scholarly journals Hematopoietic Prostaglandin D Synthase Inhibitor PK007 Decreases Muscle Necrosis in DMD mdx Model Mice

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 994
Author(s):  
Sai Yarlagadda ◽  
Christina Kulis ◽  
Peter G. Noakes ◽  
Mark L. Smythe
Keyword(s):  
Mouse Model ◽  
Creatine Kinase Activity ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Prostaglandin D2 ◽  
Muscle Creatine Kinase ◽  
Progressive Muscle Weakness ◽  
Prostaglandin D Synthase ◽  
Muscle Necrosis ◽  
Synthase Inhibitor

Duchenne muscular dystrophy (DMD) is characterized by progressive muscle weakness and wasting due to the lack of dystrophin protein. The acute phase of DMD is characterized by muscle necrosis and increased levels of the pro-inflammatory mediator, prostaglandin D2 (PGD2). Inhibiting the production of PGD2 by inhibiting hematopoietic prostaglandin D synthase (HPGDS) may alleviate inflammation and decrease muscle necrosis. We tested our novel HPGDS inhibitor, PK007, in the mdx mouse model of DMD. Our results show that hindlimb grip strength was two-fold greater in the PK007-treated mdx group, compared to untreated mdx mice, and displayed similar muscle strength to strain control mice (C57BL/10ScSn). Histological analyses showed a decreased percentage of regenerating muscle fibers (~20% less) in tibialis anterior (TA) and gastrocnemius muscles and reduced fibrosis in the TA muscle in PK007-treated mice. Lastly, we confirmed that the DMD blood biomarker, muscle creatine kinase activity, was also reduced by ~50% in PK007-treated mdx mice. We conclude that our HPGDS inhibitor, PK007, has effectively reduced muscle inflammation and fibrosis in a DMD mdx mouse model.

Muscle genome-wide expression profiling during disease evolution in mdx mice

2009 ◽  
Vol 37 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Mario Marotta ◽  
Claudia Ruiz-Roig ◽  
Yaris Sarria ◽  
Jose Luis Peiro ◽  
Fatima Nuñez ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Genetic Defect ◽  
Strong Relationship ◽  
Pcr Analysis ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Matrix Remodeling ◽  
Disease Evolution ◽  
Genome Wide ◽  
Muscle Necrosis

Mdx mice show a milder phenotype than Duchenne patients despite bearing an analogous genetic defect. Our aim was to sort out genes, differentially expressed during the evolution of skeletal muscle mdx mouse disease, to elucidate the mechanisms by which these animals overcome the lack of dystrophin. Genome-wide microarray-based gene expression analysis was carried out at 3 wk and 1.5 and 3 mo of life. Candidate genes were selected by comparing: 1) mdx vs. controls at each point in time, and 2) mdx mice and 3) control mice among the three points in time. The first analysis showed a strong upregulation (96%) of inflammation-related genes and in >75% of genes related to cell adhesion, muscle structure/regeneration, and extracellular matrix remodeling during mdx disease evolution. Lgals3, Postn, Ctss, and Sln genes showed the strongest variations. The analysis performed among points in time demonstrated significant changes in Ecm1, Spon1, Thbs1, Csrp3, Myo10, Pde4b, and Adamts-5 exclusively during mdx mice lifespan. RT-PCR analysis of Postn, Sln, Ctss, Thbs1, Ecm1, and Adamts-5 expression from 3 wk to 9 mo, confirmed microarray data and demonstrated variations beyond 3 mo of age. A high-confidence functional network analysis demonstrated a strong relationship between them and showed two main subnetworks, having Dmd- Utrn- Myo10 and Adamts5- Thbs1- Spon1-Postn as principal nodes, which are functionally linked to Abca1, Actn4, Crebbp, Csrp3, Lama1, Lama3, Mical2, Mical3, Myf6, Pxn, and Sparc genes. Candidate genes may participate in the decline of muscle necrosis in mdx mice and could be considered potential therapeutic targets for Duchenne patients.

scholarly journals Metabolomic Analyses Reveal Extensive Progenitor Cell Deficiencies in a Mouse Model of Duchenne Muscular Dystrophy

Metabolites ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 61 ◽  
Author(s):  
Josiane Joseph ◽  
Dong Cho ◽  
Jason Doles
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mouse Model ◽  
Progenitor Cell ◽  
Treatment Options ◽  
Cell Types ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Metabolic Alterations ◽  
Potential Contributor

