination of therapeutic agents, which have already been tested and approved for human use, may open up new therapeutic avenues for Duchenne muscular dystrophy and possibly other neuromuscular diseases. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Respiratory infection with Francisella novicida induces rapid dystrophic cardiac calcinosis (DCC).

PubMed

Roth, Kimberly M; Oghumu, Steve; Satoskar, Anjali A; Gunn, John S; van Rooijen, Nico; Satoskar, Abhay R

2008-06-01

Francisella tularensis causes pulmonary tularemia and death in humans when left untreated. Here, using a novel aerosol infection model, we show that acute pulmonary Francisella novicida infection not only causes pneumonia and liver damage, but also induces dystrophic cardiac calcinosis (DCC) in BALB/c mice. C57BL/6 mice also develop pneumonia and hepatic damage, but fail to develop DCC. Development of DCC in BALB/c mice is associated with significant induction of RANKL but not osteopontin in their organs. Depletion of lung macrophages prior to infection markedly reduces pericarditis and calcification in BALB/c mice but does not increase their susceptibility to infection.

Humoral Immunity to AAV-6, 8, and 9 in Normal and Dystrophic Dogs

PubMed Central

Shin, Jin-Hong; Yue, Yongping; Smith, Bruce

2012-01-01

Abstract Adeno-associated virus (AAV)-6, 8, and 9 are promising gene-delivery vectors for testing novel Duchenne muscular dystrophy gene therapy in the canine model. Humoral immunity greatly influences in vivo AAV transduction. However, neutralizing antibodies to AAV-6, 8, and 9 have not been systemically examined in normal and dystrophic dogs. To gain information on the seroprevalence of antibodies to AAV-6, 8, and 9, we measured neutralizing antibody titers using an in vitro transduction inhibition assay. We examined 72 naive serum samples and 26 serum samples obtained from dogs that had received AAV gene transfer. Our data demonstrated that AAV-6 neutralizing antibody was the most prevalent antibody in dogs irrespective of age, gender, disease status (dystrophic or not), and prior parvovirus vaccination history. Surprisingly, high-level anti-AAV-6 antibody was detected at birth in newborn puppies. Further, a robust antibody response was induced in affected, but not normal newborn dogs following systemic AAV gene transfer. Taken together, our data have provided an important baseline on the seroprevalence of AAV-6, 8, and 9 neutralizing antibodies in normal and Duchenne muscular dystrophy dogs. These results will help guide translational AAV gene-therapy studies in dog models of muscular dystrophy. PMID:22040468

Muscle biopsies from human muscle diseases with myopathic pathology reveal common alterations in mitochondrial function.

PubMed

Sunitha, Balaraju; Gayathri, Narayanappa; Kumar, Manish; Keshava Prasad, Thottethodi Subrahmanya; Nalini, Atchayaram; Padmanabhan, Balasundaram; Srinivas Bharath, Muchukunte Mukunda

2016-07-01

Muscle diseases are clinically and genetically heterogeneous and manifest as dystrophic, inflammatory and myopathic pathologies, among others. Our previous study on the cardiotoxin mouse model of myodegeneration and inflammation linked muscle pathology with mitochondrial damage and oxidative stress. In this study, we investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies from muscle disease patients, represented by dysferlinopathy (dysfy) (dystrophic pathology; n = 43), polymyositis (PM) (inflammatory pathology; n = 24), and distal myopathy with rimmed vacuoles (DMRV) (distal myopathy; n = 31) were analyzed. Mitochondrial damage (ragged blue and COX-deficient fibers) was revealed in dysfy, PM, and DMRV cases by enzyme histochemistry (SDH and COX-SDH), electron microscopy (vacuolation and altered cristae) and biochemical assays (significantly increased ADP/ATP ratio). Proteomic analysis of muscle mitochondria from all three muscle diseases by isobaric tag for relative and absolute quantitation labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated down-regulation of electron transport chain (ETC) complex subunits, assembly factors and Krebs cycle enzymes. Interestingly, 80 of the under-expressed proteins were common among the three pathologies. Assay of ETC and Krebs cycle enzyme activities validated the MS data. Mitochondrial proteins from muscle pathologies also displayed higher tryptophan (Trp) oxidation and the same was corroborated in the cardiotoxin model. Molecular modeling predicted Trp oxidation to alter the local structure of mitochondrial proteins. Our data highlight mitochondrial alterations in muscle pathologies, represented by morphological changes, altered mitochondrial proteome and protein oxidation, thereby establishing the role of mitochondrial damage in human muscle diseases. We investigated whether human muscle diseases display mitochondrial changes. Muscle biopsies from dysferlinopathy (Dysfy), polymyositis (PM), and distal myopathy with rimmed vacuoles (DMRV) displayed morphological and biochemical evidences of mitochondrial dysfunction. Proteomic analysis revealed down-regulation of electron transport chain (ETC) subunits, assembly factors, and tricarboxylic acid (TCA) cycle enzymes, with 80 proteins common among the three pathologies. Mitochondrial proteins from muscle pathologies also displayed higher Trp oxidation that could alter the local structure. Cover image for this issue: doi: 10.1111/jnc.13324. © 2016 International Society for Neurochemistry.

Mechanical characterization of the mouse diaphragm with optical coherence elastography reveals fibrosis-related change of direction-dependent muscle tissue stiffness

NASA Astrophysics Data System (ADS)

Wang, Shang; Loehr, James A.; Larina, Irina V.; Rodney, George G.; Larin, Kirill V.

2016-03-01

The diaphragm, composed of skeletal muscle, plays an important role in respiration through its dynamic contraction. Genetic and molecular studies of the biomechanics of mouse diaphragm can provide great insights into an improved understanding and potential treatment of the disorders that lead to diaphragm dysfunction (i.e. muscular dystrophy). However, due to the small tissue size, mechanical assessment of mouse diaphragm tissue under its proper physiological conditions has been challenging. Here, we present the application of noncontact optical coherence elastography (OCE) for quantitative elastic characterization of ex vivo mouse diaphragm. Phase-sensitive optical coherence tomography was combined with a focused air-puff system to capture and measure the elastic wave propagation from tissue surface. Experiments were performed on wildtype and dystrophic mouse diaphragm tissues containing different levels of fibrosis. The OCE measurements of elastic wave propagation were conducted along both the longitudinal and transverse axis of the muscle fibers. Cross-correlation of the temporal displacement profiles from different spatial locations was utilized to obtain the propagation time delay, which was used to calculate the wave group velocity and to further quantify the tissue Young's modulus. Prior to and after OCE assessment, peak tetanic force was measured to monitor viability of the tissue during the elasticity measurements. Our experimental results indicate a positive correlation between fibrosis level and tissue stiffness, suggesting this elastic-wave-based OCE method could be a useful tool to monitor mechanical properties of skeletal muscle under physiological and pathological conditions.

Adaptive Immune Response Impairs the Efficacy of Autologous Transplantation of Engineered Stem Cells in Dystrophic Dogs

PubMed Central

Sitzia, Clementina; Farini, Andrea; Jardim, Luciana; Razini, Paola; Belicchi, Marzia; Cassinelli, Letizia; Villa, Chiara; Erratico, Silvia; Parolini, Daniele; Bella, Pamela; da Silva Bizario, Joao Carlos; Garcia, Luis; Dias-Baruffi, Marcelo; Meregalli, Mirella; Torrente, Yvan

2016-01-01

Duchenne muscular dystrophy is the most common genetic muscular dystrophy. It is caused by mutations in the dystrophin gene, leading to absence of muscular dystrophin and to progressive degeneration of skeletal muscle. We have demonstrated that the exon skipping method safely and efficiently brings to the expression of a functional dystrophin in dystrophic CD133+ cells injected scid/mdx mice. Golden Retriever muscular dystrophic (GRMD) dogs represent the best preclinical model of Duchenne muscular dystrophy, mimicking the human pathology in genotypic and phenotypic aspects. Here, we assess the capacity of intra-arterial delivered autologous engineered canine CD133+ cells of restoring dystrophin expression in Golden Retriever muscular dystrophy. This is the first demonstration of five-year follow up study, showing initial clinical amelioration followed by stabilization in mild and severe affected Golden Retriever muscular dystrophy dogs. The occurrence of T-cell response in three Golden Retriever muscular dystrophy dogs, consistent with a memory response boosted by the exon skipped-dystrophin protein, suggests an adaptive immune response against dystrophin. PMID:27506452

Proteomic profiling of early degenerative retina of RCS rats.

PubMed

Zhu, Zhi-Hong; Fu, Yan; Weng, Chuan-Huang; Zhao, Cong-Jian; Yin, Zheng-Qin

2017-01-01

To identify the underlying cellular and molecular changes in retinitis pigmentosa (RP). Label-free quantification-based proteomics analysis, with its advantages of being more economic and consisting of simpler procedures, has been used with increasing frequency in modern biological research. Dystrophic RCS rats, the first laboratory animal model for the study of RP, possess a similar pathological course as human beings with the diseases. Thus, we employed a comparative proteomics analysis approach for in-depth proteome profiling of retinas from dystrophic RCS rats and non-dystrophic congenic controls through Linear Trap Quadrupole - orbitrap MS/MS, to identify the significant differentially expressed proteins (DEPs). Bioinformatics analyses, including Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation and upstream regulatory analysis, were then performed on these retina proteins. Finally, a Western blotting experiment was carried out to verify the difference in the abundance of transcript factor E2F1. In this study, we identified a total of 2375 protein groups from the retinal protein samples of RCS rats and non-dystrophic congenic controls. Four hundred thirty-four significantly DEPs were selected by Student's t -test. Based on the results of the bioinformatics analysis, we identified mitochondrial dysfunction and transcription factor E2F1 as the key initiation factors in early retinal degenerative process. We showed that the mitochondrial dysfunction and the transcription factor E2F1 substantially contribute to the disease etiology of RP. The results provide a new potential therapeutic approach for this retinal degenerative disease.

Engraftment potential of dermal fibroblasts following in vivo myogenic conversion in immunocompetent dystrophic skeletal muscle

PubMed Central

Muir, Lindsey A; Nguyen, Quynh G; Hauschka, Stephen D; Chamberlain, Jeffrey S

2014-01-01

Autologous dermal fibroblasts (dFbs) are promising candidates for enhancing muscle regeneration in Duchenne muscular dystrophy (DMD) due to their ease of isolation, immunological compatibility, and greater proliferative potential than DMD satellite cells. We previously showed that mouse fibroblasts, after MyoD-mediated myogenic reprogramming in vivo, engraft in skeletal muscle and supply dystrophin. Assessing the therapeutic utility of this system requires optimization of conversion and transplantation conditions and quantitation of engraftment so that these parameters can be correlated with possible functional improvements. Here, we derived dFbs from transgenic mice carrying mini-dystrophin, transduced them by lentivirus carrying tamoxifen-inducible MyoD, and characterized their myogenic and engraftment potential. After cell transplantation into the muscles of immunocompetent dystrophic mdx4cv mice, tamoxifen treatment drove myogenic conversion and fusion into myofibers that expressed high levels of mini-dystrophin. Injecting 50,000 cells/µl (1 × 106 total cells) resulted in a peak of ~600 mini-dystrophin positive myofibers in tibialis anterior muscle single cross-sections. However, extensor digitorum longus muscles with up to 30% regional engraftment showed no functional improvements; similar limitations were obtained with whole muscle mononuclear cells. Despite the current lack of physiological improvement, this study suggests a viable initial strategy for using a patient-accessible dermal cell population to enhance skeletal muscle regeneration in DMD. PMID:25558461

Cardiomyopathy in Patients With Hereditary Bullous Epidermolysis.

PubMed

Batalla, A; Vicente, A; Bartrons, J; Prada, F; Fortuny, C; González-Enseñat, M A

In recent decades, an association has been reported between epidermolysis bullosa (EB) and dilated cardiomyopathy (DC). DC is typically in an advanced phase when detected, leading to a poorer prognosis. Our objective was to determine the prevalence of DC in patients with EB seen in Hospital San Joan de Déu in Barcelona, Spain, between May 1986 and April 2015. This was a descriptive, cross-sectional chart-review study in which we recorded the type and main subtypes of EB and the presence or absence of DC. Fifty-seven patients with EB were found, 19 with EB simplex, 10 with junctional EB, 27 with dystrophic EB (14 dominant dystrophic and 13 recessive dystrophic), and just 1 with Kindler syndrome. DC was detected in only 2 patients with recessive dystrophic EB. Twenty-three patients had presented factors that could have had a causal relationship with the potential onset of DC. DC is a possible complication of EB, particularly in recessive dystrophic EB. Periodic follow-up should be performed to make an early diagnosis and start treatment. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Deletion of Galgt2 (B4Galnt2) Reduces Muscle Growth in Response to Acute Injury and Increases Muscle Inflammation and Pathology in Dystrophin-Deficient Mice

PubMed Central

Xu, Rui; Singhal, Neha; Serinagaoglu, Yelda; Chandrasekharan, Kumaran; Joshi, Mandar; Bauer, John A.; Janssen, Paulus M.L.; Martin, Paul T.

2016-01-01

Transgenic overexpression of Galgt2 (official name B4Galnt2) in skeletal muscle stimulates the glycosylation of α dystroglycan (αDG) and the up-regulation of laminin α2 and dystrophin surrogates known to inhibit muscle pathology in mouse models of congenital muscular dystrophy 1A and Duchenne muscular dystrophy. Skeletal muscle Galgt2 gene expression is also normally increased in the mdx mouse model of Duchenne muscular dystrophy compared with the wild-type mice. To assess whether this increased endogenous Galgt2 expression could affect disease, we quantified muscular dystrophy measures in mdx mice deleted for Galgt2 (Galgt2−/−mdx). Galgt2−/− mdx mice had increased heart and skeletal muscle pathology and inflammation, and also worsened cardiac function, relative to age-matched mdx mice. Deletion of Galgt2 in wild-type mice also slowed skeletal muscle growth in response to acute muscle injury. In each instance where Galgt2 expression was elevated (developing muscle, regenerating muscle, and dystrophic muscle), Galgt2-dependent glycosylation of αDG was also increased. Overexpression of Galgt2 failed to inhibit skeletal muscle pathology in dystroglycan-deficient muscles, in contrast to previous studies in dystrophin-deficient mdx muscles. This study demonstrates that Galgt2 gene expression and glycosylation of αDG are dynamically regulated in muscle and that endogenous Galgt2 gene expression can ameliorate the extent of muscle pathology, inflammation, and dysfunction in mdx mice. PMID:26435413

Chronic Dosing with Membrane Sealant Poloxamer 188 NF Improves Respiratory Dysfunction in Dystrophic Mdx and Mdx/Utrophin-/- Mice.

PubMed

Markham, Bruce E; Kernodle, Stace; Nemzek, Jean; Wilkinson, John E; Sigler, Robert

2015-01-01

Poloxamer 188 NF (national formulary (NF) grade of P-188) improves cardiac muscle function in the mdx mouse and golden retriever muscular dystrophy models. However in vivo effects on skeletal muscle have not been reported. We postulated that P-188 NF might protect diaphragm muscle membranes from contraction-induced injury in mdx and mdx/utrophin-/- (dko) muscular dystrophy models. In the first study 7-month old mdx mice were treated for 22 weeks with subcutaneous (s.c.) injections of saline or P-188 NF at 3 mg/Kg. In the second, dkos were treated with saline or P-188 NF (1 mg/Kg) for 8 weeks beginning at age 3 weeks. Prednisone was the positive control in both studies. Respiratory function was monitored using unrestrained whole body plethysmography. P-188 NF treatment affected several respiratory parameters including tidal volume/BW and minute volume/BW in mdx mice. In the more severe dko model, P-188 NF (1 mg/Kg) significantly slowed the decline in multiple respiratory parameters compared with saline-treated dko mice. Prednisone's effects were similar to those seen with P-188 NF. Diaphragms from P-188 NF or prednisone treated mdx and dko mice showed signs of muscle fiber protection including less centralized nuclei, less variation in fiber size, greater fiber density, and exhibited a decreased amount of collagen deposition. P-188 NF at 3 mg/Kg s.c. also improved parameters of systolic and diastolic function in mdx mouse hearts. These results suggest that P-188 NF may be useful in treating respiratory and cardiac dysfunction, the leading causes of death in Duchenne muscular dystrophy patients.

Chronic Dosing with Membrane Sealant Poloxamer 188 NF Improves Respiratory Dysfunction in Dystrophic Mdx and Mdx/Utrophin-/- Mice

PubMed Central

Markham, Bruce E.; Kernodle, Stace; Nemzek, Jean; Wilkinson, John E.; Sigler, Robert

2015-01-01

Poloxamer 188 NF (national formulary (NF) grade of P-188) improves cardiac muscle function in the mdx mouse and golden retriever muscular dystrophy models. However in vivo effects on skeletal muscle have not been reported. We postulated that P-188 NF might protect diaphragm muscle membranes from contraction-induced injury in mdx and mdx/utrophin-/- (dko) muscular dystrophy models. In the first study 7-month old mdx mice were treated for 22 weeks with subcutaneous (s.c.) injections of saline or P-188 NF at 3 mg/Kg. In the second, dkos were treated with saline or P-188 NF (1 mg/Kg) for 8 weeks beginning at age 3 weeks. Prednisone was the positive control in both studies. Respiratory function was monitored using unrestrained whole body plethysmography. P-188 NF treatment affected several respiratory parameters including tidal volume/BW and minute volume/BW in mdx mice. In the more severe dko model, P-188 NF (1 mg/Kg) significantly slowed the decline in multiple respiratory parameters compared with saline-treated dko mice. Prednisone’s effects were similar to those seen with P-188 NF. Diaphragms from P-188 NF or prednisone treated mdx and dko mice showed signs of muscle fiber protection including less centralized nuclei, less variation in fiber size, greater fiber density, and exhibited a decreased amount of collagen deposition. P-188 NF at 3 mg/Kg s.c. also improved parameters of systolic and diastolic function in mdx mouse hearts. These results suggest that P-188 NF may be useful in treating respiratory and cardiac dysfunction, the leading causes of death in Duchenne muscular dystrophy patients. PMID:26248188

Genetic Evaluation for the Scoliosis Gene(s) in Patients with Neurofibromatosis 1 and Scoliosis

DTIC Science & Technology

2015-10-01

AWARD NUMBER: W81XWH-10-1-0469 TITLE: Genetic Evaluation for the Scoliosis Gene(s) in Patients with Neurofibromatosis 1 and Scoliosis...31Jul2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER "Genetic Evaluation for the Scoliosis Gene(s) in Patients with Neurofibromatosis 1 and Scoliosis." 5b...ABSTRACT Dystrophic or non-dystrophic forms of scoliosis are skeletal manifestations of Neurofibromatosis type 1 (NF1). Dystrophic scoliosis has a more

Resveratrol induces expression of the slow, oxidative phenotype in mdx mouse muscle together with enhanced activity of the SIRT1-PGC-1α axis.

PubMed

Ljubicic, Vladimir; Burt, Matthew; Lunde, John A; Jasmin, Bernard J

2014-07-01

Slower, more oxidative muscle fibers are more resistant to the dystrophic pathology in Duchenne muscular dystrophy (DMD) patients as well as in the preclinical mdx mouse model of DMD. Therefore, one therapeutic strategy for DMD focuses on promoting expression of the slow, oxidative myogenic program. In the current study, we explored the therapeutic potential of stimulating the slow, oxidative phenotype in mdx mice by feeding 6-wk-old animals with the natural phenol resveratrol (RSV; ~100 mg·kg(-1)·day(-1)) for 6 wk. Sirtuin 1 (SIRT1) activity and protein levels increased significantly, as well as peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) activity, in the absence of alterations in AMPK signaling. These adaptations occurred concomitant with evidence of a fast, glycolytic, to slower, more oxidative fiber type conversion, including mitochondrial biogenesis and increased expression of slower myosin heavy chain isoforms. These positive findings raised the question of whether increased exposure to RSV would result in greater therapeutic benefits. We discovered that an elevated RSV dose of ~500 mg·kg(-1)·day(-1) across a duration of 12 wk was clearly less effective at muscle remodeling in mdx mice. This treatment protocol failed to influence SIRT1 or AMPK signaling and did not result in a shift towards a slower, more oxidative phenotype. Taken together, this study demonstrates that RSV can stimulate SIRT1 and PGC-1α activation, which in turn may promote expression of the slow, oxidative myogenic program in mdx mouse muscle. The data also highlight the importance of selecting an appropriate dosage regimen of RSV to maximize its potential therapeutic effectiveness for future application in DMD patients. Copyright © 2014 the American Physiological Society.

Resveratrol induces expression of the slow, oxidative phenotype in mdx mouse muscle together with enhanced activity of the SIRT1-PGC-1α axis

PubMed Central

Ljubicic, Vladimir; Burt, Matthew; Lunde, John A.

2014-01-01

Slower, more oxidative muscle fibers are more resistant to the dystrophic pathology in Duchenne muscular dystrophy (DMD) patients as well as in the preclinical mdx mouse model of DMD. Therefore, one therapeutic strategy for DMD focuses on promoting expression of the slow, oxidative myogenic program. In the current study, we explored the therapeutic potential of stimulating the slow, oxidative phenotype in mdx mice by feeding 6-wk-old animals with the natural phenol resveratrol (RSV; ∼100 mg·kg−1·day−1) for 6 wk. Sirtuin 1 (SIRT1) activity and protein levels increased significantly, as well as peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) activity, in the absence of alterations in AMPK signaling. These adaptations occurred concomitant with evidence of a fast, glycolytic, to slower, more oxidative fiber type conversion, including mitochondrial biogenesis and increased expression of slower myosin heavy chain isoforms. These positive findings raised the question of whether increased exposure to RSV would result in greater therapeutic benefits. We discovered that an elevated RSV dose of ∼500 mg·kg−1·day−1 across a duration of 12 wk was clearly less effective at muscle remodeling in mdx mice. This treatment protocol failed to influence SIRT1 or AMPK signaling and did not result in a shift towards a slower, more oxidative phenotype. Taken together, this study demonstrates that RSV can stimulate SIRT1 and PGC-1α activation, which in turn may promote expression of the slow, oxidative myogenic program in mdx mouse muscle. The data also highlight the importance of selecting an appropriate dosage regimen of RSV to maximize its potential therapeutic effectiveness for future application in DMD patients. PMID:24760981

Absence of microRNA-21 does not reduce muscular dystrophy in mouse models of LAMA2-CMD.

PubMed

Moreira Soares Oliveira, Bernardo; Durbeej, Madeleine; Holmberg, Johan

2017-01-01

MicroRNAs (miRNAs) are short non-coding RNAs that modulate gene expression post-transcriptionally. Current evidence suggests that miR-21 plays a significant role in the progression of fibrosis in muscle diseases. Laminin-deficient congenital muscular dystrophy (LAMA2-CMD) is a severe form of congenital muscular dystrophy caused by mutations in the gene encoding laminin α2 chain. Mouse models dy3K/dy3K and dy2J/dy2J, respectively, adequately mirror severe and milder forms of LAMA2-CMD. Both human and mouse LAMA2-CMD muscles are characterized by extensive fibrosis and considering that fibrosis is the final step that destroys muscle during the disease course, anti-fibrotic therapies may be effective strategies for prevention of LAMA2-CMD. We have previously demonstrated a significant up-regulation of the pro-fibrotic miR-21 in dy3K/dy3K and dy2J/dy2J skeletal muscle. Hence, the objective of this study was to explore if absence of miR-21 reduces fibrogenesis and improves the phenotype of LAMA2-CMD mice. Thus, we generated dy3K/dy3K and dy2J/dy2J mice devoid of miR-21 (dy3K/miR-21 and dy2J/miR-21 mice, respectively). However, the muscular dystrophy phenotype of dy3K/miR-21 and dy2J/miR-21 double knock-out mice was not improved compared to dy3K/dy3K or dy2J/dy2J mice, respectively. Mice displayed the same body weight, dystrophic muscles (with fibrosis) and impaired muscle function. These data indicate that miR-21 may not be involved in the development of fibrosis in LAMA2-CMD.

Genetic silencing of Nrf2 enhances X-ROS in dysferlin-deficient muscle

PubMed Central

Kombairaju, Ponvijay; Kerr, Jaclyn P.; Roche, Joseph A.; Pratt, Stephen J. P.; Lovering, Richard M.; Sussan, Thomas E.; Kim, Jung-Hyun; Shi, Guoli; Biswal, Shyam; Ward, Christopher W.

2014-01-01

Oxidative stress is a critical disease modifier in the muscular dystrophies. Recently, we discovered a pathway by which mechanical stretch activates NADPH Oxidase 2 (Nox2) dependent ROS generation (X-ROS). Our work in dystrophic skeletal muscle revealed that X-ROS is excessive in dystrophin-deficient (mdx) skeletal muscle and contributes to muscle injury susceptibility, a hallmark of the dystrophic process. We also observed widespread alterations in the expression of genes associated with the X-ROS pathway and redox homeostasis in muscles from both Duchenne muscular dystrophy patients and mdx mice. As nuclear factor erythroid 2-related factor 2 (Nrf2) plays an essential role in the transcriptional regulation of genes involved in redox homeostasis, we hypothesized that Nrf2 deficiency may contribute to enhanced X-ROS signaling by reducing redox buffering. To directly test the effect of diminished Nrf2 activity, Nrf2 was genetically silenced in the A/J model of dysferlinopathy—a model with a mild histopathologic and functional phenotype. Nrf2-deficient A/J mice exhibited significant muscle-specific functional deficits, histopathologic abnormalities, and dramatically enhanced X-ROS compared to control A/J and WT mice, both with functional Nrf2. Having identified that reduced Nrf2 activity is a negative disease modifier, we propose that strategies targeting Nrf2 activation may address the generalized reduction in redox homeostasis to halt or slow dystrophic progression. PMID:24600403

Proteomic profiling of early degenerative retina of RCS rats

PubMed Central

Zhu, Zhi-Hong; Fu, Yan; Weng, Chuan-Huang; Zhao, Cong-Jian; Yin, Zheng-Qin

2017-01-01

AIM To identify the underlying cellular and molecular changes in retinitis pigmentosa (RP). METHODS Label-free quantification-based proteomics analysis, with its advantages of being more economic and consisting of simpler procedures, has been used with increasing frequency in modern biological research. Dystrophic RCS rats, the first laboratory animal model for the study of RP, possess a similar pathological course as human beings with the diseases. Thus, we employed a comparative proteomics analysis approach for in-depth proteome profiling of retinas from dystrophic RCS rats and non-dystrophic congenic controls through Linear Trap Quadrupole - orbitrap MS/MS, to identify the significant differentially expressed proteins (DEPs). Bioinformatics analyses, including Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation and upstream regulatory analysis, were then performed on these retina proteins. Finally, a Western blotting experiment was carried out to verify the difference in the abundance of transcript factor E2F1. RESULTS In this study, we identified a total of 2375 protein groups from the retinal protein samples of RCS rats and non-dystrophic congenic controls. Four hundred thirty-four significantly DEPs were selected by Student's t-test. Based on the results of the bioinformatics analysis, we identified mitochondrial dysfunction and transcription factor E2F1 as the key initiation factors in early retinal degenerative process. CONCLUSION We showed that the mitochondrial dysfunction and the transcription factor E2F1 substantially contribute to the disease etiology of RP. The results provide a new potential therapeutic approach for this retinal degenerative disease. PMID:28730077

Glucocorticoids enhance muscle endurance and ameliorate Duchenne muscular dystrophy through a defined metabolic program.

PubMed

Morrison-Nozik, Alexander; Anand, Priti; Zhu, Han; Duan, Qiming; Sabeh, Mohamad; Prosdocimo, Domenick A; Lemieux, Madeleine E; Nordsborg, Nikolai; Russell, Aaron P; MacRae, Calum A; Gerber, Anthony N; Jain, Mukesh K; Haldar, Saptarsi M

2015-12-08

Classic physiology studies dating to the 1930s demonstrate that moderate or transient glucocorticoid (GC) exposure improves muscle performance. The ergogenic properties of GCs are further evidenced by their surreptitious use as doping agents by endurance athletes and poorly understood efficacy in Duchenne muscular dystrophy (DMD), a genetic muscle-wasting disease. A defined molecular basis underlying these performance-enhancing properties of GCs in skeletal muscle remains obscure. Here, we demonstrate that ergogenic effects of GCs are mediated by direct induction of the metabolic transcription factor KLF15, defining a downstream pathway distinct from that resulting in GC-related muscle atrophy. Furthermore, we establish that KLF15 deficiency exacerbates dystrophic severity and muscle GC-KLF15 signaling mediates salutary therapeutic effects in the mdx mouse model of DMD. Thus, although glucocorticoid receptor (GR)-mediated transactivation is often associated with muscle atrophy and other adverse effects of pharmacologic GC administration, our data define a distinct GR-induced gene regulatory pathway that contributes to therapeutic effects of GCs in DMD through proergogenic metabolic programming.

Regulatory T cells suppress muscle inflammation and injury in muscular dystrophy.

PubMed

Villalta, S Armando; Rosenthal, Wendy; Martinez, Leonel; Kaur, Amanjot; Sparwasser, Tim; Tidball, James G; Margeta, Marta; Spencer, Melissa J; Bluestone, Jeffrey A

2014-10-15

We examined the hypothesis that regulatory T cells (Tregs) modulate muscle injury and inflammation in the mdx mouse model of Duchenne muscular dystrophy (DMD). Although Tregs were largely absent in the muscle of wild-type mice and normal human muscle, they were present in necrotic lesions, displayed an activated phenotype, and showed increased expression of interleukin-10 (IL-10) in dystrophic muscle from mdx mice. Depletion of Tregs exacerbated muscle injury and the severity of muscle inflammation, which was characterized by an enhanced interferon-γ (IFN-γ) response and activation of M1 macrophages. To test the therapeutic value of targeting Tregs in muscular dystrophy, we treated mdx mice with IL-2/anti-IL-2 complexes and found that Tregs and IL-10 concentrations were increased in muscle, resulting in reduced expression of cyclooxygenase-2 and decreased myofiber injury. These findings suggest that Tregs modulate the progression of muscular dystrophy by suppressing type 1 inflammation in muscle associated with muscle fiber injury, and highlight the potential of Treg-modulating agents as therapeutics for DMD. Copyright © 2014, American Association for the Advancement of Science.

Prophylactic pamidronate partially protects from glucocorticoid-induced bone loss in the mdx mouse model of Duchenne muscular dystrophy.

PubMed

Yoon, Sung-Hee; Chen, Jinghan; Grynpas, Marc D; Mitchell, Jane

2016-09-01

Glucocorticoids are extensively used to treat patients with Duchenne muscular dystrophy because of their ability to delay muscle damage, prolong ambulation and extend life. However, use of glucocorticoids significantly increases bone loss, fragility and fractures. To determine if antiresorptive bisphosphonates could prevent the effects of glucocorticoids on bone quality, we used dystrophic mdx mice treated with the glucocorticoid prednisone during 8weeks of rapid bone growth from 5 to 13weeks of age and treated some mice with the bisphosphonate pamidronate during the first two weeks of prednisone administration. Prednisone reduced long bone growth, decreased cortical bone thickness and area and decreased the strength of the femurs. Pamidronate treatment protected mice from cortical bone loss but did not increase bone strength. The combination of prednisone and pamidronate inhibited remodeling of metaphyseal trabecular bone with large numbers of trabeculae containing remnants of calcified cartilage. Prednisone improved muscle strength in the mdx mice and decreased serum creatine kinase with evidence of improved muscle histology and these effects were maintained in mice treated with pamidronate. Copyright © 2016. Published by Elsevier Inc.

Regulatory T cells suppress muscle inflammation and injury in muscular dystrophy

PubMed Central

Villalta, S. Armando; Rosenthal, Wendy; Martinez, Leonel; Kaur, Amanjot; Sparwasser, Tim; Tidball, James G.; Margeta, Marta; Spencer, Melissa J.; Bluestone, Jeffrey A.

2016-01-01

We examined the hypothesis that regulatory T cells (Tregs) modulate muscle injury and inflammation in the mdx mouse model of Duchenne muscular dystrophy (DMD). Although Tregs were largely absent in the muscle of wildtype mice and normal human muscle, they were present in necrotic lesions, displayed an activated phenotype and showed increased expression of interleukin (IL)-10 in dystrophic muscle from mdx mice. Depletion of Tregs exacerbated muscle injury and the severity of muscle inflammation, which was characterized by an enhanced interferon-gamma (IFNγ) response and activation of M1 macrophages. To test the therapeutic value of targeting Tregs in muscular dystrophy, we treated mdx mice with IL-2/anti-IL-2 complexes (IL-2c), and found that Tregs and IL-10 concentrations were increased in muscle, resulting in reduced expression of cyclooygenase-2 and decreased myofiber injury. These findings suggest that Tregs modulate the progression of muscular dystrophy by suppressing type 1 inflammation in muscle associated with muscle fiber injury, and highlight the potential of Treg-modulating agents as therapeutics for DMD. PMID:25320234

Antisense pre-treatment increases gene therapy efficacy in dystrophic muscles.

PubMed

Peccate, Cécile; Mollard, Amédée; Le Hir, Maëva; Julien, Laura; McClorey, Graham; Jarmin, Susan; Le Heron, Anita; Dickson, George; Benkhelifa-Ziyyat, Sofia; Piétri-Rouxel, France; Wood, Matthew J; Voit, Thomas; Lorain, Stéphanie

2016-08-15

In preclinical models for Duchenne muscular dystrophy, dystrophin restoration during adeno-associated virus (AAV)-U7-mediated exon-skipping therapy was shown to decrease drastically after six months in treated muscles. This decline in efficacy is strongly correlated with the loss of the therapeutic AAV genomes, probably due to alterations of the dystrophic myofiber membranes. To improve the membrane integrity of the dystrophic myofibers at the time of AAV-U7 injection, mdx muscles were pre-treated with a single dose of the peptide-phosphorodiamidate morpholino (PPMO) antisense oligonucleotides that induced temporary dystrophin expression at the sarcolemma. The PPMO pre-treatment allowed efficient maintenance of AAV genomes in mdx muscles and enhanced the AAV-U7 therapy effect with a ten-fold increase of the protein level after 6 months. PPMO pre-treatment was also beneficial to AAV-mediated gene therapy with transfer of micro-dystrophin cDNA into muscles. Therefore, avoiding vector genome loss after AAV injection by PPMO pre-treatment would allow efficient long-term restoration of dystrophin and the use of lower and thus safer vector doses for Duchenne patients. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A novel mechanism of autophagic cell death in dystrophic muscle regulated by P2RX7 receptor large-pore formation and HSP90.

PubMed

Young, Christopher N J; Sinadinos, Anthony; Lefebvre, Alexis; Chan, Philippe; Arkle, Stephen; Vaudry, David; Gorecki, Dariusz C

2015-01-01

P2RX7 is an ATP-gated ion channel, which can also exhibit an open state with a considerably wider permeation. However, the functional significance of the movement of molecules through the large pore (LP) and the intracellular signaling events involved are not known. Here, analyzing the consequences of P2RX7 activation in primary myoblasts and myotubes from the Dmd(mdx) mouse model of Duchenne muscular dystrophy, we found ATP-induced P2RX7-dependent autophagic flux, leading to CASP3-CASP7-independent cell death. P2RX7-evoked autophagy was triggered by LP formation but not Ca(2+) influx or MAPK1-MAPK3 phosphorylation, 2 canonical P2RX7-evoked signals. Phosphoproteomics, protein expression inference and signaling pathway prediction analysis of P2RX7 signaling mediators pointed to HSPA2 and HSP90 proteins. Indeed, specific HSP90 inhibitors prevented LP formation, LC3-II accumulation, and cell death in myoblasts and myotubes but not in macrophages. Pharmacological blockade or genetic ablation of p2rx7 also proved protective against ATP-induced death of muscle cells, as did inhibition of autophagy with 3-MA. The functional significance of the P2RX7 LP is one of the great unknowns of purinergic signaling. Our data demonstrate a novel outcome--autophagy--and show that molecules entering through the LP can be targeted to phagophores. Moreover, we show that in muscles but not in macrophages, autophagy is needed for the formation of this LP. Given that P2RX7-dependent LP and HSP90 are critically interacting in the ATP-evoked autophagic death of dystrophic muscles, treatments targeting this axis could be of therapeutic benefit in this debilitating and incurable form of muscular dystrophy.

Expression of Pannexin 1 and Pannexin 3 during skeletal muscle development, regeneration, and Duchenne muscular dystrophy.

PubMed

Pham, Tammy L; St-Pierre, Marie-Eve; Ravel-Chapuis, Aymeric; Parks, Tara E C; Langlois, Stéphanie; Penuela, Silvia; Jasmin, Bernard J; Cowan, Kyle N

2018-05-10

Pannexin 1 (Panx1) and Pannexin 3 (Panx3) are single membrane channels recently implicated in myogenic commitment, as well as myoblast proliferation and differentiation in vitro. However, their expression patterns during skeletal muscle development and regeneration had yet to be investigated. Here, we show that Panx1 levels increase during skeletal muscle development becoming highly expressed together with Panx3 in adult skeletal muscle. In adult mice, Panx1 and Panx3 were differentially expressed in fast- and slow-twitch muscles. We also report that Panx1/PANX1 and Panx3/PANX3 are co-expressed in mouse and human satellite cells, which play crucial roles in skeletal muscle regeneration. Interestingly, Panx1 and Panx3 levels were modulated in muscle degeneration/regeneration, similar to the pattern seen during skeletal muscle development. As Duchenne muscular dystrophy is characterized by skeletal muscle degeneration and impaired regeneration, we next used mild and severe mouse models of this disease and found a significant dysregulation of Panx1 and Panx3 levels in dystrophic skeletal muscles. Together, our results are the first demonstration that Panx1 and Panx3 are differentially expressed amongst skeletal muscle types with their levels being highly modulated during skeletal muscle development, regeneration, and dystrophy. These findings suggest that Panx1 and Panx3 channels may play important and distinct roles in healthy and diseased skeletal muscles. © 2018 Wiley Periodicals, Inc.

Loss of spatacsin function alters lysosomal lipid clearance leading to upper and lower motor neuron degeneration.

PubMed

Branchu, Julien; Boutry, Maxime; Sourd, Laura; Depp, Marine; Leone, Céline; Corriger, Alexandrine; Vallucci, Maeva; Esteves, Typhaine; Matusiak, Raphaël; Dumont, Magali; Muriel, Marie-Paule; Santorelli, Filippo M; Brice, Alexis; El Hachimi, Khalid Hamid; Stevanin, Giovanni; Darios, Frédéric

2017-06-01

Mutations in SPG11 account for the most common form of autosomal recessive hereditary spastic paraplegia (HSP), characterized by a gait disorder associated with various brain alterations. Mutations in the same gene are also responsible for rare forms of Charcot-Marie-Tooth (CMT) disease and progressive juvenile-onset amyotrophic lateral sclerosis (ALS). To elucidate the physiopathological mechanisms underlying these human pathologies, we disrupted the Spg11 gene in mice by inserting stop codons in exon 32, mimicking the most frequent mutations found in patients. The Spg11 knockout mouse developed early-onset motor impairment and cognitive deficits. These behavioral deficits were associated with progressive brain atrophy with the loss of neurons in the primary motor cortex, cerebellum and hippocampus, as well as with accumulation of dystrophic axons in the corticospinal tract. Spinal motor neurons also degenerated and this was accompanied by fragmentation of neuromuscular junctions and muscle atrophy. This new Spg11 knockout mouse therefore recapitulates the full range of symptoms associated with SPG11 mutations observed in HSP, ALS and CMT patients. Examination of the cellular alterations observed in this model suggests that the loss of spatacsin leads to the accumulation of lipids in lysosomes by perturbing their clearance from these organelles. Altogether, our results link lysosomal dysfunction and lipid metabolism to neurodegeneration and pinpoint a critical role of spatacsin in lipid turnover. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

High levels of sarcospan are well tolerated and act as a sarcolemmal stabilizer to address skeletal muscle and pulmonary dysfunction in DMD

PubMed Central

Gibbs, Elizabeth M.; Marshall, Jamie L.; Ma, Eva; Nguyen, Thien M.; Hong, Grace; Lam, Jessica S.; Spencer, Melissa J.

2016-01-01

Abstract Duchenne muscular dystrophy (DMD) is a genetic disorder that causes progressive muscle weakness, ultimately leading to early mortality in affected teenagers and young adults. Previous work from our lab has shown that a small transmembrane protein called sarcospan (SSPN) can enhance the recruitment of adhesion complex proteins to the cell surface. When human SSPN is expressed at three-fold levels in mdx mice, this increase in adhesion complex abundance improves muscle membrane stability, preventing many of the histopathological changes associated with DMD. However, expressing higher levels of human SSPN (ten-fold transgenic expression) causes a severe degenerative muscle phenotype in wild-type mice. Since SSPN-mediated stabilization of the sarcolemma represents a promising therapeutic strategy in DMD, it is important to determine whether SSPN can be introduced at high levels without toxicity. Here, we show that mouse SSPN (mSSPN) can be overexpressed at 30-fold levels in wild-type mice with no deleterious effects. In mdx mice, mSSPN overexpression improves dystrophic pathology and sarcolemmal stability. We show that these mice exhibit increased resistance to eccentric contraction-induced damage and reduced fatigue following exercise. mSSPN overexpression improved pulmonary function and reduced dystrophic histopathology in the diaphragm. Together, these results demonstrate that SSPN overexpression is well tolerated in mdx mice and improves sarcolemma defects that underlie skeletal muscle and pulmonary dysfunction in DMD. PMID:27798107

A chronic inflammatory response dominates the skeletal muscle molecular signature in dystrophin-deficient mdx mice.

PubMed

Porter, John D; Khanna, Sangeeta; Kaminski, Henry J; Rao, J Sunil; Merriam, Anita P; Richmonds, Chelliah R; Leahy, Patrick; Li, Jingjin; Guo, Wei; Andrade, Francisco H

2002-02-01

Mutations in dystrophin cause Duchenne muscular dystrophy (DMD), but absent dystrophin does not invariably cause necrosis in all muscles, life stages and species. Using DNA microarray, we established a molecular signature of dystrophinopathy in the mdx mouse, with evidence that secondary mechanisms are key contributors to pathogenesis. We used variability controls, adequate replicates and stringent analytic tools, including significance analysis of microarrays to estimate and manage false positive rates. In leg muscle, we identified 242 differentially expressed genes, >75% of which have not been previously reported as altered in human or animal dystrophies. Data provide evidence for coordinated activity of numerous components of a chronic inflammatory response, including cytokine and chemokine signaling, leukocyte adhesion and diapedesis, invasive cell type-specific markers, and complement system activation. Selective chemokine upregulation was confirmed by RT-PCR and immunoblot, and may be a key determinant of the nature of the inflammatory response in dystrophic muscle. Up-regulation of secreted phosphoprotein 1 (minopontin, osteopontin) mRNA and protein in dystrophic muscle identified a novel linkage between inflammatory cells and repair processes. Extracellular matrix genes were up-regulated in mdx to levels similar to those in DMD. Since, unlike DMD, mdx exhibits little fibrosis, data suggest that collagen regulation at post-transcriptional stages mediates extensive fibrosis in DMD. Taken together, these data identify a relatively neglected aspect of DMD, suggest new treatment avenues, and highlight the value of genome-wide profiling in study of complex disease processes.

Scanning electron microscopy of a blister roof in dystrophic epidermolysis bullosa*

PubMed Central

de Almeida Jr., Hiram Larangeira; Monteiro, Luciane; Silva, Ricardo Marques e; Rocha, Nara Moreira; Scheffer, Hans

2013-01-01

In dystrophic epidermolysis bullosa the genetic defect of anchoring fibrils leads to cleavage beneath the basement membrane, with its consequent loss. We performed scanning electron microscopy of an inverted blister roof of a case of dystrophic epidermolysis bullosa, confirmed by immunomapping and gene sequencing. With a magnification of 2000 times a net attached to the blister roof could be easily identified. This net was composed of intertwined flat fibers. With higher magnifications, different fiber sizes could be observed, some thin fibers measuring around 80 nm and thicker ones measuring between 200 and 300 nm. PMID:24474107

Motor Physical Therapy Affects Muscle Collagen Type I and Decreases Gait Speed in Dystrophin-Deficient Dogs

PubMed Central

Gaiad, Thaís P.; Araujo, Karla P. C.; Serrão, Júlio C.; Miglino, Maria A.; Ambrósio, Carlos Eduardo

2014-01-01

Golden Retriever Muscular Dystrophy (GRMD) is a dystrophin-deficient canine model genetically homologous to Duchenne Muscular Dystrophy (DMD) in humans. Muscular fibrosis secondary to cycles of degeneration/regeneration of dystrophic muscle tissue and muscular weakness leads to biomechanical adaptation that impairs the quality of gait. Physical therapy (PT) is one of the supportive therapies available for DMD, however, motor PT approaches have controversial recommendations and there is no consensus regarding the type and intensity of physical therapy. In this study we investigated the effect of physical therapy on gait biomechanics and muscular collagen deposition types I and III in dystrophin-deficient dogs. Two dystrophic dogs (treated dogs-TD) underwent a PT protocol of active walking exercise, 3×/week, 40 minutes/day, 12 weeks. Two dystrophic control dogs (CD) maintained their routine of activities of daily living. At t0 (pre) and t1 (post-physical therapy), collagen type I and III were assessed by immunohistochemistry and gait biomechanics were analyzed. Angular displacement of shoulder, elbow, carpal, hip, stifle and tarsal joint and vertical (Fy), mediolateral (Fz) and craniocaudal (Fx) ground reaction forces (GRF) were assessed. Wilcoxon test was used to verify the difference of biomechanical variables between t0 and t1, considering p<.05. Type I collagen of endomysium suffered the influence of PT, as well as gait speed that had decreased from t0 to t1 (p<.000). The PT protocol employed accelerates morphological alterations on dystrophic muscle and promotes a slower velocity of gait. Control dogs which maintained their routine of activities of daily living seem to have found a better balance between movement and preservation of motor function. PMID:24713872

Dystrophic cardiomyopathy: role of TRPV2 channels in stretch-induced cell damage.

PubMed

Lorin, Charlotte; Vögeli, Isabelle; Niggli, Ernst

2015-04-01

Duchenne muscular dystrophy (DMD), a degenerative pathology of skeletal muscle, also induces cardiac failure and arrhythmias due to a mutation leading to the lack of the protein dystrophin. In cardiac cells, the subsarcolemmal localization of dystrophin is thought to protect the membrane from mechanical stress. The absence of dystrophin results in an elevated stress-induced Ca2+ influx due to the inadequate functioning of several proteins, such as stretch-activated channels (SACs). Our aim was to investigate whether transient receptor potential vanilloid channels type 2 (TRPV2) form subunits of the dysregulated SACs in cardiac dystrophy. We defined the role of TRPV2 channels in the abnormal Ca2+ influx of cardiomyocytes isolated from dystrophic mdx mice, an established animal model for DMD. In dystrophic cells, western blotting showed that TRPV2 was two-fold overexpressed. While normally localized intracellularly, in myocytes from mdx mice TRPV2 channels were translocated to the sarcolemma and were prominent along the T-tubules, as indicated by immunocytochemistry. Membrane localization was confirmed by biotinylation assays. Furthermore, in mdx myocytes pharmacological modulators suggested an abnormal activity of TRPV2, which has a unique pharmacological profile among TRP channels. Confocal imaging showed that these compounds protected the cells from stress-induced abnormal Ca2+ signals. The involvement of TRPV2 in these signals was confirmed by specific pore-blocking antibodies and by small-interfering RNA ablation of TRPV2. Together, these results establish the involvement of TRPV2 in a stretch-activated calcium influx pathway in dystrophic cardiomyopathy, contributing to the defective cellular Ca2+ handling in this disease. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Treatment and prevention of chemotherapy-induced alopecia with PTH-CBD, a collagen-targeted parathyroid hormone analog, in a non-depilated mouse model

PubMed Central

Katikaneni, Ranjitha; Ponnapakkam, Tulasi; Matsushita, Osamu; Sakon, Joshua; Gensure, Robert

2014-01-01

Alopecia is a psychologically devastating complication of chemotherapy for which there is currently no effective therapy. PTH-CBD is a collagen-targeted parathyroid hormone analog that has shown promise as a therapy for alopecia disorders. To compare the efficacy of prophylactic versus therapeutic administration of PTH-CBD in chemotherapy-induced alopecia using a mouse model that mimics the cyclic chemotherapy dosing used clinically. C57BL/6J mice were treated with a single subcutaneous injection of PTH-CBD (320 mcg/kg) or vehicle control before or after hair loss developing from three courses of cyclophosphamide chemotherapy (50–150 mg/kg/week). Mice receiving chemotherapy alone developed hair loss and depigmentation over 6–12 months. Mice pretreated with PTH-CBD did not develop these changes and maintained a normal-appearing coat. Mice treated with PTH-CBD after development of hair loss showed a partial recovery. Observations of hair loss were confirmed quantitatively by gray scale analysis. Histological examination showed that in mice receiving chemotherapy alone, there were small, dystrophic hair follicles mostly in the catagen phase. Mice receiving PTH-CBD before chemotherapy showed a mix of normal-appearing telogen and anagen hair follicles with no evidence of dystrophy. Mice receiving PTH-CBD therapy after chemotherapy showed intermediate histological features. PTH-CBD was effective in both the prevention and the treatment of chemotherapy-induced alopecia in mice, but pretreatment appears to result in a better cosmetic outcome. PTH-CBD shows promise as an agent in the prevention of this complication of chemotherapy and improving the quality of life for cancer patients. PMID:24025564

Treatment and prevention of chemotherapy-induced alopecia with PTH-CBD, a collagen-targeted parathyroid hormone analog, in a non-depilated mouse model.

PubMed

Katikaneni, Ranjitha; Ponnapakkam, Tulasi; Matsushita, Osamu; Sakon, Joshua; Gensure, Robert

2014-01-01

Alopecia is a psychologically devastating complication of chemotherapy for which there is currently no effective therapy. PTH-CBD is a collagen-targeted parathyroid hormone analog that has shown promise as a therapy for alopecia disorders. This study compared the efficacy of prophylactic versus therapeutic administration of PTH-CBD in chemotherapy-induced alopecia using a mouse model that mimics the cyclic chemotherapy dosing used clinically. C57BL/6J mice were treated with a single subcutaneous injection of PTH-CBD (320 mcg/kg) or vehicle control before or after hair loss developing from three courses of cyclophosphamide chemotherapy (50-150 mg/kg/week). Mice receiving chemotherapy alone developed hair loss and depigmentation over 6-12 months. Mice pretreated with PTH-CBD did not develop these changes and maintained a normal-appearing coat. Mice treated with PTH-CBD after development of hair loss showed a partial recovery. Observations of hair loss were confirmed quantitatively by gray scale analysis. Histological examination showed that in mice receiving chemotherapy alone, there were small, dystrophic hair follicles mostly in the catagen phase. Mice receiving PTH-CBD before chemotherapy showed a mix of normal-appearing telogen and anagen hair follicles with no evidence of dystrophy. Mice receiving PTH-CBD therapy after chemotherapy showed intermediate histological features. PTH-CBD was effective in both the prevention and the treatment of chemotherapy-induced alopecia in mice, but pretreatment appears to result in a better cosmetic outcome. PTH-CBD shows promise as an agent in the prevention of this complication of chemotherapy and improving the quality of life for cancer patients.

Investigations into Retinal Pathology in the Early Stages of a Mouse Model of Alzheimer’s Disease

PubMed Central

Chidlow, Glyn; Wood, John P.M.; Manavis, Jim; Finnie, John; Casson, Robert J.

2016-01-01

There is increasing recognition that visual performance is impaired in early stages of Alzheimer’s disease (AD); however, no consensus exists as to the mechanisms underlying this visual dysfunction, in particular regarding the timing, nature, and extent of retinal versus cortical pathology. If retinal pathology presents sufficiently early, it offers great potential as a source of novel biomarkers for disease diagnosis. The current project utilized an array of immunochemical and molecular tools to perform a characterization of retinal pathology in the early stages of disease progression using a well-validated mouse model of AD (APPSWE/PS1ΔE9). Analytical endpoints included examination of aberrant amyloid and tau in the retina, quantification of any neuronal degeneration, delineation of cellular stress responses of neurons and particularly glial cells, and investigation of oxidative stress. Brain, eyes, and optic nerves were taken from transgenic and wild-type mice of 3 to 12 months of age and processed for immunohistochemistry, qPCR, or western immunoblotting. The results revealed robust expression of the human APP transgene in the retinas of transgenic mice, but a lack of identifiable retinal pathology during the period when amyloid deposits were dramatically escalating in the brain. We were unable to demonstrate the presence of amyloid plaques, dystrophic neurites, neuronal loss, macro- or micro-gliosis, aberrant cell cycle re-entry, oxidative stress, tau hyperphosphorylation, or upregulations of proinflammatory cytokines or stress signaling molecules in the retina. The overall results do not support the hypothesis that detectable retinal pathology occurs concurrently with escalating amyloid deposition in the brains of APPSWE/PS1ΔE9 mice. PMID:28035930

Dystrophic calcification of the prostate after cryotherapy.

PubMed

Dru, Christopher; Bender, Leon

2014-01-01

We present a previously undocumented complication of dystrophic calcification of the prostate after cryotherapy. An 87-year-old male presented with recurrent lower urinary tract infections and was found to have an obstructing large calcified mass in the right lobe of the prostate. Subsequently, he underwent transurethral resection of the prostate (TURP) and bladder neck with laser lithotripsy to remove the calculus. We propose that chronic inflammation and necrosis of the prostate from cryotherapy resulted in dystrophic calcification of the prostate. As the use of cryotherapy for the treatment of localized prostate cancer continues to increase, it is important that clinicians be aware of this scenario and the technical challenges it poses.

Axonopathy in an α-Synuclein Transgenic Model of Lewy Body Disease Is Associated with Extensive Accumulation of C-Terminal–Truncated α-Synuclein

PubMed Central

Games, Dora; Seubert, Peter; Rockenstein, Edward; Patrick, Christina; Trejo, Margarita; Ubhi, Kiren; Ettle, Benjamin; Ghassemiam, Majid; Barbour, Robin; Schenk, Dale; Nuber, Silke; Masliah, Eliezer

2014-01-01

Progressive accumulation of α-synuclein (α-syn) in limbic and striatonigral systems is associated with the neurodegenerative processes in dementia with Lewy bodies (DLB) and Parkinson’s disease (PD). The murine Thy-1 (mThy1)-α-syn transgenic (tg) model recapitulates aspects of degenerative processes associated with α-syn accumulation in these disorders. Given that axonal and synaptic pathologies are important features of DLB and PD, we sought to investigate the extent and characteristics of these alterations in mThy1-α-syn tg mice and to determine the contribution of α-syn c-terminally cleaved at amino acid 122 (CT α-syn) to these abnormalities. We generated a novel polyclonal antibody (SYN105) against the c-terminally truncated sequence (amino acids 121 to 123) of α-syn (CT α-syn) and performed immunocytochemical and ultrastructural analyses in mThy1-α-syn tg mice. We found abundant clusters of dystrophic neurites in layers 2 to 3 of the neocortex, the stratum lacunosum, the dentate gyrus, and cornu ammonis 3 of the hippocampus, striatum, thalamus, midbrain, and pons. Dystrophic neurites displayed intense immunoreactivity detected with the SYN105 antibody. Double-labeling studies with antibodies to phosphorylated neurofilaments confirmed the axonal location of full-length and CT α-syn. α-Syn immunoreactive dystrophic neurites contained numerous electrodense laminated structures. These results show that neuritic dystrophy is a prominent pathologic feature of the mThy1-α-syn tg model and suggest that CT α-syn might play an important role in the process of axonal damage in these mice as well as in DLB and PD. PMID:23313024

Axonopathy in an α-synuclein transgenic model of Lewy body disease is associated with extensive accumulation of C-terminal-truncated α-synuclein.

PubMed

Games, Dora; Seubert, Peter; Rockenstein, Edward; Patrick, Christina; Trejo, Margarita; Ubhi, Kiren; Ettle, Benjamin; Ghassemiam, Majid; Barbour, Robin; Schenk, Dale; Nuber, Silke; Masliah, Eliezer

2013-03-01

Progressive accumulation of α-synuclein (α-syn) in limbic and striatonigral systems is associated with the neurodegenerative processes in dementia with Lewy bodies (DLB) and Parkinson's disease (PD). The murine Thy-1 (mThy1)-α-syn transgenic (tg) model recapitulates aspects of degenerative processes associated with α-syn accumulation in these disorders. Given that axonal and synaptic pathologies are important features of DLB and PD, we sought to investigate the extent and characteristics of these alterations in mThy1-α-syn tg mice and to determine the contribution of α-syn c-terminally cleaved at amino acid 122 (CT α-syn) to these abnormalities. We generated a novel polyclonal antibody (SYN105) against the c-terminally truncated sequence (amino acids 121 to 123) of α-syn (CT α-syn) and performed immunocytochemical and ultrastructural analyses in mThy1-α-syn tg mice. We found abundant clusters of dystrophic neurites in layers 2 to 3 of the neocortex, the stratum lacunosum, the dentate gyrus, and cornu ammonis 3 of the hippocampus, striatum, thalamus, midbrain, and pons. Dystrophic neurites displayed intense immunoreactivity detected with the SYN105 antibody. Double-labeling studies with antibodies to phosphorylated neurofilaments confirmed the axonal location of full-length and CT α-syn. α-Syn immunoreactive dystrophic neurites contained numerous electrodense laminated structures. These results show that neuritic dystrophy is a prominent pathologic feature of the mThy1-α-syn tg model and suggest that CT α-syn might play an important role in the process of axonal damage in these mice as well as in DLB and PD. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Dystrophin-deficient dogs with reduced myostatin have unequal muscle growth and greater joint contractures.

PubMed

Kornegay, Joe N; Bogan, Daniel J; Bogan, Janet R; Dow, Jennifer L; Wang, Jiahui; Fan, Zheng; Liu, Naili; Warsing, Leigh C; Grange, Robert W; Ahn, Mihye; Balog-Alvarez, Cynthia J; Cotten, Steven W; Willis, Monte S; Brinkmeyer-Langford, Candice; Zhu, Hongtu; Palandra, Joe; Morris, Carl A; Styner, Martin A; Wagner, Kathryn R

2016-01-01

Myostatin (Mstn) is a negative regulator of muscle growth whose inhibition promotes muscle growth and regeneration. Dystrophin-deficient mdx mice in which myostatin is knocked out or inhibited postnatally have a less severe phenotype with greater total mass and strength and less fibrosis and fatty replacement of muscles than mdx mice with wild-type myostatin expression. Dogs with golden retriever muscular dystrophy (GRMD) have previously been noted to have increased muscle mass and reduced fibrosis after systemic postnatal myostatin inhibition. Based partly on these results, myostatin inhibitors are in development for use in human muscular dystrophies. However, persisting concerns regarding the effects of long-term and profound myostatin inhibition will not be easily or imminently answered in clinical trials. To address these concerns, we developed a canine (GRippet) model by crossbreeding dystrophin-deficient GRMD dogs with Mstn-heterozygous (Mstn (+/-)) whippets. A total of four GRippets (dystrophic and Mstn (+/-)), three GRMD (dystrophic and Mstn wild-type) dogs, and three non-dystrophic controls from two litters were evaluated. Myostatin messenger ribonucleic acid (mRNA) and protein levels were downregulated in both GRMD and GRippet dogs. GRippets had more severe postural changes and larger (more restricted) maximal joint flexion angles, apparently due to further exaggeration of disproportionate effects on muscle size. Flexors such as the cranial sartorius were more hypertrophied on magnetic resonance imaging (MRI) in the GRippets, while extensors, including the quadriceps femoris, underwent greater atrophy. Myostatin protein levels negatively correlated with relative cranial sartorius muscle cross-sectional area on MRI, supporting a role in disproportionate muscle size. Activin receptor type IIB (ActRIIB) expression was higher in dystrophic versus control dogs, consistent with physiologic feedback between myostatin and ActRIIB. However, there was no differential expression between GRMD and GRippet dogs. Satellite cell exhaustion was not observed in GRippets up to 3 years of age. Partial myostatin loss may exaggerate selective muscle hypertrophy or atrophy/hypoplasia in GRMD dogs and worsen contractures. While muscle imbalance is not a feature of myostatin inhibition in mdx mice, findings in a larger animal model could translate to human experience with myostatin inhibitors.

Regenerative capability of skeletal muscle in chicken muscular dystrophy.

PubMed

Nonaka, I; Fujita, T; Sugita, H

1984-06-01

To examine the morphological sequence of regenerating fibers after myonecrosis in dystrophic muscles, 0.5 ml of 0.5% bupivacaine hydrochloride (BPVC) (Marcaine) solution, a local anesthetic with a cytotoxic effect on the muscle fibers, was injected directly into the dystrophic (line 413) and nondystrophic (line 412) posterior latissimus dorsi (PLD) muscles of young and adult chickens. Although the dystrophic muscles after BPVC injection showed a rapid recovery with a similar tempo to that of nondystrophic ones, they showed different morphological behavior in the early phase of regeneration, including marked variability in the size of fibers and in the intracytoplasmic enzyme activities of nicotinamide adenine dinucleotide, reduced-tetrazolium reductase (NADH-TR), acetylcholinesterase (AChE), and nonspecific esterase (NSE).

Systemic myostatin inhibition via liver-targeted gene transfer in normal and dystrophic mice.

PubMed

Morine, Kevin J; Bish, Lawrence T; Pendrak, Klara; Sleeper, Meg M; Barton, Elisabeth R; Sweeney, H Lee

2010-02-11

Myostatin inhibition is a promising therapeutic strategy to maintain muscle mass in a variety of disorders, including the muscular dystrophies, cachexia, and sarcopenia. Previously described approaches to blocking myostatin signaling include injection delivery of inhibitory propeptide domain or neutralizing antibodies. Here we describe a unique method of myostatin inhibition utilizing recombinant adeno-associated virus to overexpress a secretable dominant negative myostatin exclusively in the liver of mice. Systemic myostatin inhibition led to increased skeletal muscle mass and strength in control C57 Bl/6 mice and in the dystrophin-deficient mdx model of Duchenne muscular dystrophy. The mdx soleus, a mouse muscle more representative of human fiber type composition, demonstrated the most profound improvement in force production and a shift toward faster myosin-heavy chain isoforms. Unexpectedly, the 11-month-old mdx diaphragm was not rescued by long-term myostatin inhibition. Further, mdx mice treated for 11 months exhibited cardiac hypertrophy and impaired function in an inhibitor dose-dependent manner. Liver-targeted gene transfer of a myostatin inhibitor is a valuable tool for preclinical investigation of myostatin blockade and provides novel insights into the long-term effects and shortcomings of myostatin inhibition on striated muscle.

Imaging deep skeletal muscle structure using a high-sensitivity ultrathin side-viewing optical coherence tomography needle probe

PubMed Central

Yang, Xiaojie; Lorenser, Dirk; McLaughlin, Robert A.; Kirk, Rodney W.; Edmond, Matthew; Simpson, M. Cather; Grounds, Miranda D.; Sampson, David D.

2013-01-01

We have developed an extremely miniaturized optical coherence tomography (OCT) needle probe (outer diameter 310 µm) with high sensitivity (108 dB) to enable minimally invasive imaging of cellular structure deep within skeletal muscle. Three-dimensional volumetric images were acquired from ex vivo mouse tissue, examining both healthy and pathological dystrophic muscle. Individual myofibers were visualized as striations in the images. Degradation of cellular structure in necrotic regions was seen as a loss of these striations. Tendon and connective tissue were also visualized. The observed structures were validated against co-registered hematoxylin and eosin (H&E) histology sections. These images of internal cellular structure of skeletal muscle acquired with an OCT needle probe demonstrate the potential of this technique to visualize structure at the microscopic level deep in biological tissue in situ. PMID:24466482

Leg amputation and dystrophic epidermolysis bullosa: A case report with 15 years of follow-up.

PubMed

Thevenon, André; Preud'homme, Marguerite; Patenotre, Philippe; Catteau, Benoit; Blanchard-Dauphin, Anne; Wieczorek, Valérie; Tiffreau, Vincent

2016-10-12

Dystrophic epidermolysis bullosa is a rare disease characterized by widespread blistering of the skin and mucous membranes, which may ultimately prompt limb amputation. In this context, the outcome of fitting a prosthesis to a chronically wounded stump is not well known. Our patient's experience (with 15 years of follow-up) should contribute to better knowledge of this topic. A 37-year-old man presented with severe dystrophic epidermolysis bullosa. Recurrent skin carcinoma had led to an amputation below the knee. Despite incessant development of blisters on the stump and the need for wound dressing and padding, the patient has been able to walk freely with a prosthesis and a cane. A large number of skin sarcomas were excised over the 15-year period of prosthesis use. Two falls have resulted in limb fractures. A new sarcoma on the stump marked the end of the use of the prosthesis. Despite the constant presence of wounds on the stump, amputees with dystrophic epidermolysis bullosa can successfully be fitted with a prosthesis.

Intra-Amniotic rAAV-Mediated Microdystrophin Gene Transfer Improves Canine X-Linked Muscular Dystrophy and May Induce Immune Tolerance

PubMed Central

Hayashita-Kinoh, Hiromi; Yugeta, Naoko; Okada, Hironori; Nitahara-Kasahara, Yuko; Chiyo, Tomoko; Okada, Takashi; Takeda, Shin'ichi

2015-01-01

Duchenne muscular dystrophy (DMD) is a severe congenital disease due to mutations in the dystrophin gene. Supplementation of dystrophin using recombinant adenoassociated virus vector has promise as a treatment of DMD, although therapeutic benefit of the truncated dystrophin still remains to be elucidated. Besides, host immune responses against the vector as well as transgene products have been denoted in the clinical gene therapy studies. Here, we transduced dystrophic dogs fetuses to investigate the therapeutic effects of an AAV vector expressing microdystrophin under conditions of immune tolerance. rAAV-CMV-microdystrophin and a rAAV-CAG-luciferase were injected into the amniotic fluid surrounding fetuses. We also reinjected rAAV9-CMV-microdystrophin into the jugular vein of an infant dystrophic dog to induce systemic expression of microdystrophin. Gait and cardiac function significantly improved in the rAAV-microdystrophin-injected dystrophic dog, suggesting that an adequate treatment of rAAV-microdystrophin with immune modulation induces successful long-term transgene expression to analyze improved dystrophic phenotype. PMID:25586688

CD133+ cells derived from skeletal muscles of Duchenne muscular dystrophy patients have a compromised myogenic and muscle regenerative capability.

PubMed

Meng, Jinhong; Muntoni, Francesco; Morgan, Jennifer

2018-05-12

Cell-mediated gene therapy is a possible means to treat muscular dystrophies like Duchenne muscular dystrophy. Autologous patient stem cells can be genetically-corrected and transplanted back into the patient, without causing immunorejection problems. Regenerated muscle fibres derived from these cells will express the missing dystrophin protein, thus improving muscle function. CD133+ cells derived from normal human skeletal muscle contribute to regenerated muscle fibres and form muscle stem cells after their intra-muscular transplantation into an immunodeficient mouse model. But it is not known whether CD133+ cells derived from DMD patient muscles have compromised muscle regenerative function. To test this, we compared CD133+ cells derived from DMD and normal human muscles. DMD CD133+ cells had a reduced capacity to undergo myogenic differentiation in vitro compared with CD133+ cells derived from normal muscle. In contrast to CD133+ cells derived from normal human muscle, those derived from DMD muscle formed no satellite cells and gave rise to significantly fewer muscle fibres of donor origin, after their intra-muscular transplantation into an immunodeficient, non-dystrophic, mouse muscle. DMD CD133+ cells gave rise to more clones of smaller size and more clones that were less myogenic than did CD133+ cells derived from normal muscle. The heterogeneity of the progeny of CD133+ cells, combined with the reduced proliferation and myogenicity of DMD compared to normal CD133+ cells, may explain the reduced regenerative capacity of DMD CD133+ cells. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Glucocorticoid Steroid and Alendronate Treatment Alleviates Dystrophic Phenotype with Enhanced Functional Glycosylation of α-Dystroglycan in Mouse Model of Limb-Girdle Muscular Dystrophy with FKRPP448L Mutation.

