scholarly journals AKT controls protein synthesis and oxidative metabolism via combined mTORC1 and FOXO1 signalling to govern muscle physiology

2021 ◽  
Author(s):  
Natasha Jaiswal ◽  
Matthew Gavin ◽  
Emanuele Loro ◽  
Jaimarie Sostre‐Colón ◽  
Paul A. Roberson ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Oxidative Metabolism ◽  
Muscle Physiology

Ovine fetal metabolism during norepinephrine infusion

1997 ◽  
Vol 273 (2) ◽  
pp. E336-E347 ◽  
Author(s):  
J. R. Milley
Keyword(s):  
Protein Synthesis ◽  
Fetal Growth ◽  
Oxidative Metabolism ◽  
Protein Metabolism ◽  
Amino Nitrogen ◽  
Fetal Life ◽  
Norepinephrine Infusion ◽  
Response To Stress ◽  
Endogenous Substrates ◽  
Ovine Fetal

Although stress in fetal life not only increases fetal catecholamine concentration but also decreases fetal growth, there have been few studies that define the specific role of catecholamines in mediating the fetal response to stress. None, however, have investigated effects on fetal amino acid or protein metabolism, processes that should be affected during aberrant fetal growth. Therefore, hormone concentrations as well as oxygen, glucose, lactate, and amino nitrogen, leucine, and protein metabolism were measured with and without norepinephrine infusion in fetuses of eight pregnant ewes (118-125 days of gestation). Transumbilical uptake of oxygen increased during norepinephrine infusion, whereas uptake of glucose remained constant and that of lactate and amino acids fell. The proportion of fetal oxidative metabolism that could be supported by transplacental uptake of exogenous substrates was < 1, indicating that endogenous substrates were used to maintain fetal oxidative metabolism and therefore that fetal growth was diminished. Both fetal leucine uptake and oxidation decreased during norepinephrine infusion, as did fetal protein synthesis and proteolysis. Fetal protein synthesis fell more than proteolysis, however. Consequently, fetal protein accretion, a variable closely related to fetal growth, also fell. Thus the effects of norepinephrine infusion in fetuses suggest that fetal catecholamines play an important role not only in altering fetal metabolism but also in regulating fetal growth.

scholarly journals Repeated eccentric contractions positively regulate muscle oxidative metabolism and protein synthesis during cancer cachexia in mice

2020 ◽  
Vol 128 (6) ◽  
pp. 1666-1676 ◽  
Author(s):  
Justin P. Hardee ◽  
Dennis K. Fix ◽  
Ho-Jin Koh ◽  
Xuewen Wang ◽  
Edie C. Goldsmith ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Oxidative Metabolism ◽  
Cancer Cachexia ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Eccentric Contraction ◽  
Oxidative Capacity ◽  
Preclinical Model ◽  
Metabolic Plasticity ◽  
Mitochondrial Homeostasis

Cancer-induced muscle wasting is accompanied by disruptions to muscle oxidative metabolism and protein turnover regulation, whereas exercise is a potent stimulator of muscle protein synthesis and mitochondrial homeostasis. In a preclinical model of cancer cachexia, we report that cachectic muscle retains anabolic and metabolic plasticity to repeated eccentric contraction bouts despite an overall systemic wasting environment. The attenuation of muscle atrophy is linked to improved oxidative capacity and protein synthesis during cancer cachexia progression.

scholarly journals Myocardial oxidative metabolism and protein synthesis during mechanical circulatory support by extracorporeal membrane oxygenation

2013 ◽  
Vol 304 (3) ◽  
pp. H406-H414 ◽  
Author(s):  
Colleen M. O′Kelly Priddy ◽  
Masaki Kajimoto ◽  
Dolena R. Ledee ◽  
Bertrand Bouchard ◽  
Nancy Isern ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Extracorporeal Membrane Oxygenation ◽  
Oxidative Metabolism ◽  
Mechanical Circulatory Support ◽  
Gas Chromatography Mass Spectrometry ◽  
Circulatory Support ◽  
Swine Model ◽  
Protein Loss ◽  
Metabolic Disturbances ◽  
Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) provides essential mechanical circulatory support necessary for survival in infants and children with acute cardiac decompensation. However, ECMO also causes metabolic disturbances, which contribute to total body wasting and protein loss. Cardiac stunning can also occur, which prevents ECMO weaning, and contributes to high mortality. The heart may specifically undergo metabolic impairments, which influence functional recovery. We tested the hypothesis that ECMO alters oxidative metabolism and protein synthesis. We focused on the amino acid leucine and integration with myocardial protein synthesis. We used a translational immature swine model in which we assessed in heart 1) the fractional contribution of leucine (FcLeucine) and pyruvate to mitochondrial acetyl-CoA formation by nuclear magnetic resonance and 2) global protein fractional synthesis (FSR) by gas chromatography-mass spectrometry. Immature mixed breed Yorkshire male piglets ( n = 22) were divided into four groups based on loading status (8 h of normal circulation or ECMO) and intracoronary infusion [13C6,15N]-L-leucine (3.7 mM) alone or with [2-13C]-pyruvate (7.4 mM). ECMO decreased pulse pressure and correspondingly lowered myocardial oxygen consumption (∼40%, n = 5), indicating decreased overall mitochondrial oxidative metabolism. However, FcLeucine was maintained and myocardial protein FSR was marginally increased. Pyruvate addition decreased tissue leucine enrichment, FcLeucine, and Fc for endogenous substrates as well as protein FSR. The heart under ECMO shows reduced oxidative metabolism of substrates, including amino acids, while maintaining 1) metabolic flexibility indicated by ability to respond to pyruvate and 2) a normal or increased capacity for global protein synthesis.

