Subcellular fractionation reveals HSP72 does not associate with SERCA in human skeletal muscle following damaging eccentric and concentric exercise

2014 ◽  
Vol 116 (11) ◽  
pp. 1503-1511 ◽  
Author(s):  
Noni T. Frankenberg ◽  
Graham D. Lamb ◽  
Kristian Vissing ◽  
Robyn M. Murphy
Keyword(s):  
Skeletal Muscle ◽  
Protein Content ◽  
Human Skeletal Muscle ◽  
Physiological Stress ◽  
Vastus Lateralis ◽  
Tight Binding ◽  
Fold Increase ◽  
Subcellular Fractionation ◽  
Vastus Lateralis Muscle ◽  
Type I

Through its upregulation and/or translocation, heat shock protein 72 (HSP72) is involved in protection and repair of key proteins after physiological stress. In human skeletal muscle we investigated HSP72 protein after eccentric (ECC1) and concentric (CONC) exercise and repeated eccentric exercise (ECC2; 8 wk later) and whether it translocated from its normal cytosolic location to membranes/myofibrils. HSP72 protein increased ∼2-fold 24 h after ECC1, with no apparent change after CONC or ECC2. In resting (nonstressed) human skeletal muscle the total pool of HSP72 protein was present almost exclusively in the cytosolic fraction, and after each exercise protocol the distribution of HSP72 protein remained unaltered. Overall, the amount of HSP72 protein in the cytosol increased 24 h after ECC1, matching the fold increase that was measured in total HSP72 protein. To better ascertain the capabilities and limitations of HSP72, using quantitative Western blotting we determined the HSP72 protein content to be 11.4 μmol/kg wet weight in resting human vastus lateralis muscle, which is comprised of Type I (slow-twitch) and Type II (fast-twitch) fibers. HSP72 protein content was similar in individual Type I or II fiber segments. After physiological stress, HSP72 content can increase and, although the functional consequences of increased amounts of HSP72 protein are poorly understood, it has been shown to bind to and protect protein pumps like SERCA and Na+-K+-ATPase. Given no translocation of cytosolic HSP72, these findings suggest eccentric contractions, unlike other forms of stress such as heat, do not trigger tight binding of HSP72 to its primary membrane-bound target proteins, in particular SERCA.

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.

Single-fiber expression and fiber-specific adaptability to short-term intense exercise training of Na+-K+-ATPase α- and β-isoforms in human skeletal muscle

2015 ◽  
Vol 118 (6) ◽  
pp. 699-706 ◽  
Author(s):  
V. L. Wyckelsma ◽  
M. J. McKenna ◽  
F. R. Serpiello ◽  
C. R. Lamboley ◽  
R. J. Aughey ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Western Blotting ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Single Fiber ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Functional Roles

The Na+-K+-ATPase (NKA) plays a key role in muscle excitability, but little is known in human skeletal muscle about fiber-type-specific differences in NKA isoform expression or adaptability. A vastus lateralis muscle biopsy was taken in 17 healthy young adults to contrast NKA isoform protein relative abundance between type I and IIa fibers. We further investigated muscle fiber-type-specific NKA adaptability in eight of these adults following 4-wk repeated-sprint exercise (RSE) training, comprising three sets of 5 × 4-s sprints, 3 days/wk. Single fibers were separated, and myosin heavy chain (I and IIa) and NKA (α1–3 and β1–3) isoform abundance were determined via Western blotting. All six NKA isoforms were expressed in both type I and IIa fibers. No differences between fiber types were found for α1-, α2-, α3-, β1-, or β3-isoform abundances. The NKA β2-isoform was 27% more abundant in type IIa than type I fibers ( P < 0.05), with no other fiber-type-specific trends evident. RSE training increased β1 in type IIa fibers (pretraining 0.70 ± 0.25, posttraining 0.84 ± 0.24 arbitrary units, 42%, P < 0.05). No training effects were found for other NKA isoforms. Thus human skeletal muscle expresses all six NKA isoforms and not in a fiber-type-specific manner; this points to their different functional roles in skeletal muscle cells. Detection of elevated NKA β1 after RSE training demonstrates the sensitivity of the single-fiber Western blotting technique for fiber-type-specific intervention effects.

