Activation of aconitase in mouse fast-twitch skeletal muscle during contraction-mediated oxidative stress

2007 ◽  
Vol 293 (3) ◽  
pp. C1154-C1159 ◽  
Author(s):  
Shi-Jin Zhang ◽  
Marie E. Sandström ◽  
Johanna T. Lanner ◽  
Anders Thorell ◽  
Håkan Westerblad ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Tricarboxylic Acid Cycle ◽  
Thigh Muscle ◽  
Ros Production ◽  
Atp Production ◽  
Aconitase Activity ◽  
Oxidation Reduction ◽  
Edl Muscle ◽  
Fast Twitch

Aconitase is a mitochondrial enzyme that converts citrate to isocitrate in the tricarboxylic acid cycle and is inactivated by reactive oxygen species (ROS). We investigated the effect of exercise/contraction, which is associated with elevated ROS production, on aconitase activity in skeletal muscle. Humans cycled at 75% of maximal workload, followed by six 60-s bouts at 125% of maximum workload. Biopsies were taken from the thigh muscle at rest and after the submaximal and supramaximal workloads. Isolated mouse extensor digitorum longus (EDL; fast twitch) and soleus (slow twitch) muscles were stimulated to perform repeated contractions for 10 min. Muscles were analyzed for enzyme activities and glutathione status. Exercise did not affect aconitase activity in human muscle despite increased oxidative stress, as judged by elevated levels of oxidized glutathione. Similarly, repeated contractions did not alter aconitase activity in soleus muscle. In contrast, repeated contractions significantly increased aconitase activity in EDL muscle by ∼50%, despite increased ROS production. This increase was not associated with a change in the amount of immunoreactive aconitase (Western blot) but was markedly inhibited by cyclosporin A, an inhibitor of the protein phosphatase calcineurin. Immunoprecipitation experiments demonstrated that aconitase was phosphorylated on serine residues. Aconitase in cell-free extracts was inactivated by the addition of the ROS hydrogen peroxide. In conclusion, the results suggest that aconitase activity can be regulated by at least two mechanisms: oxidation/reduction and phosphorylation/dephosphorylation. During contraction, a ROS-mediated inactivation of aconitase can be overcome, possibly by dephosphorylation of the enzyme. The dual-control system may be important in maintaining aerobic ATP production during muscle contraction.

scholarly journals Fibre-type specific modification of the activity and regulation of skeletal muscle pyruvate dehydrogenase kinase (PDK) by prolonged starvation and refeeding is associated with targeted regulation of PDK isoenzyme 4 expression

2000 ◽  
Vol 346 (3) ◽  
pp. 651-657 ◽  
Author(s):  
Mary C. SUGDEN ◽  
Alexandra KRAUS ◽  
Robert A. HARRIS ◽  
Mark J. HOLNESS
Keyword(s):  
Skeletal Muscle ◽  
Protein Expression ◽  
Pyruvate Dehydrogenase ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Pyruvate Dehydrogenase Kinase ◽  
Acid Cycle ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Anterior Tibialis

Using immunoblot analysis with antibodies raised against recombinant pyruvate dehydrogenase kinase (PDK) isoenzymes PDK2 and PDK4, we demonstrate selective changes in PDK isoenzyme expression in slow-twitch versus fast-twitch skeletal muscle types in response to prolonged (48 h) starvation and refeeding after starvation. Starvation increased PDK activity in both slow-twitch (soleus) and fast-twitch (anterior tibialis) skeletal muscle and was associated with loss of sensitivity of PDK to inhibition by pyruvate, with a greater effect in anterior tibialis. Starvation significantly increased PDK4 protein expression in both soleus and anterior tibialis, with a greater response in anterior tibialis. Starvation did not effect PDK2 protein expression in soleus, but modestly increased PDK2 expression in anterior tibialis. Refeeding for 4 h partially reversed the effect of 48-h starvation on PDK activity and PDK4 expression in both soleus and anterior tibialis, but the response was more marked in soleus than in anterior tibialis. Pyruvate sensitivity of PDK activity was also partially restored by refeeding, again with the greater response in soleus. It is concluded that targeted regulation of PDK4 isoenzyme expression in skeletal muscle in response to starvation and refeeding underlies the modulation of the regulatory characteristics of PDK in vivo. We propose that switching from a pyruvate-sensitive to a pyruvate-insensitive PDK isoenzyme in starvation (a) maintains a sufficiently high pyruvate concentration to ensure that the glucose → alanine → glucose cycle is not impaired, and (b) may ‘spare’ pyruvate for anaplerotic entry into the tricarboxylic acid cycle to support the entry of acetyl-CoA derived from fatty acid (FA) oxidation into the tricarboxylic acid cycle. We further speculate that FA oxidation by skeletal muscle is both forced and facilitated by upregulation of PDK4, which is perceived as an essential component of the operation of the glucose-FA cycle in starvation.

