Lack of myostatin alters intermyofibrillar mitochondria activity, unbalances redox status, and impairs tolerance to chronic repetitive contractions in muscle

2012 ◽  
Vol 302 (8) ◽  
pp. E1000-E1008 ◽  
Author(s):  
Claire Ploquin ◽  
Béatrice Chabi ◽  
Gilles Fouret ◽  
Barbara Vernus ◽  
Christine Feillet-Coudray ◽  
...  

Loss of myostatin (mstn) function leads to a decrease in mitochondrial content, a reduced expression of cytochrome c oxidase, and a lower citrate synthase activity in skeletal muscle. These data suggest functional or ultrastructural mitochondrial abnormalities that can impact on muscle endurance characteristics in such phenotype. To address this issue, we investigated subsarcolemmal and intermyofibrillar (IMF) mitochondrial activities, skeletal muscle redox homeostasis, and muscle fiber endurance quality in mstn-deficient mice [mstn knockout (KO)]. We report that lack of mstn induced a decrease in the coupling of IMF mitochondria respiration, with significantly higher basal oxygen consumption. No lysis of mitochondrial cristae or excessive swelling were observed in mstn KO mice compared with wild-type (WT) mice. Concerning redox status, mstn KO gastrocnemius exhibited a significant decrease in lipid peroxidation levels (−56%; P < 0.01 vs. WT) together with a significant upregulation of the antioxidant glutathione system. In contrast, superoxide dismutase and catalase activities were altered in mstn KO, gastrocnemius and soleus with a reduction of up to 80% compared with WT animals. The force production observed after contractile endurance test was significantly lower in extensor digitorum longus and soleus muscles of mstn KO mice compared with the controls (17 ± 3 and 36 ± 5% vs. 28 ± 4 and 56 ± 5%, respectively, P < 0.05). Together, these findings indicate that, besides an increased skeletal muscle mass, genetic mstn inhibition has differential effects on redox homeostasis and mitochondrial function that would have functional consequences on muscle response to endurance exercise.

2005 ◽  
Vol 22 (2) ◽  
pp. 204-212 ◽  
Author(s):  
M. Thabet ◽  
T. Miki ◽  
S. Seino ◽  
J.-M. Renaud

Although it has been suggested that the ATP-sensitive K+ (KATP) channel protects muscle against function impairment, most studies have so far given little evidence for significant perturbation in the integrity and function of skeletal muscle fibers from inactive mice that lack KATP channel activity in their cell membrane. The objective was, therefore, to test the hypothesis that KATP channel-deficient skeletal muscle fibers become damaged when mice are subjected to stress. Wild-type and KATP channel-deficient mice (Kir6.2−/− mice) were subjected to 4–5 wk of treadmill running at either 20 m/min with 0° inclination or at 24 m/min with 20° uphill inclination. Muscles of all wild-type mice and of nonexercised Kir6.2−/− mice had very few fibers with internal nuclei. After 4–5 wk of treadmill running, there was little evidence for connective tissues and mononucleated cells in Kir6.2−/− hindlimb muscles, whereas the number of fibers with internal nuclei, which appear when damaged fibers are regenerated by satellite cells, was significantly higher in Kir6.2−/− than wild-type mice. Between 5% and 25% of the total number of fibers in Kir6.2−/− extensor digitum longus, plantaris, and tibialis muscles had internal nuclei, and most of such fibers were type IIB fibers. Contrary to hindlimb muscles, diaphragms of Kir6.2−/− mice that had run at 24 m/min had few fibers with internal nuclei, but mild to severe fiber damage was observed. In conclusion, the study provides for the first time evidence 1) that the KATP channels of skeletal muscle are essential to prevent fiber damage, and thus muscle dysfunction; and 2) that the extent of fiber damage is greater and the capacity of fiber regeneration is less in Kir6.2−/− diaphragm muscles compared with hindlimb muscles.


Blood ◽  
2001 ◽  
Vol 97 (6) ◽  
pp. 1703-1711 ◽  
Author(s):  
Frederic Lluı́s ◽  
Josep Roma ◽  
Mònica Suelves ◽  
Maribel Parra ◽  
Gloria Aniorte ◽  
...  