Gene Polymorphisms and Fiber-Type Composition of Human Skeletal Muscle

2012 ◽  
Vol 22 (4) ◽  
pp. 292-303 ◽  
Author(s):  
Ildus I. Ahmetov ◽  
Olga L. Vinogradova ◽  
Alun G. Williams
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Type I Fibers

The ability to perform aerobic or anaerobic exercise varies widely among individuals, partially depending on their muscle-fiber composition. Variability in the proportion of skeletal-muscle fiber types may also explain marked differences in aspects of certain chronic disease states including obesity, insulin resistance, and hypertension. In untrained individuals, the proportion of slow-twitch (Type I) fibers in the vastus lateralis muscle is typically around 50% (range 5–90%), and it is unusual for them to undergo conversion to fast-twitch fibers. It has been suggested that the genetic component for the observed variability in the proportion of Type I fibers in human muscles is on the order of 40–50%, indicating that muscle fiber-type composition is determined by both genotype and environment. This article briefly reviews current progress in the understanding of genetic determinism of fiber-type proportion in human skeletal muscle. Several polymorphisms of genes involved in the calcineurin–NFAT pathway, mitochondrial biogenesis, glucose and lipid metabolism, cytoskeletal function, hypoxia and angiogenesis, and circulatory homeostasis have been associated with fiber-type composition. As muscle is a major contributor to metabolism and physical strength and can readily adapt, it is not surprising that many of these gene variants have been associated with physical performance and athlete status, as well as metabolic and cardiovascular diseases. Genetic variants associated with fiber-type proportions have important implications for our understanding of muscle function in both health and disease.

Phosphorylase a in human skeletal muscle during exercise and electrical stimulation

1978 ◽  
Vol 45 (6) ◽  
pp. 852-857 ◽  
Author(s):  
P. D. Gollnick ◽  
J. Karlsson ◽  
K. Piehl ◽  
B. Saltin
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Muscular Activity ◽  
Voluntary Exercise ◽  
Vastus Lateralis Muscle ◽  
Minor Importance ◽  
Muscle Lactate ◽  
Needle Technique

Experiments were conducted to examine the conversions of phosphorylase b to phosphorylase a in human skeletal muscle during bicycle exercise or isometric contractions. Muscle biopsies were obtained from the vastus lateralis with the needle technique at rest and either during or immediately after activity and frozen in liquid nitrogen within 2--4 s. Total phosphorylase and phosphorylase a activities were differentiated by measurement in the presence and absence of AMP, respectively. At rest 8.5% of the total phosphorylase activity existed in the a form. Little or no change in the percent of phosphorylase in the a form occurred during voluntary dynamic or static muscular activity that produced muscle lactate concentrations in excess of 18 mmol.kg-1 wet muscle. Electrical stimulation of the vastus lateralis muscle also failed to produce an increase in the percentage of phosphorylase a. These data suggest that during exercise the conversion of phosphorylase to the a form is of minor importance. An increased activity of phosphorylase b due to changes in muscle concentrations of ATP, AMP, and inorganic phosphate may regulate glycogenolysis during voluntary exercise in man.

scholarly journals Contractile activity-specific transcriptome response to acute endurance exercise and training in human skeletal muscle

2019 ◽  
Vol 316 (4) ◽  
pp. E605-E614 ◽  
Author(s):  
Daniil V. Popov ◽  
Pavel A. Makhnovskii ◽  
Elena I. Shagimardanova ◽  
Guzel R. Gazizova ◽  
Evgeny A. Lysenko ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Transcription Factors ◽  
Human Skeletal Muscle ◽  
Acute Exercise ◽  
Contractile Activity ◽  
Vastus Lateralis ◽  
Aerobic Exercise Training ◽  
Vastus Lateralis Muscle ◽  
Transcriptome Response ◽  
The One

Reduction in daily activity leads to dramatic metabolic disorders, while regular aerobic exercise training is effective for preventing this problem. The purpose of this study was to identify genes that are directly related to contractile activity in human skeletal muscle, regardless of the level of fitness. Transcriptome changes after the one-legged knee extension exercise in exercised and contralateral nonexercised vastus lateralis muscle of seven men were evaluated by RNA-seq. Transcriptome change at baseline after 2 mo of aerobic training (5/wk, 1 h/day) was evaluated as well. Postexercise changes in the transcriptome of exercised muscle were associated with different factors, including circadian oscillations. To reveal transcriptome response specific for endurance-like contractile activity, differentially expressed genes between exercised and nonexercised muscle were evaluated at 1 and 4 h after the one-legged exercise. The contractile activity-specific transcriptome responses were associated only with an increase in gene expression and were regulated mainly by CREB/ATF/AP1-, MYC/MAX-, and E2F-related transcription factors. Endurance training-induced changes (an increase or decrease) in the transcriptome at baseline were more pronounced than transcriptome responses specific for acute contractile activity. Changes after training were associated with widely different biological processes than those after acute exercise and were regulated by different transcription factors (IRF- and STAT-related factors). In conclusion, adaptation to regular exercise is associated not only with a transient (over several hours) increase in expression of many contractile activity-specific genes, but also with a pronounced change (an increase or decrease) in expression of a large number of genes under baseline conditions.