Duchenne muscular dystrophy (DMD) is a musculoskeletal disorder that causes severe morbidity and reduced lifespan. Individuals with DMD have an X-linked mutation that impairs their ability to produce functional dystrophin protein in muscle. No cure exists for this disease and the few therapies that are available do not dramatically delay disease progression. Thus, there is a need to better understand the mechanisms underlying DMD which may ultimately lead to improved treatment options. The muscular dystrophy (MDX) mouse model is frequently used to explore DMD disease traits. Though some studies of metabolism in dystrophic mice exist, few have characterized metabolic profiles of supporting cells in the diseased environment. Using nontargeted metabolomics we characterized metabolic alterations in muscle satellite cells (SCs) and serum of MDX mice. Additionally, live-cell imaging revealed MDX-derived adipose progenitor cell (APC) defects. Finally, metabolomic studies revealed a striking elevation of acylcarnitines in MDX APCs, which we show can inhibit APC proliferation. Together, these studies highlight widespread metabolic alterations in multiple progenitor cell types and serum from MDX mice and implicate dystrophy-associated metabolite imbalances in APCs as a potential contributor to adipose tissue disequilibrium in DMD.

Talin, vinculin and DRP (utrophin) concentrations are increased at mdx myotendinous junctions following onset of necrosis

1994 ◽  
Vol 107 (6) ◽  
pp. 1477-1483 ◽  
Author(s):  
D.J. Law ◽  
D.L. Allen ◽  
J.G. Tidball
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Cytoskeletal Proteins ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Myotendinous Junction ◽  
Glycoprotein Complex ◽  
Transmembrane Glycoprotein ◽  
Muscle Necrosis ◽  
Myotendinous Junctions

Duchenne muscular dystrophy (DMD) and the myopathy seen in the mdx mouse both result from absence of the protein dystrophin. Structural similarities between dystrophin and other cytoskeletal proteins, its enrichment at myotendinous junctions, and its indirect association with laminin mediated by a transmembrane glycoprotein complex suggest that one of dystrophin's functions in normal muscle is to form one of the links between the actin cytoskeleton and the extracellular matrix. Unlike Duchenne muscular dystrophy patients, mdx mice suffer only transient muscle necrosis, and are able to regenerate damaged muscle tissue. The present study tests the hypothesis that mdx mice partially compensate for dystrophin's absence by upregulating one or more dystrophin-independent mechanisms of cytoskeleton-membrane association. Quantitative analysis of immunoblots of adult mdx muscle samples showed an increase of approximately 200% for vinculin and talin, cytoskeletal proteins that mediate thin filament-membrane interactions at myotendinous junctions. Blots also showed an increase (143%) in the dystrophin-related protein called utrophin, another myotendinous junction constituent, which may be able to substitute for dystrophin directly. Muscle samples from 2-week-old animals, a period immediately preceding the onset of muscle necrosis, showed no significant differences in protein concentration between mdx and controls. Quantitative analyses of confocal images of myotendinous junctions from mdx and control muscles show significantly higher concentrations of talin and vinculin at the myotendinous junctions of mdx muscle. These findings indicate that mdx mice may compensate in part for the absence of dystrophin by increased expression of other molecules that subsume dystrophin's mechanical function.

Mechanics of dystrophin deficient skeletal muscles in very young mice and effects of age

2021 ◽  
Author(s):  
Michael A. Lopez ◽  
Sherina Bontiff ◽  
Mary Adeyeye ◽  
Aziz I Shaibani ◽  
Matthew S. Alexander ◽  
...  
Keyword(s):  
Skeletal Muscles ◽  
Force Production ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Fiber Direction ◽  
Transverse Fiber ◽  
Muscle Necrosis ◽  
Relaxation Curves ◽  
Passive Mechanics

The MDX mouse is an animal model of Duchenne muscular dystrophy, a human disease marked by an absence of the cytoskeletal protein, dystrophin. We hypothesized that (1) dystrophin serves a complex mechanical role in skeletal muscles by contributing to passive compliance, viscoelastic properties, and contractile force production and (2) age is a modulator of passive mechanics of skeletal muscles of the MDX mouse. Using an in vitro biaxial mechanical testing apparatus, we measured passive length-tension relationships in the muscle fiber direction as well as transverse to the fibers, viscoelastic stress-relaxation curves, and isometric contractile properties. To avoid confounding secondary effects of muscle necrosis, inflammation, and fibrosis, we used very young 3-week-old mice whose muscles reflected the pre-fibrotic and pre-necrotic state. Compared to controls, 1) muscle extensibility and compliance were greater in both along fiber direction and transverse to fiber direction in MDX mice and 2) the relaxed elastic modulus was greater in dystrophin-deficient diaphragms. Furthermore, isometric contractile muscle stress was reduced in the presence and absence of transverse fiber passive stress. We also examined the effect of age on the diaphragm length-tension relationships and found that diaphragm muscles from 9-months old MDX mice were significantly less compliant and less extensible than those of muscles from very young MDX mice. Our data suggest that the age of the MDX mouse is a determinant of the passive mechanics of the diaphragm; in the pre-fibrotic/pre-necrotic stage, muscle extensibility and compliance, as well as viscoelasticity, and muscle contractility are altered by loss of dystrophin.

