scholarly journals Subcellular distribution of glycogen and decreased tetanic calcium in fatigued single intact mouse muscle fibres

2014 ◽  
Vol 592 (17) ◽  
pp. 3699-3700
Author(s):  
Adrian Hodgson ◽  
Michael McLeod
Keyword(s):  
Subcellular Distribution ◽  
Muscle Fibres ◽  
Intact Mouse ◽  
Mouse Muscle

scholarly journals Subcellular distribution of glycogen and decreased tetanic Ca2+in fatigued single intact mouse muscle fibres

2014 ◽  
Vol 592 (9) ◽  
pp. 2003-2012 ◽  
Author(s):  
Joachim Nielsen ◽  
Arthur J. Cheng ◽  
Niels Ørtenblad ◽  
Håkan Westerblad
Keyword(s):  
Subcellular Distribution ◽  
Muscle Fibres ◽  
Intact Mouse ◽  
Mouse Muscle

scholarly journals TWIST1 and TWIST2 regulate glycogen storage and inflammatory genes in skeletal muscle

2015 ◽  
Vol 224 (3) ◽  
pp. 303-313 ◽  
Author(s):  
Jonathan M Mudry ◽  
Julie Massart ◽  
Ferenc L M Szekeres ◽  
Anna Krook
Keyword(s):  
Skeletal Muscle ◽  
Metabolic Diseases ◽  
Glycogen Synthesis ◽  
C2c12 Cells ◽  
Acid Oxidation ◽  
Diabetic Patients ◽  
Mrna Levels ◽  
Intact Mouse ◽  
Mouse Muscle ◽  
The Impact

TWIST proteins are important for development of embryonic skeletal muscle and play a role in the metabolism of tumor and white adipose tissue. The impact of TWIST on metabolism in skeletal muscle is incompletely studied. Our aim was to assess the impact of TWIST1 and TWIST2 overexpression on glucose and lipid metabolism. In intact mouse muscle, overexpression of Twist reduced total glycogen content without altering glucose uptake. Expression of TWIST1 or TWIST2 reducedPdk4mRNA, while increasing mRNA levels ofIl6,Tnfα, andIl1β. Phosphorylation of AKT was increased and protein abundance of acetyl CoA carboxylase (ACC) was decreased in skeletal muscle overexpressing TWIST1 or TWIST2. Glycogen synthesis and fatty acid oxidation remained stable in C2C12 cells overexpressing TWIST1 or TWIST2. Finally, skeletal muscle mRNA levels remain unaltered inob/obmice, type 2 diabetic patients, or in healthy subjects before and after 3 months of exercise training. Collectively, our results indicate that TWIST1 and TWIST2 are expressed in skeletal muscle. Overexpression of these proteins impacts proteins in metabolic pathways and mRNA level of cytokines. However, skeletal muscle levels of TWIST transcripts are unaltered in metabolic diseases.

scholarly journals Interpolated twitches in fatiguing single mouse muscle fibres: implications for the assessment of central fatigue

2008 ◽  
Vol 586 (11) ◽  
pp. 2799-2805 ◽  
Author(s):  
Nicolas Place ◽  
Takashi Yamada ◽  
Joseph D. Bruton ◽  
Håkan Westerblad
Keyword(s):  
Central Fatigue ◽  
Muscle Fibres ◽  
Mouse Muscle

Ultrastructural localization of dystropin in human muscle by using gold immunolabelling

1990 ◽  
Vol 240 (1297) ◽  
pp. 197-210 ◽  
Keyword(s):  
Plasma Membrane ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Human Muscle ◽  
Muscle Fibres ◽  
Mouse Muscle ◽  
Transverse Tubular System ◽  
Cytoplasmic Face ◽  
Tubular System ◽  
Gold Probe

Immunolabelling with a 5 nm gold probe was used to localize dystrophin at the ultrastructural level in human muscle. The primary antibody was monoclonal, raised against a segment (amino acids 1181-1388) from the rod domain of dystrophin. The antibody (Dy4/6D3) is specific for dystrophin and shows no immunoreactivity with any protein from mdx mouse muscle or from patients with a gene deletion spanning part of the molecule recognized by the antibody (Nicholson et al . 1989 a ; England et al . 1990). Using this antibody, labelling was almost entirely confined to a narrow 75 nm rim at the periphery of the muscle fibres. Histograms of the distance from the gold probe to the cytoplasmic face of the plasma membrane and of the distance between gold probes (nearest neighbour in a plane parallel with the plasma membrane) displayed modes at approximately 15 nm and 120 nm, respectively. The distribution of the probe was the same in longitudinal and transverse sections of the muscle. These observations suggest that the rod portion of the dystrophin mole­cule is normally arranged close to the cytoplasmic face of the plasma membrane and that the molecules form an interconnecting network. Labelling was not associated with the transverse tubular system.

scholarly journals rAAV-related therapy fully rescues myonuclear and myofilament function in X-linked myotubular myopathy

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jacob A. Ross ◽  
Hichem Tasfaout ◽  
Yotam Levy ◽  
Jennifer Morgan ◽  
Belinda S. Cowling ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Contractile Function ◽  
Force Production ◽  
Muscle Disease ◽  
Synthetic Activity ◽  
Muscle Fibres ◽  
Mouse Muscle ◽  
Myotubular Myopathy ◽  
Irregular Spacing ◽  
And Function