Effect of exercise on insulin action in human skeletal muscle

1989 ◽  
Vol 66 (2) ◽  
pp. 876-885 ◽  
Author(s):  
E. A. Richter ◽  
K. J. Mikines ◽  
H. Galbo ◽  
B. Kiens
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Insulin Action ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Femoral Vein ◽  
Glycogen Synthesis ◽  
Vastus Lateralis Muscle ◽  
Glycogen Concentration ◽  
Local Contraction

The effect of 1 h of dynamic one-legged exercise on insulin action in human muscle was studied in 6 healthy young men. Four hours after one-legged knee extensions, a three-step sequential euglycemic hyperinsulinemic clamp combined with arterial and bilateral femoral vein catheterization was performed. Increased insulin action on glucose uptake was found in the exercised compared with the rested thigh at mean plasma insulin concentrations of 23, 40, and 410 microU/ml. Furthermore, prior contractions directed glucose uptake toward glycogen synthesis and increased insulin effects on thigh O2 consumption and at some insulin concentrations on potassium exchange. In contrast, no change in insulin effects on limb exchange of free fatty acids, glycerol, alanine or tyrosine were found after exercise. Glycogen concentration in rested vastus lateralis muscle did not increase measurably during the clamp even though indirect estimates indicated net glycogen synthesis. In contrast, in exercised muscle estimated and biopsy-verified increases in muscle glycogen concentration agreed. Local contraction-induced increases in insulin sensitivity and responsiveness play an important role in postexercise recovery of human skeletal muscle.

Human skeletal muscle malonyl-CoA at rest and during prolonged submaximal exercise

1996 ◽  
Vol 270 (3) ◽  
pp. E541-E544 ◽  
Author(s):  
L. M. Odland ◽  
G. J. Heigenhauser ◽  
G. D. Lopaschuk ◽  
L. L. Spriet
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
High Performance ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Submaximal Exercise ◽  
Acid Oxidation ◽  
Vastus Lateralis Muscle ◽  
Malonyl Coa

Previous literature has indicated that contraction-induced decreases in malonyl-CoA are instrumental in the regulation of fatty acid oxidation during prolonged submaximal exercise. This study was designed to measure malonyl-CoA in human vastus lateralis muscle at rest and during submaximal exercise. Eight males and one female cycled for 70 min (10 min at 40% and 60 min at 65% maximal O2 uptake). Needle biopsies were obtained at rest and at 10 min, 20 min, and 70 min of exercise. Malonyl-CoA content in preexercise biopsy samples determined by high-performance liquid chromatography (HPLC) was 1.53 +/- 0.18 micromol/kg dry mass (dm). Malonyl-CoA content did not change significantly during exercise (1.39 +/- 0.21 at 10 min, 1.46 +/- 0.14 at 20 min, and 1.22 +/- 0.15 micromol/kg dm at 70 min). In contrast, malonyl-CoA content determined by HPLC in perfused rat red gastrocnemius muscle decreased significantly during 20 min of stimulation at 0.7 Hz [3.44 +/- 0.54 to 1.64 +/- 0.23 nmol/g dm, (n=9)]. We conclude that human skeletal muscle malonyl-CoA content 1) is less than reported in rat skeletal muscle at rest, 2) does not decrease with prolonged submaximal exercise, and 3) is not predictive of increased fatty acid oxidation during exercise.

Thermogenesis in human skeletal muscle as measured by direct microcalorimetry and muscle contractile performance during β-adrenoceptor blockade

1986 ◽  
Vol 70 (5) ◽  
pp. 435-441 ◽  
Author(s):  
Birger Fagher ◽  
Hans Liedholm ◽  
Mario Monti ◽  
Ulrich Moritz
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Dynamic Strength ◽  
Peak Torque ◽  
Vastus Lateralis Muscle ◽  
Low Grade ◽  
Double Blind ◽  
Blind Test ◽  
Direct Calorimetry

1. The influence of β-adrenoceptor-blockade on skeletal muscle was studied in ten healthy males with propranolol, atenolol and pindolol randomly given for 8 days each in a cross-over double blind test. After 7 days on each drug, muscle function was tested by an isokinetic dynamometer. Thermogenesis in biopsy samples taken from vastus lateralis muscle after a low grade exercise was studied after 8 days on each drug by direct calorimetry with a perfusion microcalorimeter. 2. Before drug administration, a median heat production rate of 0.67 mW/g of muscle was measured. This value was significantly reduced by 25% during propranolol, but no significant change was found during atenolol or pindolol administration. 3. Peak torque decline during isokinetic endurance test changed significantly in knee flexor but not in extensor muscles, from 15% to 27% after propranolol and from 15% to 23% after pindolol. Maximum dynamic strength was unaltered. 4. Our data suggest that blockade of sympathetic β2-receptors decreases thermogenesis in human skeletal muscle and impairs isokinetic endurance.