PubMed

Wu, Bo; Shah, Sapana N; Lu, Peijuan; Richardson, Stephanie M; Bollinger, Lauren E; Blaeser, Anthony; Madden, Kyle L; Sun, Yubo; Luckie, Taylor M; Cox, Michael D; Sparks, Susan; Harper, Amy D; Lu, Qi Long

2016-06-01

Fukutin-related protein-muscular dystrophy is characterized by defects in glycosylation of α-dystroglycan with variable clinical phenotypes, most commonly as limb-girdle muscular dystrophy 2I. There is no effective therapy available. Glucocorticoid steroids have become the standard treatment for Duchenne and other muscular dystrophies with serious adverse effects, including excessive weight gain, immune suppression, and bone loss. Bisphosphonates have been used to treat Duchenne muscular dystrophy for prevention of osteoporosis. Herein, we evaluated prednisolone and alendronate for their therapeutic potential in the FKRPP448L-mutant mouse representing moderate limb-girdle muscular dystrophy 2I. Mice were treated with prednisolone, alendronate, and both in combination for up to 6 months. Prednisolone improved muscle pathology with significant reduction in muscle degeneration, but had no effect on serum creatine kinase levels and muscle strength. Alendronate treatment did not ameliorate muscle degeneration, but demonstrated a limited enhancement on muscle function test. Combined treatment of prednisolone and alendronate provided best improvement in muscle pathology with normalized fiber size distribution and significantly reduced serum creatine kinase levels, but had limited effect on muscle force generation. The use of alendronate significantly mitigated the bone loss. Prednisolone alone and in combination with alendronate enhance functionally glycosylated α-dystroglycan. These results, for the first time, demonstrate the efficacy and feasibility of this alliance treatment of the two drugs for fukutin-related protein-muscular dystrophy. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

TRAF6 regulates satellite stem cell self-renewal and function during regenerative myogenesis

PubMed Central

Hindi, Sajedah M.; Kumar, Ashok

2015-01-01

Satellite cells are a stem cell population within adult muscle and are responsible for myofiber regeneration upon injury. Satellite cell dysfunction has been shown to underlie the loss of skeletal muscle mass in many acquired and genetic muscle disorders. The transcription factor paired box-protein-7 (PAX7) is indispensable for supplementing the reservoir of satellite cells and driving regeneration in normal and diseased muscle. TNF receptor–associated factor 6 (TRAF6) is an adaptor protein and an E3 ubiquitin ligase that mediates the activation of multiple cell signaling pathways in a context-dependent manner. Here, we demonstrated that TRAF6-mediated signaling is critical for homeostasis of satellite cells and their function during regenerative myogenesis. Selective deletion of Traf6 in satellite cells of adult mice led to profound muscle regeneration defects and dramatically reduced levels of PAX7 and late myogenesis markers. TRAF6 was required for the activation of MAPKs ERK1/2 and JNK1/2, which in turn activated the transcription factor c-JUN, which binds the Pax7 promoter and augments Pax7 expression. Moreover, TRAF6/c-JUN signaling repressed the levels of the microRNAs miR-1 and miR-206, which promote differentiation, to maintain PAX7 levels in satellite cells. We also determined that satellite cell–specific deletion of Traf6 exaggerates the dystrophic phenotype in the mdx (a mouse model of Duchenne muscular dystrophy) mouse by blunting the regeneration of injured myofibers. Collectively, our study reveals an essential role for TRAF6 in satellite stem cell function. PMID:26619121

Chronic losartan administration reduces mortality and preserves cardiac but not skeletal muscle function in dystrophic mice.

PubMed

Bish, Lawrence T; Yarchoan, Mark; Sleeper, Meg M; Gazzara, Jeffrey A; Morine, Kevin J; Acosta, Pedro; Barton, Elisabeth R; Sweeney, H Lee

2011-01-01

Duchenne muscular dystrophy (DMD) is a degenerative disorder affecting skeletal and cardiac muscle for which there is no effective therapy. Angiotension receptor blockade (ARB) has excellent therapeutic potential in DMD based on recent data demonstrating attenuation of skeletal muscle disease progression during 6-9 months of therapy in the mdx mouse model of DMD. Since cardiac-related death is major cause of mortality in DMD, it is important to evaluate the effect of any novel treatment on the heart. Therefore, we evaluated the long-term impact of ARB on both the skeletal muscle and cardiac phenotype of the mdx mouse. Mdx mice received either losartan (0.6 g/L) (n = 8) or standard drinking water (n = 9) for two years, after which echocardiography was performed to assess cardiac function. Skeletal muscle weight, morphology, and function were assessed. Fibrosis was evaluated in the diaphragm and heart by Trichrome stain and by determination of tissue hydroxyproline content. By the study endpoint, 88% of treated mice were alive compared to only 44% of untreated (p = 0.05). No difference in skeletal muscle morphology, function, or fibrosis was noted in losartan-treated animals. Cardiac function was significantly preserved with losartan treatment, with a trend towards reduction in cardiac fibrosis. We saw no impact on the skeletal muscle disease progression, suggesting that other pathways that trigger fibrosis dominate over angiotensin II in skeletal muscle long term, unlike the situation in the heart. Our study suggests that ARB may be an important prophylactic treatment for DMD-associated cardiomyopathy, but will not impact skeletal muscle disease.

Diapocynin, a dimer of the NADPH oxidase inhibitor apocynin, reduces ROS production and prevents force loss in eccentrically contracting dystrophic muscle.

PubMed

Ismail, Hesham M; Scapozza, Leonardo; Ruegg, Urs T; Dorchies, Olivier M

2014-01-01

Elevation of intracellular Ca2+, excessive ROS production and increased phospholipase A2 activity contribute to the pathology in dystrophin-deficient muscle. Moreover, Ca2+, ROS and phospholipase A2, in particular iPLA2, are thought to potentiate each other in positive feedback loops. NADPH oxidases (NOX) have been considered as a major source of ROS in muscle and have been reported to be overexpressed in muscles of mdx mice. We report here on our investigations regarding the effect of diapocynin, a dimer of the commonly used NOX inhibitor apocynin, on the activity of iPLA2, Ca2+ handling and ROS generation in dystrophic myotubes. We also examined the effects of diapocynin on force production and recovery ability of isolated EDL muscles exposed to eccentric contractions in vitro, a damaging procedure to which dystrophic muscle is extremely sensitive. In dystrophic myotubes, diapocynin inhibited ROS production, abolished iPLA2 activity and reduced Ca2+ influx through stretch-activated and store-operated channels, two major pathways responsible for excessive Ca2+ entry in dystrophic muscle. Diapocynin also prevented force loss induced by eccentric contractions of mdx muscle close to the value of wild-type muscle and reduced membrane damage as seen by Procion orange dye uptake. These findings support the central role played by NOX-ROS in the pathogenic cascade leading to muscular dystrophy and suggest diapocynin as an effective NOX inhibitor that might be helpful for future therapeutic approaches.

Voluntary physical activity protects from susceptibility to skeletal muscle contraction-induced injury but worsens heart function in mdx mice.

PubMed

Hourdé, Christophe; Joanne, Pierre; Medja, Fadia; Mougenot, Nathalie; Jacquet, Adeline; Mouisel, Etienne; Pannerec, Alice; Hatem, Stéphane; Butler-Browne, Gillian; Agbulut, Onnik; Ferry, Arnaud

2013-05-01

It is well known that inactivity/activity influences skeletal muscle physiological characteristics. However, the effects of inactivity/activity on muscle weakness and increased susceptibility to muscle contraction-induced injury have not been extensively studied in mdx mice, a murine model of Duchenne muscular dystrophy with dystrophin deficiency. In the present study, we demonstrate that inactivity (ie, leg immobilization) worsened the muscle weakness and the susceptibility to contraction-induced injury in mdx mice. Inactivity also mimicked these two dystrophic features in wild-type mice. In contrast, we demonstrate that these parameters can be improved by activity (ie, voluntary wheel running) in mdx mice. Biochemical analyses indicate that the changes induced by inactivity/activity were not related to fiber-type transition but were associated with altered expression of different genes involved in fiber growth (GDF8), structure (Actg1), and calcium homeostasis (Stim1 and Jph1). However, activity reduced left ventricular function (ie, ejection and shortening fractions) in mdx, but not C57, mice. Altogether, our study suggests that muscle weakness and susceptibility to contraction-induced injury in dystrophic muscle could be attributable, at least in part, to inactivity. It also suggests that activity exerts a beneficial effect on dystrophic skeletal muscle but not on the heart. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Strontium-90 concentration factors of lake plankton, macrophytes, and substrates.

PubMed

Kalnina, Z; Polikarpov, G

1969-06-27

The ratio of concentration of strontium-90 in living and inert lake components to that in lake water (concentration factors) was determined for plankton, macrophytes, and substrates in eutrophic, mesotropric-eutrophic, and dystrophic Latgalian lakes. Concentration factors of strontium-90 in aquatic organisms and substrates are higher in a dystrophic lake than in the other types.

A Computed Tomography-Based Comparison of Abnormal Vertebrae Pedicles Between Dystrophic and Nondystrophic Scoliosis in Neurofibromatosis Type 1.

PubMed

Li, Ying; Luo, Ming; Wang, Wengang; Shen, Mingkui; Xu, Genzhong; Gao, Jianbo; Xia, Lei

2017-10-01

To explore the prevalence and distribution of abnormal vertebral pedicles in scoliosis secondary to neurofibromatosis type 1 (NF1-S) and to compare the abnormal vertebrae pedicles between dystrophic and nondystrophic scoliosis. Using computed tomography images, we carefully measured 2652 vertebral pedicles from 56 patients with NF1-S with dystrophic scoliosis and 22 patients with NF1-S with nondystrophic scoliosis. Pedicle morphology was classified as follows: type A, a cancellous channel of >4 mm; type B, a cancellous channel of 2 to 4 mm; type C, a cancellous channel of <2 mm with an entirely cortical channel of ≥2 mm; type D, a cortical channel of <2 mm; or type E, absent pedicle. Types B, C, D, and E were defined as abnormal. The total prevalence of abnormal vertebral pedicles in patients with NF1-S was as high as 67%, with type B comprising 39%, type C comprising 22%, type D comprising 4%, and type E comprising 2%. A significantly greater rate of abnormal pedicles was found in dystrophic scoliosis compared with nondystrophic scoliosis (70% vs. 59%, P < 0.0001). The upper thoracic spine (87%) is the most concentrated region of abnormal pedicles compared with the lower thoracic (73%) and lumbar spine (34%). There is a significantly high prevalence of abnormal pedicles in patients with NF1-S and an increased rate of abnormal pedicles in dystrophic scoliosis compared with nondystrophic ones. The described pedicle classification system could serve as an objective tool to guide preoperative assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

Study on contraction and relaxation of experimentally denervated and immobilized muscles: Comparison with dystrophic muscles

NASA Technical Reports Server (NTRS)

Takamori, M.; Tsujihata, M.; Mori, M.; Hazama, R.; Ide, Y.

1980-01-01

The contraction-relaxation mechanism of experimentally denervated and immobilized muscles of the rabbit is examined. Results are compared with those of human dystrophic muscles, in order to elucidate the role and extent of the neurotrophic factor, and the role played by the intrinsic activity of muscle in connection with pathogenesis and pathophysiology of this disease.

Local injections of adipose-derived mesenchymal stem cells modulate inflammation and increase angiogenesis ameliorating the dystrophic phenotype in dystrophin-deficient skeletal muscle.

PubMed

Pinheiro, Carlos Hermano da Justa; de Queiroz, Jean César Farias; Guimarães-Ferreira, Lucas; Vitzel, Kaio Fernando; Nachbar, Renato Tadeu; de Sousa, Luís Gustavo Oliveira; de Souza, Alcione Lescano; Nunes, Maria Tereza; Curi, Rui

2012-06-01

The effects of adipose-derived mesenchymal stem cells (ADMSC) transplantation on degeneration, regeneration and skeletal muscle function were investigated in dystrophin-deficient mice (24-week-old). ADMSC transplantation improved muscle strength and, resistance to fatigue. An increase in fiber cross-sectional area and in the number of fibers with centralized nuclei and augment of myogenin content were observed. In ADMSC-treated muscles a decrease in muscle content of TNF-α, IL-6 and oxidative stress measured by Amplex(®) reagent were observed. The level of TGF-β1 was lowered whereas that of VEGF, IL-10 and IL-4 were increased by ADMSC treatment. An increase in markers of macrophage M1 (CD11 and F4-80) and a decrease in T lymphocyte marker (CD3) and arginase-1 were also observed in ADMSCs-treated dystrophic muscle. No change was observed in iNOS expression. Increased phosphorylation of Akt, p70S6k and 4E-BP1 was found in dystrophic muscles treated with ADMSC. These results suggest that ADMSC transplantation modulates inflammation and improves muscle tissue regeneration, ameliorating the dystrophic phenotype in dystrophin-deficient mice.

Dystrophic Cardiomyopathy: Complex Pathobiological Processes to Generate Clinical Phenotype

PubMed Central

Tsuda, Takeshi; Fitzgerald, Kristi K.

2017-01-01

Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and X-linked dilated cardiomyopathy (XL-DCM) consist of a unique clinical entity, the dystrophinopathies, which are due to variable mutations in the dystrophin gene. Dilated cardiomyopathy (DCM) is a common complication of dystrophinopathies, but the onset, progression, and severity of heart disease differ among these subgroups. Extensive molecular genetic studies have been conducted to assess genotype-phenotype correlation in DMD, BMD, and XL-DCM to understand the underlying mechanisms of these diseases, but the results are not always conclusive, suggesting the involvement of complex multi-layers of pathological processes that generate the final clinical phenotype. Dystrophin protein is a part of dystrophin-glycoprotein complex (DGC) that is localized in skeletal muscles, myocardium, smooth muscles, and neuronal tissues. Diversity of cardiac phenotype in dystrophinopathies suggests multiple layers of pathogenetic mechanisms in forming dystrophic cardiomyopathy. In this review article, we review the complex molecular interactions involving the pathogenesis of dystrophic cardiomyopathy, including primary gene mutations and loss of structural integrity, secondary cellular responses, and certain epigenetic and other factors that modulate gene expressions. Involvement of epigenetic gene regulation appears to lead to specific cardiac phenotypes in dystrophic hearts. PMID:29367543

Compound Heterozygosity of Dominant and Recessive COL7A Alleles in a Severely Affected Patient with a Family History of Dystrophic Epidermolysis Bullosa: Clinical Findings, Genetic Testing, and Treatment Implications.

PubMed

Watson, Kendra D; Schoch, Jennifer J; Beek, Geoffrey J; Hand, Jennifer L

2017-03-01

An 8-year-old girl born to a family with more than three generations of dominant dystrophic epidermolysis bullosa (DDEB) presented with life-threatening confluent skin erosions, mitten hand deformity, and failure to thrive. Reassessment of her family history and genetic testing showed compound heterozygous COL7A mutations, one inherited from her DDEB-affected mother and one from her unaffected, healthy father. This family illustrates the risk of unexpected, severe, autosomal recessive epidermolysis bullosa (EB) in a family with milder, multigenerational autosomal dominant EB. Clinicians should recognize the clinical spectrum of dystrophic EB and recommend genetic consultation when the phenotype conflicts with family history. © 2017 Wiley Periodicals, Inc.

Mutant alpha-synuclein overexpression mediates early proinflammatory activity.

PubMed

Su, Xiaomin; Federoff, Howard J; Maguire-Zeiss, Kathleen A

2009-10-01

Microglia provide immune surveillance for the brain through both the removal of cellular debris and protection against infection by microorganisms and "foreign" molecules. Upon activation, microglia display an altered morphology and increased expression of proinflammatory molecules. Increased numbers of activated microglia have been identified in a number of neurodegenerative diseases including Parkinson's disease (PD). What remains to be determined is whether activated microglia result from ongoing cell death or are involved in disease initiation and progression. To address this question we utilized a transgenic mouse model that expresses a mutated form of a key protein involved in Parkinson's disease, alpha-synuclein. Herein, we report an increase in activated microglia and proinflammatory molecules in 1-month-old transgenic mice well before cell death occurs in this model. Frank microglial activation is resolved by 6 months of age while a subset of proinflammatory molecules remain elevated for 12 months. Both tyrosine hydroxylase mRNA expression and alpha-synuclein protein are decreased in the striatum of older animals evidence of dystrophic neuritic projections. To determine whether mutated alpha-synuclein could directly activate microglia primary microglia-enriched cell cultures were treated with exogenous mutated alpha-synuclein. The data reveal an increase in activated microglia and proinflammatory molecules due to direct interaction with mutated alpha-synuclein. Together, these data demonstrate that mutated alpha-synuclein mediates a proinflammatory response in microglia and this activity may participate in PD pathogenesis.

Mouse genome-wide association study identifies polymorphisms on chromosomes 4, 11, and 15 for age-related cardiac fibrosis.

PubMed

Li, Qiaoli; Berndt, Annerose; Sundberg, Beth A; Silva, Kathleen A; Kennedy, Victoria E; Cario, Clinton L; Richardson, Matthew A; Chase, Thomas H; Schofield, Paul N; Uitto, Jouni; Sundberg, John P

2016-06-01

Dystrophic cardiac calcinosis (DCC), also called epicardial and myocardial fibrosis and mineralization, has been detected in mice of a number of laboratory inbred strains, most commonly C3H/HeJ and DBA/2J. In previous mouse breeding studies between these DCC susceptible and the DCC-resistant strain C57BL/6J, 4 genetic loci harboring genes involved in DCC inheritance were identified and subsequently termed Dyscalc loci 1 through 4. Here, we report susceptibility to cardiac fibrosis, a sub-phenotype of DCC, at 12 and 20 months of age and close to natural death in a survey of 28 inbred mouse strains. Eight strains showed cardiac fibrosis with highest frequency and severity in the moribund mice. Using genotype and phenotype information of the 28 investigated strains, we performed genome-wide association studies (GWAS) and identified the most significant associations on chromosome (Chr) 15 at 72 million base pairs (Mb) (P < 10(-13)) and Chr 4 at 122 Mb (P < 10(-11)) and 134 Mb (P < 10(-7)). At the Chr 15 locus, Col22a1 and Kcnk9 were identified. Both have been reported to be morphologically and functionally important in the heart muscle. The strongest Chr 4 associations were located approximately 6 Mb away from the Dyscalc 2 quantitative trait locus peak within the boundaries of the Extl1 gene and in close proximity to the Trim63 and Cap1 genes. In addition, a single-nucleotide polymorphism association was found on chromosome 11. This study provides evidence for more than the previously reported 4 genetic loci determining cardiac fibrosis and DCC. The study also highlights the power of GWAS in the mouse for dissecting complex genetic traits.

Mouse genome-wide association study identifies polymorphisms on chromosomes 4, 11 and 15 for age-related cardiac fibrosis

PubMed Central

Li, Qiaoli; Berndt, Annerose; Sundberg, Beth A.; Silva, Kathleen A.; Kennedy, Victoria E.; Cario, Clinton L; Richardson, Matthew A.; Chase, Thomas H.; Schofield, Paul N.; Uitto, Jouni; Sundberg, John P.

2017-01-01

Dystrophic cardiac calcinosis (DCC), also called epicardial and myocardial fibrosis and mineralization, has been detected in mice of a number of laboratory inbred strains, most commonly C3H/HeJ and DBA/2J. In previous mouse breeding studies between these DCC susceptible and the DCC resistant strain C57BL/6J, 4 genetic loci harboring genes involved in DCC inheritance were identified and subsequently termed Dyscal loci 1 through 4. Here we report susceptibility to cardiac fibrosis, a sub-phenotype of DCC, at 12 and 20 months of age and close to natural death in a survey of 28 inbred mouse strains. Eight strains showed cardiac fibrosis with highest frequency and severity in the moribund mice. Using genotype and phenotype information of the 28 investigated strains we performed genome-wide association studies (GWAS) and identified the most significant associations on chromosome (Chr) 15 at 72 million base pairs (Mb) (P < 10−13) and Chr 4 at 122 Mb (P < 10−11) and 134 Mb (P < 10−7). At the Chr 15 locus Col22a1 and Kcnk9 were identified. Both have been reported to be morphologically and functionally important in the heart muscle. The strongest Chr 4 associations were located approximate 6 Mb away from the Dyscal 2 quantitative trait locus peak within the boundaries of the Extl1 gene and in close proximity to the Trim63 and Cap1 genes. In addition, a single nucleotide polymorphism association was found on chromosome 11. This study provides evidence for more than the previously reported 4 genetic loci determining cardiac fibrosis and DCC. The study also highlights the power of GWAS in the mouse for dissecting complex genetic traits. PMID:27126641

(−)-EPICATECHIN IMPROVES MITOCHONDRIAL RELATED PROTEIN LEVELS AND AMELIORATES OXIDATIVE STRESS IN DYSTROPHIC DELTA SARCOGLYCAN NULL MOUSE STRIATED MUSCLE

PubMed Central

Ramirez-Sanchez, Israel; De los Santos, Sergio; Gonzalez-Basurto, Silvia; Canto, Patricia; Mendoza-Lorenzo, Patricia; Palma-Flores, Carlos; Ceballos-Reyes, Guillermo; Villarreal, Francisco; Zentella-Dehesa, Alejandro; Coral-Vazquez, Ramon

2014-01-01

Muscular dystrophies (MD) are a group of heterogeneous genetic disorders characterized by progressive striated muscle wasting and degeneration. Although the genetic basis for many of these disorders has been identified, the exact mechanism for disease pathogenesis remains unclear. The presence of oxidative stress (OS) is known to contribute to the pathophysiology and severity of the MD. Mitochondrial dysfunction is observed in MD and likely represents an important determinant of increased OS. Experimental antioxidant therapies have been implemented with the aim of protecting against disease progression, but results from clinical trials have been disappointing. In this study, we explored the capacity of the cacao flavonoid (−)-epicatechin (Epi) to mitigate OS by acting as a positive regulator of mitochondrial structure/function endpoints and redox balance control systems in skeletal and cardiac muscles of dystrophic, δ-sarcoglycan (δ-SG) null mice. Wild type or δ-SG null 2.5 month old male mice were treated via oral gavage with either water (control animals) or Epi (1 mg/kg, twice/day) for 2 weeks. Results evidence a significant normalization of total protein carbonylation, recovery of reduced/oxidized glutathione (GSH/GSSG ratio) and enhanced superoxide dismutase 2, catalase and citrate synthase activities with Epi treatment. These effects were accompanied by increases in protein levels for thiolredoxin, glutathione peroxidase, superoxide dismutase 2, catalase and mitochondrial endpoints. Furthermore, we evidence decreases in heart and skeletal muscle fibrosis, accompanied with an improvement in skeletal muscle function with treatment. These results warrant the further investigation of Epi as a potential therapeutic agent to mitigate MD associated muscle degeneration. PMID:25284161

Rescue of dystrophic skeletal muscle by PGC-1α involves a fast to slow fiber type shift in the mdx mouse.

PubMed

Selsby, Joshua T; Morine, Kevin J; Pendrak, Klara; Barton, Elisabeth R; Sweeney, H Lee

2012-01-01

Increased utrophin expression is known to reduce pathology in dystrophin-deficient skeletal muscles. Transgenic over-expression of PGC-1α has been shown to increase levels of utrophin mRNA and improve the histology of mdx muscles. Other reports have shown that PGC-1α signaling can lead to increased oxidative capacity and a fast to slow fiber type shift. Given that it has been shown that slow fibers produce and maintain more utrophin than fast skeletal muscle fibers, we hypothesized that over-expression of PGC-1α in post-natal mdx mice would increase utrophin levels via a fiber type shift, resulting in more slow, oxidative fibers that are also more resistant to contraction-induced damage. To test this hypothesis, neonatal mdx mice were injected with recombinant adeno-associated virus (AAV) driving expression of PGC-1α. PGC-1α over-expression resulted in increased utrophin and type I myosin heavy chain expression as well as elevated mitochondrial protein expression. Muscles were shown to be more resistant to contraction-induced damage and more fatigue resistant. Sirt-1 was increased while p38 activation and NRF-1 were reduced in PGC-1α over-expressing muscle when compared to control. We also evaluated if the use a pharmacological PGC-1α pathway activator, resveratrol, could drive the same physiological changes. Resveratrol administration (100 mg/kg/day) resulted in improved fatigue resistance, but did not achieve significant increases in utrophin expression. These data suggest that the PGC-1α pathway is a potential target for therapeutic intervention in dystrophic skeletal muscle.

Quantitative metabolomics of photoreceptor degeneration and the effects of stem cell-derived retinal pigment epithelium transplantation

PubMed Central

Wang, Junhua; Westenskow, Peter D.; Fang, Mingliang; Friedlander, Martin

2016-01-01

Photoreceptor degeneration is characteristic of vision-threatening diseases including age-related macular degeneration. Photoreceptors are metabolically demanding cells in the retina, but specific details about their metabolic behaviours are unresolved. The quantitative metabolomics of retinal degeneration could provide valuable insights and inform future therapies. Here, we determined the metabolomic ‘fingerprint’ of healthy and dystrophic retinas in rat models using optimized metabolite extraction techniques. A number of classes of metabolites were consistently dysregulated during degeneration: vitamin A analogues, fatty acid amides, long-chain polyunsaturated fatty acids, acyl carnitines and several phospholipid species. For the first time, a distinct temporal trend of several important metabolites including DHA (4Z,7Z,10Z,13Z,16Z,19Z-docosahexaenoic acid), all-trans-retinal and its toxic end-product N-retinyl-N-retinylidene-ethanolamine were observed between healthy and dystrophic retinas. In this study, metabolomics was further used to determine the temporal effects of the therapeutic intervention of grafting stem cell-derived retinal pigment epithelium (RPE) in dystrophic retinas, which significantly prevented photoreceptor atrophy in our previous studies. The result revealed that lipid levels such as phosphatidylethanolamine in eyes were restored in those animals receiving the RPE grafts. In conclusion, this study provides insight into the metabolomics of retinal degeneration, and further understanding of the efficacy of RPE transplantation. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644974

The role of tumor necrosis factor-α-related apoptosis-inducing ligand (TRAIL) in mediating autophagy in myositis skeletal muscle: A potential non-immune mechanism of muscle damage

PubMed Central

Alger, Heather M.; Raben, Nina; Pistilli, Emidio; Francia, Dwight; Rawat, Rashmi; Getnet, Derese; Ghimbovschi, Svetlana; Chen, Yi-Wen; Lundberg, Ingrid E.; Nagaraju, Kanneboyina

2011-01-01

Objective Multinucleated cells are relatively resistant to classical apoptosis, and the factors initiating cell-death and damage in myositis are not well defined. We hypothesized that non-immune autophagic cell death may play a role in muscle fiber damage. Recent literature indicates that tumor necrosis factor-alpha-related apoptosis inducing ligand (TRAIL) may induce both NFκB (nuclear factor kappa-light chain enhancer of activated B cells) activation and autophagic cell death in other systems. Here, we have investigated its role in cell death and pathogenesis in vitro and in vivo using myositis (human and mouse) muscle tissues. Methods Gene expression profiling indicated that expression of TRAIL and several autophagy markers was specifically upregulated in myositis muscle tissue; these results were confirmed by immunohistochemistry and immunoblotting. We also analyzed TRAIL-induced cell death (apoptosis and autophagy) and NFκB activation in vitro in cultured cells. Results TRAIL was expressed predominantly in muscle fibers of myositis, but not in biopsies from normal or other dystrophic-diseased muscle. Autophagy markers were upregulated in human and mouse models of myositis. TRAIL expression was restricted to regenerating/atrophic areas of muscle fascicles, blood vessels, and infiltrating lymphocytes. TRAIL induced NFκB activation and IκB degradation in cultured cells that are resistant to TRAIL-induced apoptosis but undergo autophagic cell death. Conclusion Our data demonstrate that TRAIL is expressed in myositis muscle and may mediate both activation of NFκB and autophagic cell death in myositis. Thus, this non-immune pathway may be an attractive target for therapeutic intervention in myositis. PMID:21769834

Fetal myosin immunoreactivity in human dystrophic muscle.

PubMed

Schiaffino, S; Gorza, L; Dones, I; Cornelio, F; Sartore, S

1986-01-01

We report immunofluorescence observations on normal and dystrophic human muscle using an antibody (anti-bF) raised against bovine fetal myosin and specific for fetal myosin heavy chains. In rat skeletal muscle, anti-bF was previously found to react selectively with myosin isoforms expressed during fetal and early postnatal development and in regenerating muscles. Anti-bF stained most fibers in human fetal and neonatal muscle, whereas only nuclear chain fibers of muscle spindles were labeled in normal adult muscle. In muscle biopsies from patients with Duchenne's muscular dystrophy, numerous extrafusal fibers were stained: some were small regenerating fibers, others were larger fibers presumably resulting from previous regenerative events. Fetal myosin immunoreactivity in Duchenne's dystrophy appears to reflect the reexpression of fetal-specific myosin isoforms and provides a new valuable tool for identifying regenerating fibers and following their destiny in dystrophic muscle.

Preservation of visual cortical function following retinal pigment epithelium transplantation in the RCS rat using optical imaging techniques.

PubMed

Gias, Carlos; Jones, Myles; Keegan, David; Adamson, Peter; Greenwood, John; Lund, Ray; Martindale, John; Johnston, David; Berwick, Jason; Mayhew, John; Coffey, Peter

2007-04-01

The aim of this study was to determine the extent of cortical functional preservation following retinal pigment epithelium (RPE) transplantation in the Royal College of Surgeons (RCS) rat using single-wavelength optical imaging and spectroscopy. The cortical responses to visual stimulation in transplanted rats at 6 months post-transplantation were compared with those from age-matched untreated dystrophic and non-dystrophic rats. Our results show that cortical responses were evoked in non-dystrophic rats to both luminance changes and pattern stimulation, whereas no response was found in untreated dystrophic animals to any of the visual stimuli tested. In contrast, a cortical response was elicited in most of the transplanted rats to luminance changes and in many of those a response was also evoked to pattern stimulation. Although the transplanted rats did not respond to high spatial frequency information we found evidence of preservation in the cortical processing of luminance changes and low spatial frequency stimulation. Anatomical sections of transplanted rat retinas confirmed the capacity of RPE transplantation to rescue photoreceptors. Good correlation was found between photoreceptor survival and the extent of cortical function preservation determined with optical imaging techniques. This study determined the efficacy of RPE transplantation to preserve visual cortical processing and established optical imaging as a powerful technique for its assessment.

Reducing CTGF/CCN2 slows down mdx muscle dystrophy and improves cell therapy.

PubMed

Morales, Maria Gabriela; Gutierrez, Jaime; Cabello-Verrugio, Claudio; Cabrera, Daniel; Lipson, Kenneth E; Goldschmeding, Roel; Brandan, Enrique

2013-12-15

In Duchenne muscular dystrophy (DMD) and the mdx mouse model, the absence of the cytoskeletal protein dystrophin causes defective anchoring of myofibres to the basal lamina. The resultant myofibre degeneration and necrosis lead to a progressive loss of muscle mass, increased fibrosis and ultimately fatal weakness. Connective tissue growth factor (CTGF/CCN-2) is critically involved in several chronic fibro-degenerative diseases. In DMD, the role of CTGF might extend well beyond replacement fibrosis secondary to loss of muscle fibres, since its overexpression in skeletal muscle could by itself induce a dystrophic phenotype. Using two independent approaches, we here show that mdx mice with reduced CTGF availability do indeed have less severe muscular dystrophy. Mdx mice with hemizygous CTGF deletion (mdx-Ctgf+/-), and mdx mice treated with a neutralizing anti-CTGF monoclonal antibody (FG-3019), performed better in an exercise endurance test, had better muscle strength in isolated muscles and reduced skeletal muscle impairment, apoptotic damage and fibrosis. Transforming growth factor type-β (TGF-β), pERK1/2 and p38 signalling remained unaffected during CTGF suppression. Moreover, both mdx-Ctgf+/- and FG-3019 treated mdx mice had improved grafting upon intramuscular injection of dystrophin-positive satellite cells. These findings reveal the potential of targeting CTGF to reduce disease progression and to improve cell therapy in DMD.

Restorative and periodontal challenges in adults with dystrophic epidermolysis bullosa.

PubMed

Puliyel, Divya; Chiu, Ching Hsiu Ketty; Habibian, Mina

2014-05-01

Oral manifestations of dystrophic epidermolysis bullosa (DEB) include blistering of the oral mucosa, scarring, limited mouth opening, decreased mobility of the tongue, restrictions in oral functions and a high incidence of caries. Adult oral health management is challenging and requires unique strategies, which have not been well described in the published literature. We present a case of DEB focusing on the obstacles encountered during restorative and periodontal care and recommendations for appropriate treatment.

Longitudinal fibre splitting in muscular dystrophy: a serial cinematographic study

PubMed Central

Isaacs, Edward R.; Bradley, Walter G.; Henderson, Gerald

1973-01-01

A technique of block surface-staining and serial cinematography was modified to review serial sections of normal and dystrophic muscle from the Bar Harbor 129 Re strain of mice as a preliminary study of fibre splitting in dystrophic muscle. Using this technique, muscle fibres were reconstructed for up to 1·5 mm of their length without difficulty. Split fibres were identified only when the actual separation of fibres was observed. Splitting was seen to be a significant cause of the variations in fibre diameter and was at times responsible for the formation of groups of small atrophic fibres which resembled those seen in denervation atrophy. Complex multiple splitting and recombination of daughter and parent fibres was also observed and reconstructed to scale. These results may have considerable significance for the interpretation of physiological data on both human and murine dystrophic muscle. Images PMID:4753877

A novel PNPLA2 mutation causes neutral lipid storage disease with myopathy (NLSDM) presenting muscular dystrophic features with lipid storage and rimmed vacuoles.

PubMed

Chen, J; Hong, D; Wang, Z; Yuan, Y

2010-01-01

Neutral lipid storage disease with myopathy (NLSDM) is a type of lipid storage myopathy arising due to a mutation in the PNPLA2 gene encoding an adipose triglyceride lipase responsible for the degradation of intracellular triglycerides. Herein, we report the cases of two siblings manifesting slowly progressive proximal and distal limb weakness in adulthood. One of the patients had dilated cardiomyopathy, hearing loss and short stature. Muscle specimens of the 2 patients revealed muscular dystrophic features with massive lipid droplets and numerous rimmed vacuoles in the fibers. A novel homozygous mutation IVS2+1G > A in the PNPLA2 gene was identified in the 2 cases, but not in the healthy familial individuals. The presence of massive lipid droplets with muscular dystrophic changes and rimmed vacuoles in muscle fibers might be one of the characteristic pathological changes of NLSDM.

Treatment of dystrophic calcification on a silicone intraocular lens with pars plana vitrectomy

PubMed Central

Mehta, Nitish; Goldberg, Roger A; Shah, Chirag P

2014-01-01

Purpose Dense, vision-obscuring calcification on the posterior aspect of silicone intraocular lenses (IOLs) is often not amenable to neodymium:yttrium-aluminum-garnet capsulotomy, and, in prior reports, has required IOL exchange. We report the successful removal of dense calcium deposition on the posterior surface of a three-piece silicone lens using pars plana vitrectomy (PPV). Materials and methods A 23-gauge PPV was performed using the Stellaris® vitrectomy system. A light pipe was used to retroilluminate the IOL, and a dense fibrous tissue setting with a low cut-rate and high aspiration rate was able to clear the visual axis of the dystrophic calcification without damaging the IOL optic. Results Visual acuity improved from 20/100 to 20/25. Conclusion Small-gauge PPV may be utilized to remove dense dystrophic calcium deposits on the lens surface in lieu of IOL exchange. PMID:25045246

Distal mdx muscle groups exhibiting up-regulation of utrophin and rescue of dystrophin-associated glycoproteins exemplify a protected phenotype in muscular dystrophy

NASA Astrophysics Data System (ADS)

Dowling, Paul; Culligan, Kevin; Ohlendieck, Kay

2002-02-01

Unique unaffected skeletal muscle fibres, unlike necrotic torso and limb muscles, may pave the way for a more detailed understanding of the molecular pathogenesis of inherited neuromuscular disorders and help to develop new treatment strategies for muscular dystrophies. The sparing of extraocular muscle in Duchenne muscular dystrophy is mostly attributed to the special protective properties of extremely fast-twitching small-diameter fibres, but here we show that distal muscles also represent a particular phenotype that is more resistant to necrosis. Immunoblot analysis of membranes isolated from the well established dystrophic animal model mdx shows that, in contrast to dystrophic limb muscles, the toe musculature exhibits an up-regulation of the autosomal dystrophin homologue utrophin and a concomitant rescue of dystrophin-associated glycoproteins. Thus distal mdx muscle groups provide a cellular system that naturally avoids myofibre degeneration which might be useful in the search for naturally occurring compensatory mechanisms in inherited skeletal muscle diseases.

Morphological and functional analyses of skeletal muscles from an immunodeficient animal model of limb-girdle muscular dystrophy type 2E.

PubMed

Giovannelli, Gaia; Giacomazzi, Giorgia; Grosemans, Hanne; Sampaolesi, Maurilio

2018-02-24

Limb-girdle muscular dystrophy type 2E (LGMD2E) is caused by mutations in the β-sarcoglycan gene, which is expressed in skeletal, cardiac, and smooth muscles. β-Sarcoglycan-deficient (Sgcb-null) mice develop severe muscular dystrophy and cardiomyopathy with focal areas of necrosis. In this study we performed morphological (histological and cellular characterization) and functional (isometric tetanic force and fatigue) analyses in dystrophic mice. Comparison studies were carried out in 1-month-old (clinical onset of the disease) and 7-month-old control mice (C57Bl/6J, Rag2/γc-null) and immunocompetent and immunodeficient dystrophic mice (Sgcb-null and Sgcb/Rag2/γc-null, respectively). We found that the lack of an immunological system resulted in an increase of calcification in striated muscles without impairing extensor digitorum longus muscle performance. Sgcb/Rag2/γc-null muscles showed a significant reduction of alkaline phosphate-positive mesoangioblasts. The immunological system counteracts skeletal muscle degeneration in the murine model of LGMD2E. Muscle Nerve, 2018. © 2018 The Authors. Muscle & Nerve Published by Wiley Periodicals, Inc.

Moderation of phenotypic severity in dystrophic and junctional forms of epidermolysis bullosa through in-frame skipping of exons containing non-sense or frameshift mutations.

PubMed

McGrath, J A; Ashton, G H; Mellerio, J E; Salas-Alanis, J C; Swensson, O; McMillan, J R; Eady, R A

1999-09-01

Non-sense mutations on both alleles of either the type VII collagen gene (COL7A1) or the genes encoding laminin 5 (LAMA3, LAMB3, or LAMC2) usually result in clinically severe forms of recessive dystrophic or junctional epidermolysis bullosa, respectively. In this study we assessed two unrelated families whose mutations in genomic DNA predicted severe recessive dystrophic epidermolysis bullosa or junctional epidermolysis bullosa phenotypes but in whom the manifestations were milder than expected. The recessive dystrophic epidermolysis bullosa patients had a homozygous single base-pair frameshift mutation in exon 19 of COL7A1 (2470insG). Clinically, there was generalized blistering but only mild scarring. Skin biopsy revealed positive type VII collagen immunoreactivity and recognizable anchoring fibrils. The junctional epidermolysis bullosa patients were compound heterozygotes for a frameshift/non-sense combination of mutations in exons 3 and 17 of LAMB3 (29insC/Q834X). These patients did not have the lethal form of junctional epidermolysis bullosa but, as adults, displayed the milder generalized atrophic benign epidermolysis bullosa variant. There was undetectable laminin 5 staining at the dermal-epidermal junction using an antibody to the beta3 chain, but faintly positive alpha3 and gamma2 chain labeling, and there was variable hypoplasia of hemidesmosomes. To explain the milder recessive dystrophic epidermolysis bullosa and junctional epidermolysis bullosa phenotypes in these families, reverse transcription-polymerase chain reaction, using RNA extracted from frozen skin, was able to provide evidence for some rescue of mutant mRNA transcripts with restoration of the open- reading frame. In the recessive dystrophic epidermolysis bullosa patients, transcripts containing in-frame skipping of exon 19 of COL7A1 in the cDNA were detected, and in the junctional epidermolysis bullosa patients transcripts with in-frame skipping of exon 17 of LAMB3 were identified. The truncated proteins encoded by these transcripts are expected to lack certain critical domains involved in cell-matrix attachment, but may still be able to contribute to adhesion thereby moderating the severity of the skin blistering. This study shows the limitations in predicting phenotype in epidermolysis bullosa solely based on mutation analysis of genomic DNA and emphasizes the importance of immunohistochemistry, electron microscopy, and mRNA assessment as parallel investigations.

Genetic Evaluation for the Scoliosis Gene(s) in Patients with Neurofibromatosis 1 and Scoliosis

DTIC Science & Technology

2014-08-01

Genetic Evaluation for the Scoliosis Gene(s) in Patients with Neurofibromatosis 1 and Scoliosis PRINCIPAL INVESTIGATOR: David W. Polly, Jr... Neurofibromatosis 1 and Scoliosis 5b. GRANT NUMBER W81XWH-10-1-0469 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) David. W. Polly Jr., MD 5d. PROJECT...dystrophic scoliosis is one of most common skeletal manifestations of Neurofibromatosis type 1. Dystrophic scoliosis has a more progressive and

Dystrophic mineralization of the arterial fibrovascular tissue associated with a vitamin D hypervitaminosis in an 8-year-old female Alpaca (Vicugna pacos).

PubMed

Tavella, Alexander; Stefani, Annalisa; Zanardello, Claudia; Bettini, Astrid; Gauly, Matthias; Zanolari, Patrik

2016-01-01

Prophylactic Vitamin D supplementation is a common practice in Alpaca breeding in many regions around the world. An overdosage can lead to dystrophic mineralization of soft tissues. In this paper we illustrate a suspected case of hypervitaminosis D in an 8-year-old female Alpaca. In June 2015, the carcass of an 8-year-old female Alpaca ( Vicugna pacos ) was submitted to the diagnostic laboratory of the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe) for necropsy. The animal had undergone a spontaneous abortion with uterine prolapse and delivery of the placenta, and had died shortly thereafter. Death occurred due to internal haemorrhage related to dystrophic mineralization of the left renal artery with subsequent rupture and damage of the renal hilum. During the necropsy, histopathological and serum biochemical analyses were performed. After laboratory analyses and the history of mineral and vitamin supplementation reported by the breeder, a hypervitaminosis D was suspected to be the most probable cause of the dystrophic mineralization observed in the left renal artery. Most of the information regarding Llamas and Alpacas comes from the South American and Australian regions. It is therefore important to provide scientific information about these animals in other regions of the world in order to have a better and wider understanding of the nutritional and environmental conditions necessary for optimal breeding.

Dystrophic Serotonin Axons in Postmortem Brains from Young Autism Patients

PubMed Central

Azmitia, Efrain C.; Singh, Jorawer S.; Hou, Xiao P.; Wiegel, Jerzy

2014-01-01

Autism causes neuropathological changes in varied anatomical loci. A coherent neural mechanism to explain the spectrum of autistic symptomatology has not been proposed because most anatomical researchers focus on point-to-point functional neural systems (e.g. auditory, social networks) rather than considering global chemical neural systems. Serotonergic neurons have a global innervation pattern. Their cell bodies are found in the midbrain but they project their axons throughout the neural axis beginning in the fetal brain. This global system is implicated in autism by animal models and by biochemical, imaging, pharmacological, and genetics studies. However, no anatomical studies of the 5-HT innervation of autistic donors have been reported. Our review presents immunocytochemical evidence of an increase in 5-HT axons in post-mortem brain tissue from autism donors aged 2.8 to 29 years relative to controls. This increase is observed in the principle ascending fiber bundles of the medial and lateral forebrain bundles, and in the innervation density of the amygdala and the piriform, superior temporal, and parahippocampal cortices. In autistic donors eight years of age and up, several types of dystrophic 5-HT axons were seen in the termination fields. One class of these dystrophic axons, the thick heavily stained axons, was not seen in the brains of patients with neurodegenerative diseases. These findings provide morphological evidence for the involvement of serotonin neurons in the early etiology of autism, and suggest a diet therapy may be effective to blunt serotonin’s trophic actions during early brain development in children. PMID:21901837

Dystrophic serotonin axons in postmortem brains from young autism patients.

PubMed

Azmitia, Efrain C; Singh, Jorawer S; Hou, Xiao P; Wegiel, Jerzy

2011-10-01

Autism causes neuropathological changes in varied anatomical loci. A coherent neural mechanism to explain the spectrum of autistic symptomatology has not been proposed because most anatomical researchers focus on point-to-point functional neural systems (e.g., auditory and social networks) rather than considering global chemical neural systems. Serotonergic neurons have a global innervation pattern. Disorders Research Program, AS073234, Program Project (JW). Their cell bodies are found in the midbrain but they project their axons throughout the neural axis beginning in the fetal brain. This global system is implicated in autism by animal models and by biochemical, imaging, pharmacological, and genetics studies. However, no anatomical studies of the 5-HT innervation of autistic donors have been reported. Our review presents immunocytochemical evidence of an increase in 5-HT axons in postmortem brain tissue from autism donors aged 2.8-29 years relative to controls. This increase is observed in the principle ascending fiber bundles of the medial and lateral forebrain bundles, and in the innervation density of the amygdala and the piriform, superior temporal, and parahippocampal cortices. In autistic donors 8 years of age and up, several types of dystrophic 5-HT axons were seen in the termination fields. One class of these dystrophic axons, the thick heavily stained axons, was not seen in the brains of patients with neurodegenerative diseases. These findings provide morphological evidence for the involvement of serotonin neurons in the early etiology of autism, and suggest new therapies may be effective to blunt serotonin's trophic actions during early brain development in children. Copyright © 2011 Wiley-Liss, Inc.

A mouse anti-myostatin antibody increases muscle mass and improves muscle strength and contractility in the mdx mouse model of Duchenne muscular dystrophy and its humanized equivalent, domagrozumab (PF-06252616), increases muscle volume in cynomolgus monkeys.

PubMed

St Andre, Michael; Johnson, Mark; Bansal, Prashant N; Wellen, Jeremy; Robertson, Andrew; Opsahl, Alan; Burch, Peter M; Bialek, Peter; Morris, Carl; Owens, Jane

2017-11-09

The treatments currently approved for Duchenne muscular dystrophy (DMD), a progressive skeletal muscle wasting disease, address the needs of only a small proportion of patients resulting in an urgent need for therapies that benefit all patients regardless of the underlying mutation. Myostatin is a member of the transforming growth factor-β (TGF-β) family of ligands and is a negative regulator of skeletal muscle mass. Loss of myostatin has been shown to increase muscle mass and improve muscle function in both normal and dystrophic mice. Therefore, myostatin blockade via a specific antibody could ameliorate the muscle weakness in DMD patients by increasing skeletal muscle mass and function, thereby reducing patients' functional decline. A murine anti-myostatin antibody, mRK35, and its humanized analog, domagrozumab, were developed and their ability to inhibit several TGB-β ligands was measured using a cell-based Smad-activity reporter system. Normal and mdx mice were treated with mRK35 to examine the antibody's effect on body weight, lean mass, muscle weights, grip strength, ex vivo force production, and fiber size. The humanized analog (domagrozumab) was tested in non-human primates (NHPs) for changes in skeletal muscle mass and volume as well as target engagement via modulation of circulating myostatin. Both the murine and human antibodies are specific and potent inhibitors of myostatin and GDF11. mRK35 is able to increase body weight, lean mass, and muscle weights in normal mice. In mdx mice, mRK35 significantly increased body weight, muscle weights, grip strength, and ex vivo force production in the extensor digitorum longus (EDL) muscle. Further, tibialis anterior (TA) fiber size was significantly increased. NHPs treated with domagrozumab demonstrated a dose-dependent increase in lean mass and muscle volume and exhibited increased circulating levels of myostatin demonstrating target engagement. We demonstrated that the potent anti-myostatin antibody mRK35 and its clinical analog, domagrozumab, were able to induce muscle anabolic activity in both rodents, including the mdx mouse model of DMD, and non-human primates. A Phase 2, potentially registrational, clinical study with domagrozumab in DMD patients is currently underway.

Dual AAV therapy ameliorates exercise-induced muscle injury and functional ischemia in murine models of Duchenne muscular dystrophy.

PubMed

Zhang, Yadong; Yue, Yongping; Li, Liang; Hakim, Chady H; Zhang, Keqing; Thomas, Gail D; Duan, Dongsheng

2013-09-15

Neuronal nitric oxide synthase (nNOS) membrane delocalization contributes to the pathogenesis of Duchenne muscular dystrophy (DMD) by promoting functional muscle ischemia and exacerbating muscle injury during exercise. We have previously shown that supra-physiological expression of nNOS-binding mini-dystrophin restores normal blood flow regulation and prevents functional ischemia in transgenic mdx mice, a DMD model. A critical next issue is whether systemic dual adeno-associated virus (AAV) gene therapy can restore nNOS-binding mini-dystrophin expression and mitigate muscle activity-related functional ischemia and injury. Here, we performed systemic gene transfer in mdx and mdx4cv mice using a pair of dual AAV vectors that expressed a 6 kb nNOS-binding mini-dystrophin gene. Vectors were packaged in tyrosine mutant AAV-9 and co-injected (5 × 10(12) viral genome particles/vector/mouse) via the tail vein to 1-month-old dystrophin-null mice. Four months later, we observed 30-50% mini-dystrophin positive myofibers in limb muscles. Treatment ameliorated histopathology, increased muscle force and protected against eccentric contraction-induced injury. Importantly, dual AAV therapy successfully prevented chronic exercise-induced muscle force drop. Doppler hemodynamic assay further showed that therapy attenuated adrenergic vasoconstriction in contracting muscle. Our results suggest that partial transduction can still ameliorate nNOS delocalization-associated functional deficiency. Further evaluation of nNOS binding mini-dystrophin dual AAV vectors is warranted in dystrophic dogs and eventually in human patients.

Adaptive strength gains in dystrophic muscle exposed to repeated bouts of eccentric contraction

PubMed Central

Call, Jarrod A.; Eckhoff, Michael D.; Baltgalvis, Kristen A.; Warren, Gordon L.

2011-01-01

The objective of this study was to determine the functional recovery and adaptation of dystrophic muscle to multiple bouts of contraction-induced injury. Because lengthening (i.e., eccentric) contractions are extremely injurious for dystrophic muscle, it was considered that repeated bouts of such contractions would exacerbate the disease phenotype in mdx mice. Anterior crural muscles (tibialis anterior and extensor digitorum longus) and posterior crural muscles (gastrocnemius, soleus, and plantaris) from mdx mice performed one or five repeated bouts of 100 electrically stimulated eccentric contractions in vivo, and each bout was separated by 10–18 days. Functional recovery from one bout was achieved 7 days after injury, which was in contrast to a group of wild-type mice, which still showed a 25% decrement in electrically stimulated isometric torque at that time point. Across bouts there was no difference in the immediate loss of strength after repeated bouts of eccentric contractions for mdx mice (−70%, P = 0.68). However, after recovery from each bout, dystrophic muscle had greater torque-generating capacity such that isometric torque was increased ∼38% for both anterior and posterior crural muscles at bout 5 compared with bout 1 (P < 0.001). Moreover, isolated extensor digitorum longus muscles excised from in vivo-tested hindlimbs 14–18 days after bout 5 had greater specific force than contralateral control muscles (12.2 vs. 10.4 N/cm2, P = 0.005) and a 20% greater maximal relaxation rate (P = 0.049). Additional adaptations due to the multiple bouts of eccentric contractions included rapid recovery and/or sparing of contractile proteins, enhanced parvalbumin expression, and a decrease in fiber size variability. In conclusion, eccentric contractions are injurious to dystrophic skeletal muscle; however, the muscle recovers function rapidly and adapts to repeated bouts of eccentric contractions by improving strength. PMID:21960659

Does intraoperative navigation improve the accuracy of pedicle screw placement in the apical region of dystrophic scoliosis secondary to neurofibromatosis type I: comparison between O-arm navigation and free-hand technique.

PubMed

Jin, Mengran; Liu, Zhen; Liu, Xingyong; Yan, Huang; Han, Xiao; Qiu, Yong; Zhu, Zezhang

2016-06-01

To assess the accuracy of O-arm-navigation-based pedicle screw insertion in dystrophic scoliosis secondary to NF-1 and compare it with free-hand pedicle screw insertion technique. 32 patients with dystrophic NF-1-associated scoliosis were divided into two groups. A total of 92 pedicle screws were implanted in apical region (two vertebrae above and below the apex each) in 13 patients using O-arm-based navigation (O-arm group), and 121 screws were implanted in 19 patients using free-hand technique (free-hand group). The postoperative CT images were reviewed and analyzed for pedicle violation. The screw penetration was divided into four grades: grade 0 (ideal placement), grade 1 (penetration <2 mm), grade 2 (penetration between 2 and 4 mm), and grade 3 (penetration >4 mm). The accuracy rate of pedicle screw placement (grade 0, 1) was significantly higher in the O-arm group (79 %, 73/92) compared to 67 % (81/121) of the free-hand group (P = 0.045). Meanwhile, a significantly lower prevalence of grade 2-3 perforation was observed in the O-arm group (21 vs. 33 %, P < 0.05), and the incidence of medial perforation was significantly minimized by using O-arm navigation compared to free-hand technique (2 vs. 15 %, P < 0.01). Moreover, the implant density in apical region was significantly elevated by using O-arm navigation (58 vs. 42 %, P < 0.001). We reported 79 % accuracy of O-arm-based pedicle screw placement in dystrophic NF-1-associated scoliosis. O-arm navigation system does facilitate pedicle screw insertion in dystrophic NF-1-associated scoliosis, demonstrating superiorities in the safety and accuracy of pedicle screw placement in comparison with free-hand technique.

Abnormal splicing switch of DMD's penultimate exon compromises muscle fibre maintenance in myotonic dystrophy.

PubMed

Rau, Frédérique; Lainé, Jeanne; Ramanoudjame, Laetitita; Ferry, Arnaud; Arandel, Ludovic; Delalande, Olivier; Jollet, Arnaud; Dingli, Florent; Lee, Kuang-Yung; Peccate, Cécile; Lorain, Stéphanie; Kabashi, Edor; Athanasopoulos, Takis; Koo, Taeyoung; Loew, Damarys; Swanson, Maurice S; Le Rumeur, Elisabeth; Dickson, George; Allamand, Valérie; Marie, Joëlle; Furling, Denis

2015-05-28

Myotonic Dystrophy type 1 (DM1) is a dominant neuromuscular disease caused by nuclear-retained RNAs containing expanded CUG repeats. These toxic RNAs alter the activities of RNA splicing factors resulting in alternative splicing misregulation and muscular dysfunction. Here we show that the abnormal splicing of DMD exon 78 found in dystrophic muscles of DM1 patients is due to the functional loss of MBNL1 and leads to the re-expression of an embryonic dystrophin in place of the adult isoform. Forced expression of embryonic dystrophin in zebrafish using an exon-skipping approach severely impairs the mobility and muscle architecture. Moreover, reproducing Dmd exon 78 missplicing switch in mice induces muscle fibre remodelling and ultrastructural abnormalities including ringed fibres, sarcoplasmic masses or Z-band disorganization, which are characteristic features of dystrophic DM1 skeletal muscles. Thus, we propose that splicing misregulation of DMD exon 78 compromises muscle fibre maintenance and contributes to the progressive dystrophic process in DM1.

Abnormal splicing switch of DMD's penultimate exon compromises muscle fibre maintenance in myotonic dystrophy

PubMed Central

Rau, Frédérique; Lainé, Jeanne; Ramanoudjame, Laetitita; Ferry, Arnaud; Arandel, Ludovic; Delalande, Olivier; Jollet, Arnaud; Dingli, Florent; Lee, Kuang-Yung; Peccate, Cécile; Lorain, Stéphanie; Kabashi, Edor; Athanasopoulos, Takis; Koo, Taeyoung; Loew, Damarys; Swanson, Maurice S.; Le Rumeur, Elisabeth; Dickson, George; Allamand, Valérie; Marie, Joëlle; Furling, Denis

2015-01-01

Myotonic Dystrophy type 1 (DM1) is a dominant neuromuscular disease caused by nuclear-retained RNAs containing expanded CUG repeats. These toxic RNAs alter the activities of RNA splicing factors resulting in alternative splicing misregulation and muscular dysfunction. Here we show that the abnormal splicing of DMD exon 78 found in dystrophic muscles of DM1 patients is due to the functional loss of MBNL1 and leads to the re-expression of an embryonic dystrophin in place of the adult isoform. Forced expression of embryonic dystrophin in zebrafish using an exon-skipping approach severely impairs the mobility and muscle architecture. Moreover, reproducing Dmd exon 78 missplicing switch in mice induces muscle fibre remodelling and ultrastructural abnormalities including ringed fibres, sarcoplasmic masses or Z-band disorganization, which are characteristic features of dystrophic DM1 skeletal muscles. Thus, we propose that splicing misregulation of DMD exon 78 compromises muscle fibre maintenance and contributes to the progressive dystrophic process in DM1. PMID:26018658

DYSTROPHIC CALCIFICATION OF MAXILLARY SINUS IN PEDIATRIC PATIENTS WITH LIVER TRANSPLANTATION AND PIGMENTATION OF DENTAL ORGAN

PubMed Central

de Macedo, Adriana Furtado; Costa, Claudio; Mattar, Regina Helena Guedes da Motta; de Azevedo, Ramiro Anthero

2017-01-01

ABSTRACT Objective: To report a case of severe dystrophic calcification in maxillary sinus of a child with liver transplantation and dental organs pigmented by hyperbilirubinemia. Case description: female patient, 12 years old, with liver transplantation performed at the age of 7 due to extrahepatic biliary atresia (EHBA). The patient was receiving the immunosuppressant tacrolimus (2 mg daily). Intraoral clinical exam showed tooth green pigmentation by bilirubin. Cone-beam volumetric computed tomography (CT) was performed to verify radiographic density of pigmented dental elements. Hounsfield scale measurement did not show changes in radiographic density of dental structures. However, CT scan showed intense dystrophic calcification in the maxillary sinus region. Comments: CT scan indicated relevant radiographic findings, with radiopacity of the maxillary sinus due to fungal or non-fungal sinusitis. This case report highlights the presence of radiographic image associated with acute infectious processes that could compromise the systemic state of immunosuppressed patients. PMID:29166493

Homeostatic Plasticity Mediated by Rod-Cone Gap Junction Coupling in Retinal Degenerative Dystrophic RCS Rats

PubMed Central

Hou, Baoke; Fu, Yan; Weng, Chuanhuang; Liu, Weiping; Zhao, Congjian; Yin, Zheng Qin

2017-01-01

Rod-cone gap junctions open at night to allow rod signals to pass to cones and activate the cone-bipolar pathway. This enhances the ability to detect large, dim objects at night. This electrical synaptic switch is governed by the circadian clock and represents a novel form of homeostatic plasticity that regulates retinal excitability according to network activity. We used tracer labeling and ERG recording in the retinae of control and retinal degenerative dystrophic RCS rats. We found that in the control animals, rod-cone gap junction coupling was regulated by the circadian clock via the modulation of the phosphorylation of the melatonin synthetic enzyme arylalkylamine N-acetyltransferase (AANAT). However, in dystrophic RCS rats, AANAT was constitutively phosphorylated, causing rod-cone gap junctions to remain open. A further b/a-wave ratio analysis revealed that dystrophic RCS rats had stronger synaptic strength between photoreceptors and bipolar cells, possibly because rod-cone gap junctions remained open. This was despite the fact that a decrease was observed in the amplitude of both a- and b-waves as a result of the progressive loss of rods during early degenerative stages. These results suggest that electric synaptic strength is increased during the day to allow cone signals to pass to the remaining rods and to be propagated to rod bipolar cells, thereby partially compensating for the weak visual input caused by the loss of rods. PMID:28473754

[Pathomechanism and therapeutic strategy of Fukuyama congenital muscular dystrophy and related disorders].

PubMed

Toda, Tatsushi

2009-11-01

Hypoglycosylation and reduced laminin-binding activity of alpha-dystroglycan are common characteristics of dystroglycanopathy, which is a group of congenital and limb-girdle muscular dystrophies. We previously identified the genes for Fukuyama congenital muscular dystrophy (FCMD) and muscle-eye-brain disease (MEB). FCMD, caused by a mutation in the fukutin gene, is a severe form of dystroglycanopathy. Knock-in mice carrying the founder retrotransposal insertion exhibited hypoglycosylated alpha-dystroglycan; however, no signs of muscular dystrophy were observed. More sensitive methods detected minor levels of intact alpha-dystroglycan, and solid-phase assays determined laminin binding levels to be approximately 50% of normal. In contrast, intact alpha-dystroglycan is undetectable in the dystrophic Large mouse, and laminin-binding activity is markedly reduced. These data indicate that a small amount of intact alpha-dystroglycan is sufficient to maintain muscle cell integrity in knock-in mice, suggesting that the treatment of dystroglycanopathies might not require the full recovery of glycosylation. Transfer of fukutin into knock-in mice restored glycosylation of alpha-dystroglycan. Transfer of LARGE produced laminin-binding forms of alpha-dystroglycan in both knock-in mice and the POMGnT1 mutant mouse. These data suggest that even partial restoration of alpha-dystroglycan glycosylation and laminin-binding activity by replacing or augmenting glycosylation-related genes might effectively deter dystroglycanopathy progression and thus provide therapeutic benefits.

Increased Expression of Laminin Subunit Alpha 1 Chain by dCas9-VP160.

PubMed

Perrin, Arnaud; Rousseau, Joël; Tremblay, Jacques P

2017-03-17

Laminin-111 protein complex links the extracellular matrix to integrin α7β1 in sarcolemma, thus replacing in dystrophic muscles links normally insured by the dystrophin complex. Laminin-111 injection in mdx mouse stabilized sarcolemma, restored serum creatine kinase to wild-type levels, and protected muscles from exercised-induced damages. These results suggested that increased laminin-111 is a potential therapy for DMD. Laminin subunit beta 1 and laminin subunit gamma 1 are expressed in adult human muscle, but laminin subunit alpha 1 (LAMA1) gene is expressed only during embryogenesis. We thus developed an alternative method to laminin-111 protein repeated administration by inducing expression of the endogenous mouse Lama1 gene. This was done with the CRSPR/Cas9 system, i.e., by targeting the Lama1 promoter with one or several gRNAs and a dCas9 coupled with the VP160 transcription activation domain. Lama1 mRNA (qRT-PCR) and proteins (immunohistochemistry and western blot) were not detected in the control C2C12 myoblasts and in control muscles. However, significant expression was observed in cells transfected and in mouse muscles electroporated with plasmids coding for dCas9-VP160 and a gRNA. Larger synergic increases were observed by using two or three gRNAs. The increased Lama1 expression did not modify the expression of the α7 and β1 integrins. Increased expression of Lama1 by the CRISPR/Cas9 system will have to be further investigated by systemic delivery of the CRISPR/Cas9 components to verify whether this could be a treatment for several myopathies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

New Advanced Technologies in Stem Cell Therapy

DTIC Science & Technology

2014-11-01

6-8 wks old utrophin/dystrophin double knockout (dKO) mice, a severe animal model of DMD, have an excess of ectopic fat , calcium deposits and...tissues in skeletal muscle alter the tissue environment and induce deregulation of muscle homeostasis; however, the cellular origin of muscle fat ...as a major contributor to ectopic fat cell, calcium deposits and fibrotic tissue formation within dystrophic muscle. In the current study, we propose

A simplified immune suppression scheme leads to persistent micro-dystrophin expression in Duchenne muscular dystrophy dogs.

PubMed

Shin, Jin-Hong; Yue, Yongping; Srivastava, Arun; Smith, Bruce; Lai, Yi; Duan, Dongsheng

2012-02-01

Highly abbreviated micro-dystrophin genes have been intensively studied for Duchenne muscular dystrophy (DMD) gene therapy. Following adeno-associated virus (AAV) gene transfer, robust microgene expression is achieved in murine DMD models in the absence of immune suppression. Interestingly, a recent study suggests that AAV gene transfer in dystrophic dogs may require up to 18 weeks' immune suppression using a combination of three different immune-suppressive drugs (cyclosporine, mycophenolate mofetil, and anti-dog thymocyte globulin). Continued immune suppression is not only costly but also may cause untoward reactions. Further, some of the drugs (such as anti-dog thymocyte globulin) are not readily available. To overcome these limitations, we developed a novel 5-week immune suppression scheme using only cyclosporine and mycophenolate mofetil. AAV vectors (either AV.RSV.AP that expresses the heat-resistant human alkaline phosphatase gene, or AV.CMV.μDys that expresses the canine R16-17/H3/ΔC microgene) at 2.85×10(12) vg particles were injected into adult dystrophic dog limb muscles under the new immune suppression protocol. Sustained transduction was observed for nearly half year (the end of the study). The simplified immune suppression strategy described here may facilitate preclinical studies in the dog model.

Changes in intrinsic excitability of ganglion cells in degenerated retinas of RCS rats.

PubMed

Ren, Yi-Ming; Weng, Chuan-Huang; Zhao, Cong-Jian; Yin, Zheng-Qin

2018-01-01

To evaluate the intrinsic excitability of retinal ganglion cells (RGCs) in degenerated retinas. The intrinsic excitability of various morphologically defined RGC types using a combination of patch-clamp recording and the Lucifer yellow tracer in retinal whole-mount preparations harvested from Royal College of Surgeons (RCS) rats, a common retinitis pigmentosa (RP) model, in a relatively late stage of retinal degeneration (P90) were investigated. Several parameters of RGC morphologies and action potentials (APs) were measured and compared to those of non-dystrophic control rats, including dendritic stratification, dendritic field diameter, peak amplitude, half width, resting membrane potential, AP threshold, depolarization to threshold, and firing rates. Compared with non-dystrophic control RGCs, more depolarizations were required to reach the AP threshold in RCS RGCs with low spontaneous spike rates and in RCS OFF cells (especially A2o cells), and RCS RGCs maintained their dendritic morphologies, resting membrane potentials and capabilities to generate APs. RGCs are relatively well preserved morphologically and functionally, and some cells are more susceptible to decreased excitability during retinal degeneration. These findings provide valuable considerations for optimizing RP therapeutic strategies.

Collagen VII plays a dual role in wound healing

PubMed Central

Nyström, Alexander; Velati, Daniela; Mittapalli, Venugopal R.; Fritsch, Anja; Kern, Johannes S.; Bruckner-Tuderman, Leena

2013-01-01

Although a host of intracellular signals is known to contribute to wound healing, the role of the cell microenvironment in tissue repair remains elusive. Here we employed 2 different mouse models of genetic skin fragility to assess the role of the basement membrane protein collagen VII (COL7A1) in wound healing. COL7A1 secures the attachment of the epidermis to the dermis, and its mutations cause a human skin fragility disorder coined recessive dystrophic epidermolysis bullosa (RDEB) that is associated with a constant wound burden. We show that COL7A1 is instrumental for skin wound closure by 2 interconnected mechanisms. First, COL7A1 was required for re-epithelialization through organization of laminin-332 at the dermal-epidermal junction. Its loss perturbs laminin-332 organization during wound healing, which in turn abrogates strictly polarized expression of integrin α6β4 in basal keratinocytes and negatively impacts the laminin-332/integrin α6β4 signaling axis guiding keratinocyte migration. Second, COL7A1 supported dermal fibroblast migration and regulates their cytokine production in the granulation tissue. These findings, which were validated in human wounds, identify COL7A1 as a critical player in physiological wound healing in humans and mice and may facilitate development of therapeutic strategies not only for RDEB, but also for other chronic wounds. PMID:23867500

The Near Naked Hairless (HrN) Mutation Disrupts Hair Formation but is not Due to a Mutation in the Hairless Coding Region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yutao; Das, Suchita; Olszewski, Robert Edward

Near naked hairless (HrN) is a semi-dominant mutation that arose spontaneously and was suggested by allelism testing to be an allele of mouse Hairless (Hr). HrN mice differ from other Hr mutants in that hair loss appears as the postnatal coat begins to emerge, as opposed to failure to initiate the first postnatal hair cycle, and that the mutation displays semi-dominant inheritance. We sequenced the Hr cDNA in HrN/HrN mice and characterized the pathological and molecular phenotypes to identify the basis for hair loss in this model. HrN/HrN mice exhibit dystrophic hairs that are unable to consistently emerge from themore » hair follicle, while HrN/+ mice display a sparse coat of hair and a milder degree of follicular dystrophy than their homozygous littermates. DNA microarray analysis of cutaneous gene expression demonstrates that numerous genes are downregulated in HrN/HrN mice, primarily genes important for hair structure. By contrast, Hr expression is significantly increased. Sequencing the Hr coding region, intron-exon boundaries, 5'- and 3'- UTR and immediate upstream region did not reveal the underlying mutation. Therefore HrN does not appear to be an allele of Hr but may result from a mutation in a closely linked gene or from a regulatory mutation in Hr.« less

Seasonal mercury levels in phytoplankton and their relationship with algal biomass in two dystrophic shield lakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirkwood, A.E.; Chow-Fraser, P.; Mierle, G.