Evaluation of micro-dystrophin based and dystrophin-independent AAV gene therapies for Duchenne Muscular Dystrophy

2020 ◽  
Author(s):  
◽  
Lakmini P. Wasala
Keyword(s):  
Muscular Dystrophy ◽  
Mouse Model ◽  
Left Ventricular ◽  
Upstream Region ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Wild Type ◽  
Ww Domain ◽  
Gene Therapies ◽  
Complete Deletion

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI-COLUMBIA AT REQUEST OF AUTHOR.] Duchenne Muscular dystrophy (DMD) is the most common, progressive childhood muscular dystrophy with an X-linked inheritance. The major cause of the disease is the mutations in the dystrophin gene which results in the absence of a functional dystrophin protein. Currently there is no permanent cure for DMD. Many genetic and pharmacological approaches have resulted in tremendous improvements in animal models and advanced the mission of finding a permanent cure for DMD. Adeno associated virus (AAV) mediated micro-dystrophin gene therapy is the most promising approach to treat patients irrespective of their type of mutations. Dystrophin independent AAV gene therapies have also shown encouraging data in animal models in subsiding DMD pathology. In engineering micro-dystrophins, it is important to include the most essential regions or domains to achieve maximum benefits, that fits into the AAV. Our goal was to understand the impact of hinge 1 (H1) and hinge 4 (H4) regions in the function of a micro-dystrophin ([micro]Dys) construct. Two novel micro-dystrophins were engineered by complete deletion of either hinge 1 or hinge 4 and packaged in AAV9. Three separate groups of 3-month old male mdx4cv mice tibialis anterior muscles were injected with each novel AAV.[micro]Dys vector and parent vector separately. Three months post injection TA muscle contractile properties were evaluated. Hinge 1 deletion was tolerated by parent [micro]Dys although deletion of hinge 4 reduced the functional performance. Hinge domains played an important part in localization of [micro]Dys to the sarcolemma. Deletion of hinge 1 did not interfere with normal sarcolemmal localization whereas complete deletion of hinge 4 failed to localize [micro]Dys. Both novel [micro]Dys were able to restore dystrophin associated glycoprotein complex (DGC) proteins to the sarcolemma in dystrophin positive fibers. To further analyze which region of hinge 4 that could be devoid of [micro]Dys, we engineered additional four novel [micro]Dys with modifications in only the hinge 4 region, while hinge 1 is intact. Deletion of the region upstream of WW domain was shown to enhance the [micro]Dys function, and any other deletion reduced the performance of [micro]Dys. We also found that deletion of upstream region of WW domain did not interfere in [micro]Dys localization to sarcolemma and other deletions failed to fully restore [micro]Dys to sarcolemma. Next, we developed another micro-dystrophin that combined complete deletion of hinge 1 with deletion of the upstream region of WW domain. This latest [micro]Dys showed to preserve the muscle tetanic force similar to parent [micro]Dys. This is the first study of in-depth evaluation of the importance of the presence or absence of hinge 1 and hinge 4 in the functional performance of micro-dystrophin. These data provide valuable insights in engineering novel micro-dystrophins. One of the major cellular networks affected in DMD is the mitochondrial function and subsequent metabolic homeostasis. PGC-1a is a key transcriptional co-activator of mitochondrial biogenesis and oxidative metabolism in muscle. PGC-1a has previously studied in improving skeletal muscle pathology in mdx mouse model although its therapeutic effects on mdx cardiac pathology has not been evaluated. We delivered AAV9.PGC-1a vector systemically via the tail vein of 12-month old female mdx mice and 4-months post injected we evaluated the left ventricular hemodynamic parameters. AAV.PGC-1a treated mice showed normalization of several left ventricular hemodynamic parameters to the wild type level. Pathway protein analysis revealed overexpression of PGC-1a, resulted in the increased expression of several major transcription factors in oxidative phosphorylation, mitochondrial biogenesis, fatty acid metabolism, electron transport chain. This is the first study to report that cardiac hemodynamic improvements in 4-month treatment of AAV.PGC-1a in aged mdx mice. This study also shows that without replacing dystrophin, PGC-1a overexpression alone resulted in improving cardiac performance by improving cardiac metabolism in mdx mice. The data provided useful insights developing novel therapies in improving DMD cardiomyopathy. In the final study we used another novel isoform of PGC-1a family, PGC-1a4 which has shown to be expressed during resistance training and regulates muscle hypertrophy. As muscle hypertrophy induction has previously shown to be therapeutically effective in mdx mouse model, we delivered AAV.PGC-1a4 systemically and as intramuscular injections. In the mdx4cv mouse model, we could not overexpress the PGC-1a4 protein above the endogenous levels and no cardiac or skeletal muscle function was improved. Although intramuscular delivery of AAV.PGC-1a4 in wild type mice showed overexpression of PGC-1a4 protein above endogenous levels. Wild type mice showed improvements in eccentric force, although muscle cross sectional area or muscle weight did not reach statistical significance. Our study concluded that PGC-1a4 is not a suitable candidate for AAV gene therapy for DMD. In summary, this dissertation provides important discoveries related to development of next-generation micro-dystrophin vectors and dystrophin-independent AAV gene therapies.

