Reducing sarcolipin expression improves muscle metabolism in mdx mice

2022 ◽  
Author(s):  
Rekha Balakrishnan ◽  
Satvik Mareedu ◽  
Gopal J. Babu
Keyword(s):  
Oxidative Stress ◽  
Muscle Metabolism ◽  
Muscle Pathology ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Histopathological Analysis ◽  
Protein Levels ◽  
Insulin Tolerance ◽  
Complex Protein ◽  
Muscle Wasting Disease

Duchenne muscular dystrophy (DMD) is an inherited muscle wasting disease. Metabolic impairments and oxidative stress are major secondary mechanisms that severely worsen muscle function in DMD. Here, we sought to determine whether germline reduction or ablation of sarcolipin (SLN), an inhibitor of sarco/endoplasmic reticulum (SR) Ca2+ ATPase (SERCA) improves muscle metabolism and ameliorates muscle pathology in the mdx mouse model of DMD. Glucose and insulin tolerance tests show that glucose clearance rate and insulin sensitivity were improved in the SLN haploinsufficient mdx (mdx:sln+/-) and SLN deficient mdx (mdx:sln-/-) mice. The histopathological analysis shows that fibrosis and necrosis were significantly reduced in muscles of mdx:sln+/- and mdx:sln-/- mice. SR Ca2+ uptake, mitochondrial complex protein levels, complex activities, mitochondrial Ca2+ uptake and release, and mitochondrial metabolism were significantly improved and, lipid peroxidation and protein carbonylation were reduced in the muscles of mdx:sln+/- and mdx:sln-/- mice. These data demonstrate that reduction or ablation of SLN expression can improve muscle metabolism, reduce oxidative stress, decrease muscle pathology, and protects the mdx mice from glucose intolerance.

scholarly journals A Blood Biomarker for Duchenne Muscular Dystrophy Shows That Oxidation State of Albumin Correlates with Protein Oxidation and Damage in Mdx Muscle

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1241
Author(s):  
Basma A. Al-Mshhdani ◽  
Miranda D. Grounds ◽  
Peter G. Arthur ◽  
Jessica R. Terrill
Keyword(s):  
Oxidative Stress ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Blood Protein ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Thiol Oxidation ◽  
Plasma Albumin ◽  
Blood Biomarker ◽  
Muscle Wasting Disease

Duchenne muscular dystrophy (DMD) is a severe X-linked muscle wasting disease with no cure. While the precise mechanisms of progressive dystropathology remain unclear, oxidative stress caused by excessive generation of oxidants is strongly implicated. Blood biomarkers that could track oxidant levels in tissues would be valuable to measure the effectiveness of clinical treatments for DMD; our research has focused on developing such biomarkers. One target of oxidants that has the potential to be harnessed as a clinical biomarker is the thiol side chain of cysteine 34 (Cys34) of the blood protein albumin. This study using the mdx mouse model of DMD shows that in plasma, albumin Cys34 undergoes thiol oxidation and these changes correlate with levels of protein thiol oxidation and damage of the dystrophic muscles. A comparison with the commonly used biomarker protein carbonylation, confirmed that albumin thiol oxidation is the more sensitive plasma biomarker of oxidative stress occurring in muscle tissue. We show that plasma albumin oxidation reflects muscle dystropathology, as increased after exercise and decreased after taurine treatment of mdx mice. These data support the use of albumin thiol oxidation as a blood biomarker of dystropathology to assist with advancing clinical development of therapies for DMD.

scholarly journals BETs inhibition attenuates oxidative stress and preserves muscle integrity in Duchenne muscular dystrophy

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Marco Segatto ◽  
Roberta Szokoll ◽  
Raffaella Fittipaldi ◽  
Cinzia Bottino ◽  
Lorenzo Nevi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mdx Mouse ◽  
Early Event ◽  
Dystrophic Muscle ◽  
Protein Levels ◽  
Bet Inhibitors ◽  
Ros Metabolism