1999-03-01

This study focused on the seasonal dynamics of total Hg in the phytoplankton (living and dead) of two dystrophic shield lakes (Mouse and Ranger). Phytoplankton samples were taken from metalimnetic and hypolimnetic depths in the euphotic zone and were collected and analyzed using ultraclean techniques. In both lakes, phytoplankton Hg (PHYTO-Hg) levels (pg/L) in the metalimnion did not significantly change among dates over the season, although Ranger Lake exhibited significant differences between Hg values measured at the beginning and end of the season. In contrast, PHYTO-Hg significantly increased in the hypolimnia of both lakes by the end of the season.more » Combined influences of external Hg inputs, remineralization, phytoplankton sedimentation, and increased methylmercury production in the hypolimnia over the season may have contributed to these trends. A highly significant positive relationship existed between PHYTO-Hg levels and whole-water Hg levels, and the mean bioconcentration factor for Hg between the water column and phytoplankton was significantly higher in the hypolimnion compared to the metalimnion for both lakes. In most cases, parameters associated with algal biomass had significant positive correlations with PHYTO-Hg levels. Weight-specific PHYTO-Hg (pg/mg dry weight) varied significantly over the season, and there were interlake differences with respect to season trends. On the basis of these results, the authors recommend that the future sampling regimes include collection of phytoplankton at different limnetic depths through the season to account for spatial and temporal variations. Weight specific Hg levels in phytoplankton could not be explained well by the parameters tested, and the only significant regressions were with parameters reflecting algal biomass. This study provides in situ evidence of Hg accumulation in lake phytoplankton as a function of algal biomass on a seasonal basis and stresses the need to confirm these trends in other lake systems.« less

Age-dependent changes in diastolic Ca{sup 2+} and Na{sup +} concentrations in dystrophic cardiomyopathy: Role of Ca{sup 2+} entry and IP{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mijares, Alfredo; Altamirano, Francisco; Kolster, Juan

2014-10-03

Highlights: • Age-dependent increase in [Ca{sup 2+}]{sub d} and [Na{sup +}]{sub d} in mdx cardiomyocytes. • Gadolinium significantly reduced both [Ca{sup 2+}]{sub d} and [Na{sup +}]{sub d} at all ages. • IP{sub 3}-pathway inhibition reduced cations concentrations in dystrophic cardiomyocytes. - Abstract: Duchenne muscular dystrophy (DMD) is a lethal X-inherited disease caused by dystrophin deficiency. Besides the relatively well characterized skeletal muscle degenerative processes, DMD is also associated with a dilated cardiomyopathy that leads to progressive heart failure at the end of the second decade. The aim of the present study was to characterize the diastolic Ca{sup 2+} concentration ([Ca{supmore » 2+}]{sub d}) and diastolic Na{sup +} concentration ([Na{sup +}]{sub d}) abnormalities in cardiomyocytes isolated from 3-, 6-, 9-, and 12-month old mdx mice using ion-selective microelectrodes. In addition, the contributions of gadolinium (Gd{sup 3+})-sensitive Ca{sup 2+} entry and inositol triphosphate (IP{sub 3}) signaling pathways in abnormal [Ca{sup 2+}]{sub d} and [Na{sup +}]{sub d} were investigated. Our results showed an age-dependent increase in both [Ca{sup 2+}]{sub d} and [Na{sup +}]{sub d} in dystrophic cardiomyocytes compared to those isolated from age-matched wt mice. Gd{sup 3+} treatment significantly reduced both [Ca{sup 2+}]{sub d} and [Na{sup +}]{sub d} at all ages. In addition, blockade of the IP{sub 3}-pathway with either U-73122 or xestospongin C significantly reduced ion concentrations in dystrophic cardiomyocytes. Co-treatment with U-73122 and Gd{sup 3+} normalized both [Ca{sup 2+}]{sub d} and [Na{sup +}]{sub d} at all ages in dystrophic cardiomyocytes. These data showed that loss of dystrophin in mdx cardiomyocytes produced an age-dependent intracellular Ca{sup 2+} and Na{sup +} overload mediated at least in part by enhanced Ca{sup 2+} entry through Gd{sup 3+} sensitive transient receptor potential channels (TRPC), and by IP{sub 3} receptors.« less

Progressive nigrostriatal terminal dysfunction and degeneration in the engrailed1 heterozygous mouse model of Parkinson's disease.

PubMed

Nordströma, Ulrika; Beauvais, Geneviève; Ghosh, Anamitra; Pulikkaparambil Sasidharan, Baby Chakrapani; Lundblad, Martin; Fuchs, Julia; Joshi, Rajiv L; Lipton, Jack W; Roholt, Andrew; Medicetty, Satish; Feinstein, Timothy N; Steiner, Jennifer A; Escobar Galvis, Martha L; Prochiantz, Alain; Brundin, Patrik

2015-01-01

Current research on Parkinson's disease (PD) pathogenesis requires relevant animal models that mimic the gradual and progressive development of neuronal dysfunction and degeneration that characterizes the disease. Polymorphisms in engrailed 1 (En1), a homeobox transcription factor that is crucial for both the development and survival of mesencephalic dopaminergic neurons, are associated with sporadic PD. This suggests that En1 mutant mice might be a promising candidate PD model. Indeed, a mouse that lacks one En1 allele exhibits decreased mitochondrial complex I activity and progressive midbrain dopamine neuron degeneration in adulthood, both features associated with PD. We aimed to further characterize the disease-like phenotype of these En1(+/-) mice with a focus on early neurodegenerative changes that can be utilized to score efficacy of future disease modifying studies. We observed early terminal defects in the dopaminergic nigrostriatal pathway in En1(+/-) mice. Several weeks before a significant loss of dopaminergic neurons in the substantia nigra could be detected, we found that striatal terminals expressing high levels of dopaminergic neuron markers TH, VMAT2, and DAT were dystrophic and swollen. Using transmission electron microscopy, we identified electron dense bodies consistent with abnormal autophagic vacuoles in these terminal swellings. In line with these findings, we detected an up-regulation of the mTOR pathway, concurrent with a downregulation of the autophagic marker LC3B, in ventral midbrain and nigral dopaminergic neurons of the En1(+/-) mice. This supports the notion that autophagic protein degradation is reduced in the absence of one En1 allele. We imaged the nigrostriatal pathway using the CLARITY technique and observed many fragmented axons in the medial forebrain bundle of the En1(+/-) mice, consistent with axonal maintenance failure. Using in vivo electrochemistry, we found that nigrostriatal terminals in the dorsal striatum were severely deficient in dopamine release and reuptake. Our findings support a progressive retrograde degeneration of En1(+/-) nigrostriatal neurons, akin to what is suggested to occur in PD. We suggest that using the En1(+/-) mice as a model will provide further key insights into PD pathogenesis, and propose that axon terminal integrity and function can be utilized to estimate dopaminergic neuron health and efficacy of experimental PD therapies. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

A new therapeutic effect of simvastatin revealed by functional improvement in muscular dystrophy.

PubMed

Whitehead, Nicholas P; Kim, Min Jeong; Bible, Kenneth L; Adams, Marvin E; Froehner, Stanley C

2015-10-13

Duchenne muscular dystrophy (DMD) is a lethal, degenerative muscle disease with no effective treatment. DMD muscle pathogenesis is characterized by chronic inflammation, oxidative stress, and fibrosis. Statins, cholesterol-lowering drugs, inhibit these deleterious processes in ischemic diseases affecting skeletal muscle, and therefore have potential to improve DMD. However, statins have not been considered for DMD, or other muscular dystrophies, principally because skeletal-muscle-related symptoms are rare, but widely publicized, side effects of these drugs. Here we show positive effects of statins in dystrophic skeletal muscle. Simvastatin dramatically reduced damage and enhanced muscle function in dystrophic (mdx) mice. Long-term simvastatin treatment vastly improved overall muscle health in mdx mice, reducing plasma creatine kinase activity, an established measure of muscle damage, to near-normal levels. This reduction was accompanied by reduced inflammation, more oxidative muscle fibers, and improved strength of the weak diaphragm muscle. Shorter-term treatment protected against muscle fatigue and increased mdx hindlimb muscle force by 40%, a value comparable to current dystrophin gene-based therapies. Increased force correlated with reduced NADPH Oxidase 2 protein expression, the major source of oxidative stress in dystrophic muscle. Finally, in old mdx mice with severe muscle degeneration, simvastatin enhanced diaphragm force and halved fibrosis, a major cause of functional decline in DMD. These improvements were accompanied by autophagy activation, a recent therapeutic target for DMD, and less oxidative stress. Together, our findings highlight that simvastatin substantially improves the overall health and function of dystrophic skeletal muscles and may provide an unexpected, novel therapy for DMD and related neuromuscular diseases.

A new therapeutic effect of simvastatin revealed by functional improvement in muscular dystrophy

PubMed Central

Whitehead, Nicholas P.; Kim, Min Jeong; Bible, Kenneth L.; Adams, Marvin E.; Froehner, Stanley C.

2015-01-01

Duchenne muscular dystrophy (DMD) is a lethal, degenerative muscle disease with no effective treatment. DMD muscle pathogenesis is characterized by chronic inflammation, oxidative stress, and fibrosis. Statins, cholesterol-lowering drugs, inhibit these deleterious processes in ischemic diseases affecting skeletal muscle, and therefore have potential to improve DMD. However, statins have not been considered for DMD, or other muscular dystrophies, principally because skeletal-muscle-related symptoms are rare, but widely publicized, side effects of these drugs. Here we show positive effects of statins in dystrophic skeletal muscle. Simvastatin dramatically reduced damage and enhanced muscle function in dystrophic (mdx) mice. Long-term simvastatin treatment vastly improved overall muscle health in mdx mice, reducing plasma creatine kinase activity, an established measure of muscle damage, to near-normal levels. This reduction was accompanied by reduced inflammation, more oxidative muscle fibers, and improved strength of the weak diaphragm muscle. Shorter-term treatment protected against muscle fatigue and increased mdx hindlimb muscle force by 40%, a value comparable to current dystrophin gene-based therapies. Increased force correlated with reduced NADPH Oxidase 2 protein expression, the major source of oxidative stress in dystrophic muscle. Finally, in old mdx mice with severe muscle degeneration, simvastatin enhanced diaphragm force and halved fibrosis, a major cause of functional decline in DMD. These improvements were accompanied by autophagy activation, a recent therapeutic target for DMD, and less oxidative stress. Together, our findings highlight that simvastatin substantially improves the overall health and function of dystrophic skeletal muscles and may provide an unexpected, novel therapy for DMD and related neuromuscular diseases. PMID:26417069

Effect of genetic background on the dystrophic phenotype in mdx mice

PubMed Central

Coley, William D.; Bogdanik, Laurent; Vila, Maria Candida; Yu, Qing; Van Der Meulen, Jack H.; Rayavarapu, Sree; Novak, James S.; Nearing, Marie; Quinn, James L.; Saunders, Allison; Dolan, Connor; Andrews, Whitney; Lammert, Catherine; Austin, Andrew; Partridge, Terence A.; Cox, Gregory A.; Lutz, Cathleen; Nagaraju, Kanneboyina

2016-01-01

Genetic background significantly affects phenotype in multiple mouse models of human diseases, including muscular dystrophy. This phenotypic variability is partly attributed to genetic modifiers that regulate the disease process. Studies have demonstrated that introduction of the γ-sarcoglycan-null allele onto the DBA/2J background confers a more severe muscular dystrophy phenotype than the original strain, demonstrating the presence of genetic modifier loci in the DBA/2J background. To characterize the phenotype of dystrophin deficiency on the DBA/2J background, we created and phenotyped DBA/2J-congenic Dmdmdx mice (D2-mdx) and compared them with the original, C57BL/10ScSn-Dmdmdx (B10-mdx) model. These strains were compared with their respective control strains at multiple time points between 6 and 52 weeks of age. Skeletal and cardiac muscle function, inflammation, regeneration, histology and biochemistry were characterized. We found that D2-mdx mice showed significantly reduced skeletal muscle function as early as 7 weeks and reduced cardiac function by 28 weeks, suggesting that the disease phenotype is more severe than in B10-mdx mice. In addition, D2-mdx mice showed fewer central myonuclei and increased calcifications in the skeletal muscle, heart and diaphragm at 7 weeks, suggesting that their pathology is different from the B10-mdx mice. The new D2-mdx model with an earlier onset and more pronounced dystrophy phenotype may be useful for evaluating therapies that target cardiac and skeletal muscle function in dystrophin-deficient mice. Our data align the D2-mdx with Duchenne muscular dystrophy patients with the LTBP4 genetic modifier, making it one of the few instances of cross-species genetic modifiers of monogenic traits. PMID:26566673

Morphological changes in neurons of the hind limb reflex arc during long term immobilization

NASA Technical Reports Server (NTRS)

Tkachenko, Z. Y.

1980-01-01

Twelve adult rabbits were immobilized for 9 to 31 days, followed by histological study of the nerve processes of lumbar vertebra 7 and sacral vertebra 1, the sciatic nerve and the motor endings of the thigh muscles. In the spinal ganglia, dystrophic changes of increasing severity with immobilization time were found, including pericellular edema, vacuolized neuroplasm, pycnotic changes, cytolysis and destruction. Chromatophilic matter decreased and was partly bleached, and amitotic division occurred. A portion of the sciatic nerve fibers were argentophilic, and some fragmentary decomposition occurred. Considerable dystrophic changes occurred in the motor nerve endings.

[Characterization of a canine model of dystrophic bullous epidermolysis (DBE). Development of a gene therapy protocol].

PubMed

Magnol, Jean-Pierre; Pin, Didier; Palazzi, Xavier; Lacour, Jean-Philippe; Gache, Yannick; Meneguzzi, Guerrino

2005-01-01

The main human forms of epidermolysis bullosa (EB), namely EB simplex, junctional EB and dystrophic EB, have also been described in domestic animals (small and large ruminants, and horses) and companion animals (cats and dogs). A recent description of dystrophic epidermolysis bullosa (DEB) in Golden Retriever dogs provided details of the principal clinical, morphological and genetic features. The disease is characterized by blisters and erosions in the oral and esophageal epithelia, together with milia, nails dystrophy and growth retardation. The cutaneous lesions regress spontaneously in adult dogs, whereas the epithelial lesions persist, aggravate and spread, notably to the cornea. Classical microscopic studies (light and electron microscopy, indirect immunofluorescence) have revealed anchoring fibril abnormalities and very low-level and heterogenous expression of collagen type VII. The culprit mutation (G1906S) in the canine gene COL7A1 (87.8% nucleotide sequence identity to the human counterpart) involves the replacement of guanine 5716 by adenine, leading to glycine substitution by serine at amino acid position 1906. Transmission in kennels occurs in recessive mode (RDEB). These features recall certain human forms of DEB, and particularly those with a phenotype intermediate between gravis (the so-called Hallopeau-Siemens form) and mitis. No curative treatment of human EB is currently available, and efforts are therefore being made to develop a gene therapy protocol in animals. The first steps have already been successfully achieved, namely the development of a recombinant virus vector able to insert the wild-type gene into the keratinocyte genome, and grafting of artificial skin containing transfected canine keratinocytes in nude mice. The recombinant vectors are Moloney-type retroviruses (MMLV-PCMV), and the Zeocin resistance gene is used to select transduced cells. The artificial skin reconstructed in vitro is of the full-thickness type. Despite the large size of the transduced (9 kb), 95% of cells are transduced and produce large amounts of wild-type collagen. Two key issues remain, however: the possible immunogenicity of the transgene product and the persistence of transgene expression in individuals with a functional immune system. Golden Retriever dogs will provide a suitable animal model for these studies.

Increased Resting Intracellular Calcium Modulates NF-κB-dependent Inducible Nitric-oxide Synthase Gene Expression in Dystrophic mdx Skeletal Myotubes*

PubMed Central

Altamirano, Francisco; López, Jose R.; Henríquez, Carlos; Molinski, Tadeusz; Allen, Paul D.; Jaimovich, Enrique

2012-01-01

Duchenne muscular dystrophy (DMD) is a genetic disorder caused by dystrophin mutations, characterized by chronic inflammation and severe muscle wasting. Dystrophic muscles exhibit activated immune cell infiltrates, up-regulated inflammatory gene expression, and increased NF-κB activity, but the contribution of the skeletal muscle cell to this process has been unclear. The aim of this work was to study the pathways that contribute to the increased resting calcium ([Ca2+]rest) observed in mdx myotubes and its possible link with up-regulation of NF-κB and pro-inflammatory gene expression in dystrophic muscle cells. [Ca2+]rest was higher in mdx than in WT myotubes (308 ± 6 versus 113 ± 2 nm, p < 0.001). In mdx myotubes, both the inhibition of Ca2+ entry (low Ca2+ solution, Ca2+-free solution, and Gd3+) and blockade of either ryanodine receptors or inositol 1,4,5-trisphosphate receptors reduced [Ca2+]rest. Basal activity of NF-κB was significantly up-regulated in mdx versus WT myotubes. There was an increased transcriptional activity and p65 nuclear localization, which could be reversed when [Ca2+]rest was reduced. Levels of mRNA for TNFα, IL-1β, and IL-6 were similar in WT and mdx myotubes, whereas inducible nitric-oxide synthase (iNOS) expression was increased 5-fold. Reducing [Ca2+]rest using different strategies reduced iNOS gene expression presumably as a result of decreased activation of NF-κB. We propose that NF-κB, modulated by increased [Ca2+]rest, is constitutively active in mdx myotubes, and this mechanism can account for iNOS overexpression and the increase in reactive nitrogen species that promote damage in dystrophic skeletal muscle cells. PMID:22549782

Dystrophin-deficient pigs provide new insights into the hierarchy of physiological derangements of dystrophic muscle.

PubMed

Klymiuk, Nikolai; Blutke, Andreas; Graf, Alexander; Krause, Sabine; Burkhardt, Katinka; Wuensch, Annegret; Krebs, Stefan; Kessler, Barbara; Zakhartchenko, Valeri; Kurome, Mayuko; Kemter, Elisabeth; Nagashima, Hiroshi; Schoser, Benedikt; Herbach, Nadja; Blum, Helmut; Wanke, Rüdiger; Aartsma-Rus, Annemieke; Thirion, Christian; Lochmüller, Hanns; Walter, Maggie C; Wolf, Eckhard

2013-11-01

Duchenne muscular dystrophy (DMD) is caused by mutations in the X-linked dystrophin (DMD) gene. The absence of dystrophin protein leads to progressive muscle weakness and wasting, disability and death. To establish a tailored large animal model of DMD, we deleted DMD exon 52 in male pig cells by gene targeting and generated offspring by nuclear transfer. DMD pigs exhibit absence of dystrophin in skeletal muscles, increased serum creatine kinase levels, progressive dystrophic changes of skeletal muscles, impaired mobility, muscle weakness and a maximum life span of 3 months due to respiratory impairment. Unlike human DMD patients, some DMD pigs die shortly after birth. To address the accelerated development of muscular dystrophy in DMD pigs when compared with human patients, we performed a genome-wide transcriptome study of biceps femoris muscle specimens from 2-day-old and 3-month-old DMD and age-matched wild-type pigs. The transcriptome changes in 3-month-old DMD pigs were in good concordance with gene expression profiles in human DMD, reflecting the processes of degeneration, regeneration, inflammation, fibrosis and impaired metabolic activity. In contrast, the transcriptome profile of 2-day-old DMD pigs showed similarities with transcriptome changes induced by acute exercise muscle injury. Our studies provide new insights into early changes associated with dystrophin deficiency in a clinically severe animal model of DMD.

Loss of miR-29 in Myoblasts Contributes to Dystrophic Muscle Pathogenesis

PubMed Central

Wang, Lijun; Zhou, Liang; Jiang, Peiyong; Lu, Leina; Chen, Xiaona; Lan, Huiyao; Guttridge, Denis C; Sun, Hao; Wang, Huating

2012-01-01

microRNAs (miRNAs) are noncoding RNAs that regulate gene expression in post-transcriptional fashion, and emerging studies support their importance in a multitude of physiological and pathological processes. Here, we describe the regulation and function of miR-29 in Duchenne muscular dystrophy (DMD) and its potential use as therapeutic target. Our results demonstrate that miR-29 expression is downregulated in dystrophic muscles of mdx mice, a model of DMD. Restoration of its expression by intramuscular and intravenous injection improved dystrophy pathology by both promoting regeneration and inhibiting fibrogenesis. Mechanistic studies revealed that loss of miR-29 in muscle precursor cells (myoblasts) promotes their transdifferentiation into myofibroblasts through targeting extracellular molecules including collagens and microfibrillar-associated protein 5 (Mfap5). We further demonstrated that miR-29 is under negative regulation by transforming growth factor-β (TGF-β) signaling. Together, these results not only identify TGF-β–miR-29 as a novel regulatory axis during myoblasts conversion into myofibroblasts which constitutes a novel contributing route to muscle fibrogenesis of DMD but also implicate miR-29 replacement therapy as a promising treatment approach for DMD. PMID:22434133

Muscle ERRγ mitigates Duchenne muscular dystrophy via metabolic and angiogenic reprogramming.

PubMed

Matsakas, Antonios; Yadav, Vikas; Lorca, Sabina; Narkar, Vihang

2013-10-01

Treatment of Duchenne muscular dystrophy (DMD) by replacing mutant dystrophin or restoring dystrophin-associated glycoprotein complex (DAG) has been clinically challenging. Instead, identifying and targeting muscle pathways deregulated in DMD will provide new therapeutic avenues. We report that the expression of nuclear receptor estrogen-related receptor-γ (ERRγ), and its metabolic and angiogenic targets are down-regulated (50-85%) in skeletal muscles of mdx mice (DMD model) vs. wild-type mice. Corelatively, oxidative myofibers, muscle vasculature, and exercise tolerance (33%) are decreased in mdx vs. wild-type mice. Overexpressing ERRγ selectively in the dystrophic muscles of the mdx mice restored metabolic and angiogenic gene expression compared with control mdx mice. Further, ERRγ enhanced muscle oxidative myofibers, vasculature, and blood flow (by 33-66%) and improved exercise tolerance (by 75%) in the dystrophic mice. Restoring muscle ERRγ pathway ameliorated muscle damage and also prevented DMD hallmarks of postexercise muscle damage, hypoxia, and fatigue in mdx mice. Notably, ERRγ did not restore sarcolemmal DAG complex, which is thus dispensable for antidystrophic effects of ERRγ. In summary, ERRγ-dependent metabolic and angiogenic gene program is defective in DMD, and we demonstrate that its restoration is a potential strategy for treating muscular dystrophy.

Changes in intrinsic excitability of ganglion cells in degenerated retinas of RCS rats

PubMed Central

Ren, Yi-Ming; Weng, Chuan-Huang; Zhao, Cong-Jian; Yin, Zheng-Qin

2018-01-01

AIM To evaluate the intrinsic excitability of retinal ganglion cells (RGCs) in degenerated retinas. METHODS The intrinsic excitability of various morphologically defined RGC types using a combination of patch-clamp recording and the Lucifer yellow tracer in retinal whole-mount preparations harvested from Royal College of Surgeons (RCS) rats, a common retinitis pigmentosa (RP) model, in a relatively late stage of retinal degeneration (P90) were investigated. Several parameters of RGC morphologies and action potentials (APs) were measured and compared to those of non-dystrophic control rats, including dendritic stratification, dendritic field diameter, peak amplitude, half width, resting membrane potential, AP threshold, depolarization to threshold, and firing rates. RESULTS Compared with non-dystrophic control RGCs, more depolarizations were required to reach the AP threshold in RCS RGCs with low spontaneous spike rates and in RCS OFF cells (especially A2o cells), and RCS RGCs maintained their dendritic morphologies, resting membrane potentials and capabilities to generate APs. CONCLUSION RGCs are relatively well preserved morphologically and functionally, and some cells are more susceptible to decreased excitability during retinal degeneration. These findings provide valuable considerations for optimizing RP therapeutic strategies. PMID:29862172

Losartan enhances the success of myoblast transplantation.

PubMed

Fakhfakh, Raouia; Lamarre, Yann; Skuk, Daniel; Tremblay, Jacques P

2012-01-01

Duchenne muscular dystrophy is a recessive X-linked genetic disease caused by dystrophin gene mutations. Cell therapy can be a potential approach aiming to introduce a functional dystrophin in the dystrophic patient myofibers. However, this strategy produced so far limited results. Transforming growth factor-β (TGF-β) is a negative regulator of skeletal muscle development and is responsible for limiting myogenic regeneration. The combination of TGF-β signaling inhibition with myoblast transplantation can be an effective therapeutic approach in dystrophin-deficient patients. Our aim was to verify whether the success of human myoblast transplantation in immunodeficient dystrophic mice is enhanced with losartan, a molecule that downregulates TGF-β expression. In vitro, blocking TGF-β activity with losartan increased proliferation and fusion and decreased apoptosis in human myoblasts. In vivo, human myoblasts were transplanted in mice treated with oral losartan. Immunodetection of human dystrophin in tibialis anterior cross sections 1 month posttransplantation revealed more human dystrophin-positive myofibers in these mice than in nontreated dystrophic mice. Thus, blocking the TGF-β signal with losartan treatment improved the success of myoblast transplantation probably by increasing myoblast proliferation and fusion, decreasing macrophage activation, and changing the expression of myogenic regulator factors.

Dystrophic Calcification in the Epidural and Extraforaminal Space Caused by Repetitive Triamcinolone Acetonide Injections

PubMed Central

Chung, Sang-Bong; Kim, Ki-Jeong; Kim, Hyun-Jib

2011-01-01

The authors report a case of epidural and extraforaminal calcification caused by repetitive triamcinolone acetonide injections. A 66-year-old woman was admitted presenting with lower extremity weakness and radiating pain in her left leg. Ten months before admission, the patient was diagnosed as having an L4-5 spinal stenosis and underwent anterior lumbar interbody fusion followed by posterior fixation. Her symptoms had been sustained and she did not respond to transforaminal steroid injections. Repetitive injections (10 times) had been performed on the L4-5 level for six months. She had been taking bisphosphonate as an antiresorptive agent for ten months after surgery. Calcification in the ventral epidural and extraforaminal space was detected. The gritty particles were removed during decompressive surgery and these were proven to be a dystrophic calcification. The patient recovered from weakness and radiating leg pain. Repetitive triamcinolone acetonide injections after discectomy may be the cause of dystrophic calcification not only in the degenerated residual disc, but also in the posterior longitudinal ligament. Possible mechanisms may include the toxicity of preservatives and the insolubility of triamcinolone acetonide. We should consider that repetitive triamcinolone injections in the postdisectomy state may cause intraspinal ossification and calcification. PMID:22053235

Neuromuscular imaging in inherited muscle diseases

PubMed Central

Kley, Rudolf A.; Fischer, Dirk

2010-01-01

Driven by increasing numbers of newly identified genetic defects and new insights into the field of inherited muscle diseases, neuromuscular imaging in general and magnetic resonance imaging (MRI) in particular are increasingly being used to characterise the severity and pattern of muscle involvement. Although muscle biopsy is still the gold standard for the establishment of the definitive diagnosis, muscular imaging is an important diagnostic tool for the detection and quantification of dystrophic changes during the clinical workup of patients with hereditary muscle diseases. MRI is frequently used to describe muscle involvement patterns, which aids in narrowing of the differential diagnosis and distinguishing between dystrophic and non-dystrophic diseases. Recent work has demonstrated the usefulness of muscle imaging for the detection of specific congenital myopathies, mainly for the identification of the underlying genetic defect in core and centronuclear myopathies. Muscle imaging demonstrates characteristic patterns, which can be helpful for the differentiation of individual limb girdle muscular dystrophies. The aim of this review is to give a comprehensive overview of current methods and applications as well as future perspectives in the field of neuromuscular imaging in inherited muscle diseases. We also provide diagnostic algorithms that might guide us through the differential diagnosis in hereditary myopathies. PMID:20422195

Acetylcholine receptor distribution and synapse elimination at the developing neuromuscular junction of mdx mice.

PubMed

Minatel, Elaine; Neto, Humberto Santo; Marques, Maria Julia

2003-11-01

The pattern of innervation of the vertebrate neuromuscular junction is established during early development, when junctions go from multiple to single innervation in the phenomenon of synapse elimination, suggesting that changes at the molecular level in the postsynaptic cell lead to the removal of nerve terminals. The mdx mouse is deficient in dystrophin and associated proteins that are part of the postsynaptic cytoskeleton. We used rhodamine-alpha-bungarotoxin and anti-neurofilament IgG-FITC to stain acetylcholine receptors and nerve terminals of the sternomastoid muscle during postnatal development in mdx and control C57BL/10 mice. Using fluorescence confocal microscopy, we observed that, 7 days after birth, 86.7% of the endplates of mdx mice were monoinnervated (n = 200) compared with 41.4% in control mice (n = 200). By the end of the second postnatal week, all endplates were innervated singly (100% mdx and 94.7% controls, n = 200 per group). These results show that dystrophic fibers achieve single innervation earlier, perhaps because dystrophin or a normal cytoskeletal complex is implicated in this phenomenon.

Potent pro-inflammatory and pro-fibrotic molecules, osteopontin and galectin-3, are not major disease modulators of laminin α2 chain-deficient muscular dystrophy

PubMed Central

Gawlik, Kinga I.; Holmberg, Johan; Svensson, Martina; Einerborg, Mikaela; Oliveira, Bernardo M. S.; Deierborg, Tomas; Durbeej, Madeleine

2017-01-01

A large number of human diseases are caused by chronic tissue injury with fibrosis potentially leading to organ failure. There is a need for more effective anti-fibrotic therapies. Congenital muscular dystrophy type 1A (MDC1A) is a devastating form of muscular dystrophy caused by laminin α2 chain-deficiency. It is characterized with early inflammation and build-up of fibrotic lesions, both in patients and MDC1A mouse models (e.g. dy3K/dy3K). Despite the enormous impact of inflammation on tissue remodelling in disease, the inflammatory response in MDC1A has been poorly described. Consequently, a comprehensive understanding of secondary mechanisms (impaired regeneration, enhanced fibrosis) leading to deterioration of muscle phenotype in MDC1A is missing. We have monitored inflammatory processes in dy3K/dy3K muscle and created mice deficient in laminin α2 chain and osteopontin or galectin-3, two pro-inflammatory and pro-fibrotic molecules drastically increased in dystrophic muscle. Surprisingly, deletion of osteopontin worsened the phenotype of dy3K/dy3K mice and loss of galectin-3 did not reduce muscle pathology. Our results indicate that osteopontin could even be a beneficial immunomodulator in MDC1A. This knowledge is essential for the design of future therapeutic interventions for muscular dystrophies that aim at targeting inflammation, especially that osteopontin inhibition has been suggested for Duchenne muscular dystrophy therapy. PMID:28281577

Effects of dietary omega-3 on dystrophic cardiac and diaphragm muscles as evaluated by 1H magnetic resonance spectroscopy: Metabolic profile and calcium-related proteins.

PubMed

Maurício, Adriana Fogagnolo; de Carvalho, Samara Camaçari; Santo Neto, Humberto; Marques, Maria Julia

2017-08-01

Duchenne muscular dystrophy (DMD) is characterized by the absence of dystrophin and muscle degeneration. Calcium dysregulation and oxidative stress also contribute to the disease progression. We evaluated the potential therapeutic benefits of supplementation with omega-3 on the metabolic profile, calcium-related proteins and oxidative stress response in the heart and diaphragm (DIA) of the mdx mouse model of DMD at later stages of the disease (13 months). Mdx mice (8 months old) received omega-3 via a dietary supplement for 5 months. Metabolites were analyzed by 1 H magnetic resonance spectroscopy. Muscle total calcium was evaluated by inductively coupled plasma-optical emission spectrometry. Calsequestrin, TRPC1 and 4-HNE were determined via Western blot. Omega-3 decreased the metabolites taurine (related to calcium regulation and oxidative stress), aspartate (related to inflammation) and oxypurinol (related to oxidative stress) in the heart (aspartate) and DIA (taurine, aspartate and oxypurinol). Omega-3 also significantly decreased total calcium and TRPC1 levels in cardiac and DIA muscles and increased the levels of calsequestrin (cardiac and skeletal) and decreased the oxidative stress marker 4-HNE. The current study suggests that supplementation with omega-3 may generate therapeutic benefits on dystrophy progression, at later stages of the disease, with changes in the metabolic profile that may be correlated to omega-3 therapy. Copyright © 2017 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

Oxidative stress and pathology in muscular dystrophies: focus on protein thiol oxidation and dysferlinopathies.

PubMed

Terrill, Jessica R; Radley-Crabb, Hannah G; Iwasaki, Tomohito; Lemckert, Frances A; Arthur, Peter G; Grounds, Miranda D

2013-09-01

The muscular dystrophies comprise more than 30 clinical disorders that are characterized by progressive skeletal muscle wasting and degeneration. Although the genetic basis for many of these disorders has been identified, the exact mechanism for pathogenesis generally remains unknown. It is considered that disturbed levels of reactive oxygen species (ROS) contribute to the pathology of many muscular dystrophies. Reactive oxygen species and oxidative stress may cause cellular damage by directly and irreversibly damaging macromolecules such as proteins, membrane lipids and DNA; another major cellular consequence of reactive oxygen species is the reversible modification of protein thiol side chains that may affect many aspects of molecular function. Irreversible oxidative damage of protein and lipids has been widely studied in Duchenne muscular dystrophy, and we have recently identified increased protein thiol oxidation in dystrophic muscles of the mdx mouse model for Duchenne muscular dystrophy. This review evaluates the role of elevated oxidative stress in Duchenne muscular dystrophy and other forms of muscular dystrophies, and presents new data that show significantly increased protein thiol oxidation and high levels of lipofuscin (a measure of cumulative oxidative damage) in dysferlin-deficient muscles of A/J mice at various ages. The significance of this elevated oxidative stress and high levels of reversible thiol oxidation, but minimal myofibre necrosis, is discussed in the context of the disease mechanism for dysferlinopathies, and compared with the situation for dystrophin-deficient mdx mice. © 2013 The Authors Journal compilation © 2013 FEBS.

NAD+ Biosynthesis Ameliorates a Zebrafish Model of Muscular Dystrophy

PubMed Central

Goody, Michelle F.; Kelly, Meghan W.; Reynolds, Christine J.; Khalil, Andre; Crawford, Bryan D.; Henry, Clarissa A.

2012-01-01

Muscular dystrophies are common, currently incurable diseases. A subset of dystrophies result from genetic disruptions in complexes that attach muscle fibers to their surrounding extracellular matrix microenvironment. Cell-matrix adhesions are exquisite sensors of physiological conditions and mediate responses that allow cells to adapt to changing conditions. Thus, one approach towards finding targets for future therapeutic applications is to identify cell adhesion pathways that mediate these dynamic, adaptive responses in vivo. We find that nicotinamide riboside kinase 2b-mediated NAD+ biosynthesis, which functions as a small molecule agonist of muscle fiber-extracellular matrix adhesion, corrects dystrophic phenotypes in zebrafish lacking either a primary component of the dystrophin-glycoprotein complex or integrin alpha7. Exogenous NAD+ or a vitamin precursor to NAD+ reduces muscle fiber degeneration and results in significantly faster escape responses in dystrophic embryos. Overexpression of paxillin, a cell adhesion protein downstream of NAD+ in this novel cell adhesion pathway, reduces muscle degeneration in zebrafish with intact integrin receptors but does not improve motility. Activation of this pathway significantly increases organization of laminin, a major component of the extracellular matrix basement membrane. Our results indicate that the primary protective effects of NAD+ result from changes to the basement membrane, as a wild-type basement membrane is sufficient to increase resilience of dystrophic muscle fibers to damage. The surprising result that NAD+ supplementation ameliorates dystrophy in dystrophin-glycoprotein complex– or integrin alpha7–deficient zebrafish suggests the existence of an additional laminin receptor complex that anchors muscle fibers to the basement membrane. We find that integrin alpha6 participates in this pathway, but either integrin alpha7 or the dystrophin-glycoprotein complex is required in conjunction with integrin alpha6 to reduce muscle degeneration. Taken together, these results define a novel cell adhesion pathway that may have future therapeutic relevance for a broad spectrum of muscular dystrophies. PMID:23109907

Dysfunctional Muscle and Liver Glycogen Metabolism in mdx Dystrophic Mice

PubMed Central

Stapleton, David I.; Lau, Xianzhong; Flores, Marcelo; Trieu, Jennifer; Gehrig, Stefan M.; Chee, Annabel; Naim, Timur; Lynch, Gordon S.; Koopman, René

2014-01-01

Background Duchenne muscular dystrophy (DMD) is a severe, genetic muscle wasting disorder characterised by progressive muscle weakness. DMD is caused by mutations in the dystrophin (dmd) gene resulting in very low levels or a complete absence of the dystrophin protein, a key structural element of muscle fibres which is responsible for the proper transmission of force. In the absence of dystrophin, muscle fibres become damaged easily during contraction resulting in their degeneration. DMD patients and mdx mice (an animal model of DMD) exhibit altered metabolic disturbances that cannot be attributed to the loss of dystrophin directly. We tested the hypothesis that glycogen metabolism is defective in mdx dystrophic mice. Results Dystrophic mdx mice had increased skeletal muscle glycogen (79%, (P<0.01)). Skeletal muscle glycogen synthesis is initiated by glycogenin, the expression of which was increased by 50% in mdx mice (P<0.0001). Glycogen synthase activity was 12% higher (P<0.05) but glycogen branching enzyme activity was 70% lower (P<0.01) in mdx compared with wild-type mice. The rate-limiting enzyme for glycogen breakdown, glycogen phosphorylase, had 62% lower activity (P<0.01) in mdx mice resulting from a 24% reduction in PKA activity (P<0.01). In mdx mice glycogen debranching enzyme expression was 50% higher (P<0.001) together with starch-binding domain protein 1 (219% higher; P<0.01). In addition, mdx mice were glucose intolerant (P<0.01) and had 30% less liver glycogen (P<0.05) compared with control mice. Subsequent analysis of the enzymes dysregulated in skeletal muscle glycogen metabolism in mdx mice identified reduced glycogenin protein expression (46% less; P<0.05) as a possible cause of this phenotype. Conclusion We identified that mdx mice were glucose intolerant, and had increased skeletal muscle glycogen but reduced amounts of liver glycogen. PMID:24626262

Functional and molecular effects of arginine butyrate and prednisone on muscle and heart in the mdx mouse model of Duchenne Muscular Dystrophy.

PubMed

Guerron, Alfredo D; Rawat, Rashmi; Sali, Arpana; Spurney, Christopher F; Pistilli, Emidio; Cha, Hee-Jae; Pandey, Gouri S; Gernapudi, Ramkishore; Francia, Dwight; Farajian, Viken; Escolar, Diana M; Bossi, Laura; Becker, Magali; Zerr, Patricia; de la Porte, Sabine; Gordish-Dressman, Heather; Partridge, Terence; Hoffman, Eric P; Nagaraju, Kanneboyina

2010-06-21

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. 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. 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.

Functional and Molecular Effects of Arginine Butyrate and Prednisone on Muscle and Heart in the mdx Mouse Model of Duchenne Muscular Dystrophy

PubMed Central

Guerron, Alfredo D.; Rawat, Rashmi; Sali, Arpana; Spurney, Christopher F.; Pistilli, Emidio; Cha, Hee-Jae; Pandey, Gouri S.; Gernapudi, Ramkishore; Francia, Dwight; Farajian, Viken; Escolar, Diana M.; Bossi, Laura; Becker, Magali; Zerr, Patricia; de la Porte, Sabine; Gordish-Dressman, Heather; Partridge, Terence; Hoffman, Eric P.; Nagaraju, Kanneboyina

2010-01-01

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. PMID:20574530

[Biochemical evaluation of metabolic disorders in the tissues of the locomotor system in patients with occupational diseases caused by physical stress].

PubMed

Shatskaia, N N; Tarasova, A A; Fedorova, V I; Shardakova, E F; Selezneva, A I; Fedosova, N F

1991-01-01

A group of patients with occupational disease and female sewing-machine operators were medically examined with a broad set of biochemical techniques aimed at the detection of metabolic disorders in the locomotor system tissues. Noninflammatory dystrophic changes were found. The muscular component was dominating in comparison with the osseous one in the genesis of the degenerative dystrophic processes, which manifested in the clinical course. Laboratory manifestations were revealed related to the lowered energy supply and oxygenation of the skeleton muscles in patients with neuromuscular and osteo-muscular++ syndromes. The metabolic disorders were diagnosed at the early stages of myalgia.

A Duchenne Muscular Dystrophy Gene Hot Spot Mutation in Dystrophin-Deficient Cavalier King Charles Spaniels Is Amenable to Exon 51 Skipping

PubMed Central

Walmsley, Gemma L.; Arechavala-Gomeza, Virginia; Fernandez-Fuente, Marta; Burke, Margaret M.; Nagel, Nicole; Holder, Angela; Stanley, Rachael; Chandler, Kate; Marks, Stanley L.; Muntoni, Francesco; Shelton, G. Diane; Piercy, Richard J.

2010-01-01

Background Duchenne muscular dystrophy (DMD), which afflicts 1 in 3500 boys, is one of the most common genetic disorders of children. This fatal degenerative condition is caused by an absence or deficiency of dystrophin in striated muscle. Most affected patients have inherited or spontaneous deletions in the dystrophin gene that disrupt the reading frame resulting in unstable truncated products. For these patients, restoration of the reading frame via antisense oligonucleotide-mediated exon skipping is a promising therapeutic approach. The major DMD deletion “hot spot” is found between exons 45 and 53, and skipping exon 51 in particular is predicted to ameliorate the dystrophic phenotype in the greatest number of patients. Currently the mdx mouse is the most widely used animal model of DMD, although its mild phenotype limits its suitability in clinical trials. The Golden Retriever muscular dystrophy (GRMD) model has a severe phenotype, but due to its large size, is expensive to use. Both these models have mutations in regions of the dystrophin gene distant from the commonly mutated DMD “hot spot”. Methodology/Principal Findings Here we describe the severe phenotype, histopathological findings, and molecular analysis of Cavalier King Charles Spaniels with dystrophin-deficient muscular dystrophy (CKCS-MD). The dogs harbour a missense mutation in the 5′ donor splice site of exon 50 that results in deletion of exon 50 in mRNA transcripts and a predicted premature truncation of the translated protein. Antisense oligonucleotide-mediated skipping of exon 51 in cultured myoblasts from an affected dog restored the reading frame and protein expression. Conclusions/Significance Given the small size of the breed, the amiable temperament and the nature of the mutation, we propose that CKCS-MD is a valuable new model for clinical trials of antisense oligonucleotide-induced exon skipping and other therapeutic approaches for DMD. PMID:20072625

Acetylcholine, GABA and neuronal networks: a working hypothesis for compensations in the dystrophic brain.

PubMed

Cohen, Erez James; Quarta, Eros; Fulgenzi, Gianluca; Minciacchi, Diego

2015-01-01

Duchenne muscular dystrophy (DMD), a genetic disease arising from a mutation in the dystrophin gene, is characterized by muscle failure and is often associated with cognitive deficits. Studies of the dystrophic brain on the murine mdx model of DMD provide evidence of morphological and functional alterations in the central nervous system (CNS) possibly compatible with the cognitive impairment seen in DMD. However, while some of the alterations reported are a direct consequence of the absence of dystrophin, others seem to be associated only indirectly. In this review we reevaluate the literature in order to formulate a possible explanation for the cognitive impairments associated with DMD. We present a working hypothesis, demonstrated as an integrated neuronal network model, according to which within the cascade of events leading to cognitive impairments there are compensatory mechanisms aimed to maintain functional stability via perpetual adjustments of excitatory and inhibitory components. Such ongoing compensatory response creates continuous perturbations that disrupt neuronal functionality in terms of network efficiency. We have theorized that in this process acetylcholine and network oscillations play a central role. A better understating of these mechanisms could provide a useful diagnostic index of the disease's progression and, perhaps, the correct counterbalance of this process might help to prevent deterioration of the CNS in DMD. Furthermore, the involvement of compensatory mechanisms in the CNS could be extended beyond DMD and possibly help to clarify other physio-pathological processes of the CNS. Copyright © 2014 Elsevier Inc. All rights reserved.

Genome-wide association study to identify potential genetic modifiers in a canine model for Duchenne muscular dystrophy.

PubMed

Brinkmeyer-Langford, Candice; Balog-Alvarez, Cynthia; Cai, James J; Davis, Brian W; Kornegay, Joe N

2016-08-22

Duchenne muscular dystrophy (DMD) causes progressive muscle degeneration, cardiomyopathy and respiratory failure in approximately 1/5,000 boys. Golden Retriever muscular dystrophy (GRMD) resembles DMD both clinically and pathologically. Like DMD, GRMD exhibits remarkable phenotypic variation among affected dogs, suggesting the influence of modifiers. Understanding the role(s) of genetic modifiers of GRMD may identify genes and pathways that also modify phenotypes in DMD and reveal novel therapies. Therefore, our objective in this study was to identify genetic modifiers that affect discrete GRMD phenotypes. We performed a linear mixed-model (LMM) analysis using 16 variably-affected dogs from our GRMD colony (8 dystrophic, 8 non-dystrophic). All of these dogs were either full or half-siblings, and phenotyped for 19 objective, quantitative biomarkers at ages 6 and 12 months. Each biomarker was individually assessed. Gene expression profiles of 59 possible candidate genes were generated for two muscle types: the cranial tibialis and medial head of the gastrocnemius. SNPs significantly associated with GRMD biomarkers were identified on multiple chromosomes (including the X chromosome). Gene expression levels for candidate genes located near these SNPs correlated with biomarker values, suggesting possible roles as GRMD modifiers. The results of this study enhance our understanding of GRMD pathology and represent a first step toward the characterization of GRMD modifiers that may be relevant to DMD pathology. Such modifiers are likely to be useful for DMD treatment development based on their relationships to GRMD phenotypes.

Dystrophin restoration therapy improves both the reduced excitability and the force drop induced by lengthening contractions in dystrophic mdx skeletal muscle.

PubMed

Roy, Pauline; Rau, Fredérique; Ochala, Julien; Messéant, Julien; Fraysse, Bodvael; Lainé, Jeanne; Agbulut, Onnik; Butler-Browne, Gillian; Furling, Denis; Ferry, Arnaud

2016-01-01

The greater susceptibility to contraction-induced skeletal muscle injury (fragility) is an important dystrophic feature and tool for testing preclinic dystrophin-based therapies for Duchenne muscular dystrophy. However, how these therapies reduce the muscle fragility is not clear. To address this question, we first determined the event(s) of the excitation-contraction cycle which is/are altered following lengthening (eccentric) contractions in the mdx muscle. We found that the immediate force drop following lengthening contractions, a widely used measure of muscle fragility, was associated with reduced muscle excitability. Moreover, the force drop can be mimicked by an experimental reduction in muscle excitation of uninjured muscle. Furthermore, the force drop was not related to major neuromuscular transmission failure, excitation-contraction uncoupling, and myofibrillar impairment. Secondly, and importantly, the re-expression of functional truncated dystrophin in the muscle of mdx mice using an exon skipping strategy partially prevented the reductions in both force drop and muscle excitability following lengthening contractions. We demonstrated for the first time that (i) the increased susceptibility to contraction-induced muscle injury in mdx mice is mainly attributable to reduced muscle excitability; (ii) dystrophin-based therapy improves fragility of the dystrophic skeletal muscle by preventing reduction in muscle excitability.

A novel quantitative morphometry approach to assess regeneration in dystrophic skeletal muscle.

PubMed

Buttgereit, Andreas; Weber, Cornelia; Friedrich, Oliver

2014-07-01

Duchenne muscular dystrophy is an inherited degenerative muscle disease with progressive weakness of skeletal and cardiac muscle. Disturbed calcium homeostasis and signalling pathways result in degeneration/regeneration cycles with fibrotic remodelling of muscle tissue, sustained by chronic inflammation. In addition to altered microarchitecture, regeneration in dystrophic muscle fibres is often only classified by centrally located nuclei but correlation of the regeneration process to nuclear volumes, myosin amounts, architecture and functional quality are missing, in particular in old muscles where the regenerative capacity is exhausted. Such information could yield novel regeneration-to-function biomarkers. Here we used second harmonic generation and multi photon fluorescence microscopy in intact single muscle fibres from wild-type, dystrophic mdx and transgenic mdx mice expressing an Δex 17-48 mini-dystrophin to determine the percentage of centronucleated fibres and nucleus-to-myosin volume ratio as a function of age. Based on this ratio we define a 'biomotoric efficiency' as an optical measure for fibre maturation, which is close to unity in adult wild-type and mini-dystrophin fibres, but smaller in very young and old mdx mice as a result of ongoing cell maturation (young) and regeneration (aged). With these parameters it is possible to provide a quantitative measure about muscle fibre regeneration. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison of Outcomes in 3 Surgical Approaches for Dystrophic Cervical Kyphosis in Patients with Neurofibromatosis 1.

PubMed

Lin, Tao; Shao, Wei; Zhang, Ke; Gao, Rui; Zhou, Xuhui

2018-03-01

To compare outcomes of anterior-only (AO), posterior-only (PO), and anteroposterior (AP) surgical approaches for treatment of dystrophic cervical kyphosis in patients with neurofibromatosis 1 (NF1). This retrospective observational study included 81 patients with dystrophic cervical kyphosis secondary to NF1. Length of kyphosis, duration of halo traction, Cobb angle, C2-7-sagittal vertical axis (SVA), T1 slope, Neck Disability Index score, and postoperative complications were evaluated before and, if possible, after each surgical approach. AP approach provided the best outcomes (average spinal Cobb angle was corrected from 61.2 ± 9.1° to 5.7 ± 3.2°, P < 0.05); there was no significant difference between AO and PO approaches (P > 0.05). With regard to cervical sagittal balance, AP approach had the most improvements of C2-7-SVA (mean C2-7-SVA was corrected from 3.2 ± 9.2 mm to 12.8 ± 2.6 mm, P < 0.05); the difference between AO and PO approaches was not significant (P > 0.05). T1 slope results were similar to C2-7-SVA. Neck Disability Index score of all patients improved significantly after surgery (P < 0.05); specifically, patients who had an AP approach constituted the largest portion of the satisfied patient group. Postoperative junctional kyphosis occurred in 11 patients (1 AP approach, 6 AO approach, 4 PO approach); these findings correlated with patients with ≤5 fused segments. AP approach surgery provided the best correction of dystrophic cervical kyphosis and sagittal balance for patients with NF1. Patients undergoing an AP approach were more satisfied with their outcomes. Junctional kyphosis can be prevented effectively using an AP approach in patients with >5 fused segments. Copyright © 2017 Elsevier Inc. All rights reserved.

Intramuscular renin-angiotensin system is activated in human muscular dystrophy.

PubMed

Sun, Guilian; Haginoya, Kazuhiro; Dai, Hongmei; Chiba, Yoko; Uematsu, Mitsugu; Hino-Fukuyo, Naomi; Onuma, Akira; Iinuma, Kazuie; Tsuchiya, Shigeru

2009-05-15

To investigate the role of the muscular renin-angiotensin system (RAS) in human muscular dystrophy, we used immunohistochemistry and Western blotting to examine the cellular localization of angiotensin-converting enzyme (ACE), the angiotensin II type 1 receptor (AT1) and the angiotensin II type 2 receptor (AT2) in muscle biopsies from patients with Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and congenital muscular dystrophy (CMD). In normal muscle, ACE was expressed in vascular endothelial cells and neuromuscular junctions (NMJs), whereas AT1 was immunolocalized to the smooth muscle cells of blood vessels and intramuscular nerve twigs. AT2 was immunolocalized in the smooth muscle cells of blood vessels. These findings suggest that the RAS has a functional role in peripheral nerves and NMJs. ACE and AT1, but AT2 immunoreactivity were increased markedly in dystrophic muscle as compared to controls. ACE and the AT1 were strongly expressed in the cytoplasm and nuclei of regenerating muscle fibers, fibroblasts, and in macrophages infiltrating necrotic fibers. Double immunolabeling revealed that activated fibroblasts in the endomysium and perimysium of DMD and CMD muscle were positive for ACE and AT1. Triple immunolabeling demonstrated that transforming growth factor-beta1 (TGF-beta1) and ACE were colocalized on the cytoplasm of activated fibroblasts in dystrophic muscle. Furthermore, Western blotting showed increases in the expression of AT1 and TGF-beta1 protein in dystrophic muscle, which coincided with our immunohistochemical results. The overexpression of ACE and AT1 in dystrophic muscle would likely result in the increased production of Ang II, which may act on these cells in an autocrine manner via AT1. The activation of AT1 may induce fibrous tissue formation through overexpression of TGF-beta1, which potently activates fibrogenesis and suppresses regeneration. In conclusion, our results imply that the intramuscular RAS-TGF-beta1 pathway is activated in human muscular dystrophy and plays a role at least partly in the pathophysiology of this disease.

Effect of higher implant density on curve correction in dystrophic thoracic scoliosis secondary to neurofibromatosis Type 1.

PubMed

Li, Yang; Yuan, Xinxin; Sha, Shifu; Liu, Zhen; Zhu, Weiguo; Qiu, Yong; Wang, Bin; Yu, Yang; Zhu, Zezhang

2017-10-01

OBJECTIVE The aim of this study was to investigate how implant density affects radiographic results and clinical outcomes in patients with dystrophic scoliosis secondary to neurofibromatosis Type 1 (NF1). METHODS A total of 41 patients with dystrophic scoliosis secondary to NF1 who underwent 1-stage posterior correction between June 2011 and December 2013 were included. General information about patients was recorded, as were preoperative and postoperative scores from Scoliosis Research Society (SRS)-22 questionnaires. Pearson correlation analysis was used to analyze the associations among implant density, coronal Cobb angle correction rate and correction loss at last follow-up, change of sagittal curve, and apical vertebral translation. Patients were then divided into 2 groups: those with low-density and those with high-density implants. Independent-sample t-tests were used to compare demographic data, radiographic findings, and clinical outcomes before surgery and at last follow-up between the groups. RESULTS Significant correlations were found between the implant density and the coronal correction rate of the main curve (r = 0.505, p < 0.01) and the coronal correction loss at final follow-up (r = -0.379, p = 0.015). There was no significant correlation between implant density and change of sagittal profile (p = 0.662) or apical vertebral translation (p = 0.062). The SRS-22 scores improved in the appearance, activity, and mental health domains within both groups, but there was no difference between the groups in any of the SRS-22 domains at final follow-up (p > 0.05 for all). CONCLUSIONS Although no significant differences between the high- and low-density groups were found in any of the SRS-22 domains at final follow-up, higher implant density was correlated with superior coronal correction and less postoperative correction loss in patients with dystrophic NF1-associated scoliosis.

Posterior-only surgical correction of dystrophic scoliosis in 31 patients with neurofibromatosis Type 1 using the multiple anchor point method.

PubMed

Deng, Ang; Zhang, Hong-Qi; Tang, Ming-Xing; Liu, Shao-Hua; Wang, Yu-Xiang; Gao, Qi-Le

2017-01-01

OBJECTIVE The objective of this study was to evaluate the clinical efficacy of posterior-only surgical correction of dystrophic scoliosis in patients with neurofibromatosis Type 1 (NF1) using a multiple anchor point method (MAPM). METHODS From 2005 to 2014, 31 patients (mean age 13.5 years old, range 10-22 years old) suffering from dystrophic scoliosis associated with NF1 underwent posterior-only surgical correction using a MAPM. The apex of the deformity was thoracic (n = 25), thoracolumbar (n = 4), and lumbar (n = 2). The mean preoperative coronal Cobb angle was 69.1° (range 48.9°-91.4°). The mean Cobb angle on the side-bending radiograph of the convex side was 58.2° (range 40°-79.8°). The mean flexibility and apical vertebral rotation (AVR) were 15.6% (range 8.3%-28.2%) and 2.5° (range 2°-3°), respectively. The mean angle of sagittal kyphosis was 58.3° (range 34.1°-79.6°). RESULTS The mean follow-up period was 53 months (range 12-96 months). The mean postoperative coronal Cobb angle was 27.4° (range 16.3°-46.7°). Postoperatively, the mean AVR and angle of sagittal kyphosis were 1.2° (range 1°-2°) and 22.4° (range 4.2°-36.3°), respectively. All patients showed good correction of all indices postoperatively. The mean postoperative correction rate was 58.7% (range 46.3%-74.1%). At the final follow-up evaluation, the corrective loss rate of the Cobb angle was only 2.3%. Only 1 patient required revision surgery. No severe complications such as spinal cord, neural, or large vascular injury occurred during the operation. CONCLUSIONS Posterior-only surgical correction of dystrophic scoliosis in patients with NF1 using a MAPM could yield satisfactory clinical efficacy of correction and fusion.

Vision maintenance and retinal apoptosis reduction in RCS rats with Okayama University-type retinal prosthesis (OUReP™) implantation.

PubMed

Alamusi; Matsuo, Toshihiko; Hosoya, Osamu; Tsutsui, Kimiko M; Uchida, Tetsuya

2015-09-01

Photoelectric dye-coupled polyethylene film, designated Okayama University-type retinal prosthesis or OUReP™, generates light-evoked surface electric potentials and stimulates neurons. In this study, the vision was assessed by behavior tests in aged hereditary retinal dystrophic RCS rats with OUReP™, retinal apoptosis and electroretinographic responses were measured in dystrophic eyes with OUReP™. The dye-coupled films, or plain films as a control, were implanted in subretinal space of RCS rats. On behavior tests, RCS rats with dye-coupled films, implanted at the old age of 14 weeks, showed the larger number of head-turning, consistent with clockwise and anticlockwise rotation of a surrounding black-and-white-striped drum, compared with rats with plain films, under the dim (50 lux) and bright (150 lux) conditions in the observation period until the age of 22 weeks (n = 5, P < 0.05, repeated-measure ANOVA). The number of apoptotic cells in retinal sections at the site of dye-coupled film implantation was significantly smaller, compared with the other retinal sites, neighboring the film, or opposite to the film, 5 months after film implantation at the age of 6 weeks (P = 0.0021, Friedman test). The dystrophic eyes of RCS rats with dye-coupled films showed positive responses to maximal light stimulus at a significantly higher rate, compared with the eyes with no treatment (P < 0.05, Chi-square test). Electroretinograms in normal eyes of Wistar rats with dye-coupled or plain films showed significantly decreased amplitudes (n = 14, P < 0.05, repeated-measure ANOVA). In conclusions, vision was maintained in RCS rats with dye-coupled films implanted at the old age. The dystrophic eyes with dye-coupled films showed electroretinographic responses. Five-month film implantation caused no additional retinal changes.

Pulsatile Lavage of Musculoskeletal Wounds Causes Muscle Necrosis and Dystrophic Calcification in a Rat Model.

PubMed

Chiaramonti, Alexander M; Robertson, Astor D; Nguyen, Thao P; Jaffe, David E; Hanna, E Lex; Holmes, Robert; Barfield, William R; Fourney, William L; Stains, Joseph P; Pellegrini, Vincent D

2017-11-01

Adequate irrigation of open musculoskeletal injuries is considered the standard of care to decrease bacterial load and other contaminants. While the benefit of debris removal compared with the risk of further seeding by high-pressure lavage has been studied, the effects of irrigation on muscle have been infrequently reported. Our aim in the present study was to assess relative damage to muscle by pulsatile lavage compared with bulb-syringe irrigation. In an animal model of heterotopic ossification, 24 Sprague-Dawley rats underwent hindlimb blast amputation via detonation of a submerged explosive, with subsequent through-the-knee surgical amputation proximal to the zone of injury. All wounds were irrigated and underwent primary closure. In 12 of the animals, pulsatile lavage (20 psi [138 kPa]) was used as the irrigation method, and in the other 12 animals, bulb-syringe irrigation was performed. A third group of 6 rats did not undergo the blast procedure but instead underwent surgical incision into the left thigh muscle followed by pulsatile lavage. Serial radiographs of the animals were made to monitor the formation of soft-tissue radiopaque lesions until euthanasia at 6 months. Image-guided muscle biopsies were performed at 8 weeks and 6 months (at euthanasia) on representative animals from each group. Histological analysis was performed with hematoxylin and eosin, alizarin red, and von Kossa staining on interval biopsy and postmortem specimens. All animals managed with pulsatile lavage, with or without blast injury, developed soft-tissue radiopaque lesions, whereas no animal that had bulb-syringe irrigation developed these lesions (p = 0.001). Five of the 12 animals that underwent blast amputation with pulsatile lavage experienced wound complications, whereas no animal in the other 2 groups experienced wound complications (p = 0.014). Radiopaque lesions appeared approximately 10 days postoperatively, increased in density until approximately 16 weeks, then demonstrated signs of variable regression. Histological analysis of interval biopsy and postmortem specimens demonstrated tissue damage with inflammatory cells, cell death, and dystrophic calcification. Pulsatile lavage of musculoskeletal wounds can cause irreversible insult to tissue, resulting in myonecrosis and dystrophic calcification. The benefits and offsetting harm of pulsatile lavage (20 psi) should be considered before its routine use in the management of musculoskeletal wounds.

Molecular and cell-based therapies for muscle degenerations: a road under construction.

PubMed

Berardi, Emanuele; Annibali, Daniela; Cassano, Marco; Crippa, Stefania; Sampaolesi, Maurilio

2014-01-01

Despite the advances achieved in understanding the molecular biology of muscle cells in the past decades, there is still need for effective treatments of muscular degeneration caused by muscular dystrophies and for counteracting the muscle wasting caused by cachexia or sarcopenia. The corticosteroid medications currently in use for dystrophic patients merely help to control the inflammatory state and only slightly delay the progression of the disease. Unfortunately, walkers and wheel chairs are the only options for such patients to maintain independence and walking capabilities until the respiratory muscles become weak and the mechanical ventilation is needed. On the other hand, myostatin inhibition, IL-6 antagonism and synthetic ghrelin administration are examples of promising treatments in cachexia animal models. In both dystrophies and cachectic syndrome the muscular degeneration is extremely relevant and the translational therapeutic attempts to find a possible cure are well defined. In particular, molecular-based therapies are common options to be explored in order to exploit beneficial treatments for cachexia, while gene/cell therapies are mostly used in the attempt to induce a substantial improvement of the dystrophic muscular phenotype. This review focuses on the description of the use of molecular administrations and gene/stem cell therapy to treat muscular degenerations. It reviews previous trials using cell delivery protocols in mice and patients starting with the use of donor myoblasts, outlining the likely causes for their poor results and briefly focusing on satellite cell studies that raise new hope. Then it proceeds to describe recently identified stem/progenitor cells, including pluripotent stem cells and in relationship to their ability to home within a dystrophic muscle and to differentiate into skeletal muscle cells. Different known features of various stem cells are compared in this perspective, and the few available examples of their use in animal models of muscular degeneration are reported. Since non coding RNAs, including microRNAs (miRNAs), are emerging as prominent players in the regulation of stem cell fates we also provides an outline of the role of microRNAs in the control of myogenic commitment. Finally, based on our current knowledge and the rapid advance in stem cell biology, a prediction of clinical translation for cell therapy protocols combined with molecular treatments is discussed.

Genetic deletion of muscle RANK or selective inhibition of RANKL is not as effective as full-length OPG-fc in mitigating muscular dystrophy.

PubMed

Dufresne, Sébastien S; Boulanger-Piette, Antoine; Bossé, Sabrina; Argaw, Anteneh; Hamoudi, Dounia; Marcadet, Laetitia; Gamu, Daniel; Fajardo, Val A; Yagita, Hideo; Penninger, Josef M; Russell Tupling, A; Frenette, Jérôme

2018-04-24

Although there is a strong association between osteoporosis and skeletal muscle atrophy/dysfunction, the functional relevance of a particular biological pathway that regulates synchronously bone and skeletal muscle physiopathology is still elusive. Receptor-activator of nuclear factor κB (RANK), its ligand RANKL and the soluble decoy receptor osteoprotegerin (OPG) are the key regulators of osteoclast differentiation and bone remodelling. We thus hypothesized that RANK/RANKL/OPG, which is a key pathway for bone regulation, is involved in Duchenne muscular dystrophy (DMD) physiopathology. Our results show that muscle-specific RANK deletion (mdx-RANK mko ) in dystrophin deficient mdx mice improves significantly specific force [54% gain in force] of EDL muscles with no protective effect against eccentric contraction-induced muscle dysfunction. In contrast, full-length OPG-Fc injections restore the force of dystrophic EDL muscles [162% gain in force], protect against eccentric contraction-induced muscle dysfunction ex vivo and significantly improve functional performance on downhill treadmill and post-exercise physical activity. Since OPG serves a soluble receptor for RANKL and as a decoy receptor for TRAIL, mdx mice were injected with anti-RANKL and anti-TRAIL antibodies to decipher the dual function of OPG. Injections of anti-RANKL and/or anti-TRAIL increase significantly the force of dystrophic EDL muscle [45% and 17% gains in force, respectively]. In agreement, truncated OPG-Fc that contains only RANKL domains produces similar gains, in terms of force production, than anti-RANKL treatments. To corroborate that full-length OPG-Fc also acts independently of RANK/RANKL pathway, dystrophin/RANK double-deficient mice were treated with full-length OPG-Fc for 10 days. Dystrophic EDL muscles exhibited a significant gain in force relative to untreated dystrophin/RANK double-deficient mice, indicating that the effect of full-length OPG-Fc is in part independent of the RANKL/RANK interaction. The sarco/endoplasmic reticulum Ca 2+ ATPase (SERCA) activity is significantly depressed in dysfunctional and dystrophic muscles and full-length OPG-Fc treatment increased SERCA activity and SERCA-2a expression. These findings demonstrate the superiority of full-length OPG-Fc treatment relative to truncated OPG-Fc, anti-RANKL, anti-TRAIL or muscle RANK deletion in improving dystrophic muscle function, integrity and protection against eccentric contractions. In conclusion, full-length OPG-Fc represents an efficient alternative in the development of new treatments for muscular dystrophy in which a single therapeutic approach may be foreseeable to maintain both bone and skeletal muscle functions.

Dystrophic microglia in the aging human brain.

PubMed

Streit, Wolfgang J; Sammons, Nicole W; Kuhns, Amanda J; Sparks, D Larry

2004-01-15

We have studied microglial morphology in the human cerebral cortex of two nondemented subjects using high-resolution LN-3 immunohistochemistry. Several abnormalities in microglial cytoplasmic structure, including deramification, spheroid formation, gnarling, and fragmentation of processes, were identified. These changes were determined to be different from the morphological changes that occur during microglial activation and they were designated collectively as microglial dystrophy. Quantitative evaluation of dystrophic changes in microglia revealed that these were much more prevalent in the older subject (68-year-old) than in the younger one (38-year-old). Thus, we conclude that microglial dystrophy is a sign of microglial cell senescence. We hypothesize that microglial senescence could be important for understanding age-related declines in cognitive function. Copyright 2003 Wiley-Liss, Inc.

