Compartment Syndrome: Evaluation of Skeletal Muscle Ischemia and Physiologic Biomarkers in Controlled Conditions Within Ex Vivo Isolated Muscle Bundles

2020 ◽  
Vol 34 (10) ◽  
pp. 518-523 ◽  
Author(s):  
Lauren M. Tatman ◽  
Weston J. Upchurch ◽  
Natalie Scholz ◽  
Emily Wagstrom ◽  
Lauren L. Smith ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Compartment Syndrome ◽  
Ex Vivo ◽  
Muscle Ischemia ◽  
Controlled Conditions

scholarly journals Global Deletion of 11β-HSD1 Prevents Muscle Wasting Associated with Glucocorticoid Therapy in Polyarthritis

2021 ◽  
Vol 22 (15) ◽  
pp. 7828
Author(s):  
Justine M. Webster ◽  
Michael S. Sagmeister ◽  
Chloe G. Fenton ◽  
Alex P. Seabright ◽  
Yu-Chiang Lai ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Skeletal Muscle ◽  
Chronic Inflammation ◽  
Muscle Atrophy ◽  
Muscle Wasting ◽  
Ex Vivo ◽  
Glucocorticoid Therapy ◽  
Knock Out ◽  
Fiber Size ◽  
Anti Inflammatory

Glucocorticoids provide indispensable anti-inflammatory therapies. However, metabolic adverse effects including muscle wasting restrict their use. The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) modulates peripheral glucocorticoid responses through pre-receptor metabolism. This study investigates how 11β-HSD1 influences skeletal muscle responses to glucocorticoid therapy for chronic inflammation. We assessed human skeletal muscle biopsies from patients with rheumatoid arthritis and osteoarthritis for 11β-HSD1 activity ex vivo. Using the TNF-α-transgenic mouse model (TNF-tg) of chronic inflammation, we examined the effects of corticosterone treatment and 11β-HSD1 global knock-out (11βKO) on skeletal muscle, measuring anti-inflammatory gene expression, muscle weights, fiber size distribution, and catabolic pathways. Muscle 11β-HSD1 activity was elevated in patients with rheumatoid arthritis and correlated with inflammation markers. In murine skeletal muscle, glucocorticoid administration suppressed IL6 expression in TNF-tg mice but not in TNF-tg11βKO mice. TNF-tg mice exhibited reductions in muscle weight and fiber size with glucocorticoid therapy. In contrast, TNF-tg11βKO mice were protected against glucocorticoid-induced muscle atrophy. Glucocorticoid-mediated activation of catabolic mediators (FoxO1, Trim63) was also diminished in TNF-tg11βKO compared to TNF-tg mice. In summary, 11β-HSD1 knock-out prevents muscle atrophy associated with glucocorticoid therapy in a model of chronic inflammation. Targeting 11β-HSD1 may offer a strategy to refine the safety of glucocorticoids.

scholarly journals Consequences of SUR2[A478V] Mutation in Skeletal Muscle of Murine Model of Cantu Syndrome

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1791
Author(s):  
Rosa Scala ◽  
Fatima Maqoud ◽  
Nicola Zizzo ◽  
Giuseppe Passantino ◽  
Antonietta Mele ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Katp Channel ◽  
Ex Vivo ◽  
Channel Modulation ◽  
Flexor Digitorum Brevis ◽  
Inflammatory Edema ◽  
Flexor Digitorum ◽  
Channel Currents