AbstractDuchenne muscular dystrophy (DMD) affects 1 in 3500 live male births. To date, there is no effective cure for DMD, and the identification of novel molecular targets involved in disease progression is important to design more effective treatments and therapies to alleviate DMD symptoms. Here, we show that protein levels of the Bromodomain and extra-terminal domain (BET) protein BRD4 are significantly increased in the muscle of the mouse model of DMD, the mdx mouse, and that pharmacological inhibition of the BET proteins has a beneficial outcome, tempering oxidative stress and muscle damage. Alterations in reactive oxygen species (ROS) metabolism are an early event in DMD onset and they are tightly linked to inflammation, fibrosis, and necrosis in skeletal muscle. By restoring ROS metabolism, BET inhibition ameliorates these hallmarks of the dystrophic muscle, translating to a beneficial effect on muscle function. BRD4 direct association to chromatin regulatory regions of the NADPH oxidase subunits increases in the mdx muscle and JQ1 administration reduces BRD4 and BRD2 recruitment at these regions. JQ1 treatment reduces NADPH subunit transcript levels in mdx muscles, isolated myofibers and DMD immortalized myoblasts. Our data highlight novel functions of the BET proteins in dystrophic skeletal muscle and suggest that BET inhibitors may ameliorate the pathophysiology of DMD.

scholarly journals Purinergic receptor X7 is a key modulator of metabolic oxidative stress-mediated autophagy and inflammation in experimental nonalcoholic steatohepatitis

2013 ◽  
Vol 305 (12) ◽  
pp. G950-G963 ◽  
Author(s):  
Suvarthi Das ◽  
Ratanesh Kumar Seth ◽  
Ashutosh Kumar ◽  
Maria B. Kadiiska ◽  
Gregory Michelotti ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nonalcoholic Steatohepatitis ◽  
P2x7 Receptor ◽  
Molecular Mechanisms ◽  
Purinergic Receptor ◽  
Receptor Gene ◽  
Receptor Expression ◽  
Histopathological Analysis ◽  
Protein Levels ◽  
Metabolic Oxidative Stress

Recent studies indicate that metabolic oxidative stress, autophagy, and inflammation are hallmarks of nonalcoholic steatohepatitis (NASH) progression. However, the molecular mechanisms that link these important events in NASH remain unclear. In this study, we investigated the mechanistic role of purinergic receptor X7 (P2X7) in modulating autophagy and resultant inflammation in NASH in response to metabolic oxidative stress. The study uses two rodent models of NASH. In one of them, a CYP2E1 substrate bromodichloromethane is used to induce metabolic oxidative stress and NASH. Methyl choline-deficient diet feeding is used for the other NASH model. CYP2E1 and P2X7 receptor gene-deleted mice are used to establish their roles in regulating metabolic oxidative stress and autophagy. Autophagy gene expression, protein levels, confocal microscopy based-immunolocalization of lysosome-associated membrane protein (LAMP)2A and histopathological analysis were performed. CYP2E1-dependent metabolic oxidative stress induced increases in P2X7 receptor expression and chaperone-mediated autophagy markers LAMP2A and heat shock cognate 70 but caused depletion of light chain 3 isoform B (LC3B) protein levels. P2X7 receptor gene deletion significantly decreased LAMP2A and inflammatory indicators while significantly increasing LC3B protein levels compared with wild-type mice treated with bromodichloromethane. P2X7 receptor-deleted mice were also protected from NASH pathology as evidenced by decreased inflammation and fibrosis. Our studies establish that P2X7 receptor is a key regulator of autophagy induced by metabolic oxidative stress in NASH, thereby modulating hepatic inflammation. Furthermore, our findings presented here form a basis for P2X7 receptor as a potential therapeutic target in the treatment for NASH.

scholarly journals Treatment of Dystrophic mdx Mice with an ADAMTS-5 Specific Monoclonal Antibody Increases the Ex Vivo Strength of Isolated Fast Twitch Hindlimb Muscles

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 416 ◽  
Author(s):  
Alex Addinsall ◽  
Leonard Forgan ◽  
Natasha McRae ◽  
Rhys Kelly ◽  
Penny McDonald ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Ex Vivo ◽  
Fiber Type ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Protein Levels ◽  
Positive Effects ◽  
Hindlimb Muscles ◽  
Fiber Size ◽  
Fast Twitch