Changes of the vasculature and innervation in the anterior segment of the RCS rat eye.

PubMed

May, Christian Albrecht

2011-12-01

Investigating the anterior eye segment vasculature and innervation of dystrophic RCS rats, two major unique findings were observed: in the iris, young adult animals with retinal dystrophy showed an increase in substance P nerve fibres and a dilation of arterioles and capillaries. This finding continued during ageing. In the pars plana region, the surface covered by venules decreased continuously with age. In older animals, this decrease was parallelled by a local decrease of sympathetic TH-positive nerve fibres supplying these venules. For both conditions, no comparable data exists so far in the literature. They might point to a unique situation in the anterior eye segment of the dystrophic RCS rat. Copyright © 2011 Elsevier Ltd. All rights reserved.

Whitening of endodontically untreated calcified anterior teeth.

PubMed

Pedorella, C A; Meyer, R D; Woollard, G W

2000-01-01

Definitive treatment for whitening endodontically untreated anterior teeth with dystrophic calcification is provided by removing the coronal sclerotic dentin and utilizing internal and external bleaching as necessary.

Pharmacological Inhibition of PKCθ Counteracts Muscle Disease in a Mouse Model of Duchenne Muscular Dystrophy.

PubMed

Marrocco, V; Fiore, P; Benedetti, A; Pisu, S; Rizzuto, E; Musarò, A; Madaro, L; Lozanoska-Ochser, B; Bouché, M

2017-02-01

Inflammation plays a considerable role in the progression of Duchenne Muscular Dystrophy (DMD), a severe muscle disease caused by a mutation in the dystrophin gene. We previously showed that genetic ablation of Protein Kinase C θ (PKCθ) in mdx, the mouse model of DMD, improves muscle healing and regeneration, preventing massive inflammation. To establish whether pharmacological targeting of PKCθ in DMD can be proposed as a therapeutic option, in this study we treated young mdx mice with the PKCθ inhibitor Compound 20 (C20). We show that C20 treatment led to a significant reduction in muscle damage associated with reduced immune cells infiltration, reduced inflammatory pathways activation, and maintained muscle regeneration. Importantly, C20 treatment is efficient in recovering muscle performance in mdx mice, by preserving muscle integrity. Together, these results provide proof of principle that pharmacological inhibition of PKCθ in DMD can be considered an attractive strategy to modulate immune response and prevent the progression of the disease. Duchenne muscular dystrophy (DMD) is a severe muscle disease affecting 1:3500 male births. DMD is caused by a mutation in dystrophin gene, coding for a protein required for skeletal and cardiac muscle integrity. Lack of a functional dystrophin is primarily responsible for the muscle eccentric contraction-induced muscle damage, observed in dystrophic muscle. However, inflammation plays a considerable role in the progression of DMD. Glucocorticoids, which have anti-inflammatory properties, are being used to treat DMD with some success; however, long term treatment with these drugs induces muscle atrophy and wasting, outweighing their benefit. The identification of specific targets for anti-inflammatory therapies is one of the ongoing therapeutic options. Although blunting inflammation would not be a "cure" for the disease, the emerging clue is that multiple strategies, addressing different aspects of the pathology, which may eventually converge, may be successful. In this context, we previously showed that genetic ablation of Protein Kinase C θ (PKCθ), an enzyme known to be involved in immune response, in mdx, the mouse model of DMD, improves muscle healing and regeneration, preventing massive inflammation. To establish whether pharmacological targeting of PKCθ in DMD can be proposed as a therapeutic option, in this study we treated young mdx mice with the PKCθ inhibitor Compound 20 (C20). We show that C20 treatment led to a significant reduction in muscle damage associated with reduced immune cells infiltration, reduced inflammatory pathways activation, and maintained muscle regeneration. Importantly, C20 treatment is efficient in recovering muscle performance in mdx mice, by preserving muscle integrity. Together, these results provide proof of principle that pharmacological inhibition of PKCθ in DMD can be considered an attractive strategy to modulate immune response and prevent the progression of the disease. Copyright © 2017 3-V Biosciences. Published by Elsevier B.V. All rights reserved.

Differentiation of original and regenerated skeletal muscle fibres in mdx dystrophic muscles.

PubMed

Earnshaw, John C; Kyprianou, Phillip; Krishan, Kewal; Dhoot, Gurtej K

2002-07-01

The differentiation of both original muscle fibres and the regenerated muscle fibres following necrosis in mdx muscles was investigated using immunoblotting and immunocytochemical procedures. Before the onset of necrosis, postnatal skeletal muscles in mdx mouse differentiated well with only a slight delay in differentiation indicated by the level of developmental isoforms of troponin T. Prior to the onset of apparent myopathic change, both fast and slow skeletal muscle fibre types in mdx leg muscles also differentiated well when investigated by analysis of specific myosin heavy chain expression pattern. While the original muscle fibres in mdx leg muscles developed well, the differentiation of regenerated myotubes into both slow and distinct fast muscle fibre types, however, was markedly delayed or inhibited as indicated by several clusters of homogeneously staining fibres even at 14 weeks of age. The number of slow myosin heavy chain-positive myotubes amongst the regenerated muscle clusters was quite small even in soleus. This study thus established that while muscle fibres initially develop normally with only a slight delay in the differentiation process, the differentiation of regenerated myotubes in mdx muscles is markedly compromised and consequently delayed.

The effects of a skeletal muscle titin mutation on walking in mice.

PubMed

Pace, Cinnamon M; Mortimer, Sarah; Monroy, Jenna A; Nishikawa, Kiisa C

2017-01-01

Titin contributes to sarcomere assembly, muscle signaling, and mechanical properties of muscle. The mdm mouse exhibits a small deletion in the titin gene resulting in dystrophic mutants and phenotypically normal heterozygotes. We examined the effects of this mutation on locomotion to assess how, and if, changes to muscle phenotype explain observed locomotor differences. Mutant mice are much smaller in size than their siblings and gait abnormalities may be driven by differences in limb proportions and/or by changes to muscle phenotype caused by the titin mutation. We quantified differences in walking gait among mdm genotypes and also determined whether genotypes vary in limb morphometrics. Mice were filmed walking, and kinematic and morphological variables were measured. Mutant mice had a smaller range of motion at the ankle, shorter stride lengths, and shorter stance duration, but walked at the same relative speeds as the other genotypes. Although phenotypically similar to wildtype mice, heterozygous mice frequently exhibited intermediate gait mechanics. Morphological differences among genotypes in hindlimb proportions were small and do not explain the locomotor differences. We suggest that differences in locomotion among mdm genotypes are due to changes in muscle phenotype caused by the titin mutation.

Neuronal and Peripheral Pentraxins Modify Glutamate Release and may Interact in Blood-Brain Barrier Failure.

PubMed

Cummings, Damian M; Benway, Tiffanie A; Ho, Hinze; Tedoldi, Angelo; Fernandes Freitas, Monica M; Shahab, Lion; Murray, Christina E; Richard-Loendt, Angela; Brandner, Sebastian; Lashley, Tammaryn; Salih, Dervis A; Edwards, Frances A

2017-06-01

Neuronal pentraxin 1 (NPTX1) has been implicated in Alzheimer's disease, being present in and around dystrophic neurons in plaques, affecting glutamatergic transmission postsynaptically and mediating effects of amyloidβ. Here, we confirm the presence of NPTX1 around plaques in postmortem Alzheimer's disease brain and report that acutely applied human NPTX1 increases paired-pulse ratio at mouse CA3-CA1 hippocampal synapses, indicating a decrease in glutamate release. In contrast, chronic exposure to NPTX1, NPTX2, or NPTX receptor decreases paired-pulse ratio, mimicking some of the earliest changes in mice expressing familial Alzheimer's disease genes. The peripheral pentraxin, serum amyloid P component (SAP), causes similar synaptic effects to NPTX1. The presence of SAP on amyloid plaques in Alzheimer's disease confirms that it can enter the brain. We show that SAP and neuronal pentraxins can interact and that SAP can enter the brain if the blood-brain barrier is compromised, suggesting that peripheral pentraxins could affect central synaptic transmission via this interaction, especially in the event of blood-brain barrier breakdown. © The Author 2017. Published by Oxford University Press.

Acute inhibition of myostatin-family proteins preserves skeletal muscle in mouse models of cancer cachexia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benny Klimek, Margaret E.; Aydogdu, Tufan; Link, Majik J.

2010-01-15

Cachexia, progressive loss of fat and muscle mass despite adequate nutrition, is a devastating complication of cancer associated with poor quality of life and increased mortality. Myostatin is a potent tonic muscle growth inhibitor. We tested how myostatin inhibition might influence cancer cachexia using genetic and pharmacological approaches. First, hypermuscular myostatin null mice were injected with Lewis lung carcinoma or B16F10 melanoma cells. Myostatin null mice were more sensitive to tumor-induced cachexia, losing more absolute mass and proportionately more muscle mass than wild-type mice. Because myostatin null mice lack expression from development, however, we also sought to manipulate myostatin acutely.more » The histone deacetylase inhibitor Trichostatin A has been shown to increase muscle mass in normal and dystrophic mice by inducing the myostatin inhibitor, follistatin. Although Trichostatin A administration induced muscle growth in normal mice, it failed to preserve muscle in colon-26 cancer cachexia. Finally we sought to inhibit myostatin and related ligands by administration of the Activin receptor extracellular domain/Fc fusion protein, ACVR2B-Fc. Systemic administration of ACVR2B-Fc potently inhibited muscle wasting and protected adipose stores in both colon-26 and Lewis lung carcinoma cachexia, without affecting tumor growth. Enhanced cachexia in myostatin knockouts indicates that host-derived myostatin is not the sole mediator of muscle wasting in cancer. More importantly, skeletal muscle preservation with ACVR2B-Fc establishes that targeting myostatin-family ligands using ACVR2B-Fc or related molecules is an important and potent therapeutic avenue in cancer cachexia.« less

Concurrent Label-Free Mass Spectrometric Analysis of Dystrophin Isoform Dp427 and the Myofibrosis Marker Collagen in Crude Extracts from mdx-4cv Skeletal Muscles

PubMed Central

Murphy, Sandra; Zweyer, Margit; Mundegar, Rustam R.; Henry, Michael; Meleady, Paula; Swandulla, Dieter; Ohlendieck, Kay

2015-01-01

The full-length dystrophin protein isoform of 427 kDa (Dp427), the absence of which represents the principal abnormality in X-linked muscular dystrophy, is difficult to identify and characterize by routine proteomic screening approaches of crude tissue extracts. This is probably related to its large molecular size, its close association with the sarcolemmal membrane, and its existence within a heterogeneous glycoprotein complex. Here, we used a careful extraction procedure to isolate the total protein repertoire from normal versus dystrophic mdx-4cv skeletal muscles, in conjunction with label-free mass spectrometry, and successfully identified Dp427 by proteomic means. In contrast to a considerable number of previous comparative studies of the total skeletal muscle proteome, using whole tissue proteomics we show here for the first time that the reduced expression of this membrane cytoskeletal protein is the most significant alteration in dystrophinopathy. This agrees with the pathobiochemical concept that the almost complete absence of dystrophin is the main defect in Duchenne muscular dystrophy and that the mdx-4cv mouse model of dystrophinopathy exhibits only very few revertant fibers. Significant increases in collagens and associated fibrotic marker proteins, such as fibronectin, biglycan, asporin, decorin, prolargin, mimecan, and lumican were identified in dystrophin-deficient muscles. The up-regulation of collagen in mdx-4cv muscles was confirmed by immunofluorescence microscopy and immunoblotting. Thus, this is the first mass spectrometric study of crude tissue extracts that puts the proteomic identification of dystrophin in its proper pathophysiological context. PMID:28248273

Acute inhibition of myostatin-family proteins preserves skeletal muscle in mouse models of cancer cachexia.

PubMed

Benny Klimek, Margaret E; Aydogdu, Tufan; Link, Majik J; Pons, Marianne; Koniaris, Leonidas G; Zimmers, Teresa A

2010-01-15

Cachexia, progressive loss of fat and muscle mass despite adequate nutrition, is a devastating complication of cancer associated with poor quality of life and increased mortality. Myostatin is a potent tonic muscle growth inhibitor. We tested how myostatin inhibition might influence cancer cachexia using genetic and pharmacological approaches. First, hypermuscular myostatin null mice were injected with Lewis lung carcinoma or B16F10 melanoma cells. Myostatin null mice were more sensitive to tumor-induced cachexia, losing more absolute mass and proportionately more muscle mass than wild-type mice. Because myostatin null mice lack expression from development, however, we also sought to manipulate myostatin acutely. The histone deacetylase inhibitor Trichostatin A has been shown to increase muscle mass in normal and dystrophic mice by inducing the myostatin inhibitor, follistatin. Although Trichostatin A administration induced muscle growth in normal mice, it failed to preserve muscle in colon-26 cancer cachexia. Finally we sought to inhibit myostatin and related ligands by administration of the Activin receptor extracellular domain/Fc fusion protein, ACVR2B-Fc. Systemic administration of ACVR2B-Fc potently inhibited muscle wasting and protected adipose stores in both colon-26 and Lewis lung carcinoma cachexia, without affecting tumor growth. Enhanced cachexia in myostatin knockouts indicates that host-derived myostatin is not the sole mediator of muscle wasting in cancer. More importantly, skeletal muscle preservation with ACVR2B-Fc establishes that targeting myostatin-family ligands using ACVR2B-Fc or related molecules is an important and potent therapeutic avenue in cancer cachexia. Copyright 2009 Elsevier Inc. All rights reserved.

Treatment with rGDF11 does not improve the dystrophic muscle pathology of mdx mice.

PubMed

Rinaldi, Fabrizio; Zhang, Yu; Mondragon-Gonzalez, Ricardo; Harvey, Jeffrey; Perlingeiro, Rita C R

2016-01-01

Duchenne muscular dystrophy (DMD) is an inherited lethal muscle wasting disease characterized by cycles of degeneration and regeneration, with no effective therapy. Growth differentiation factor 11 (GDF11), a member of the TGF-β superfamily and myostatin homologous, has been reported to have the capacity to reverse age-related skeletal muscle loss. These initial findings led us to investigate the ability of GDF11 to promote regeneration in the context of muscular dystrophy and determine whether it could be a candidate to slow down or reverse the disease progression in DMD. Here, we delivered recombinant GDF11 (rGDF11) to dystrophin-deficient mice using the intra-peritoneal route for 30 days and evaluated histology and function in both steady-state and cardiotoxin-injured muscles. Our data confirmed that treatment with rGDF11 resulted in elevated levels of this factor in the circulation. However, this had no effect on muscle contractility nor on muscle histology. Moreover, no difference was found in the number of regenerating myofibers displaying centrally located nuclei. On the other hand, we did observe increased collagen content, which denotes fibrosis, in the muscles of rGDF11-treated dystrophic mice. Taken together, our findings indicate no beneficial effect of treating dystrophic mice with rGDF11 and raise caution to a potential harmful effect, as shown by the pro-fibrotic outcome.

piggyBac transposons expressing full-length human dystrophin enable genetic correction of dystrophic mesoangioblasts

PubMed Central

Loperfido, Mariana; Jarmin, Susan; Dastidar, Sumitava; Di Matteo, Mario; Perini, Ilaria; Moore, Marc; Nair, Nisha; Samara-Kuko, Ermira; Athanasopoulos, Takis; Tedesco, Francesco Saverio; Dickson, George; Sampaolesi, Maurilio; VandenDriessche, Thierry; Chuah, Marinee K.

2016-01-01

Duchenne muscular dystrophy (DMD) is a genetic neuromuscular disorder caused by the absence of dystrophin. We developed a novel gene therapy approach based on the use of the piggyBac (PB) transposon system to deliver the coding DNA sequence (CDS) of either full-length human dystrophin (DYS: 11.1 kb) or truncated microdystrophins (MD1: 3.6 kb; MD2: 4 kb). PB transposons encoding microdystrophins were transfected in C2C12 myoblasts, yielding 65±2% MD1 and 66±2% MD2 expression in differentiated multinucleated myotubes. A hyperactive PB (hyPB) transposase was then deployed to enable transposition of the large-size PB transposon (17 kb) encoding the full-length DYS and green fluorescence protein (GFP). Stable GFP expression attaining 78±3% could be achieved in the C2C12 myoblasts that had undergone transposition. Western blot analysis demonstrated expression of the full-length human DYS protein in myotubes. Subsequently, dystrophic mesoangioblasts from a Golden Retriever muscular dystrophy dog were transfected with the large-size PB transposon resulting in 50±5% GFP-expressing cells after stable transposition. This was consistent with correction of the differentiated dystrophic mesoangioblasts following expression of full-length human DYS. These results pave the way toward a novel non-viral gene therapy approach for DMD using PB transposons underscoring their potential to deliver large therapeutic genes. PMID:26682797

Dystrophic Serotonergic Axons in Neurodegenerative Diseases

PubMed Central

Azmitia, Efrain C.; Nixon, Ralph

2012-01-01

Neurodegenerative diseases such as Parkinson's disease (PD), frontal lobe dementia (FLD) and Diffuse Lewy-Body dementia (DLBD) have diverse neuropathologic features. Here we report that serotonin fibers are dystrophic in the brains of individuals with these three diseases. In neuropathologically normal (control) brains (n=3), serotonin axons immunoreactive (IR) with antibodies against the serotonin transporter (5-HTT) protein were widely distributed in cortex (entorhinal and dorsolateral prefrontal), hippocampus and rostral brainstem. 5-HTT-IR fibers of passage appeared thick, smooth, and un-branched in medial forebrain bundle, medial lemniscus and cortex white matter. The terminal branches were fine, highly branched and varicose in substantia nigra, hippocampus and cortical gray matter. In the diseased brains, however, 5-HTT-IR fibers in the forebrain were reduced in number and were frequently bulbous, splayed, tightly clustered and enlarged. Morphometric analysis revealed significant differences in the size distribution of the 5-HTT-IR profiles in dorsolateral prefrontal area between neurodegenerative diseases and controls. Our observations provide direct morphologic evidence for degeneration of human serotonergic axons in the brains of patients with neurodegenerative diseases despite the limited size (n=3 slices for each region (3) from each brain (4), total slices was n=36) and lack of extensive clinical characterization of the analyzed cohort. This is the first report of dystrophic 5-HTT-IR axons in postmortem human tissue PMID:18502405

The international dystrophic epidermolysis bullosa patient registry: an online database of dystrophic epidermolysis bullosa patients and their COL7A1 mutations.

PubMed

van den Akker, Peter C; Jonkman, Marcel F; Rengaw, Trebor; Bruckner-Tuderman, Leena; Has, Cristina; Bauer, Johann W; Klausegger, Alfred; Zambruno, Giovanna; Castiglia, Daniele; Mellerio, Jemima E; McGrath, John A; van Essen, Anthonie J; Hofstra, Robert M W; Swertz, Morris A

2011-10-01

Dystrophic epidermolysis bullosa (DEB) is a heritable blistering disorder that can be inherited autosomal dominantly (DDEB) or recessively (RDEB) and covers a group of several distinctive phenotypes. A large number of unique COL7A1 mutations have been shown to underlie DEB. Although general genotype-phenotype correlation rules have emerged, many exceptions to these rules exist, compromising disease diagnosing and genetic counseling. We therefore constructed the International DEB Patient Registry (http://www.deb-central.org), aimed at worldwide collection and sharing of phenotypic and genotypic information on DEB. As of May 2011, this MOLGENIS-based registry contains detailed information on 508 published and 71 unpublished patients and their 388 unique COL7A1 mutations, and includes all combinations of mutations. The current registry RDEB versus DDEB ratio of 4:1, if compared to prevalence figures, suggests underreporting of DDEB in the literature. Thirty-eight percent of mutations stored introduce a premature termination codon (PTC) and 43% an amino acid change. Submission wizards allow users to quickly and easily share novel information. This registry will be of great help in disease diagnosing and genetic counseling and will lead to novel insights, especially in the rare phenotypes of which there is often lack of understanding. Altogether, this registry will greatly benefit the DEB patients. © 2011 Wiley-Liss, Inc.

Mesodermal iPSC–derived progenitor cells functionally regenerate cardiac and skeletal muscle

PubMed Central

Quattrocelli, Mattia; Swinnen, Melissa; Giacomazzi, Giorgia; Camps, Jordi; Barthélemy, Ines; Ceccarelli, Gabriele; Caluwé, Ellen; Grosemans, Hanne; Thorrez, Lieven; Pelizzo, Gloria; Muijtjens, Manja; Verfaillie, Catherine M.; Blot, Stephane; Janssens, Stefan; Sampaolesi, Maurilio

2015-01-01

Conditions such as muscular dystrophies (MDs) that affect both cardiac and skeletal muscles would benefit from therapeutic strategies that enable regeneration of both of these striated muscle types. Protocols have been developed to promote induced pluripotent stem cells (iPSCs) to differentiate toward cardiac or skeletal muscle; however, there are currently no strategies to simultaneously target both muscle types. Tissues exhibit specific epigenetic alterations; therefore, source-related lineage biases have the potential to improve iPSC-driven multilineage differentiation. Here, we determined that differential myogenic propensity influences the commitment of isogenic iPSCs and a specifically isolated pool of mesodermal iPSC-derived progenitors (MiPs) toward the striated muscle lineages. Differential myogenic propensity did not influence pluripotency, but did selectively enhance chimerism of MiP-derived tissue in both fetal and adult skeletal muscle. When injected into dystrophic mice, MiPs engrafted and repaired both skeletal and cardiac muscle, reducing functional defects. Similarly, engraftment into dystrophic mice of canine MiPs from dystrophic dogs that had undergone TALEN-mediated correction of the MD-associated mutation also resulted in functional striatal muscle regeneration. Moreover, human MiPs exhibited the same capacity for the dual differentiation observed in murine and canine MiPs. The findings of this study suggest that MiPs should be further explored for combined therapy of cardiac and skeletal muscles. PMID:26571398

Muscular dystrophy in a dish: engineered human skeletal muscle mimetics for disease modeling and drug discovery

PubMed Central

Smith, Alec S.T.; Davis, Jennifer; Lee, Gabsang; Mack, David L.

2016-01-01

Engineered in vitro models using human cells, particularly patient-derived induced pluripotent stem cells (iPSCs), offer a potential solution to issues associated with the use of animals for studying disease pathology and drug efficacy. Given the prevalence of muscle diseases in human populations, an engineered tissue model of human skeletal muscle could provide a biologically accurate platform to study basic muscle physiology, disease progression, and drug efficacy and/or toxicity. Such platforms could be used as phenotypic drug screens to identify compounds capable of alleviating or reversing congenital myopathies, such as Duchene muscular dystrophy (DMD). Here, we review current skeletal muscle modeling technologies with a specific focus on efforts to generate biomimetic systems for investigating the pathophysiology of dystrophic muscle. PMID:27109386

Low-intensity training provokes adaptive extracellular matrix turnover of a muscular dystrophy model

PubMed Central

Gaiad, Thaís P.; Oliveira, Murilo X.; Lobo, Adalfredo R.; Libório, Lívia R.; Pinto, Priscilla A.F.; Fernandes, Danielle C.; Santos, Ana Paula; Ambrósio, Carlos Eduardo; Machado, Alex Sander D.

2017-01-01

Recommendations of therapeutic exercise in Duchenne muscular dystrophy are still controversial. The hypothesis that a low-intensity training (LIT) protocol leads to muscle adaptations on mdx mice model was tested. Dystrophic male mice with 8 weeks old were separated in exercised (mdxE, n= 8) and sedentary (mdxC, n= 8) groups. Wild-type mice were used as control (WT, n= 8) group. Exercised group underwent a LIT protocol (9 m/min, 30 min, 3 days/wk, 60 days) on a horizontal treadmill. At day 60 all animals were analyzed regarding parameters of markers of muscle lesion and extracellular matrix turnover of muscle tissue by collagens fibers on tibial anterior muscle. Histomorphometry attested that centrally located nuclei fibers and the coefficient of variance of minimal Feret’s diameter was similar in mdxE and mdxC groups (P= 1.000) and both groups presented higher mean values than WT group (P< 0.001). Fraction area of collagen fibers of mdxE group was lower than mdxC group (P= 0,027) and similar to WT group (P= 0,751). Intramuscular area of Col3 of the mdxE group was higher than mdxC and WT groups (P<0.001). Intramuscular area of Col1 on the mdxE group was similar to the mdxC group (P= 1.000) and both groups were higher than WT group (P< 0.001). LIT protocol had not influenced muscle injuries resulting from the dystrophin-deficiency membrane fragility. Although, LIT had provoked adaptations on extracellular matrix bringing higher elastic feature to dystrophic muscle tissue. PMID:29326902

miR-708-5p and miR-34c-5p are involved in nNOS regulation in dystrophic context.

PubMed

Guilbaud, Marine; Gentil, Christel; Peccate, Cécile; Gargaun, Elena; Holtzmann, Isabelle; Gruszczynski, Carole; Falcone, Sestina; Mamchaoui, Kamel; Ben Yaou, Rabah; Leturcq, France; Jeanson-Leh, Laurence; Piétri-Rouxel, France

2018-04-27

Duchenne (DMD) and Becker (BMD) muscular dystrophies are caused by mutations in the DMD gene coding for dystrophin, a protein being part of a large sarcolemmal protein scaffold that includes the neuronal nitric oxide synthase (nNOS). The nNOS was shown to play critical roles in a variety of muscle functions and alterations of its expression and location in dystrophic muscle fiber leads to an increase of the muscle fatigability. We previously revealed a decrease of nNOS expression in BMD patients all presenting a deletion of exons 45 to 55 in the DMD gene (BMDd45-55), impacting the nNOS binding site of dystrophin. Since several studies showed deregulation of microRNAs (miRNAs) in dystrophinopathies, we focused on miRNAs that could target nNOS in dystrophic context. By a screening of 617 miRNAs in BMDd45-55 muscular biopsies using TLDA and an in silico study to determine which one could target nNOS, we selected four miRNAs. In order to select those that targeted a sequence of 3'UTR of NOS1, we performed luciferase gene reporter assay in HEK393T cells. Finally, expression of candidate miRNAs was modulated in control and DMD human myoblasts (DMDd45-52) to study their ability to target nNOS. TLDA assay and the in silico study allowed us to select four miRNAs overexpressed in muscle biopsies of BMDd45-55 compared to controls. Among them, only the overexpression of miR-31, miR-708, and miR-34c led to a decrease of luciferase activity in an NOS1-3'UTR-luciferase assay, confirming their interaction with the NOS1-3'UTR. The effect of these three miRNAs was investigated on control and DMDd45-52 myoblasts. First, we showed a decrease of nNOS expression when miR-708 or miR-34c were overexpressed in control myoblasts. We then confirmed that DMDd45-52 cells displayed an endogenous increased of miR-31, miR-708, and miR-34c and a decreased of nNOS expression, the same characteristics observed in BMDd45-55 biopsies. In DMDd45-52 cells, we demonstrated that the inhibition of miR-708 and miR-34c increased nNOS expression, confirming that both miRNAs can modulate nNOS expression in human myoblasts. These results strongly suggest that miR-708 and miR-34c, overexpressed in dystrophic context, are new actors involved in the regulation of nNOS expression in dystrophic muscle.

Myostatin genetic inactivation inhibits myogenesis by muscle-derived stem cells in vitro but not when implanted in the mdx mouse muscle

PubMed Central

2013-01-01

Introduction Stimulating the commitment of implanted dystrophin+ muscle-derived stem cells (MDSCs) into myogenic, as opposed to lipofibrogenic lineages, is a promising therapeutic strategy for Duchenne muscular dystrophy (DMD). Methods To examine whether counteracting myostatin, a negative regulator of muscle mass and a pro-lipofibrotic factor, would help this process, we compared the in vitro myogenic and fibrogenic capacity of MDSCs from wild-type (WT) and myostatin knockout (Mst KO) mice under various modulators, the expression of key stem cell and myogenic genes, and the capacity of these MDSCs to repair the injured gastrocnemius in aged dystrophic mdx mice with exacerbated lipofibrosis. Results Surprisingly, the potent in vitro myotube formation by WT MDSCs was refractory to modulators of myostatin expression or activity, and the Mst KO MDSCs failed to form myotubes under various conditions, despite both MDSC expressing Oct 4 and various stem cell genes and differentiating into nonmyogenic lineages. The genetic inactivation of myostatin in MDSCs was associated with silencing of critical genes for early myogenesis (Actc1, Acta1, and MyoD). WT MDSCs implanted into the injured gastrocnemius of aged mdx mice significantly improved myofiber repair and reduced fat deposition and, to a lesser extent, fibrosis. In contrast to their in vitro behavior, Mst KO MDSCs in vivo also significantly improved myofiber repair, but had few effects on lipofibrotic degeneration. Conclusions Although WT MDSCs are very myogenic in culture and stimulate muscle repair after injury in the aged mdx mouse, myostatin genetic inactivation blocks myotube formation in vitro, but the myogenic capacity is recovered in vivo under the influence of the myostatin+ host-tissue environment, presumably by reactivation of key genes originally silenced in the Mst KO MDSCs. PMID:23295128

Nonsense variant in COL7A1 causes recessive dystrophic epidermolysis bullosa in Central Asian Shepherd dogs.

PubMed

Niskanen, Julia; Dillard, Kati; Arumilli, Meharji; Salmela, Elina; Anttila, Marjukka; Lohi, Hannes; Hytönen, Marjo K

2017-01-01

A rare hereditary mechanobullous disorder called epidermolysis bullosa (EB) causes blistering in the skin and the mucosal membranes. To date, nineteen EB-related genes have been discovered in human and other species. We describe here a novel EB variant in dogs. Two newborn littermates of Central Asian Shepherd dogs with severe signs of skin blistering were brought to a veterinary clinic and euthanized due to poor prognosis. In post-mortem examination, the puppies were shown to have findings in the skin and the mucosal membranes characteristic of EB. A whole-genome sequencing of one of the affected puppies was performed to identify the genetic cause. The resequencing data were filtered under a recessive model against variants from 31 other dog genomes, revealing a homozygous case-specific nonsense variant in one of the known EB-causing genes, COL7A1 (c.4579C>T, p.R1527*). The variant results in a premature stop codon and likely absence of the functional protein in the basement membrane of the skin in the affected dogs. This was confirmed by immunohistochemistry using a COL7A1 antibody. Additional screening of the variant indicated full penetrance and breed specificity at ~28% carrier frequency. In summary, this study reveals a novel COL7A1 variant causing recessive dystrophic EB and provides a genetic test for the eradication of the disease from the breed.

A novel triple repeat mutant tau transgenic model that mimics aspects of pick's disease and fronto-temporal tauopathies.

PubMed

Rockenstein, Edward; Overk, Cassia R; Ubhi, Kiren; Mante, Michael; Patrick, Christina; Adame, Anthony; Bisquert, Alejandro; Trejo-Morales, Margarita; Spencer, Brian; Masliah, Eliezer

2015-01-01

Tauopathies are a group of disorders leading to cognitive and behavioral impairment in the aging population. While four-repeat (4R) Tau is more abundant in corticobasal degeneration, progressive supranuclear palsy, and Alzheimer's disease, three-repeat (3R) Tau is the most abundant splice, in Pick's disease. A number of transgenic models expressing wild-type and mutant forms of the 4R Tau have been developed. However, few models of three-repeat Tau are available. A transgenic mouse model expressing three-repeat Tau was developed bearing the mutations associated with familial forms of Pick's disease (L266V and G272V mutations). Two lines expressing high (Line 13) and low (Line 2) levels of the three-repeat mutant Tau were analyzed. By Western blot, using antibodies specific to three-repeat Tau, Line 13 expressed 5-times more Tau than Line 2. The Tau expressed by these mice was most abundant in the frontal-temporal cortex and limbic system and was phosphorylated at residues detected by the PHF-1, AT8, CP9 and CP13 antibodies. The higher-expressing mice displayed hyperactivity, memory deficits in the water maze and alterations in the round beam. The behavioral deficits started at 6-8 months of age and were associated with a progressive increase in the accumulation of 3R Tau. By immunocytochemistry, mice from Line 13 displayed extensive accumulation of 3R Tau in neuronal cells bodies in the pyramidal neurons of the neocortex, CA1-3 regions, and dentate gyrus of the hippocampus. Aggregates in the granular cells had a globus appearance and mimic Pick's-like inclusions. There were abundant dystrophic neurites, astrogliosis and synapto-dendritic damage in the neocortex and hippocampus of the higher expresser line. The hippocampal lesions were moderately argyrophilic and Thioflavin-S negative. By electron microscopy, discrete straight filament aggregates were detected in some neurons in the hippocampus. This model holds promise for better understanding the natural history and progression of 3R tauopathies and their relationship with mitochondrial alterations and might be suitable for therapeutical testing.

Photopic ERG negative response from amacrine cell signaling in RCS rat retinal degeneration.

PubMed

Machida, Shigeki; Raz-Prag, Dorit; Fariss, Robert N; Sieving, Paul A; Bush, Ronald A

2008-01-01

The authors investigated photopic electroretinographic changes during degeneration in the Royal College of Surgeons (RCS) and transgenic P23H rhodopsin rat models, including the cellular origins of a large corneal-negative component that persists in the RCS rat. Photopic and scotopic electroretinograms (ERGs) were recorded from dystrophic RCS (RCS-p(+)/Lav) rats (4-18 weeks old) and transgenic rhodopsin Pro23His line 1 (P23H) rats (4-30 weeks old). Age-matched congenic (RCS-rdy(+)p(+)/Lav) and Sprague-Dawley rats were used as controls. N-methyl-DL-aspartic acid (NMA), dopamine, and gamma-aminobutyric acid (GABA) were injected intravitreally, and optic nerve sectioning (ONS) was performed to suppress or remove inner retinal neuron activity. Retinal morphology for cone cell counts and immunohistochemistry for quantification of Kir4.1 channels were performed at various stages of degeneration. As degeneration progressed, the photopic ERG of RCS dystrophic rats was distinctly different from that of P23H rats, primarily because of the growth of a corneal-negative response (RCS-NPR) after the b-wave in RCS rats. This response had a peak time similar to the photopic negative response (PhNR) in controls but with a more gradual recovery phase, and it was not affected by ONS. The PhNR in P23H rats declined linearly with the b-wave. NMA and GABA eliminated the RCS-NPR and uncovered a larger b-wave in RCS rats at late stages of degeneration, but NMA had little effect on the ERG in P23H rats. The NMA-sensitive negative response in RCS rats declined with age more slowly than did the NMA-isolated b-wave. The density of Kir4.1 channels at the endfeet of Müller cells and in the proximal retina increased significantly between 6 to 10 weeks and 14 weeks of age in the RCS rat retina but not in the P23H rat retina. The photopic ERG of the dystrophic RCS rat retina becomes increasingly electronegative because of an aberrant negative response, originating from amacrine cell activity, which declines more slowly than the b-wave with degeneration. The absence of this response in the P23H rat indicates that the inner retinal cone pathway pathology is different in the two models. A relative increase in Kir4.1 channels on Müller cells of RCS retina may contribute to the enhanced negative ERG response in the RCS rat.

Genetics Home Reference: dystrophic epidermolysis bullosa

MedlinePlus

... protein that is used to assemble type VII collagen. Collagens are molecules that give structure and strength to ... tendons, and ligaments, throughout the body. Type VII collagen plays an important role in strengthening and stabilizing ...

Seasonal variation of cadmium toxicity toward the alga Selenastrum capricornutum Printz in two lakes with different humus content

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laegreid, M.; Alstad, J.; Klaveness, D.

The alga Selenastrum capricornutum Printz is used to investigate the potential of natural lake water to reduce cadmium toxicity. The two lakes involved differ in trophic status and in concentration and composition of dissolved organic matter, one being a typical dystrophic bog lake, the other a less humus influenced, eutrophic lake. In the dystrophic lake, the toxic effect is determined mainly by the free cadmium activity. In the eutrophic, less humus influenced lake, however, the toxic effect shows considerable seasonal variations with a toxicity far exceeding what would be expected according to the estimated free ion activity during summer. Itmore » is hypothesized that qualitative changes in the composition of the dissolved organic matter during the production period are responsible for this effect.« less

Phagocytic clearance of presynaptic dystrophies by reactive astrocytes in Alzheimer's disease

PubMed Central

Gomez‐Arboledas, Angela; Davila, Jose C.; Sanchez‐Mejias, Elisabeth; Navarro, Victoria; Nuñez‐Diaz, Cristina; Sanchez‐Varo, Raquel; Sanchez‐Mico, Maria Virtudes; Trujillo‐Estrada, Laura; Fernandez‐Valenzuela, Juan Jose; Vizuete, Marisa; Comella, Joan X.; Galea, Elena

2017-01-01

Abstract Reactive astrogliosis, a complex process characterized by cell hypertrophy and upregulation of components of intermediate filaments, is a common feature in brains of Alzheimer's patients. Reactive astrocytes are found in close association with neuritic plaques; however, the precise role of these glial cells in disease pathogenesis is unknown. In this study, using immunohistochemical techniques and light and electron microscopy, we report that plaque‐associated reactive astrocytes enwrap, engulf and may digest presynaptic dystrophies in the hippocampus of amyloid precursor protein/presenilin‐1 (APP/PS1) mice. Microglia, the brain phagocytic population, was apparently not engaged in this clearance. Phagocytic reactive astrocytes were present in 35% and 67% of amyloid plaques at 6 and 12 months of age, respectively. The proportion of engulfed dystrophic neurites was low, around 7% of total dystrophies around plaques at both ages. This fact, along with the accumulation of dystrophic neurites during disease course, suggests that the efficiency of the astrocyte phagocytic process might be limited or impaired. Reactive astrocytes surrounding and engulfing dystrophic neurites were also detected in the hippocampus of Alzheimer's patients by confocal and ultrastructural analysis. We posit that the phagocytic activity of reactive astrocytes might contribute to clear dysfunctional synapses or synaptic debris, thereby restoring impaired neural circuits and reducing the inflammatory impact of damaged neuronal parts and/or limiting the amyloid pathology. Therefore, potentiation of the phagocytic properties of reactive astrocytes may represent a potential therapy in Alzheimer's disease. PMID:29178139

Altered Tnnt3 characterizes selective weakness of fast fibers in mice overexpressing FSHD region gene 1 (FRG1)

PubMed Central

Sancisi, Valentina; Germinario, Elena; Esposito, Alessandra; Morini, Elisabetta; Peron, Samantha; Moggio, Maurizio; Tomelleri, Giuliano; Danieli-Betto, Daniela

2013-01-01

Facioscapulohumeral muscular dystrophy (FSHD), a common hereditary myopathy, is characterized by atrophy and weakness of selective muscle groups. FSHD is considered an autosomal dominant disease with incomplete penetrance and unpredictable variability of clinical expression within families. Mice overexpressing FRG1 (FSHD region gene 1), a candidate gene for this disease, develop a progressive myopathy with features of the human disorder. Here, we show that in FRG1-overexpressing mice, fast muscles, which are the most affected by the dystrophic process, display anomalous fast skeletal troponin T (fTnT) isoform, resulting from the aberrant splicing of the Tnnt3 mRNA that precedes the appearance of dystrophic signs. We determine that muscles of FRG1 mice develop less strength due to impaired contractile properties of fast-twitch fibers associated with an anomalous MyHC-actin ratio and a reduced sensitivity to Ca2+. We demonstrate that the decrease of Ca2+ sensitivity of fast-twitch fibers depends on the anomalous troponin complex and can be rescued by the substitution with the wild-type proteins. Finally, we find that the presence of aberrant splicing isoforms of TNNT3 characterizes dystrophic muscles in FSHD patients. Collectively, our results suggest that anomalous TNNT3 profile correlates with the muscle impairment in both humans and mice. On the basis of these results, we propose that aberrant fTnT represents a biological marker of muscle phenotype severity and disease progression. PMID:24305066

Plaque-Associated Local Toxicity Increases over the Clinical Course of Alzheimer Disease

PubMed Central

Serrano-Pozo, Alberto; Betensky, Rebecca A.; Frosch, Matthew P.; Hyman, Bradley T.

2017-01-01

Amyloid (senile) plaques, one of the two pathologic hallmarks of Alzheimer disease (AD), are associated with dystrophic neurites and glial responses, both astrocytic and microglial. Although plaque burden remains relatively stable through the clinical course of AD, whether these features of local plaque toxicity continue to worsen over the course of the disease is unclear. We performed an unbiased plaque-centered quantification of SMI312+ dystrophic neurites, GFAP+ reactive astrocytes, and IBA1+ and CD68+ activated microglia in randomly selected dense-core (Thioflavin-S+) plaques from the temporal neocortex of 40 AD subjects with a symptom duration ranging from 4 to 20 years, and nine nondemented control subjects with dense-core plaques. Dystrophic neurites (Kendall τ = 0.34, P = 0.001), reactive astrocytes (Kendall τ = 0.30, P = 0.003), and CD68+ (Kendall τ = 0.48, P < 0.0001), but not IBA1 microglia (Kendall τ = 0.045, P = 0.655), exhibited a significant positive correlation with symptom duration. When excluding control subjects, only the positive association between CD68+ microglia and symptom duration remained significant (Kendall τ = 0.39, P = 0.0003). The presence of the APOEε4 allele did not affect these results. We conclude that plaques exert an increasing toxicity in the surrounding neuropil over the clinical course of AD, thereby potentially contributing to cognitive decline. PMID:26687817

Gentamicin treatment in exercised mdx mice: Identification of dystrophin-sensitive pathways and evaluation of efficacy in work-loaded dystrophic muscle.

PubMed

De Luca, Annamaria; Nico, Beatrice; Rolland, Jean-François; Cozzoli, Anna; Burdi, Rosa; Mangieri, Domenica; Giannuzzi, Viviana; Liantonio, Antonella; Cippone, Valentina; De Bellis, Michela; Nicchia, Grazia Paola; Camerino, Giulia Maria; Frigeri, Antonio; Svelto, Maria; Camerino, Diana Conte

2008-11-01

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.

piggyBac transposons expressing full-length human dystrophin enable genetic correction of dystrophic mesoangioblasts.

PubMed

Loperfido, Mariana; Jarmin, Susan; Dastidar, Sumitava; Di Matteo, Mario; Perini, Ilaria; Moore, Marc; Nair, Nisha; Samara-Kuko, Ermira; Athanasopoulos, Takis; Tedesco, Francesco Saverio; Dickson, George; Sampaolesi, Maurilio; VandenDriessche, Thierry; Chuah, Marinee K

2016-01-29

Duchenne muscular dystrophy (DMD) is a genetic neuromuscular disorder caused by the absence of dystrophin. We developed a novel gene therapy approach based on the use of the piggyBac (PB) transposon system to deliver the coding DNA sequence (CDS) of either full-length human dystrophin (DYS: 11.1 kb) or truncated microdystrophins (MD1: 3.6 kb; MD2: 4 kb). PB transposons encoding microdystrophins were transfected in C2C12 myoblasts, yielding 65±2% MD1 and 66±2% MD2 expression in differentiated multinucleated myotubes. A hyperactive PB (hyPB) transposase was then deployed to enable transposition of the large-size PB transposon (17 kb) encoding the full-length DYS and green fluorescence protein (GFP). Stable GFP expression attaining 78±3% could be achieved in the C2C12 myoblasts that had undergone transposition. Western blot analysis demonstrated expression of the full-length human DYS protein in myotubes. Subsequently, dystrophic mesoangioblasts from a Golden Retriever muscular dystrophy dog were transfected with the large-size PB transposon resulting in 50±5% GFP-expressing cells after stable transposition. This was consistent with correction of the differentiated dystrophic mesoangioblasts following expression of full-length human DYS. These results pave the way toward a novel non-viral gene therapy approach for DMD using PB transposons underscoring their potential to deliver large therapeutic genes. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Amyloid load and neural elements in Alzheimer's disease and nondemented individuals with high amyloid plaque density.

PubMed

Mochizuki, A; Peterson, J W; Mufson, E J; Trapp, B D

1996-11-01

The amyloid burden and relationship between amyloid deposits and neural elements were investigated in sections of prefrontal neocortex from eight Alzheimer's disease (AD) patients and four age-matched nondemented controls with high amyloid plaque density (HPND). Computer-based image analysis revealed that the total area occupied by betaA4 immunoreactivity was significantly greater (P < 0.031) in AD (27.1%) than in HPND (14.5%) sections. The total betaA4-positive area occupied by nondiffuse plaques was significantly greater (P < 0.05) in AD (13.6%) than in HPND (5.2%) sections. The percentage of diffuse (DPs) and nondiffuse plaques (NDPs) which contained neurons, astrocytes, microglia, dystrophic neurites, and amyloid precursor protein (APP) was also determined. The frequency of association between betaA4 and these neural elements was similar between AD and HPND cases in both diffuse and nondiffuse plaques. Forty percent of DPs in AD and HPND sections contained neuronal perikarya. Microglia, dystrophic neurites, and APP were detected in most nondiffuse plaques in both AD and HPND sections. While astrocyte cell bodies were not present in either diffuse or nondiffuse plaques, their processes were detected in most. These findings indicate that amyloid deposition and nondiffuse plaques are greater in AD than in HPND sections. The association between microglia and nondiffuse plaques supports the hypothesis that these resident immune cells participate in aggregation and redistribution of amyloid deposits and possibly formation of dystrophic neurites.

Physical and chemical consequences of artificially deepened thermocline in a small humic lake - a paired whole-lake climate change experiment

NASA Astrophysics Data System (ADS)

Forsius, M.; Saloranta, T.; Arvola, L.; Salo, S.; Verta, M.; Ala-Opas, P.; Rask, M.; Vuorenmaa, J.

2010-05-01

Climate change with higher air temperatures and changes in cloud cover, radiation and wind speed alters the heat balance and stratification patterns of lakes. A paired whole-lake thermocline manipulation experiment of a small (0.047 km2) shallow dystrophic lake (Halsjärvi) was carried out in southern Finland. A thermodynamic model (MyLake) was used for both predicting the impacts of climate change scenarios and for determining the manipulation target of the experiment. The model simulations assuming several climate change scenarios indicated large increases in the whole-lake monthly mean temperature (+1.4-4.4 °C in April-October for the A2 scenario), and shortening of the length of the ice covered period by 56-89 days. The thermocline manipulation resulted in large changes in the thermodynamic properties of the lake, and those were rather well consistent with the simulated future increases in the heat content during the summer-autumn season. The manipulation also resulted in changes in the oxygen stratification, and the expansion of the oxic water layer increased the spatial extent of the sediment surface oxic-anoxic interfaces. The experiment also affected several other chemical constituents; concentrations of TotN, NH4 and organic carbon showed a statistically significant decrease, likely due to both unusual hydrological conditions during the experiment period and increased decomposition and sedimentation. Changes in mercury processes and in the aquatic food web were also introduced. In comparison with the results of a similar whole-lake manipulation experiment in a deep, oligotrophic, clear-watered lake in Norway, it is evident that shallow dystrophic lakes, common in the boreal region, are more sensitive to physical perturbations. This means that projected climate change may strongly modify their physical and chemical conditions in the future.

Cerebral amyloid-beta protein accumulation with aging in cotton-top tamarins: a model of early Alzheimer's disease?

PubMed

Lemere, Cynthia A; Oh, Jiwon; Stanish, Heather A; Peng, Ying; Pepivani, Imelda; Fagan, Anne M; Yamaguchi, Haruyasu; Westmoreland, Susan V; Mansfield, Keith G

2008-04-01

Alzheimer's disease (AD) is the most common progressive form of dementia in the elderly. Two major neuropathological hallmarks of AD include cerebral deposition of amyloid-beta protein (Abeta) into plaques and blood vessels, and the presence of neurofibrillary tangles in brain. In addition, activated microglia and reactive astrocytes are often associated with plaques and tangles. Numerous other proteins are associated with plaques in human AD brain, including Apo E and ubiquitin. The amyloid precursor protein and its shorter fragment, Abeta, are homologous between humans and non-human primates. Cerebral Abeta deposition has been reported previously for rhesus monkeys, vervets, squirrel monkeys, marmosets, lemurs, cynomologous monkeys, chimpanzees, and orangutans. Here we report, for the first time, age-related neuropathological changes in cotton-top tamarins (CTT, Saguinus oedipus), an endangered non-human primate native to the rainforests of Colombia and Costa Rica. Typical lifespan is 13-14 years of age in the wild and 15-20+ years in captivity. We performed detailed immunohistochemical analyses of Abeta deposition and associated pathogenesis in archived brain sections from 36 tamarins ranging in age from 6-21 years. Abeta plaque deposition was observed in 16 of the 20 oldest tamarins (>12 years). Plaques contained mainly Abeta42, and in the oldest animals, were associated with reactive astrocytes, activated microglia, Apo E, and ubiquitin-positive dystrophic neurites, similar to human plaques. Vascular Abeta was detected in 14 of the 20 aged tamarins; Abeta42 preceded Abeta40 deposition. Phospho-tau labeled dystrophic neurites and tangles, typically present in human AD, were absent in the tamarins. In conclusion, tamarins may represent a model of early AD pathology.

Effects of systemic multiexon skipping with peptide-conjugated morpholinos in the heart of a dog model of Duchenne muscular dystrophy

PubMed Central

Echigoya, Yusuke; Nakamura, Akinori; Nagata, Tetsuya; Urasawa, Nobuyuki; Trieu, Nhu; Panesar, Dharminder; Kuraoka, Mutsuki; Moulton, Hong M.; Saito, Takashi; Aoki, Yoshitsugu; Iversen, Patrick; Sazani, Peter; Kole, Ryszard; Maruyama, Rika; Partridge, Terry; Takeda, Shin’ichi; Yokota, Toshifumi

2017-01-01

Duchenne muscular dystrophy (DMD) is a lethal genetic disorder caused by an absence of the dystrophin protein in bodywide muscles, including the heart. Cardiomyopathy is a leading cause of death in DMD. Exon skipping via synthetic phosphorodiamidate morpholino oligomers (PMOs) represents one of the most promising therapeutic options, yet PMOs have shown very little efficacy in cardiac muscle. To increase therapeutic potency in cardiac muscle, we tested a next-generation morpholino: arginine-rich, cell-penetrating peptide-conjugated PMOs (PPMOs) in the canine X-linked muscular dystrophy in Japan (CXMDJ) dog model of DMD. A PPMO cocktail designed to skip dystrophin exons 6 and 8 was injected intramuscularly, intracoronarily, or intravenously into CXMDJ dogs. Intravenous injections with PPMOs restored dystrophin expression in the myocardium and cardiac Purkinje fibers, as well as skeletal muscles. Vacuole degeneration of cardiac Purkinje fibers, as seen in DMD patients, was ameliorated in PPMO-treated dogs. Although symptoms and functions in skeletal muscle were not ameliorated by i.v. treatment, electrocardiogram abnormalities (increased Q-amplitude and Q/R ratio) were improved in CXMDJ dogs after intracoronary or i.v. administration. No obvious evidence of toxicity was found in blood tests throughout the monitoring period of one or four systemic treatments with the PPMO cocktail (12 mg/kg/injection). The present study reports the rescue of dystrophin expression and recovery of the conduction system in the heart of dystrophic dogs by PPMO-mediated multiexon skipping. We demonstrate that rescued dystrophin expression in the Purkinje fibers leads to the improvement/prevention of cardiac conduction abnormalities in the dystrophic heart. PMID:28373570

Effects of systemic multiexon skipping with peptide-conjugated morpholinos in the heart of a dog model of Duchenne muscular dystrophy.

PubMed

Echigoya, Yusuke; Nakamura, Akinori; Nagata, Tetsuya; Urasawa, Nobuyuki; Lim, Kenji Rowel Q; Trieu, Nhu; Panesar, Dharminder; Kuraoka, Mutsuki; Moulton, Hong M; Saito, Takashi; Aoki, Yoshitsugu; Iversen, Patrick; Sazani, Peter; Kole, Ryszard; Maruyama, Rika; Partridge, Terry; Takeda, Shin'ichi; Yokota, Toshifumi

2017-04-18

Duchenne muscular dystrophy (DMD) is a lethal genetic disorder caused by an absence of the dystrophin protein in bodywide muscles, including the heart. Cardiomyopathy is a leading cause of death in DMD. Exon skipping via synthetic phosphorodiamidate morpholino oligomers (PMOs) represents one of the most promising therapeutic options, yet PMOs have shown very little efficacy in cardiac muscle. To increase therapeutic potency in cardiac muscle, we tested a next-generation morpholino: arginine-rich, cell-penetrating peptide-conjugated PMOs (PPMOs) in the canine X-linked muscular dystrophy in Japan (CXMD J ) dog model of DMD. A PPMO cocktail designed to skip dystrophin exons 6 and 8 was injected intramuscularly, intracoronarily, or intravenously into CXMD J dogs. Intravenous injections with PPMOs restored dystrophin expression in the myocardium and cardiac Purkinje fibers, as well as skeletal muscles. Vacuole degeneration of cardiac Purkinje fibers, as seen in DMD patients, was ameliorated in PPMO-treated dogs. Although symptoms and functions in skeletal muscle were not ameliorated by i.v. treatment, electrocardiogram abnormalities (increased Q-amplitude and Q/R ratio) were improved in CXMD J dogs after intracoronary or i.v. administration. No obvious evidence of toxicity was found in blood tests throughout the monitoring period of one or four systemic treatments with the PPMO cocktail (12 mg/kg/injection). The present study reports the rescue of dystrophin expression and recovery of the conduction system in the heart of dystrophic dogs by PPMO-mediated multiexon skipping. We demonstrate that rescued dystrophin expression in the Purkinje fibers leads to the improvement/prevention of cardiac conduction abnormalities in the dystrophic heart.

Divergent impact of Toll-like receptor 2 deficiency on repair mechanisms in healthy muscle versus Duchenne muscular dystrophy.

PubMed

Mojumdar, Kamalika; Giordano, Christian; Lemaire, Christian; Liang, Feng; Divangahi, Maziar; Qureshi, Salman T; Petrof, Basil J

2016-05-01

Injury to skeletal muscle, whether acute or chronic, triggers macrophage-mediated innate immunity in a manner which can be either beneficial or harmful for subsequent repair. Endogenous ligands for Toll-like receptor 2 (TLR2) are released by damaged tissues and might play an important role in activating the innate immune system following muscle injury. To test this hypothesis, we compared macrophage behaviour and muscle repair mechanisms in mice lacking TLR2 under conditions of either acute (cardiotoxin-induced) or chronic (mdx mouse genetic model of Duchenne muscular dystrophy; DMD) muscle damage. In previously healthy muscle subjected to acute damage, TLR2 deficiency reduced macrophage numbers in the muscle post-injury but did not alter the expression pattern of the prototypical macrophage polarization markers iNOS and CD206. In addition, there was abnormal persistence of necrotic fibres and impaired regeneration in TLR2-/- muscles after acute injury. In contrast, TLR2 ablation in chronically diseased muscles of mdx mice not only resulted in significantly reduced macrophage numbers but additionally modified their phenotype by shifting from inflammatory (iNOS(pos) CD206(neg) ) to more anti-inflammatory (iNOS(neg) CD206(pos) ) characteristics. This decrease in macrophage-mediated inflammation was associated with ameliorated muscle histopathology and improved force-generating capacity of the dystrophic muscle. Our results suggest that the role of TLR2 in macrophage function and skeletal muscle repair depends greatly upon the muscle injury context, and raise the possibility that inhibition of TLR2 could serve as a useful therapeutic measure in DMD. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Tadalafil alleviates muscle ischemia in patients with Becker muscular dystrophy.

PubMed

Martin, Elizabeth A; Barresi, Rita; Byrne, Barry J; Tsimerinov, Evgeny I; Scott, Bryan L; Walker, Ashley E; Gurudevan, Swaminatha V; Anene, Francine; Elashoff, Robert M; Thomas, Gail D; Victor, Ronald G

2012-11-28

Becker muscular dystrophy (BMD) is a progressive X-linked muscle wasting disease for which there is no treatment. Like Duchenne muscular dystrophy (DMD), BMD is caused by mutations in the gene encoding dystrophin, a structural cytoskeletal protein that also targets other proteins to the muscle sarcolemma. Among these is neuronal nitric oxide synthase (nNOSμ), which requires certain spectrin-like repeats in dystrophin's rod domain and the adaptor protein α-syntrophin to be targeted to the sarcolemma. When healthy skeletal muscle is subjected to exercise, sarcolemmal nNOSμ-derived NO attenuates local α-adrenergic vasoconstriction, thereby optimizing perfusion of muscle. We found previously that this protective mechanism is defective-causing functional muscle ischemia-in dystrophin-deficient muscles of the mdx mouse (a model of DMD) and of children with DMD, in whom nNOSμ is mislocalized to the cytosol instead of the sarcolemma. We report that this protective mechanism also is defective in men with BMD in whom the most common dystrophin mutations disrupt sarcolemmal targeting of nNOSμ. In these men, the vasoconstrictor response, measured as a decrease in muscle oxygenation, to reflex sympathetic activation is not appropriately attenuated during exercise of the dystrophic muscles. In a randomized placebo-controlled crossover trial, we show that functional muscle ischemia is alleviated and normal blood flow regulation is fully restored in the muscles of men with BMD by boosting NO-cGMP (guanosine 3',5'-monophosphate) signaling with a single dose of the drug tadalafil, a phosphodiesterase 5A inhibitor. These results further support an essential role for sarcolemmal nNOSμ in the normal modulation of sympathetic vasoconstriction in exercising human skeletal muscle and implicate the NO-cGMP pathway as a putative new target for treating BMD.

Formulation of polylactide-co-glycolic acid nanospheres for encapsulation and sustained release of poly(ethylene imine)-poly(ethylene glycol) copolymers complexed to oligonucleotides

PubMed Central

Sirsi, Shashank R; Schray, Rebecca C; Wheatley, Margaret A; Lutz, Gordon J

2009-01-01

Antisense oligonucleotides (AOs) have been shown to induce dystrophin expression in muscles cells of patients with Duchenne Muscular Dystrophy (DMD) and in the mdx mouse, the murine model of DMD. However, ineffective delivery of AOs limits their therapeutic potential. Copolymers of cationic poly(ethylene imine) (PEI) and non-ionic poly(ethylene glycol) (PEG) form stable nanoparticles when complexed with AOs, but the positive surface charge on the resultant PEG-PEI-AO nanoparticles limits their biodistribution. We adapted a modified double emulsion procedure for encapsulating PEG-PEI-AO polyplexes into degradable polylactide-co-glycolic acid (PLGA) nanospheres. Formulation parameters were varied including PLGA molecular weight, ester end-capping, and sonication energy/volume. Our results showed successful encapsulation of PEG-PEI-AO within PLGA nanospheres with average diameters ranging from 215 to 240 nm. Encapsulation efficiency ranged from 60 to 100%, and zeta potential measurements confirmed shielding of the PEG-PEI-AO cationic charge. Kinetic measurements of 17 kDa PLGA showed a rapid burst release of about 20% of the PEG-PEI-AO, followed by sustained release of up to 65% over three weeks. To evaluate functionality, PEG-PEI-AO polyplexes were loaded into PLGA nanospheres using an AO that is known to induce dystrophin expression in dystrophic mdx mice. Intramuscular injections of this compound into mdx mice resulted in over 300 dystrophin-positive muscle fibers distributed throughout the muscle cross-sections, approximately 3.4 times greater than for injections of AO alone. We conclude that PLGA nanospheres are effective compounds for the sustained release of PEG-PEI-AO polyplexes in skeletal muscle and concomitant expression of dystrophin, and may have translational potential in treating DMD. PMID:19351396

High Throughput Screening for Compounds That Alter Muscle Cell Glycosylation Identifies New Role for N-Glycans in Regulating Sarcolemmal Protein Abundance and Laminin Binding*

PubMed Central

Cabrera, Paula V.; Pang, Mabel; Marshall, Jamie L.; Kung, Raymond; Nelson, Stanley F.; Stalnaker, Stephanie H.; Wells, Lance; Crosbie-Watson, Rachelle H.; Baum, Linda G.

2012-01-01

Duchenne muscular dystrophy is an X-linked disorder characterized by loss of dystrophin, a cytoskeletal protein that connects the actin cytoskeleton in skeletal muscle cells to extracellular matrix. Dystrophin binds to the cytoplasmic domain of the transmembrane glycoprotein β-dystroglycan (β-DG), which associates with cell surface α-dystroglycan (α-DG) that binds laminin in the extracellular matrix. β-DG can also associate with utrophin, and this differential association correlates with specific glycosylation changes on α-DG. Genetic modification of α-DG glycosylation can promote utrophin binding and rescue dystrophic phenotypes in mouse dystrophy models. We used high throughput screening with the plant lectin Wisteria floribunda agglutinin (WFA) to identify compounds that altered muscle cell surface glycosylation, with the goal of finding compounds that increase abundance of α-DG and associated sarcolemmal glycoproteins, increase utrophin usage, and increase laminin binding. We identified one compound, lobeline, from the Prestwick library of Food and Drug Administration-approved compounds that fulfilled these criteria, increasing WFA binding to C2C12 cells and to primary muscle cells from wild type and mdx mice. WFA binding and enhancement by lobeline required complex N-glycans but not O-mannose glycans that bind laminin. However, inhibiting complex N-glycan processing reduced laminin binding to muscle cell glycoproteins, although O-mannosylation was intact. Glycan analysis demonstrated a general increase in N-glycans on lobeline-treated cells rather than specific alterations in cell surface glycosylation, consistent with increased abundance of multiple sarcolemmal glycoproteins. This demonstrates the feasibility of high throughput screening with plant lectins to identify compounds that alter muscle cell glycosylation and identifies a novel role for N-glycans in regulating muscle cell function. PMID:22570487

Tadalafil alleviates muscle ischemia in patients with Becker muscular dystrophy

PubMed Central

Martin, Elizabeth A.; Barresi, Rita; Byrne, Barry J.; Tsimerinov, Evgeny I.; Scott, Bryan L.; Walker, Ashley E.; Gurudevan, Swaminatha V.; Anene, Francine; Elashoff, Robert M.; Thomas, Gail D.; Victor, Ronald G.

2013-01-01

Becker muscular dystrophy (BMD) is a progressive X-linked muscle wasting disease for which there is no treatment. Like Duchenne muscular dystrophy (DMD), BMD is caused by mutations in the gene encoding dystrophin, a structural cytoskeletal protein that also targets other proteins to the muscle sarcolemma. Among these is neuronal nitric oxide synthase (nNOSμ), which requires certain spectrin-like repeats in dystrophin’s rod domain and the adaptor protein α-syntrophin to be targeted to the sarcolemma. When healthy skeletal muscle is subjected to exercise, sarcolemmal nNOSμ-derived nitric oxide (NO) attenuates local α-adrenergic vasoconstriction thereby optimizing perfusion of muscle. We found previously that this protective mechanism is defective—causing functional muscle ischemia—in dystrophin-deficient muscles of the mdx mouse (a model of DMD) and of children with DMD, in whom nNOSμ is mislocalized to the cytosol instead of the sarcolemma. Here, we report that this protective mechanism also is defective in men with BMD in whom the most common dystrophin mutations disrupt sarcolemmal targeting of nNOSμ. In these men, the vasoconstrictor response, measured as a decrease in muscle oxygenation, to reflex sympathetic activation is not appropriately attenuated during exercise of the dystrophic muscles. In a randomized placebo-controlled cross-over trial, we show that functional muscle ischemia is alleviated and normal blood flow regulation fully restored in the muscles of men with BMD by boosting NO-cGMP signaling with a single dose of the drug tadalafil, a phosphodiesterase (PDE5A) inhibitor. These results further support an essential role for sarcolemmal nNOSμ in the normal modulation of sympathetic vasoconstriction in exercising human skeletal muscle and implicate the NO-cGMP pathway as a putative new target for treating BMD. PMID:23197572

Skeletal muscle contractile properties in a novel murine model for limb girdle muscular dystrophy 2i.

PubMed

Rehwaldt, Jordan D; Rodgers, Buel D; Lin, David C

2017-12-01

Limb-girdle muscular dystrophy (LGMD) 2i results from mutations in fukutin-related protein and aberrant α-dystroglycan glycosylation. Although this significantly compromises muscle function and ambulation, the comprehensive characteristics of contractile dysfunction are unknown. Therefore, we quantified the in situ contractile properties of the medial gastrocnemius in young adult P448L mice, an affected muscle of a novel model of LGMD2i. Normalized maximal twitch force, tetanic force, and power were significantly smaller in P448L mice, compared with sex-matched, wild-type mice. These differences were consistent with the replacement of contractile fibers by passive tissue. The shape of the active force-length relationships were similar in both groups, regardless of sex, consistent with an intact sarcomeric structure in P448L mice. Passive force-length curves normalized to maximal isometric force were steeper in P448L mice, and passive elements contribute disproportionately more to total contractile force in P448L mice. Sex differences were mostly noted in the force-velocity curves, as normalized values for maximal and optimal velocities were significantly slower in P448L males, compared with wild-type, but not in P448L females. This suggests that the dystrophic phenotype, which may include possible changes in cross-bridge kinetics and fiber-type proportions, progresses more quickly in P448L males. These results together indicate that active force and power generation are compromised in both sexes of P448L mice, while passive forces increase. More importantly, the results identified several functional markers of disease pathophysiology that could aid in developing and assessment of novel therapeutics for LGMD2i and possibly other dystroglycanopathies as well. NEW & NOTEWORTHY Comprehensive assessments of muscle contractile function have, until now, never been performed in an animal model for any dystroglycanopathy. This study suggests that skeletal muscle contractile properties are significantly compromised in a recently developed model for limb-girdle muscular dystrophy 2i, the P448L mouse. It further identifies novel pathological markers of muscle function that are suitable for developing therapeutics and for better understanding of disease pathogenesis.

Junctional epidermolysis bullosa incidence and survival: 5-year experience of the Dystrophic Epidermolysis Bullosa Research Association of America (DebRA) nurse educator, 2007 to 2011.

PubMed

Kelly-Mancuso, Geraldine; Kopelan, Brett; Azizkhan, Richard G; Lucky, Anne W

2014-01-01

Junctional epidermolysis bullosa (JEB) is a particularly devastating type of epidermolysis bullosa, especially in the newborn period. Data about the number of new cases of JEB in the United States were collected from the records of the Dystrophic Epidermolysis Bullosa Research Association of America (DebRA) nurse educator. Seventy-one children with JEB were reported to have been born in the 5 years between 2007 and 2011, reflecting an incidence of at least 3.59 per million per year, significantly higher than previously estimated (2.04 per million). There was a high prevalence of morbidity and infant mortality of at least 73%, as 52 of the 71 cases proved fatal by June 2012. These data emphasize the need for future research to develop treatment and ultimately a cure for this disorder. © 2013 Wiley Periodicals, Inc.

Genome-wide Mechanosensitive MicroRNA (MechanomiR) Screen Uncovers Dysregulation of Their Regulatory Networks in the mdm Mouse Model of Muscular Dystrophy*

PubMed Central

Mohamed, Junaith S.; Hajira, Ameena; Lopez, Michael A.; Boriek, Aladin M.

