Aquaporin‐4 deficiency in skeletal muscle and brain of dystrophic mdx mice

2001 ◽  
Vol 15 (1) ◽  
pp. 90-98 ◽  
Author(s):  
ANTONIO FRIGERI ◽  
GRAZIA PAOLA NICCHIA ◽  
BEATRICE NICO ◽  
FABIO QUONDAMATTEO ◽  
RAINER HERKEN ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Aquaporin 4 ◽  
Mdx Mice

scholarly journals Autophagy in the heart is enhanced and independent of disease progression in mus musculus dystrophinopathy models

2019 ◽  
Vol 8 ◽  
pp. 204800401987958
Author(s):  
HR Spaulding ◽  
C Ballmann ◽  
JC Quindry ◽  
MB Hudson ◽  
JT Selsby
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Disease Progression ◽  
Gene Mutations ◽  
Dystrophin Gene ◽  
Mdx Mice ◽  
Dystrophin Deficiency ◽  
Muscle Wasting Disease ◽  
Dystrophin Protein

Background Duchenne muscular dystrophy is a muscle wasting disease caused by dystrophin gene mutations resulting in dysfunctional dystrophin protein. Autophagy, a proteolytic process, is impaired in dystrophic skeletal muscle though little is known about the effect of dystrophin deficiency on autophagy in cardiac muscle. We hypothesized that with disease progression autophagy would become increasingly dysfunctional based upon indirect autophagic markers. Methods Markers of autophagy were measured by western blot in 7-week-old and 17-month-old control (C57) and dystrophic (mdx) hearts. Results Counter to our hypothesis, markers of autophagy were similar between groups. Given these surprising results, two independent experiments were conducted using 14-month-old mdx mice or 10-month-old mdx/Utrn± mice, a more severe model of Duchenne muscular dystrophy. Data from these animals suggest increased autophagosome degradation. Conclusion Together these data suggest that autophagy is not impaired in the dystrophic myocardium as it is in dystrophic skeletal muscle and that disease progression and related injury is independent of autophagic dysfunction.

scholarly journals Early metabolic changes measured by 1H MRS in healthy and dystrophic muscle after injury

2012 ◽  
Vol 113 (5) ◽  
pp. 808-816 ◽  
Author(s):  
Su Xu ◽  
Stephen J. P. Pratt ◽  
Espen E. Spangenburg ◽  
Richard M. Lovering
Keyword(s):  
Skeletal Muscle ◽  
Muscle Injury ◽  
Tibialis Anterior Muscle ◽  
Metabolic Changes ◽  
Mdx Mice ◽  
Resonance Spectroscopy ◽  
Dystrophic Muscle ◽  
1H Mrs ◽  
Skeletal Muscle Injury

Skeletal muscle injury is often assessed by clinical findings (history, pain, tenderness, strength loss), by imaging, or by invasive techniques. The purpose of this work was to determine if in vivo proton magnetic resonance spectroscopy (1H MRS) could reveal metabolic changes in murine skeletal muscle after contraction-induced injury. We compared findings in the tibialis anterior muscle from both healthy wild-type (WT) muscles (C57BL/10 mice) and dystrophic ( mdx mice) muscles (an animal model for human Duchenne muscular dystrophy) before and after contraction-induced injury. A mild in vivo eccentric injury protocol was used due to the high susceptibility of mdx muscles to injury. As expected, mdx mice sustained a greater loss of force (81%) after injury compared with WT (42%). In the uninjured muscles, choline (Cho) levels were 47% lower in the mdx muscles compared with WT muscles. In mdx mice, taurine levels decreased 17%, and Cho levels increased 25% in injured muscles compared with uninjured mdx muscles. Intramyocellular lipids and total muscle lipid levels increased significantly after injury but only in WT. The increase in lipid was confirmed using a permeable lipophilic fluorescence dye. In summary, loss of torque after injury was associated with alterations in muscle metabolite levels that may contribute to the overall injury response in mdx mice. These results show that it is possible to obtain meaningful in vivo 1H MRS regarding skeletal muscle injury.

scholarly journals The IRE1/XBP1 signaling axis promotes skeletal muscle regeneration through a cell non-autonomous mechanism