Plasminogen activators urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) are extracellular proteases involved in various tissue remodeling processes. A requirement for uPA activity in skeletal myogenesis was recently demonstrated in vitro. The role of plasminogen activators in skeletal muscle regeneration in vivo in wild-type, uPA-deficient, and tPA-deficient mice is investigated here. Wild-type and tPA−/− mice completely repaired experimentally damaged skeletal muscle. In contrast, uPA−/− mice had a severe regeneration defect, with decreased recruitment of blood-derived monocytes to the site of injury and with persistent myotube degeneration. In addition, uPA-deficient mice accumulated fibrin in the degenerating muscle fibers; however, the defibrinogenation of uPA-deficient mice resulted in a correction of the muscle regeneration defect. A similar severe regeneration deficit with persistent fibrin deposition was also reproducible in plasminogen-deficient mice after injury, suggesting that fibrinolysis by uPA-mediated plasminogen activation plays a fundamental role in skeletal muscle regeneration. In conclusion, the uPA-plasmin system is identified as a critical component of the mammalian skeletal muscle regeneration process, possibly because it prevents intramuscular fibrin accumulation and contributes to the adequate inflammatory response after injury. These studies demonstrate the requirement of an extracellular proteolytic cascade during muscle regeneration in vivo.


1999 ◽  
Vol 277 (6) ◽  
pp. C1263-C1268 ◽  
Author(s):  
Constantinos Kyriakides ◽  
William Austen ◽  
Yong Wang ◽  
Joanne Favuzza ◽  
Lester Kobzik ◽  
...  

The relative inflammatory roles of neutrophils, selectins, and terminal complement components are investigated in this study of skeletal muscle reperfusion injury. Mice underwent 2 h of hindlimb ischemia followed by 3 h of reperfusion. The role of neutrophils was defined by immunodepletion, which reduced injury by 38%, as did anti-selectin therapy with recombinant soluble P-selectin glycoprotein ligand-immunoglobulin (Ig) fusion protein. Injury in C5-deficient and soluble complement receptor type 1-treated wild-type mice was 48% less than that of untreated wild-type animals. Injury was restored in C5-deficient mice reconstituted with wild-type serum, indicating the effector role of C5–9. Neutropenic C5-deficient animals showed additive reduction in injuries (71%), which was lower than C5-deficient neutrophil-replete mice, indicating neutrophil activity without C5a. Hindlimb histological injury was worse in ischemic wild-type and C5-deficient animals reconstituted with wild-type serum. In conclusion, the membrane attack complex and neutrophils act additively to mediate skeletal muscle reperfusion injury. Neutrophil activity is independent of C5a but is dependent on selectin-mediated adhesion.


Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 2835-2844 ◽  
Author(s):  
Mònica Suelves ◽  
Roser López-Alemany ◽  
Frederic Lluı́s ◽  
Gloria Aniorte ◽  
Erika Serrano ◽  
...  

Abstract Plasmin, the primary fibrinolytic enzyme, has a broad substrate spectrum and is implicated in biologic processes dependent upon proteolytic activity, such as tissue remodeling and cell migration. Active plasmin is generated from proteolytic cleavage of the zymogen plasminogen (Plg) by urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA). Here, we have investigated the role of plasmin in C2C12 myoblast fusion and differentiation in vitro, as well as in skeletal muscle regeneration in vivo, in wild-type and Plg-deficient mice. Wild-type mice completely repaired experimentally damaged skeletal muscle. In contrast, Plg−/− mice presented a severe regeneration defect with decreased recruitment of blood-derived monocytes and lymphocytes to the site of injury and persistent myotube degeneration. In addition, Plg-deficient mice accumulated fibrin in the degenerating muscle fibers; however, fibrinogen depletion of Plg-deficient mice resulted in a correction of the muscular regeneration defect. Because we found that uPA, but not tPA, was induced in skeletal muscle regeneration, and persistent fibrin deposition was also reproducible in uPA-deficient mice following injury, we propose that fibrinolysis by uPA-dependent plasmin activity plays a fundamental role in skeletal muscle regeneration. In summary, we identify plasmin as a critical component of the mammalian skeletal muscle regeneration process, possibly by preventing intramuscular fibrin accumulation and by contributing to the adequate inflammatory response after injury. Finally, we found that inhibition of plasmin activity with α2-antiplasmin resulted in decreased myoblast fusion and differentiation in vitro. Altogether, these studies demonstrate the requirement of plasmin during myogenesis in vitro and muscle regeneration in vivo.


Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1739
Author(s):  
Marisa L. Henry ◽  
Deborah Velez-Irizarry ◽  
Joe D. Pagan ◽  
Lorraine Sordillo ◽  
Jeff Gandy ◽  
...  

Horses have one of the highest skeletal muscle oxidative capacities amongst mammals, which, combined with a high glycolytic capacity, could perturb redox status during maximal exercise. We determined the effect of 30 d of oral coenzyme Q10 and N-acetyl-cysteine supplementation (NACQ) on muscle glutathione (GSH), cysteine, ROS, and coenzyme Q10 concentrations, and the muscle proteome, in seven maximally exercising Thoroughbred horses using a placebo and randomized cross-over design. Gluteal muscle biopsies were obtained the day before and 1 h after maximal exercise. Concentrations of GSH, cysteine, coenzyme Q10, and ROS were measured, and citrate synthase, glutathione peroxidase, and superoxide dismutase activities analyzed. GSH increased significantly 1 h post-exercise in the NACQ group (p = 0.022), whereas other antioxidant concentrations/activities were unchanged. TMT proteomic analysis revealed 40 differentially expressed proteins with NACQ out of 387 identified, including upregulation of 13 mitochondrial proteins (TCA cycle and NADPH production), 4 Z-disc proteins, and down regulation of 9 glycolytic proteins. NACQ supplementation significantly impacted muscle redox capacity after intense exercise by enhancing muscle glutathione concentrations and increasing expression of proteins involved in the uptake of glutathione into mitochondria and the NAPDH-associated reduction of oxidized glutathione, without any evident detrimental effects on performance.


2003 ◽  
Vol 12 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Hwa C. Lee ◽  
Manoj K. Patel ◽  
Dilawaar J. Mistry ◽  
Qingcai Wang ◽  
Sita Reddy ◽  
...  

DMPK is a serine/threonine kinase implicated in the human disease myotonic muscular dystrophy (DM). Skeletal muscle Na channels exhibit late reopenings in Dmpk-deficient mice and peak current density is reduced, implicating DMPK in regulation of membrane excitability. Since complete heart block and sudden cardiac death occur in the disease, we tested the hypothesis that cardiac Na channels also exhibit abnormal gating in Dmpk-deficient mice. We made whole cell and cell-attached patch clamp recordings of ventricular cardiomyocytes enzymatically isolated from wild-type, Dmpk+/−, and Dmpk−/− mice. Recordings from membrane patches containing one or a few Na channels revealed multiple Na channel reopenings occurring after the macroscopic Na current had subsided in both Dmpk+/− and Dmpk−/− muscle, but only rare reopenings in wild-type muscle (>3-fold difference, P < 0.05). This resulted in a plateau of non-inactivating Na current in Dmpk-deficient muscle. The magnitude of this plateau current was independent on the magnitude of the test potential from −40 to 0 mV and was also independent of gene dose. Macroscopic Na current density was similar in wild-type and Dmpk-deficient muscle, as was steady-state Na channel gating. Decay of macroscopic currents was slowed in Dmpk−/− muscle, but not in Dmpk+/− or wild-type muscle. Entry into, and recovery from, inactivation were similar at multiple test potentials in wild-type and Dmpk-deficient muscle. Resting membrane potential was depolarized, and action potential duration was significantly prolonged in Dmpk-deficient muscle. Thus in cardiac muscle, Dmpk deficiency results in multiple late reopenings of Na channels similar to those seen in Dmpk-deficient skeletal muscle. This is reflected in a plateau of non-inactivating macroscopic Na current and prolongation of cardiac action potentials.