2015-01-01

Muscular dystrophies (MDs) are a heterogeneous group of genetic and neuromuscular disorders, which result in severe loss of motor ability and skeletal muscle mass and function. Aberrant mechanotransduction and dysregulated-microRNA pathways are often associated with the progression of MD. Here, we hypothesized that dysregulation of mechanosensitive microRNAs (mechanomiRs) in dystrophic skeletal muscle plays a major role in the progression of MD. To test our hypothesis, we performed a genome-wide expression profile of anisotropically regulated mechanomiRs and bioinformatically analyzed their target gene networks. We assessed their functional roles in the advancement of MD using diaphragm muscles from mdm (MD with myositis) mice, an animal model of human tibial MD (titinopathy), and their wild-type littermates. We were able to show that ex vivo anisotropic mechanical stretch significantly alters the miRNA expression profile in diaphragm muscles from WT and mdm mice; as a result, some of the genes associated with MDs are dysregulated in mdm mice due to differential regulation of a distinct set of mechanomiRs. Interestingly, we found a contrasting expression pattern of the highly expressed let-7 family mechanomiRs, let-7e-5p and miR-98–5p, and their target genes associated with the extracellular matrix and TGF-β pathways, respectively, between WT and mdm mice. Gain- and loss-of-function analysis of let-7e-5p in myocytes isolated from the diaphragms of WT and mdm mice confirmed Col1a1, Col1a2, Col3a1, Col24a1, Col27a1, Itga1, Itga4, Scd1, and Thbs1 as target genes of let-7e-5p. Furthermore, we found that miR-98 negatively regulates myoblast differentiation. Our study therefore introduces additional biological players in the regulation of skeletal muscle structure and myogenesis that may contribute to unexplained disorders of MD. PMID:26272747

Genetic correction of dystrophin deficiency and skeletal muscle remodeling in adult MDX mouse via transplantation of retroviral producer cells.

PubMed Central

Fassati, A; Wells, D J; Sgro Serpente, P A; Walsh, F S; Brown, S C; Strong, P N; Dickson, G

1997-01-01

Duchenne muscular dystrophy (DMD) is an X-linked, lethal disease caused by mutations of the dystrophin gene. No effective therapy is available, but dystrophin gene transfer to skeletal muscle has been proposed as a treatment for DMD. We have developed a strategy for efficient in vivo gene transfer of dystrophin cDNA into regenerating skeletal muscle. Retroviral producer cells, which release a vector carrying the therapeutically active dystrophin minigene, were mitotically inactivated and transplanted in adult nude/mdx mice. Transplantation of 3 x 10(6) producer cells in a single site of the tibialis anterior muscle resulted in the transduction of between 5.5 and 18% total muscle fibers. The same procedure proved also feasible in immunocompetent mdx mice under short-term pharmacological immunosuppression. Minidystrophin expression was stable for up to 6 mo and led to alpha-sarcoglycan reexpression. Muscle stem cells could be transduced in vivo using this procedure. Transduced dystrophic skeletal muscle showed evidence of active remodeling reminiscent of the genetic normalization process which takes place in female DMD carriers. Overall, these results demonstrate that retroviral-mediated dystrophin gene transfer via transplantation of producer cells is a valid approach towards the long-term goal of gene therapy of DMD. PMID:9239410

Differential expression of utrophin-A and -B promoters in the central nervous system (CNS) of normal and dystrophic mdx mice.

PubMed

Baby, Santhosh M; Bogdanovich, Sasha; Willmann, Gabriel; Basu, Utpal; Lozynska, Olga; Khurana, Tejvir S

2010-03-01

Utrophin (Utrn) is the autosomal homolog of dystrophin, the Duchene Muscular Dystrophy (DMD) locus product and of therapeutic interest, as its overexpression can compensate dystrophin's absence. Utrn is transcribed by Utrn-A and -B promoters with mRNAs differing at their 5' ends. However, previous central nervous system (CNS) studies used C-terminal antibodies recognizing both isoforms. As this distinction may impact upregulation strategies, we generated Utrn-A and -B promoter-specific antibodies, Taqman Polymerase chain reaction (PCR)-based absolute copy number assays, and luciferase-reporter constructs to study CNS of normal and dystrophic mdx mice. Differential expression of Utrn-A and -B was noted in microdissected and capillary-enriched fractions. At the protein level, Utrn-B was predominantly expressed in vasculature and ependymal lining, whereas Utrn-A was expressed in neurons, astrocytes, choroid plexus and pia mater. mRNA quantification demonstrated matching patterns of differential expression; however, transcription-translation mismatch was noted for Utrn-B in caudal brain regions. Utrn-A and Utrn-B proteins were significantly upregulated in olfactory bulb and cerebellum of mdx brain. Differential promoter activity, mRNA and protein expressions were studied in cultured C2C12, bEnd3, neurons and astrocytes. Promoter activity ranking for Utrn-A and -B was neurons > astrocytes > C2C12 > bEnd3 and bEnd3 > astrocytes > neurons > C2C12, respectively. Our results identify promoter usage patterns for therapeutic targeting and define promoter-specific differential distribution of Utrn isoforms in normal and dystrophic CNS.

Repression of phosphatidylinositol transfer protein α ameliorates the pathology of Duchenne muscular dystrophy.

PubMed

Vieira, Natassia M; Spinazzola, Janelle M; Alexander, Matthew S; Moreira, Yuri B; Kawahara, Genri; Gibbs, Devin E; Mead, Lillian C; Verjovski-Almeida, Sergio; Zatz, Mayana; Kunkel, Louis M

2017-06-06

Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disease caused by X-linked inherited mutations in the DYSTROPHIN ( DMD ) gene. Absence of dystrophin protein from the sarcolemma causes severe muscle degeneration, fibrosis, and inflammation, ultimately leading to cardiorespiratory failure and premature death. Although there are several promising strategies under investigation to restore dystrophin protein expression, there is currently no cure for DMD, and identification of genetic modifiers as potential targets represents an alternative therapeutic strategy. In a Brazilian golden retriever muscular dystrophy (GRMD) dog colony, two related dogs demonstrated strikingly mild dystrophic phenotypes compared with those typically observed in severely affected GRMD dogs despite lacking dystrophin. Microarray analysis of these "escaper" dogs revealed reduced expression of phosphatidylinositol transfer protein-α ( PITPNA ) in escaper versus severely affected GRMD dogs. Based on these findings, we decided to pursue investigation of modulation of PITPNA expression on dystrophic pathology in GRMD dogs, dystrophin-deficient sapje zebrafish, and human DMD myogenic cells. In GRMD dogs, decreased expression of Pitpna was associated with increased phosphorylated Akt (pAkt) expression and decreased PTEN levels. PITPNA knockdown by injection of morpholino oligonucleotides in sapje zebrafish also increased pAkt, rescued the abnormal muscle phenotype, and improved long-term sapje mutant survival. In DMD myotubes, PITPNA knockdown by lentiviral shRNA increased pAkt and increased myoblast fusion index. Overall, our findings suggest PIPTNA as a disease modifier that accords benefits to the abnormal signaling, morphology, and function of dystrophic skeletal muscle, and may be a target for DMD and related neuromuscular diseases.

Overexpression of a calpastatin transgene in mdx muscle reduces dystrophic pathology.

PubMed

Spencer, Melissa J; Mellgren, Ronald L

2002-10-01

Reduced sarcolemmal integrity in dystrophin-deficient muscles of mdx mice and Duchenne muscular dystrophy (DMD) patients has been reported to result in altered calcium homeostasis. Previous studies have shown a correlative relationship between calcium-dependent protease (calpain) activity in dystrophic muscle and muscle necrosis, but have not tested whether calpain activation precedes cell death or is a consequence of it. To test a causal relationship between calpain activation and muscle cell death in dystrophin deficiency, mdx mice were generated that overexpress a calpastatin transgene in muscle. Calpastatin (CS) is a specific, endogenous inhibitor of m- and micro -calpains that does not inhibit calpain 3 (p94). CS overexpression on a C57/BL 10 background produced no phenotype. Transgenic (Tg) mice crossed with mdx mice were tested for pathological indicators of necrosis, regeneration and membrane damage. Two lines of mice were examined, with different levels of CS overexpression. Both lines of Tg/mdx mice showed reductions in muscle necrosis at 4 weeks of age. These mice had fewer as well as smaller lesions. In addition, one line of mice had significantly less regeneration, indicating a reduction in previous necrosis. The extent of improvement correlated with the level of CS protein expression. Membrane damage, as assessed by procion orange and creatine kinase assays, was unchanged, supporting the idea that calpains act downstream of the primary muscle defect. These data suggest that calpains play an active role in necrotic processes in dystrophic muscle and that inhibition of calpains might provide a good therapeutic option for treatment of DMD.

Repression of phosphatidylinositol transfer protein α ameliorates the pathology of Duchenne muscular dystrophy

PubMed Central

Vieira, Natassia M.; Spinazzola, Janelle M.; Alexander, Matthew S.; Moreira, Yuri B.; Kawahara, Genri; Gibbs, Devin E.; Mead, Lillian C.; Zatz, Mayana; Kunkel, Louis M.

2017-01-01

Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disease caused by X-linked inherited mutations in the DYSTROPHIN (DMD) gene. Absence of dystrophin protein from the sarcolemma causes severe muscle degeneration, fibrosis, and inflammation, ultimately leading to cardiorespiratory failure and premature death. Although there are several promising strategies under investigation to restore dystrophin protein expression, there is currently no cure for DMD, and identification of genetic modifiers as potential targets represents an alternative therapeutic strategy. In a Brazilian golden retriever muscular dystrophy (GRMD) dog colony, two related dogs demonstrated strikingly mild dystrophic phenotypes compared with those typically observed in severely affected GRMD dogs despite lacking dystrophin. Microarray analysis of these “escaper” dogs revealed reduced expression of phosphatidylinositol transfer protein-α (PITPNA) in escaper versus severely affected GRMD dogs. Based on these findings, we decided to pursue investigation of modulation of PITPNA expression on dystrophic pathology in GRMD dogs, dystrophin-deficient sapje zebrafish, and human DMD myogenic cells. In GRMD dogs, decreased expression of Pitpna was associated with increased phosphorylated Akt (pAkt) expression and decreased PTEN levels. PITPNA knockdown by injection of morpholino oligonucleotides in sapje zebrafish also increased pAkt, rescued the abnormal muscle phenotype, and improved long-term sapje mutant survival. In DMD myotubes, PITPNA knockdown by lentiviral shRNA increased pAkt and increased myoblast fusion index. Overall, our findings suggest PIPTNA as a disease modifier that accords benefits to the abnormal signaling, morphology, and function of dystrophic skeletal muscle, and may be a target for DMD and related neuromuscular diseases. PMID:28533404

Loss of nNOS inhibits compensatory muscle hypertrophy and exacerbates inflammation and eccentric contraction-induced damage in mdx mice

PubMed Central

Froehner, Stanley C.; Reed, Sarah M.; Anderson, Kendra N.; Huang, Paul L.; Percival, Justin M.

2015-01-01

Approaches targeting nitric oxide (NO) signaling show promise as therapies for Duchenne and Becker muscular dystrophies. However, the mechanisms by which NO benefits dystrophin-deficient muscle remain unclear, but may involve nNOSβ, a newly discovered enzymatic source of NO in skeletal muscle. Here we investigate the impact of dystrophin deficiency on nNOSβ and use mdx mice engineered to lack nNOSμ and nNOSβ to discern how the loss of nNOS impacts dystrophic skeletal muscle pathology. In mdx muscle, nNOSβ was mislocalized and its association with the Golgi complex was reduced. nNOS depletion from mdx mice prevented compensatory skeletal muscle cell hypertrophy, decreased myofiber central nucleation and increased focal macrophage cell infiltration, indicating exacerbated dystrophic muscle damage. Reductions in muscle integrity in nNOS-null mdx mice were accompanied by decreases in specific force and increased susceptibility to eccentric contraction-induced muscle damage compared with mdx controls. Unexpectedly, muscle fatigue was unaffected by nNOS depletion, revealing a novel latent compensatory mechanism for the loss of nNOS in mdx mice. Together with previous studies, these data suggest that localization of both nNOSμ and nNOSβ is disrupted by dystrophin deficiency. They also indicate that nNOS has a more complex role as a modifier of dystrophic pathology and broader therapeutic potential than previously recognized. Importantly, these findings also suggest nNOSβ as a new drug target and provide a new conceptual framework for understanding nNOS signaling and the benefits of NO therapies in dystrophinopathies. PMID:25214536

Human papillomavirus infections in vulvar precancerous lesions and cancer.

PubMed

Costa, S; Syrjänen, S; Vendra, C; Chang, F; Guida, G; Hippeläinen, M; Terzano, P; Tervahauta, A; Yliskoski, M; Syrjänen, K

1995-04-01

To elucidate some of the recently arisen issues related to the bimodal disease pattern of vulvar intraepithelial lesions (VIN) and vulvar cancer, a series of 27 consecutive women with vulvar symptoms was analyzed for human papillomavirus (HPV) involvement by colposcopy, light microscopy and in situ hybridization (ISH) for HPV types 6, 11, 16, 18, 31, 33 and 42. Altogether, HPV DNA was discovered in 13/27 (48.1%) of the lesions by ISH; the rest were HPV DNA negative for the seven HPV types tested. HPV DNA was present in both of two exophytic lesions (HPV 6 in condyloma and HPV 16 in verrucous cancer). Of the flat lesions, 7/13 (53.8%) were HPV DNA positive. HPV 6 was confined to low grade lesions (HPV/non-VIN and VIN 1), whereas HPV 11 was found in a case of VIN 3 as well. Of the invasive carcinomas, three of four were HPV DNA positive (2 HPV 16 and 1 HPV 31). Dystrophic changes were detected in three of four invasive carcinomas and in all three HPV 16-positive lesions. Dystrophic changes were absent in 9 of 14 (64.3%) of HPV DNA-negative lesions. Fifty percent (7/14) of vulvar warty lesions (without concomitant VIN) were found in women younger than 60. Three of four invasive carcinomas occurred in women older than 60. This small series provided additional evidence of HPV involvement in the pathogenesis of VIN lesions, and the findings support the hypothesis of a multifactorial etiology in vulvar carcinogenesis in which HPV, dystrophic changes and chronic inflammatory disease play a synergistic role.

Autonomic, locomotor and cardiac abnormalities in a mouse model of muscular dystrophy: targeting the renin-angiotensin system.

PubMed

Sabharwal, Rasna; Chapleau, Mark W

2014-04-01

New Findings What is the topic of this review? This symposium report summarizes autonomic, cardiac and skeletal muscle abnormalities in sarcoglycan-δ-deficient mice (Sgcd-/-), a mouse model of limb girdle muscular dystrophy, with emphasis on the roles of autonomic dysregulation and activation of the renin-angiotensin system at a young age. What advances does it highlight? The contributions of the autonomic nervous system and the renin-angiotensin system to the pathogenesis of muscular dystrophy are highlighted. Results demonstrate that autonomic dysregulation precedes and predicts later development of cardiac dysfunction in Sgcd-/- mice and that treatment of young Sgcd-/- mice with the angiotensin type 1 receptor antagonist losartan or with angiotensin-(1-7) abrogates the autonomic dysregulation, attenuates skeletal muscle pathology and increases spontaneous locomotor activity. Muscular dystrophies are a heterogeneous group of genetic muscle diseases characterized by muscle weakness and atrophy. Mutations in sarcoglycans and other subunits of the dystrophin-glycoprotein complex cause muscular dystrophy and dilated cardiomyopathy in animals and humans. Aberrant autonomic signalling is recognized in a variety of neuromuscular disorders. We hypothesized that activation of the renin-angiotensin system contributes to skeletal muscle and autonomic dysfunction in mice deficient in the sarcoglycan-δ (Sgcd) gene at a young age and that this early autonomic dysfunction contributes to the later development of left ventricular (LV) dysfunction and increased mortality. We demonstrated that young Sgcd-/- mice exhibit histopathological features of skeletal muscle dystrophy, decreased locomotor activity and severe autonomic dysregulation, but normal LV function. Autonomic regulation continued to deteriorate in Sgcd-/- mice with age and was accompanied by LV dysfunction and dilated cardiomyopathy at older ages. Autonomic dysregulation at a young age predicted later development of LV dysfunction and higher mortality in Sgcd-/- mice. Treatment of Sgcd-/- mice with the angiotensin type 1 receptor blocker losartan for 8-9 weeks, beginning at 3 weeks of age, decreased fibrosis and oxidative stress in skeletal muscle, increased locomotor activity and prevented autonomic dysfunction. Chronic infusion of the counter-regulatory peptide angiotensin-(1-7) resulted in similar protection. We conclude that activation of the renin-angiotensin system, at a young age, contributes to skeletal muscle and autonomic dysfunction in muscular dystrophy. We speculate that the latter is mediated via abnormal sensory nerve and/or cytokine signalling from dystrophic skeletal muscle to the brain and contributes to age-related LV dysfunction, dilated cardiomyopathy, arrhythmias and premature death. Therefore, correcting the early autonomic dysregulation and renin-angiotensin system activation may provide a novel therapeutic approach in muscular dystrophy.

Dystrophic (senescent) rather than activated microglial cells are associated with tau pathology and likely precede neurodegeneration in Alzheimer's disease.

PubMed

Streit, Wolfgang J; Braak, Heiko; Xue, Qing-Shan; Bechmann, Ingo

2009-10-01

The role of microglial cells in the pathogenesis of Alzheimer's disease (AD) neurodegeneration is unknown. Although several works suggest that chronic neuroinflammation caused by activated microglia contributes to neurofibrillary degeneration, anti-inflammatory drugs do not prevent or reverse neuronal tau pathology. This raises the question if indeed microglial activation occurs in the human brain at sites of neurofibrillary degeneration. In view of the recent work demonstrating presence of dystrophic (senescent) microglia in aged human brain, the purpose of this study was to investigate microglial cells in situ and at high resolution in the immediate vicinity of tau-positive structures in order to determine conclusively whether degenerating neuronal structures are associated with activated or with dystrophic microglia. We used a newly optimized immunohistochemical method for visualizing microglial cells in human archival brain together with Braak staging of neurofibrillary pathology to ascertain the morphology of microglia in the vicinity of tau-positive structures. We now report histopathological findings from 19 humans covering the spectrum from none to severe AD pathology, including patients with Down's syndrome, showing that degenerating neuronal structures positive for tau (neuropil threads, neurofibrillary tangles, neuritic plaques) are invariably colocalized with severely dystrophic (fragmented) rather than with activated microglial cells. Using Braak staging of Alzheimer neuropathology we demonstrate that microglial dystrophy precedes the spread of tau pathology. Deposits of amyloid-beta protein (Abeta) devoid of tau-positive structures were found to be colocalized with non-activated, ramified microglia, suggesting that Abeta does not trigger microglial activation. Our findings also indicate that when microglial activation does occur in the absence of an identifiable acute central nervous system insult, it is likely to be the result of systemic infectious disease. The findings reported here strongly argue against the hypothesis that neuroinflammatory changes contribute to AD dementia. Instead, they offer an alternative hypothesis of AD pathogenesis that takes into consideration: (1) the notion that microglia are neuron-supporting cells and neuroprotective; (2) the fact that development of non-familial, sporadic AD is inextricably linked to aging. They support the idea that progressive, aging-related microglial degeneration and loss of microglial neuroprotection rather than induction of microglial activation contributes to the onset of sporadic Alzheimer's disease. The results have far-reaching implications in terms of reevaluating current treatment approaches towards AD.

Prosurvival Factors Improve Functional Engraftment of Myogenically Converted Dermal Cells into Dystrophic Skeletal Muscle

PubMed Central

Muir, Lindsey A.; Murry, Charles E.

2016-01-01

In Duchenne muscular dystrophy (DMD) and other muscle wasting disorders, cell therapies are a promising route for promoting muscle regeneration by supplying a functional copy of the missing dystrophin gene and contributing new muscle fibers. The clinical application of cell-based therapies is resource intensive, and it will therefore be necessary to address key limitations that reduce cell engraftment into muscle tissue. A pressing issue is poor donor cell survival following transplantation, which in preclinical studies limits the ability to effectively test the impact of cell-based therapy on whole muscle function. We, therefore, sought to improve engraftment and the functional impact of in vivo myogenically converted dermal fibroblasts (dFbs) using a prosurvival cocktail (PSC) that includes heat shock followed by treatment with insulin-like growth factor-1, a caspase inhibitor, a Bcl-XL peptide, a KATP channel opener, basic fibroblast growth factor, Matrigel, and cyclosporine A. Advantages of dFbs include compatibility with the autologous setting, ease of isolation, and greater proliferative potential than DMD satellite cells. dFbs expressed tamoxifen-inducible MyoD and carried a mini-dystrophin gene driven by a muscle-specific promoter. After transplantation into muscles of mdx mice, a 70% reduction in donor cells was observed by day 5, and a 94% reduction by day 28. However, treatment with PSC gave a nearly three-fold increase in donor cells in early engraftment, and greatly increased the number of donor-contributed muscle fibers and total engrafted area in transplanted muscles. Furthermore, dystrophic muscles that received dFbs with PSC displayed reduced injury with eccentric contractions and an increase in maximum isometric force. Thus, enhancing survival of myogenic cells increases engraftment and improves structure and function of dystrophic muscle. PMID:27503462

Skeletal muscle secretome in Duchenne muscular dystrophy: a pivotal anti-inflammatory role of adiponectin.

PubMed

Lecompte, S; Abou-Samra, M; Boursereau, R; Noel, L; Brichard, S M

2017-07-01

Persistent inflammation exacerbates the progression of Duchenne muscular dystrophy (DMD). The hormone, adiponectin (ApN), which is decreased in the metabolic syndrome, exhibits anti-inflammatory properties on skeletal muscle and alleviates the dystrophic phenotype of mdx mice. Here, we investigate whether ApN retains its anti-inflammatory action in myotubes obtained from DMD patients. We unravel the underlying mechanisms by studying the secretome and the early events of ApN. Primary cultures of myotubes from DMD and control patients were treated or not by ApN after an inflammatory challenge. Myokines secreted in medium were identified by cytokine antibody-arrays and ELISAs. The early events of ApN signaling were assessed by abrogating selected genes. ApN retained its anti-inflammatory properties in both dystrophic and control myotubes. Profiling of secretory products revealed that ApN downregulated the secretion of two pro-inflammatory factors (TNFα and IL-17A), one soluble receptor (sTNFRII), and one chemokine (CCL28) in DMD myotubes, while upregulating IL-6 that exerts some anti-inflammatory effects. These changes were explained by pretranslational mechanisms. Earlier events of the ApN cascade involved AdipoR1, the main receptor for muscle, and the AMPK-SIRT1-PGC-1α axis leading, besides alteration of the myokine profile, to the upregulation of utrophin A (a dystrophin analog). ApN retains its beneficial properties in dystrophic muscles by activating the AdipoR1-AMPK-SIRT1-PGC-1α pathway, thereby inducing a shift in the secretion of downstream myokines toward a less inflammatory profile while upregulating utrophin. ApN, the early events of the cascade and downstream myokines may be therapeutic targets for the management of DMD.

The evaluation of family impact of recessive dystrophic epidermolysis bullosa using the Italian version of the Family Dermatology Life Quality Index.

PubMed

Sampogna, F; Tabolli, S; Di Pietro, C; Castiglia, D; Zambruno, G; Abeni, D

2013-09-01

Severe skin diseases, such as epidermolysis bullosa (EB), may have a strong impact not only on patients but also on caregivers. A specific questionnaire evaluating the family impact of dermatological conditions has been created, the Family Dermatology Life Quality Index (FDLQI), but it has not yet been translated in Italian and validated. To evaluate the burden of recessive dystrophic EB on family caregivers, using for the first time the Italian version of the FDLQI, and to validate the instrument. Patients with recessive dystrophic EB participated in a postal survey enquiring about the burden of EB on family caregivers. They completed the Family Strain Questionnaire and the FDLQI and they marked on a silhouette of the human body the skin lesion distribution. Data on 62 family caregivers were collected. The overall mean FDLQI score was 9.8. The most frequently reported problems were the time spent on looking after the patient, emotional distress, physical well-being, and increased household expenditure. FDLQI scores were higher in family caregivers of patients between 10 and 20 years. The Italian FDLQI showed high internal consistency, construct and convergent validity. Factor analysis revealed the presence of one factor structure underlying the items of the FDLQI, which explained 51.5% of the total variance, very similar to the original questionnaire (55.8%). The Italian version of the FDLQI seems to be a useful tool to evaluate the impact of EB on family caregivers. Further studies are necessary to test this instrument in other dermatological conditions. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.

Muscle Structure Influences Utrophin Expression in mdx Mice

PubMed Central

Banks, Glen B.; Combs, Ariana C.; Odom, Guy L.; Bloch, Robert J.; Chamberlain, Jeffrey S.

2014-01-01

Duchenne muscular dystrophy (DMD) is a severe muscle wasting disorder caused by mutations in the dystrophin gene. To examine the influence of muscle structure on the pathogenesis of DMD we generated mdx4cv:desmin double knockout (dko) mice. The dko male mice died of apparent cardiorespiratory failure at a median age of 76 days compared to 609 days for the desmin−/− mice. An ∼2.5 fold increase in utrophin expression in the dko skeletal muscles prevented necrosis in ∼91% of 1a, 2a and 2d/x fiber-types. In contrast, utrophin expression was reduced in the extrasynaptic sarcolemma of the dko fast 2b fibers leading to increased membrane fragility and dystrophic pathology. Despite lacking extrasynaptic utrophin, the dko fast 2b fibers were less dystrophic than the mdx4cv fast 2b fibers suggesting utrophin-independent mechanisms were also contributing to the reduced dystrophic pathology. We found no overt change in the regenerative capacity of muscle stem cells when comparing the wild-type, desmin−/−, mdx4cv and dko gastrocnemius muscles injured with notexin. Utrophin could form costameric striations with α-sarcomeric actin in the dko to maintain the integrity of the membrane, but the lack of restoration of the NODS (nNOS, α-dystrobrevin 1 and 2, α1-syntrophin) complex and desmin coincided with profound changes to the sarcomere alignment in the diaphragm, deposition of collagen between the myofibers, and impaired diaphragm function. We conclude that the dko mice may provide new insights into the structural mechanisms that influence endogenous utrophin expression that are pertinent for developing a therapy for DMD. PMID:24922526

Disease-related microglia heterogeneity in the hippocampus of Alzheimer's disease, dementia with Lewy bodies, and hippocampal sclerosis of aging.

PubMed

Bachstetter, Adam D; Van Eldik, Linda J; Schmitt, Frederick A; Neltner, Janna H; Ighodaro, Eseosa T; Webster, Scott J; Patel, Ela; Abner, Erin L; Kryscio, Richard J; Nelson, Peter T

2015-05-23

Neuropathological, genetic, and biochemical studies have provided support for the hypothesis that microglia participate in Alzheimer's disease (AD) pathogenesis. Despite the extensive characterization of AD microglia, there are still many unanswered questions, and little is known about microglial morphology in other common forms of age-related dementia: particularly, dementia with Lewy bodies (DLB) and hippocampal sclerosis of aging (HS-Aging). In addition, no prior studies have attempted to compare and contrast the microglia morphology in the hippocampus of various neurodegenerative conditions. Here we studied cases with pathologically-confirmed AD (n = 7), HS-Aging (n = 7), AD + HS-aging (n = 4), DLB (n = 12), and normal (cognitively intact) controls (NC) (n = 9) from the University of Kentucky Alzheimer's Disease Center autopsy cohort. We defined five microglia morphological phenotypes in the autopsy samples: ramified, hypertrophic, dystrophic, rod-shaped, and amoeboid. The Aperio ScanScope digital neuropathological tool was used along with two well-known microglial markers: IBA1 (a marker for both resting and activated microglia) and CD68 (a lysosomal marker in macrophages/microglia associated with phagocytic cells). Hippocampal staining analyses included studies of subregions within the hippocampal formation and nearby white matter. Using these tools and methods, we describe variation in microglial characteristics that show some degree of disease specificity, including, (1) increased microglia density and number in HS-aging and AD + HS-aging; (2) low microglia density in DLB; (3) increased number of dystrophic microglia in HS-aging; and (4) increased proportion of dystrophic to all microglia in DLB. We conclude that variations in morphologies among microglial cells, and cells of macrophage lineage, can help guide future work connecting neuroinflammatory mechanisms with specific neurodegenerative disease subtypes.

Interleukin-6 and neuregulin-1 as regulators of utrophin expression via the activation of NRG-1/ErbB signaling pathway in mdx cells.

PubMed

Juretić, Nevenka; Díaz, Josefina; Romero, Felipe; González, Gustavo; Jaimovich, Enrique; Riveros, Nora

2017-03-01

Duchenne muscular dystrophy (DMD) is a neuromuscular disease originated by mutations in the dystrophin gene. A promising therapeutic approach deals with functional substitution of dystrophin by utrophin, a structural homolog that might be able to compensate dystrophin absence in DMD muscle fibers. It has been described that both interleukin-6 (IL-6) and neuregulin-1 (NRG-1; Heregulin-HRG) induce utrophin expression in skeletal muscle. We investigated a possible functional link among IL-6, NRG-1 and utrophin, in normal (C57) and dystrophic (mdx) skeletal muscle cells. Western Blot analysis allowed us to demonstrate that IL-6 (100ng/mL) induces NRG-1 receptor phosphorylation (ErbB2/ErbB3) in both cell types, in a process that depends on intracellular Ca 2+ and metalloproteinase activity; it also induces a transient increase of ERK1 and GABPα phosphorylation only in dystrophic myotubes. Semiquantitative PCR showed that IL-6 treatment increases utrophin mRNA levels just in mdx myotubes. We observed that utrophin mRNA induction was abolished by BAPTA-AM (an intracellular Ca 2+ chelator), GM6001 (a general metalloproteinase inhibitor), genistein (a general protein tyrosine kinase inhibitor), PD-158780 (an ErbB receptor tyrosine kinase inhibitor) and PD-98059 (a MEK inhibitor), whereas Ly-294002 and wortmannin (PI3K inhibitors) did not affect utrophin induction evoked by IL-6 in dystrophic myotubes. Our results suggest that IL-6 induces utrophin expression in mdx myotubes through activation of a NRG-1/ErbBs signaling cascade. Soluble NRG-1 elicited by proteolytic processing of transmembrane NRG-1 might induce ErbBs phosphorylation and ERK1/2 pathway activation, leading to utrophin up-regulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Multiple pathological events in exercised dystrophic mdx mice are targeted by pentoxifylline: outcome of a large array of in vivo and ex vivo tests.

PubMed

Burdi, Rosa; Rolland, Jean-François; Fraysse, Bodvael; Litvinova, Karina; Cozzoli, Anna; Giannuzzi, Viviana; Liantonio, Antonella; Camerino, Giulia Maria; Sblendorio, Valeriana; Capogrosso, Roberta Francesca; Palmieri, Beniamino; Andreetta, Francesca; Confalonieri, Paolo; De Benedictis, Leonarda; Montagnani, Monica; De Luca, Annamaria

2009-04-01

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 x kg(-1) x 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-beta(1) 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.

Prosurvival Factors Improve Functional Engraftment of Myogenically Converted Dermal Cells into Dystrophic Skeletal Muscle.

PubMed

Muir, Lindsey A; Murry, Charles E; Chamberlain, Jeffrey S

2016-09-07

In Duchenne muscular dystrophy (DMD) and other muscle wasting disorders, cell therapies are a promising route for promoting muscle regeneration by supplying a functional copy of the missing dystrophin gene and contributing new muscle fibers. The clinical application of cell-based therapies is resource intensive, and it will therefore be necessary to address key limitations that reduce cell engraftment into muscle tissue. A pressing issue is poor donor cell survival following transplantation, which in preclinical studies limits the ability to effectively test the impact of cell-based therapy on whole muscle function. We, therefore, sought to improve engraftment and the functional impact of in vivo myogenically converted dermal fibroblasts (dFbs) using a prosurvival cocktail (PSC) that includes heat shock followed by treatment with insulin-like growth factor-1, a caspase inhibitor, a Bcl-XL peptide, a K ATP channel opener, basic fibroblast growth factor, Matrigel, and cyclosporine A. Advantages of dFbs include compatibility with the autologous setting, ease of isolation, and greater proliferative potential than DMD satellite cells. dFbs expressed tamoxifen-inducible MyoD and carried a mini-dystrophin gene driven by a muscle-specific promoter. After transplantation into muscles of mdx mice, a 70% reduction in donor cells was observed by day 5, and a 94% reduction by day 28. However, treatment with PSC gave a nearly three-fold increase in donor cells in early engraftment, and greatly increased the number of donor-contributed muscle fibers and total engrafted area in transplanted muscles. Furthermore, dystrophic muscles that received dFbs with PSC displayed reduced injury with eccentric contractions and an increase in maximum isometric force. Thus, enhancing survival of myogenic cells increases engraftment and improves structure and function of dystrophic muscle.

Finding mouse models of human lymphomas and leukemia's using the Jackson laboratory mouse tumor biology database.

PubMed

Begley, Dale A; Sundberg, John P; Krupke, Debra M; Neuhauser, Steven B; Bult, Carol J; Eppig, Janan T; Morse, Herbert C; Ward, Jerrold M

2015-12-01

Many mouse models have been created to study hematopoietic cancer types. There are over thirty hematopoietic tumor types and subtypes, both human and mouse, with various origins, characteristics and clinical prognoses. Determining the specific type of hematopoietic lesion produced in a mouse model and identifying mouse models that correspond to the human subtypes of these lesions has been a continuing challenge for the scientific community. The Mouse Tumor Biology Database (MTB; http://tumor.informatics.jax.org) is designed to facilitate use of mouse models of human cancer by providing detailed histopathologic and molecular information on lymphoma subtypes, including expertly annotated, on line, whole slide scans, and providing a repository for storing information on and querying these data for specific lymphoma models. Copyright © 2015 Elsevier Inc. All rights reserved.

Mouse models rarely mimic the transcriptome of human neurodegenerative diseases: A systematic bioinformatics-based critique of preclinical models.

PubMed

Burns, Terry C; Li, Matthew D; Mehta, Swapnil; Awad, Ahmed J; Morgan, Alexander A

2015-07-15

Translational research for neurodegenerative disease depends intimately upon animal models. Unfortunately, promising therapies developed using mouse models mostly fail in clinical trials, highlighting uncertainty about how well mouse models mimic human neurodegenerative disease at the molecular level. We compared the transcriptional signature of neurodegeneration in mouse models of Alzheimer׳s disease (AD), Parkinson׳s disease (PD), Huntington׳s disease (HD) and amyotrophic lateral sclerosis (ALS) to human disease. In contrast to aging, which demonstrated a conserved transcriptome between humans and mice, only 3 of 19 animal models showed significant enrichment for gene sets comprising the most dysregulated up- and down-regulated human genes. Spearman׳s correlation analysis revealed even healthy human aging to be more closely related to human neurodegeneration than any mouse model of AD, PD, ALS or HD. Remarkably, mouse models frequently upregulated stress response genes that were consistently downregulated in human diseases. Among potential alternate models of neurodegeneration, mouse prion disease outperformed all other disease-specific models. Even among the best available animal models, conserved differences between mouse and human transcriptomes were found across multiple animal model versus human disease comparisons, surprisingly, even including aging. Relative to mouse models, mouse disease signatures demonstrated consistent trends toward preserved mitochondrial function protein catabolism, DNA repair responses, and chromatin maintenance. These findings suggest a more complex and multifactorial pathophysiology in human neurodegeneration than is captured through standard animal models, and suggest that even among conserved physiological processes such as aging, mice are less prone to exhibit neurodegeneration-like changes. This work may help explain the poor track record of mouse-based translational therapies for neurodegeneration and provides a path forward to critically evaluate and improve animal models of human disease. Copyright © 2015 Elsevier B.V. All rights reserved.

A Quantitative Measure of Handgrip Myotonia in Non-dystrophic Myotonia

PubMed Central

Statland, Jeffrey M; Bundy, Brian N; Wang, Yunxia; Trivedi, Jaya R; Rayan, Dipa Raja; Herbelin, Laura; Donlan, Merideth; McLin, Rhonda; Eichinger, Katy J; Findlater, Karen; Dewar, Liz; Pandya, Shree; Martens, William B; Venance, Shannon L; Matthews, Emma; Amato, Anthony A; Hanna, Michael G; Griggs, Robert C; Barohn, Richard J

2012-01-01

Introduction Non-dystrophic Myotonia (NDM) is characterized by myotonia without muscle wasting. A standardized quantitative myotonia assessment (QMA) is important for clinical trials. Methods Myotonia was assessed in 91 individuals enrolled in a natural history study using a commercially available computerized handgrip myometer and automated software. Average peak force and 90% to 5% relaxation times were compared to historical normal controls studied with identical methods. Results 30 subjects had chloride channel mutations, 31 sodium channel mutations, 6 DM2, and 24 no identified mutation. Chloride channel mutations were associated with prolonged 1st handgrip relaxation times, and warm up on subsequent handgrips. Sodium channel mutations were associated with prolonged 1st handgrip relaxation times and paradoxical myotonia or warm-up, depending on underlying mutations. DM2 subjects had normal relaxation times but decreased peak force. Sample size estimates are provided for clinical trial planning. Conclusion QMA is an automated, non-invasive technique for evaluating myotonia in NDM. PMID:22987687

Asymptomatic myotonia congenita unmasked by severe hypothyroidism.

PubMed

Passeri, Elena; Sansone, Valeria A; Verdelli, Chiara; Mendola, Marco; Corbetta, Sabrina

2014-04-01

Myotonia congenita is an inherited muscle disorder sustained by mutations in the skeletal muscle chloride channel gene CLCN1. Symptoms vary from mild to severe and generalized myotonia and worsen with cold, stressful events and hormonal fluctuations. Here we report the case of a young woman who sought medical attention because of subacute onset of diffuse and severe limb myotonia. CLCN1 gene sequencing showed a heterozygous transversion (T550M), two polymorphisms and one silent mutation. Thyroid function screening revealed severe hypothyroidism. She was placed on l-thyroxine replacement therapy which dramatically improved myotonia. We conclude that hypothyroidism unmasked a genetically determined, clinically asymptomatic chloride channelopathy. Diagnostic work-up in patients with clinically isolated myotonia should not be limited to genetic screening of non-dystrophic or dystrophic myotonias. Considering the high prevalence of hypothyroidism in females, systematic thyroid function screening by looking for additional hypothyroid symptoms and serum TSH levels measurement is mandatory in these patients. Copyright © 2014 Elsevier B.V. All rights reserved.

In vivo treatment with the NF-κB inhibitor ursodeoxycholic acid (UDCA) improves tension development in the isolated mdx costal diaphragm.

PubMed

Carlson, C George; Potter, Ross; Yu, Vivien; Luo, Kevin; Lavin, Jesse; Nielsen, Cory

2016-03-01

Previous experiments have indicated that in vivo administration of ursodeoxycholic acid (UDCA) inhibits nuclear NF-κB activation and has beneficial effects on the structure and function of dystrophic (mdx) muscle. We examined the effect of UDCA on tension development in dystrophic muscle. Isometric tension development was examined in costal diaphragms that were freshly isolated from vehicle and UDCA treated mdx mice. Percent recovery scores were obtained by directly comparing these measurements to those obtained from age-matched nondystrophic mice. Vehicle treated mdx mice exhibited significantly reduced optimal muscle lengths (lo ) and specific twitch and tetanic tensions compared with age-matched nondystrophic mice. UDCA treated preparations exhibited significantly improved tension development with a 33% recovery score. Because UDCA is used in treating certain clinical disorders, these results provide a rationale for human clinical trials using this and related drugs for treatment of Duchenne and related muscular dystrophies. © 2015 Wiley Periodicals, Inc.

Biologic behavior of vulvar intraepithelial neoplasia. Histologic and clinical parameters.

PubMed

Barbero, M; Micheletti, L; Preti, M; Valentino, M C; Nicolaci, P; Canní, M; Ghiringhello, B; Borgno, G

1993-02-01

The aim of this study was to evaluate the role by which different factors, such as human papillomavirus (HPV) infection, age, dystrophic alterations, focal nature and size of the lesion, influence the biologic behavior of vulvar intraepithelial neoplasia (VIN). Sixty-nine cases of VIN were investigated (28 VIN 1, 9 VIN 2, 32 VIN 3). Follow-up was possible in 58 cases, with a mean of 31 months; no treatment was given to 3 patients, while 55 were treated either medically or surgically. Eighty-four percent of the patients were cured, recurrences were found in 11%, and 5% of the patients showed progression of the disease to carcinoma. The ratio between medical and surgical treatment was the same among the cured, recurred and progressed groups of patients. No differences with regard to focal nature of the lesion, presence of HPV infection or dystrophic alterations were observed between the three groups of patients. Only the mean age was higher in patients who showed progression of the lesion to carcinoma.

Effective regeneration of dystrophic muscle using autologous iPSC-derived progenitors with CRISPR-Cas9 mediated precise correction.

PubMed

Hagan, Mackenzie; Ashraf, Muhammad; Kim, Il-Man; Weintraub, Neal L; Tang, Yaoliang

2018-01-01

Duchenne muscular dystrophy (DMD) is a lethal muscle wasting disease caused by a lack of dystrophin, which eventually leads to apoptosis of muscle cells and impaired muscle contractility. Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated protein 9 (CRISPR/Cas9) gene editing of induced pluripotent stem cells (IPSC) offers the potential to correct the DMD gene defect and create healthy IPSC for autologous cell transplantation without causing immune activation. However, IPSC carry a risk of tumor formation, which can potentially be mitigated by differentiation of IPSC into myogenic progenitor cells (MPC). We hypothesize that precise genetic editing in IPSC using CRISPR-Cas9 technology, coupled with MPC differentiation and autologous transplantation, can lead to safe and effective muscle repair. With future research, our hypothesis may provide an optimal autologous stem cell-based approach to treat the dystrophic pathology and improve the quality of life for patients with DMD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Connective tissue cells expressing fibro/adipogenic progenitor markers increase under chronic damage: relevance in fibroblast-myofibroblast differentiation and skeletal muscle fibrosis.

PubMed

Contreras, Osvaldo; Rebolledo, Daniela L; Oyarzún, Juan Esteban; Olguín, Hugo C; Brandan, Enrique

2016-06-01

Fibrosis occurs in skeletal muscle under various pathophysiological conditions such as Duchenne muscular dystrophy (DMD), a devastating disease characterized by fiber degeneration that results in progressive loss of muscle mass, weakness and increased extracellular matrix (ECM) accumulation. Fibrosis is also observed after skeletal muscle denervation and repeated cycles of damage followed by regeneration. The ECM is synthesized largely by fibroblasts in the muscle connective tissue under normal conditions. Myofibroblasts, cells that express α-smooth muscle actin (α-SMA), play a role in many tissues affected by fibrosis. In skeletal muscle, fibro/adipogenic progenitors (FAPs) that express cell-surface platelet-derived growth factor receptor-α (PDGFR-α) and the transcription factor Tcf4 seem to be responsible for connective tissue synthesis and are good candidates for the origin of myofibroblasts. We show that cells positive for Tcf4 and PDGFR-α are expressed in skeletal muscle under normal conditions and are increased in various skeletal muscles of mdx mice, a murine model for DMD, wild type muscle after sciatic denervation and muscle subjected to chronic damage. These cells co-label with the myofibroblast marker α-SMA in dystrophic muscle but not in normal tissue. The Tcf4-positive cells lie near macrophages mainly concentrated in dystrophic necrotic-regenerating foci. The close proximity of Tcf4-positive cells to inflammatory cells and their previously described role in muscle regeneration might reflect an active interaction between these cell types and growth factors, possibly resulting in a muscular regenerative or fibrotic condition.

Flavocoxid counteracts muscle necrosis and improves functional properties in mdx mice: a comparison study with methylprednisolone.

PubMed

Messina, Sonia; Bitto, Alessandra; Aguennouz, M'hammed; Mazzeo, Anna; Migliorato, Alba; Polito, Francesca; Irrera, Natasha; Altavilla, Domenica; Vita, Gian Luca; Russo, Massimo; Naro, Antonino; De Pasquale, Maria Grazia; Rizzuto, Emanuele; Musarò, Antonio; Squadrito, Francesco; Vita, Giuseppe

2009-12-01

Muscle degeneration in dystrophic muscle is exacerbated by the endogenous inflammatory response and increased oxidative stress. A key role is played by nuclear factor(NF)-kappaB. We showed that NF-kappaB inhibition through compounds with also antioxidant properties has beneficial effects in mdx mice, the murine model of Duchenne muscular dystrophy (DMD), but these drugs are not available for clinical studies. We evaluated whether flavocoxid, a mixed flavonoid extract with anti-inflammatory, antioxidant and NF-kappaB inhibiting properties, has beneficial effects in mdx mice in comparison with methylprednisolone, the gold standard treatment for DMD patients. Five-week-old mdx mice were treated for 5 weeks with flavocoxid, methylprednisolone or vehicle. The evaluation of in vivo and ex vivo functional properties and morphological parameters was performed. Serum samples were assayed for oxidative stress markers, creatine-kinase (CK) and leukotriene B-4. Cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), tumor necrosis factor-alpha, p-38, JNK1 expression was evaluated in muscle by western blot analysis. NF-kappaB binding activity was investigated by electrophoresis mobility shift assay. The administration of flavocoxid: (1) ameliorated functional properties in vivo and ex vivo; (2) reduced CK; (3) reduced the expression of oxidative stress markers and of inflammatory mediators; (4) inhibited NF-kappaB and mitogen-activated protein kinases (MAPKs) signal pathways; (5) reduced muscle necrosis and enhanced regeneration. Our results highlight the detrimental effects of oxidative stress and NF-kappaB, MAPKs and COX/5-LOX pathways in the dystrophic process and show that flavocoxid is more effective in mdx mice than methylprednisolone.

Hierarchical accumulation of RyR post-translational modifications drives disease progression in dystrophic cardiomyopathy.

PubMed

Kyrychenko, Sergii; Poláková, Eva; Kang, Chifei; Pocsai, Krisztina; Ullrich, Nina D; Niggli, Ernst; Shirokova, Natalia

2013-03-15

Duchenne muscular dystrophy (DMD) is a muscle disease with serious cardiac complications. Changes in Ca(2+) homeostasis and oxidative stress were recently associated with cardiac deterioration, but the cellular pathophysiological mechanisms remain elusive. We investigated whether the activity of ryanodine receptor (RyR) Ca(2+) release channels is affected, whether changes in function are cause or consequence and which post-translational modifications drive disease progression. Electrophysiological, imaging, and biochemical techniques were used to study RyRs in cardiomyocytes from mdx mice, an animal model of DMD. Young mdx mice show no changes in cardiac performance, but do so after ∼8 months. Nevertheless, myocytes from mdx pups exhibited exaggerated Ca(2+) responses to mechanical stress and 'hypersensitive' excitation-contraction coupling, hallmarks of increased RyR Ca(2+) sensitivity. Both were normalized by antioxidants, inhibitors of NAD(P)H oxidase and CaMKII, but not by NO synthases and PKA antagonists. Sarcoplasmic reticulum Ca(2+) load and leak were unchanged in young mdx mice. However, by the age of 4-5 months and in senescence, leak was increased and load was reduced, indicating disease progression. By this age, all pharmacological interventions listed above normalized Ca(2+) signals and corrected changes in ECC, Ca(2+) load, and leak. Our findings suggest that increased RyR Ca(2+) sensitivity precedes and presumably drives the progression of dystrophic cardiomyopathy, with oxidative stress initiating its development. RyR oxidation followed by phosphorylation, first by CaMKII and later by PKA, synergistically contributes to cardiac deterioration.

Systemic Delivery of Morpholinos to Skip Multiple Exons in a Dog Model of Duchenne Muscular Dystrophy.

PubMed

Maruyama, Rika; Echigoya, Yusuke; Caluseriu, Oana; Aoki, Yoshitsugu; Takeda, Shin'ichi; Yokota, Toshifumi

2017-01-01

Exon-skipping therapy is an emerging approach that uses synthetic DNA-like molecules called antisense oligonucleotides (AONs) to splice out frame-disrupting parts of mRNA, restore the reading frame, and produce truncated yet functional proteins. Multiple exon skipping utilizing a cocktail of AONs can theoretically treat 80-90% of patients with Duchenne muscular dystrophy (DMD). The success of multiple exon skipping by the systemic delivery of a cocktail of AONs called phosphorodiamidate morpholino oligomers (PMOs) in a DMD dog model has made a significant impact on the development of therapeutics for DMD, leading to clinical trials of PMO-based drugs. Here, we describe the systemic delivery of a cocktail of PMOs to skip multiple exons in dystrophic dogs and the evaluation of the efficacies and toxicity in vivo.

Some Dynamics of Personality Development in Boys Suffering from Muscular Dystrophy

ERIC Educational Resources Information Center

Mearig, Judith S.

1973-01-01

Discussed are personality aspects of Duchenne or pseudohypertrophic muscular dystrophy, a progressive wasting of muscular tissue, which afflicts only boys, and usually has its noticeable onset before the age of 6 years; and described is the development of three male dystrophic siblings. (DB)

Implications of Protein Alkylation and Proteolysis on Vesication Caused by Sulfur Mustard.

DTIC Science & Technology

1998-10-01

the integrity of the basement membrane is destroyed, such as dermatitis herpetiformis, dystrophic epidermolysis bullosa and lichen planus (Kähäri...A., Schiraldi, O., and Quaranta, V. (1996). Altered expression of basement membrane proteins and their integrin receptors in lichen planus : possible

Basal membrane complex architecture is disrupted during posterior subcapsular cataract formation in Royal College of Surgeons rats

PubMed Central

Joy, Anita

2014-01-01

Purpose Previous studies detailing the development of posterior subcapsular cataracts (PSC) in Royal College of Surgeons (RCS) rats have shown that aberrant fiber-end migration underlies the structural compromise. This investigation was conducted to examine the distribution of select basal membrane complex (BMC) components and to assess the intravitreal levels of specific cytokines during PSC formation. Methods Lenses from 52 RCS dystrophic rats (RCS/Lav) and 28 genetically matched control animals (RCS-rdy+/Lav) from 2 to 8 weeks old were used. After enucleation, vitreous was collected for eventual cytokine level analyses; lenses were then removed and processed for immunocytochemical localization of actin, cadherin, β integrin, vinculin, and cell nuclei. Results At 2–3 weeks postnatal, dystrophic lenses showed normal BMC distribution of actin, cadherin, and vinculin; however β integrin distribution was altered as compared to controls. By 4–6 weeks of age, F-actin was visible as bright foci arranged in a “rosette” pattern around fiber-end profiles. Concurrently, vinculin was rearranged into a diffuse pattern within the BMC. Cadherin delineated the fiber ends in dystrophic lenses until 5 weeks postnatal, after which it displayed diffuse cytoplasmic staining with more definitive labeling at the BMC periphery. β integrin was initially distributed as punctuate spots at 2–3 weeks postnatal; however, by 4–6 weeks it was co-localized with F-actin around the periphery of fiber ends. The distribution of F-actin, cadherin, and β integrin components did not undergo further changes after 6 weeks of age; however, vinculin was present predominantly at the periphery of the BMC in 7–8-week-old dystrophic lenses. Intravitreal cytokine levels were assessed for interleukin (IL)-1α, IL-4, IL-6, IL-8, tumor necrosis factor (TNF), and interferon (IFN)-γ. Levels of IL-1α, IL-4, TNF, and IFN-γ demonstrated a similar pattern, with concentrations increasing from 2 to 6 weeks postnatal and then decreasing slightly up to 8 weeks of age. IL-4 and TNF had the highest average concentrations, with peaks of 148.00 pg/ml and 34.20 pg/ml, respectively. Conclusions The data indicate that defined rearrangements of normal BMC architecture precede and characterize the structural changes that culminate in the PSC. These are consistent with modifications of adhesion mechanics involving cell–cell attachment, cell–matrix adhesion, and timely fiber-end detachment. Further, the results suggest that pro-inflammatory cytokines are potential initiating factors in aberrant fiber-end migration and subsequent PSC formation. PMID:25593506

System parameters for erythropoiesis control model: Comparison of normal values in human and mouse model

NASA Technical Reports Server (NTRS)

1979-01-01

The computer model for erythropoietic control was adapted to the mouse system by altering system parameters originally given for the human to those which more realistically represent the mouse. Parameter values were obtained from a variety of literature sources. Using the mouse model, the mouse was studied as a potential experimental model for spaceflight. Simulation studies of dehydration and hypoxia were performed. A comparison of system parameters for the mouse and human models is presented. Aside from the obvious differences expected in fluid volumes, blood flows and metabolic rates, larger differences were observed in the following: erythrocyte life span, erythropoietin half-life, and normal arterial pO2.

Human mammary microenvironment better regulates the biology of human breast cancer in humanized mouse model.

PubMed

Zheng, Ming-Jie; Wang, Jue; Xu, Lu; Zha, Xiao-Ming; Zhao, Yi; Ling, Li-Jun; Wang, Shui

2015-02-01

During the past decades, many efforts have been made in mimicking the clinical progress of human cancer in mouse models. Previously, we developed a human breast tissue-derived (HB) mouse model. Theoretically, it may mimic the interactions between "species-specific" mammary microenvironment of human origin and human breast cancer cells. However, detailed evidences are absent. The present study (in vivo, cellular, and molecular experiments) was designed to explore the regulatory role of human mammary microenvironment in the progress of human breast cancer cells. Subcutaneous (SUB), mammary fat pad (MFP), and HB mouse models were developed for in vivo comparisons. Then, the orthotopic tumor masses from three different mouse models were collected for primary culture. Finally, the biology of primary cultured human breast cancer cells was compared by cellular and molecular experiments. Results of in vivo mouse models indicated that human breast cancer cells grew better in human mammary microenvironment. Cellular and molecular experiments confirmed that primary cultured human breast cancer cells from HB mouse model showed a better proliferative and anti-apoptotic biology than those from SUB to MFP mouse models. Meanwhile, primary cultured human breast cancer cells from HB mouse model also obtained the migratory and invasive biology for "species-specific" tissue metastasis to human tissues. Comprehensive analyses suggest that "species-specific" mammary microenvironment of human origin better regulates the biology of human breast cancer cells in our humanized mouse model of breast cancer, which is more consistent with the clinical progress of human breast cancer.

Second-generation compound for the modulation of utrophin in the therapy of DMD

PubMed Central

Guiraud, Simon; Squire, Sarah E.; Edwards, Benjamin; Chen, Huijia; Burns, David T.; Shah, Nandini; Babbs, Arran; Davies, Stephen G.; Wynne, Graham M.; Russell, Angela J.; Elsey, David; Wilson, Francis X.; Tinsley, Jon M.; Davies, Kay E.

2015-01-01

Duchenne muscular dystrophy (DMD) is a lethal, X-linked muscle-wasting disease caused by lack of the cytoskeletal protein dystrophin. There is currently no cure for DMD although various promising approaches are progressing through human clinical trials. By pharmacologically modulating the expression of the dystrophin-related protein utrophin, we have previously demonstrated in dystrophin-deficient mdx studies, daily SMT C1100 treatment significantly reduced muscle degeneration leading to improved muscle function. This manuscript describes the significant disease modifying benefits associated with daily dosing of SMT022357, a second-generation compound in this drug series with improved physicochemical properties and a more robust metabolism profile. These studies in the mdx mouse demonstrate that oral administration of SMT022357 leads to increased utrophin expression in skeletal, respiratory and cardiac muscles. Significantly, utrophin expression is localized along the length of the muscle fibre, not just at the synapse, and is fibre-type independent, suggesting that drug treatment is modulating utrophin transcription in extra-synaptic myonuclei. This results in improved sarcolemmal stability and prevents dystrophic pathology through a significant reduction of regeneration, necrosis and fibrosis. All these improvements combine to protect the mdx muscle from contraction induced damage and enhance physiological function. This detailed evaluation of the SMT C1100 drug series strongly endorses the therapeutic potential of utrophin modulation as a disease modifying therapeutic strategy for all DMD patients irrespective of their dystrophin mutation. PMID:25935002

The Mouse Tumor Biology Database: A Comprehensive Resource for Mouse Models of Human Cancer.

PubMed

Krupke, Debra M; Begley, Dale A; Sundberg, John P; Richardson, Joel E; Neuhauser, Steven B; Bult, Carol J

2017-11-01

Research using laboratory mice has led to fundamental insights into the molecular genetic processes that govern cancer initiation, progression, and treatment response. Although thousands of scientific articles have been published about mouse models of human cancer, collating information and data for a specific model is hampered by the fact that many authors do not adhere to existing annotation standards when describing models. The interpretation of experimental results in mouse models can also be confounded when researchers do not factor in the effect of genetic background on tumor biology. The Mouse Tumor Biology (MTB) database is an expertly curated, comprehensive compendium of mouse models of human cancer. Through the enforcement of nomenclature and related annotation standards, MTB supports aggregation of data about a cancer model from diverse sources and assessment of how genetic background of a mouse strain influences the biological properties of a specific tumor type and model utility. Cancer Res; 77(21); e67-70. ©2017 AACR . ©2017 American Association for Cancer Research.

Axillary Brachial Plexus Blockade for the Reflex Sympathetic Dystrophy Syndrome.

ERIC Educational Resources Information Center

Ribbers, G. M.; Geurts, A. C. H.; Rijken, R. A. J.; Kerkkamp, H. E. M.

1997-01-01

Reflex sympathetic dystrophy syndrome (RSD) is a neurogenic pain syndrome characterized by pain, vasomotor and dystrophic changes, and often motor impairments. This study evaluated the effectiveness of brachial plexus blockade with local anaesthetic drugs as a treatment for this condition. Three patients responded well; three did not. (DB)

Development of rabbit monoclonal antibodies for detection of alpha-dystroglycan in normal and dystrophic tissue

USDA-ARS?s Scientific Manuscript database

Alpha-dystroglycan requires a rare O-mannose glycan modification to form its binding epitope for extracellular matrix proteins such as laminin. This functional glycan is disrupted in a cohort of muscular dystrophies, the secondary dystroglycanopathies, and is abnormal in some metastatic cancers. The...

[Clinical application of three-dimensional O-arm navigation system in treating patients with dystrophic scoliosis secondary to neurofibromatosis type Ⅰ].

PubMed

Liu, Z; Qiu, Y; Li, Y; Zhao, Z H; Wang, B; Zhu, F; Yu, Y; Sun, X; Zhu, Z Z

2017-03-01

Objective: To investigate the clinical outcomes and the accuracy of O-arm-navigation system assisted pedicle screw insertion in dystrophic scoliosis secondary to neurofibromatosis type Ⅰ(NF-1). Methods: A retrospective study was conducted in 41 patients with dystrophic NF-1-associated thoracic scoliosis who were surgically treated at Department of Orthopaedics, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School between June 2012 and October 2014 with more than 18 months follow-up. The patients were then divided into two groups: 18 patients were under the assistance of O-arm-navigation-based pedicle screw insertion (O-arm group) and the remaining 23 patients' pedicle screws insertion were conducted by free-hand (free-hand group). The X-ray and CT were analyzed to investigate the correction rate and safety of pedicle insertion. t -test was used to analyze measurement data and χ(2) test was used to analyze accuracy of screw insertion between the two groups. Results: The mean coronal Cobb angle was 63.2°±8.7° in the O-arm group and 66.9°±7.4° in the free-hand group ( P >0.05), which was then corrected into 23.1°±6.8° and 30.2°±7.6°( t =2.231, P =0.031) after surgery respectively.Operation time was (265.0±70.3)minutes and estimated blood loss was (1 024±465)ml in the O-arm group. Operation time and estimated blood loss was (243.0±49.6)minutes and (1 228±521)ml respectively in the free-hand group, which had no significant difference between the two groups. However, the implant density was higher in the O-arm group than that in the free-hand group ((64.1±10.8)% vs .(44.3±15.3)%)( t =4.652, P =0.000). The O-arm group comprised 122 screws, of which 72.9% were excellent, 22.1% were good and 4.9% were bad. The free-hand group comprised 136 screws and 48.5% of them were excellent, 33.8% were good and 17.6% were bad.Accuracy of pedicle screw insertion was higher in the O-arm group than that in the free-hand group(χ(2)=10.140, P <0.05). By June 2016, the average follow-up period was (20.9±3.4)months(ranging from18 to 26 months), including (20.3±3.1)months in the O-arm group and (21.4±5.5)months in the free-hand group. At last follow-up point, coronal correction loss was significantly higher in the free-hand group than that in the O-arm group (6.3°±2.6° vs . 4.4°±1.6°)( t =2.719, P =0.009). Conclusions: Compared with free-hand technique, O-arm-navigation technique could enhance accuracy of pedicle insertion and implant density of dystrophic region in dystrophic NF-1-associated scoliosis patients, which result in a better correction rate and less correction loss. Besides, the advantage of O-arm-navigation do not increase operative time and estimate blood loss.

Drug discovery in prostate cancer mouse models.

PubMed

Valkenburg, Kenneth C; Pienta, Kenneth J

2015-01-01

The mouse is an important, though imperfect, organism with which to model human disease and to discover and test novel drugs in a preclinical setting. Many experimental strategies have been used to discover new biological and molecular targets in the mouse, with the hopes of translating these discoveries into novel drugs to treat prostate cancer in humans. Modeling prostate cancer in the mouse, however, has been challenging, and often drugs that work in mice have failed in human trials. The authors discuss the similarities and differences between mice and men; the types of mouse models that exist to model prostate cancer; practical questions one must ask when using a mouse as a model; and potential reasons that drugs do not often translate to humans. They also discuss the current value in using mouse models for drug discovery to treat prostate cancer and what needs are still unmet in field. With proper planning and following practical guidelines by the researcher, the mouse is a powerful experimental tool. The field lacks genetically engineered metastatic models, and xenograft models do not allow for the study of the immune system during the metastatic process. There remain several important limitations to discovering and testing novel drugs in mice for eventual human use, but these can often be overcome. Overall, mouse modeling is an essential part of prostate cancer research and drug discovery. Emerging technologies and better and ever-increasing forms of communication are moving the field in a hopeful direction.

Orthology for comparative genomics in the mouse genome database.

PubMed

Dolan, Mary E; Baldarelli, Richard M; Bello, Susan M; Ni, Li; McAndrews, Monica S; Bult, Carol J; Kadin, James A; Richardson, Joel E; Ringwald, Martin; Eppig, Janan T; Blake, Judith A

2015-08-01

The mouse genome database (MGD) is the model organism database component of the mouse genome informatics system at The Jackson Laboratory. MGD is the international data resource for the laboratory mouse and facilitates the use of mice in the study of human health and disease. Since its beginnings, MGD has included comparative genomics data with a particular focus on human-mouse orthology, an essential component of the use of mouse as a model organism. Over the past 25 years, novel algorithms and addition of orthologs from other model organisms have enriched comparative genomics in MGD data, extending the use of orthology data to support the laboratory mouse as a model of human biology. Here, we describe current comparative data in MGD and review the history and refinement of orthology representation in this resource.

[Current status and future prospects of research on Fukuyama muscular dystrophy].

PubMed

Toda, Tatsushi

2015-08-01

Fukuyama congenital muscular dystrophy(FCMD) is a second common childhood muscular dystrophy in Japan. All FCMD patients have ancestral insertion of the SVA retrotransposal element into fukutin. We show that aberrant mRNA splicing induced by SVA exon-trapping caused FCMD. Introduction of 3 cocktailed antisense oligonucleotides(AONs) targeting around these splice sites prevented pathogenic splicing in FCMD patient cells and model mice, and normalized protein production and functions of Fukutin as well as O-glycosylation of α-dystroglycan. We show the promise of splicing modulation therapy as the first radical clinical treatment for FCMD in the near future. We also show that fukutin is prerequisite to ameliorate muscular dystrophic phenotype by myofiber-selective LARGE expression. Recent advances in FCMD are discussed.

Genetically Engineered Mouse Models for Studying Inflammatory Bowel Disease

PubMed Central

Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

2015-01-01

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. PMID:26387641

Change in the intraorganic nerve apparatuses of muscles under conditions of the combined action of a dc magnetic field and acceleration

NASA Technical Reports Server (NTRS)

Govev, V. P.; Chepelenko, G. V.

1975-01-01

Damage to neurons in the rat when the animals are subjected to a constant magnetic field is a function of their reactive capacity. The reactive stage is characterized by dystrophic changes without any definite signs of destruction of tissue.

Osteopontin ablation ameliorates muscular dystrophy by shifting macrophages to a pro-regenerative phenotype

PubMed Central

Capote, Joana; Martinez, Leonel; Vetrone, Sylvia; Barton, Elisabeth R.; Sweeney, H. Lee; Miceli, M. Carrie

2016-01-01

In the degenerative disease Duchenne muscular dystrophy, inflammatory cells enter muscles in response to repetitive muscle damage. Immune factors are required for muscle regeneration, but chronic inflammation creates a profibrotic milieu that exacerbates disease progression. Osteopontin (OPN) is an immunomodulator highly expressed in dystrophic muscles. Ablation of OPN correlates with reduced fibrosis and improved muscle strength as well as reduced natural killer T (NKT) cell counts. Here, we demonstrate that the improved dystrophic phenotype observed with OPN ablation does not result from reductions in NKT cells. OPN ablation skews macrophage polarization toward a pro-regenerative phenotype by reducing M1 and M2a and increasing M2c subsets. These changes are associated with increased expression of pro-regenerative factors insulin-like growth factor 1, leukemia inhibitory factor, and urokinase-type plasminogen activator. Furthermore, altered macrophage polarization correlated with increases in muscle weight and muscle fiber diameter, resulting in long-term improvements in muscle strength and function in mdx mice. These findings suggest that OPN ablation promotes muscle repair via macrophage secretion of pro-myogenic growth factors. PMID:27091452

Amyloid and intracellular accumulation of BRI2.

PubMed

Garringer, Holly J; Sammeta, Neeraja; Oblak, Adrian; Ghetti, Bernardino; Vidal, Ruben

2017-04-01

Familial British dementia (FBD) and familial Danish dementia (FDD) are caused by mutations in the BRI 2 gene. These diseases are characterized clinically by progressive dementia and ataxia and neuropathologically by amyloid deposits and neurofibrillary tangles. Herein, we investigate BRI 2 protein accumulation in FBD, FDD, Alzheimer disease and Gerstmann-Sträussler-Scheinker disease. In FBD and FDD, we observed reduced processing of the mutant BRI 2 pro-protein, which was found accumulating intracellularly in the Golgi of neurons and glial cells. In addition, we observed an accumulation of a mature form of BRI 2 protein in dystrophic neurites, surrounding amyloid cores. Accumulation of BRI 2 was also observed in dystrophic neurites of Alzheimer disease and Gerstmann-Sträussler-Scheinker disease cases. Although it remains to be determined whether intracellular accumulation of BRI 2 may lead to cell damage in these degenerative diseases, our study provides new insights into the role of mutant BRI 2 in the pathogenesis of FBD and FDD and implicates BRI 2 as a potential indicator of neuritic damage in diseases characterized by cerebral amyloid deposition. Copyright © 2016 Elsevier Inc. All rights reserved.