Quantitative assessment of muscle damage in the mdx mouse model of Duchenne muscular dystrophy using polarization-sensitive optical coherence tomography

2013 ◽  
Vol 115 (9) ◽  
pp. 1393-1401 ◽  
Author(s):  
Xiaojie Yang ◽  
Lixin Chin ◽  
Blake R. Klyen ◽  
Tea Shavlakadze ◽  
Robert A. McLaughlin ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Muscle Tissue ◽  
Volume Fraction ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Optical Coherence ◽  
Histological Sections ◽  
Muscle Necrosis

Minimally invasive, high-resolution imaging of muscle necrosis has the potential to aid in the assessment of diseases such as Duchenne muscular dystrophy. Undamaged muscle tissue possesses high levels of optical birefringence due to its anisotropic ultrastructure, and this birefringence decreases when the tissue undergoes necrosis. In this study, we present a novel technique to image muscle necrosis using polarization-sensitive optical coherence tomography (PS-OCT). From PS-OCT scans, our technique is able to quantify the birefringence in muscle tissue, generating an image indicative of the tissue ultrastructure, with areas of abnormally low birefringence indicating necrosis. The technique is demonstrated on excised skeletal muscles from exercised dystrophic mdx mice and control C57BL/10ScSn mice with the resulting images validated against colocated histological sections. The technique additionally gives a measure of the proportion (volume fraction) of necrotic tissue within the three-dimensional imaging field of view. The percentage necrosis assessed by this technique is compared against the percentage necrosis obtained from manual assessment of histological sections, and the difference between the two methods is found to be comparable to the interobserver variability of the histological assessment. This is the first published demonstration of PS-OCT to provide automated assessment of muscle necrosis.

scholarly journals Minimal Consequences of CMAH and DBA/2J Background on a FKRP Deficient Model

2020 ◽  
pp. 1-9
Author(s):  
Camille Vaubourg ◽  
Evelyne Gicquel ◽  
Isabelle Richard ◽  
William Lostal ◽  
Jessica Bellec
Keyword(s):  
Mouse Model ◽  
Genetic Diseases ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Genetic Modifiers ◽  
Mild Phenotype ◽  
Mouse Phenotype ◽  
Progressive Loss ◽  
The One ◽  
Genome Modifications

Background: Muscular dystrophies (MD) are a large group of genetic diseases characterized by a progressive loss of muscle. The Latent TGFβ Binding Protein 4 (LTBP4) in the DBA/2 background and the Cytidine Monophosphate-sialic Acid Hydroxylase (CMAH) proteins were previously identified as genetic modifiers in severe MD. Objective: We investigated whether these modifiers could also influence a mild phenotype such as the one observed in a mouse model of Limb-Girdle MD2I (LGMD2I). Methods: The FKRPL276I mouse model was backcrossed onto the DBA/2 background, and in separate experiments the Cmah gene was inactivated in FKRPL276I mice by crossing with a Cmah-/- mouse and selecting the double-mutants. The mdx mouse was used as control for these two genome modifications. Consequences at the histological level as well as quantification of expression level by RT-qPCR of genes relevant for muscular dystrophy were then performed. Results: We observed minimal to no effect of the DBA/2 background on the mild FKRPL276I mouse phenotype, while this same background was previously shown to increase inflammation and fibrosis in the mdx mouse. Similarly, the Cmah-/- deletion had no observable effect on the FKRPL276I mouse phenotype whereas it was seen to increase features of regeneration in mdx mice. Conclusions: These modifiers were not observed to impact the severity of the presentation of the mild FKRPL276I model. An interesting association of the CMAH modifier with the regeneration process in the mdx model was seen and sheds new light on the influence of this protein on the dystrophic phenotype.