(1) Background: Cantu syndrome (CS) arises from gain-of-function (GOF) mutations in the ABCC9 and KCNJ8 genes, which encode ATP-sensitive K+ (KATP) channel subunits SUR2 and Kir6.1, respectively. Most CS patients have mutations in SUR2, the major component of skeletal muscle KATP, but the consequences of SUR2 GOF in skeletal muscle are unknown. (2) Methods: We performed in vivo and ex vivo characterization of skeletal muscle in heterozygous SUR2[A478V] (SUR2wt/AV) and homozygous SUR2[A478V] (SUR2AV/AV) CS mice. (3) Results: In SUR2wt/AV and SUR2AV/AV mice, forelimb strength and diaphragm amplitude movement were reduced; muscle echodensity was enhanced. KATP channel currents recorded in Flexor digitorum brevis fibers showed reduced MgATP-sensitivity in SUR2wt/AV, dramatically so in SUR2AV/AV mice; IC50 for MgATP inhibition of KATP currents were 1.9 ± 0.5 × 10−5 M in SUR2wt/AV and 8.6 ± 0.4 × 10−6 M in WT mice and was not measurable in SUR2AV/AV. A slight rightward shift of sensitivity to inhibition by glibenclamide was detected in SUR2AV/AV mice. Histopathological and qPCR analysis revealed atrophy of soleus and tibialis anterior muscles and up-regulation of atrogin-1 and MuRF1 mRNA in CS mice. (4) Conclusions: SUR2[A478V] “knock-in” mutation in mice impairs KATP channel modulation by MgATP, markedly so in SUR2AV/AV, with atrophy and non-inflammatory edema in different skeletal muscle phenotypes.

Aging does not alter the mechanosensitivity of the p38, p70S6k, and JNK2 signaling pathways in skeletal muscle

2005 ◽  
Vol 98 (4) ◽  
pp. 1562-1566 ◽  
Author(s):  
Troy A. Hornberger ◽  
R. D. Mateja ◽  
E. R. Chin ◽  
J. L. Andrews ◽  
K. A. Esser
Keyword(s):  
Skeletal Muscle ◽  
Signaling Pathways ◽  
Ex Vivo ◽  
Mechanical Stimuli ◽  
S6 Kinase ◽  
Diminished Capacity ◽  
Ribosomal S6 Kinase ◽  
Passive Stretch ◽  
Old Mice ◽  
Dependent Mechanism

The capacity for skeletal muscle to recover its mass following periods of unloading (regrowth) has been reported to decline with age. Although the mechanisms responsible for the impaired regrowth are not known, it has been suggested that aged muscles have a diminished capacity to sense and subsequently respond to a given amount of mechanical stimuli (mechanosensitivity). To test this hypothesis, extensor digitorum longus muscles from young (2–3 mo) and old (26–27 mo) mice were subjected to intermittent 15% passive stretch (ex vivo) as a source of mechanical stimulation and analyzed for alterations in the phosphorylation of stress-activated protein kinase (p38), ribosomal S6 kinase (p70S6k), and the p54 jun N-terminal kinase (JNK2). The results indicated that the average magnitude of specific tension (mechanical stimuli) induced by 15% stretch was similar in muscles from young and old mice. Young and old muscles also revealed similar increases in the magnitude of mechanically induced p38, p70S6k (threonine/serine 421/424 and threonine 389), and JNK2 phosphorylation. In addition, coincubation experiments demonstrated that the release of locally acting growth factors was not sufficient for the induction of JNK2 phosphorylation, suggesting that JNK2 was activated by a mechanical rather than a mechanical/growth factor-dependent mechanism. Taken together, the results of this study demonstrate that aging does not alter the mechanosensitivity of the p38, p70S6k, and JNK2 signaling pathways in skeletal muscle.

Ex vivo gene transfer to mature skeletal muscle by using adenovirus helper cells

2004 ◽  
Vol 6 (2) ◽  
pp. 155-165
Author(s):  
Shigemi Kimura ◽  
Makoto Ikezawa ◽  
Baohong Cao ◽  
Yasunari Kanda ◽  
Ryan Pruchnic ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Gene Transfer ◽  
Ex Vivo ◽  
Helper Cells ◽  
Ex Vivo Gene Transfer

Neutrophils as mediators of human skeletal muscle ischemia-reperfusion syndrome

1992 ◽  
Vol 23 (6) ◽  
pp. 627-634 ◽  
Author(s):  
Lucia Formigli ◽  
Lola Domenici Lombardo ◽  
Chiara Adembri ◽  
Sandra Brunelleschi ◽  
Enrico Ferrari ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Ischemia Reperfusion ◽  
Muscle Ischemia

Glucose uptake during contraction in isolated skeletal muscles from neuronal nitric oxide synthase μ knockout mice

