scholarly journals Intake of branched-chain or essential amino acids attenuates the elevation in muscle levels of PGC-1α4 mRNA caused by resistance exercise

2016 ◽  
Vol 311 (1) ◽  
pp. E246-E251 ◽  
Author(s):  
Hedvig Samuelsson ◽  
Marcus Moberg ◽  
William Apró ◽  
Björn Ekblom ◽  
Eva Blomstrand
Keyword(s):  
Amino Acids ◽  
Protein Kinase ◽  
Resistance Exercise ◽  
Vastus Lateralis ◽  
Essential Amino Acids ◽  
Mitogen Activated Protein Kinase ◽  
Vastus Lateralis Muscle ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Branched Chain

The transcriptional coactivator peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α is recognized as the master regulator of mitochondrial biogenesis. However, recently a novel isoform, PGC-1α4, that specifically regulates muscle hypertrophy was discovered. Because stimulation of mechanistic target of rapamycin complex 1 (mTORC1) activity is tightly coupled to hypertrophy, we hypothesized that activation of this pathway would upregulate PGC-1α4. Eight male subjects performed heavy resistance exercise (10 × 8–12 repetitions at ∼75% of 1 repetition maximum in leg press) on four different occasions, ingesting in random order a solution containing essential amino acids (EAA), branched-chain amino acids (BCAA), leucine, or flavored water (placebo) during and after the exercise. Biopsies were taken from the vastus lateralis muscle before and immediately after exercise, as well as following 90 and 180 min of recovery. Signaling through mTORC1, as reflected in p70S6 kinase phosphorylation, was stimulated to a greater extent by the EAA and BCAA than the leucine or placebo supplements. Unexpectedly, intake of EAA or BCAA attenuated the stimulatory effect of exercise on PGC-1α4 expression by ∼50% (from a 10- to 5-fold increase with BCAA and EAA, P < 0.05) 3 h after exercise, whereas intake of leucine alone did not reduce this response. The 60% increase ( P < 0.05) in the level of PGC-1α1 mRNA 90 min after exercise was uninfluenced by amino acid intake. Muscle glycogen levels were reduced and AMP-activated protein kinase α2 activity and phosphorylation of p38 mitogen-activated protein kinase enhanced to the same extent with all four supplements. In conclusion, induction of PGC-1α4 does not appear to regulate the nutritional (BCAA or EAA)-mediated activation of mTORC1 in human muscle.

Branched-chain amino acids increase p70S6k phosphorylation in human skeletal muscle after resistance exercise

2004 ◽  
Vol 287 (1) ◽  
pp. E1-E7 ◽  
Author(s):  
Håkan K. R. Karlsson ◽  
Per-Anders Nilsson ◽  
Johnny Nilsson ◽  
Alexander V. Chibalin ◽  
Juleen R. Zierath ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Kinase ◽  
Resistance Exercise ◽  
P38 Mapk ◽  
Recovery Period ◽  
Plasma Concentrations ◽  
Branched Chain Amino Acids ◽  
Mitogen Activated Protein Kinase ◽  
Branched Chain

The aim of the study was to investigate the effect of resistance exercise alone or in combination with oral intake of branched-chain amino acids (BCAA) on phosphorylation of the 70-kDa S6 protein kinase (p70S6k) and mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK1/2), and p38 MAPK in skeletal muscle. Seven male subjects performed one session of quadriceps muscle resistance training (4 × 10 repetitions at 80% of one repetition maximum) on two occasions. In a randomized order, double-blind, crossover test, subjects ingested a solution of BCAA or placebo during and after exercise. Ingestion of BCAA increased plasma concentrations of isoleucine, leucine, and valine during exercise and throughout recovery after exercise (2 h postexercise), whereas no change was noted after the placebo trial. Resistance exercise led to a robust increase in p70S6k phosphorylation at Ser424 and/or Thr421, which persisted 1 and 2 h after exercise. BCAA ingestion further enhanced p70S6k phosphorylation 3.5-fold during recovery. p70S6k phosphorylation at Thr389 was unaltered directly after resistance exercise. However, during recovery, Thr389 phosphorylation was profoundly increased, but only during the BCAA trial. Furthermore, phosphorylation of the ribosomal protein S6 was also increased in the recovery period only during the BCAA trial. Exercise led to a marked increase in ERK1/2 and p38 MAPK phosphorylation, which was completely suppressed upon recovery and unaltered by BCAA. In conclusion, BCAA, ingested during and after resistance exercise, mediate signal transduction through p70S6k in skeletal muscle.

scholarly journals Influence of ageing and essential amino acids on quantitative patterns of troponin T alternative splicing in human skeletal muscle

2015 ◽  
Vol 40 (8) ◽  
pp. 788-796 ◽  
Author(s):  
Joel Coble ◽  
Rudolf J. Schilder ◽  
Arthur Berg ◽  
Micah J. Drummond ◽  
Blake B. Rasmussen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Alternative Splicing ◽  
Resistance Exercise ◽  
Troponin T ◽  
Vastus Lateralis ◽  
Essential Amino Acids ◽  
Muscle Performance ◽  
Muscle Quality ◽  
Vastus Lateralis Muscle

