Detection of enterovirus in human skeletal muscle from patients with chronic inflammatory muscle disease or fibromyalgia and healthy subjects

1. The rate of protein synthesis in quadriceps muscle of healthy subjects estimated from the incorporation of l-[1-13C]leucine given by continuous infusion was 1.1%/day. The estimate of protein synthesis from the incorporation of a flooding amount of labelled leucine was 1.8%/day (sd 0.65). The possibility that the higher rate obtained with the flooding technique arose from stimulation of protein synthesis by the large amount of leucine is unlikely. 2. The same rate of protein synthesis (1.7%/day, sd 0.3) was obtained with a flooding amount (0.05 g/kg) of a different amino acid, l-[1-13C]phenylalanine, as was obtained with leucine. 3. Incorporation of l-[1-13C]phenylalanine was not affected by simultaneous injection of leucine (1.7%/day, sd 0.7) or valine (1.6%/day, sd 0.4). 4. Protein synthesis, assessed in a completely different way from the proportion of polyribosomes isolated from the skeletal muscle, was unaltered by the injection of 0.05 g of l-leucine/kg (44.6%, sd 8.5 versus 43.8%, sd 7.7). 5. Good agreement in estimates of protein synthesis was observed in subjects in whom both legs were measured with both l-[1-13C]leucine (mean difference 0.16%/day) and l-[1-13C]phenylalanine (mean difference 0.2%/day).

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WY-14643 and 9-cis-retinoic acid induce IRS-2/PI 3-kinase signalling pathway and increase glucose transport in human skeletal muscle cells: differential effect in myotubes from healthy subjects and Type 2 diabetic patients

Diabetologia ◽

10.1007/s00125-004-1428-1 ◽

2004 ◽

Vol 47 (7) ◽

pp. 1314-1323 ◽

Cited By ~ 13

Author(s):

K. Bouzakri ◽

M. Roques ◽

C. Debard ◽

V. Berbe ◽

J. Rieusset ◽

...

Keyword(s):

Skeletal Muscle ◽

Retinoic Acid ◽

Differential Effect ◽

Healthy Subjects ◽

Human Skeletal Muscle ◽

Diabetic Patients ◽

Type 2 Diabetic Patients ◽

Human Skeletal Muscle Cells ◽

Type 2 Diabetic

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Cardiac troponin-I is not expressed in fetal and healthy or diseased adult human skeletal muscle tissue

Clinical Chemistry ◽

10.1093/clinchem/41.12.1710 ◽

1995 ◽

Vol 41 (12) ◽

pp. 1710-1715 ◽

Cited By ~ 196

Author(s):

G S Bodor ◽

D Porterfield ◽

E M Voss ◽

S Smith ◽

F S Apple

Keyword(s):

Skeletal Muscle ◽

Cardiac Troponin ◽

Human Skeletal Muscle ◽

Troponin I ◽

Tissue Bank ◽

Cardiac Troponin I ◽

Muscle Disease ◽

Adult Skeletal Muscle ◽

Muscle Sample ◽

Creatine Kinase Mb

Abstract Cardiac troponin-I (cTnI) is not found in sera of patients with skeletal muscle disease in the absence of myocardial injury. It is not known, however, whether trace amounts of cTnI are expressed in regenerating human skeletal muscle, as has been observed with creatine kinase MB. Using immunohistochemical and biochemical techniques, we investigated cTnI expression in various human muscle tissues: human heart tissue (n = 5), normal adult skeletal muscle (n = 3), and fetal heart (n = 3) and skeletal muscle (n = 3) obtained, respectively, during heart transplant, from autopsy, or from a tissue bank. Specimens from diagnostic tissue biopsies were used as diseased skeletal muscle: polymyositis (PM), n = 13; Duchenne muscular dystrophy (DMD), n = 6. Frozen sections 8 microns thick were stained immunohistochemically for either cTnI or TnI (cardiac or skeletal) by using monoclonal antibodies (MAb) 2B1.9 (cTnI specific) or 3C5.10 (reactive with all TnI isoforms), respectively. cTnI was measured in tissue homogenates by an immunofluorometric assay. Cardiac muscle was stained by both MAbs. Normal fetal and adult skeletal muscle, and samples from all of the PM and DMD patients, stained only with the nonspecific MAb (3C5.10), confirming the sole presence of skeletal TnI. No cTnI was detectable by immunoassay in any skeletal muscle sample. We conclude that cTnI is not expressed in human skeletal muscle during development or during regenerative muscle disease processes such as PM or DMD.