1996 ◽  
Vol 91 (4) ◽  
pp. 475-481 ◽  
Author(s):  
Olav E. Rooyackers ◽  
Alexande R H. Kersten ◽  
Anton J. M. Wagenmakers

1. Recently we reported decreased activities of two mitochondrial marker enzymes (citrate synthase and cytochrome c oxidase) in skeletal muscle from a rat model of critical illness (zymosan injection). In the present study we investigated (i) whether these decreases in enzyme activity reflect a reduction in mitochondrial content and (ii) whether this potential reduction in mitochondrial content was the result of decreased mitochondrial protein synthesis rates. 2. Mitochondrial protein content was calculated from the activities of cytochrome c oxidase in whole-muscle homogenates and purified mitochondria. Synthesis rates of mitochondrial protein in vivo were studied by measuring the incorporation of [3H]phenylalanine into mitochondrial protein using the flooding dose technique. 3. Mitochondrial protein content was reduced to 54% of that measured in the pair-fed rats and to 71% of that measured in control rats fed ad libitum 2 days after the zymosan treatment The decreased mitochondrial protein content observed 2 days after zymosan challenge was preceded by a reduced rate of synthesis of mitochondrial protein 16 h after treatment. Both changes were of greater magnitude than the general muscle wasting and the decreased rate of synthesis of mixed protein observed in the zymosan-treated rats. 4. We conclude that the acute phase of critical illness in zymosan-treated rats is characterized by a substantial reduction in muscle mitochondria that is at least in part caused by a decreased rate of synthesis of mitochondrial protein. This derangement in mitochondrial protein metabolism may be related to the impaired muscle function observed during and after critical illness.


1999 ◽  
Vol 340 (3) ◽  
pp. 723-728 ◽  
Author(s):  
Ingolf GATH ◽  
Jutta EBERT ◽  
Ute GÖDTEL-ARMBRUST ◽  
Ralf ROSS ◽  
Angelika B. RESKE-KUNZ ◽  
...  

The inducible-type NO synthase (NOS II; iNOS) is constitutively expressed in slow-twitch skeletal muscle fibres of guinea-pigs [Gath, Closs, Gödtel-Armbrust, Schmitt, Nakane, Wessler and Förstermann (1996) FASEB J. 10, 1614-1620]. Here we studied the expression of NOS II in skeletal muscle of wild-type and NOS II-deficient mice and investigated the molecular basis for the membrane association of this NOS in muscle. A basal expression of NOS II mRNA and protein was detected in skeletal muscle from untreated wild-type mice; expression increased when mice were treated with bacterial lipopolysaccharide (LPS). No NOS II was found in any tissue of untreated or LPS-treated NOS II-deficient mice. Immunoprecipitation experiments were performed with homogenates of gastrocnemius muscle from untreated or LPS-treated wild-type mice. A NOS II-specific antibody precipitated caveolin 3 in all homogenates investigated, the effect being most pronounced in skeletal muscle from LPS-treated animals. Conversely, an antibody against caveolin 3 co-precipitated NOS II in muscle homogenates. Similarly, a weak co-precipitation of NOS II and caveolin 3 was seen in homogenates of untreated murine C2C12 myotubes; co-precipitation was markedly enhanced in cells stimulated with LPS/interferon γ. The association of NOS II with caveolin 3 might have implications for the regulation of contraction of, and/or glucose uptake by, slow-twitch muscle fibres.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5041
Author(s):  
Guglielmo Duranti ◽  
Mariateresa Maldini ◽  
Domenico Crognale ◽  
Katy Horner ◽  
Ivan Dimauro ◽  
...  

Moringa oleifera is a multi-purpose herbal plant with numerous health benefits. In skeletal muscle cells, Moringa oleifera leaf extract (MOLE) acts by increasing the oxidative metabolism through the SIRT1-PPARα pathway. SIRT1, besides being a critical energy sensor, is involved in the activation related to redox homeostasis of transcription factors such as the nuclear factor erythroid 2-related factor (Nrf2). The aim of the present study was to evaluate in vitro the capacity of MOLE to influence the redox status in C2C12 myotubes through the modulation of the total antioxidant capacity (TAC), glutathione levels, Nrf2 and its target gene heme oxygenase-1 (HO-1) expression, as well as enzyme activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and transferase (GST). Moreover, the impact of MOLE supplementation on lipid peroxidation and oxidative damage (i.e., TBARS and protein carbonyls) was evaluated. Our results highlight for the first time that MOLE increased not only Nrf2 and HO-1 protein levels in a dose-dependent manner, but also improved glutathione redox homeostasis and the enzyme activities of CAT, SOD, GPx and GST. Therefore, it is intriguing to speculate that MOLE supplementation could represent a valuable nutrition for the health of skeletal muscles.


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