scholarly journals Skeletal Muscle Na,K-ATPase as a Target for Circulating Ouabain

2020 ◽  
Vol 21 (8) ◽  
pp. 2875 ◽  
Author(s):  
Violetta V. Kravtsova ◽  
Elena V. Bouzinova ◽  
Vladimir V. Matchkov ◽  
Igor I. Krivoi
Keyword(s):  
Skeletal Muscle ◽  
Diaphragm Muscle ◽  
Hindlimb Suspension ◽  
Resting Potential ◽  
Human Red Blood Cells ◽  
Central Nervous Systems ◽  
Health And Disease ◽  
Specific Increase ◽  
20 Nm

While the role of circulating ouabain-like compounds in the cardiovascular and central nervous systems, kidney and other tissues in health and disease is well documented, little is known about its effects in skeletal muscle. In this study, rats were intraperitoneally injected with ouabain (0.1–10 µg/kg for 4 days) alone or with subsequent injections of lipopolysaccharide (1 mg/kg). Some rats were also subjected to disuse for 6 h by hindlimb suspension. In the diaphragm muscle, chronic ouabain (1 µg/kg) hyperpolarized resting potential of extrajunctional membrane due to specific increase in electrogenic transport activity of the α2 Na,K-ATPase isozyme and without changes in α1 and α2 Na,K-ATPase protein content. Ouabain (10–20 nM), acutely applied to isolated intact diaphragm muscle from not injected rats, hyperpolarized the membrane to a similar extent. Chronic ouabain administration prevented lipopolysaccharide-induced (diaphragm muscle) or disuse-induced (soleus muscle) depolarization of the extrajunctional membrane. No stimulation of the α1 Na,K-ATPase activity in human red blood cells, purified lamb kidney and Torpedo membrane preparations by low ouabain concentrations was observed. Our results suggest that skeletal muscle electrogenesis is subjected to regulation by circulating ouabain via the α2 Na,K-ATPase isozyme that could be important for adaptation of this tissue to functional impairment.

scholarly journals Chronic Ouabain Prevents Na,K-ATPase Dysfunction and Targets AMPK and IL-6 in Disused Rat Soleus Muscle

2021 ◽  
Vol 22 (8) ◽  
pp. 3920
Author(s):  
Violetta V. Kravtsova ◽  
Inna I. Paramonova ◽  
Natalia A. Vilchinskaya ◽  
Maria V. Tishkova ◽  
Vladimir V. Matchkov ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Single Injection ◽  
Chronic Administration ◽  
Motor Dysfunction ◽  
Hindlimb Suspension ◽  
Muscle Disuse ◽  
Rat Soleus Muscle ◽  
Amp Activated Protein Kinase ◽  
Specific Ligand

Sustained sarcolemma depolarization due to loss of the Na,K-ATPase function is characteristic for skeletal muscle motor dysfunction. Ouabain, a specific ligand of the Na,K-ATPase, has a circulating endogenous analogue. We hypothesized that the Na,K-ATPase targeted by the elevated level of circulating ouabain modulates skeletal muscle electrogenesis and prevents its disuse-induced disturbances. Isolated soleus muscles from rats intraperitoneally injected with ouabain alone or subsequently exposed to muscle disuse by 6-h hindlimb suspension (HS) were studied. Conventional electrophysiology, Western blotting, and confocal microscopy with cytochemistry were used. Acutely applied 10 nM ouabain hyperpolarized the membrane. However, a single injection of ouabain (1 µg/kg) prior HS was unable to prevent the HS-induced membrane depolarization. Chronic administration of ouabain for four days did not change the α1 and α2 Na,K-ATPase protein content, however it partially prevented the HS-induced loss of the Na,K-ATPase electrogenic activity and sarcolemma depolarization. These changes were associated with increased phosphorylation levels of AMP-activated protein kinase (AMPK), its substrate acetyl-CoA carboxylase and p70 protein, accompanied with increased mRNA expression of interleikin-6 (IL-6) and IL-6 receptor. Considering the role of AMPK in regulation of the Na,K-ATPase, we suggest an IL-6/AMPK contribution to prevent the effects of chronic ouabain under skeletal muscle disuse.

scholarly journals Differences in the Role of HDACs 4 and 5 in the Modulation of Processes Regulating MAFbx and MuRF1 Expression during Muscle Unloading