scholarly journals Oxidative Stress Evokes a Metabolic Adaptation That Favors Increased NADPH Synthesis and Decreased NADH Production in Pseudomonas fluorescens

2007 ◽  
Vol 189 (18) ◽  
pp. 6665-6675 ◽  
Author(s):  
Ranji Singh ◽  
Ryan J. Mailloux ◽  
Simone Puiseux-Dao ◽  
Vasu D. Appanna
Keyword(s):  
Oxidative Stress ◽  
Metabolic Pathways ◽  
Metabolic Networks ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Metabolic Adaptation ◽  
Atp Production ◽  
Oxidative Challenge ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Oxidative Insult

ABSTRACT The fate of all aerobic organisms is dependent on the varying intracellular concentrations of NADH and NADPH. The former is the primary ingredient that fuels ATP production via oxidative phosphorylation, while the latter helps maintain the reductive environment necessary for this process and other cellular activities. In this study we demonstrate a metabolic network promoting NADPH production and limiting NADH synthesis as a consequence of an oxidative insult. The activity and expression of glucose-6-phosphate dehydrogenase, malic enzyme, and NADP+-isocitrate dehydrogenase, the main generators of NADPH, were markedly increased during oxidative challenge. On the other hand, numerous tricarboxylic acid cycle enzymes that supply the bulk of intracellular NADH were significantly downregulated. These metabolic pathways were further modulated by NAD+ kinase (NADK) and NADP+ phosphatase (NADPase), enzymes known to regulate the levels of NAD+ and NADP+. While in menadione-challenged cells, the former enzyme was upregulated, the phosphatase activity was markedly increased in control cells. Thus, NADK and NADPase play a pivotal role in controlling the cross talk between metabolic networks that produce NADH and NADPH and are integral components of the mechanism involved in fending off oxidative stress.

scholarly journals Mitochondrial-targeted antioxidants protect skeletal muscle against immobilization-induced muscle atrophy

2011 ◽  
Vol 111 (5) ◽  
pp. 1459-1466 ◽  
Author(s):  
Kisuk Min ◽  
Ashley J. Smuder ◽  
Oh-sung Kwon ◽  
Andreas N. Kavazis ◽  
Hazel H. Szeto ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Muscle Fibers ◽  
Skeletal Muscle Atrophy ◽  
Ros Production ◽  
Oxygen Species ◽  
Mitochondrial Ros ◽  
Protease Activation ◽  
Limb Immobilization

Prolonged periods of muscular inactivity (e.g., limb immobilization) result in skeletal muscle atrophy. Although it is established that reactive oxygen species (ROS) play a role in inactivity-induced skeletal muscle atrophy, the cellular pathway(s) responsible for inactivity-induced ROS production remain(s) unclear. To investigate this important issue, we tested the hypothesis that elevated mitochondrial ROS production contributes to immobilization-induced increases in oxidative stress, protease activation, and myofiber atrophy in skeletal muscle. Cause-and-effect was determined by administration of a novel mitochondrial-targeted antioxidant (SS-31) to prevent immobilization-induced mitochondrial ROS production in skeletal muscle fibers. Compared with ambulatory controls, 14 days of muscle immobilization resulted in significant muscle atrophy, along with increased mitochondrial ROS production, muscle oxidative damage, and protease activation. Importantly, treatment with a mitochondrial-targeted antioxidant attenuated the inactivity-induced increase in mitochondrial ROS production and prevented oxidative stress, protease activation, and myofiber atrophy. These results support the hypothesis that redox disturbances contribute to immobilization-induced skeletal muscle atrophy and that mitochondria are an important source of ROS production in muscle fibers during prolonged periods of inactivity.