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Expression profiles of muscle disease-associated genes and their isoforms during differentiation of cultured human skeletal muscle cells

BMC Musculoskeletal Disorders ◽

10.1186/1471-2474-13-262 ◽

2012 ◽

Vol 13 (1) ◽

Cited By ~ 8

Author(s):

Saba Abdul-Hussein ◽

Peter F M van der Ven ◽

Homa Tajsharghi

Keyword(s):

Skeletal Muscle ◽

Human Skeletal Muscle ◽

Expression Profiles ◽

Muscle Cells ◽

Muscle Disease ◽

Skeletal Muscle Cells ◽

Human Skeletal Muscle Cells ◽

Disease Associated Genes

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Exercise mimetics and JAK inhibition attenuate IFN-γ–induced wasting in engineered human skeletal muscle

Science Advances ◽

10.1126/sciadv.abd9502 ◽

2021 ◽

Vol 7 (4) ◽

pp. eabd9502 ◽

Cited By ~ 1

Author(s):

Zhaowei Chen ◽

Binjie Li ◽

Ren-Zhi Zhan ◽

Lingjun Rao ◽

Nenad Bursac

Keyword(s):

Skeletal Muscle ◽

Human Skeletal Muscle ◽

Inflammatory Diseases ◽

Interferon Γ ◽

Janus Kinase ◽

Muscle Disease ◽

Ifn Γ ◽

Anti Inflammatory ◽

Underlying Mechanisms

Chronic inflammatory diseases often lead to muscle wasting and contractile deficit. While exercise can have anti-inflammatory effects, the underlying mechanisms remain unclear. Here, we used an in vitro tissue-engineered model of human skeletal muscle (“myobundle”) to study effects of exercise-mimetic electrical stimulation (E-stim) on interferon-γ (IFN-γ)–induced muscle weakness. Chronic IFN-γ treatment of myobundles derived from multiple donors induced myofiber atrophy and contractile loss. E-stim altered the myobundle secretome, induced myofiber hypertrophy, and attenuated the IFN-γ–induced myobundle wasting and weakness, in part by down-regulating JAK (Janus kinase)/STAT1 (signal transducer and activator of transcription 1) signaling pathway amplified by IFN-γ. JAK/STAT inhibitors fully prevented IFN-γ–induced myopathy, confirming the critical roles of STAT1 activation in proinflammatory action of IFN-γ. Our results reveal a previously unknown mechanism of the cell-autonomous anti-inflammatory effects of muscle exercise and establish the utility of human myobundle platform for studies of inflammatory muscle disease and therapy.

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Contribution of Nonesterified Fatty Acids to Mitogen-Activated Protein Kinase Activation in Human Skeletal Muscle During Endurance Exercise

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.23.3.201 ◽

2013 ◽

Vol 23 (3) ◽

pp. 201-209 ◽

Cited By ~ 8

Author(s):

Hermann Zbinden-Foncea ◽

Luc J. C. van Loon ◽

Jean-Marc Raymackers ◽

Marc Francaux ◽

Louise Deldicque

Keyword(s):

Skeletal Muscle ◽

Fatty Acids ◽

Endurance Exercise ◽

Healthy Subjects ◽

Human Skeletal Muscle ◽

Mitogen Activated Protein Kinase ◽

Plasma Nefa ◽

Nonesterified Fatty Acids ◽

Patients With Diabetes ◽

Mitogen Activated Protein

Mitogen-activated protein kinase (MAPK) pathways are activated in skeletal muscle during endurance exercise, but the upstream molecular events are incompletely resolved. As an increase in plasma nonesterified fatty acids (NEFA) is a common feature of long-lasting exercise, the authors tested the hypothesis that NEFA contribute to the activation of MAPK during endurance exercise. Acipimox was used before and during endurance exercise to prevent the elevation of plasma NEFA levels in healthy subjects and patients with diabetes. In 2 separate studies, healthy subjects cycled for 2 hr and patients with diabetes for 1 hr at 50% Wmax. In control conditions, plasma NEFA concentrations increased from 0.35 to 0.90 mM during exercise in healthy subjects and from 0.55 to 0.70 mM in patients with diabetes (p < .05). Phosphorylation states of extracellularly regulated kinase 1 and 2 (ERK1/2), p38, and c-Jun NH2-terminal kinases (JNK) were significantly increased after exercise in the vastus lateralis in both groups. Acipimox blocked the increase in plasma NEFA concentrations and almost completely repressed any rise in ERK1/2 and p38 but not in JNK. In conclusion, the data support a role for plasma NEFA in the activation of p38 and ERK1/2 in skeletal-muscle tissue of healthy and diabetic subjects during endurance exercise. Further investigation will be required to determine the molecular link between NEFA and MAPK activation during exercise in human skeletal muscle.

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