Abstract X-linked myotubular myopathy (XLMTM) is a life-threatening skeletal muscle disease caused by mutations in the MTM1 gene. XLMTM fibres display a population of nuclei mispositioned in the centre. In the present study, we aimed to explore whether positioning and overall distribution of nuclei affects cellular organization and contractile function, thereby contributing to muscle weakness in this disease. We also assessed whether gene therapy alters nuclear arrangement and function. We used tissue from human patients and animal models, including XLMTM dogs that had received increasing doses of recombinant AAV8 vector restoring MTM1 expression (rAAV8-cMTM1). We then used single isolated muscle fibres to analyze nuclear organization and contractile function. In addition to the expected mislocalization of nuclei in the centre of muscle fibres, a novel form of nuclear mispositioning was observed: irregular spacing between those located at the fibre periphery, and an overall increased number of nuclei, leading to dramatically smaller and inconsistent myonuclear domains. Nuclear mislocalization was associated with decreases in global nuclear synthetic activity, contractile protein content and intrinsic myofilament force production. A contractile deficit originating at the myofilaments, rather than mechanical interference by centrally positioned nuclei, was supported by experiments in regenerated mouse muscle. Systemic administration of rAAV8-cMTM1 at doses higher than 2.5 × 1013 vg kg−1 allowed a full rescue of all these cellular defects in XLMTM dogs. Altogether, these findings identify previously unrecognized pathological mechanisms in human and animal XLMTM, associated with myonuclear defects and contractile filament function. These defects can be reversed by gene therapy restoring MTM1 expression in dogs with XLMTM.

scholarly journals Acetylcholine receptors in the equatorial region of intrafusal muscle fibres modulate mouse muscle spindle sensitivity

2019 ◽  
Vol 597 (7) ◽  
pp. 1993-2006 ◽  
Author(s):  
Laura Gerwin ◽  
Corinna Haupt ◽  
Katherine A. Wilkinson ◽  
Stephan Kröger
Keyword(s):  
Muscle Spindle ◽  
Acetylcholine Receptors ◽  
Equatorial Region ◽  
Muscle Fibres ◽  
Mouse Muscle ◽  
Intrafusal Muscle

Interactions between intracellular calcium and phosphate in intact mouse muscle during fatigue

2011 ◽  
Vol 111 (2) ◽  
pp. 358-366 ◽  
Author(s):  
D. G. Allen ◽  
E. Clugston ◽  
Y. Petersen ◽  
I. V. Röder ◽  
B. Chapman ◽  
...  
Keyword(s):  
Tibialis Anterior Muscle ◽  
Complete Recovery ◽  
Force Transducer ◽  
Partial Recovery ◽  
Initial Value ◽  
Intact Mouse ◽  
Mouse Muscle ◽  
Intracellular Ca ◽  
Intracellular Phosphate ◽  
Distal Tendon

Fatigue was studied in intact tibialis anterior muscle of anesthetized mice. The distal tendon was detached and connected to a force transducer while blood flow continued normally. The muscle was stimulated with electrodes applied directly to the muscle surface and fatigued by repeated (1 per 4 s), brief (0.4 s), maximal (100-Hz stimulation frequency) tetani. Force declined monotonically to 49 ± 5% of the initial value with a half time of 36 ± 5 s and recovered to 86 ± 4% after 4 min. Intracellular phosphate concentration ([Pi]) was measured by 31P-NMR on perchloric acid extracts of muscles. [Pi] increased during fatigue from 7.6 ± 1.7 to 16.0 ± 1.6 mmol/kg muscle wet wt and returned to control during recovery. Intracellular Ca2+ was measured with cameleons whose plasmids had been transfected in the muscle 2 wk before the experiment. Yellow cameleon 2 was used to measure myoplasmic Ca2+, and D1ER was used to measure sarcoplasmic reticulum (SR) Ca2+. The myoplasmic Ca2+ during tetani declined steadily during the period of fatigue and showed complete recovery over 4 min. The SR Ca2+ also declined monotonically during fatigue and showed a partial recovery with rest. These results show that the initial phase of force decline is accompanied by a rise in [Pi] and a reduction in the tetanic myoplasmic Ca2+. We suggest that both changes contribute to the fatigue. A likely cause of the decline in tetanic myoplasmic Ca2+ is precipitation of CaPi in the SR.

scholarly journals Doublet discharge stimulation increases sarcoplasmic reticulum Ca2+release and improves performance during fatiguing contractions in mouse muscle fibres

2013 ◽  
Vol 591 (15) ◽  
pp. 3739-3748 ◽  
Author(s):  
Arthur J. Cheng ◽  
Nicolas Place ◽  
Joseph D. Bruton ◽  
Hans-Christer Holmberg ◽  
Håkan Westerblad
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Muscle Fibres ◽  
Mouse Muscle ◽  
Fatiguing Contractions

scholarly journals Raising the antioxidant levels within mouse muscle fibres does not affect contraction-induced injury

2006 ◽  
Vol 91 (4) ◽  
pp. 781-789 ◽  
Author(s):  
Erik P. Rader ◽  
Wook Song ◽  
Holly Van Remmen ◽  
Arlan Richardson ◽  
John A. Faulkner
Keyword(s):  
Muscle Fibres ◽  
Mouse Muscle
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