scholarly journals Acidic ambiance induced post-oxidative stress affects AMPK- PGC1α-SIRT1 axis in the skeletal muscles of zebrafish Danio rerio Hamilton, 1822

2021 ◽  
Vol 64 (2) ◽  
pp. 191-198
Author(s):  
Sabarna Chowdhury ◽  
Subhendu K. Chatterjee ◽  
Samir Bhattacharya ◽  
Sudipta Maitra ◽  
Surjya K. Saikia
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Mitochondrial Gene ◽  
Adaptive Strategy ◽  
Atp Production ◽  
Mitochondrial Functions ◽  
Metabolic Sensor ◽  
Metabolic Disruption ◽  
Complex I Activity

The present study was aimed to understand whether acidic pH induces oxidative stress in zebrafish affecting metabolic sensor protein and thereby, the mitochondrial functions in the skeletal muscle of zebrafish. The experiments performed in aquaria involved the study of the changes of HIF1α, AMPK, PGC1α and SIRT1 levels together with the levels of mitochondrial Tfam and Nrf1. The results obtained from investigation of superoxide dismutase (SOD), catalase and glutathione revealed that the fish undergoes oxidative stress within a short duration of exposure to acidic ambiance. Further analysis with MDA and HIF1α helped to understand the effects of post oxidative stress on skeletal muscle of the fish at pH 5.0 (± 0.5). Of the three tissues studied (gill, brain and skeletal muscle) the effect was maximum in skeletal muscle as depicted by MDA level at 2 hours beyond which it declines augmenting death or mortality (15%) to the fish. Consequently, HIF1α was increased as an adaptive strategy against metabolic disruption during the first 2 hours period. However, on exposure to pH 5.0 (± 0.5) for 2 hours, there were decrease of the metabolic sensors viz. AMPK and SIRT1 followed by mitochondrial gene transcriptional co-activator PGC1α. The expression of mitochon-drial transcription factors Tfam and Nrf1 were also reduced confirming perturbation in mitochondrial function affecting low ATP production compared to control. This was also supported by the decrease of COXII as well as mitochondrial complex I activity. All these results confirm that the metabolic machinery of zebrafish is affected when pH was lowered to 5.0 (± 0.5).

scholarly journals Preserved Skeletal Muscle Mitochondrial Function, Redox State, Inflammation and Mass in Obese Mice with Chronic Heart Failure

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3393
Author(s):  
Gianluca Gortan Cappellari ◽  
Aneta Aleksova ◽  
Matteo Dal Ferro ◽  
Antonio Cannatà ◽  
Annamaria Semolic ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Insulin Signaling ◽  
Redox State ◽  
Excess Body Weight ◽  
Ros Production ◽  
Atp Production ◽  
Mitochondrial Ros ◽  
Per Se ◽  
Muscle Mass Loss

Background: Skeletal muscle (SM) mitochondrial dysfunction, oxidative stress, inflammation and muscle mass loss may worsen prognosis in chronic heart failure (CHF). Diet-induced obesity may also cause SM mitochondrial dysfunction as well as oxidative stress and inflammation, but obesity per se may be paradoxically associated with high SM mass and mitochondrial adenosine triphosphate (ATP) production, as well as with enhanced survival in CHF. Methods: We investigated interactions between myocardial infarction(MI)-induced CHF and diet-induced obesity (12-wk 60% vs. standard 10% fat) in modulating gastrocnemius muscle (GM) mitochondrial ATP and tissue superoxide generation, oxidized glutathione (GSSG), cytokines and insulin signalling activation in 10-wk-old mice in the following groups: lean sham-operated, lean CHF (LCHF), obese CHF (ObCHF; all n = 8). The metabolic impact of obesity per se was investigated by pair-feeding ObCHF to standard diet with stabilized excess body weight until sacrifice at wk 8 post-MI. Results: Compared to sham, LCHF had low GM mass, paralleled by low mitochondrial ATP production and high mitochondrial reative oxygen species (ROS) production, pro-oxidative redox state, pro-inflammatory cytokine changes and low insulin signaling (p < 0.05). In contrast, excess body weight in pair-fed ObCHF was associated with high GM mass, preserved mitochondrial ATP and mitochondrial ROS production, unaltered redox state, tissue cytokines and insulin signaling (p = non significant vs. Sham, p < 0.05 vs. LCHF) despite higher superoxide generation from non-mitochondrial sources. Conclusions: CHF disrupts skeletal muscle mitochondrial function in lean rodents with low ATP and high mitochondrial ROS production, associated with tissue pro-inflammatory cytokine profile, low insulin signaling and muscle mass loss. Following CHF onset, obesity per se is associated with high skeletal muscle mass and preserved tissue ATP production, mitochondrial ROS production, redox state, cytokines and insulin signaling. These paradoxical and potentially favorable obesity-associated metabolic patterns could contribute to reported obesity-induced survival advantage in CHF.

