The role of phosphorylcreatine and creatine in the regulation of mitochondrial respiration in human skeletal muscle

2001 ◽  
Vol 537 (3) ◽  
pp. 971-978 ◽  
Author(s):  
B Walsh ◽  
M Tonkonogi ◽  
K Soderlund ◽  
E Hultman ◽  
V Saks ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Respiration ◽  
Human Skeletal Muscle

Does impaired mitochondrial function affect insulin signaling and action in cultured human skeletal muscle cells?

2008 ◽  
Vol 294 (1) ◽  
pp. E97-E102 ◽  
Author(s):  
Audrey E. Brown ◽  
Matthias Elstner ◽  
Stephen J. Yeaman ◽  
Douglass M. Turnbull ◽  
Mark Walker
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Insulin Signaling ◽  
Mitochondrial Respiration ◽  
Respiratory Function ◽  
Insulin Action ◽  
Human Skeletal Muscle ◽  
Human Skeletal Muscle Cells ◽  
Basal Glucose Uptake

Insulin-resistant type 2 diabetic patients have been reported to have impaired skeletal muscle mitochondrial respiratory function. A key question is whether decreased mitochondrial respiration contributes directly to the decreased insulin action. To address this, a model of impaired cellular respiratory function was established by incubating human skeletal muscle cell cultures with the mitochondrial inhibitor sodium azide and examining the effects on insulin action. Incubation of human skeletal muscle cells with 50 and 75 μM azide resulted in 48 ± 3% and 56 ± 1% decreases, respectively, in respiration compared with untreated cells mimicking the level of impairment seen in type 2 diabetes. Under conditions of decreased respiratory chain function, insulin-independent (basal) glucose uptake was significantly increased. Basal glucose uptake was 325 ± 39 pmol/min/mg (mean ± SE) in untreated cells. This increased to 669 ± 69 and 823 ± 83 pmol/min/mg in cells treated with 50 and 75 μM azide, respectively (vs. untreated, both P < 0.0001). Azide treatment was also accompanied by an increase in basal glycogen synthesis and phosphorylation of AMP-activated protein kinase. However, there was no decrease in glucose uptake following insulin exposure, and insulin-stimulated phosphorylation of Akt was normal under these conditions. GLUT1 mRNA expression remained unchanged, whereas GLUT4 mRNA expression increased following azide treatment. In conclusion, under conditions of impaired mitochondrial respiration there was no evidence of impaired insulin signaling or glucose uptake following insulin exposure in this model system.

The role of agrin during the maturation of human skeletal muscle fibres

2006 ◽  
Vol 99 (2-3) ◽  
pp. 1
Author(s):  
Fabio Ruzzier ◽  
Elena Bandi ◽  
Mihaela Jurdana ◽  
Paola Lorenzon ◽  
Marina Sciancalepore
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Muscle Fibres ◽  
Skeletal Muscle Fibres

scholarly journals FGF-2–dependent signaling activated in aged human skeletal muscle promotes intramuscular adipogenesis

2021 ◽  
Vol 118 (37) ◽  
pp. e2021013118 ◽  
Author(s):  
Sebastian Mathes ◽  
Alexandra Fahrner ◽  
Umesh Ghoshdastider ◽  
Hannes A. Rüdiger ◽  
Michael Leunig ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Transcriptional Activation ◽  
Human Skeletal Muscle ◽  
Muscle Growth ◽  
Muscle Cells ◽  
Adeno Associated Virus ◽  
Adult Skeletal Muscle

Aged skeletal muscle is markedly affected by fatty muscle infiltration, and strategies to reduce the occurrence of intramuscular adipocytes are urgently needed. Here, we show that fibroblast growth factor-2 (FGF-2) not only stimulates muscle growth but also promotes intramuscular adipogenesis. Using multiple screening assays upstream and downstream of microRNA (miR)-29a signaling, we located the secreted protein and adipogenic inhibitor SPARC to an FGF-2 signaling pathway that is conserved between skeletal muscle cells from mice and humans and that is activated in skeletal muscle of aged mice and humans. FGF-2 induces the miR-29a/SPARC axis through transcriptional activation of FRA-1, which binds and activates an evolutionary conserved AP-1 site element proximal in the miR-29a promoter. Genetic deletions in muscle cells and adeno-associated virus–mediated overexpression of FGF-2 or SPARC in mouse skeletal muscle revealed that this axis regulates differentiation of fibro/adipogenic progenitors in vitro and intramuscular adipose tissue (IMAT) formation in vivo. Skeletal muscle from human donors aged >75 y versus <55 y showed activation of FGF-2–dependent signaling and increased IMAT. Thus, our data highlights a disparate role of FGF-2 in adult skeletal muscle and reveals a pathway to combat fat accumulation in aged human skeletal muscle.