Aberrant extracellular matrix synthesis and remodeling contributes to muscle degeneration and weakness in Duchenne muscular dystrophy (DMD). ADAMTS-5, a secreted metalloproteinase with catalytic activity against versican, is implicated in myogenesis and inflammation. Here, using the mdx mouse model of DMD, we report increased ADAMTS-5 expression in dystrophic hindlimb muscles, localized to regions of regeneration and inflammation. To investigate the pathophysiological significance of this, 4-week-old mdx mice were treated with an ADAMTS-5 monoclonal antibody (mAb) or IgG2c (IgG) isotype control for 3 weeks. ADAMTS-5 mAb treatment did not reduce versican processing, as protein levels of the cleaved versikine fragment did not differ between hindlimb muscles from ADAMTS-5 mAb or IgG treated mdx mice. Nonetheless, ADAMTS-5 blockade improved ex vivo strength of isolated fast extensor digitorum longus, but not slow soleus, muscles. The underpinning mechanism may include modulation of regenerative myogenesis, as ADAMTS-5 blockade reduced the number of recently repaired desmin positive myofibers without affecting the number of desmin positive muscle progenitor cells. Treatment with the ADAMTS-5 mAb did not significantly affect markers of muscle damage, inflammation, nor fiber size. Altogether, the positive effects of ADAMTS-5 blockade in dystrophic muscles are fiber-type-specific and independent of versican processing.

Isoform-specific Na,K-ATPase and membrane cholesterol remodeling in motor endplates in distinct mouse models of myodystrophy

2020 ◽  
Vol 318 (5) ◽  
pp. C1030-C1041 ◽  
Author(s):  
Violetta V. Kravtsova ◽  
Elena V. Bouzinova ◽  
Alexander V. Chibalin ◽  
Vladimir V. Matchkov ◽  
Igor I. Krivoi
Keyword(s):  
Mrna Expression ◽  
Protein Content ◽  
Mouse Models ◽  
Experimental Models ◽  
Muscle Pathology ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Membrane Cholesterol ◽  
Membrane Transporter ◽  
Skeletal Muscle Function

Na,K-ATPase is a membrane transporter that is critically important for skeletal muscle function. Mdx and Bla/J mice are the experimental models of Duchenne muscular dystrophy and dysferlinopathy that are known to differ in the molecular mechanism of the pathology. This study examines the function of α1- and α2-Na,K-ATPase isozymes in respiratory diaphragm and postural soleus muscles from mdx and Bla/J mice compared with control С57Bl/6 mice. In diaphragm muscles, the motor endplate structure was severely disturbed (manifested by defragmentation) in mdx mice only. The endplate membrane of both Bla/J and mdx mice was depolarized due to specific loss of the α2-Na,K-ATPase electrogenic activity and its decreased membrane abundance. Total FXYD1 subunit (modulates Na,K-ATPase activity) abundance was decreased in both mouse models. However, the α2-Na,K-ATPase protein content as well as mRNA expression were specifically and significantly reduced only in mdx mice. The endplate membrane cholesterol redistribution was most pronounced in mdx mice. Soleus muscles from Bla/J and mdx mice demonstrated reduction of the α2-Na,K-ATPase membrane abundance and mRNA expression similar to the diaphragm muscles. In contrast to diaphragm, the α2-Na,K-ATPase protein content was altered in both Bla/J and mdx mice; membrane cholesterol re-distribution was not observed. Thus, the α2-Na,K-ATPase is altered in both Bla/J and mdx mouse models of chronic muscle pathology. However, despite some similarities, the α2-Na,K-ATPase and cholesterol abnormalities are more pronounced in mdx mice.

MicroRNA-206 is overexpressed in the diaphragm but not the hindlimb muscle of mdx mouse

2007 ◽  
Vol 293 (1) ◽  
pp. C451-C457 ◽  
Author(s):  
John J. McCarthy ◽  
Karyn A. Esser ◽  
Francisco H. Andrade
Keyword(s):  
Fold Increase ◽  
Transcript Level ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Dystrophic Muscle ◽  
Protein Levels ◽  
Mature Microrna ◽  
Hindlimb Muscle ◽  
Vitro Analysis