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Anirban Roy ◽  
Meiricris Tomaz da Silva ◽  
Raksha Bhat ◽  
Kyle R Bohnert ◽  
Takao Iwawaki ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cells ◽  
Muscle Regeneration ◽  
Ex Vivo ◽  
Skeletal Muscle Regeneration ◽  
Mdx Mice ◽  
Major Mechanism ◽  
Downstream Target ◽  
A Cell ◽  
The Unfolded Protein Response

Skeletal muscle regeneration is regulated by coordinated activation of multiple signaling pathways activated in both injured myofibers and satellite cells. The unfolded protein response (UPR) is a major mechanism that detects and alleviates protein-folding stresses in ER. However, the role of individual arms of the UPR in skeletal muscle regeneration remain less understood. In the present study, we demonstrate that IRE1α (also known as ERN1) and its downstream target, XBP1, are activated in skeletal muscle of mice upon injury. Myofiber-specific ablation of IRE1 or XBP1 in mice diminishes skeletal muscle regeneration that is accompanied with reduced number of satellite cells and their fusion to injured myofibers. Ex vivo cultures of myofiber explants demonstrate that ablation of IRE1α reduces the proliferative capacity of myofiber-associated satellite cells. Myofiber-specific deletion of IRE1α dampens Notch signaling and canonical NF-kB pathway in skeletal muscle of mice. Our results also demonstrate that targeted ablation of IRE1α reduces skeletal muscle regeneration in the mdx mice, a model of Duchenne muscular dystrophy. Collectively, our results reveal that the IRE1α-mediated signaling promotes muscle regeneration through augmenting the proliferation of satellite cells in a cell non-autonomous manner.

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

1998 ◽  
Vol 95 (1) ◽  
pp. 83 ◽  
Author(s):  
Anne McARDLE ◽  
Timothy R. HELLIWELL ◽  
Geoffrey J. BECKETT ◽  
Mariana CATAPANO ◽  
Anthony DAVIS ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mdx Mice ◽  
Muscle Necrosis

scholarly journals Atrogin1-induced loss of aquaporin 4 in myocytes leads to skeletal muscle atrophy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Seok Won Chung ◽  
Ja-Yeon Kim ◽  
Jong Pil Yoon ◽  
Dong Won Suh ◽  
Woo Jin Yeo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Aquaporin 4 ◽  
Skeletal Muscle Atrophy

scholarly journals ProNGF/p75NTR Axis Drives Fiber Type Specification by Inducing the Fast-Glycolytic Phenotype in Mouse Skeletal Muscle Cells

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2232
Author(s):  
Valentina Pallottini ◽  
Mayra Colardo ◽  
Claudia Tonini ◽  
Noemi Martella ◽  
Georgios Strimpakos ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Myogenic Differentiation ◽  
Fiber Type ◽  
Pcr Analysis ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Muscle Physiology

Despite its undisputable role in the homeostatic regulation of the nervous system, the nerve growth factor (NGF) also governs the relevant cellular processes in other tissues and organs. In this study, we aimed at assessing the expression and the putative involvement of NGF signaling in skeletal muscle physiology. To reach this objective, we employed satellite cell-derived myoblasts as an in vitro culture model. In vivo experiments were performed on Tibialis anterior from wild-type mice and an mdx mouse model of Duchenne muscular dystrophy. Targets of interest were mainly assessed by means of morphological, Western blot and qRT-PCR analysis. The results show that proNGF is involved in myogenic differentiation. Importantly, the proNGF/p75NTR pathway orchestrates a slow-to-fast fiber type transition by counteracting the expression of slow myosin heavy chain and that of oxidative markers. Concurrently, proNGF/p75NTR activation facilitates the induction of fast myosin heavy chain and of fast/glycolytic markers. Furthermore, we also provided evidence that the oxidative metabolism is impaired in mdx mice, and that these alterations are paralleled by a prominent buildup of proNGF and p75NTR. These findings underline that the proNGF/p75NTR pathway may play a crucial role in fiber type determination and suggest its prospective modulation as an innovative therapeutic approach to counteract muscle disorders.

scholarly journals Overexpression of Galgt2 in skeletal muscle prevents injury resulting from eccentric contractions in both mdx and wild-type mice