2020 ◽  
Vol 21 (13) ◽  
pp. 4815 ◽  
Author(s):  
Ekaterina P. Mochalova ◽  
Svetlana P. Belova ◽  
Tatiana Y. Kostrominova ◽  
Boris S. Shenkman ◽  
Tatiana L. Nemirovskaya
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Histone Deacetylases ◽  
Wistar Rats ◽  
Hindlimb Suspension ◽  
Skeletal Muscle Atrophy ◽  
E3 Ligases ◽  
Male Wistar Rats ◽  
Muscle Unloading

Unloading leads to skeletal muscle atrophy via the upregulation of MuRF-1 and MAFbx E3-ligases expression. Reportedly, histone deacetylases (HDACs) 4 and 5 may regulate the expression of MuRF1 and MAFbx. To examine the HDAC-dependent mechanisms involved in the control of E3-ubiquitin ligases expression at the early stages of muscle unloading we used HDACs 4 and 5 inhibitor LMK-235 and HDAC 4 inhibitor Tasqinimod (Tq). Male Wistar rats were divided into four groups (eight rats per group): nontreated control (C), three days of unloading/hindlimb suspension (HS) and three days HS with HDACs inhibitor LMK-235 (HSLMK) or Tq (HSTq). Treatment with LMK-235 diminished unloading-induced of MAFbx, myogenin (MYOG), ubiquitin and calpain-1 mRNA expression (p < 0.05). Tq administration had no effect on the expression of E3-ligases. The mRNA expression of MuRF1 and MAFbx was significantly increased in both HS and HSTq groups (1.5 and 4.0 folds, respectively; p < 0.05) when compared with the C group. It is concluded that during three days of muscle unloading: (1) the HDACs 4 and 5 participate in the regulation of MAFbx expression as well as the expression of MYOG, ubiquitin and calpain-1; (2) the inhibition of HDAC 4 has no effect on MAFbx expression. Therefore, HDAC 5 is perhaps more important for the regulation of MAFbx expression than HDAC 4.

The Concept of Cotransmission: Focus on ATP as a Cotransmitter and its Significance in Health and Disease

2014 ◽  
Vol 22 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Geoffrey Burnstock
Keyword(s):  
Sympathetic Nerves ◽  
Purinergic Signalling ◽  
Release Of Noradrenaline ◽  
Spontaneously Hypertensive ◽  
Parasympathetic Nerves ◽  
Sympathetic Pain ◽  
Central Nervous Systems ◽  
Health And Disease ◽  
Nerve Release

The concept of cotransmission, including sympathetic nerve release of noradrenaline and ATP, was formalised in 1976, which challenged the accepted view known as ‘Dale's Principle’ that one nerve released only one transmitter. ATP was also shown to be a cotransmitter with acetylcholine in parasympathetic nerves supplying the urinary bladder and as a cotransmitter with nitric oxide in non-adrenergic, non-cholinergic inhibitory nerves supplying the intestine. It is now recognised that ATP is a cotransmitter in most, if not all, nerves in the peripheral and central nervous systems. The physiological significance of cotransmission will be considered. In pathophysiology, the role of ATP as a cotransmitter appears to increase as shown, for example, in the parasympathetic nerves supplying the diseased human bladder and in sympathetic nerves in spontaneously hypertensive rats. ATP is likely to be involved in sympathetic pain, causalgia and reflex sympathetic dystrophy. Purinergic signalling also appears to be enhanced in inflammatory and stress conditions.

scholarly journals Calcineurin plays a modulatory role in loading-induced regulation of type I myosin heavy chain gene expression in slow skeletal muscle

2009 ◽  
Vol 297 (4) ◽  
pp. R1037-R1048 ◽  
Author(s):  
Clay E. Pandorf ◽  
Weihua H. Jiang ◽  
Anqi X. Qin ◽  
Paul W. Bodell ◽  
Kenneth M. Baldwin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Fiber Type ◽  
Hindlimb Suspension ◽  
Chain Gene ◽  
Type I ◽  
Thyroid State