Exercise adaptation attenuates VEGF gene expression in human skeletal muscle

2000 ◽  
Vol 279 (2) ◽  
pp. H772-H778 ◽  
Author(s):  
R. S. Richardson ◽  
H. Wagner ◽  
S. R. D. Mudaliar ◽  
E. Saucedo ◽  
R. Henry ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Human Skeletal Muscle ◽  
Acute Exercise ◽  
Vastus Lateralis ◽  
Northern Analysis ◽  
Endothelial Cell Proliferation ◽  
Vastus Lateralis Muscle ◽  
Mrna Levels ◽  
Exercise Adaptation

Angiogenesis is a component of the multifactoral adaptation to exercise training, and vascular endothelial growth factor (VEGF) is involved in extracellular matrix changes and endothelial cell proliferation. However, there is limited evidence supporting the role of VEGF in the exercise training response. Thus we studied mRNA levels of VEGF, using quantitative Northern analysis, in untrained and trained human skeletal muscle at rest and after a single bout of exercise. Single leg knee-extension provided the acute exercise stimulus and the training modality. Four biopsies were collected from the vastus lateralis muscle at rest in the untrained and trained conditions before and after exercise. Training resulted in a 35% increase in muscle oxygen consumption and an 18% increase in number of capillaries per muscle fiber. At rest, VEGF/18S mRNA levels were similar before (0.38 ± 0.04) and after (1.2 ± 0.4) training. When muscle was untrained, acute exercise greatly elevated VEGF/18S mRNA levels (16.9 ± 6.7). The VEGF/18S mRNA response to acute exercise in the trained state was markedly attenuated (5.4 ± 1.3). These data support the concept that VEGF is involved in exercise-induced skeletal muscle angiogenesis and appears to be subject to a negative feedback mechanism as exercise adaptations occur.

ATP-induced vasodilation and purinergic receptors in the human leg: roles of nitric oxide, prostaglandins, and adenosine

2009 ◽  
Vol 296 (4) ◽  
pp. R1140-R1148 ◽  
Author(s):  
Stefan P. Mortensen ◽  
José González-Alonso ◽  
Laurids T. Bune ◽  
Bengt Saltin ◽  
Henriette Pilegaard ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Human Skeletal Muscle ◽  
Purinergic Receptors ◽  
Vastus Lateralis ◽  
Muscle Blood Flow ◽  
Pcr Analysis ◽  
Receptor Subtypes ◽  
Vastus Lateralis Muscle

Plasma ATP is thought to contribute to the local regulation of skeletal muscle blood flow. Intravascular ATP infusion can induce profound limb muscle vasodilatation, but the purinergic receptors and downstream signals involved in this response remain unclear. This study investigated: 1) the role of nitric oxide (NO), prostaglandins, and adenosine as mediators of ATP-induced limb vasodilation and 2) the expression and distribution of purinergic P2 receptors in human skeletal muscle. Systemic and leg hemodynamics were measured before and during 5–7 min of femoral intra-arterial infusion of ATP [0.45–2.45 μmol/min] in 19 healthy male subjects with and without coinfusion of NG-monomethyl-l-arginine (l-NMMA; NO formation inhibitor; 12.3 ± 0.3 (SE) mg/min), indomethacin (INDO; prostaglandin formation blocker; 613 ± 12 μg/min), and/or theophylline (adenosine receptor blocker; 400 ± 26 mg). During control conditions, ATP infusion increased leg blood flow (LBF) from baseline conditions by 1.82 ± 0.14 l/min. When ATP was coinfused with either l-NMMA, INDO, or l-NMMA + INDO combined, the increase in LBF was reduced by 14 ± 6, 15 ± 9, and 39 ± 8%, respectively (all P < 0.05), and was associated with a parallel lowering in leg vascular conductance and cardiac output and a compensatory increase in leg O2 extraction. Infusion of theophylline did not alter the ATP-induced leg hyperemia or systemic variables. Real-time PCR analysis of the mRNA content from the vastus lateralis muscle of eight subjects showed the highest expression of P2Y2 receptors of the 10 investigated P2 receptor subtypes. Immunohistochemistry showed that P2Y2 receptors were located in the endothelium of microvessels and smooth muscle cells, whereas P2X1 receptors were located in the endothelium and the sacrolemma. Collectively, these results indicate that NO and prostaglandins, but not adenosine, play a role in ATP-induced vasodilation in human skeletal muscle. The expression and localization of the nucleotide selective P2Y2 and P2X1 receptors suggest that these receptors may mediate ATP-induced vasodilation in skeletal muscle.

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