2009 ◽  
Vol 296 (3) ◽  
pp. C476-C488 ◽  
Author(s):  
Paul T. Martin ◽  
Rui Xu ◽  
Louise R. Rodino-Klapac ◽  
Elaine Oglesbay ◽  
Marybeth Camboni ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscular Dystrophy ◽  
Transgenic Mice ◽  
Skeletal Muscles ◽  
Eccentric Contractions ◽  
Cytotoxic T Cell ◽  
Muscle Pathology ◽  
Mdx Mice ◽  
Specific Force ◽  
Wild Type

The cytotoxic T cell (CT) GalNAc transferase, or Galgt2, is a UDP-GalNAc:β1,4- N-acetylgalactosaminyltransferase that is localized to the neuromuscular synapse in adult skeletal muscle, where it creates the synaptic CT carbohydrate antigen {GalNAcβ1,4[NeuAc(orGc)α2, 3]Galβ1,4GlcNAcβ-}. Overexpression of Galgt2 in the skeletal muscles of transgenic mice inhibits the development of muscular dystrophy in mdx mice, a model for Duchenne muscular dystrophy. Here, we provide physiological evidence as to how Galgt2 may inhibit the development of muscle pathology in mdx animals. Both Galgt2 transgenic wild-type and mdx skeletal muscles showed a marked improvement in normalized isometric force during repetitive eccentric contractions relative to nontransgenic littermates, even using a paradigm where nontransgenic muscles had force reductions of 95% or more. Muscles from Galgt2 transgenic mice, however, showed a significant decrement in normalized specific force and in hindlimb and forelimb grip strength at some ages. Overexpression of Galgt2 in muscles of young adult mdx mice, where Galgt2 has no effect on muscle size, also caused a significant decrease in force drop during eccentric contractions and increased normalized specific force. A comparison of Galgt2 and microdystrophin overexpression using a therapeutically relevant intravascular gene delivery protocol showed Galgt2 was as effective as microdystrophin at preventing loss of force during eccentric contractions. These experiments provide a mechanism to explain why Galgt2 overexpression inhibits muscular dystrophy in mdx muscles. That overexpression also prevents loss of force in nondystrophic muscles suggests that Galgt2 is a therapeutic target with broad potential applications.

Muscle-specific overexpression of IGF-I improves E-C coupling in skeletal muscle fibers from dystrophic mdx mice

2008 ◽  
Vol 294 (1) ◽  
pp. C161-C168 ◽  
Author(s):  
Jonathan D. Schertzer ◽  
Chris van der Poel ◽  
Thea Shavlakadze ◽  
Miranda D. Grounds ◽  
Gordon S. Lynch
Keyword(s):  
Skeletal Muscle ◽  
Growth Factor ◽  
Muscle Fibers ◽  
Transcript Level ◽  
Direct Result ◽  
Mdx Mice ◽  
Contractile Apparatus ◽  
Dystrophic Muscle ◽  
Insulin Growth Factor ◽  
Igf I

Duchenne muscular dystrophy (DMD) is a lethal X-linked disease caused by the absence of functional dystrophin. Abnormal excitation-contraction (E-C) coupling has been reported in dystrophic muscle fibers from mdx mice, and alterations in E-C coupling components may occur as a direct result of dystrophin deficiency. We hypothesized that muscle-specific overexpression of insulin-growth factor-1 (IGF-I) would reduce E-C coupling failure in mdx muscle. Mechanically skinned extensor digitorum longus muscle fibers from mdx mice displayed a faster decline in depolarization-induced force responses (DIFR); however, there were no differences in sarcoplasmic reticulum (SR)-mediated Ca2+ resequestration or in the properties of the contractile apparatus when compared with nondystrophic controls. The rate of DIFR decline was restored to control levels in fibers from transgenic mdx mice that overexpressed IGF-I in skeletal muscle ( mdx/IGF-I mice). Dystrophic muscles have a lower transcript level of a specific dihydropyridine receptor (DHPR) isoform, and IGF-I-mediated changes in E-C coupling were associated with increased transcript levels of specific DHPR isoforms involved in Ca2+ regulation. Importantly, IGF-I overexpression also increased the sensitivity of the contractile apparatus to Ca2+. The results demonstrate that IGF-I can ameliorate fundamental aspects of E-C coupling failure in dystrophic muscle fibers and that these effects are important for the improvements in cellular function induced by this growth factor.

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