scholarly journals Mitochondrial respiration variability and simulations in human skeletal muscle: The Gene SMART study

2020 ◽  
Vol 34 (2) ◽  
pp. 2978-2986 ◽  
Author(s):  
Macsue Jacques ◽  
Jujiao Kuang ◽  
David J. Bishop ◽  
Xu Yan ◽  
Javier Alvarez‐Romero ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Respiration ◽  
Human Skeletal Muscle ◽  
Smart Study

scholarly journals The vitamin D receptor regulates mitochondrial function in C2C12 myoblasts

2020 ◽  
Vol 318 (3) ◽  
pp. C536-C541 ◽  
Author(s):  
Stephen P. Ashcroft ◽  
Joseph J. Bass ◽  
Abid A. Kazi ◽  
Philip J. Atherton ◽  
Andrew Philp
Keyword(s):  
Skeletal Muscle ◽  
Vitamin D ◽  
Protein Content ◽  
Vitamin D Receptor ◽  
Mitochondrial Function ◽  
Mitochondrial Respiration ◽  
Oxidative Capacity ◽  
C2c12 Myoblasts

Vitamin D deficiency has been linked to a reduction in skeletal muscle function and oxidative capacity; however, the mechanistic bases of these impairments are poorly understood. The biological actions of vitamin D are carried out via the binding of 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) to the vitamin D receptor (VDR). Recent evidence has linked 1α,25(OH)2D3 to the regulation of skeletal muscle mitochondrial function in vitro; however, little is known with regard to the role of the VDR in this process. To examine the regulatory role of the VDR in skeletal muscle mitochondrial function, we used lentivirus-mediated shRNA silencing of the VDR in C2C12 myoblasts (VDR-KD) and examined mitochondrial respiration and protein content compared with an shRNA scrambled control. VDR protein content was reduced by ~95% in myoblasts and myotubes ( P < 0.001). VDR-KD myoblasts displayed a 30%, 30%, and 36% reduction in basal, coupled, and maximal respiration, respectively ( P < 0.05). This phenotype was maintained in VDR-KD myotubes, displaying a 34%, 33%, and 48% reduction in basal, coupled, and maximal respiration ( P < 0.05). Furthermore, ATP production derived from oxidative phosphorylation (ATPOx) was reduced by 20%, suggesting intrinsic impairments within the mitochondria following VDR-KD. However, despite the observed functional decrements, mitochondrial protein content, as well as markers of mitochondrial fission were unchanged. In summary, we highlight a direct role for the VDR in regulating skeletal muscle mitochondrial respiration in vitro, providing a potential mechanism as to how vitamin D deficiency might impact upon skeletal muscle oxidative capacity.

scholarly journals Vasodilatory function in human skeletal muscle feed arteries with advancing age: the role of adropin

2019 ◽  
Vol 597 (7) ◽  
pp. 1791-1804 ◽  
Author(s):  
Oh Sung Kwon ◽  
Robert H. I. Andtbacka ◽  
John R. Hyngstrom ◽  
Russell S. Richardson
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Vasodilatory Function ◽  
Feed Arteries ◽  
Skeletal Muscle Feed Arteries

The Role of TRPV Ion Channels in Heat-induced Sympatholysis of Human Skeletal Muscle Feed Arteries

2014 ◽  
Vol 46 ◽  
pp. 328-329
Author(s):  
Jayson R. Gifford ◽  
Stephen J. Ives ◽  
Song Y. Park ◽  
Robert H.I. Andtbacka ◽  
Joel D. Trinity ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Ion Channels ◽  
Human Skeletal Muscle ◽  
Feed Arteries ◽  
Skeletal Muscle Feed Arteries

scholarly journals Role of vascular bed compliance in vasomotor control in human skeletal muscle

2007 ◽  
Vol 92 (5) ◽  
pp. 841-848 ◽  
Author(s):  
M. Zamir ◽  
R. Goswami ◽  
D. Salzer ◽  
J. K. Shoemaker
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Vasomotor Control ◽  
Vascular Bed
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