The role of calcineurin (Cn) in skeletal muscle fiber-type expression has been a subject of great interest because of reports indicating that it controls the slow muscle phenotype. To delineate the role of Cn in phenotype remodeling, particularly its role in driving expression of the type I myosin heavy chain (MHC) gene, we used a novel strategy whereby a profound transition from fast to slow fiber type is induced and examined in the absence and presence of cyclosporin A (CsA), a Cn inhibitor. To induce the fast-to-slow transition, we first subjected rats to 7 days of hindlimb suspension (HS) + thyroid hormone [triiodothyronine (T3)] to suppress nearly all expression of type I MHC mRNA in the soleus muscle. HS + T3 was then withdrawn, and rats resumed normal ambulation and thyroid state, during which vehicle or CsA (30 mg·kg−1·day−1) was administered for 7 or 14 days. The findings demonstrate that, despite significant inhibition of Cn, pre-mRNA, mRNA, and protein abundance of type I MHC increased markedly during reloading relative to HS + T3 ( P < 0.05). Type I MHC expression was, however, attenuated by CsA compared with vehicle treatment. In addition, type IIa and IIx MHC pre-mRNA, mRNA, and relative protein levels were increased in Cn-treated compared with vehicle-treated rats. These findings indicate that Cn has a modulatory role in MHC transcription, rather than a role as a primary regulator of slow MHC gene expression.

scholarly journals Role of Pannexin 1 ATP-Permeable Channels in the Regulation of Signaling Pathways during Skeletal Muscle Unloading

2021 ◽  
Vol 22 (19) ◽  
pp. 10444
Author(s):  
Ksenia A. Zaripova ◽  
Ekaterina P. Kalashnikova ◽  
Svetlana P. Belova ◽  
Tatiana Y. Kostrominova ◽  
Boris S. Shenkman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Signaling Pathways ◽  
Protein Translation ◽  
Hindlimb Suspension ◽  
E3 Ligases ◽  
Permeable Channel ◽  
Pannexin 1 ◽  
Muscle Unloading

Skeletal muscle unloading results in atrophy. We hypothesized that pannexin 1 ATP-permeable channel (PANX1) is involved in the response of muscle to unloading. We tested this hypothesis by blocking PANX1, which regulates efflux of ATP from the cytoplasm. Rats were divided into six groups (eight rats each): non-treated control for 1 and 3 days of the experiments (1C and 3C, respectively), 1 and 3 days of hindlimb suspension (HS) with placebo (1H and 3H, respectively), and 1 and 3 days of HS with PANX1 inhibitor probenecid (PRB; 1HP and 3HP, respectively). When compared with 3C group there was a significant increase in ATP in soleus muscle of 3H and 3HP groups (32 and 51%, respectively, p < 0.05). When compared with 3H group, 3HP group had: (1) lower mRNA expression of E3 ligases MuRF1 and MAFbx (by 50 and 38% respectively, p < 0.05) and MYOG (by 34%, p < 0.05); (2) higher phosphorylation of p70S6k and p90RSK (by 51 and 35% respectively, p < 0.05); (3) lower levels of phosphorylated eEF2 (by 157%, p < 0.05); (4) higher level of phosphorylated GSK3β (by 189%, p < 0.05). In conclusion, PANX1 ATP-permeable channels are involved in the regulation of muscle atrophic processes by modulating expression of E3 ligases, and protein translation and elongation processes during unloading.

scholarly journals Muscling in on mitochondrial sexual dimorphism; role of mitochondrial dimorphism in skeletal muscle health and disease

2017 ◽  
Vol 131 (15) ◽  
pp. 1919-1922 ◽  
Author(s):  
Gareth A. Nye ◽  
Giorgos K. Sakellariou ◽  
Hans Degens ◽  
Adam P. Lightfoot
Keyword(s):  
Skeletal Muscle ◽  
Sexual Dimorphism ◽  
Mitochondrial Function ◽  
Recent Article ◽  
Cellular Processes ◽  
Wide Range ◽  
Health And Disease ◽  
Muscle Health ◽  
The Impact

Mitochondria are no longer solely regarded as the cellular powerhouse; instead, they are now implicated in mediating a wide-range of cellular processes, in the context of health and disease. A recent article in Clinical Science, Ventura-Clapier et al. highlights the role of sexual dimorphism in mitochondrial function in health and disease. However, we feel the authors have overlooked arguably one of the most mitochondria-rich organs in skeletal muscle. Many studies have demonstrated that mitochondria have a central role in mediating the pathogenesis of myopathologies. However, the impact of sexual dimorphism in this context is less clear, with several studies reporting conflicting observations. For instance in ageing studies, a rodent model reported female muscles have higher antioxidant capacity compared with males; in contrast, human studies demonstrate no sex difference in mitochondrial bioenergetics and oxidative damage. These divergent observations highlight the importance of considering models and methods used to examine mitochondrial function, when interpreting these data. The use of either isolated or intact mitochondrial preparations in many studies appears likely to be a source of discord, when comparing many studies. Overall, it is now clear that more research is needed to determine if sexual dimorphism is a contributing factor in the development of myopathologies.