Ageing is associated with a loss of skeletal muscle performance, a condition referred to as sarcopenia. In part, the age-related reduction in performance is due to a selective loss of muscle fiber mass, but mass-independent effects have also been demonstrated. An important mass-independent determinant of muscle performance is the pattern of expression of isoforms of proteins that participate in muscle contraction (e.g., the troponins). In the present study, we tested the hypothesis that ageing impairs alternative splicing of the pre-mRNA encoding fast skeletal muscle troponin T (TNNT3) in human vastus lateralis muscle. Furthermore, we hypothesized that resistance exercise alone or in combination with consumption of essential amino acids would attenuate age-associated effects on TNNT3 alternative splicing. Our results indicate that ageing negatively affects the pattern of TNNT3 alternative splicing in a manner that correlates quantitatively with age-associated reductions in muscle performance. Interestingly, whereas vastus lateralis TNNT3 alternative splicing was unaffected by a bout of resistance exercise 24 h prior to muscle biopsy, ingestion of a mixture of essential amino acids after resistance exercise resulted in a significant shift in the pattern of TNNT3 splice form expression in both age groups to one predicted to promote greater muscle performance. We conclude that essential amino acid supplementation after resistance exercise may provide a means to reduce impairments in skeletal muscle quality during ageing in humans.

scholarly journals Peroxisome Proliferator-Activated Receptor γ Coactivator 1α Activates Vascular Endothelial Growth Factor That Protects Against Neuronal Cell Death Following Status Epilepticus through PI3K/AKT and MEK/ERK Signaling

2020 ◽  
Vol 21 (19) ◽  
pp. 7247
Author(s):  
Jyun-Bin Huang ◽  
Shih-Pin Hsu ◽  
Hsiu-Yung Pan ◽  
Shang-Der Chen ◽  
Shu-Fang Chen ◽  
...  
Keyword(s):  
Status Epilepticus ◽  
Protein Kinase ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Mitogen Activated Protein Kinase ◽  
Erk Signaling ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Mitogen Activated Protein ◽  
Hippocampal Ca3

Status epilepticus may cause molecular and cellular events, leading to hippocampal neuronal cell death. Peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) is an important regulator of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2), also known as fetal liver kinase receptor 1 (Flk-1). Resveratrol is an activator of PGC-1α. It has been suggested to provide neuroprotective effects in epilepsy, stroke, and neurodegenerative diseases. In the present study, we used microinjection of kainic acid into the left hippocampal CA3 region in Sprague Dawley rats to induce bilateral prolonged seizure activity. Upregulating the PGC-1α pathway will increase VEGF/VEGFR2 (Flk-1) signaling and further activate some survival signaling that includes the mitogen activated protein kinase kinase (MEK)/mitogen activated protein kinase (ERK) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathways and offer neuroprotection as a consequence of apoptosis in the hippocampal neurons following status epilepticus. Otherwise, downregulation of PGC-1α by siRNA against pgc-1α will inhibit VEGF/VEGFR2 (Flk-1) signaling and suppress pro-survival PI3K/AKT and MEK/ERK pathways that are also accompanied by hippocampal CA3 neuronal cell apoptosis. These results may indicate that the PGC-1α induced VEGF/VEGFR2 pathway may trigger the neuronal survival signaling, and the PI3K/AKT and MEK/ERK signaling pathways. Thus, the axis of PGC-1α/VEGF/VEGFR2 (Flk-1) and the triggering of downstream PI3K/AKT and MEK/ERK signaling could be considered an endogenous neuroprotective effect against apoptosis in the hippocampus following status epilepticus.

Eccentric exercise markedly increases c-Jun NH2-terminal kinase activity in human skeletal muscle

1999 ◽  
Vol 87 (5) ◽  
pp. 1668-1673 ◽  
Author(s):  
Marni D. Boppart ◽  
Doron Aronson ◽  
Lindsay Gibson ◽  
Ronenn Roubenoff ◽  
Leslie W. Abad ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Eccentric Exercise ◽  
Intracellular Signaling ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Fold Increase ◽  
Mitogen Activated Protein Kinase ◽  
Eccentric Contractions ◽  
Vastus Lateralis Muscle

Eccentric contractions require the lengthening of skeletal muscle during force production and result in acute and prolonged muscle injury. Because a variety of stressors, including physical exercise and injury, can result in the activation of the c-Jun NH2-terminal kinase (JNK) intracellular signaling cascade in skeletal muscle, we investigated the effects of eccentric exercise on the activation of this stress-activated protein kinase in human skeletal muscle. Twelve healthy subjects (7 men, 5 women) completed maximal concentric or eccentric knee extensions on a KinCom isokinetic dynamometer (10 sets, 10 repetitions). Percutaneous needle biopsies were obtained from the vastus lateralis muscle 24 h before exercise (basal), immediately postexercise, and 6 h postexercise. Whereas both forms of exercise increased JNK activity immediately postexercise, eccentric contractions resulted in a much higher activation (15.4 ± 4.5 vs. 3.5 ± 1.4-fold increase above basal, eccentric vs. concentric). By 6 h after exercise, JNK activity decreased back to baseline values. In contrast to the greater activation of JNK with eccentric exercise, the mitogen-activated protein kinase kinase 4, the immediate upstream regulator of JNK, was similarly activated by concentric and eccentric exercise. Because the activation of JNK promotes the phosphorylation of a variety of transcription factors, including c-Jun, the results from this study suggest that JNK may be involved in the molecular and cellular adaptations that occur in response to injury-producing exercise in human skeletal muscle.

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