scholarly journals Effect of resistance exercise intensity on the expression of PGC-1α isoforms and the anabolic and catabolic signaling mediators, IGF-1 and myostatin, in human skeletal muscle

2016 ◽  
Vol 41 (8) ◽  
pp. 856-863 ◽  
Author(s):  
Neil A. Schwarz ◽  
Sarah K. McKinley-Barnard ◽  
Mike B. Spillane ◽  
Thomas L. Andre ◽  
Joshua J. Gann ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Mrna Expression ◽  
Exercise Intensity ◽  
Human Skeletal Muscle ◽  
Peroxisome Proliferator ◽  
Transcriptional Expression ◽  
Lower Intensity ◽  
Peroxisome Proliferator Activated Receptor ◽  
Body Resistance

The purpose of this study was to investigate the acute messenger (mRNA) expression of the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) isoforms, insulin-like growth factor-1Ea (IGF-1Ea), and myostatin in response to 2 resistance exercise intensities. In a uniform-balanced, crossover design, 10 participants performed 2 separate testing sessions involving a lower body resistance exercise component consisting of a lower intensity (50% of 1-repetition maximum; 1RM) protocol and a higher intensity (80% of 1RM) protocol of equal volumes. Muscle samples were obtained at before exercise, 45 min, 3 h, 24 h, and 48 h postexercise. Resistance exercise did not alter total PGC-1α mRNA expression; however, distinct responses of each PGC-1α isoform were observed. The response of each isoform was consistent between sessions, suggesting no effect of resistance exercise intensity on the complex transcriptional expression of the PGC-1α gene. IGF-1Ea mRNA expression significantly increased following the higher intensity session compared with pre-exercise and the lower intensity session. Myostatin mRNA expression was significantly reduced compared with pre-exercise values at all time points with no difference between exercise intensity. Further research is needed to determine the effects of the various isoforms of PGC-1α in human skeletal muscle on the translational level as well as their relation to the expression of IGF-1 and myostatin.

scholarly journals Effect of Resistance Exercise Intensity on the mRNA Expression of PGC-1α Isoforms in Human Skeletal Muscle

2015 ◽  
Vol 47 ◽  
pp. 188
Author(s):  
Neil A. Schwarz ◽  
Sarah K. McKinley ◽  
Mike Spillane ◽  
Joshua J. Gann ◽  
Thomas L. Andre ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Mrna Expression ◽  
Exercise Intensity ◽  
Human Skeletal Muscle

Pyruvate dehydrogenase activation and kinase expression in human skeletal muscle during fasting

2004 ◽  
Vol 96 (6) ◽  
pp. 2082-2087 ◽  
Author(s):  
Lawrence L. Spriet ◽  
Rebecca J. Tunstall ◽  
Matthew J. Watt ◽  
Kate A. Mehan ◽  
Mark Hargreaves ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Pyruvate Dehydrogenase ◽  
Human Skeletal Muscle ◽  
Mrna Abundance ◽  
Whole Body ◽  
Peroxisome Proliferator ◽  
Transcriptional Activators ◽  
Subsequent Increase ◽  
Peroxisome Proliferator Activated Receptor

Fasting forces adaptive changes in whole body and skeletal muscle metabolism that increase fat oxidation and decrease the oxidation of carbohydrate. We tested the hypothesis that 40 h of fasting would decrease pyruvate dehydrogenase (PDH) activity and increase PDH kinase (PDK) isoform mRNA expression in human skeletal muscle. The putative transcriptional activators of PDK isozymes, peroxisome proliferator-activated receptor-α (PPAR-α) protein, and forkhead homolog in rhabdomyosarcoma (FKHR) mRNA were also measured. Eleven healthy adults fasted after a standard meal (25% fat, 60% carbohydrate, 15% protein) with blood and skeletal muscle samples taken at 3, 15, and 40 h postprandial. Fasting increased plasma free fatty acid, glycerol, and β-hydroxybutyrate concentrations and decreased glucose and insulin concentrations. PDH activity decreased from 0.88 ± 0.11 mmol acetyl-CoA · min-1 · kg wet muscle wt-1 at 3 h to 0.62 ± 0.10 ( P = not significant) and 0.39 ± 0.06 ( P < 0.05) mmol · min-1 · kg wet mass-1 after 15 and 40 h of fasting. Although all four PDK isoforms were expressed in human skeletal muscle, PDK-2 and -4 mRNA were the most abundant. PDK-1 and -3 mRNA abundance was ∼1 and 15% of the PDK-2 and -4 levels, respectively. The 40-h fast had no effect on PDK-1, -2, and -3 mRNA expression. PDK-4 mRNA was significantly increased ∼3-fold after 15 h and ∼14-fold after 40 h of fasting. Skeletal muscle PPAR-α protein and FKHR mRNA abundance were unaffected by the fast. The results suggest that decreased PDH activation after 40 h of fasting may have been a function of the large increase in PDK-4 mRNA expression and possible subsequent increase in PDK protein and activity. The changes in PDK-4 expression and PDH activity did not coincide with increases in the transcriptional activators PPAR-α and FKHR.

scholarly journals Impact of acetaminophen consumption and resistance exercise on extracellular matrix gene expression in human skeletal muscle

