Expression profiling in exercised mdx suggests a role for extracellular proteins in the dystrophic muscle immune response

Author(s):  
Chantal A Coles ◽  
Lavinia Gordon ◽  
Liam C Hunt ◽  
Tracie Webster ◽  
Adam T Piers ◽  
...  

Abstract Duchenne muscular dystrophy (DMD) is a lethal muscle wasting disorder caused by mutations in the DMD gene that lead to the absence or severe reduction of dystrophin protein in muscle. The mdx mouse, also dystrophin deficient, is the model most widely used to study the pathology and test potential therapies, but the phenotype is milder than human DMD. This limits the magnitude and range of histological damage parameters and molecular changes that can be measured in pre-clinical drug testing. We used three weeks of voluntary wheel running to exacerbate the mdx phenotype. In mdx mice voluntary exercise increased the amount of damaged necrotic tissue and macrophage infiltration. Global gene expression profiling revealed that exercise induced additional and larger gene expression changes in mdx mice and the pathways most impacted by exercise were all related to immune function or cell-extracellular matrix (ECM) interactions. When we compared the matrisome and inflammation genes that were dysregulated in mdx with those commonly differentially expressed in DMD, we found the exercised mdx molecular signature more closely resembled that of DMD. These gene expression changes in the exercised mdx model thus provide more scope to assess the effects of pre-clinical treatments. Our gene profiling comparisons also highlighted upregulation of extracellular matrix proteins involved in innate immunity pathways, proteases that can release them, and downstream receptors and signalling molecules in exercised mdx and DMD, suggesting that the ECM could be a major source of pro-inflammatory molecules that trigger and maintain the immune response in dystrophic muscle.

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 853
Author(s):  
Keryn G. Woodman ◽  
Chantal A. Coles ◽  
Shireen R. Lamandé ◽  
Jason D. White

Duchenne muscular dystrophy (DMD) is a progressive fatal neuromuscular disorder with no cure. Therapies to restore dystrophin deficiency have been approved in some jurisdictions but long-term effectiveness is yet to be established. There is a need to develop alternative strategies to treat DMD. Resveratrol is a nutraceutical with anti-inflammatory properties. Previous studies have shown high doses (100–400 mg/kg bodyweight/day) benefit mdx mice. We treated 4-week-old mdx and wildtype mice with a lower dose of resveratrol (5 mg/kg bodyweight/day) for 15 weeks. Voluntary exercise was used to test if a lower dosage than previously tested could reduce exercise-induced damage where a greater inflammatory infiltrate is present. We found resveratrol promoted skeletal muscle hypertrophy in wildtype mice. In dystrophic muscle, resveratrol reduced exercise-induced muscle necrosis. Gene expression of immune cell markers, CD86 and CD163 were reduced; however, signalling targets associated with resveratrol’s mechanism of action including Sirt1 and NF-κB were unchanged. In conclusion, a lower dose of resveratrol compared to the dosage used by other studies reduced necrosis and gene expression of inflammatory cell markers in dystrophic muscle suggesting it as a therapeutic candidate for treating DMD.


2007 ◽  
Vol 97 (2) ◽  
pp. 384-397 ◽  
Author(s):  
J. L. Page ◽  
M. C. Johnson ◽  
K. M. Olsavsky ◽  
S. C. Strom ◽  
H. Zarbl ◽  
...  

1996 ◽  
Vol 80 (2) ◽  
pp. 670-679 ◽  
Author(s):  
A. Hayes ◽  
D. A. Williams

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.


Epigenomics ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1103-1119 ◽  
Author(s):  
Mariya A Smetanina ◽  
Alexander E Kel ◽  
Ksenia S Sevost'ianova ◽  
Igor V Maiborodin ◽  
Andrey I Shevela ◽  
...  

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1751-1751
Author(s):  
Animesh Pardanani ◽  
Rebecca R. Laborde ◽  
Terra L Lasho ◽  
Christy Finke ◽  
Alexey A. Leontovich ◽  
...  