Amyloid and intracellular accumulation of BRI2

PubMed Central

Garringer, Holly J.; Sammeta, Neeraja; Oblak, Adrian; Ghetti, Bernardino; Vidal, Ruben

2016-01-01

Familial British dementia (FBD) and familial Danish dementia (FDD) are caused by mutations in the BRI2 gene. These diseases are characterized clinically by progressive dementia and ataxia and neuropathologically by amyloid deposits and neurofibrillary tangles. Herein, we investigate BRI2 protein accumulation in FBD, FDD, Alzheimer disease and Gerstmann-Sträussler-Scheinker disease. In FBD and FDD, we observed reduced processing of the mutant BRI2 pro-protein, which was found accumulating intracellularly in the Golgi of neurons and glial cells. In addition, we observed an accumulation of a mature form of BRI2 protein in dystrophic neurites, surrounding amyloid cores. Accumulation of BRI2 was also observed in dystrophic neurites of Alzheimer disease and Gerstmann-Sträussler-Scheinker disease cases. Although it remains to be determined whether intracellular accumulation of BRI2 may lead to cell damage in these degenerative diseases, our study provides new insights into the role of mutant BRI2 in the pathogenesis of FBD and FDD and implicates BRI2 as a potential indicator of neuritic damage in diseases characterized by cerebral amyloid deposition. PMID:28131015

Losartan ameliorates dystrophic epidermolysis bullosa and uncovers new disease mechanisms

PubMed Central

Nyström, Alexander; Thriene, Kerstin; Mittapalli, Venugopal; Kern, Johannes S; Kiritsi, Dimitra; Dengjel, Jörn; Bruckner-Tuderman, Leena

2015-01-01

Genetic loss of collagen VII causes recessive dystrophic epidermolysis bullosa (RDEB)—a severe skin fragility disorder associated with lifelong blistering and disabling progressive soft tissue fibrosis. Causative therapies for this complex disorder face major hurdles, and clinical implementation remains elusive. Here, we report an alternative evidence-based approach to ameliorate fibrosis and relieve symptoms in RDEB. Based on the findings that TGF-β activity is elevated in injured RDEB skin, we targeted TGF-β activity with losartan in a preclinical setting. Long-term treatment of RDEB mice efficiently reduced TGF-β signaling in chronically injured forepaws and halted fibrosis and subsequent fusion of the digits. In addition, proteomics analysis of losartan- vs. vehicle-treated RDEB skin uncovered changes in multiple proteins related to tissue inflammation. In line with this, losartan reduced inflammation and diminished TNF-α and IL-6 expression in injured forepaws. Collectively, the data argue that RDEB fibrosis is a consequence of a cascade encompassing tissue damage, TGF-β-mediated inflammation, and matrix remodeling. Inhibition of TGF-β activity limits these unwanted outcomes and thereby substantially ameliorates long-term symptoms. PMID:26194911

Electrical Stimuli Are Anti-Apoptotic in Skeletal Muscle via Extracellular ATP. Alteration of This Signal in Mdx Mice Is a Likely Cause of Dystrophy

PubMed Central

Valladares, Denisse; Almarza, Gonzalo; Contreras, Ariel; Pavez, Mario; Buvinic, Sonja; Jaimovich, Enrique; Casas, Mariana

2013-01-01

ATP signaling has been shown to regulate gene expression in skeletal muscle and to be altered in models of muscular dystrophy. We have previously shown that in normal muscle fibers, ATP released through Pannexin1 (Panx1) channels after electrical stimulation plays a role in activating some signaling pathways related to gene expression. We searched for a possible role of ATP signaling in the dystrophy phenotype. We used muscle fibers from flexor digitorum brevis isolated from normal and mdx mice. We demonstrated that low frequency electrical stimulation has an anti-apoptotic effect in normal muscle fibers repressing the expression of Bax, Bim and PUMA. Addition of exogenous ATP to the medium has a similar effect. In dystrophic fibers, the basal levels of extracellular ATP were higher compared to normal fibers, but unlike control fibers, they do not present any ATP release after low frequency electrical stimulation, suggesting an uncoupling between electrical stimulation and ATP release in this condition. Elevated levels of Panx1 and decreased levels of Cav1.1 (dihydropyridine receptors) were found in triads fractions prepared from mdx muscles. Moreover, decreased immunoprecipitation of Cav1.1 and Panx1, suggest uncoupling of the signaling machinery. Importantly, in dystrophic fibers, exogenous ATP was pro-apoptotic, inducing the transcription of Bax, Bim and PUMA and increasing the levels of activated Bax and cytosolic cytochrome c. These evidence points to an involvement of the ATP pathway in the activation of mechanisms related with cell death in muscular dystrophy, opening new perspectives towards possible targets for pharmacological therapies. PMID:24282497

Electrical stimuli are anti-apoptotic in skeletal muscle via extracellular ATP. Alteration of this signal in Mdx mice is a likely cause of dystrophy.

PubMed

Valladares, Denisse; Almarza, Gonzalo; Contreras, Ariel; Pavez, Mario; Buvinic, Sonja; Jaimovich, Enrique; Casas, Mariana

2013-01-01

ATP signaling has been shown to regulate gene expression in skeletal muscle and to be altered in models of muscular dystrophy. We have previously shown that in normal muscle fibers, ATP released through Pannexin1 (Panx1) channels after electrical stimulation plays a role in activating some signaling pathways related to gene expression. We searched for a possible role of ATP signaling in the dystrophy phenotype. We used muscle fibers from flexor digitorum brevis isolated from normal and mdx mice. We demonstrated that low frequency electrical stimulation has an anti-apoptotic effect in normal muscle fibers repressing the expression of Bax, Bim and PUMA. Addition of exogenous ATP to the medium has a similar effect. In dystrophic fibers, the basal levels of extracellular ATP were higher compared to normal fibers, but unlike control fibers, they do not present any ATP release after low frequency electrical stimulation, suggesting an uncoupling between electrical stimulation and ATP release in this condition. Elevated levels of Panx1 and decreased levels of Cav1.1 (dihydropyridine receptors) were found in triads fractions prepared from mdx muscles. Moreover, decreased immunoprecipitation of Cav1.1 and Panx1, suggest uncoupling of the signaling machinery. Importantly, in dystrophic fibers, exogenous ATP was pro-apoptotic, inducing the transcription of Bax, Bim and PUMA and increasing the levels of activated Bax and cytosolic cytochrome c. These evidence points to an involvement of the ATP pathway in the activation of mechanisms related with cell death in muscular dystrophy, opening new perspectives towards possible targets for pharmacological therapies.

Combined N-of-1 trials to investigate mexiletine in non-dystrophic myotonia using a Bayesian approach; study rationale and protocol.

PubMed

Stunnenberg, Bas C; Woertman, Willem; Raaphorst, Joost; Statland, Jeffrey M; Griggs, Robert C; Timmermans, Janneke; Saris, Christiaan G; Schouwenberg, Bas J; Groenewoud, Hans M; Stegeman, Dick F; van Engelen, Baziel G M; Drost, Gea; van der Wilt, Gert Jan

2015-03-25

To obtain evidence for the clinical and cost-effectiveness of treatments for patients with rare diseases is a challenge. Non-dystrophic myotonia (NDM) is a group of inherited, rare muscle diseases characterized by muscle stiffness. The reimbursement of mexiletine, the expert opinion drug for NDM, has been discontinued in some countries due to a lack of independent randomized controlled trials (RCTs). It remains unclear however, which concessions can be accepted towards the level 1 evidence needed for coverage decisions, in rare diseases. Considering the large number of rare diseases with a lack of treatment evidence, more experience with innovative trial designs is needed. Both NDM and mexiletine are well suited for an N-of-1 trial design. A Bayesian approach allows for the combination of N-of-1 trials, which enables the assessment of outcomes on the patient and group level simultaneously. We will combine 30 individual, double-blind, randomized, placebo-controlled N-of-1 trials of mexiletine (600 mg daily) vs. placebo in genetically confirmed NDM patients using hierarchical Bayesian modeling. Our results will be compared and combined with the main results of an international cross-over RCT (mexiletine vs. placebo in NDM) published in 2012 that will be used as an informative prior. Similar criteria of eligibility, treatment regimen, end-points and measurement instruments are employed as used in the international cross-over RCT. The treatment of patients with NDM with mexiletine offers a unique opportunity to compare outcomes and efficiency of novel N-of-1 trial-based designs and conventional approaches in producing evidence of clinical and cost-effectiveness of treatments for patients with rare diseases. ClinicalTrials.gov Identifier: NCT02045667.

Alterations in NMDA receptor expression during retinal degeneration in the RCS rat.

PubMed

Gründer, T; Kohler, K; Guenther, E

2001-01-01

To determine how a progressive loss of photoreceptor cells and the concomitant loss of glutamatergic input to second-order neurons can affect inner-retinal signaling, glutamate receptor expression was analyzed in the Royal College of Surgeons (RCS) rat, an animal model of retinitis pigmentosa. Immunohistochemistry was performed on retinal sections of RCS rats and congenic controls between postnatal (P) day 3 and the aged adult (up to P350) using specific antibodies against N-methyl-D-aspartate (NMDA) subunits. All NMDA subunits (NR1, NR2A-2D) were expressed in control and dystrophic retinas at all ages, and distinct patterns of labeling were found in horizontal cells, subpopulations of amacrine cells and ganglion cells, as well as in the outer and inner plexiform layer (IPL). NRI immunoreactivity in the inner plexiform layer of adult control retinas was concentrated in two distinct bands, indicating a synaptic localization of NMDA receptors in the OFF and ON signal pathways. In the RCS retina, these bands of NRI immunoreactivity in the IPL were much weaker in animals older than P40. In parallel, NR2B immunoreactivity in the outer plexiform layer (OPL) of RCS rats was always reduced compared to controls and vanished between P40 and P120. The most striking alteration observed in the degenerating retina, however, was a strong expression of NRI immunoreactivity in Müller cell processes in the inner retina which was not observed in control animals and which was present prior to any visible sign of photoreceptor degeneration. The results suggest functional changes in glutamatergic receptor signaling in the dystrophic retina and a possible involvement of Müller cells in early processes of this disease.

Involvement of TRPV2 and SOCE in calcium influx disorder in DMD primary human myotubes with a specific contribution of α1-syntrophin and PLC/PKC in SOCE regulation.

PubMed

Harisseh, Rania; Chatelier, Aurélien; Magaud, Christophe; Déliot, Nadine; Constantin, Bruno

2013-05-01

Calcium homeostasis is critical for several vital functions in excitable and nonexcitable cells and has been shown to be impaired in many pathologies including Duchenne muscular dystrophy (DMD). Various studies using murine models showed the implication of calcium entry in the dystrophic phenotype. However, alteration of store-operated calcium entry (SOCE) and transient receptor potential vanilloid 2 (TRPV2)-dependant cation entry has not been investigated yet in human skeletal muscle cells. We pharmacologically characterized basal and store-operated cation entries in primary cultures of myotubes prepared from muscle of normal and DMD patients and found, for the first time, an increased SOCE in DMD myotubes. Moreover, this increase cannot be explained by an over expression of the well-known SOCE actors: TRPC1/4, Orai1, and stromal interaction molecule 1 (STIM1) mRNA and proteins. Thus we investigated the modes of regulation of this cation entry. We firstly demonstrated the important role of the scaffolding protein α1-syntrophin, which regulates SOCE in primary human myotubes through its PDZ domain. We also studied the implication of phospholipase C (PLC) and protein kinase C (PKC) in SOCE and showed that their inhibition restores normal levels of SOCE in DMD human myotubes. In addition, the involvement of TRPV2 in calcium deregulation in DMD human myotubes was explored. We showed an abnormal elevation of TRPV2-dependant cation entry in dystrophic primary human myotubes compared with normal ones. These findings show that calcium homeostasis mishandling in DMD myotubes depends on SOCE under the influence of Ca(2+)/PLC/PKC pathway and α1-syntrophin regulation as well as on TRPV2-dependant cation influx.

Genome-wide Mechanosensitive MicroRNA (MechanomiR) Screen Uncovers Dysregulation of Their Regulatory Networks in the mdm Mouse Model of Muscular Dystrophy.

PubMed

Mohamed, Junaith S; Hajira, Ameena; Lopez, Michael A; Boriek, Aladin M

2015-10-09

Muscular dystrophies (MDs) are a heterogeneous group of genetic and neuromuscular disorders, which result in severe loss of motor ability and skeletal muscle mass and function. Aberrant mechanotransduction and dysregulated-microRNA pathways are often associated with the progression of MD. Here, we hypothesized that dysregulation of mechanosensitive microRNAs (mechanomiRs) in dystrophic skeletal muscle plays a major role in the progression of MD. To test our hypothesis, we performed a genome-wide expression profile of anisotropically regulated mechanomiRs and bioinformatically analyzed their target gene networks. We assessed their functional roles in the advancement of MD using diaphragm muscles from mdm (MD with myositis) mice, an animal model of human tibial MD (titinopathy), and their wild-type littermates. We were able to show that ex vivo anisotropic mechanical stretch significantly alters the miRNA expression profile in diaphragm muscles from WT and mdm mice; as a result, some of the genes associated with MDs are dysregulated in mdm mice due to differential regulation of a distinct set of mechanomiRs. Interestingly, we found a contrasting expression pattern of the highly expressed let-7 family mechanomiRs, let-7e-5p and miR-98-5p, and their target genes associated with the extracellular matrix and TGF-β pathways, respectively, between WT and mdm mice. Gain- and loss-of-function analysis of let-7e-5p in myocytes isolated from the diaphragms of WT and mdm mice confirmed Col1a1, Col1a2, Col3a1, Col24a1, Col27a1, Itga1, Itga4, Scd1, and Thbs1 as target genes of let-7e-5p. Furthermore, we found that miR-98 negatively regulates myoblast differentiation. Our study therefore introduces additional biological players in the regulation of skeletal muscle structure and myogenesis that may contribute to unexplained disorders of MD. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Genome-wide expression profiling of five mouse models identifies similarities and differences with human psoriasis.

PubMed

Swindell, William R; Johnston, Andrew; Carbajal, Steve; Han, Gangwen; Wohn, Christian; Lu, Jun; Xing, Xianying; Nair, Rajan P; Voorhees, John J; Elder, James T; Wang, Xiao-Jing; Sano, Shigetoshi; Prens, Errol P; DiGiovanni, John; Pittelkow, Mark R; Ward, Nicole L; Gudjonsson, Johann E

2011-04-04

Development of a suitable mouse model would facilitate the investigation of pathomechanisms underlying human psoriasis and would also assist in development of therapeutic treatments. However, while many psoriasis mouse models have been proposed, no single model recapitulates all features of the human disease, and standardized validation criteria for psoriasis mouse models have not been widely applied. In this study, whole-genome transcriptional profiling is used to compare gene expression patterns manifested by human psoriatic skin lesions with those that occur in five psoriasis mouse models (K5-Tie2, imiquimod, K14-AREG, K5-Stat3C and K5-TGFbeta1). While the cutaneous gene expression profiles associated with each mouse phenotype exhibited statistically significant similarity to the expression profile of psoriasis in humans, each model displayed distinctive sets of similarities and differences in comparison to human psoriasis. For all five models, correspondence to the human disease was strong with respect to genes involved in epidermal development and keratinization. Immune and inflammation-associated gene expression, in contrast, was more variable between models as compared to the human disease. These findings support the value of all five models as research tools, each with identifiable areas of convergence to and divergence from the human disease. Additionally, the approach used in this paper provides an objective and quantitative method for evaluation of proposed mouse models of psoriasis, which can be strategically applied in future studies to score strengths of mouse phenotypes relative to specific aspects of human psoriasis.

Optimizing mouse models of neurodegenerative disorders: are therapeutics in sight?

PubMed

Lutz, Cathleen M; Osborne, Melissa A

2013-01-01

The genomic and biologic conservation between mice and humans, along with our increasing ability to manipulate the mouse genome, places the mouse as a premier model for deciphering disease mechanisms and testing potential new therapies. Despite these advantages, mouse models of neurodegenerative disease are sometimes difficult to generate and can present challenges that must be carefully addressed when used for preclinical studies. For those models that do exist, the standardization and optimization of the models is a critical step in ensuring success in both basic research and preclinical use. This review looks back on the history of model development for neurodegenerative diseases and highlights the key strategies that have been learned in order to improve the design, development and use of mouse models in the study of neurodegenerative disease.

The transition from linear to highly branched poly(β-amino ester)s: Branching matters for gene delivery

PubMed Central

Zhou, Dezhong; Cutlar, Lara; Gao, Yongsheng; Wang, Wei; O’Keeffe-Ahern, Jonathan; McMahon, Sean; Duarte, Blanca; Larcher, Fernando; Rodriguez, Brian J.; Greiser, Udo; Wang, Wenxin

2016-01-01

Nonviral gene therapy holds great promise but has not delivered treatments for clinical application to date. Lack of safe and efficient gene delivery vectors is the major hurdle. Among nonviral gene delivery vectors, poly(β-amino ester)s are one of the most versatile candidates because of their wide monomer availability, high polymer flexibility, and superior gene transfection performance both in vitro and in vivo. However, to date, all research has been focused on vectors with a linear structure. A well-accepted view is that dendritic or branched polymers have greater potential as gene delivery vectors because of their three-dimensional structure and multiple terminal groups. Nevertheless, to date, the synthesis of dendritic or branched polymers has been proven to be a well-known challenge. We report the design and synthesis of highly branched poly(β-amino ester)s (HPAEs) via a one-pot “A2 + B3 + C2”–type Michael addition approach and evaluate their potential as gene delivery vectors. We find that the branched structure can significantly enhance the transfection efficiency of poly(β-amino ester)s: Up to an 8521-fold enhancement in transfection efficiency was observed across 12 cell types ranging from cell lines, primary cells, to stem cells, over their corresponding linear poly(β-amino ester)s (LPAEs) and the commercial transfection reagents polyethyleneimine, SuperFect, and Lipofectamine 2000. Moreover, we further demonstrate that HPAEs can correct genetic defects in vivo using a recessive dystrophic epidermolysis bullosa graft mouse model. Our findings prove that the A2 + B3 + C2 approach is highly generalizable and flexible for the design and synthesis of HPAEs, which cannot be achieved by the conventional polymerization approach; HPAEs are more efficient vectors in gene transfection than the corresponding LPAEs. This provides valuable insight into the development and applications of nonviral gene delivery and demonstrates great prospect for their translation to a clinical environment. PMID:27386572

Store-operated channels regulate intracellular calcium in mammalian rods

PubMed Central

Molnar, Tünde; Barabas, Peter; Birnbaumer, Lutz; Punzo, Claudio; Kefalov, Vladimir; Križaj, David

2012-01-01

Exposure to daylight closes cyclic nucleotide-gated (CNG) and voltage-operated Ca2+-permeable channels in mammalian rods. The consequent lowering of the cytosolic calcium concentration ([Ca2+]i), if protracted, can contribute to light-induced damage and apoptosis in these cells. We here report that mouse rods are protected against prolonged lowering of [Ca2+]i by store-operated Ca2+ entry (SOCE). Ca2+ stores were depleted in Ca2+-free saline supplemented with the endoplasmic reticulum (ER) sequestration blocker cyclopiazonic acid. Store depletion elicited [Ca2+]i signals that exceeded baseline [Ca2+]i by 5.9 ± 0.7-fold and were antagonized by an inhibitory cocktail containing 2-APB, SKF 96365 and Gd3+. Cation influx through SOCE channels was sufficient to elicit a secondary activation of L-type voltage-operated Ca2+ entry. We also found that TRPC1, the type 1 canonical mammalian homologue of the Drosophila photoreceptor TRP channel, is predominantly expressed within the outer nuclear layer of the retina. Rod loss in Pde6brd1 (rd1), Chx10/Kip1−/−rd1 and Elovl4TG2 dystrophic models was associated with ∼70% reduction in Trpc1 mRNA content whereas Trpc1 mRNA levels in rodless cone-full Nrl−/− retinas were decreased by ∼50%. Genetic ablation of TRPC1 channels, however, had no effect on SOCE, the sensitivity of the rod phototransduction cascade or synaptic transmission at rod and cone synapses. Thus, we localized two new mechanisms, SOCE and TRPC1, to mammalian rods and characterized the contribution of SOCE to Ca2+ homeostasis. By preventing the cytosolic [Ca2+]i from dropping too low under sustained saturating light conditions, these signalling pathways may protect Ca2+-dependent mechanisms within the ER and the cytosol without affecting normal rod function. PMID:22674725

η-Secretase processing of APP inhibits neuronal activity in the hippocampus.

PubMed

Willem, Michael; Tahirovic, Sabina; Busche, Marc Aurel; Ovsepian, Saak V; Chafai, Magda; Kootar, Scherazad; Hornburg, Daniel; Evans, Lewis D B; Moore, Steven; Daria, Anna; Hampel, Heike; Müller, Veronika; Giudici, Camilla; Nuscher, Brigitte; Wenninger-Weinzierl, Andrea; Kremmer, Elisabeth; Heneka, Michael T; Thal, Dietmar R; Giedraitis, Vilmantas; Lannfelt, Lars; Müller, Ulrike; Livesey, Frederick J; Meissner, Felix; Herms, Jochen; Konnerth, Arthur; Marie, Hélène; Haass, Christian

2015-10-15

Alzheimer disease (AD) is characterized by the accumulation of amyloid plaques, which are predominantly composed of amyloid-β peptide. Two principal physiological pathways either prevent or promote amyloid-β generation from its precursor, β-amyloid precursor protein (APP), in a competitive manner. Although APP processing has been studied in great detail, unknown proteolytic events seem to hinder stoichiometric analyses of APP metabolism in vivo. Here we describe a new physiological APP processing pathway, which generates proteolytic fragments capable of inhibiting neuronal activity within the hippocampus. We identify higher molecular mass carboxy-terminal fragments (CTFs) of APP, termed CTF-η, in addition to the long-known CTF-α and CTF-β fragments generated by the α- and β-secretases ADAM10 (a disintegrin and metalloproteinase 10) and BACE1 (β-site APP cleaving enzyme 1), respectively. CTF-η generation is mediated in part by membrane-bound matrix metalloproteinases such as MT5-MMP, referred to as η-secretase activity. η-Secretase cleavage occurs primarily at amino acids 504-505 of APP695, releasing a truncated ectodomain. After shedding of this ectodomain, CTF-η is further processed by ADAM10 and BACE1 to release long and short Aη peptides (termed Aη-α and Aη-β). CTFs produced by η-secretase are enriched in dystrophic neurites in an AD mouse model and in human AD brains. Genetic and pharmacological inhibition of BACE1 activity results in robust accumulation of CTF-η and Aη-α. In mice treated with a potent BACE1 inhibitor, hippocampal long-term potentiation was reduced. Notably, when recombinant or synthetic Aη-α was applied on hippocampal slices ex vivo, long-term potentiation was lowered. Furthermore, in vivo single-cell two-photon calcium imaging showed that hippocampal neuronal activity was attenuated by Aη-α. These findings not only demonstrate a major functionally relevant APP processing pathway, but may also indicate potential translational relevance for therapeutic strategies targeting APP processing.

Applications and Limitations of Mouse Models for Understanding Human Atherosclerosis

PubMed Central

von Scheidt, Moritz; Zhao, Yuqi; Kurt, Zeyneb; Pan, Calvin; Zeng, Lingyao; Yang, Xia; Schunkert, Heribert; Lusis, Aldons J.

2017-01-01

Most of the biological understanding of mechanisms underlying coronary artery disease (CAD) derives from studies of mouse models. The identification of multiple CAD loci and strong candidate genes in large human genome-wide association studies (GWAS) presented an opportunity to examine the relevance of mouse models for the human disease. We comprehensively reviewed the mouse literature, including 827 literature-derived genes, and compared it to human data. First, we observed striking concordance of risk factors for atherosclerosis in mice and humans. Second, there was highly significant overlap of mouse genes with human genes identified by GWAS. In particular, of the 46 genes with strong association signals in CAD-GWAS that were studied in mouse models all but one exhibited consistent effects on atherosclerosis-related phenotypes. Third, we compared 178 CAD-associated pathways derived from human GWAS with 263 from mouse studies and observed that over 50% were consistent between both species. PMID:27916529

Genetically engineered mouse models for studying inflammatory bowel disease.

PubMed

Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

2016-01-01

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Mouse Tumor Biology (MTB): a database of mouse models for human cancer.

PubMed

Bult, Carol J; Krupke, Debra M; Begley, Dale A; Richardson, Joel E; Neuhauser, Steven B; Sundberg, John P; Eppig, Janan T

2015-01-01

The Mouse Tumor Biology (MTB; http://tumor.informatics.jax.org) database is a unique online compendium of mouse models for human cancer. MTB provides online access to expertly curated information on diverse mouse models for human cancer and interfaces for searching and visualizing data associated with these models. The information in MTB is designed to facilitate the selection of strains for cancer research and is a platform for mining data on tumor development and patterns of metastases. MTB curators acquire data through manual curation of peer-reviewed scientific literature and from direct submissions by researchers. Data in MTB are also obtained from other bioinformatics resources including PathBase, the Gene Expression Omnibus and ArrayExpress. Recent enhancements to MTB improve the association between mouse models and human genes commonly mutated in a variety of cancers as identified in large-scale cancer genomics studies, provide new interfaces for exploring regions of the mouse genome associated with cancer phenotypes and incorporate data and information related to Patient-Derived Xenograft models of human cancers. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

The latest animal models of ovarian cancer for novel drug discovery.

PubMed

Magnotti, Elizabeth; Marasco, Wayne A

2018-03-01

Epithelial ovarian cancer is a heterogeneous disease classified into five subtypes, each with a different molecular profile. Most cases of ovarian cancer are diagnosed after metastasis of the primary tumor and are resistant to traditional platinum-based chemotherapeutics. Mouse models of ovarian cancer have been utilized to discern ovarian cancer tumorigenesis and the tumor's response to therapeutics. Areas covered: The authors provide a review of mouse models currently employed to understand ovarian cancer. This article focuses on advances in the development of orthotopic and patient-derived tumor xenograft (PDX) mouse models of ovarian cancer and discusses current humanized mouse models of ovarian cancer. Expert opinion: The authors suggest that humanized mouse models of ovarian cancer will provide new insight into the role of the human immune system in combating and augmenting ovarian cancer and aid in the development of novel therapeutics. Development of humanized mouse models will take advantage of the NSG and NSG-SGM3 strains of mice as well as new strains that are actively being derived.

How Genetically Engineered Mouse Tumor Models Provide Insights Into Human Cancers

PubMed Central

Politi, Katerina; Pao, William

2011-01-01

Genetically engineered mouse models (GEMMs) of human cancer were first created nearly 30 years ago. These early transgenic models demonstrated that mouse cells could be transformed in vivo by expression of an oncogene. A new field emerged, dedicated to generating and using mouse models of human cancer to address a wide variety of questions in cancer biology. The aim of this review is to highlight the contributions of mouse models to the diagnosis and treatment of human cancers. Because of the breadth of the topic, we have selected representative examples of how GEMMs are clinically relevant rather than provided an exhaustive list of experiments. Today, as detailed here, sophisticated mouse models are being created to study many aspects of cancer biology, including but not limited to mechanisms of sensitivity and resistance to drug treatment, oncogene cooperation, early detection, and metastasis. Alternatives to GEMMs, such as chemically induced or spontaneous tumor models, are not discussed in this review. PMID:21263096

Integrating model behavior, optimization, and sensitivity/uncertainty analysis: overview and application of the MOUSE software toolbox

USDA-ARS?s Scientific Manuscript database

This paper provides an overview of the Model Optimization, Uncertainty, and SEnsitivity Analysis (MOUSE) software application, an open-source, Java-based toolbox of visual and numerical analysis components for the evaluation of environmental models. MOUSE is based on the OPTAS model calibration syst...

Regulation of Synaptic Amyloid-β Generation through BACE1 Retrograde Transport in a Mouse Model of Alzheimer's Disease

PubMed Central

Ye, Xuan; Chang, Qing; Jeong, Yu Young; Cai, Huaibin; Kusnecov, Alexander

2017-01-01

Amyloid-β (Aβ) peptides play a key role in synaptic damage and memory deficits in the early pathogenesis of Alzheimer's disease (AD). Abnormal accumulation of Aβ at nerve terminals leads to synaptic pathology and ultimately to neurodegeneration. β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is the major neuronal β-secretase for Aβ generation. However, the mechanisms regulating BACE1 distribution in axons and β cleavage of APP at synapses remain largely unknown. Here, we reveal that dynein–Snapin-mediated retrograde transport regulates BACE1 trafficking in axons and APP processing at presynaptic terminals. BACE1 is predominantly accumulated within late endosomes at the synapses of AD-related mutant human APP (hAPP) transgenic (Tg) mice and patient brains. Defective retrograde transport by genetic ablation of snapin in mice recapitulates late endocytic retention of BACE1 and increased APP processing at presynaptic sites. Conversely, overexpressing Snapin facilitates BACE1 trafficking and reduces synaptic BACE1 accumulation by enhancing the removal of BACE1 from distal AD axons and presynaptic terminals. Moreover, elevated Snapin expression via stereotactic hippocampal injections of adeno-associated virus particles in mutant hAPP Tg mouse brains decreases synaptic Aβ levels and ameliorates synapse loss, thus rescuing cognitive impairments associated with hAPP mice. Altogether, our study provides new mechanistic insights into the complex regulation of BACE1 trafficking and presynaptic localization through Snapin-mediated dynein-driven retrograde axonal transport, thereby suggesting a potential approach of modulating Aβ levels and attenuating synaptic deficits in AD. SIGNIFICANCE STATEMENT β-Site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) trafficking and synaptic localization significantly influence its β secretase activity and amyloid-β (Aβ) production. In AD brains, BACE1 is accumulated within dystrophic neurites, which is thought to augment Aβ-induced synaptotoxicity by Aβ overproduction. However, it remains largely unknown whether axonal transport regulates synaptic APP processing. Here, we demonstrate that Snapin-mediated retrograde transport plays a critical role in removing BACE1 from presynaptic terminals toward the soma, thus reducing synaptic Aβ production. Adeno-associated virus–mediated Snapin overexpression in the hippocampus of mutant hAPP mice significantly decreases synaptic Aβ levels, attenuates synapse loss, and thus rescues cognitive deficits. Our study uncovers a new pathway that controls synaptic APP processing by enhancing axonal BACE1 trafficking, thereby advancing our fundamental knowledge critical for ameliorating Aβ-linked synaptic pathology. PMID:28159908

Disrupting the male germ line to find infertility and contraception targets.

PubMed

Archambeault, Denise R; Matzuk, Martin M

2014-05-01

Genetically-manipulated mouse models have become indispensible for broadening our understanding of genes and pathways related to male germ cell development. Until suitable in vitro systems for studying spermatogenesis are perfected, in vivo models will remain the gold standard for inquiry into testicular function. Here, we discuss exciting advances that are allowing researchers faster, easier, and more customizable access to their mouse models of interest. Specifically, the trans-NIH Knockout Mouse Project (KOMP) is working to generate knockout mouse models of every gene in the mouse genome. The related Knockout Mouse Phenotyping Program (KOMP2) is performing systematic phenotypic analysis of this genome-wide collection of knockout mice, including fertility screening. Together, these programs will not only uncover new genes involved in male germ cell development but also provide the research community with the mouse models necessary for further investigations. In addition to KOMP/KOMP2, another promising development in the field of mouse models is the advent of CRISPR (clustered regularly interspaced short palindromic repeat)-Cas technology. Utilizing 20 nucleotide guide sequences, CRISPR/Cas has the potential to introduce sequence-specific insertions, deletions, and point mutations to produce null, conditional, activated, or reporter-tagged alleles. CRISPR/Cas can also successfully target multiple genes in a single experimental step, forgoing the multiple generations of breeding traditionally required to produce mouse models with deletions, insertions, or mutations in multiple genes. In addition, CRISPR/Cas can be used to create mouse models carrying variants identical to those identified in infertile human patients, providing the opportunity to explore the effects of such mutations in an in vivo system. Both the KOMP/KOMP2 projects and the CRISPR/Cas system provide powerful, accessible genetic approaches to the study of male germ cell development in the mouse. A more complete understanding of male germ cell biology is critical for the identification of novel targets for potential non-hormonal contraceptive intervention. Copyright © 2014. Published by Elsevier Masson SAS.

Genome-Wide Expression Profiling of Five Mouse Models Identifies Similarities and Differences with Human Psoriasis

PubMed Central

Swindell, William R.; Johnston, Andrew; Carbajal, Steve; Han, Gangwen; Wohn, Christian; Lu, Jun; Xing, Xianying; Nair, Rajan P.; Voorhees, John J.; Elder, James T.; Wang, Xiao-Jing; Sano, Shigetoshi; Prens, Errol P.; DiGiovanni, John; Pittelkow, Mark R.; Ward, Nicole L.; Gudjonsson, Johann E.

2011-01-01

Development of a suitable mouse model would facilitate the investigation of pathomechanisms underlying human psoriasis and would also assist in development of therapeutic treatments. However, while many psoriasis mouse models have been proposed, no single model recapitulates all features of the human disease, and standardized validation criteria for psoriasis mouse models have not been widely applied. In this study, whole-genome transcriptional profiling is used to compare gene expression patterns manifested by human psoriatic skin lesions with those that occur in five psoriasis mouse models (K5-Tie2, imiquimod, K14-AREG, K5-Stat3C and K5-TGFbeta1). While the cutaneous gene expression profiles associated with each mouse phenotype exhibited statistically significant similarity to the expression profile of psoriasis in humans, each model displayed distinctive sets of similarities and differences in comparison to human psoriasis. For all five models, correspondence to the human disease was strong with respect to genes involved in epidermal development and keratinization. Immune and inflammation-associated gene expression, in contrast, was more variable between models as compared to the human disease. These findings support the value of all five models as research tools, each with identifiable areas of convergence to and divergence from the human disease. Additionally, the approach used in this paper provides an objective and quantitative method for evaluation of proposed mouse models of psoriasis, which can be strategically applied in future studies to score strengths of mouse phenotypes relative to specific aspects of human psoriasis. PMID:21483750

Postmortem Findings for 7 Neonates with Congenital Zika Virus Infection.

PubMed

Sousa, Anastácio Q; Cavalcante, Diane I M; Franco, Luciano M; Araújo, Fernanda M C; Sousa, Emília T; Valença-Junior, José Telmo; Rolim, Dionne B; Melo, Maria E L; Sindeaux, Pedro D T; Araújo, Marialva T F; Pearson, Richard D; Wilson, Mary E; Pompeu, Margarida M L

2017-07-01

Postmortem examination of 7 neonates with congenital Zika virus infection in Brazil revealed microcephaly, ventriculomegaly, dystrophic calcifications, and severe cortical neuronal depletion in all and arthrogryposis in 6. Other findings were leptomeningeal and brain parenchymal inflammation and pulmonary hypoplasia and lymphocytic infiltration in liver and lungs. Findings confirmed virus neurotropism and multiple organ infection.

[Effect of topical application of a recombinant adenovirus carrying promyelocytic leukemia gene in a psoriasis-like mouse model].

PubMed

Wang, Qiongyu; Zhang, Aijun; Ma, Huiqun; Wang, Shijie; Ma, Yunyun; Zou, Xingwei; Li, Ruilian

2013-03-01

To investigate the effects of topical treatment with adenovirus-mediated promyelocytic leukemia gene (PML) gene in a psoriasis-like mouse model. The effect of adenovirus-mediated PML gene on the granular layer of mouse tail scale epidermis and epithelial mitosis were observed on longitudinal histological sections prepared from the tail skin and vaginal epithelium of the mice. Adenovirus-mediated PML gene significantly inhibited mitosis of mouse vaginal epithelial cells and promoted the formation of granular layer in mouse tail scale epidermis. The therapeutic effect of PML gene in the psoriasis-like mouse model may be associated with increased granular cells and suppressed epidemic cell proliferation.

Generation of transgenic mouse model using PTTG as an oncogene.

PubMed

Kakar, Sham S; Kakar, Cohin

2015-01-01

The close physiological similarity between the mouse and human has provided tools to understanding the biological function of particular genes in vivo by introduction or deletion of a gene of interest. Using a mouse as a model has provided a wealth of resources, knowledge, and technology, helping scientists to understand the biological functions, translocation, trafficking, and interaction of a candidate gene with other intracellular molecules, transcriptional regulation, posttranslational modification, and discovery of novel signaling pathways for a particular gene. Most importantly, the generation of the mouse model for a specific human disease has provided a powerful tool to understand the etiology of a disease and discovery of novel therapeutics. This chapter describes in detail the step-by-step generation of the transgenic mouse model, which can be helpful in guiding new investigators in developing successful models. For practical purposes, we will describe the generation of a mouse model using pituitary tumor transforming gene (PTTG) as the candidate gene of interest.

What Is the Predictive Value of Animal Models for Vaccine Efficacy in Humans? Reevaluating the Potential of Mouse Models for the Human Immune System.

PubMed

Jameson, Stephen C; Masopust, David

2018-04-02

Much of what we understand about immunology, including the response to vaccines, come from studies in mice because they provide many practical advantages compared with research in higher mammals and humans. Nevertheless, modalities for preventing or treating disease do not always translate from mouse to humans, which has led to increasing scrutiny of the continued merits of mouse research. Here, we summarize the pros and cons of current laboratory mouse models for immunology research and discuss whether overreliance on nonphysiological, ultra-hygienic animal husbandry approaches has limited the ultimate translation potential of mouse-derived data to humans. Alternative approaches are discussed that may extend the use of the mouse model for preclinical studies. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Enhancing Endogenous Nitric Oxide by Whole Body Periodic Acceleration Elicits Neuroprotective Effects in Dystrophic Neurons.

PubMed

Lopez, Jose R; Uryash, A; Kolster, J; Estève, E; Zhang, R; Adams, J A

2018-03-26

We have previously shown that inadequate dystrophin in cortical neurons in mdx mice is associated with age-dependent dyshomeostasis of resting intracellular Ca 2+ ([Ca 2+ ] i ) and Na + ([Na + ] i ), elevated reactive oxygen species (ROS) production, increase in neuronal damage and cognitive deficit. In this study, we assessed the potential therapeutic properties of the whole body periodic acceleration (pGz) to ameliorate the pathology observed in cortical neurons from the mdx mouse. pGz adds small pulses to the circulation, thereby increasing pulsatile shear stress to the vascular endothelium, which in turn increases production of nitric oxide (NO). We found [Ca 2+ ] i and [Na + ] i overload along with reactive oxygen species (ROS) overproduction in mdx neurons and cognitive dysfunction. mdx neurons showed increased activity of superoxide dismutase, glutathione peroxidase, malondialdehyde, and calpain as well as decreased cell viability. mdx neurons were more susceptible to hypoxia-reoxygenation injury than WT. pGz ameliorated the [Ca 2+ ] i , and [Na + ] i elevation and ROS overproduction and further increased the activities of superoxide dismutase, glutathione peroxidase and reduced the malondialdehyde and calpains. pGz diminished cell damage and elevated [Ca 2+ ] i during hypoxia-reoxygenation and improved cognitive function in mdx mice. Moreover, pGz upregulated the expression of utrophin, dystroglycan-β and CAPON, constitutive nitric oxide synthases, prosaposin, brain-derived neurotrophic, and glial cell line-derived neurotrophic factors. The present study demonstrated that pGz is an effective therapeutic approach to improve mdx neurons function, including cognitive functions.

Voluntary wheel running in dystrophin-deficient (mdx) mice: Relationships between exercise parameters and exacerbation of the dystrophic phenotype.

PubMed

Smythe, Gayle M; White, Jason D

2011-12-18

Voluntary wheel running can potentially be used to exacerbate the disease phenotype in dystrophin-deficient mdx mice. While it has been established that voluntary wheel running is highly variable between individuals, the key parameters of wheel running that impact the most on muscle pathology have not been examined in detail. We conducted a 2-week test of voluntary wheel running by mdx mice and the impact of wheel running on disease pathology. There was significant individual variation in the average daily distance (ranging from 0.003 ± 0.005 km to 4.48 ± 0.96 km), culminating in a wide range (0.040 km to 67.24 km) of total cumulative distances run by individuals. There was also variation in the number and length of run/rest cycles per night, and the average running rate. Correlation analyses demonstrated that in the quadriceps muscle, a low number of high distance run/rest cycles was the most consistent indicator for increased tissue damage. The amount of rest time between running bouts was a key factor associated with gastrocnemius damage. These data emphasize the need for detailed analysis of individual running performance, consideration of the length of wheel exposure time, and the selection of appropriate muscle groups for analysis, when applying the use of voluntary wheel running to disease exacerbation and/or pre-clinical testing of the efficacy of therapeutic agents in the mdx mouse.

Mouse Models in Bone Marrow Transplantation and Adoptive Cellular Therapy

PubMed Central

Arber, Caroline; Brenner, Malcolm K.; Reddy, Pavan

2014-01-01

Mouse models of transplantation have been indispensable to the development of bone marrow transplantation (BMT). Their role in the generation of basic science knowledge is invaluable and is subject to discussion below. However, this article focuses on the direct role and relevance of mouse models towards the clinical development and advances in BMT and adoptive T-cell therapy for human diseases. The authors aim to present a thoughtful perspective on the pros and cons of mouse models while noting that despite imperfections these models are obligatory for the development of science-based medicine. PMID:24216170

Centralized mouse repositories.

PubMed

Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

2012-10-01

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

Centralized Mouse Repositories

PubMed Central

Donahue, Leah Rae; de Angelis, Martin Hrabe; Hagn, Michael; Franklin, Craig; Lloyd, K. C. Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T.

2013-01-01

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world. PMID:22945696

Molecular Indicators of Stress-Induced Neuroinflammation in a Mouse Model Simulating Features of Post-Traumatic Stress Disorder (Open Access)

DTIC Science & Technology

2017-05-23

OPEN ORIGINAL ARTICLE Molecular indicators of stress-induced neuroinflammation in a mouse model simulating features of post -traumatic stress disorder... post -traumatic stress disorder (PTSD). The model involved exposure of an intruder (male C57BL/6) mouse to a resident aggressor (male SJL) mouse for 5...revealed that neurogenesis and synaptic plasticity pathways were activated during the early responses but were inhibited after the later post -trauma

Genetic characterization and improved genotyping of the dysferlin-deficient mouse strain Dysf (tm1Kcam).

PubMed

Wiktorowicz, Tatiana; Kinter, Jochen; Kobuke, Kazuhiro; Campbell, Kevin P; Sinnreich, Michael

2015-01-01

Mouse models of dysferlinopathies are valuable tools with which to investigate the pathomechanisms underlying these diseases and to test novel therapeutic strategies. One such mouse model is the Dysf (tm1Kcam) strain, which was generated using a targeting vector to replace a 12-kb region of the dysferlin gene and which features a progressive muscular dystrophy. A prerequisite for successful animal studies using genetic mouse models is an accurate genotyping protocol. Unfortunately, the lack of robustness of currently available genotyping protocols for the Dysf (tm1Kcam) mouse has prevented efficient colony management. Initial attempts to improve the genotyping protocol based on the published genomic structure failed. These difficulties led us to analyze the targeted locus of the dysferlin gene of the Dysf (tm1Kcam) mouse in greater detail. In this study we resequenced and analyzed the targeted locus of the Dysf (tm1Kcam) mouse and developed a novel PCR protocol for genotyping. We found that instead of a deletion, the dysferlin locus in the Dysf (tm1Kcam) mouse carries a targeted insertion. This genetic characterization enabled us to establish a reliable method for genotyping of the Dysf (tm1Kcam) mouse, and thus has made efficient colony management possible. Our work will make the Dysf (tm1Kcam) mouse model more attractive for animal studies of dysferlinopathies.

Mouse models of neurodegenerative diseases: criteria and general methodology.

PubMed

Janus, Christopher; Welzl, Hans

2010-01-01

The major symptom of Alzheimer's disease is rapidly progressing dementia, coinciding with the formation of amyloid and tau deposits in the central nervous system, and neuronal death. At present familial cases of dementias provide the most promising foundation for modelling neurodegeneration. We describe the mnemonic and other major behavioral symptoms of tauopathies, briefly outline the genetics underlying familiar cases and discuss the arising implications for modelling the disease in mostly transgenic mouse lines. We then depict to what degree the most recent mouse models replicate pathological and cognitive characteristics observed in patients.There is no universally valid behavioral test battery to evaluate mouse models. The selection of individual tests depends on the behavioral and/or memory system in focus, the type of a model and how well it replicates the pathology of a disease and the amount of control over the genetic background of the mouse model. However it is possible to provide guidelines and criteria for modelling the neurodegeneration, setting up the experiments and choosing relevant tests. One should not adopt a "one (trans)gene, one disease" interpretation, but should try to understand how the mouse genome copes with the protein expression of the transgene in question. Further, it is not possible to recommend some mouse models over others since each model is valuable within its own constraints, and the way experiments are performed often reflects the idiosyncratic reality of specific laboratories. Our purpose is to improve bridging molecular and behavioural approaches in translational research.

Direct comparison of the pharmacodynamics of four antifungal drugs in a mouse model of disseminated candidiasis using microbiological assays of serum drug concentrations.

PubMed

Maki, Katsuyuki; Holmes, Ann R; Watabe, Etsuko; Iguchi, Yumi; Matsumoto, Satoru; Ikeda, Fumiaki; Tawara, Shuichi; Mutoh, Seitaro

2007-01-01

The aim of this study was to compare the pharmacodynamics of the azole antifungal drugs fluconazole, itraconazole and ketoconazole, and the polyene antifungal amphotericin B, in a mouse model of disseminated Candida albicans infection. In order to directly compare effective serum concentrations of these antifungals, drug concentrations were assayed microbiologically by measuring inhibition of C. albicans mycelial growth (mMIC) in a mouse serum-based assay (serum antifungal titer). Efficacy in the mouse infection model was determined using an organ-based (kidney burden) endpoint. For all four drugs, the serum antifungal titers, 8 hr after administration of single doses of drugs at a range of drug concentrations, correlated closely with C. albicans kidney fungal burden in the mouse model. The results showed that determining serum antifungal titer may be used to accurately represent kidney fungal burden in a mouse model of disseminated candidiasis and allowed direct comparison of the pharmacodynamics of differing classes of antifungal drugs.

Mouse Models as Tools to Identify Genetic Pathways for Retinal Degeneration, as Exemplified by Leber's Congenital Amaurosis.

PubMed

Chang, Bo

2016-01-01

Leber's congenital amaurosis (LCA) is an inherited retinal degenerative disease characterized by severe loss of vision in the first year of life. In addition to early vision loss, a variety of other eye-related abnormalities including roving eye movements, deep-set eyes, and sensitivity to bright light also occur with this disease. Many animal models of LCA are available and the study them has led to a better understanding of the pathology of the disease, and has led to the development of therapeutic strategies aimed at curing or slowing down LCA. Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human LCA. Such mice provide reproducible, experimental systems for elucidating pathways of normal development, function, designing strategies and testing compounds for translational research and gene-based therapies aimed at delaying the diseases progression. In this chapter, I describe tools used in the discovery and evaluation of mouse models of LCA including a Phoenix Image-Guided Optical Coherence Tomography (OCT) and a Diagnosys Espion Visual Electrophysiology System. Three mouse models are described, the rd3 mouse model for LCA12 and LCA1, the rd12 mouse model for LCA2, and the rd16 mouse model for LCA10.

Differences in Pathogenesis for Salmonella enterica serovar Typhimurium in the Mouse Versus the Swine Model Identify Bacterial Gene Products Required for Systemic but not Gastrointestinal Disease

USDA-ARS?s Scientific Manuscript database

Over the last several decades, the mouse model of Typhoid fever has been an extremely productive model to investigate Salmonella enterica serovar Typhimurium pathogenesis. The mouse is the paradigm for investigating systemic disease due to infection by Salmonella; however, the swine model of gastro...

Contractility and supersensitivity to adrenaline in dystrophic muscle.

PubMed Central

Takamori, M

1975-01-01

In the adductor pollicis muscle of patients with limb-girdle and facioscapulohumeral muscular dystrophies and possible carriers of Duchenne type muscular dystrophy, abnormal active state properties were found at the time when there was no alteration of needle electromyography and evoked muscle action potentials. Adrenaline induced a marked reduction of incomplete tetanus via beta receptors without change in neuromuscular transmission. PMID:1151415

Dystrophic heart failure blocked by membrane sealant poloxamer

NASA Astrophysics Data System (ADS)

Yasuda, Soichiro; Townsend, Dewayne; Michele, Daniel E.; Favre, Elizabeth G.; Day, Sharlene M.; Metzger, Joseph M.

2005-08-01

Dystrophin deficiency causes Duchenne muscular dystrophy (DMD) in humans, an inherited and progressive disease of striated muscle deterioration that frequently involves pronounced cardiomyopathy. Heart failure is the second leading cause of fatalities in DMD. Progress towards defining the molecular basis of disease in DMD has mostly come from studies on skeletal muscle, with comparatively little attention directed to cardiac muscle. The pathophysiological mechanisms involved in cardiac myocytes may differ significantly from skeletal myofibres; this is underscored by the presence of significant cardiac disease in patients with truncated or reduced levels of dystrophin but without skeletal muscle disease. Here we show that intact, isolated dystrophin-deficient cardiac myocytes have reduced compliance and increased susceptibility to stretch-mediated calcium overload, leading to cell contracture and death, and that application of the membrane sealant poloxamer 188 corrects these defects in vitro. In vivo administration of poloxamer 188 to dystrophic mice instantly improved ventricular geometry and blocked the development of acute cardiac failure during a dobutamine-mediated stress protocol. Once issues relating to optimal dosing and long-term effects of poloxamer 188 in humans have been resolved, chemical-based membrane sealants could represent a new therapeutic approach for preventing or reversing the progression of cardiomyopathy and heart failure in muscular dystrophy.

Human COL7A1-corrected induced pluripotent stem cells for the treatment of recessive dystrophic epidermolysis bullosa

PubMed Central

Sebastiano, Vittorio; Zhen, Hanson Hui; Haddad, Bahareh; Bashkirova, Elizaveta; Melo, Sandra P.; Wang, Pei; Leung, Thomas L.; Siprashvili, Zurab; Tichy, Andrea; Li, Jiang; Ameen, Mohammed; Hawkins, John; Lee, Susie; Li, Lingjie; Schwertschkow, Aaron; Bauer, Gerhard; Lisowski, Leszek; Kay, Mark A.; Kim, Seung K.; Lane, Alfred T.; Wernig, Marius; Oro, Anthony E.

2015-01-01

Patients with recessive dystrophic epidermolysis bullosa (RDEB) lack functional type VII collagen owing to mutations in the gene COL7A1 and suffer severe blistering and chronic wounds that ultimately lead to infection and development of lethal squamous cell carcinoma. The discovery of induced pluripotent stem cells (iPSCs) and the ability to edit the genome bring the possibility to provide definitive genetic therapy through corrected autologous tissues. We generated patient-derived COL7A1-corrected epithelial keratinocyte sheets for autologous grafting. We demonstrate the utility of sequential reprogramming and adenovirus-associated viral genome editing to generate corrected iPSC banks. iPSC-derived keratinocytes were produced with minimal heterogeneity, and these cells secreted wild-type type VII collagen, resulting in stratified epidermis in vitro in organotypic cultures and in vivo in mice. Sequencing of corrected cell lines before tissue formation revealed heterogeneity of cancer-predisposing mutations, allowing us to select COL7A1-corrected banks with minimal mutational burden for downstream epidermis production. Our results provide a clinical platform to use iPSCs in the treatment of debilitating genodermatoses, such as RDEB. PMID:25429056

Transcriptome and ultrastructural changes in dystrophic Epidermolysis bullosa resemble skin aging

PubMed Central

Trost, Andrea; Weber, Manuela; Klausegger, Alfred; Gruber, Christina; Bruckner, Daniela; Reitsamer, Herbert A.; Bauer, Johann W.; Breitenbach, Michael

2015-01-01

The aging process of skin has been investigated recently with respect to mitochondrial function and oxidative stress. We have here observed striking phenotypic and clinical similarity between skin aging and recessive dystrophic Epidermolysis bullosa (RDEB), which is caused by recessive mutations in the gene coding for collagen VII, COL7A1. Ultrastructural changes, defects in wound healing, and inflammation markers are in part shared with aged skin. We have here compared the skin transcriptomes of young adults suffering from RDEB with that of sex‐ and age‐matched healthy probands. In parallel we have compared the skin transcriptome of healthy young adults with that of elderly healthy donors. Quite surprisingly, there was a large overlap of the two gene lists that concerned a limited number of functional protein families. Most prominent among the proteins found are a number of proteins of the cornified envelope or proteins mechanistically involved in cornification and other skin proteins. Further, the overlap list contains a large number of genes with a known role in inflammation. We are documenting some of the most prominent ultrastructural and protein changes by immunofluorescence analysis of skin sections from patients, old individuals, and healthy controls. PMID:26143532

HDAC2 blockade by nitric oxide and histone deacetylase inhibitors reveals a common target in Duchenne muscular dystrophy treatment.

PubMed

Colussi, Claudia; Mozzetta, Chiara; Gurtner, Aymone; Illi, Barbara; Rosati, Jessica; Straino, Stefania; Ragone, Gianluca; Pescatori, Mario; Zaccagnini, Germana; Antonini, Annalisa; Minetti, Giulia; Martelli, Fabio; Piaggio, Giulia; Gallinari, Paola; Steinkuhler, Christian; Steinkulher, Christian; Clementi, Emilio; Dell'Aversana, Carmela; Altucci, Lucia; Mai, Antonello; Capogrossi, Maurizio C; Puri, Pier Lorenzo; Gaetano, Carlo

2008-12-09

The overlapping histological and biochemical features underlying the beneficial effect of deacetylase inhibitors and NO donors in dystrophic muscles suggest an unanticipated molecular link among dystrophin, NO signaling, and the histone deacetylases (HDACs). Higher global deacetylase activity and selective increased expression of the class I histone deacetylase HDAC2 were detected in muscles of dystrophin-deficient MDX mice. In vitro and in vivo siRNA-mediated down-regulation of HDAC2 in dystrophic muscles was sufficient to replicate the morphological and functional benefits observed with deacetylase inhibitors and NO donors. We found that restoration of NO signaling in vivo, by adenoviral-mediated expression of a constitutively active endothelial NOS mutant in MDX muscles, and in vitro, by exposing MDX-derived satellite cells to NO donors, resulted in HDAC2 blockade by cysteine S-nitrosylation. These data reveal a special contribution of HDAC2 in the pathogenesis of Duchenne muscular dystrophy and indicate that HDAC2 inhibition by NO-dependent S-nitrosylation is important for the therapeutic response to NO donors in MDX mice. They also define a common target for independent pharmacological interventions in the treatment of Duchenne muscular dystrophy.

HDAC2 blockade by nitric oxide and histone deacetylase inhibitors reveals a common target in Duchenne muscular dystrophy treatment

PubMed Central

Colussi, Claudia; Mozzetta, Chiara; Gurtner, Aymone; Illi, Barbara; Rosati, Jessica; Straino, Stefania; Ragone, Gianluca; Pescatori, Mario; Zaccagnini, Germana; Antonini, Annalisa; Minetti, Giulia; Martelli, Fabio; Piaggio, Giulia; Gallinari, Paola; Steinkuhler, Christian; Clementi, Emilio; Dell'Aversana, Carmela; Altucci, Lucia; Mai, Antonello; Capogrossi, Maurizio C.; Puri, Pier Lorenzo; Gaetano, Carlo

2008-01-01

The overlapping histological and biochemical features underlying the beneficial effect of deacetylase inhibitors and NO donors in dystrophic muscles suggest an unanticipated molecular link among dystrophin, NO signaling, and the histone deacetylases (HDACs). Higher global deacetylase activity and selective increased expression of the class I histone deacetylase HDAC2 were detected in muscles of dystrophin-deficient MDX mice. In vitro and in vivo siRNA-mediated down-regulation of HDAC2 in dystrophic muscles was sufficient to replicate the morphological and functional benefits observed with deacetylase inhibitors and NO donors. We found that restoration of NO signaling in vivo, by adenoviral-mediated expression of a constitutively active endothelial NOS mutant in MDX muscles, and in vitro, by exposing MDX-derived satellite cells to NO donors, resulted in HDAC2 blockade by cysteine S-nitrosylation. These data reveal a special contribution of HDAC2 in the pathogenesis of Duchenne muscular dystrophy and indicate that HDAC2 inhibition by NO-dependent S-nitrosylation is important for the therapeutic response to NO donors in MDX mice. They also define a common target for independent pharmacological interventions in the treatment of Duchenne muscular dystrophy. PMID:19047631

Transcriptome and ultrastructural changes in dystrophic Epidermolysis bullosa resemble skin aging.

PubMed

Breitenbach, Jenny S; Rinnerthaler, Mark; Trost, Andrea; Weber, Manuela; Klausegger, Alfred; Gruber, Christina; Bruckner, Daniela; Reitsamer, Herbert A; Bauer, Johann W; Breitenbach, Michael

2015-06-01

The aging process of skin has been investigated recently with respect to mitochondrial function and oxidative stress. We have here observed striking phenotypic and clinical similarity between skin aging and recessive dystrophic Epidermolysis bullosa (RDEB), which is caused by recessive mutations in the gene coding for collagen VII,COL7A1. Ultrastructural changes, defects in wound healing, and inflammation markers are in part shared with aged skin. We have here compared the skin transcriptomes of young adults suffering from RDEB with that of sex- and age-matched healthy probands. In parallel we have compared the skin transcriptome of healthy young adults with that of elderly healthy donors. Quite surprisingly, there was a large overlap of the two gene lists that concerned a limited number of functional protein families. Most prominent among the proteins found are a number of proteins of the cornified envelope or proteins mechanistically involved in cornification and other skin proteins. Further, the overlap list contains a large number of genes with a known role in inflammation. We are documenting some of the most prominent ultrastructural and protein changes by immunofluorescence analysis of skin sections from patients, old individuals, and healthy controls.

Lysyl Hydroxylase 3 Localizes to Epidermal Basement Membrane and Is Reduced in Patients with Recessive Dystrophic Epidermolysis Bullosa

PubMed Central

Watt, Stephen A.; Dayal, Jasbani H. S.; Wright, Sheila; Riddle, Megan; Pourreyron, Celine; McMillan, James R.; Kimble, Roy M.; Prisco, Marco; Gartner, Ulrike; Warbrick, Emma; McLean, W. H. Irwin; Leigh, Irene M.; McGrath, John A.; Salas-Alanis, Julio C.; Tolar, Jakub; South, Andrew P.

2015-01-01

Recessive dystrophic epidermolysis bullosa (RDEB) is caused by mutations in COL7A1 resulting in reduced or absent type VII collagen, aberrant anchoring fibril formation and subsequent dermal-epidermal fragility. Here, we identify a significant decrease in PLOD3 expression and its encoded protein, the collagen modifying enzyme lysyl hydroxylase 3 (LH3), in RDEB. We show abundant LH3 localising to the basement membrane in normal skin which is severely depleted in RDEB patient skin. We demonstrate expression is in-part regulated by endogenous type VII collagen and that, in agreement with previous studies, even small reductions in LH3 expression lead to significantly less secreted LH3 protein. Exogenous type VII collagen did not alter LH3 expression in cultured RDEB keratinocytes and we show that RDEB patients receiving bone marrow transplantation who demonstrate significant increase in type VII collagen do not show increased levels of LH3 at the basement membrane. Our data report a direct link between LH3 and endogenous type VII collagen expression concluding that reduction of LH3 at the basement membrane in patients with RDEB will likely have significant implications for disease progression and therapeutic intervention. PMID:26380979

[Anaesthetic management in a paediatric patient with a difficult airway due to epidermolysis bullosa dystrophica].

PubMed

Blázquez Gómez, E; Garcés Aletá, A; Monclus Diaz, E; Manen Berga, F; García-Aparicio, L; Ontanilla López, A

2015-05-01

Dystrophic epidermolysis bullosa (DEB) is a rare inherited disorder characterized by blistering after minimal trauma. These blisters tend to form dystrophic scars, leading to limiting and life-threatening sequelae. The anaesthetic management of patients with DEB is a challenge, even for the most experienced anaesthesiologists, but basic principles can help us prepare the plan of care. The main goals are to prevent trauma/infection of skin/mucous, and to establish a secure airway without causing bullae. Patient positioning and the instruments used to monitor vital signs and administering anaesthetic agents can cause new lesions. It is advisable to lubricate the instruments and to avoid adhesive material and shearing forces on the skin. Besides the implications of the comorbidities, there is a potential difficult intubation and difficult vascular access. Acute airway obstruction can occur due to airway instrumentation. We report the case of a patient diagnosed with EBD difficult airway and undergoing correction of syndactylyl and dental extractions. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

A unified model of the excitability of mouse sensory and motor axons.

PubMed

Makker, Preet G S; Matamala, José Manuel; Park, Susanna B; Lees, Justin G; Kiernan, Matthew C; Burke, David; Moalem-Taylor, Gila; Howells, James

2018-06-19

Non-invasive nerve excitability techniques have provided valuable insight into the understanding of neurological disorders. The widespread use of mice in translational research on peripheral nerve disorders and by pharmaceutical companies during drug development requires valid and reliable models that can be compared to humans. This study established a novel experimental protocol that enables comparative assessment of the excitability properties of motor and sensory axons at the same site in mouse caudal nerve, compared the mouse data to data for motor and sensory axons in human median nerve at the wrist, and constructed a mathematical model of the excitability of mouse axons. In a separate study, ischaemia was employed as an experimental manoeuvre to test the translational utility of this preparation. The patterns of mouse sensory and motor excitability were qualitatively similar to human studies under normal and ischaemic conditions. The most conspicuous differences between mouse and human studies were observed in the recovery cycle and the response to hyperpolarization. Modelling showed that an increase in temperature in mouse axons could account for most of the differences in the recovery cycle. The modelling also suggested a larger hyperpolarization-activated conductance in mouse axons. The kinetics of this conductance appeared to be much slower raising the possibility that an additional or different hyperpolarization-activated cyclic-nucleotide gated (HCN) channel isoform underlies the accommodation to hyperpolarization in mouse axons. Given a possible difference in HCN isoforms, caution should be exercised in extrapolating from studies of mouse motor and sensory axons to human nerve disorders. This article is protected by copyright. All rights reserved.

Rapamycin improves sociability in the BTBR T(+)Itpr3(tf)/J mouse model of autism spectrum disorders.

PubMed

Burket, Jessica A; Benson, Andrew D; Tang, Amy H; Deutsch, Stephen I

2014-01-01

Overactivation of the mammalian target of rapamycin (mTOR) has been implicated in the pathogenesis of syndromic forms of autism spectrum disorders (ASDs), such as tuberous sclerosis complex, neurofibromatosis 1, and fragile X syndrome. Administration of mTORC1 (mTOR complex 1) inhibitors (e.g. rapamycin) in syndromic mouse models of ASDs improved behavior, cognition, and neuropathology. However, since only a minority of ASDs are due to the effects of single genes (∼10%), there is a need to explore inhibition of mTOR activity in mouse models that may be more relevant to the majority of nonsyndromic presentations, such as the genetically inbred BTBR T(+)Itpr3(tf)/J (BTBR) mouse model of ASDs. BTBR mice have social impairment and exhibit increased stereotypic behavior. In prior work, d-cycloserine, a partial glycineB site agonist that targets the N-methyl-d-aspartate (NMDA) receptor, was shown to improve sociability in both Balb/c and BTBR mouse models of ASDs. Importantly, NMDA receptor activation regulates mTOR signaling activity. The current study investigated the ability of rapamycin (10mg/kg, i.p.×four days), an mTORC1 inhibitor, to improve sociability and stereotypic behavior in BTBR mice. Using a standard paradigm to assess mouse social behavior, rapamycin improved several measures of sociability in the BTBR mouse, suggesting that mTOR overactivation represents a therapeutic target that mediates or contributes to impaired sociability in the BTBR mouse model of ASDs. Interestingly, there was no effect of rapamycin on stereotypic behaviors in this mouse model. Copyright © 2013 Elsevier Inc. All rights reserved.

In Vivo Hyperthermic Stress Model: An Easy Tool to Study the Effects of Oxidative Stress on Neuronal Tau Functionality in Mouse Brain.

PubMed

Chauderlier, Alban; Delattre, Lucie; Buée, Luc; Galas, Marie-Christine

2017-01-01

Oxidative damage is an early event in neurodegenerative disorders such as Alzheimer disease. To increase oxidative stress in AD-related mouse models is essential to study early mechanisms involved in the physiopathology of these diseases. In this chapter, we describe an experimental mouse model of transient and acute hyperthermic stress to induce in vivo an increase of oxidative stress in the brain of any kind of wild-type or transgenic mouse.

Implementation of a manual for working with wobbler mice and criteria for discontinuation of the experiment.

PubMed

Ott, Bastian; Dahlke, Carolin; Meller, Karl; Napirei, Markus; Schmitt-John, Thomas; Brand-Saberi, Beate; Theiss, Carsten; Saberi, Darius

2015-07-01

Mouse breeding is of importance to a whole range of medical and biological research. There are many known mouse models for motor neuron diseases. However, it must be kept in mind that especially mouse models for amyotrophic lateral sclerosis develop severe symptoms causing intense stress. This article is designed to summarize conscientious work with the wobbler mouse, a model for the sporadic form of amyotrophic lateral sclerosis. This mouse model is characterized by a degeneration of α-motor-neurons leading to head tremor, loss of body weight and rapidly progressive paralysis. Although this mouse model has been known since 1956, there are no guidelines for breeding wobbler mice. Due to the lack of such guidelines the present study tries to close this gap and implements a manual for further studies. It includes the whole workflow in regard to wobbler mice from breeding and animal care taking, genotyping and phenotype analysis, but also gives some examples for the use of various neuronal tissues for histological investigation. Beside the progress in research a second aim should always be the enhancement of mouse welfare and reduction of stress for the laboratory animals. Copyright © 2015 Elsevier GmbH. All rights reserved.

Rational Design of Mouse Models for Cancer Research.

PubMed

Landgraf, Marietta; McGovern, Jacqui A; Friedl, Peter; Hutmacher, Dietmar W

2018-03-01

The laboratory mouse is widely considered as a valid and affordable model organism to study human disease. Attempts to improve the relevance of murine models for the investigation of human pathologies led to the development of various genetically engineered, xenograft and humanized mouse models. Nevertheless, most preclinical studies in mice suffer from insufficient predictive value when compared with cancer biology and therapy response of human patients. We propose an innovative strategy to improve the predictive power of preclinical cancer models. Combining (i) genomic, tissue engineering and regenerative medicine approaches for rational design of mouse models with (ii) rapid prototyping and computational benchmarking against human clinical data will enable fast and nonbiased validation of newly generated models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Review of DoD Malaria Research Programs,

DTIC Science & Technology

1992-05-01

the irraliated sporozoite vaccine. Work in the mouse model system and then extrapolate to human malarias. Study naturally acquired immune ...recombinant vaccines. Work simultaneously in the mouse model system and with human malarias. 3. Identify targets and mechanisms of protective immunity not...multivalent vaccines that attack these same targets. 3. Working again in the mouse model, non- human primate model, andI human systems we

Animal models for prenatal gene therapy: rodent models for prenatal gene therapy.

PubMed

Roybal, Jessica L; Endo, Masayuki; Buckley, Suzanne M K; Herbert, Bronwen R; Waddington, Simon N; Flake, Alan W

2012-01-01

Fetal gene transfer has been studied in various animal models, including rabbits, guinea pigs, cats, dogs, and nonhuman primate; however, the most common model is the rodent, particularly the mouse. There are numerous advantages to mouse models, including a short gestation time of around 20 days, large litter size usually of more than six pups, ease of colony maintenance due to the small physical size, and the relatively low expense of doing so. Moreover, the mouse genome is well defined, there are many transgenic models particularly of human monogenetic disorders, and mouse-specific biological reagents are readily available. One criticism has been that it is difficult to perform procedures on the fetal mouse with suitable accuracy. Over the past decade, accumulation of technical expertise and development of technology such as high-frequency ultrasound have permitted accurate vector delivery to organs and tissues. Here, we describe our experiences of gene transfer to the fetal mouse with and without ultrasound guidance from mid to late gestation. Depending upon the vector type, the route of delivery and the age of the fetus, specific or widespread gene transfer can be achieved, making fetal mice excellent models for exploratory biodistribution studies.

Altered ROS production, NF-κB activation and interleukin-6 gene expression induced by electrical stimulation in dystrophic mdx skeletal muscle cells.