Stanozolol treatment decreases the mitochondrial ROS generation and oxidative stress induced by acute exercise in rat skeletal muscle

2011 ◽  
Vol 110 (3) ◽  
pp. 661-669 ◽  
Author(s):  
Ana Saborido ◽  
Alba Naudí ◽  
Manuel Portero-Otín ◽  
Reinald Pamplona ◽  
Alicia Megías
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Fatty Acid Composition ◽  
Mitochondrial Membrane ◽  
Acute Exercise ◽  
Ros Generation ◽  
Ros Production ◽  
Rat Skeletal Muscle ◽  
Mitochondrial Ros ◽  
Exercise Induced

Anabolic androgenic steroids are used in the sport context to enhance muscle mass and strength and to increase muscle fatigue resistance. Since muscle fatigue has been related to oxidative stress caused by an exercise-linked reactive oxygen species (ROS) production, we investigated the potential effects of a treatment with the anabolic androgenic steroid stanozolol against oxidative damage induced on rat skeletal muscle mitochondria by an acute bout of exhaustive exercise. Mitochondrial ROS generation with complex I- and complex II-linked substrates was increased in exercised control rats, whereas it remained unchanged in the steroid-treated animals. Stanozolol treatment markedly reduced the extent of exercise-induced oxidative damage to mitochondrial proteins, as indicated by the lower levels of the specific markers of protein oxidation, glycoxidation, and lipoxidation, and the preservation of the activity of the superoxide-sensitive enzyme aconitase. This effect was not due to an enhancement of antioxidant enzyme activities. Acute exercise provoked changes in mitochondrial membrane fatty acid composition characterized by an increased content in docosahexaenoic acid. In contrast, the postexercise mitochondrial fatty acid composition was not altered in stanozolol-treated rats. Our results suggest that stanozolol protects against acute exercise-induced oxidative stress by reducing mitochondrial ROS production, in association with a preservation of mitochondrial membrane properties.

scholarly journals Zinc Protects Oxidative Stress-Induced RPE Death by Reducing Mitochondrial Damage and Preventing Lysosome Rupture

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Dinusha Rajapakse ◽  
Tim Curtis ◽  
Mei Chen ◽  
Heping Xu
Keyword(s):  
Oxidative Stress ◽  
Zinc Deficiency ◽  
Cathepsin B ◽  
Zinc Supplementation ◽  
Culture Conditions ◽  
Ros Production ◽  
Rpe Cells ◽  
Serum Free ◽  
Normal Culture ◽  
Atp Production

Zinc deficiency is known to increase the risk of the development of age-related macular degeneration (AMD), although the underlying mechanism remains poorly defined. In this study, we investigated the effect of zinc on retinal pigment epithelium (RPE) survival and function under oxidative conditions. Zinc level was 5.4 μM in normal culture conditions (DMEM/F12 with 10% FCS) and 1.5 μM in serum-free medium (DMEM/F12). Under serum-free culture conditions, the treatment of RPE cells with oxidized photoreceptor outer segment (oxPOS) significantly increased intracellular ROS production, reduced ATP production, and promoted RPE death compared to oxPOS-treated RPE under normal culture condition. Serum deprivation also reduced RPE phagocytosis of oxPOS and exacerbated oxidative insult-induced cathepsin B release from lysosome, an indicator of lysosome rupture. The addition of zinc in the serum-free culture system dose dependently reduced ROS production, recovered ATP production, and reduced oxidative stress- (oxPOS- or 4-HNE) induced cell death. Zinc supplementation also reduced oxidative stress-mediated cathepsin B release in RPE cells. Our results suggest that zinc deficiency sensitizes RPE cells to oxidative damage, and zinc supplementation protects RPE cells from oxidative stress-induced death by improving mitochondrial function and preventing lysosome rupture.