2017 ◽  
Vol 313 (1) ◽  
pp. R44-R50 ◽  
Author(s):  
Shivam H. Patel ◽  
Andrew C. D’Lugos ◽  
Erica R. Eldon ◽  
Donald Curtis ◽  
Jared M. Dickinson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Resistance Exercise ◽  
Mrna Expression ◽  
Human Skeletal Muscle ◽  
Type I Collagen ◽  
Type Iii Collagen ◽  
Type I ◽  
Matrix Gene ◽  
The Impact

Acetaminophen (APAP) given during chronic exercise reduces skeletal muscle collagen and cross-linking in rats. We propose that the effect of APAP on muscle extracellular matrix (ECM) may, in part, be mediated by dysregulation of the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs). The purpose of this study was to evaluate the impact of APAP consumption during acute resistance exercise (RE) on several regulators of the ECM in human skeletal muscle. In a double-blinded, placebo-controlled, randomized crossover design, recreationally active men ( n = 8, 25 ± 2 yr) performed two trials of knee extension. Placebo (PLA) or APAP (1,000 mg/6 h) was given for 24 h before and immediately following RE. Vastus lateralis biopsies were taken at baseline and 1 and 3 h post-RE. Quantitative RT-PCR was used to determine differences in mRNA expression. MMP-2, type I collagen, and type III collagen mRNA expression was not altered by exercise or APAP ( P > 0.05). When compared with PLA, TIMP-1 expression was lower at 1 h post-RE during APAP conditions but greater than PLA at 3 h post-RE ( P < 0.05). MMP-9 expression and protein levels were elevated at 3 h post-RE independent of treatment ( P < 0.05). Lysyl oxidase expression was greater at 3 h post-RE during APAP consumption ( P < 0.05) compared with PLA. MMP-2 and TIMP-1 protein was not altered by RE or APAP ( P > 0.05). Phosphorylation of ERK1/2 and p38-MAPK increased ( P < 0.05) with RE but was not influenced by APAP. Our findings do not support our hypothesis and suggest that short-term APAP consumption before RE has a small impact on the measured ECM molecules in human skeletal muscle following acute RE.

Fasting and exercise differentially regulate BDNF mRNA expression in human skeletal muscle

2015 ◽  
Vol 40 (1) ◽  
pp. 96-98 ◽  
Author(s):  
Jeremy J. Walsh ◽  
Brittany A. Edgett ◽  
Michael E. Tschakovsky ◽  
Brendon J. Gurd
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Neurotrophic Factor ◽  
Human Skeletal Muscle ◽  
Peroxisome Proliferator ◽  
Bdnf Gene ◽  
Bdnf Mrna ◽  
Peroxisome Proliferator Activated Receptor ◽  
Energetic Stress ◽  
Future Work

Brain-derived neurotrophic factor (BDNF) gene expression was measured in human skeletal muscle following 3 intensities of exercise and a 48-h fast. No change in BDNF mRNA was observed following exercise, while fasting upregulated BDNF by ∼3.5-fold. These changes were dissociated from changes in peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) following exercise (+2- to 15-fold) and fasting (∼–25%). These results challenge our understanding of the response of BDNF to energetic stress and highlight the importance of future work in this area.

scholarly journals An Increase in Murine Skeletal Muscle Peroxisome Proliferator-Activated Receptor-γ Coactivator-1α (PGC-1α) mRNA in Response to Exercise Is Mediated by β-Adrenergic Receptor Activation

Endocrinology ◽  
2007 ◽  
Vol 148 (7) ◽  
pp. 3441-3448 ◽  
Author(s):  
Shinji Miura ◽  
Kentaro Kawanaka ◽  
Yuko Kai ◽  
Mayumi Tamura ◽  
Masahide Goto ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Adrenergic Receptor ◽  
Ex Vivo ◽  
Specific Inhibitor ◽  
Receptor Activation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Brown Adipose ◽  
Exercise Induced

A single bout of exercise increases expression of peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α mRNA, which may promote mitochondrial biogenesis in skeletal muscle. In brown adipose tissue, cold exposure up-regulates PGC-1α expression via adrenergic receptor (AR) activation. Because exercise also activates the sympathetic nervous system, we examined whether exercise-induced increase in PGC-1α mRNA expression in skeletal muscle was mediated via AR activation. In C57BL/6J mice, injection of the β2-AR agonist clenbuterol, but not α-, β1-, or β3-AR agonists, increased PGC-1α mRNA expression more than 30-fold in skeletal muscle. The clenbuterol-induced increase in PGC-1α mRNA expression in mice was inhibited by pretreatment with the β-AR antagonist propranolol. In ex vivo experiments, direct exposure of rat epitrochlearis to β2-AR agonist, but not α-, β1-, and β3-AR agonist, led to an increase in levels of PGC-1α mRNA. Injection of β2-AR agonist did not increase PGC-1α mRNA expression in β1-, β2-, and β3-AR knockout mice (β-less mice). PGC-1α mRNA in gastrocnemius was increased 3.5-fold in response to running on a treadmill for 45 min. The exercise-induced increase in PGC-1α mRNA was inhibited by approximately 70% by propranolol or the β2-AR-specific inhibitor ICI 118,551. The exercise-induced increase in PGC-1α mRNA in β-less mice was also 36% lower than that in wild-type mice. These data indicate that up-regulation of PGC-1α expression in skeletal muscle by exercise is mediated, at least in part, by β-ARs activation. Among ARs, β2-AR may mediate an increase in PGC-1α by exercise.

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