PubMed

Henríquez-Olguín, Carlos; Altamirano, Francisco; Valladares, Denisse; López, José R; Allen, Paul D; Jaimovich, Enrique

2015-07-01

Duchenne muscular dystrophy is a fatal X-linked genetic disease, caused by mutations in the dystrophin gene, which cause functional loss of this protein. This pathology is associated with an increased production of reactive oxygen (ROS) and nitrogen species. The aim of this work was to study the alterations in NF-κB activation and interleukin-6 (IL-6) expression induced by membrane depolarization in dystrophic mdx myotubes. Membrane depolarization elicited by electrical stimulation increased p65 phosphorylation, NF-κB transcriptional activity and NF-κB-dependent IL-6 expression in wt myotubes, whereas in mdx myotubes it had the opposite effect. We have previously shown that depolarization-induced intracellular Ca2+ increases and ROS production are necessary for NF-κB activation and stimulation of gene expression in wt myotubes. Dystrophic myotubes showed a reduced amplitude and area under the curve of the Ca2+ transient elicited by electrical stimulation. On the other hand, electrical stimuli induced higher ROS production in mdx than wt myotubes, which were blocked by NOX2 inhibitors. Moreover, mRNA expression and protein levels of the NADPH oxidase subunits: p47phox and gp91phox were increased in mdx myotubes. Looking at ROS-dependence of NF-κB activation we found that in wt myotubes external administration of 50 μM H2O2 increased NF-κB activity; after administration of 100 and 200 μM H2O2 there was no effect. In mdx myotubes there was a dose-dependent reduction in NF-κB activity in response to external administration of H2O2, with a significant effect of 100 μM and 200 μM, suggesting that ROS levels are critical for NF-κB activity. Prior blockage with NOX2 inhibitors blunted the effects of electrical stimuli in both NF-κB activation and IL-6 expression. Finally, to ascertain whether stimulation of NF-κB and IL-6 gene expression by the inflammatory pathway is also impaired in mdx myotubes, we studied the effect of lipopolysaccharide on both NF-κB activation and IL-6 expression. Exposure to lipopolysaccharide induced a dramatic increase in both NF-κB activation and IL-6 expression in both wt and mdx myotubes, suggesting that the altered IL-6 gene expression after electrical stimulation in mdx muscle cells is due to dysregulation of Ca2+ release and ROS production, both of which impinge on NF-κB signaling. IL-6 is a key metabolic modulator that is released by the skeletal muscle to coordinate a multi-systemic response (liver, muscle, and adipocytes) during physical exercise; the alteration of this response in dystrophic muscles may contribute to an abnormal response to contraction and exercise. Copyright © 2015. Published by Elsevier B.V.

Treatment of d-galactose induced mouse aging with Lycium barbarum polysaccharides and its mechanism study.

PubMed

Tang, Tao; He, Bixiu

2013-01-01

We evaluated the effects of Lycium barbarum polysaccharides LBP) on D-galactose aging model mouse, and explored its possible mechanism. Kunming mice were randomly divided into the control group, the model group, the high-dose LBP group, and the low-dose LBP group. Except the control group, D-galactose was used for modelling. The drug was administrated when modelling. Mouse behavioural, learning and memory changes were observed, and the contents of lipid peroxidation (LPO), lipofuscin (LF) and monoamine oxidase B (MAO-B) in mouse brain tissue and the weight of immune organs were measured after 6 weeks. Compared with the control group, mouse weight gain in the model group reduced significantly. Compared with model group, after mice drank LBP, the times of electric shock was less than aging mice (in which, the high-dose LBP group, P<0.05), and electric shock incubation period was longer (P<0.01). On Day 45 after modelling and drug administration, the contents of LPO, LF and MAO-B in mouse brain tissue in the model group increased significantly, while those in the drug administration groups decreased significantly. The thymus index in the aging model group decreased significantly; the thymus index and the spleen index in the high-dose LBP group and the low-dose LBP group rebounded significantly (P<0.01). We concluded that LBP has an anti-aging effect on D-galactose induced aging model mouse, and its mechanism may be related with the alleviation of glucose metabolism disorder and the resistance of the generation of lipid peroxide and other substances, which damage cell membrane lipid.

Mutagenicity testing with transgenic mice. Part II: Comparison with the mouse spot test

PubMed Central

Wahnschaffe, Ulrich; Bitsch, Annette; Kielhorn, Janet; Mangelsdorf, Inge

2005-01-01

The mouse spot test, an in vivo mutation assay, has been used to assess a number of chemicals. It is at present the only in vivo mammalian test system capable of detecting somatic gene mutations according to OECD guidelines (OECD guideline 484). It is however rather insensitive, animal consuming and expensive type of test. More recently several assays using transgenic animals have been developed. From data in the literature, the present study compares the results of in vivo testing of over twenty chemicals using the mouse spot test and compares them with results from the two transgenic mouse models with the best data base available, the lacI model (commercially available as the Big Blue® mouse), and the lacZ model (commercially available as the Muta™ Mouse). There was agreement in the results from the majority of substances. No differences were found in the predictability of the transgenic animal assays and the mouse spot test for carcinogenicity. However, from the limited data available, it seems that the transgenic mouse assay has several advantages over the mouse spot test and may be a suitable test system replacing the mouse spot test for detection of gene but not chromosome mutations in vivo. PMID:15676065

The Mouse Genome Database (MGD): facilitating mouse as a model for human biology and disease.

PubMed

Eppig, Janan T; Blake, Judith A; Bult, Carol J; Kadin, James A; Richardson, Joel E

2015-01-01

The Mouse Genome Database (MGD, http://www.informatics.jax.org) serves the international biomedical research community as the central resource for integrated genomic, genetic and biological data on the laboratory mouse. To facilitate use of mouse as a model in translational studies, MGD maintains a core of high-quality curated data and integrates experimentally and computationally generated data sets. MGD maintains a unified catalog of genes and genome features, including functional RNAs, QTL and phenotypic loci. MGD curates and provides functional and phenotype annotations for mouse genes using the Gene Ontology and Mammalian Phenotype Ontology. MGD integrates phenotype data and associates mouse genotypes to human diseases, providing critical mouse-human relationships and access to repositories holding mouse models. MGD is the authoritative source of nomenclature for genes, genome features, alleles and strains following guidelines of the International Committee on Standardized Genetic Nomenclature for Mice. A new addition to MGD, the Human-Mouse: Disease Connection, allows users to explore gene-phenotype-disease relationships between human and mouse. MGD has also updated search paradigms for phenotypic allele attributes, incorporated incidental mutation data, added a module for display and exploration of genes and microRNA interactions and adopted the JBrowse genome browser. MGD resources are freely available to the scientific community. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Genetically engineered mouse models of craniopharyngioma: an opportunity for therapy development and understanding of tumor biology

PubMed Central

Martinez‐Barbera, Juan Pedro

2017-01-01

Abstract Adamantinomatous craniopharyngioma (ACP) is the commonest tumor of the sellar region in childhood. Two genetically engineered mouse models have been developed and are giving valuable insights into ACP biology. These models have identified novel pathways activated in tumors, revealed an important function of paracrine signalling and extended conventional theories about the role of organ‐specific stem cells in tumorigenesis. In this review, we summarize these mouse models, what has been learnt, their limitations and open questions for future research. We then discussed how these mouse models may be used to test novel therapeutics against potentially targetable pathways recently identified in human ACP. PMID:28414891

TREATMENT OF DYSENTERY IN EXPERIMENTAL RADIATION SICKNESS (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodskaya, E.A.; Emaikina, V.P.; Kostritsa, A.G.

1959-01-01

Experiments with 53 cats (one group exposed to 275 r and the other to 500 r and infected with the Flexner dysentery) showed that the exposure to 275 r did not change the general condition of the cats while the 800 r resulted in a sharp rise of temperature, dirrhea, heavy dystrophic-necrotic changes in the intestines, and peculiar mucous and submucous processes. (R.V.J.)

T2 mapping provides multiple approaches to characterize muscle involvement in neuromuscular diseases: a cross-sectional study of lower leg muscles in 5–15 year old boys with Duchenne Muscular Dystrophy

PubMed Central

Arpan, Ishu; Forbes, Sean C; Lott, Donovan J; Senesac, Claudia R; Daniels, Michael J; Triplett, William T; Deol, Jasjit K; Sweeney, H Lee; Walter, Glenn A; Vandenborne, Krista

2012-01-01

Purpose Skeletal muscles of children with Duchenne muscular dystrophy (DMD) have enhanced susceptibility to damage and progressive lipid infiltration, which contribute to an increase in magnetic resonance proton transverse relaxation time (T2). Therefore, examining T2 changes in individual muscles may be useful for monitoring disease progression in DMD. In this study we utilized mean T2, percent elevated pixels, and T2 heterogeneity to assess changes in composition of dystrophic muscles. In addition, we used fat saturation (fatsat) to distinguish T2 changes due to edema and inflammation from fat infiltration in muscles. Methods Thirty subjects with DMD and 15 age-matched controls underwent T2-weighted imaging of their lower leg using 3-T MR system. T2 maps were developed and four lower leg muscles were manually traced (soleus, medial gastrocnemius, peroneal and tibialis anterior). Mean T2 of the traced regions of interest (ROI), width of T2 histograms, and percent-elevated pixels were calculated. Results We found that even in young children with DMD, muscles had elevated mean T2, were more heterogeneous, and had a greater percent-elevated pixels in the lower leg muscles than controls. T2 measures decreased with fat saturation, but were still higher (p<0.05) in dystrophic muscles than controls. Further, T2 measures showed positive correlations with timed functional tests (r=0.23–0.79). Conclusion The elevated T2 measures with and without fat saturation in all ages of DMD examined (5–15 years) compared to unaffected controls indicate that the dystrophic muscles have increased regions of damage, edema, and fat infiltration. This study shows that T2 mapping provides multiple approaches that can be effectively utilized to characterize muscle tissue in children with DMD even in the early stages of the disease. Therefore, T2 mapping may prove clinically useful in monitoring muscle changes due to disease process or therapeutic interventions in DMD. PMID:23044995

T₂ mapping provides multiple approaches for the characterization of muscle involvement in neuromuscular diseases: a cross-sectional study of lower leg muscles in 5-15-year-old boys with Duchenne muscular dystrophy.

PubMed

Arpan, Ishu; Forbes, Sean C; Lott, Donovan J; Senesac, Claudia R; Daniels, Michael J; Triplett, William T; Deol, Jasjit K; Sweeney, H Lee; Walter, Glenn A; Vandenborne, Krista

2013-03-01

Skeletal muscles of children with Duchenne muscular dystrophy (DMD) show enhanced susceptibility to damage and progressive lipid infiltration, which contribute to an increase in the MR proton transverse relaxation time (T₂). Therefore, the examination of T₂ changes in individual muscles may be useful for the monitoring of disease progression in DMD. In this study, we used the mean T₂, percentage of elevated pixels and T₂ heterogeneity to assess changes in the composition of dystrophic muscles. In addition, we used fat saturation to distinguish T₂ changes caused by edema and inflammation from fat infiltration in muscles. Thirty subjects with DMD and 15 age-matched controls underwent T₂ -weighted imaging of their lower leg using a 3-T MR system. T₂ maps were developed and four lower leg muscles were manually traced (soleus, medial gastrocnemius, peroneal and tibialis anterior). The mean T₂ of the traced regions of interest, width of the T₂ histograms and percentage of elevated pixels were calculated. We found that, even in young children with DMD, lower leg muscles showed elevated mean T₂, were more heterogeneous and had a greater percentage of elevated pixels than in controls. T₂ measures decreased with fat saturation, but were still higher (P < 0.05) in dystrophic muscles than in controls. Further, T₂ measures showed positive correlations with timed functional tests (r = 0.23-0.79). The elevated T₂ measures with and without fat saturation at all ages of DMD examined (5-15 years) compared with unaffected controls indicate that the dystrophic muscles have increased regions of damage, edema and fat infiltration. This study shows that T₂ mapping provides multiple approaches that can be used effectively to characterize muscle tissue in children with DMD, even in the early stages of the disease. Therefore, T₂ mapping may prove to be clinically useful in the monitoring of muscle changes caused by the disease process or by therapeutic interventions in DMD. Copyright © 2012 John Wiley & Sons, Ltd.

Mouse neuroblastoma cell based model and the effect of epileptic events on calcium oscillations and neural spikes

NASA Astrophysics Data System (ADS)

Kim, Suhwan; Baek, Juyeong; Jung, Unsang; Lee, Sangwon; Jung, Woonggyu; Kim, Jeehyun; Kang, Shinwon

2013-05-01

Recently, Mouse neuroblastoma cells are considered as an attractive model for the study of human neurological and prion diseases, and intensively used as a model system in different areas. Among those areas, differentiation of neuro2a (N2A) cells, receptor mediated ion current, and glutamate induced physiological response are actively investigated. The reason for the interest to mouse neuroblastoma N2A cells is that they have a fast growing rate than other cells in neural origin with a few another advantages. This study evaluated the calcium oscillations and neural spikes recording of mouse neuroblastoma N2A cells in an epileptic condition. Based on our observation of neural spikes in mouse N2A cell with our proposed imaging modality, we report that mouse neuroblastoma N2A cells can be an important model related to epileptic activity studies. It is concluded that the mouse neuroblastoma N2A cells produce the epileptic spikes in vitro in the same way as produced by the neurons or the astrocytes. This evidence advocates the increased and strong level of neurotransmitters release by enhancement in free calcium using the 4-aminopyridine which causes the mouse neuroblastoma N2A cells to produce the epileptic spikes and calcium oscillation.

Dynamics of circulating gamma delta T cell activity in an immunocompetent mouse model of high-grade glioma

USDA-ARS?s Scientific Manuscript database

Human gamma delta T cells are potent effectors against glioma cell lines in vitro and in human/mouse xenograft models of glioblastoma, however, this effect has not been investigated in an immunocompetent mouse model. In this report, we established GL261 intracranial gliomas in syngeneic WT C57BL/6 m...

Lack of species-specific difference in pulmonary function when using mouse versus human plasma in a mouse model of hemorrhagic shock.

PubMed

Peng, Zhanglong; Pati, Shibani; Fontaine, Magali J; Hall, Kelly; Herrera, Anthony V; Kozar, Rosemary A

2016-11-01

Clinical studies have demonstrated that the early and empiric use of plasma improves survival after hemorrhagic shock. We have demonstrated in rodent models of hemorrhagic shock that resuscitation with plasma is protective to the lungs compared with lactated Ringer's solution. As our long-term objective is to determine the molecular mechanisms that modulate plasma's protective effects in injured bleeding patients, we have used human plasma in a mouse model of hemorrhagic shock. The goal of the current experiments is to determine if there are significant adverse effects on lung injury when using human versus mouse plasma in an established murine model of hemorrhagic shock and laparotomy. Mice underwent laparotomy and 90 minutes of hemorrhagic shock to a mean arterial pressure (MAP) of 35 ± 5 mm Hg followed by resuscitation at 1× shed blood using either mouse fresh frozen plasma (FFP), human FFP, or human lyophilized plasma. Mean arterial pressure was recorded during shock and for the first 30 minutes of resuscitation. After 3 hours, animals were killed, and lungs collected for analysis. There was a significant increase in early MAP when mouse FFP was used to resuscitate animals compared with human FFP or human lyophilized plasma. However, despite these differences, analysis of the mouse lungs revealed no significant differences in pulmonary histopathology, lung permeability, or lung edema between all three plasma groups. Analysis of neutrophil infiltration in the lungs revealed that mouse FFP decreased neutrophil influx as measured by neutrophil staining; however, myeloperoxidase immunostaining revealed no significant differences in between groups. The study of human plasma in a mouse model of hemorrhagic shock is feasible but does reveal some differences compared with mouse plasma-based resuscitation in physiologic measures such as MAP postresuscitation. Measures of end organ function such as lung injury appear to be comparable in this acute model of hemorrhagic shock and resuscitation.

In vivo quantitative bioluminescence tomography using heterogeneous and homogeneous mouse models.

PubMed

Liu, Junting; Wang, Yabin; Qu, Xiaochao; Li, Xiangsi; Ma, Xiaopeng; Han, Runqiang; Hu, Zhenhua; Chen, Xueli; Sun, Dongdong; Zhang, Rongqing; Chen, Duofang; Chen, Dan; Chen, Xiaoyuan; Liang, Jimin; Cao, Feng; Tian, Jie

2010-06-07

Bioluminescence tomography (BLT) is a new optical molecular imaging modality, which can monitor both physiological and pathological processes by using bioluminescent light-emitting probes in small living animal. Especially, this technology possesses great potential in drug development, early detection, and therapy monitoring in preclinical settings. In the present study, we developed a dual modality BLT prototype system with Micro-computed tomography (MicroCT) registration approach, and improved the quantitative reconstruction algorithm based on adaptive hp finite element method (hp-FEM). Detailed comparisons of source reconstruction between the heterogeneous and homogeneous mouse models were performed. The models include mice with implanted luminescence source and tumor-bearing mice with firefly luciferase report gene. Our data suggest that the reconstruction based on heterogeneous mouse model is more accurate in localization and quantification than the homogeneous mouse model with appropriate optical parameters and that BLT allows super-early tumor detection in vivo based on tomographic reconstruction of heterogeneous mouse model signal.

Of Mice and Men: Comparative Analysis of Neuro-Inflammatory Mechanisms in Human and Mouse Using Cause-and-Effect Models.

PubMed

Kodamullil, Alpha Tom; Iyappan, Anandhi; Karki, Reagon; Madan, Sumit; Younesi, Erfan; Hofmann-Apitius, Martin

2017-01-01

Perturbance in inflammatory pathways have been identified as one of the major factors which leads to neurodegenerative diseases (NDD). Owing to the limited access of human brain tissues and the immense complexity of the brain, animal models, specifically mouse models, play a key role in advancing the NDD field. However, many of these mouse models fail to reproduce the clinical manifestations and end points of the disease. NDD drugs, which passed the efficacy test in mice, were repeatedly not successful in clinical trials. There are numerous studies which are supporting and opposing the applicability of mouse models in neuroinflammation and NDD. In this paper, we assessed to what extend a mouse can mimic the cellular and molecular interactions in humans at a mechanism level. Based on our mechanistic modeling approach, we investigate the failure of a neuroinflammation targeted drug in the late phases of clinical trials based on the comparative analyses between the two species.

NCI Mouse Repository | FNLCR Staging

Cancer.gov

The NCI Mouse Repository is an NCI-funded resource for mouse cancer models and associated strains. The repository makes strains available to all members of the scientific community (academic, non-profit, and commercial). NCI Mouse Repository strains

An extended Kalman filter for mouse tracking.

PubMed

Choi, Hongjun; Kim, Mingi; Lee, Onseok

2018-05-19

Animal tracking is an important tool for observing behavior, which is useful in various research areas. Animal specimens can be tracked using dynamic models and observation models that require several types of data. Tracking mouse has several barriers due to the physical characteristics of the mouse, their unpredictable movement, and cluttered environments. Therefore, we propose a reliable method that uses a detection stage and a tracking stage to successfully track mouse. The detection stage detects the surface area of the mouse skin, and the tracking stage implements an extended Kalman filter to estimate the state variables of a nonlinear model. The changes in the overall shape of the mouse are tracked using an oval-shaped tracking model to estimate the parameters for the ellipse. An experiment is conducted to demonstrate the performance of the proposed tracking algorithm using six video images showing various types of movement, and the ground truth values for synthetic images are compared to the values generated by the tracking algorithm. A conventional manual tracking method is also applied to compare across eight experimenters. Furthermore, the effectiveness of the proposed tracking method is also demonstrated by applying the tracking algorithm with actual images of mouse. Graphical abstract.

Mouse Models for Down Syndrome-Associated Developmental Cognitive Disabilities

PubMed Central

Liu, Chunhong; Belichenko, Pavel V.; Zhang, Li; Fu, Dawei; Kleschevnikov, Alexander M.; Baldini, Antonio; Antonarakis, Stylianos E.; Mobley, William C.; Yu, Y. Eugene

2011-01-01

Down syndrome (DS) is mainly caused by the presence of an extra copy of human chromosome 21 (Hsa21) and is a leading genetic cause for developmental cognitive disabilities in humans. The mouse is a premier model organism for DS because the regions on Hsa21 are syntenically conserved with three regions in the mouse genome, which are located on mouse chromosome 10 (Mmu10), Mmu16 and Mmu17. With the advance of chromosomal manipulation technologies, new mouse mutants have been generated to mimic DS at both the genotypic and phenotypic levels. Further mouse-based molecular genetic studies in the future may lead to the unraveling of the mechanisms underlying DS-associated developmental cognitive disabilities, which would lay the groundwork for developing effective treatments for this phenotypic manifestation. In this review, we will discuss recent progress and future challenges in modeling DS-associated developmental cognitive disability in mice with an emphasis on hippocampus-related phenotypes. PMID:21865664

Methods in Molecular Biology Mouse Genetics: Methods and Protocols | Center for Cancer Research

Cancer.gov

Mouse Genetics: Methods and Protocols provides selected mouse genetic techniques and their application in modeling varieties of human diseases. The chapters are mainly focused on the generation of different transgenic mice to accomplish the manipulation of genes of interest, tracing cell lineages, and modeling human diseases.

Use of mouse models to study the mechanisms and consequences of RBC clearance

PubMed Central

Hod, E. A.; Arinsburg, S. A.; Francis, R. O.; Hendrickson, J. E.; Zimring, J. C.; Spitalnik, S. L.

2013-01-01

Mice provide tractable animal models for studying the pathophysiology of various human disorders. This review discusses the use of mouse models for understanding red-blood-cell (RBC) clearance. These models provide important insights into the pathophysiology of various clinically relevant entities, such as autoimmune haemolytic anaemia, haemolytic transfusion reactions, other complications of RBC transfusions and immunomodulation by Rh immune globulin therapy. Mouse models of both antibody- and non-antibody-mediated RBC clearance are reviewed. Approaches for exploring unanswered questions in transfusion medicine using these models are also discussed. PMID:20345515

Generation Of A Mouse Model For Schwannomatosis

DTIC Science & Technology

2010-09-01

TITLE: Generation of a Mouse Model for Schwannomatosis PRINCIPAL INVESTIGATOR: Long-Sheng Chang, Ph.D. CONTRACTING ORGANIZATION: The...Annual 3. DATES COVERED (From - To) 1 Sep 2009 - 31 Aug 2010 4. TITLE AND SUBTITLE Generation of a Mouse Model for Schwannomatosis 5a. CONTRACT...hypothesis involving inactivation of both the INI1/SNF5 and NF2 tumor suppressor genes in the formation of schwannomatosis -associated tumors. To

Mouse Genome Database: From sequence to phenotypes and disease models

PubMed Central

Richardson, Joel E.; Kadin, James A.; Smith, Cynthia L.; Blake, Judith A.; Bult, Carol J.

2015-01-01

Summary The Mouse Genome Database (MGD, www.informatics.jax.org) is the international scientific database for genetic, genomic, and biological data on the laboratory mouse to support the research requirements of the biomedical community. To accomplish this goal, MGD provides broad data coverage, serves as the authoritative standard for mouse nomenclature for genes, mutants, and strains, and curates and integrates many types of data from literature and electronic sources. Among the key data sets MGD supports are: the complete catalog of mouse genes and genome features, comparative homology data for mouse and vertebrate genes, the authoritative set of Gene Ontology (GO) annotations for mouse gene functions, a comprehensive catalog of mouse mutations and their phenotypes, and a curated compendium of mouse models of human diseases. Here, we describe the data acquisition process, specifics about MGD's key data areas, methods to access and query MGD data, and outreach and user help facilities. genesis 53:458–473, 2015. © 2015 The Authors. Genesis Published by Wiley Periodicals, Inc. PMID:26150326

Establishing a laboratory animal model from a transgenic animal: RasH2 mice as a model for carcinogenicity studies in regulatory science.

PubMed

Urano, K; Tamaoki, N; Nomura, T

2012-01-01

Transgenic animal models have been used in small numbers in gene function studies in vivo for a period of time, but more recently, the use of a single transgenic animal model has been approved as a second species, 6-month alternative (to the routine 2-year, 2-animal model) used in short-term carcinogenicity studies for generating regulatory application data of new drugs. This article addresses many of the issues associated with the creation and use of one of these transgenic models, the rasH2 mouse, for regulatory science. The discussion includes strategies for mass producing mice with the same stable phenotype, including constructing the transgene, choosing a founder mouse, and controlling both the transgene and background genes; strategies for developing the model for regulatory science, including measurements of carcinogen susceptibility, stability of a large-scale production system, and monitoring for uniform carcinogenicity responses; and finally, efficient use of the transgenic animal model on study. Approximately 20% of mouse carcinogenicity studies for new drug applications in the United States currently use transgenic models, typically the rasH2 mouse. The rasH2 mouse could contribute to animal welfare by reducing the numbers of animals used as well as reducing the cost of carcinogenicity studies. A better understanding of the advantages and disadvantages of the transgenic rasH2 mouse will result in greater and more efficient use of this animal model in the future.

NCI Mouse Repository | Frederick National Laboratory for Cancer Research

Cancer.gov

The NCI Mouse Repository is an NCI-funded resource for mouse cancer models and associated strains. The repository makes strains available to all members of the scientific community (academic, non-profit, and commercial). NCI Mouse Repository strains

Low-Level Laser Therapy (LLLT) in Dystrophin-Deficient Muscle Cells: Effects on Regeneration Capacity, Inflammation Response and Oxidative Stress.

PubMed

Macedo, Aline Barbosa; Moraes, Luis Henrique Rapucci; Mizobuti, Daniela Sayuri; Fogaça, Aline Reis; Moraes, Fernanda Dos Santos Rapucci; Hermes, Tulio de Almeida; Pertille, Adriana; Minatel, Elaine

2015-01-01

The present study evaluated low-level laser therapy (LLLT) effects on some physiological pathways that may lead to muscle damage or regeneration capacity in dystrophin-deficient muscle cells of mdx mice, the experimental model of Duchenne muscular dystrophy (DMD). Primary cultures of mdx skeletal muscle cells were irradiated only one time with laser and analyzed after 24 and 48 hours. The LLLT parameter used was 830 nm wavelengths at 5 J/cm² fluence. The following groups were set up: Ctrl (untreated C57BL/10 primary muscle cells), mdx (untreated mdx primary muscle cells), mdx LA 24 (mdx primary muscle cells - LLLT irradiated and analyzed after 24 h), and mdx LA 48 (mdx primary muscle cells - LLLT irradiated and analyzed after 48 h). The mdx LA 24 and mdx LA 48 groups showed significant increase in cell proliferation, higher diameter in muscle cells and decreased MyoD levels compared to the mdx group. The mdx LA 48 group showed significant increase in Myosin Heavy Chain levels compared to the untreated mdx and mdx LA 24 groups. The mdx LA 24 and mdx LA 48 groups showed significant increase in [Ca2+]i. The mdx group showed significant increase in H2O2 production and 4-HNE levels compared to the Ctrl group and LLLT treatment reduced this increase. GSH levels and GPx, GR and SOD activities increased in the mdx group. Laser treatment reduced the GSH levels and GR and SOD activities in dystrophic muscle cells. The mdx group showed significant increase in the TNF-α and NF-κB levels, which in turn was reduced by the LLLT treatment. Together, these results suggest that the laser treatment improved regenerative capacity and decreased inflammatory response and oxidative stress in dystrophic muscle cells, indicating that LLLT could be a helpful alternative therapy to be associated with other treatment for dystrophinopathies.

Differential Gene Expression Profiling of Dystrophic Dog Muscle after MuStem Cell Transplantation

PubMed Central

Babarit, Candice; Larcher, Thibaut; Dubreil, Laurence; Leroux, Isabelle; Zuber, Céline; Ledevin, Mireille; Deschamps, Jack-Yves; Fromes, Yves; Cherel, Yan; Guevel, Laetitia; Rouger, Karl

2015-01-01

Background Several adult stem cell populations exhibit myogenic regenerative potential, thus representing attractive candidates for therapeutic approaches of neuromuscular diseases such as Duchenne Muscular Dystrophy (DMD). We have recently shown that systemic delivery of MuStem cells, skeletal muscle-resident stem cells isolated in healthy dog, generates the remodelling of muscle tissue and gives rise to striking clinical benefits in Golden Retriever Muscular Dystrophy (GRMD) dog. This global effect, which is observed in the clinically relevant DMD animal model, leads us to question here the molecular pathways that are impacted by MuStem cell transplantation. To address this issue, we compare the global gene expression profile between healthy, GRMD and MuStem cell treated GRMD dog muscle, four months after allogenic MuStem cell transplantation. Results In the dystrophic context of the GRMD dog, disease-related deregulation is observed in the case of 282 genes related to various processes such as inflammatory response, regeneration, calcium ion binding, extracellular matrix organization, metabolism and apoptosis regulation. Importantly, we reveal the impact of MuStem cell transplantation on several molecular and cellular pathways based on a selection of 31 genes displaying signals specifically modulated by the treatment. Concomitant with a diffuse dystrophin expression, a histological remodelling and a stabilization of GRMD dog clinical status, we show that cell delivery is associated with an up-regulation of genes reflecting a sustained enhancement of muscle regeneration. We also identify a decreased mRNA expression of a set of genes having metabolic functions associated with lipid homeostasis and energy. Interestingly, ubiquitin-mediated protein degradation is highly enhanced in GRMD dog muscle after systemic delivery of MuStem cells. Conclusions Overall, our results provide the first high-throughput characterization of GRMD dog muscle and throw new light on the complex molecular/cellular effects associated with muscle repair and the clinical efficacy of MuStem cell-based therapy. PMID:25955839

Therapeutic effects of autologous lymphocytes activated with trastuzumab for xenograft mouse models of human breast cancer.

PubMed

Nakagawa, Shinichiro; Matsuoka, Yusuke; Ichihara, Hideaki; Yoshida, Hitoji; Yoshida, Kenshi; Ueoka, Ryuichi

2013-01-01

Trastuzumab (TTZ) is molecular targeted drug used for metastatic breast cancer patients overexpressing human epidermal growth factor receptor 2 (HER2). Therapeutic effects of lymphocytes activated with TTZ (TTZ-LAK) using xenograft mouse models of human breast cancer (MDA-MB-453) cells were examined in vivo. Remarkable reduction of tumor volume in a xenograft mouse models intravenously treated with TTZ-LAK cells after the subcutaneously inoculated of MDA-MB-453 cells was verified in vivo. The migration of TTZ-LAK cells in tumor of mouse models subcutaneously inoculated MDA-MB-453 cells was observed on the basis of histological analysis using immunostaining with CD-3. Induction of apoptosis in tumor of xenograft mice treated with TTZ-LAK cells was observed in micrographs using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) method. It was noteworthy that the therapeutic effects of TTZ-LAK cells along with apoptosis were obtained for xenograft mouse models of human breast tumor in vivo.

Generation of a neuro-specific microarray reveals novel differentially expressed noncoding RNAs in mouse models for neurodegenerative diseases.

PubMed

Gstir, Ronald; Schafferer, Simon; Scheideler, Marcel; Misslinger, Matthias; Griehl, Matthias; Daschil, Nina; Humpel, Christian; Obermair, Gerald J; Schmuckermair, Claudia; Striessnig, Joerg; Flucher, Bernhard E; Hüttenhofer, Alexander

2014-12-01

We have generated a novel, neuro-specific ncRNA microarray, covering 1472 ncRNA species, to investigate their expression in different mouse models for central nervous system diseases. Thereby, we analyzed ncRNA expression in two mouse models with impaired calcium channel activity, implicated in Epilepsy or Parkinson's disease, respectively, as well as in a mouse model mimicking pathophysiological aspects of Alzheimer's disease. We identified well over a hundred differentially expressed ncRNAs, either from known classes of ncRNAs, such as miRNAs or snoRNAs or which represented entirely novel ncRNA species. Several differentially expressed ncRNAs in the calcium channel mouse models were assigned as miRNAs and target genes involved in calcium signaling, thus suggesting feedback regulation of miRNAs by calcium signaling. In the Alzheimer mouse model, we identified two snoRNAs, whose expression was deregulated prior to amyloid plaque formation. Interestingly, the presence of snoRNAs could be detected in cerebral spine fluid samples in humans, thus potentially serving as early diagnostic markers for Alzheimer's disease. In addition to known ncRNAs species, we also identified 63 differentially expressed, entirely novel ncRNA candidates, located in intronic or intergenic regions of the mouse genome, genomic locations, which previously have been shown to harbor the majority of functional ncRNAs. © 2014 Gstir et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

PDX-1 Is a Therapeutic Target for Pancreatic Cancer, Insulinoma and Islet Neoplasia Using a Novel RNA Interference Platform

PubMed Central

Liu, Shi-He; Rao, Donald D.; Nemunaitis, John; Senzer, Neil; Zhou, Guisheng; Dawson, David; Gingras, Marie-Claude; Wang, Zhaohui; Gibbs, Richard; Norman, Michael; Templeton, Nancy S.; DeMayo, Francesco J.; O'Malley, Bert; Sanchez, Robbi; Fisher, William E.; Brunicardi, F. Charles

2012-01-01

Pancreatic and duodenal homeobox-1 (PDX-1) is a transcription factor that regulates insulin expression and islet maintenance in the adult pancreas. Our recent studies demonstrate that PDX-1 is an oncogene for pancreatic cancer and is overexpressed in pancreatic cancer. The purpose of this study was to demonstrate that PDX-1 is a therapeutic target for both hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Immunohistochemistry of human pancreatic and islet neoplasia specimens revealed marked PDX-1 overexpression, suggesting PDX-1 as a “drugable” target within these diseases. To do so, a novel RNA interference effector platform, bifunctional shRNAPDX-1, was developed and studied in mouse and human cell lines as well as in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Systemic delivery of bi-shRNAhumanPDX-1 lipoplexes resulted in marked reduction of tumor volume and improved survival in a human pancreatic cancer xenograft mouse model. bi-shRNAmousePDX-1 lipoplexes prevented death from hyperinsulinemia and hypoglycemia in an insulinoma mouse model. shRNAmousePDX-1 lipoplexes reversed hyperinsulinemia and hypoglycemia in an immune-competent mouse model of islet neoplasia. PDX-1 was overexpressed in pancreatic neuroendocrine tumors and nesidioblastosis. These data demonstrate that PDX-1 RNAi therapy controls hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia, therefore, PDX-1 is a potential therapeutic target for these pancreatic diseases. PMID:22905092

Development and Characterization of a Mouse Model for Marburg Hemorrhagic Fever

DTIC Science & Technology

2009-07-01

Microbiology. All Rights Reserved. Development and Characterization of a Mouse Model for Marburg Hemorrhagic Fever Kelly L. Warfield,* Steven B...mouse model has hampered an understanding of the pathogenesis and immunity of Marburg hemorrhagic fever (MHF), the disease caused by marburgvirus (MARV...cause severe hemorrhagic fevers in humans and non- human primates (27). The incubation time is estimated to be 3 to 21 days, with human case fatality

Producing a Mouse Model to Explore the Linkages Between Tocopherol Biology and Prostate Cancer

DTIC Science & Technology

2005-07-01

Edwards, Prostate cancer and supplementation with alpha-tocopherol and beta -carotene: incidence and mortality in a controlled trial. J Natl Cancer ...1-0153 TITLE: Producing a Mouse Model to Explore the Linkages Between Tocopherol Biology and Prostate Cancer ...TITLE AND SUBTITLE Producing a Mouse Model to Explore the Linkages Between Tocopherol 5a. CONTRACT NUMBER Biology and Prostate Cancer 5b. GRANT

Synergistic Action of FOXP3 and TSC1 Pathways During Tumor Progression

DTIC Science & Technology

2015-10-01

invasive carcinoma and, ultimately, metastatic disease [1-3]. Mouse models of PIN (mPIN) generated by a single- mutant gene in prostate do not progress...downstream target) is sufficient to significantly reduce the initiation of prostate cancer in the Pten conditional knockout mouse model [19-21...the possibility that these two genetic hits cooperate to promote tumor progression, and mouse models show that this cooperation accelerates

Molecular Characterization of Squamous Cell Carcinomas From Recessive Dystrophic Epidermolysis Bullosa

DTIC Science & Technology

2006-09-01

junctions found primarily in epithelial tissues but also in certain non-epithelial tissues including the meninges, dendritic reticular cells of lymph node...epidermal thickening, a phenotype becoming more prominent in adult animals. To further examine the transition between the stratum granulosum and stratum...granular cell layers of wild-type and transgenic skin. In control epidermis, an abrupt transition was observed from the granular layer to the stratum

Designing Mouse Behavioral Tasks Relevant to Autistic-Like Behaviors

ERIC Educational Resources Information Center

Crawley, Jacqueline N.

2004-01-01

The importance of genetic factors in autism has prompted the development of mutant mouse models to advance our understanding of biological mechanisms underlying autistic behaviors. Mouse models of human neuropsychiatric diseases are designed to optimize (1) face validity, i.e., resemblance to the human symptoms; (2) construct validity, i.e.,…

Comparison of sarcoplasmic reticulum Ca2+-adenosine triphosphatase from vitamin E-deficient dystrophic rabbit skeletal muscle with iron-ascorbate-treated and untreated enzyme.

PubMed

Nirdnoy, W; Komaratat, P; Wilairat, P

1988-02-01

Sarcoplasmic reticulum Ca2+-ATPase from rabbit skeletal muscle has an Arrhenius curve of enzyme activity with a discontinuity at about 20 degrees C. Preparations treated with FeSO4 and ascorbic acid and from a vitamin E-deficient dystrophic rabbit have 22% of the normal activity and a linear Arrhenius curve (Promkhatkaew, D., Komaratat, P., & Wilairat, P. (1985) Biochem. Int. 10, 937-943). All three preparations were cross-linked to the same extent by dimethyl suberimidate and copper-phenanthroline reagent at temperatures above and below the temperature of the Arrhenius discontinuity. Both iron-ascorbate-treated Ca2+-ATPase and that from a vitamin E-deficient animal had 50% of the normal sulfhydryl content, but the disulfide and free amino contents were unaltered. These observations suggest that loss of sulfhydryl groups through lipid peroxidation, both in vivo and in vitro, resulted in reduction of Ca2+-ATPase activity and loss of the break in the Arrhenius plot. Changes in Ca2+-ATPase polypeptide aggregational state could not account for the discontinuity in the Arrhenius curve as revealed by the similar extent of cross-linking of the three enzyme preparations at temperatures above and below the temperature of the Arrhenius discontinuity.

Kinesin Mutations Cause Motor Neuron Disease Phenotypes by Disrupting Fast Axonal Transport in Drosophila

PubMed Central

Hurd, D. D.; Saxton, W. M.

1996-01-01

Previous work has shown that mutation of the gene that encodes the microtubule motor subunit kinesin heavy chain (Khc) in Drosophila inhibits neuronal sodium channel activity, action potentials and neurotransmitter secretion. These physiological defects cause progressive distal paralysis in larvae. To identify the cellular defects that cause these phenotypes, larval nerves were studied by light and electron microscopy. The axons of Khc mutants develop dramatic focal swellings along their lengths. The swellings are packed with fast axonal transport cargoes including vesicles, synaptic membrane proteins, mitochondria and prelysosomal organelles, but not with slow axonal transport cargoes such as cytoskeletal elements. Khc mutations also impair the development of larval motor axon terminals, causing dystrophic morphology and marked reductions in synaptic bouton numbers. These observations suggest that as the concentration of maternally provided wild-type KHC decreases, axonal organelles transported by kinesin periodically stall. This causes organelle jams that disrupt retrograde as well as anterograde fast axonal transport, leading to defective action potentials, dystrophic terminals, reduced transmitter secretion and progressive distal paralysis. These phenotypes parallel the pathologies of some vertebrate motor neuron diseases, including some forms of amyotrophic lateral sclerosis (ALS), and suggest that impaired fast axonal transport is a key element in those diseases. PMID:8913751

[Epidermolysis bullosa in peru: clinical and epidemiological study of patients treated in a national reference pediatric hospital, 1993-2015].

PubMed

Torres-Iberico, Rosario; Palomo-Luck, Patricia; Torres-Ramos, Gilmer; Lipa-Chancolla, Roxana

2017-01-01

To describe the clinical and epidemiological characteristics of patients diagnosed with epidermolysis bullosa (EB) at the Instituto Nacional de Salud (INSN) in Lima, Peru; a National Reference Center for this disease. Observational, descriptive and transversal study. We reviewed the clinical histories and laboratory tests of patients diagnosed with EB treated in INSN from 1993 to 2015. 93 patients were registered. The average age was 7.9 ± 5.6 years; 53.8% (n = 50) were boys. Clinical forms corresponded to dystrophic EB with 41 (44.1%) cases, simple EB with 39 (41.9%), union EB cases with 8 (8.6%) and Kindler syndrome with 4 (4.3%) cases. The clinical form could not be identified in a case. A total of 48 cases (51.6%) came from Lima and Callao, and 45 cases (48.4%) from other provinces of the country. Extracutaneous manifestations involved gastrointestinal (44.1%), ocular (37.6%), odontogenic (87.1%), and nutritional (79.6%) involvement, as well as pseudosindactilia (16.1%). Chronic malnutrition (71.6%), acute malnutrition (17.6%) and anemia (62.4%) were found. Mortality corresponded to 6 cases (6.5%). 93 cases of EB were reported in INSN, the predominant clinical presentation was the dystrophic form.

Correction of dog dystrophic epidermolysis bullosa by transplantation of genetically modified epidermal autografts.

PubMed

Gache, Yannick; Pin, Didier; Gagnoux-Palacios, Laurent; Carozzo, Claude; Meneguzzi, Guerrino

2011-10-01

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe skin blistering condition caused by mutations in the gene coding for collagen type VII. Genetically engineered RDEB dog keratinocytes were used to generate autologous epidermal sheets subsequently grafted on two RDEB dogs carrying a homozygous missense mutation in the col7a1 gene and expressing baseline amounts of the aberrant protein. Transplanted cells regenerated a differentiated and vascularized auto-renewing epidermis progressively repopulated by dendritic cells and melanocytes. No adverse immune reaction was detected in either dog. In dog 1, the grafted epidermis firmly adhered to the dermis throughout the 24-month follow-up, which correlated with efficient transduction (100%) of highly clonogenic epithelial cells and sustained transgene expression. In dog 2, less efficient (65%) transduction of primary keratinocytes resulted in a loss of the transplanted epidermis and graft blistering 5 months after transplantation. These data provide the proof of principle for ex vivo gene therapy of RDEB patients with missense mutations in collagen type VII by engraftment of the reconstructed epidermis, and demonstrate that highly efficient transduction of epidermal stem cells is crucial for successful gene therapy of inherited skin diseases in which correction of the genetic defect confers no major selective advantage in cell culture.

Site-specific genome editing for correction of induced pluripotent stem cells derived from dominant dystrophic epidermolysis bullosa.

PubMed

Shinkuma, Satoru; Guo, Zongyou; Christiano, Angela M

2016-05-17

Genome editing with engineered site-specific endonucleases involves nonhomologous end-joining, leading to reading frame disruption. The approach is applicable to dominant negative disorders, which can be treated simply by knocking out the mutant allele, while leaving the normal allele intact. We applied this strategy to dominant dystrophic epidermolysis bullosa (DDEB), which is caused by a dominant negative mutation in the COL7A1 gene encoding type VII collagen (COL7). We performed genome editing with TALENs and CRISPR/Cas9 targeting the mutation, c.8068_8084delinsGA. We then cotransfected Cas9 and guide RNA expression vectors expressed with GFP and DsRed, respectively, into induced pluripotent stem cells (iPSCs) generated from DDEB fibroblasts. After sorting, 90% of the iPSCs were edited, and we selected four gene-edited iPSC lines for further study. These iPSCs were differentiated into keratinocytes and fibroblasts secreting COL7. RT-PCR and Western blot analyses revealed gene-edited COL7 with frameshift mutations degraded at the protein level. In addition, we confirmed that the gene-edited truncated COL7 could neither associate with normal COL7 nor undergo triple helix formation. Our data establish the feasibility of mutation site-specific genome editing in dominant negative disorders.

Scrotal calcinosis: idiopathic or dystrophic?

PubMed

Dubey, Suparna; Sharma, Rajeev; Maheshwari, Veena

2010-02-15

Scrotal calcinosis is a rare benign local process characterized by multiple, painless, hard scrotal nodules in the absence of any systemic metabolic disorder. Histological examination reveals extensive deposition of calcium in the dermis, which may be surrounded by histiocytes and an inflammatory giant cell reaction. Numerous theories have been propounded to explain the pathogenesis of this condition, but the principal debate revolves around whether the calcium is deposited at the site of previous epithelial cysts or the calcified nodules are purely idiopathic. This is the largest study of scrotal calcinosis to date with 100 cases, on which clinical, biochemical, radiological, cytopathological, and histopathological examinations were conducted. The histological picture shows a continuous spectrum of changes ranging from intact epithelial cysts (41.0%) - both normal and inflamed; through inflamed cysts containing calcific material in the lumen but with intact cyst wall (53.0%); calcified inflamed cysts with partial epithelial lining (11.0%); to 'naked' calcium deposits lying in the dermis (100%), sometimes compressing surrounding collagen fibres to form a pseudocyst (56.0%). The presence of normal values of calcium and phosphorus along with this spectrum of changes in histology both support the theory that these form by dystrophic calcification of epithelial cysts in a progression that involves inflammation, rupture, calcification and obliteration of the cyst wall.

Syngeneic Schwann cell transplantation preserves vision in RCS rat without immunosuppression.

PubMed

McGill, Trevor J; Lund, Raymond D; Douglas, Robert M; Wang, Shaomei; Lu, Bin; Silver, Byron D; Secretan, Matt R; Arthur, Jennifer N; Prusky, Glen T

2007-04-01

To evaluate the efficacy of immunologically compatible Schwann cells transplanted without immunosuppression in the RCS rat retina to preserve vision. Syngeneic (dystrophic RCS) Schwann cells harvested from sciatic nerves were cultured and transplanted into one eye of dystrophic RCS rats at an early stage of retinal degeneration. Allogeneic (Long-Evans) Schwann cells and unoperated eyes served as controls. Vision through transplanted and unoperated eyes was then quantified using two visual behavior tasks, one measuring the spatial frequency and contrast sensitivity thresholds of the optokinetic response (OKR) and the other measuring grating acuity in a perception task. Spatial frequency thresholds measured through syngeneically transplanted eyes maintained near normal spatial frequency sensitivity for approximately 30 weeks, whereas thresholds through control eyes deteriorated to less than 20% of normal over the same period. Contrast sensitivity was preserved through syngeneically transplanted eyes better than through allogeneic and unoperated eyes, at all spatial frequencies. Grating acuity measured through syngeneically transplanted eyes was maintained at approximately 60% of normal, whereas acuity of allogeneically transplanted eyes was significantly lower at approximately 40% of normal. The ability of immunoprivileged Schwann cell transplants to preserve vision in RCS rats indicates that transplantation of syngeneic Schwann cells holds promise as a preventive treatment for retinal degenerative disease.

Axial stretch-dependent cation entry in dystrophic cardiomyopathy: Involvement of several TRPs channels

PubMed Central

Krzesiak, A.; Lipskaia, L.; Adnot, S.; Hajjar, R.J.; Cognard, C.

2016-01-01

In Duchenne muscular dystrophy (DMD), deficiency of the cytoskeletal protein dystrophin leads to well-described defects in skeletal muscle but also to dilated cardiomyopathy (DCM). In cardiac cells, the subsarcolemmal localization of dystrophin is thought to protect the membrane from mechanical stress. The dystrophin deficiency leads to membrane instability and a high stress-induced Ca2+ influx due to dysregulation of sarcolemmal channels such as stretch-activated channels (SACs). In this work divalent cation entry has been explored in isolated ventricular Wild Type (WT) and mdx cardiomyocytes in two different conditions: at rest and during the application of an axial stretch. At rest, our results suggest that activation of TRPV2 channels participates to a constitutive basal cation entry in mdx cardiomyocytes.Using microcarbon fibres technique, an axial stretchwas applied to mimic effects of physiological conditions of ventricular filling and study on cation influx bythe Mn2+-quenching techniquedemonstrated a high stretch-dependentcationic influx in dystrophic cells, partially due to SACs. Involvement of TRPs channels in this excessive Ca2+ influx has been investigated using specific modulators and demonstratedboth sarcolemmal localization and an abnormal activity of TRPV2 channels. In conclusion, TRPV2 channels are demonstrated here to play a key role in cation influx and dysregulation in dystrophin deficient cardiomyocytes, enhanced in stretching conditions. PMID:26803937

Behavioral phenotypes of genetic mouse models of autism

PubMed Central

Kazdoba, T. M.; Leach, P. T.; Crawley, J. N.

2016-01-01

More than a hundred de novo single gene mutations and copy-number variants have been implicated in autism, each occurring in a small subset of cases. Mutant mouse models with syntenic mutations offer research tools to gain an understanding of the role of each gene in modulating biological and behavioral phenotypes relevant to autism. Knockout, knockin and transgenic mice incorporating risk gene mutations detected in autism spectrum disorder and comorbid neurodevelopmental disorders are now widely available. At present, autism spectrum disorder is diagnosed solely by behavioral criteria. We developed a constellation of mouse behavioral assays designed to maximize face validity to the types of social deficits and repetitive behaviors that are central to an autism diagnosis. Mouse behavioral assays for associated symptoms of autism, which include cognitive inflexibility, anxiety, hyperactivity, and unusual reactivity to sensory stimuli, are frequently included in the phenotypic analyses. Over the past 10 years, we and many other laboratories around the world have employed these and additional behavioral tests to phenotype a large number of mutant mouse models of autism. In this review, we highlight mouse models with mutations in genes that have been identified as risk genes for autism, which work through synaptic mechanisms and through the mTOR signaling pathway. Robust, replicated autism-relevant behavioral outcomes in a genetic mouse model lend credence to a causal role for specific gene contributions and downstream biological mechanisms in the etiology of autism. PMID:26403076

Defining the role of polyamines in colon carcinogenesis using mouse models

PubMed Central

Ignatenko, Natalia A.; Gerner, Eugene W.; Besselsen, David G.

2011-01-01

Genetics and diet are both considered important risk determinants for colorectal cancer, a leading cause of death in the US and worldwide. Genetically engineered mouse (GEM) models have made a significant contribution to the characterization of colorectal cancer risk factors. Reliable, reproducible, and clinically relevant animal models help in the identification of the molecular events associated with disease progression and in the development of effictive treatment strategies. This review is focused on the use of mouse models for studying the role of polyamines in colon carcinogenesis. We describe how the available mouse models of colon cancer such as the multiple intestinal neoplasia (Min) mice and knockout genetic models facilitate understanding of the role of polyamines in colon carcinogenesis and help in the development of a rational strategy for colon cancer chemoprevention. PMID:21712957

Targeting Cancer Protein Profiles with Split-Enzyme Reporter Fragments to Achieve Chemical Resolution for Molecular Imaging

DTIC Science & Technology

2013-08-01

We next tested the utility of the construct to accumulate in tumors expressing EGFR using an orthotopic mouse model for brain tumors. Glioma cells...filament tumor marker, identified implanted cells within the orthotopic mouse model which were of human origin, i.e. Gli36Δ5 cells, and demonstrated that...forward into in vivo animal tumor model studies. • In vivo imaging of EGFR targeted-complex in orthotopic mouse model of brain tumor. • Ex vivo validation

Genetically engineered mouse models of melanoma.

PubMed

Pérez-Guijarro, Eva; Day, Chi-Ping; Merlino, Glenn; Zaidi, M Raza

2017-06-01

Melanoma is a complex disease that exhibits highly heterogeneous etiological, histopathological, and genetic features, as well as therapeutic responses. Genetically engineered mouse (GEM) models provide powerful tools to unravel the molecular mechanisms critical for melanoma development and drug resistance. Here, we expound briefly the basis of the mouse modeling design, the available technology for genetic engineering, and the aspects influencing the use of GEMs to model melanoma. Furthermore, we describe in detail the currently available GEM models of melanoma. Cancer 2017;123:2089-103. © 2017 American Cancer Society. © 2017 American Cancer Society.

CRISPR-Mediated Knockout of Cybb in NSG Mice Establishes a Model of Chronic Granulomatous Disease for Human Stem-Cell Gene Therapy Transplants.

PubMed

Sweeney, Colin L; Choi, Uimook; Liu, Chengyu; Koontz, Sherry; Ha, Seung-Kwon; Malech, Harry L

2017-07-01

Chronic granulomatous disease (CGD) is characterized by defects in the production of microbicidal reactive oxygen species (ROS) by phagocytes. Testing of gene and cell therapies for the treatment of CGD in human hematopoietic cells requires preclinical transplant models. The use of the lymphocyte-deficient NOD.Cg-Prkdc scid Il2rg tm1Wjl/ SzJ (NSG) mouse strain for human hematopoietic cell xenografts to test CGD therapies is complicated by the presence of functional mouse granulocytes capable of producing ROS for subsequent bacterial and fungal killing. To establish a phagocyte-defective mouse model of X-linked CGD (X-CGD) in NSG mice, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 was utilized for targeted knockout of mouse Cybb on the X-chromosome by microinjection of NSG mouse zygotes with Cas9 mRNA and CRISPR single-guide RNA targeting Cybb exon 1 or exon 3. This resulted in a high incidence of indel formation at the CRISPR target site, with all mice exhibiting deletions in at least one Cybb allele based on sequence analysis of tail snip DNA. A female mouse heterozygous for a 235-bp deletion in Cybb exon 1 was bred to an NSG male to establish the X-CGD NSG mouse strain, NSG.Cybb[KO]. Resulting male offspring with the 235 bp deletion were found to be defective for production of ROS by neutrophils and other phagocytes, and demonstrated increased susceptibility to spontaneous bacterial and fungal infections with granulomatous inflammation. The establishment of the phagocyte-defective NSG.Cybb[KO] mouse model enables the in vivo assessment of gene and cell therapy strategies for treating CGD in human hematopoietic cell transplants without obfuscation by functional mouse phagocytes, and may also be useful for modeling other phagocyte disorders in humanized NSG mouse xenografts.

Antibody-directed myostatin inhibition improves diaphragm pathology in young but not adult dystrophic mdx mice.

PubMed

Murphy, Kate T; Ryall, James G; Snell, Sarah M; Nair, Lawrence; Koopman, René; Krasney, Philip A; Ibebunjo, Chikwendu; Holden, Kathryn S; Loria, Paula M; Salatto, Christopher T; Lynch, Gordon S

2010-05-01

Duchenne muscular dystrophy (DMD) is characterized by progressive skeletal muscle wasting and weakness, leading to premature death from respiratory and/or cardiac failure. A clinically relevant question is whether myostatin inhibition can improve function of the diaphragm, which exhibits a severe and progressive pathology comparable with that in DMD. We hypothesized that antibody-directed myostatin inhibition would improve the pathophysiology of diaphragm muscle strips from young mdx mice (when the pathology is mild) and adult mdx mice (when the pathology is quite marked). Five weeks treatment with a mouse chimera of anti-human myostatin antibody (PF-354, 10 mg/kg/week) increased muscle mass (P < 0.05) and increased diaphragm median fiber cross-sectional area (CSA, P < 0.05) in young C57BL/10 and mdx mice, compared with saline-treated controls. PF-354 had no effect on specific force (sPo, maximum force normalized to muscle CSA) of diaphragm muscle strips from young C57BL/10 mice, but increased sPo by 84% (P < 0.05) in young mdx mice. In contrast, 8 weeks of PF-354 treatment did not improve muscle mass, median fiber CSA, collagen infiltration, or sPo of diaphragm muscle strips from adult mdx mice. PF-354 antibody-directed myostatin inhibition completely restored the functional capacity of diaphragm strips to control levels when treatment was initiated early, but not in the later stages of disease progression, suggesting that such therapies may only have a limited window of efficacy for DMD and related conditions.

Genetically engineered mouse models of craniopharyngioma: an opportunity for therapy development and understanding of tumor biology.

PubMed

Apps, John Richard; Martinez-Barbera, Juan Pedro

2017-05-01

Adamantinomatous craniopharyngioma (ACP) is the commonest tumor of the sellar region in childhood. Two genetically engineered mouse models have been developed and are giving valuable insights into ACP biology. These models have identified novel pathways activated in tumors, revealed an important function of paracrine signalling and extended conventional theories about the role of organ-specific stem cells in tumorigenesis. In this review, we summarize these mouse models, what has been learnt, their limitations and open questions for future research. We then discussed how these mouse models may be used to test novel therapeutics against potentially targetable pathways recently identified in human ACP. © 2017 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.

Compensatory Limb Use and Behavioral Assessment of Motor Skill Learning Following Sensorimotor Cortex Injury in a Mouse Model of Ischemic Stroke

PubMed Central

Kerr, Abigail L.; Tennant, Kelly A.

2014-01-01

Mouse models have become increasingly popular in the field of behavioral neuroscience, and specifically in studies of experimental stroke. As models advance, it is important to develop sensitive behavioral measures specific to the mouse. The present protocol describes a skilled motor task for use in mouse models of stroke. The Pasta Matrix Reaching Task functions as a versatile and sensitive behavioral assay that permits experimenters to collect accurate outcome data and manipulate limb use to mimic human clinical phenomena including compensatory strategies (i.e., learned non-use) and focused rehabilitative training. When combined with neuroanatomical tools, this task also permits researchers to explore the mechanisms that support behavioral recovery of function (or lack thereof) following stroke. The task is both simple and affordable to set up and conduct, offering a variety of training and testing options for numerous research questions concerning functional outcome following injury. Though the task has been applied to mouse models of stroke, it may also be beneficial in studies of functional outcome in other upper extremity injury models. PMID:25045916

Validation of ultrasonography for non-invasive assessment of diaphragm function in muscular dystrophy.

PubMed

Whitehead, Nicholas P; Bible, Kenneth L; Kim, Min Jeong; Odom, Guy L; Adams, Marvin E; Froehner, Stanley C

2016-12-15

Duchenne muscular dystrophy (DMD) is a severe, degenerative muscle disease that is commonly studied using the mdx mouse. The mdx diaphragm muscle closely mimics the pathophysiological changes in DMD muscles. mdx diaphragm force is commonly assessed ex vivo, precluding time course studies. Here we used ultrasonography to evaluate time-dependent changes in diaphragm function in vivo, by measuring diaphragm movement amplitude. In mdx mice, diaphragm amplitude decreased with age and values were much lower than for wild-type mice. Importantly, diaphragm amplitude strongly correlated with ex vivo specific force values. Micro-dystrophin administration increased mdx diaphragm amplitude by 26% after 4 weeks. Diaphragm amplitude correlated positively with ex vivo force values and negatively with diaphragm fibrosis, a major cause of DMD muscle weakness. These studies validate diaphragm ultrasonography as a reliable technique for assessing time-dependent changes in mdx diaphragm function in vivo. This technique will be valuable for testing potential therapies for DMD. Duchenne muscular dystrophy (DMD) is a severe, degenerative muscle disease caused by dystrophin mutations. The mdx mouse is a widely used animal model of DMD. The mdx diaphragm muscle most closely recapitulates key features of DMD muscles, including progressive fibrosis and considerable force loss. Diaphragm function in mdx mice is commonly evaluated by specific force measurements ex vivo. While useful, this method only measures force from a small muscle sample at one time point. Therefore, accurate assessment of diaphragm function in vivo would provide an important advance to study the time course of functional decline and treatment benefits. Here, we evaluated an ultrasonography technique for measuring time-dependent changes of diaphragm function in mdx mice. Diaphragm movement amplitude values for mdx mice were considerably lower than those for wild-type, decreased from 8 to 18 months of age, and correlated strongly with ex vivo specific force. We then investigated the time course of diaphragm amplitude changes following administration of an adeno-associated viral vector expressing Flag-micro-dystrophin (AAV-μDys) to young adult mdx mice. Diaphragm amplitude peaked 4 weeks after AAV-μDys administration, and was 26% greater than control mdx mice at this time. This value decreased slightly to 21% above mdx controls after 12 weeks of treatment. Importantly, diaphragm amplitude again correlated strongly with ex vivo specific force. Also, diaphragm amplitude and specific force negatively correlated with fibrosis levels in the muscle. Together, our results validate diaphragm ultrasonography as a reliable technique for assessing time-dependent changes in dystrophic diaphragm function in vivo, and for evaluating potential therapies for DMD. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Validation of ultrasonography for non‐invasive assessment of diaphragm function in muscular dystrophy

PubMed Central

Bible, Kenneth L.; Kim, Min Jeong; Odom, Guy L.; Adams, Marvin E.; Froehner, Stanley C.

2016-01-01

Key points Duchenne muscular dystrophy (DMD) is a severe, degenerative muscle disease that is commonly studied using the mdx mouse. The mdx diaphragm muscle closely mimics the pathophysiological changes in DMD muscles. mdx diaphragm force is commonly assessed ex vivo, precluding time course studies. Here we used ultrasonography to evaluate time‐dependent changes in diaphragm function in vivo, by measuring diaphragm movement amplitude.In mdx mice, diaphragm amplitude decreased with age and values were much lower than for wild‐type mice. Importantly, diaphragm amplitude strongly correlated with ex vivo specific force values.Micro‐dystrophin administration increased mdx diaphragm amplitude by 26% after 4 weeks. Diaphragm amplitude correlated positively with ex vivo force values and negatively with diaphragm fibrosis, a major cause of DMD muscle weakness.These studies validate diaphragm ultrasonography as a reliable technique for assessing time‐dependent changes in mdx diaphragm function in vivo. This technique will be valuable for testing potential therapies for DMD. Abstract Duchenne muscular dystrophy (DMD) is a severe, degenerative muscle disease caused by dystrophin mutations. The mdx mouse is a widely used animal model of DMD. The mdx diaphragm muscle most closely recapitulates key features of DMD muscles, including progressive fibrosis and considerable force loss. Diaphragm function in mdx mice is commonly evaluated by specific force measurements ex vivo. While useful, this method only measures force from a small muscle sample at one time point. Therefore, accurate assessment of diaphragm function in vivo would provide an important advance to study the time course of functional decline and treatment benefits. Here, we evaluated an ultrasonography technique for measuring time‐dependent changes of diaphragm function in mdx mice. Diaphragm movement amplitude values for mdx mice were considerably lower than those for wild‐type, decreased from 8 to 18 months of age, and correlated strongly with ex vivo specific force. We then investigated the time course of diaphragm amplitude changes following administration of an adeno‐associated viral vector expressing Flag‐micro‐dystrophin (AAV‐μDys) to young adult mdx mice. Diaphragm amplitude peaked 4 weeks after AAV‐μDys administration, and was 26% greater than control mdx mice at this time. This value decreased slightly to 21% above mdx controls after 12 weeks of treatment. Importantly, diaphragm amplitude again correlated strongly with ex vivo specific force. Also, diaphragm amplitude and specific force negatively correlated with fibrosis levels in the muscle. Together, our results validate diaphragm ultrasonography as a reliable technique for assessing time‐dependent changes in dystrophic diaphragm function in vivo, and for evaluating potential therapies for DMD. PMID:27570057

A comparison of some organizational characteristics of the mouse central retina and the human macula.

PubMed

Volland, Stefanie; Esteve-Rudd, Julian; Hoo, Juyea; Yee, Claudine; Williams, David S

2015-01-01

Mouse models have greatly assisted our understanding of retinal degenerations. However, the mouse retina does not have a macula, leading to the question of whether the mouse is a relevant model for macular degeneration. In the present study, a quantitative comparison between the organization of the central mouse retina and the human macula was made, focusing on some structural characteristics that have been suggested to be important in predisposing the macula to stresses leading to degeneration: photoreceptor density, phagocytic load on the RPE, and the relative thinness of Bruch's membrane. Light and electron microscopy measurements from retinas of two strains of mice, together with published data on human retinas, were used for calculations and subsequent comparisons. As in the human retina, the central region of the mouse retina possesses a higher photoreceptor cell density and a thinner Bruch's membrane than in the periphery; however, the magnitudes of these periphery to center gradients are larger in the human. Of potentially greater relevance is the actual photoreceptor cell density, which is much greater in the mouse central retina than in the human macula, underlying a higher phagocytic load for the mouse RPE. Moreover, at eccentricities that correspond to the peripheral half of the human macula, the rod to cone ratio is similar between mouse and human. Hence, with respect to photoreceptor density and phagocytic load of the RPE, the central mouse retina models at least the more peripheral part of the macula, where macular degeneration is often first evident.

A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN

DTIC Science & Technology

2014-09-01

AWARD NUMBER: W81XWH-13-1-0220 TITLE: A Genetically Engineered Mouse Model of Neuroblastoma ...CONTRACT NUMBER A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN 5b. GRANT NUMBER W81XWH-13-1-0220 5c...common ALK mutations in neuroblastoma , F1174L and R1275Q. We have determined that in tumors cells expressing mutated ALK, different downstream

Developing Novel Therapeutic Approaches in Small Cell Lung Carcinoma Using Genetically Engineered Mouse Models and Human Circulating Tumor Cells

DTIC Science & Technology

2014-10-01

AD_________________ Award Number: W81XWH-13-1-0325 TITLE: Developing Novel Therapeutic Approaches in Small Cell Lung Carcinoma Using ...Genetically Engineered Mouse Models and Human Circulating Tumor Cells PRINCIPAL INVESTIGATOR: Jeffrey Engelman MD PhD CONTRACTING ORGANIZATION ...Novel Therapeutic Approaches in Small Cell Lung 5a. CONTRACT NUMBER W81XWH-13-1-0325 Carcinoma Using Genetically Engineered Mouse Models and 5b

Behavioural phenotyping assays for mouse models of autism

PubMed Central

Silverman, Jill L.; Yang, Mu; Lord, Catherine; Crawley, Jacqueline N.

2011-01-01

Autism is a heterogeneous neurodevelopmental disorder of unknown aetiology that affects 1 in 100–150 individuals. Diagnosis is based on three categories of behavioural criteria: abnormal social interactions, communication deficits and repetitive behaviours. Strong evidence for a genetic basis has prompted the development of mouse models with targeted mutations in candidate genes for autism. As the diagnostic criteria for autism are behavioural, phenotyping these mouse models requires behavioural assays with high relevance to each category of the diagnostic symptoms. Behavioural neuroscientists are generating a comprehensive set of assays for social interaction, communication and repetitive behaviours to test hypotheses about the causes of austism. Robust phenotypes in mouse models hold great promise as translational tools for discovering effective treatments for components of autism spectrum disorders. PMID:20559336

Using animal models to determine the significance of complement activation in Alzheimer's disease

PubMed Central

Loeffler, David A

2004-01-01

Complement inflammation is a major inflammatory mechanism whose function is to promote the removal of microorganisms and the processing of immune complexes. Numerous studies have provided evidence for an increase in this process in areas of pathology in the Alzheimer's disease (AD) brain. Because complement activation proteins have been demonstrated in vitro to exert both neuroprotective and neurotoxic effects, the significance of this process in the development and progression of AD is unclear. Studies in animal models of AD, in which brain complement activation can be experimentally altered, should be of value for clarifying this issue. However, surprisingly little is known about complement activation in the transgenic animal models that are popular for studying this disorder. An optimal animal model for studying the significance of complement activation on Alzheimer's – related neuropathology should have complete complement activation associated with senile plaques, neurofibrillary tangles (if present), and dystrophic neurites. Other desirable features include both classical and alternative pathway activation, increased neuronal synthesis of native complement proteins, and evidence for an increase in complement activation prior to the development of extensive pathology. In order to determine the suitability of different animal models for studying the role of complement activation in AD, the extent of complement activation and its association with neuropathology in these models must be understood. PMID:15479474

A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webb, Carol F., E-mail: carol-webb@omrf.org; Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK

Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights:more » • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.« less

Mouse phenotyping.

PubMed

Fuchs, Helmut; Gailus-Durner, Valérie; Adler, Thure; Aguilar-Pimentel, Juan Antonio; Becker, Lore; Calzada-Wack, Julia; Da Silva-Buttkus, Patricia; Neff, Frauke; Götz, Alexander; Hans, Wolfgang; Hölter, Sabine M; Horsch, Marion; Kastenmüller, Gabi; Kemter, Elisabeth; Lengger, Christoph; Maier, Holger; Matloka, Mikolaj; Möller, Gabriele; Naton, Beatrix; Prehn, Cornelia; Puk, Oliver; Rácz, Ildikó; Rathkolb, Birgit; Römisch-Margl, Werner; Rozman, Jan; Wang-Sattler, Rui; Schrewe, Anja; Stöger, Claudia; Tost, Monica; Adamski, Jerzy; Aigner, Bernhard; Beckers, Johannes; Behrendt, Heidrun; Busch, Dirk H; Esposito, Irene; Graw, Jochen; Illig, Thomas; Ivandic, Boris; Klingenspor, Martin; Klopstock, Thomas; Kremmer, Elisabeth; Mempel, Martin; Neschen, Susanne; Ollert, Markus; Schulz, Holger; Suhre, Karsten; Wolf, Eckhard; Wurst, Wolfgang; Zimmer, Andreas; Hrabě de Angelis, Martin

2011-02-01

Model organisms like the mouse are important tools to learn more about gene function in man. Within the last 20 years many mutant mouse lines have been generated by different methods such as ENU mutagenesis, constitutive and conditional knock-out approaches, knock-down, introduction of human genes, and knock-in techniques, thus creating models which mimic human conditions. Due to pleiotropic effects, one gene may have different functions in different organ systems or time points during development. Therefore mutant mouse lines have to be phenotyped comprehensively in a highly standardized manner to enable the detection of phenotypes which might otherwise remain hidden. The German Mouse Clinic (GMC) has been established at the Helmholtz Zentrum München as a phenotyping platform with open access to the scientific community (www.mousclinic.de; [1]). The GMC is a member of the EUMODIC consortium which created the European standard workflow EMPReSSslim for the systemic phenotyping of mouse models (http://www.eumodic.org/[2]). Copyright © 2010 Elsevier Inc. All rights reserved.