Abstract Abstract 1751 Background: JAK inhibitors have significant palliative benefit in myelofibrosis (MF), mainly in the form of improved constitutional symptoms and reduced splenomegaly. Preliminary data suggests that CYT387, a JAK-1/2 inhibitor, also has the ability to produce anemia responses (ASH Annual Meeting, 2011). In general, the mechanism(s) underlying treatment effects of JAK inhibitors remain unclear but likely represent a drug-specific balance between anti-clonal activity and modulation of immuno cellular-cytokine pathways. We conducted a gene expression profiling (GEP) study using primary cells from MF patients undergoing therapy with CYT387 followed by correlation with clinical data. Methods: Study subjects were enrolled in the Phase-1/2 study of CYT387 treatment in patients with primary (PMF), post-polycythemia vera (PPMF) or post-essential thrombocythemia (PTMF) myelofibrosis. Paired research samples were collected; the time points were pre-study and 12 weeks after commencing study treatment. PBMCs were purified from whole blood by Ficoll separation; RNA was isolated from this cell fraction for GEP analysis. Gene expression profiles were generated using Illumnia Human HT-12 v4 microarray. Pair wise analysis was conducted using the Wilcoxon signed-rank test with a p-value cutoff of 0.05 to generate lists of differentially expressed genes between assigned groups. Pathway analysis was conducted to identify relevant pathways enriched for differentially expressed genes. Comprehensive plasma cytokine profiling was performed using Multiplex Bead-Based Luminex technology (Invitrogen, Carlsbad, CA). Results: Seventeen patients were studied based on sample availability; 11 (65%) mere male with median age of 66 years (range 53–85). Twelve (71%) were JAK2V617F mutation positive and the DIPSS-plus risk categorization was 10 (59%) high and 7 (41%) intermediate-2. All patients were evaluable for anemia response; 14 (82%) were red cell transfusion dependent at study start. Nine (53%) patients achieved anemia response by IWG-MRT criteria; of these, 8 patients achieved transfusion independence (minimum non-transfused hemoglobin level of 8 g/dL maintained for at least 12 weeks) and 1 had a sustained >2 g/dL increase in hemoglobin level above baseline. The initial pair wise analysis to identify differential patterns of gene expression compared pre- and post-treatment groups (Figure 1A). This revealed a cluster of significantly (p <0.05) down-regulated genes (minimum 2-fold; median 17-fold) following treatment (displayed in green; upper left quadrant). Pathway enrichment analysis revealed significant associations of these genes with cytokine regulation of immune response, cell proliferation, chemotaxis and cytoskeleton remodeling. We then conducted a pair wise analysis of anemia responders versus non-responders; this revealed a predominance of over expressed gene targets (median 35-fold) in the anemia responder group (Figure 1B) (displayed in red; upper right quadrant). Similar pathway analysis identified enrichment for genes involved in immune system function in this cluster. Conclusions: The current preliminary analysis suggests that genes relevant to immune response-cytokine pathways are significantly over expressed in patients who achieve anemia response following CYT387 therapy. This further suggests a dominant immune component that underpins ineffective hematopoiesis in responding patients. On the basis of broad treatment-related changes in gene expression we suggest that an important component of CYT387's treatment effect is down regulation of these dysregulated pathways. Ongoing studies include validation of select gene targets which will be tested prospectively in future treatment protocols, as well as correlation of gene expression with circulating cytokine-chemokine levels. Disclosures: Pardanani: Bristol-Myers Squibb: Clinical trial support, Clinical trial support Other; YM BioSciences: Clinical trial support, Clinical trial support Other; Sanofi-Aventis: Clinical trial support Other. Off Label Use: Data from Phase −1/2 study of CYT387 use in myelofibrosis is mentioned.


1999 ◽  
Vol 144 (6) ◽  
pp. 1259-1270 ◽  
Author(s):  
McRae W. Williams ◽  
Robert J. Bloch

We used immunofluorescence techniques and confocal imaging to study the organization of the membrane skeleton of skeletal muscle fibers of mdx mice, which lack dystrophin. β-Spectrin is normally found at the sarcolemma in costameres, a rectilinear array of longitudinal strands and elements overlying Z and M lines. However, in the skeletal muscle of mdx mice, β-spectrin tends to be absent from the sarcolemma over M lines and the longitudinal strands may be disrupted or missing. Other proteins of the membrane and associated cytoskeleton, including syntrophin, β-dystroglycan, vinculin, and Na,K-ATPase are also concentrated in costameres, in control myofibers, and mdx muscle. They also distribute into the same altered sarcolemmal arrays that contain β-spectrin. Utrophin, which is expressed in mdx muscle, also codistributes with β-spectrin at the mutant sarcolemma. By contrast, the distribution of structural and intracellular membrane proteins, including α-actinin, the Ca-ATPase and dihydropyridine receptors, is not affected, even at sites close to the sarcolemma. Our results suggest that in myofibers of the mdx mouse, the membrane- associated cytoskeleton, but not the nearby myoplasm, undergoes widespread coordinated changes in organization. These changes may contribute to the fragility of the sarcolemma of dystrophic muscle.


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