MicroRNAs are highly conserved, noncoding RNAs involved in posttranscriptional gene silencing. MicroRNAs have been shown to be involved in a range of biological processes, including myogenesis and muscle regeneration. The objective of this study was to test the hypothesis that microRNA expression is altered in dystrophic muscle, with the greatest change occurring, of the muscles examined, in the diaphragm. The expression of the muscle-enriched microRNAs was determined in the soleus, plantaris, and diaphragm muscles of control and dystrophin-deficient ( mdx) mice by semiquantitative PCR. In the soleus and plantaris, expression of the mature microRNA 133a (miR-133a) and miR-206, respectively, was decreased by ∼25%, whereas in the diaphragm, miR-206 expression increased by 4.5-fold relative to control. The increased expression of miR-206 in the mdx diaphragm was paralleled by a 4.4-fold increase in primary miRNA-206 (pri-miRNA-206) transcript level. Expression of Myod1 was elevated 2.7-fold only in the mdx diaphragm, consistent with an earlier finding demonstrating Myod1 can activate pri-miRNA-206 transcription. Transcript levels of Drosha and Dicer, major components of microRNA biogenesis pathway, were unchanged in mdx muscle, suggesting the pathway is not altered under dystrophic conditions. Previous in vitro analysis found miR-206 was capable of repressing utrophin expression; however, under dystrophic conditions, both utrophin transcript and protein levels were significantly increased by 69% and 3.9-fold, respectively, a finding inconsistent with microRNA regulation. These results are the first to report alterations in expression of muscle-enriched microRNAs in skeletal muscle of the mdx mouse, suggesting microRNAs may have a role in the pathophysiology of muscular dystrophy.

scholarly journals Investigating the Potential for Sulforaphane to Attenuate Gastrointestinal Dysfunction in mdx Dystrophic Mice

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4559
Author(s):  
Kristy Swiderski ◽  
Suzannah J. Read ◽  
Audrey S. Chan ◽  
Jin D. Chung ◽  
Jennifer Trieu ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Corn Oil ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
In Vivo Studies ◽  
Muscle Pathology ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Dystrophic Mice

Gastrointestinal (GI) dysfunction is an important, yet understudied condition associated with Duchenne muscular dystrophy (DMD), with patients reporting bloating, diarrhea, and general discomfort, contributing to a reduced quality of life. In the mdx mouse, the most commonly used mouse model of DMD, studies have confirmed GI dysfunction (reported as altered contractility and GI transit through the small and large intestine), associated with increased local and systemic inflammation. Sulforaphane (SFN) is a natural isothiocyanate with anti-inflammatory and anti-oxidative properties via its activation of Nrf2 signalling that has been shown to improve aspects of the skeletal muscle pathology in dystrophic mice. Whether SFN can similarly improve GI function in muscular dystrophy was unknown. Video imaging and spatiotemporal mapping to assess gastrointestinal contractions in isolated colon preparations from mdx and C57BL/10 mice revealed that SFN reduced contraction frequency when administered ex vivo, demonstrating its therapeutic potential to improve GI function in DMD. To confirm this in vivo, four-week-old male C57BL/10 and mdx mice received vehicle (2% DMSO/corn oil) or SFN (2 mg/kg in 2% DMSO/corn oil) via daily oral gavage five days/week for 4 weeks. SFN administration reduced fibrosis in the diaphragm of mdx mice but did not affect other pathological markers. Gene and protein analysis revealed no change in Nrf2 protein expression or activation of Nrf2 signalling after SFN administration and oral SFN supplementation did not improve GI function in mdx mice. Although ex vivo studies demonstrate SFN’s therapeutic potential for reducing colon contractions, in vivo studies should investigate higher doses and/or alternate routes of administration to confirm SFN’s potential to improve GI function in DMD.

Resveratrol improves muscle function but not oxidative capacity in young mdx mice

2014 ◽  
Vol 92 (3) ◽  
pp. 243-251 ◽  
Author(s):  
Bradley S. Gordon ◽  
Diana C. Delgado-Diaz ◽  
James Carson ◽  
Raja Fayad ◽  
L. Britt Wilson ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Muscle Function ◽  
Immune Cell ◽  
Oxidative Capacity ◽  
Post Treatment ◽  
Muscle Pathology ◽  
Mdx Mice ◽  
Cell Infiltrate ◽  
Immune Cell Infiltrate ◽  
And Oxidative Stress

Patients with Duchenne muscular dystrophy (DMD) have reduced muscle function due to chronic muscle damage, inflammation, oxidative stress, and reduced oxidative capacity. Resveratrol reduces inflammation and oxidative stress, and increases oxidative capacity in other disease models. The purpose of this study was to determine the effects of resveratrol on muscle function, muscle pathology, and oxidative capacity in young mdx mice. For this, 4- to 5-week-old male mdx mice were randomized into control or resveratrol-treated groups and given resveratrol (100 mg/kg body mass) or an equal volume of water by gavage every other day for 8 weeks. Muscle function was assessed pre- and post-treatment. Central nucleation, total immune cell infiltrate, oxidative stress, and oxidative capacity were measured post-treatment. Resveratrol mediated substantial improvements in rotarod performance and in-situ peak tension by 53% and 17%, respectively, and slight improvements in central nucleation and oxidative stress. Resveratrol did not affect total immune cell infiltrate at 12 weeks of age, and had no effect on oxidative capacity. Resveratrol improves muscle function in mdx mice despite small changes in muscle pathology. The likely mechanism is a resveratrol-mediated reduction in immune cell infiltrate at the early stages of this disease, as previously reported by our laboratory.