Human androgen deficiency: insights gained from androgen receptor knockout mouse models

PubMed Central

Rana, Kesha; Davey, Rachel A; Zajac, Jeffrey D

2014-01-01

The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor (AR) through the use of genetically modified mouse models. A number of global and tissue-specific AR knockout (ARKO) models have been generated using the Cre-loxP system which allows tissue- and/or cell-specific deletion. These ARKO models have examined a number of sites of androgen action including the cardiovascular system, the immune and hemopoetic system, bone, muscle, adipose tissue, the prostate and the brain. This review focuses on the insights that have been gained into human androgen deficiency through the use of ARKO mouse models at each of these sites of action, and highlights the strengths and limitations of these Cre-loxP mouse models that should be considered to ensure accurate interpretation of the phenotype. PMID:24480924

Modelling clinical systemic lupus erythematosus: similarities, differences and success stories

PubMed Central

Celhar, Teja

2017-01-01

Abstract Mouse models of SLE have been indispensable tools to study disease pathogenesis, to identify genetic susceptibility loci and targets for drug development, and for preclinical testing of novel therapeutics. Recent insights into immunological mechanisms of disease progression have boosted a revival in SLE drug development. Despite promising results in mouse studies, many novel drugs have failed to meet clinical end points. This is probably because of the complexity of the disease, which is driven by polygenic predisposition and diverse environmental factors, resulting in a heterogeneous clinical presentation. Each mouse model recapitulates limited aspects of lupus, especially in terms of the mechanism underlying disease progression. The main mouse models have been fairly successful for the evaluation of broad-acting immunosuppressants. However, the advent of targeted therapeutics calls for a selection of the most appropriate model(s) for testing and, ultimately, identification of patients who will be most likely to respond. PMID:28013204

Mouse Models of Gastric Cancer

PubMed Central

Hayakawa, Yoku; Fox, James G.; Gonda, Tamas; Worthley, Daniel L.; Muthupalani, Sureshkumar; Wang, Timothy C.

2013-01-01

Animal models have greatly enriched our understanding of the molecular mechanisms of numerous types of cancers. Gastric cancer is one of the most common cancers worldwide, with a poor prognosis and high incidence of drug-resistance. However, most inbred strains of mice have proven resistant to gastric carcinogenesis. To establish useful models which mimic human gastric cancer phenotypes, investigators have utilized animals infected with Helicobacter species and treated with carcinogens. In addition, by exploiting genetic engineering, a variety of transgenic and knockout mouse models of gastric cancer have emerged, such as INS-GAS mice and TFF1 knockout mice. Investigators have used the combination of carcinogens and gene alteration to accelerate gastric cancer development, but rarely do mouse models show an aggressive and metastatic gastric cancer phenotype that could be relevant to preclinical studies, which may require more specific targeting of gastric progenitor cells. Here, we review current gastric carcinogenesis mouse models and provide our future perspectives on this field. PMID:24216700

Phenotyping male infertility in the mouse: how to get the most out of a 'non-performer'.

PubMed

Borg, Claire L; Wolski, Katja M; Gibbs, Gerard M; O'Bryan, Moira K

2010-01-01

Functional male gametes are produced through complex processes that take place within the testis, epididymis and female reproductive tract. A breakdown at any of these phases can result in male infertility. The production of mutant mouse models often yields an unexpected male infertility phenotype. It is with this in mind that the current review has been written. The review aims to act as a guide to the 'non-reproductive biologist' to facilitate a systematic analysis of sterile or subfertile mice and to assist in extracting the maximum amount of information from each model. This is a review of the original literature on defects in the processes that take a mouse spermatogonial stem cell through to a fully functional spermatozoon, which result in male infertility. Based on literature searches and personal experience, we have outlined a step-by-step strategy for the analysis of an infertile male mouse line. A wide range of methods can be used to define the phenotype of an infertile male mouse. These methods range from histological methods such as electron microscopy and immunohistochemistry, to hormone analyses and methods to assess sperm maturation status and functional competence. With the increased rate of genetically modified mouse production, the generation of mouse models with unexpected male infertility is increasing. This manuscript will help to ensure that the maximum amount of information is obtained from each mouse model and, by extension, will facilitate the knowledge of both normal fertility processes and the causes of human infertility.

A surgical approach appropriate for targeted cochlear gene therapy in the mouse.

PubMed

Jero, J; Tseng, C J; Mhatre, A N; Lalwani, A K

2001-01-01

Therapeutic manipulations of the mammalian cochlea, including cochlear gene transfer, have been predominantly studied using the guinea pig as the experimental model. With the significant developments in mouse genomics and the availability of mutant strains of mice with well-characterized hearing loss, the mouse justifiably will be the preferred animal model for therapeutic manipulations. However, the potential advantages of the mouse model have not been fully realized due to the surgical difficulty of accessing its small cochlea. This study describes a ventral approach, instead of the routinely used postauricular approach in other rodents, for accessing the mouse middle and inner ear, and its application in cochlear gene transfer. This ventral approach enabled rapid and direct delivery of liposome-transgene complex to the mouse inner ear while avoiding blood loss, facial nerve morbidity, and mortality. Transgene expression at 3 days was detected in Reissner's membrane, spiral limbus, spiral ligament, and spiral ganglion cells, in a pattern similar to that previously described in the guinea pig. The successful access and delivery of material to the mouse cochlea and the replication of gene expression seen in the guinea pig demonstrated in this study should promote the use of the mouse in future studies investigating targeted cochlear therapy.

A Special Population of Regulatory T Cells Potentiates Muscle Repair

PubMed Central

Burzyn, Dalia; Kuswanto, Wilson; Kolodin, Dmitriy; Shadrach, Jennifer L.; Cerletti, Massimiliano; Jang, Young; Sefik, Esen; Tan, Tze Guan; Wagers, Amy J.; Benoist, Christophe; Mathis, Diane

2014-01-01

SUMMARY Long recognized to be potent suppressors of immune responses, Foxp3+CD4+ regulatory T (Treg) cells are being rediscovered as regulators of nonimmunological processes. We describe a phenotypically and functionally distinct population of Treg cells that rapidly accumulated in the acutely injured skeletal muscle of mice, just as invading myeloidlineage cells switched from a proinflammatory to a proregenerative state. A Treg population of similar phenotype accumulated in muscles of genetically dystrophic mice. Punctual depletion of Treg cells during the repair process prolonged the proinflammatory infiltrate and impaired muscle repair, while treatments that increased or decreased Treg activities diminished or enhanced (respectively) muscle damage in a dystrophy model. Muscle Treg cells expressed the growth factor Amphiregulin, which acted directly on muscle satellite cells in vitro and improved muscle repair in vivo. Thus, Treg cells and their products may provide new therapeutic opportunities for wound repair and muscular dystrophies. PMID:24315098

Wasting Mechanisms in Muscular Dystrophy

PubMed Central

Shin, Jonghyun; Tajrishi, Marjan M.; Ogura, Yuji; Kumar, Ashok

2013-01-01

Muscular dystrophy is a group of more than 30 different clinical genetic disorders that are characterized by progressive skeletal muscle wasting and degeneration. Primary deficiency of specific extracellular matrix, sarcoplasmic, cytoskeletal, or nuclear membrane protein results in several secondary changes such as sarcolemmal instability, calcium influx, fiber necrosis, oxidative stress, inflammatory response, breakdown of extracellular matrix, and eventually fibrosis which leads to loss of ambulance and cardiac and respiratory failure. A number of molecular processes have now been identified which hasten disease progression in human patients and animal models of muscular dystrophy. Accumulating evidence further suggests that aberrant activation of several signaling pathways aggravate pathological cascades in dystrophic muscle. Although replacement of defective gene with wild-type is paramount to cure, management of secondary pathological changes has enormous potential to improving the quality of life and extending lifespan of muscular dystrophy patients. In this article, we have reviewed major cellular and molecular mechanisms leading to muscle wasting in muscular dystrophy. PMID:23669245

Behavioral phenotypes of genetic mouse models of autism.

PubMed

Kazdoba, T M; Leach, P T; Crawley, J N

2016-01-01

More than a hundred de novo single gene mutations and copy-number variants have been implicated in autism, each occurring in a small subset of cases. Mutant mouse models with syntenic mutations offer research tools to gain an understanding of the role of each gene in modulating biological and behavioral phenotypes relevant to autism. Knockout, knockin and transgenic mice incorporating risk gene mutations detected in autism spectrum disorder and comorbid neurodevelopmental disorders are now widely available. At present, autism spectrum disorder is diagnosed solely by behavioral criteria. We developed a constellation of mouse behavioral assays designed to maximize face validity to the types of social deficits and repetitive behaviors that are central to an autism diagnosis. Mouse behavioral assays for associated symptoms of autism, which include cognitive inflexibility, anxiety, hyperactivity, and unusual reactivity to sensory stimuli, are frequently included in the phenotypic analyses. Over the past 10 years, we and many other laboratories around the world have employed these and additional behavioral tests to phenotype a large number of mutant mouse models of autism. In this review, we highlight mouse models with mutations in genes that have been identified as risk genes for autism, which work through synaptic mechanisms and through the mTOR signaling pathway. Robust, replicated autism-relevant behavioral outcomes in a genetic mouse model lend credence to a causal role for specific gene contributions and downstream biological mechanisms in the etiology of autism. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Using Genetic Mouse Models to Gain Insight into Glaucoma: Past Results and Future Possibilities

PubMed Central

Fernandes, Kimberly A.; Harder, Jeffrey M.; Williams, Pete A.; Rausch, Rebecca L.; Kiernan, Amy E.; Nair, K. Saidas; Anderson, Michael G.; John, Simon W.; Howell, Gareth R.; Libby, Richard T.

2015-01-01

While all forms of glaucoma are characterized by a specific pattern of retinal ganglion cell death, they are clinically divided into several distinct subclasses, including normal tension glaucoma, primary open angle glaucoma, congenital glaucoma, and secondary glaucoma. For each type of glaucoma there are likely numerous molecular pathways that control susceptibility to the disease. Given this complexity, a single animal model will never precisely model all aspects of all the different types of human glaucoma. Therefore, multiple animal models have been utilized to study glaucoma but more are needed. Because of the powerful genetic tools available to use in the laboratory mouse, it has proven to be a highly useful mammalian system for studying the pathophysiology of human disease. The similarity between human and mouse eyes coupled with the ability to use a combination of advanced cell biological and genetic tools in mice have led to a large increase in the number of studies using mice to model specific glaucoma phenotypes. Over the last decade, numerous new mouse models and genetic tools have emerged, providing important insight into the cell biology and genetics of glaucoma. In this review, we describe available mouse genetic models that can be used to study glaucoma-relevant disease/pathobiology. Furthermore, we discuss how these models have been used to gain insights into ocular hypertension (a major risk factor for glaucoma) and glaucomatous retinal ganglion cell death. Finally, the potential for developing new mouse models and using advanced genetic tools and resources for studying glaucoma are discussed. PMID:26116903

Neurocognitive endophenotypes in CGG KI and Fmr1 KO mouse models of Fragile X-Associated disorders: an analysis of the state of the field

PubMed Central

Hunsaker, Michael R.

2013-01-01

It has become increasingly important that the field of behavioral genetics identifies not only the gross behavioral phenotypes associated with a given mutation, but also the behavioral endophenotypes that scale with the dosage of the particular mutation being studied. Over the past few years, studies evaluating the effects of the polymorphic CGG trinucleotide repeat on the FMR1 gene underlying Fragile X-Associated Disorders have reported preliminary evidence for a behavioral endophenotype in human Fragile X Premutation carrier populations as well as the CGG knock-in (KI) mouse model. More recently, the behavioral experiments used to test the CGG KI mouse model have been extended to the Fmr1 knock-out (KO) mouse model. When combined, these data provide compelling evidence for a clear neurocognitive endophenotype in the mouse models of Fragile X-Associated Disorders such that behavioral deficits scale predictably with genetic dosage. Similarly, it appears that the CGG KI mouse effectively models the histopathology in Fragile X-Associated Disorders across CGG repeats well into the full mutation range, resulting in a reliable histopathological endophenotype. These endophenotypes may influence future research directions into treatment strategies for not only Fragile X Syndrome, but also the Fragile X Premutation and Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS). PMID:24627796

Long non-coding RNA expression patterns in lung tissues of chronic cigarette smoke induced COPD mouse model.

PubMed

Zhang, Haiyun; Sun, Dejun; Li, Defu; Zheng, Zeguang; Xu, Jingyi; Liang, Xue; Zhang, Chenting; Wang, Sheng; Wang, Jian; Lu, Wenju

2018-05-15

Long non-coding RNAs (lncRNAs) have critical regulatory roles in protein-coding gene expression. Aberrant expression profiles of lncRNAs have been observed in various human diseases. In this study, we investigated transcriptome profiles in lung tissues of chronic cigarette smoke (CS)-induced COPD mouse model. We found that 109 lncRNAs and 260 mRNAs were significantly differential expressed in lungs of chronic CS-induced COPD mouse model compared with control animals. GO and KEGG analyses indicated that differentially expressed lncRNAs associated protein-coding genes were mainly involved in protein processing of endoplasmic reticulum pathway, and taurine and hypotaurine metabolism pathway. The combination of high throughput data analysis and the results of qRT-PCR validation in lungs of chronic CS-induced COPD mouse model, 16HBE cells with CSE treatment and PBMC from patients with COPD revealed that NR_102714 and its associated protein-coding gene UCHL1 might be involved in the development of COPD both in mouse and human. In conclusion, our study demonstrated that aberrant expression profiles of lncRNAs and mRNAs existed in lungs of chronic CS-induced COPD mouse model. From animal models perspective, these results might provide further clues to investigate biological functions of lncRNAs and their potential target protein-coding genes in the pathogenesis of COPD.

Modeling bladder cancer in mice: opportunities and challenges

PubMed Central

Kobayashi, Takashi; Owczarek, Tomasz B.; McKiernan, James M.; Abate-Shen, Cory

2015-01-01

The prognosis and treatment of bladder cancer have hardly improved in the last 20 years. Bladder cancer remains a debilitating and often fatal disease, and among the most costly cancers to treat. The generation of informative mouse models has the potential to improve our understanding of bladder cancer progression, as well as impact its diagnosis and treatment. However, relatively few mouse models of bladder cancer have been described and particularly few that develop invasive cancer phenotypes. This review focuses on opportunities for improving the landscape of mouse models of bladder cancer. PMID:25533675

Development and function of human innate immune cells in a humanized mouse model.

PubMed

Rongvaux, Anthony; Willinger, Tim; Martinek, Jan; Strowig, Till; Gearty, Sofia V; Teichmann, Lino L; Saito, Yasuyuki; Marches, Florentina; Halene, Stephanie; Palucka, A Karolina; Manz, Markus G; Flavell, Richard A

2014-04-01

Mice repopulated with human hematopoietic cells are a powerful tool for the study of human hematopoiesis and immune function in vivo. However, existing humanized mouse models cannot support development of human innate immune cells, including myeloid cells and natural killer (NK) cells. Here we describe two mouse strains called MITRG and MISTRG, in which human versions of four genes encoding cytokines important for innate immune cell development are knocked into their respective mouse loci. The human cytokines support the development and function of monocytes, macrophages and NK cells derived from human fetal liver or adult CD34(+) progenitor cells injected into the mice. Human macrophages infiltrated a human tumor xenograft in MITRG and MISTRG mice in a manner resembling that observed in tumors obtained from human patients. This humanized mouse model may be used to model the human immune system in scenarios of health and pathology, and may enable evaluation of therapeutic candidates in an in vivo setting relevant to human physiology.

Development and function of human innate immune cells in a humanized mouse model

PubMed Central

Rongvaux, Anthony; Willinger, Tim; Martinek, Jan; Strowig, Till; Gearty, Sofia V.; Teichmann, Lino L.; Saito, Yasuyuki; Marches, Florentina; Halene, Stephanie; Palucka, A. Karolina; Manz, Markus G.; Flavell, Richard A.

2014-01-01

Mice repopulated with human hematopoietic cells are a powerful tool for the study of human hematopoiesis and immune function in vivo. However, existing humanized mouse models are unable to support development of human innate immune cells, including myeloid cells and NK cells. Here we describe a mouse strain, called MI(S)TRG, in which human versions of four genes encoding cytokines important for innate immune cell development are knocked in to their respective mouse loci. The human cytokines support the development and function of monocytes/macrophages and natural killer cells derived from human fetal liver or adult CD34+ progenitor cells injected into the mice. Human macrophages infiltrated a human tumor xenograft in MI(S)TRG mice in a manner resembling that observed in tumors obtained from human patients. This humanized mouse model may be used to model the human immune system in scenarios of health and pathology, and may enable evaluation of therapeutic candidates in an in vivo setting relevant to human physiology. PMID:24633240

Effect of electroacupuncture on brain-derived neurotrophic factor mRNA expression in mouse hippocampus following cerebral ischemia-reperfusion injury.

PubMed

Zhao, Jianxin; Xu, Huazhou; Tian, Yuanxiang; Hu, Manxiang; Xiao, Hongling

2013-04-01

This work aims to observe the effects of electroacupuncture on brain-derived neurotrophic factor (BDNF) mRNA expression in mouse hippocampus following cerebral ischemia-reperfusion injury. The models of mouse cerebral ischemia-reperfusion injury were established. A total of 96 healthy mice were randomly assigned into 4 groups, namely, the sham surgery, model, model + electroacupuncture, and mode + hydergine groups. Mice in the model + electroacupuncture group were treated through electroacupuncture at the Shenshu (BL 23), Geshu (BL 17), and Baihui (GV 20) acupoints. Mice in the model+hydergine group were intragastrically administered with hydergine (0.77 mg/kg(-1) x day(-1)). The levels of BDNF mRNA expressions in the hippocampus were ana lyzed through a semi-quantitative reverse transcription-polymerase chain reaction assay on days 1 and 7 after the surgeries. BDNF mRNA expressions in the mouse hippocampus of the model group on days 1 and 7 after the surgery were higher than those of the sham surgery group (both P < 0.01). On days 1 and 7 of the electroacupuncture treatment, BDNF mRNA expression in the mouse hippocampus of the model + electroacupuncture group was significantly elevated compared with the model group (both P < 0.01) or the model + hydergine group (both P < 0.01). On days 1 and 7 of the hydergine treatment, BDNF mRNA expression in the mouse hippocampus of the model + hydergine group tended to increase compared with the model group; however, statistical significance was not achieved (both P > 0.05). Electroacupuncture treatment enhances endogenous BDNF expression, which may improve the survival environment for intracerebral neurons and inhibit the apoptosis of hippocampal cells.

Intramyocardial Injection of siRNAs Can Efficiently Establish Myocardial Tissue-Specific Renalase Knockdown Mouse Model.

PubMed

Huang, Kun; Liu, Ju; Zhang, Hui; Wang, Jiliang; Li, Huili

2016-01-01

Ischaemia/reperfusion (I/R) injury will cause additional death of cardiomyocytes in ischaemic heart disease. Recent studies revealed that renalase was involved in the I/R injury. So, the myocardial tissue-specific knockdown mouse models were needed for the investigations of renalase. To establish the mouse models, intramyocardial injection of siRNAs targeting renalase was performed in mice. The wild distribution and high transfection efficiency of the siRNAs were approved. And the renalase expression was efficiently suppressed in myocardial tissue. Compared with the high cost, time consumption, and genetic compensation risk of the Cre/loxP technology, RNA interference (RNAi) technology is much cheaper and less time-consuming. Among the RNAi technologies, injection of siRNAs is safer than virus. And considering the properties of the I/R injury mouse models, the efficiency and durability of injection with siRNAs are acceptable for the studies. Altogether, intramyocardial injection of siRNAs targeting renalase is an economical, safe, and efficient method to establish myocardial tissue-specific renalase knockdown mouse models.

Improvements and Limitations of Humanized Mouse Models for HIV Research: NIH/NIAID "Meet the Experts" 2015 Workshop Summary.

PubMed

Akkina, Ramesh; Allam, Atef; Balazs, Alejandro B; Blankson, Joel N; Burnett, John C; Casares, Sofia; Garcia, J Victor; Hasenkrug, Kim J; Kashanchi, Fatah; Kitchen, Scott G; Klein, Florian; Kumar, Priti; Luster, Andrew D; Poluektova, Larisa Y; Rao, Mangala; Sanders-Beer, Brigitte E; Shultz, Leonard D; Zack, Jerome A

2016-02-01

The number of humanized mouse models for the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and other infectious diseases has expanded rapidly over the past 8 years. Highly immunodeficient mouse strains, such as NOD/SCID/gamma chain(null) (NSG, NOG), support better human hematopoietic cell engraftment. Another improvement is the derivation of highly immunodeficient mice, transgenic with human leukocyte antigens (HLAs) and cytokines that supported development of HLA-restricted human T cells and heightened human myeloid cell engraftment. Humanized mice are also used to study the HIV reservoir using new imaging techniques. Despite these advances, there are still limitations in HIV immune responses and deficits in lymphoid structures in these models in addition to xenogeneic graft-versus-host responses. To understand and disseminate the improvements and limitations of humanized mouse models to the scientific community, the NIH sponsored and convened a meeting on April 15, 2015 to discuss the state of knowledge concerning these questions and best practices for selecting a humanized mouse model for a particular scientific investigation. This report summarizes the findings of the NIH meeting.

Oral recombinant human or mouse lactoferrin reduces Mycobacterium tuberculosis TDM induced granulomatous lung pathology.

PubMed

Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

2017-02-01

Trehalose 6'6-dimycolate (TDM) is the most abundant glycolipid on the cell wall of Mycobacterium tuberculosis (MTB). TDM is capable of inducing granulomatous pathology in mouse models that resembles those induced by MTB infection. Using the acute TDM model, this work investigates the effect of recombinant human and mouse lactoferrin to reduce granulomatous pathology. C57BL/6 mice were injected intravenously with TDM at a dose of 25 μg·mouse -1 . At day 4 and 6, recombinant human or mouse lactoferrin (1 mg·(100 μL) -1 ·mouse -1 ) were delivered by gavage. At day 7 after TDM injection, mice were evaluated for lung pathology, cytokine production, and leukocyte populations. Mice given human or mouse lactoferrin had reduced production of IL-12p40 in their lungs. Mouse lactoferrin increased IL-6 and KC (CXCL1) in lung tissue. Increased numbers of macrophages were observed in TDM-injected mice given human or mouse lactoferrin. Granulomatous pathology, composed of mainly migrated leukocytes, was visually reduced in mice that received human or mouse lactoferrin. Quantitation of granulomatous pathology demonstrated a significant decrease in mice given human or mouse lactoferrin compared with TDM control mice. This report is the first to directly compare the immune modulatory effects of both heterologous recombinant human and homologous mouse lactoferrin on the development of TDM-induced granulomas.

A Sodium Channel Myotonia Presenting with Intermittent Dysphagia as a Manifestation of a Rare SCN4A Variant.

PubMed

Benhammou, Jihane N; Phan, Jennifer; Lee, Hane; Ghassemi, Kevin; Parsons, William; Grody, Wayne W; Pisegna, Joseph R

2017-03-01

The voltage gated sodium channel SCN4A mutations account for non-dystrophic myotonia and include a heterogeneous group of conditions that include hyperkalemic periodic paralysis, paramyotonica congenita, potassium-aggravated myotonia, and hypokalemic periodic paralysis type 2. This case report proposes that a rare variant p.Pro1629Leu in SCN4A can cause a skeletal muscle deficit with intermittent dysphagia.

A Sodium Channel Myotonia Presenting with Intermittent Dysphagia as a Manifestation of a Rare SCN4A Variant

PubMed Central

Benhammou, Jihane N.; Phan, Jennifer; Lee, Hane; Ghassemi, Kevin; Parsons, William; Grody, Wayne W.; Pisegna, Joseph R.

2016-01-01

The voltage gated sodium channel SCN4A mutations account for non-dystrophic myotonia and include a heterogenous group of conditions that include hyperkalemic periodic paralysis, paramyotonica congenita, potassium-aggravated myotonia and hypokalemic periodic paralysis type 2. This case report proposes that a rare variant p.Pro1629Leu in SCN4A can cause skeletal muscle deficit with intermittent dysphagia. PMID:28012096

The Mechanosensory Ca2+ Channel as a Central Regulator of Prostate Tumor Cell Migration and Invasiveness

DTIC Science & Technology

2008-01-01

contribute to major human diseases, including muscular dystrophy, kidney disease, cardiac arrhythmias, hyper- tension, and tumor cell invasion...explain why the absence of dystrophin in Duchenne muscular dystrophic muscle results in TRPC1 channels being abnormally gated open (Section VIII.A.3... Muscular Dystrophy BothTRPC1andMscCa are expressed in skeletalmuscle and bothhave been implicated in the muscular degeneration that occurs in Duchenne

Mouse neuroblastoma cell-based model and the effect of epileptic events on calcium oscillations and neural spikes

NASA Astrophysics Data System (ADS)

Kim, Suhwan; Jung, Unsang; Baek, Juyoung; Lee, Sangwon; Jung, Woonggyu; Kim, Jeehyun; Kang, Shinwon

2013-01-01

Recently, mouse neuroblastoma cells have been considered as an attractive model for the study of human neurological and prion diseases, and they have been intensively used as a model system in different areas. For example, the differentiation of neuro2a (N2A) cells, receptor-mediated ion current, and glutamate-induced physiological responses have been actively investigated with these cells. These mouse neuroblastoma N2A cells are of interest because they grow faster than other cells of neural origin and have a number of other advantages. The calcium oscillations and neural spikes of mouse neuroblastoma N2A cells in epileptic conditions are evaluated. Based on our observations of neural spikes in these cells with our proposed imaging modality, we reported that they can be an important model in epileptic activity studies. We concluded that mouse neuroblastoma N2A cells produce epileptic spikes in vitro in the same way as those produced by neurons or astrocytes. This evidence suggests that increased levels of neurotransmitter release due to the enhancement of free calcium from 4-aminopyridine causes the mouse neuroblastoma N2A cells to produce epileptic spikes and calcium oscillations.

High-fertility phenotypes: two outbred mouse models exhibit substantially different molecular and physiological strategies warranting improved fertility.

PubMed

Langhammer, Martina; Michaelis, Marten; Hoeflich, Andreas; Sobczak, Alexander; Schoen, Jennifer; Weitzel, Joachim M

2014-01-01

Animal models are valuable tools in fertility research. Worldwide, there are more than 400 transgenic or knockout mouse models available showing a reproductive phenotype; almost all of them exhibit an infertile or at least subfertile phenotype. By contrast, animal models revealing an improved fertility phenotype are barely described. This article summarizes data on two outbred mouse models exhibiting a 'high-fertility' phenotype. These mouse lines were generated via selection over a time period of more than 40 years and 161 generations. During this selection period, the number of offspring per litter and the total birth weight of the entire litter nearly doubled. Concomitantly with the increased fertility phenotype, several endocrine parameters (e.g. serum testosterone concentrations in male animals), physiological parameters (e.g. body weight, accelerated puberty, and life expectancy), and behavioral parameters (e.g. behavior in an open field and endurance fitness on a treadmill) were altered. We demonstrate that the two independently bred high-fertility mouse lines warranted their improved fertility phenotype using different molecular and physiological strategies. The fertility lines display female- as well as male-specific characteristics. These genetically heterogeneous mouse models provide new insights into molecular and cellular mechanisms that enhance fertility. In view of decreasing fertility in men, these models will therefore be a precious information source for human reproductive medicine. Translated abstract A German translation of abstract is freely available at http://www.reproduction-online.org/content/147/4/427/suppl/DC1.

Ultrasonic vocalizations: a tool for behavioural phenotyping of mouse models of neurodevelopmental disorders

PubMed Central

Scattoni, Maria Luisa; Crawley, Jacqueline; Ricceri, Laura

2009-01-01

In neonatal mice ultrasonic vocalizations have been studied both as an early communicative behavior of the pup-mother dyad and as a sign of an aversive affective state. Adult mice of both sexes produce complex ultrasonic vocalization patterns in different experimental/social contexts. All these vocalizations are becoming an increasingly valuable assay for behavioral phenotyping throughout the mouse life-span and alterations of the ultrasound patterns have been reported in several mouse models of neurodevelopmental disorders. Here we also show that the modulation of vocalizations by maternal cues (maternal potentiation paradigm) – originally identified and investigated in rats - can be measured in C57Bl/6 mouse pups with appropriate modifications of the rat protocol and can likely be applied to mouse behavioral phenotyping. In addition we suggest that a detailed qualitative evaluation of neonatal calls together with analysis of adult mouse vocalization patterns in both sexes in social settings, may lead to a greater understanding of the communication value of vocalizations in mice. Importantly, both neonatal and adult USV altered patterns can be determined during the behavioural phenotyping of mouse models of human neurodevelopmental and neuropsychiatric disorders, starting from those in which deficits in communication are a primary symptom. PMID:18771687

A Comparison of Some Organizational Characteristics of the Mouse Central Retina and the Human Macula

PubMed Central

Hoo, Juyea; Yee, Claudine; Williams, David S.

2015-01-01

Mouse models have greatly assisted our understanding of retinal degenerations. However, the mouse retina does not have a macula, leading to the question of whether the mouse is a relevant model for macular degeneration. In the present study, a quantitative comparison between the organization of the central mouse retina and the human macula was made, focusing on some structural characteristics that have been suggested to be important in predisposing the macula to stresses leading to degeneration: photoreceptor density, phagocytic load on the RPE, and the relative thinness of Bruch’s membrane. Light and electron microscopy measurements from retinas of two strains of mice, together with published data on human retinas, were used for calculations and subsequent comparisons. As in the human retina, the central region of the mouse retina possesses a higher photoreceptor cell density and a thinner Bruch’s membrane than in the periphery; however, the magnitudes of these periphery to center gradients are larger in the human. Of potentially greater relevance is the actual photoreceptor cell density, which is much greater in the mouse central retina than in the human macula, underlying a higher phagocytic load for the mouse RPE. Moreover, at eccentricities that correspond to the peripheral half of the human macula, the rod to cone ratio is similar between mouse and human. Hence, with respect to photoreceptor density and phagocytic load of the RPE, the central mouse retina models at least the more peripheral part of the macula, where macular degeneration is often first evident. PMID:25923208

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Ying; Adachi, Hiroaki, E-mail: hadachi-ns@umin.org; Department of Neurology, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu 807-8555

Spinal and bulbar muscular atrophy (SBMA) is an inherited motor neuron disease caused by the expansion of a polyglutamine (polyQ)-encoding tract within the androgen receptor (AR) gene. The pathologic features of SBMA are motor neuron loss in the spinal cord and brainstem and diffuse nuclear accumulation and nuclear inclusions of mutant AR in residual motor neurons and certain visceral organs. Hepatocyte growth factor (HGF) is a polypeptide growth factor which has neuroprotective properties. To investigate whether HGF overexpression can affect disease progression in a mouse model of SBMA, we crossed SBMA transgenic model mice expressing an AR gene with anmore » expanded CAG repeat with mice overexpressing HGF. Here, we report that high expression of HGF induces Akt phosphorylation and modestly ameliorated motor symptoms in an SBMA transgenic mouse model treated with or without castration. These findings suggest that HGF overexpression can provide a potential therapeutic avenue as a combination therapy with disease-modifying therapies in SBMA. - Highlights: • HGF overexpression ameliorates the motor phenotypes of the SBMA mouse model. • HGF overexpression induces Akt phosphorylation in the SBMA mouse model. • This is the first report of combination therapy in a mouse model of polyQ diseases.« less

Defining the optimal animal model for translational research using gene set enrichment analysis.

PubMed

Weidner, Christopher; Steinfath, Matthias; Opitz, Elisa; Oelgeschläger, Michael; Schönfelder, Gilbert

2016-08-01

The mouse is the main model organism used to study the functions of human genes because most biological processes in the mouse are highly conserved in humans. Recent reports that compared identical transcriptomic datasets of human inflammatory diseases with datasets from mouse models using traditional gene-to-gene comparison techniques resulted in contradictory conclusions regarding the relevance of animal models for translational research. To reduce susceptibility to biased interpretation, all genes of interest for the biological question under investigation should be considered. Thus, standardized approaches for systematic data analysis are needed. We analyzed the same datasets using gene set enrichment analysis focusing on pathways assigned to inflammatory processes in either humans or mice. The analyses revealed a moderate overlap between all human and mouse datasets, with average positive and negative predictive values of 48 and 57% significant correlations. Subgroups of the septic mouse models (i.e., Staphylococcus aureus injection) correlated very well with most human studies. These findings support the applicability of targeted strategies to identify the optimal animal model and protocol to improve the success of translational research. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

Transgenic and gene knockout mice in gastric cancer research

PubMed Central

Jiang, Yannan; Yu, Yingyan

2017-01-01

Mouse models are useful tool for carcinogenic study. They will greatly enrich the understanding of pathogenesis and molecular mechanisms for gastric cancer. However, only few of mice could develop gastric cancer spontaneously. With the development and improvement of gene transfer technology, investigators created a variety of transgenic and knockout/knockin mouse models of gastric cancer, such as INS-GAS mice and gastrin knockout mice. Combined with helicobacter infection and carcinogens treatment, these transgenic/knockout/knockin mice developed precancerous or cancerous lesions, which are proper for gene function study or experimental therapy. Here we review the progression of genetically engineered mouse models on gastric cancer research, and emphasize the effects of chemical carcinogens or infectious factors on carcinogenesis of genetically modified mouse. We also emphasize the histological examination on mouse stomach. We expect to provide researchers with some inspirations on this field. PMID:27713138

A Mouse Model to Investigate Postmenopausal Biology as an Etiology of Ovarian Cancer Risk

DTIC Science & Technology

2006-11-01

Wv mice and genetic alterations such as p53, pten, or p27kip1, which are found in human ovarian cancer. 2. Body: Research Progress In the first year...press (Yang et al., Am. J. Pathology 2007). To collaborate with the mouse model study, we have also examined human ovaries obtained from prophylactic...results in the coming years. Xu, Xiangxi, Ph.D. 8 3. Key Research Accomplishments (1) Further verify the relevance of the Wv mouse model to human

The Oncogenic Role of RhoGAPs in Basal-Like Breast Cancer

DTIC Science & Technology

2015-02-01

cell lines, and mouse models . c) In vivo tumorigenesis and metastasis assays. Milestones: Identify whether ArhGAP11A and RacGAP1 can promote tumor growth...also upregulated in basal (C3(I)-Tag) but not luminal (MMTV-Neu) genetically- engineered mouse models (Fig. 1B). At the protein level, RacGAP1 was...hypothesis that these RhoGAPs are indeed playing an oncogenic role in these cells. Human Tumors Mouse Model Tumors Normal Luminal A Basal-like Normal

A Physiologically Based Kinetic Model of Rat and Mouse Gestation: Disposition of a Weak Acid

EPA Science Inventory

A physiologically based toxicokinetic model of gestation in the rat mouse has been developed. The model is superimposed on the normal growth curve for nonpregnant females. It describes the entire gestation period including organogenesis. The model consists of uterus, mammary tiss...

Priceless GEMMs: genetically engineered mouse models for colorectal cancer drug development.

PubMed

Roper, Jatin; Hung, Kenneth E

2012-08-01

To establish effective drug development for colorectal cancer (CRC), preclinical models that are robust surrogates for human disease are crucial. Mouse models are an attractive platform because of their relatively low cost, short life span, and ease of use. There are two main categories of mouse CRC models: xenografts derived from implantation of CRC cells or tumors in immunodeficient mice; and genetically engineered mouse models (GEMMs) derived from modification of human cancer predisposition genes, resulting in spontaneous tumor formation. Here, we review xenografts and GEMMs and focus on their potential application in translational research. Furthermore, we describe newer GEMMs for sporadic CRC that are particularly suitable for drug testing. Finally, we discuss recent advances in small-animal imaging, such as optical colonoscopy, which allow in vivo assessment of tumors. With the increasing sophistication of GEMMs, our preclinical armamentarium provides new hope for the ongoing war against CRC. Copyright © 2012. Published by Elsevier Ltd.

A Genetically Engineered Mouse Model of Sporadic Colorectal Cancer.

PubMed

Betzler, Alexander M; Kochall, Susan; Blickensdörfer, Linda; Garcia, Sebastian A; Thepkaysone, May-Linn; Nanduri, Lahiri K; Muders, Michael H; Weitz, Jürgen; Reissfelder, Christoph; Schölch, Sebastian

2017-07-06

Despite the advantages of easy applicability and cost-effectiveness, colorectal cancer mouse models based on tumor cell injection have severe limitations and do not accurately simulate tumor biology and tumor cell dissemination. Genetically engineered mouse models have been introduced to overcome these limitations; however, such models are technically demanding, especially in large organs such as the colon in which only a single tumor is desired. As a result, an immunocompetent, genetically engineered mouse model of colorectal cancer was developed which develops highly uniform tumors and can be used for tumor biology studies as well as therapeutic trials. Tumor development is initiated by surgical, segmental infection of the distal colon with adeno-cre virus in compound conditionally mutant mice. The tumors can be easily detected and monitored via colonoscopy. We here describe the surgical technique of segmental adeno-cre infection of the colon, the surveillance of the tumor via high-resolution colonoscopy and present the resulting colorectal tumors.

Absence of Prenatal Forebrain Defects in the Dp(16)1Yey/+ Mouse Model of Down Syndrome

PubMed Central

Goodliffe, Joseph W.; Olmos-Serrano, Jose Luis; Aziz, Nadine M.; Pennings, Jeroen L.A.; Guedj, Faycal; Bianchi, Diana W.

2016-01-01

Studies in humans with Down syndrome (DS) show that alterations in fetal brain development are followed by postnatal deficits in neuronal numbers, synaptic plasticity, and cognitive and motor function. This same progression is replicated in several mouse models of DS. Dp(16)1Yey/+ (hereafter called Dp16) is a recently developed mouse model of DS in which the entire region of mouse chromosome 16 that is homologous to human chromosome 21 has been triplicated. As such, Dp16 mice may more closely reproduce neurodevelopmental changes occurring in humans with DS. Here, we present the first comprehensive cellular and behavioral study of the Dp16 forebrain from embryonic to adult stages. Unexpectedly, our results demonstrate that Dp16 mice do not have prenatal brain defects previously reported in human fetal neocortex and in the developing forebrains of other mouse models, including microcephaly, reduced neurogenesis, and abnormal cell proliferation. Nevertheless, we found impairments in postnatal developmental milestones, fewer inhibitory forebrain neurons, and deficits in motor and cognitive performance in Dp16 mice. Therefore, although this new model does not express prenatal morphological phenotypes associated with DS, abnormalities in the postnatal period appear sufficient to produce significant cognitive deficits in Dp16. SIGNIFICANCE STATEMENT Down syndrome (DS) leads to intellectual disability. Several mouse models have increased our understanding of the neuropathology of DS and are currently being used to test therapeutic strategies. A new mouse model that contains an expanded number of DS-related genes, known as Dp(16)1Yey/+ (Dp16), has been generated recently. We sought to determine whether the extended triplication creates a better phenocopy of DS-related brain pathologies. We measured embryonic development, forebrain maturation, and perinatal/adult behavior and revealed an absence of prenatal phenotypes in Dp16 fetal brain, but specific cellular and behavioral deficits after the first 2 postnatal weeks. These results uncover important differences in prenatal phenotype between Dp16 animals and humans with DS and other DS mouse models. PMID:26961948

Use of a highly sensitive strand-specific quantitative PCR to identify abortive replication in the mouse model of respiratory syncytial virus disease

PubMed Central

2010-01-01

Background The BALB/c mouse is commonly used to study RSV infection and disease. However, despite the many advantages of this well-characterised model, the inoculum is large, viral replication is restricted and only a very small amount of virus can be recovered from infected animals. A key question in this model is the fate of the administered virus. Is replication really being measured or is the model measuring the survival of the virus over time? To answer these questions we developed a highly sensitive strand-specific quantitative PCR (QPCR) able to accurately quantify the amount of RSV replication in the BALB/c mouse lung, allowing characterisation of RSV negative and positive strand RNA dynamics. Results In the mouse lung, no increase in RSV genome was seen above the background of the original inoculum whilst only a limited transient increase (< 1 log) in positive strand, replicative intermediate (RI) RNA occurred. This RNA did however persist at detectable levels for 59 days post infection. As expected, ribavirin therapy reduced levels of infectious virus and RI RNA in the mouse lung. However, whilst Palivizumab therapy was also able to reduce levels of infectious virus, it failed to prevent production of intracellular RI RNA. A comparison of RSV RNA kinetics in human (A549) and mouse (KLN205) cell lines demonstrated that RSV replication was also severely delayed and impaired in vitro in the mouse cells. Conclusions This is the first time that such a sensitive strand-specific QPCR technique has been to the RSV mouse system. We have accurately quantified the restricted and abortive nature of RSV replication in the mouse. Further in vitro studies in human and mouse cells suggest this restricted replication is due at least in part to species-specific host cell-viral interactions. PMID:20860795

Establishment of mouse neuron and microglial cell co-cultured models and its action mechanism.

PubMed

Zhang, Bo; Yang, Yunfeng; Tang, Jun; Tao, Yihao; Jiang, Bing; Chen, Zhi; Feng, Hua; Yang, Liming; Zhu, Gang

2017-06-27

The objective of this study is to establish a co-culture model of mouse neurons and microglial cells, and to analyze the mechanism of action of oxygen glucose deprivation (OGD) and transient oxygen glucose deprivation (tOGD) preconditioning cell models. Mouse primary neurons and BV2 microglial cells were successfully cultured, and the OGD and tOGD models were also established. In the co-culture of mouse primary neurons and microglial cells, the cell number of tOGD mouse neurons and microglial cells was larger than the OGD cell number, observed by a microscope. CCK-8 assay result showed that at 1h after treatment, the OD value in the control group is lower compared to all the other three groups (P < 0.05). The treatment group exhibited the highest OD value among the four groups. The results observed at 5h were consistent with the results at 1 h. Flow cytometry results showed that at 1h after treatment the apoptosis percentages is higher in the control group compared to other three groups (P < 0.05). Mouse brain tissues were collected and primary neurons cells were cultured. In the meantime mouse BV2 microglia cells were cultured. Two types of cells were co-cultured, and OGD and tOGD cell models were established. There were four groups in the experiment: control group (OGD), treatment group (tOGD+OGD), placebo group (tOGD+OGD+saline) and minocycline intervention group (tOGD+OGD+minocycline). CCK-8 kit was used to detect cell viability and flow cytometry was used to detect apoptosis. In this study, mouse primary neurons and microglial cells were co-cultured. The OGD and tOGD models were established successfully. tOGD was able to effectively protect neurons and microglial cells from damage, and inhibit the apoptosis caused by oxygen glucose deprivation.

Actinic keratosis modelling in mice: A translational study

PubMed Central

Vandenberghe, Isabelle; Cartron, Valérie; Cèbe, Patrick; Blanchet, Jean-Christophe; Sibaud, Vincent; Guilbaud, Nicolas; Audoly, Laurent; Lamant, Laurence; Kruczynski, Anna

2017-01-01

Background Actinic keratoses (AK) are pre-malignant cutaneous lesions caused by prolonged exposure to ultraviolet radiation. As AKs lesions are generally accepted to be the initial lesions in a disease continuum that progresses to squamous cell carcinoma (SCC), AK lesions have to be treated. They are also the second most common reason for visits to the dermatologist. Several treatments are available but their efficacy still needs to be improved. The UV-B-induced KA lesion mouse model is used in preclinical studies to assess the efficacy of novel molecules, even though it is often more representative of advanced AK or SCC. Objectives Here we report on a translational study, comparing the various stages of AK development in humans and in the UV-B irradiated mouse model, as well as the optimization of photograph acquisition of AK lesions on mouse skin. Methods Human and mouse skin lesions were analysed by histology and immunohistochemistry. Mouse lesions were also assessed using a digital dermatoscope. Results An histological and phenotypic analysis, including p53, Ki67 and CD3 expression detection, performed on human and mouse AK lesions, shows that overall AK modelling in mice is relevant in the clinical situation. Some differences are observed, such as disorganization of keratinocytes of the basal layer and a number of atypical nuclei which are more numerous in human AK, whereas much more pronounced acanthosis is observed in skin lesion in mice. Thanks to this translational study, we are able to select appropriate experimental conditions for establishing either early or advanced stage AK or an SCC model. Furthermore, we optimized photograph acquisition of AK lesions on mouse skin by using a digital dermatoscope which is also used in clinics and allows reproducible photograph acquisition for further reliable assessment of mouse lesions. Use of this camera is illustrated through a pharmacological study assessing the activity of CARAC®. Conclusion These data demonstrate that this mouse model of UV-B-induced skin lesions is predictive for the identification of novel therapeutic treatments for both early and advanced stages of the disease. PMID:28662116

Taltirelin alleviates fatigue-like behavior in mouse models of cancer-related fatigue.

PubMed

Dougherty, John P; Wolff, Brian S; Cullen, Mary J; Saligan, Leorey N; Gershengorn, Marvin C

2017-10-01

Fatigue affects most cancer patients and has numerous potential causes, including cancer itself and cancer treatment. Cancer-related fatigue (CRF) is not relieved by rest, can decrease quality of life, and has no FDA-approved therapy. Thyrotropin-releasing hormone (TRH) has been proposed as a potential novel treatment for CRF, but its efficacy against CRF remains largely untested. Thus, we tested the TRH analog, taltirelin (TAL), in mouse models of CRF. To model fatigue, we used a mouse model of chemotherapy, a mouse model of radiation therapy, and mice bearing colon 26 carcinoma tumors. We used the treadmill fatigue test to assess fatigue-like behavior after treatment with TAL. Additionally, we used wild-type and TRH receptor knockout mice to determine which TRH receptor was necessary for the actions of TAL. Tumor-bearing mice displayed muscle wasting and all models caused fatigue-like behavior, with mice running a shorter distance in the treadmill fatigue test than controls. TAL reversed fatigue-like behavior in all three models and the mouse TRH 1 receptor was necessary for the effects of TAL. These data suggest that TAL may be useful in alleviating fatigue in all cancer patients and provide further support for evaluating TAL as a potential therapy for CRF in humans. Published by Elsevier Ltd.

MR images of mouse brain using clinical 3T MR scanner and 4CH-Mouse coil

NASA Astrophysics Data System (ADS)

Lim, Soo Mee; Park, Eun Mi; Lyoo, In Kyoon; Lee, Junghyun; Han, Bo Mi; Lee, Jeong Kyong; Lee, Su Bin

2015-07-01

Objectives: Although small-bore high-field magnets are useful for research in small rodent models,this technology, however, has not been easily accessible to most researchers. This current study, thus,tried to evaluate the usability of 4CH-Mouse coil (Philips Healthcare, Best, the Netherlands) forpreclinical investigations in clinical 3T MR scan environment. We evaluated the effects of ischemicpreconditioning (IP) in the mouse stroke model with clinical 3T MR scanner and 4CH-Mouse coil. Materials and Methods: Experiments were performed on male C57BL/6 mice that either received the IP or sham operation (control). Three different MR sequences including diffusion weighted images (DWI), T2-weighted images (T2WI), and fluid attenuated inversion recovery (FLAIR) were performed on the mouse brains following 24, 72 hours of middle cerebral artery occlusion (MCAO) and analyzed for infarct lesions. Results: The images showed that the IP-treated mouse brains had significantly smaller infarct volumes compared to the control group. Of the MR sequences employed, the T2WI showed the highest level of correlations with postmortem infarct volume measurements. Conclusions: The clinical 3T MR scanner turned out to have a solid potential as a practical tool for imaging small animal brains. MR sequences including DWI, T2WI, FLAIR were obtained with acceptable resolution and in a reasonable time constraint in evaluating a mouse stroke model brain.

Increased sphingosine-1-phosphate improves muscle regeneration in acutely injured mdx mice

PubMed Central

2013-01-01

Background Presently, there is no effective treatment for the lethal muscle wasting disease Duchenne muscular dystrophy (DMD). Here we show that increased sphingosine-1-phoshate (S1P) through direct injection or via the administration of the small molecule 2-acetyl-4(5)-tetrahydroxybutyl imidazole (THI), an S1P lyase inhibitor, has beneficial effects in acutely injured dystrophic muscles of mdx mice. Methods We treated mdx mice with and without acute injury and characterized the histopathological and functional effects of increasing S1P levels. We also tested exogenous and direct administration of S1P on mdx muscles to examine the molecular pathways under which S1P promotes regeneration in dystrophic muscles. Results Short-term treatment with THI significantly increased muscle fiber size and extensor digitorum longus (EDL) muscle specific force in acutely injured mdx limb muscles. In addition, the accumulation of fibrosis and fat deposition, hallmarks of DMD pathology and impaired muscle regeneration, were lower in the injured muscles of THI-treated mdx mice. Furthermore, increased muscle force was observed in uninjured EDL muscles with a longer-term treatment of THI. Such regenerative effects were linked to the response of myogenic cells, since intramuscular injection of S1P increased the number of Myf5nlacz/+ positive myogenic cells and newly regenerated myofibers in injured mdx muscles. Intramuscular injection of biotinylated-S1P localized to muscle fibers, including newly regenerated fibers, which also stained positive for S1P receptor 1 (S1PR1). Importantly, plasma membrane and perinuclear localization of phosphorylated S1PR1 was observed in regenerating muscle fibers of mdx muscles. Intramuscular increases of S1P levels, S1PR1 and phosphorylated ribosomal protein S6 (P-rpS6), and elevated EDL muscle specific force, suggest S1P promoted the upregulation of anabolic pathways that mediate skeletal muscle mass and function. Conclusions These data show that S1P is beneficial for muscle regeneration and functional gain in dystrophic mice, and that THI, or other pharmacological agents that raise S1P levels systemically, may be developed into an effective treatment for improving muscle function and reducing the pathology of DMD. PMID:23915702

Non-dystrophic myotonia: prospective study of objective and patient reported outcomes.

PubMed

Trivedi, Jaya R; Bundy, Brian; Statland, Jeffrey; Salajegheh, Mohammad; Rayan, Dipa Raja; Venance, Shannon L; Wang, Yunxia; Fialho, Doreen; Matthews, Emma; Cleland, James; Gorham, Nina; Herbelin, Laura; Cannon, Stephen; Amato, Anthony; Griggs, Robert C; Hanna, Michael G; Barohn, Richard J

2013-07-01

Non-dystrophic myotonias are rare diseases caused by mutations in skeletal muscle chloride and sodium ion channels with considerable phenotypic overlap between diseases. Few prospective studies have evaluated the sensitivity of symptoms and signs of myotonia in a large cohort of patients. We performed a prospective observational study of 95 participants with definite or clinically suspected non-dystrophic myotonia recruited from six sites in the USA, UK and Canada between March 2006 and March 2009. We used the common infrastructure and data elements provided by the NIH-funded Rare Disease Clinical Research Network. Outcomes included a standardized symptom interview and physical exam; the Short Form-36 and the Individualized Neuromuscular Quality of Life instruments; electrophysiological short and prolonged exercise tests; manual muscle testing; and a modified get-up-and-go test. Thirty-two participants had chloride channel mutations, 34 had sodium channel mutations, nine had myotonic dystrophy type 2, one had myotonic dystrophy type 1, and 17 had no identified mutation. Phenotype comparisons were restricted to those with sodium channel mutations, chloride channel mutations, and myotonic dystrophy type 2. Muscle stiffness was the most prominent symptom overall, seen in 66.7% to 100% of participants. In comparison with chloride channel mutations, participants with sodium mutations had an earlier age of onset of stiffness (5 years versus 10 years), frequent eye closure myotonia (73.5% versus 25%), more impairment on the Individualized Neuromuscular Quality of Life summary score (20.0 versus 9.44), and paradoxical eye closure myotonia (50% versus 0%). Handgrip myotonia was seen in three-quarters of participants, with warm up of myotonia in 75% chloride channel mutations, but also 35.3% of sodium channel mutations. The short exercise test showed ≥10% decrement in the compound muscle action potential amplitude in 59.3% of chloride channel participants compared with 27.6% of sodium channel participants, which increased post-cooling to 57.6% in sodium channel mutations. In evaluation of patients with clinical and electrical myotonia, despite considerable phenotypic overlap, the presence of eye closure myotonia, paradoxical myotonia, and an increase in short exercise test sensitivity post-cooling suggest sodium channel mutations. Outcomes designed to measure stiffness or the electrophysiological correlates of stiffness may prove useful for future clinical trials, regardless of underlying mutation, and include patient-reported stiffness, bedside manoeuvres to evaluate myotonia, muscle specific quality of life instruments and short exercise testing.

Pedicle screw versus hybrid posterior instrumentation for dystrophic neurofibromatosis scoliosis.

PubMed

Wang, Jr-Yi; Lai, Po-Liang; Chen, Wen-Jer; Niu, Chi-Chien; Tsai, Tsung-Ting; Chen, Lih-Huei

2017-06-01

Surgical management of severe rigid dystrophic neurofibromatosis (NF) scoliosis is technically demanding and produces varying results. In the current study, we reviewed 9 patients who were treated with combined anterior and posterior fusion using different types of instrumentation (i.e., pedicle screw, hybrid, and all-hook constructs) at our institute.Between September 2001 and July 2010 at our institute, 9 patients received anterior release/fusion and posterior fusion with different types of instrumentation, including a pedicle screw construct (n = 5), a hybrid construct (n = 3), and an all-hook construct (n = 1). We compared the pedicle screw group with the hybrid group to analyze differences in preoperative curve angle, immediate postoperative curve reduction, and latest follow-up curve angle.The mean follow-up period was 9.5 ± 2.9 years. The average age at surgery was 10.3 ± 3.9 years. The average preoperative scoliosis curve was 61.3 ± 13.8°, and the average preoperative kyphosis curve was 39.8 ± 19.7°. The average postoperative scoliosis and kyphosis curves were 29.7 ± 10.7° and 21.0 ± 13.5°, respectively. The most recent follow-up scoliosis and kyphosis curves were 43.4 ± 17.3° and 29.4 ± 18.9°, respectively. There was no significant difference in the correction angle (either coronal or sagittal), and there was no significant difference in the loss of sagittal correction between the pedicle screw construct group and the hybrid construct group. However, the patients who received pedicle screw constructs had significantly less loss of coronal correction (P < .05). Two patients with posterior instrumentation, one with an all-hook construct and the other with a hybrid construct, required surgical revision because of progression of deformity.It is difficult to intraoperatively correct dystrophic deformity and to maintain this correction after surgery. Combined anterior release/fusion and posterior fusion using either a pedicle screw construct or a hybrid construct provide similar curve corrections both sagittally and coronally. After long-term follow-up, sagittal correction was maintained with both constructs. However, patients treated with posterior instrumentation using pedicle screw constructs had significantly less loss of coronal correction.

Pedicle screw versus hybrid posterior instrumentation for dystrophic neurofibromatosis scoliosis

PubMed Central

Wang, Jr-Yi; Lai, Po-Liang; Chen, Wen-Jer; Niu, Chi-Chien; Tsai, Tsung-Ting; Chen, Lih-Huei

2017-01-01

Abstract Surgical management of severe rigid dystrophic neurofibromatosis (NF) scoliosis is technically demanding and produces varying results. In the current study, we reviewed 9 patients who were treated with combined anterior and posterior fusion using different types of instrumentation (i.e., pedicle screw, hybrid, and all-hook constructs) at our institute. Between September 2001 and July 2010 at our institute, 9 patients received anterior release/fusion and posterior fusion with different types of instrumentation, including a pedicle screw construct (n = 5), a hybrid construct (n = 3), and an all-hook construct (n = 1). We compared the pedicle screw group with the hybrid group to analyze differences in preoperative curve angle, immediate postoperative curve reduction, and latest follow-up curve angle. The mean follow-up period was 9.5 ± 2.9 years. The average age at surgery was 10.3 ± 3.9 years. The average preoperative scoliosis curve was 61.3 ± 13.8°, and the average preoperative kyphosis curve was 39.8 ± 19.7°. The average postoperative scoliosis and kyphosis curves were 29.7 ± 10.7° and 21.0 ± 13.5°, respectively. The most recent follow-up scoliosis and kyphosis curves were 43.4 ± 17.3° and 29.4 ± 18.9°, respectively. There was no significant difference in the correction angle (either coronal or sagittal), and there was no significant difference in the loss of sagittal correction between the pedicle screw construct group and the hybrid construct group. However, the patients who received pedicle screw constructs had significantly less loss of coronal correction (P < .05). Two patients with posterior instrumentation, one with an all-hook construct and the other with a hybrid construct, required surgical revision because of progression of deformity. It is difficult to intraoperatively correct dystrophic deformity and to maintain this correction after surgery. Combined anterior release/fusion and posterior fusion using either a pedicle screw construct or a hybrid construct provide similar curve corrections both sagittally and coronally. After long-term follow-up, sagittal correction was maintained with both constructs. However, patients treated with posterior instrumentation using pedicle screw constructs had significantly less loss of coronal correction. PMID:28562548

Mutagenicity testing with transgenic mice. Part I: Comparison with the mouse bone marrow micronucleus test

PubMed Central

Wahnschaffe, U; Bitsch, A; Kielhorn, J; Mangelsdorf, I

2005-01-01

As part of a larger literature study on transgenic animals in mutagenicity testing, test results from the transgenic mutagenicity assays (lacI model; commercially available as the Big Blue® mouse, and the lacZ model; commercially available as the Muta™Mouse), were compared with the results on the same substances in the more traditional mouse bone marrow micronucleus test. 39 substances were found which had been tested in the micronucleus assay and in the above transgenic mouse systems. Although, the transgenic animal mutation assay is not directly comparable with the micronucleus test, because different genetic endpoints are examined: chromosome aberration versus gene mutation, the results for the majority of substances were in agreement. Both test systems, the transgenic mouse assay and the mouse bone marrow micronucleus test, have advantages and they complement each other. However, the transgenic animal assay has some distinct advantages over the micronucleus test: it is not restricted to one target organ and detects systemic as well as local mutagenic effects. PMID:15655069

In vivo characterization of a bigenic fluorescent mouse model of Alzheimer's disease with neurodegeneration.

PubMed

Crowe, Sarah E; Ellis-Davies, Graham C R

2013-07-01

The loss of cognitive function in Alzheimer's disease (AD) patients is strongly correlated with the loss of neurons in various regions of the brain. We have created a new fluorescent bigenic mouse model of AD by crossing "H-line" yellow fluorescent protein (YFP) mice with the 5xFAD mouse model, which we call the 5XY mouse model. The 5xFAD mouse has been shown to have significant loss of L5 pyramidal neurons by 12 months of age. These neurons are transgenically labeled with YFP in the 5XY mouse, which enable longitudinal imaging of structural changes. In the 5XY mice, we observed an appearance of axonal dystrophies, with two distinct morphologies in the early stages of the disease progression. Simple swelling dystrophies are transient in nature and are not directly associated with amyloid plaques. Rosette dystrophies are more complex structures that remained stable throughout all imaging sessions, and always surrounded an amyloid plaque. Plaque growth was followed over 4 weeks, and significant growth was seen between weekly imaging sessions. In addition to axonal dystrophy appearance and plaque growth, we were able to follow spine stability in 4-month old 5XY mice, which revealed no significant loss of spines. 5XY mice also showed a striking shrinkage of the neocortex at older ages (12-14 months). The 5XY mouse model may be a valuable tool for studying specific events in the degeneration of the neocortex, and may suggest new avenues for therapeutic intervention. Copyright © 2013 Wiley Periodicals, Inc.

Generation of 3D Skin Equivalents Fully Reconstituted from Human Induced Pluripotent Stem Cells (iPSCs)

PubMed Central

Guo, Zongyou; Liu, Liang; Higgins, Claire A.; Christiano, Angela M.

2013-01-01

Recent generation of patient-specific induced pluripotent stem cells (PS-iPSCs) provides significant advantages for cell- and gene-based therapy. Establishment of iPSC-based therapy for skin diseases requires efficient methodology for differentiating iPSCs into both keratinocytes and fibroblasts, the major cellular components of the skin, as well as the reconstruction of skin structures using these iPSC-derived skin components. We previously reported generation of keratinocytes from human iPSCs for use in the treatment of recessive dystrophic epidermolysis bullosa (RDEB) caused by mutations in the COL7A1 gene. Here, we developed a protocol for differentiating iPSCs into dermal fibroblasts, which also produce type VII collagen and therefore also have the potential to treat RDEB. Moreover, we generated in vitro 3D skin equivalents composed exclusively human iPSC-derived keratinocytes and fibroblasts for disease models and regenerative therapies for skin diseases, first demonstrating that iPSCs can provide the basis for modeling a human organ derived entirely from two different types of iPSC-derived cells. PMID:24147053

Twisted ribbon structure of paired helical filaments revealed by atomic force microscopy.

PubMed Central

Pollanen, M. S.; Markiewicz, P.; Bergeron, C.; Goh, M. C.

1994-01-01

Progressive deposition of phosphorylated tau into the paired helical filaments (PHF) that compose neurofibrillary tangles, dystrophic neurites, and neuropil threads is an obligate feature of Alzheimer's disease. The standard model of PHF structure, derived from electron microscopic studies, suggests that two 8- to 10-nm filaments each composed of three to four protofilaments are wound into a helix with a maximal diameter of -20 nm and a half period of 65 to 80 nm. However, recent vertical platinum-carbon replicas of PHF more closely resemble a thin helical ribbon without constitutive protofilaments. Here we report that native PHF imaged with an atomic force microscope appear as twisted ribbons rather than the generally accepted structure derived from electron microscopic studies. These data imply that the assembly of PHF is not due to the twisting of pair-wise filaments but rather the helical winding of self-associated tau molecules arranged into a flattened structure. Future structural models of PHF should be based on quantitative data obtained from imaging techniques, such as scanning probe microscopy, which do not require harsh specimen preparation procedures. Images Figure 1 PMID:8178938

Twisted ribbon structure of paired helical filaments revealed by atomic force microscopy.

PubMed

Pollanen, M S; Markiewicz, P; Bergeron, C; Goh, M C

1994-05-01

Progressive deposition of phosphorylated tau into the paired helical filaments (PHF) that compose neurofibrillary tangles, dystrophic neurites, and neuropil threads is an obligate feature of Alzheimer's disease. The standard model of PHF structure, derived from electron microscopic studies, suggests that two 8- to 10-nm filaments each composed of three to four protofilaments are wound into a helix with a maximal diameter of -20 nm and a half period of 65 to 80 nm. However, recent vertical platinum-carbon replicas of PHF more closely resemble a thin helical ribbon without constitutive protofilaments. Here we report that native PHF imaged with an atomic force microscope appear as twisted ribbons rather than the generally accepted structure derived from electron microscopic studies. These data imply that the assembly of PHF is not due to the twisting of pair-wise filaments but rather the helical winding of self-associated tau molecules arranged into a flattened structure. Future structural models of PHF should be based on quantitative data obtained from imaging techniques, such as scanning probe microscopy, which do not require harsh specimen preparation procedures.

Technique Selectively Represses Immune System

MedlinePlus

... from attacking myelin in a mouse model of multiple sclerosis. Dr David Furness, Wellcome Images. All rights reserved ... devised a way to successfully treat symptoms resembling multiple sclerosis in a mouse model. With further development, the ...

Lipopolysaccharide-induced endotoxemia in corn oil-preloaded mice causes an extended course of lung injury and repair and pulmonary fibrosis: A translational mouse model of acute respiratory distress syndrome.

PubMed

Wu, Chaomin; Evans, Colin E; Dai, Zhiyu; Huang, Xiaojia; Zhang, Xianming; Jin, Hua; Hu, Guochang; Song, Yuanlin; Zhao, You-Yang

2017-01-01

Acute respiratory distress syndrome (ARDS) is characterized by acute hypoxemia respiratory failure, bilateral pulmonary infiltrates, and pulmonary edema of non-cardiac origin. Effective treatments for ARDS patients may arise from experimental studies with translational mouse models of this disease that aim to delineate the mechanisms underlying the disease pathogenesis. Mouse models of ARDS, however, can be limited by their rapid progression from injured to recovery state, which is in contrast to the course of ARDS in humans. Furthermore, current mouse models of ARDS do not recapitulate certain prominent aspects of the pathogenesis of ARDS in humans. In this study, we developed an improved endotoxemic mouse model of ARDS resembling many features of clinical ARDS including extended courses of injury and recovery as well as development of fibrosis following i.p. injection of lipopolysaccharide (LPS) to corn oil-preloaded mice. Compared with mice receiving LPS alone, those receiving corn oil and LPS exhibited extended course of lung injury and repair that occurred over a period of >2 weeks instead of 3-5days. Importantly, LPS challenge of corn oil-preloaded mice resulted in pulmonary fibrosis during the repair phase as often seen in ARDS patients. In summary, this simple novel mouse model of ARDS could represent a valuable experimental tool to elucidate mechanisms that regulate lung injury and repair in ARDS patients.

Endometrial apoptosis and neutrophil infiltration during menstruation exhibits spatial and temporal dynamics that are recapitulated in a mouse model.

PubMed

Armstrong, Gregory M; Maybin, Jacqueline A; Murray, Alison A; Nicol, Moira; Walker, Catherine; Saunders, Philippa T K; Rossi, Adriano G; Critchley, Hilary O D

2017-12-12

Menstruation is characterised by synchronous shedding and restoration of tissue integrity. An in vivo model of menstruation is required to investigate mechanisms responsible for regulation of menstrual physiology and to investigate common pathologies such as heavy menstrual bleeding (HMB). We hypothesised that our mouse model of simulated menstruation would recapitulate the spatial and temporal changes in the inflammatory microenvironment of human menses. Three regulatory events were investigated: cell death (apoptosis), neutrophil influx and cytokine/chemokine expression. Well-characterised endometrial tissues from women were compared with uteri from a mouse model (tissue recovered 0, 4, 8, 24 and 48 h after removal of a progesterone-secreting pellet). Immunohistochemistry for cleaved caspase-3 (CC3) revealed significantly increased staining in human endometrium from late secretory and menstrual phases. In mice, CC3 was significantly increased at 8 and 24 h post-progesterone-withdrawal. Elastase + human neutrophils were maximal during menstruation; Ly6G + mouse neutrophils were maximal at 24 h. Human endometrial and mouse uterine cytokine/chemokine mRNA concentrations were significantly increased during menstrual phase and 24 h post-progesterone-withdrawal respectively. Data from dated human samples revealed time-dependent changes in endometrial apoptosis preceding neutrophil influx and cytokine/chemokine induction during active menstruation. These dynamic changes were recapitulated in the mouse model of menstruation, validating its use in menstrual research.

The STR/ort mouse model of spontaneous osteoarthritis - an update.

PubMed

Staines, K A; Poulet, B; Wentworth, D N; Pitsillides, A A

2017-06-01

Osteoarthritis is a degenerative joint disease and a world-wide healthcare burden. Characterized by cartilage degradation, subchondral bone thickening and osteophyte formation, osteoarthritis inflicts much pain and suffering, for which there are currently no disease-modifying treatments available. Mouse models of osteoarthritis are proving critical in advancing our understanding of the underpinning molecular mechanisms. The STR/ort mouse is a well-recognized model which develops a natural form of osteoarthritis very similar to the human disease. In this Review we discuss the use of the STR/ort mouse in understanding this multifactorial disease with an emphasis on recent advances in its genetics and its bone, endochondral and immune phenotypes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.