A gene for speed: contractile properties of isolated whole EDL muscle from an α-actinin-3 knockout mouse

2008 ◽  
Vol 295 (4) ◽  
pp. C897-C904 ◽  
Author(s):  
S. Chan ◽  
J. T. Seto ◽  
D. G. MacArthur ◽  
N. Yang ◽  
K. N. North ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mechanical Stability ◽  
Relaxation Times ◽  
Endurance Performance ◽  
Contractile Properties ◽  
Actin Binding ◽  
Power Performance ◽  
Cross Sectional ◽  
Edl Muscle ◽  
Fast Twitch

The actin-binding protein α-actinin-3 is one of the two isoforms of α-actinin that are found in the Z-discs of skeletal muscle. α-Actinin-3 is exclusively expressed in fast glycolytic muscle fibers. Homozygosity for a common polymorphism in the ACTN3 gene results in complete deficiency of α-actinin-3 in about 1 billion individuals worldwide. Recent genetic studies suggest that the absence of α-actinin-3 is detrimental to sprint and power performance in elite athletes and in the general population. In contrast, α-actinin-3 deficiency appears to be beneficial for endurance athletes. To determine the effect of α-actinin-3 deficiency on the contractile properties of skeletal muscle, we studied isolated extensor digitorum longus (fast-twitch) muscles from a specially developed α-actinin-3 knockout (KO) mouse. α-Actinin-3-deficient muscles showed similar levels of damage to wild-type (WT) muscles following lengthening contractions of 20% strain, suggesting that the presence or absence of α-actinin-3 does not significantly influence the mechanical stability of the sarcomere in the mouse. α-Actinin-3 deficiency does not result in any change in myosin heavy chain expression. However, compared with α-actinin-3-positive muscles, α-actinin-3-deficient muscles displayed longer twitch half-relaxation times, better recovery from fatigue, smaller cross-sectional areas, and lower twitch-to-tetanus ratios. We conclude that α-actinin-3 deficiency results in fast-twitch, glycolytic fibers developing slower-twitch, more oxidative properties. These changes in the contractile properties of fast-twitch skeletal muscle from α-actinin-3-deficient individuals would be detrimental to optimal sprint and power performance, but beneficial for endurance performance.

scholarly journals Oxidative Metabolism Genes Are Not Responsive to Oxidative Stress in Rodent Beta Cell Lines

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Faer Morrison ◽  
Karen Johnstone ◽  
Anna Murray ◽  
Jonathan Locke ◽  
Lorna W. Harries
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Beta Cell ◽  
Beta Cells ◽  
Oxidative Metabolism ◽  
Pancreatic Beta Cells ◽  
Ros Production ◽  
Altered Expression ◽  
Beta Cell Line

Altered expression of oxidative metabolism genes has been described in the skeletal muscle of individuals with type 2 diabetes. Pancreatic beta cells contain low levels of antioxidant enzymes and are particularly susceptible to oxidative stress. In this study, we explored the effect of hyperglycemia-induced oxidative stress on a panel of oxidative metabolism genes in a rodent beta cell line. We exposed INS-1 rodent beta cells to low (5.6 mmol/L), ambient (11 mmol/L), and high (28 mmol/L) glucose conditions for 48 hours. Increases in oxidative stress were measured using the fluorescent probe dihydrorhodamine 123. We then measured the expression levels of a panel of 90 oxidative metabolism genes by real-time PCR. Elevated reactive oxygen species (ROS) production was evident in INS-1 cells after 48 hours (P<0.05). TLDA analysis revealed a significant (P<0.05) upregulation of 16 of the 90 genes under hyperglycemic conditions, although these expression differences did not reflect differences in ROS. We conclude that although altered glycemia may influence the expression of some oxidative metabolism genes, this effect is probably not mediated by increased ROS production. The alterations to the expression of oxidative metabolism genes previously observed in human diabetic skeletal muscle do not appear to be mirrored in rodent pancreatic beta cells.

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