α-Amyrin attenuates high fructose diet-induced metabolic syndrome in rats

2017 ◽  
Vol 42 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Pankaj Prabhakar ◽  
KH. Reeta ◽  
Subir Kumar Maulik ◽  
Amit Kumar Dinda ◽  
Yogendra Kumar Gupta
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Metabolic Syndrome ◽  
Glucose Tolerance ◽  
Total Cholesterol ◽  
Plasma Glucose ◽  
Once Daily ◽  
Protein Levels ◽  
Insulin Tolerance ◽  
High Fructose

This study investigated the effect of α-amyrin (a pentacyclic triterpene) on high-fructose diet (HFD)-induced metabolic syndrome in rats. Male Wistar rats were randomly distributed into different groups. The control group was fed normal rat chow diet. The HFD group was fed HFD (60%; w/w) for 42 days. Pioglitazone (10 mg/kg, orally, once daily) was used as a standard drug. α-Amyrin was administered in 3 doses (50, 100, and 200 mg/kg, orally, once daily along with HFD). Plasma glucose, total cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL-C) were estimated. Changes in blood pressure, oral glucose tolerance, and insulin tolerance were measured. Hepatic oxidative stress as well as messenger RNA (mRNA) and protein levels of peroxisome proliferator-activated receptor alpha (PPAR-α) were analyzed. A significant increase in systolic blood pressure, plasma glucose, total cholesterol, and plasma triglycerides and a significant decrease in HDL-C were observed in HFD rats as compared with control rats. Glucose tolerance and insulin tolerance were also significantly impaired with HFD. α-Amyrin prevented these changes in a dose–dependent manner. Hepatic oxidative stress as well as micro- and macrovesicular fatty changes in hepatocytes caused by HFD were also attenuated by α-amyrin. α-Amyrin preserved the hepatic mRNA and protein levels of PPAR-α, which was reduced in HFD group. This study thus demonstrates that α-amyrin attenuates HFD-induced metabolic syndrome in rats.

scholarly journals Excitation-contraction coupling alterations in mdx and utrophin/dystrophin double knockout mice: a comparative study

2010 ◽  
Vol 298 (5) ◽  
pp. C1077-C1086 ◽  
Author(s):  
Joana Capote ◽  
Marino DiFranco ◽  
Julio L. Vergara
Keyword(s):  
Action Potentials ◽  
Muscle Pathology ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Wild Type ◽  
Double Knockout ◽  
Contraction Coupling ◽  
Ec Coupling ◽  
Group 2 ◽  
Group 1

The double knockout mouse for utrophin and dystrophin ( utr−/− /mdx) has been proposed to be a better model of Duchenne Muscular Dystrophy (DMD) than the mdx mouse because the former displays more similar muscle pathology to that of the DMD patients. In this paper the properties of action potentials (APs) and Ca2+ transients elicited by single and repetitive stimulation were studied to understand the excitation-contraction (EC) coupling alterations observed in muscle fibers from mdx and utr−/− /mdx mice. Based on the comparison of the AP durations with those of fibers from wild-type (WT) mice, fibers from both mdx and utr−/− /mdx mice could be divided in two groups: fibers with WT-like APs ( group 1) and fibers with significantly longer APs ( group 2). Although the proportion of fibers in group 2 was larger in utr−/− /mdx (36%) than in mdx mice (27%), the Ca2+ release elicited by single stimulation was found to be similarly depressed (32–38%) in utr−/− /mdx and mdx fibers compared with WT counterparts regardless of the fiber's group. Stimulation at 100 Hz revealed that, with the exception of those from utr−/− /mdx mice, group 1 fibers were able to sustain Ca2+ release for longer than group 2 fibers, which displayed an abrupt limitation even at the onset of the train. The differences in behavior between fibers in groups 1 and 2 became almost unnoticeable at 50 Hz stimulation. In general, fibers from utr−/− /mdx mice seem to display more persistent alterations in the EC coupling than those observed in the mdx model.

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