Effect of propylthiouracil-induced hypothyroidism on the onset of skeletal muscle necrosis in dystrophin-deficient mdx mice

1998 ◽  
Vol 95 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Anne McARDLE ◽  
Timothy R. HELLIWELL ◽  
Geoffrey J. BECKETT ◽  
Mariana CATAPANO ◽  
Anthony DAVIS ◽  
...  
Keyword(s):  
Endocrine System ◽  
Dystrophin Gene ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Postnatal Maturation ◽  
Hormone Synthesis ◽  
The Third ◽  
Serum T4 ◽  
Muscle Necrosis ◽  
Insight Into

1.Duchenne and Becker muscular dystrophies are X-linked disorders caused by defects in muscle dystrophin. The mdx mouse is an animal model for Duchenne muscular dystrophy which has a point mutation in the dystrophin gene, resulting in little (< 3%) or no expression of dystrophin in muscle. Mdx mice show a characteristic pattern of muscle necrosis and regeneration. Muscles are normal until the third postnatal week when widespread necrosis commences. This is followed by muscle regeneration, with the persistence of centrally nucleated fibres. 2.This work has examined the hypothesis that the onset of this muscle necrosis is associated with postnatal maturation of the thyroid endocrine system and that pharmacological inhibition of thyroid hormone synthesis delays the onset of muscle necrosis. 3.Serum T4 and T3 concentrations of mice were found to rise immediately before the onset of muscle necrosis in the mdx mouse, and induction of hypothyroidism by treatment of animals with propylthiouracil was found to delay the onset of muscle necrosis. 4.The results provide the first demonstration of experimental delay of muscle necrosis by manipulation of the endocrine system in muscle lacking dystrophin, and provide a novel insight into the way in which a lack of dystrophin interacts with postnatal development to precipitate muscle necrosis in the mdx mouse.

scholarly journals Lipocalin 2 Influences Bone and Muscle Phenotype in the MDX Mouse Model of Duchenne Muscular Dystrophy

2022 ◽  
Vol 23 (2) ◽  
pp. 958
Author(s):  
Marco Ponzetti ◽  
Argia Ucci ◽  
Antonio Maurizi ◽  
Luca Giacchi ◽  
Anna Teti ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Bone Loss ◽  
Mouse Model ◽  
Mononuclear Cells ◽  
Serum Levels ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Muscle Fibres ◽  
Lipocalin 2

Lipocalin 2 (Lcn2) is an adipokine involved in bone and energy metabolism. Its serum levels correlate with bone mechanical unloading and inflammation, two conditions representing hallmarks of Duchenne Muscular Dystrophy (DMD). Therefore, we investigated the role of Lcn2 in bone loss induced by muscle failure in the MDX mouse model of DMD. We found increased Lcn2 serum levels in MDX mice at 1, 3, 6, and 12 months of age. Consistently, Lcn2 mRNA was higher in MDX versus WT muscles. Immunohistochemistry showed Lcn2 expression in mononuclear cells between muscle fibres and in muscle fibres, thus confirming the gene expression results. We then ablated Lcn2 in MDX mice, breeding them with Lcn2−/− mice (MDXxLcn2−/−), resulting in a higher percentage of trabecular volume/total tissue volume compared to MDX mice, likely due to reduced bone resorption. Moreover, MDXxLcn2−/− mice presented with higher grip strength, increased intact muscle fibres, and reduced serum creatine kinase levels compared to MDX. Consistently, blocking Lcn2 by treating 2-month-old MDX mice with an anti-Lcn2 monoclonal antibody (Lcn2Ab) increased trabecular volume, while reducing osteoclast surface/bone surface compared to MDX mice treated with irrelevant IgG. Grip force was also increased, and diaphragm fibrosis was reduced by the Lcn2Ab. These results suggest that Lcn2 could be a possible therapeutic target to treat DMD-induced bone loss.

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