scholarly journals The Impact of Purinergic System Enzymes on Noncommunicable, Neurological, and Degenerative Diseases

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Margarete Dulce Bagatini ◽  
Alessandra Antunes dos Santos ◽  
Andréia Machado Cardoso ◽  
Aline Mânica ◽  
Cristina Ruedell Reschke ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Purinergic Signaling ◽  
P2y Receptors ◽  
Degenerative Diseases ◽  
Limited Effectiveness ◽  
Central Nervous Systems ◽  
Health And Disease ◽  
The Impact

Evidences show that purinergic signaling is involved in processes associated with health and disease, including noncommunicable, neurological, and degenerative diseases. These diseases strike from children to elderly and are generally characterized by progressive deterioration of cells, eventually leading to tissue or organ degeneration. These pathological conditions can be associated with disturbance in the signaling mediated by nucleotides and nucleosides of adenine, in expression or activity of extracellular ectonucleotidases and in activation of P2X and P2Y receptors. Among the best known of these diseases are atherosclerosis, hypertension, cancer, epilepsy, Alzheimer’s disease (AD), Parkinson’s disease (PD), and multiple sclerosis (MS). The currently available treatments present limited effectiveness and are mostly palliative. This review aims to present the role of purinergic signaling highlighting the ectonucleotidases E-NTPDase, E-NPP, E-5′-nucleotidase, and adenosine deaminase in noncommunicable, neurological, and degenerative diseases associated with the cardiovascular and central nervous systems and cancer. In conclusion, changes in the activity of ectonucleotidases were verified in all reviewed diseases. Although the role of ectonucleotidases still remains to be further investigated, evidences reviewed here can contribute to a better understanding of the molecular mechanisms of highly complex diseases, which majorly impact on patients’ quality of life.

scholarly journals Measurement of nitrate and nitrite in biopsy-sized muscle samples using HPLC

2018 ◽  
Vol 125 (5) ◽  
pp. 1475-1481 ◽  
Author(s):  
Ashley D. Troutman ◽  
Edgar J. Gallardo ◽  
Mary Beth Brown ◽  
Andrew R. Coggan
Keyword(s):  
Skeletal Muscle ◽  
Whole Body ◽  
Oxidoreductase Activity ◽  
Bead Beating ◽  
Health And Disease ◽  
Text Content ◽  
Nitrate And Nitrite ◽  
Triton X ◽  
Mechanical Homogenization

Studies of rats have indicated that skeletal muscle plays a central role in whole-body nitrate ([Formula: see text])/nitrite ([Formula: see text])/nitric oxide (NO) metabolism. Extending these results to humans, however, is challenging due to the small size of needle biopsy samples. We therefore developed a method to precisely and accurately quantify [Formula: see text] and [Formula: see text] in biopsy-sized muscle samples. [Formula: see text] and [Formula: see text] were extracted from rat soleus samples using methanol combined with mechanical homogenization + ultrasound, bead beating, pulverization at liquid N2temperature or pulverization + 0.5% Triton X-100. After centrifugation to remove proteins, [Formula: see text] and [Formula: see text] were measured using HPLC. Mechanical homogenization + ultrasound resulted in the lowest [Formula: see text] content (62 ± 20 pmol/mg), with high variability [coefficient of variation (CV) >50%] across samples from the same muscle. The [Formula: see text]/[Formula: see text] ratio (0.019 ± 0.006) was also elevated, suggestive of [Formula: see text] reduction during tissue processing. Bead beating or pulverization yielded lower [Formula: see text] and slightly higher [Formula: see text] levels, but reproducibility was still poor. Pulverization + 0.5% Triton X-100 provided the highest [Formula: see text] content (124 ± 12 pmol/mg) and lowest [Formula: see text]/[Formula: see text] ratio (0.008 ± 0.001), with the least variability between duplicate samples (CV ~15%). These values are consistent with literature data from larger rat muscle samples analyzed using chemiluminescence. Samples were stable for at least 5 wk at −80°C, provided residual xanthine oxidoreductase activity was blocked using 0.1 mmol/l oxypurinol. We have developed a method capable of measuring [Formula: see text] and [Formula: see text] in <1 mg of muscle. This method should prove highly useful in investigating the role of skeletal muscle in [Formula: see text]/[Formula: see text]/NO metabolism in human health and disease.NEW & NOTEWORTHY Measurement of nitrate and especially nitrite in small, i.e., biopsy-sized, muscle samples is analytically challenging. We have developed a precise, accurate, and convenient method for doing so using an affordable commercial HPLC system.

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