2015 ◽  
Vol 118 (9) ◽  
pp. 1113-1121 ◽  
Author(s):  
Yet Hoi Hong ◽  
Tony Frugier ◽  
Xinmei Zhang ◽  
Robyn M. Murphy ◽  
Gordon S. Lynch ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Nitric Oxide Synthase ◽  
Glucose Uptake ◽  
Ex Vivo ◽  
Organ Bath ◽  
Skeletal Muscle Glucose Uptake ◽  
Nos Inhibitor ◽  
Amp Activated Protein Kinase ◽  
Oxide Synthase

Inhibition of nitric oxide synthase (NOS) significantly attenuates the increase in skeletal muscle glucose uptake during contraction/exercise, and a greater attenuation is observed in individuals with Type 2 diabetes compared with healthy individuals. Therefore, NO appears to play an important role in mediating muscle glucose uptake during contraction. In this study, we investigated the involvement of neuronal NOSμ (nNOSμ), the main NOS isoform activated during contraction, on skeletal muscle glucose uptake during ex vivo contraction. Extensor digitorum longus muscles were isolated from nNOSμ−/−and nNOSμ+/+mice. Muscles were contracted ex vivo in a temperature-controlled (30°C) organ bath with or without the presence of the NOS inhibitor NG-monomethyl-l-arginine (L-NMMA) and the NOS substrate L-arginine. Glucose uptake was determined by radioactive tracers. Skeletal muscle glucose uptake increased approximately fourfold during contraction in muscles from both nNOSμ−/−and nNOSμ+/+mice. L-NMMA significantly attenuated the increase in muscle glucose uptake during contraction in both genotypes. This attenuation was reversed by L-arginine, suggesting that L-NMMA attenuated the increase in muscle glucose uptake during contraction by inhibiting NOS and not via a nonspecific effect of the inhibitor. Low levels of NOS activity (∼4%) were detected in muscles from nNOSμ−/−mice, and there was no evidence of compensation from other NOS isoform or AMP-activated protein kinase which is also involved in mediating muscle glucose uptake during contraction. These results indicate that NO regulates skeletal muscle glucose uptake during ex vivo contraction independently of nNOSμ.

Microcirculatory Dysfunction in the Pathophysiology of Skeletal Muscle Ischemia

2003 ◽  
Author(s):  
Walter Durán ◽  
Mauricio Bori_ ◽  
Peter Pappas ◽  
Robert HobsonII
Keyword(s):  
Skeletal Muscle ◽  
Microcirculatory Dysfunction ◽  
Muscle Ischemia

scholarly journals Association between vitamin D deficiency and exercise capacity in patients with CKD, a cross-sectional analysis

2020 ◽  
Author(s):  
Emma L Watson ◽  
Thomas J Wilkinson ◽  
Tom F O’Sullivan ◽  
Luke A Baker ◽  
Douglas W Gould ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Exercise Capacity ◽  
Muscle Mass ◽  
Ex Vivo ◽  
Muscle Size ◽  
Cross Sectional ◽  
Cross Sectional Analysis ◽  
Sectional Analysis

AbstractEvidence is growing for a role of vitamin D in regulating skeletal muscle mass, strength and functional capacity. Given the role the kidneys play in activating total vitamin D, and the high prevalence of vitamin D deficiency in Chronic Kidney Disease (CKD), it is possible that deficiency contributes to the low levels of physical function and muscle mass in these patients. This is a secondary cross-sectional analysis of previously published interventional study, with ex vivo follow up work. 34 CKD patients at stages G3b-5 (eGFR 25.5 ± 8.3ml/min/1.73m2; age 61 ± 12 years) were recruited, with a sub-group (n=20) also donating a muscle biopsy. Vitamin D and associated metabolites were analysed in plasma by liquid chromatography tandem-mass spectroscopy and correlated to a range of physiological tests of muscle size, function, exercise capacity and body composition. The effects of 1α,25(OH)2D3 supplementation on myogenesis and myotube size was investigated in primary skeletal muscle cells from vitamin D deficient donors. In vivo, there was no association between total or active vitamin D and muscle size or strength, but a significant correlation with was seen with the total form. Ex vivo, 1α,25(OH)2D3 supplementation reduced IL-6 mRNA expression, but had no effect upon proliferation, differentiation or myotube diameter. This early preliminary work suggests that vitamin D deficiency is not a prominent factor driving the loss of muscle mass in CKD, but may play a role in reduced exercise capacity.

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.

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