CORTISOLWIRKUNGEN AUF DEN PROTEINUND ENERGIESTOFFWECHSEL IN DER PERIPHERIE

1968 ◽  
Vol 59 (2) ◽  
pp. 193-202
Author(s):  
H. Kröner ◽  
W. Staib
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Energy Consumption ◽  
Connective Tissue ◽  
Oxidative Metabolism ◽  
The Other ◽  
Other Hand ◽  
Inhibition Of Protein Synthesis ◽  
Short Time ◽  
Rna And Dna

ABSTRACT By measuring protein, RNA and DNA in skeletal muscle and spleen we were unable to demonstrate an enhanced catabolism due to cortisol. On the other hand we could demonstrate a reduced anabolism by diminished incorporation of 14C labelled leucin in protein of muscle, spleen and skin. Simultaneously an increase of ATP and an equivalent decrease of ADP were found in connective tissue, which were regarded as a consequence of reduced energy consumption. In skeletal muscle a decrease of energy consumption due to cortisol was only indirect demonstrable by reduced glycolysis when oxidative metabolism was eliminated for a short time. It seems obvious, that inhibition of protein synthesis causes the diminished energy consumption.

Mechanosensitive pathways controlling translation regulatory processes in skeletal muscle and implications for adaptation

2019 ◽  
Vol 127 (2) ◽  
pp. 608-618 ◽  
Author(s):  
Tyler J. Kirby
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Protein Metabolism ◽  
Mechanical Load ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Muscle Physiology ◽  
Translation Efficiency ◽  
Ribosomal Biogenesis ◽  
Mechanical Signals

The ability of myofibers to sense and respond appropriately to mechanical signals is one of the primary determinants of the skeletal muscle phenotype. In response to a change in mechanical load, muscle cells alter their protein metabolism, primarily through the regulation of protein synthesis rate. Protein synthesis rates are determined by both translation efficiency and translational capacity within the muscle. Translational capacity is strongly determined by the ribosome content of the muscle; thus the regulation of ribosomal biogenesis by mechanical inputs has been an area of recent interest. Despite the clear association between mechanical signals and changes in protein metabolism, the molecular pathways that link these events are still not fully elucidated. This review focuses on recent studies looking at how mechanosignaling impacts translational events. The role of impaired mechanotransduction in aging is discussed, as is the connection between age-dependent signaling defects and compromised ribosomal biogenesis during mechanical overload. Finally, emerging evidence suggests that the nucleus can act as a mechanosensitive element and that this mode of mechanotransduction may have an important role in skeletal muscle physiology and adaptation.

scholarly journals Mitochondrial Alterations (Inhibition of Mitochondrial Protein Expression, Oxidative Metabolism, and Ultrastructure) Induced by Linezolid and Tedizolid at Clinically Relevant Concentrations in Cultured Human HL-60 Promyelocytes and THP-1 Monocytes

2017 ◽  
Vol 62 (3) ◽  
Author(s):  
Tamara V. Milosevic ◽  
Valéry L. Payen ◽  
Pierre Sonveaux ◽  
Giulio G. Muccioli ◽  
Paul M. Tulkens ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Oxidative Metabolism ◽  
Oxidase Activity ◽  
Potent Inhibitor ◽  
Mitochondrial Protein ◽  
Mitochondrial Protein Synthesis ◽  
Once Daily ◽  
Content Type ◽  
Mitochondrial Alterations ◽  
Mitochondrial Oxidative Metabolism

ABSTRACTLinezolid, the first clinically available oxazolidinone antibiotic, causes potentially severe toxicities (myelosuppression, lactic acidosis, and neuropathies) ascribed to impairment of mitochondrial protein synthesis and consecutive mitochondrial dysfunction. Tedizolid, a newly approved oxazolidinone, shows an enhanced activity compared to linezolid but is also a more potent inhibitor of mitochondrial protein synthesis. We compared linezolid and tedizolid for (i) inhibition of the expression of subunit I of cytochromec-oxidase (CYTox I; Western blot analysis), (ii) cytochromec-oxidase activity (biochemical assay), (iii) mitochondrial oxidative metabolism (Seahorse technology), and (iv) alteration of mitochondrial ultrastructure (electron microscopy) using HL-60 promyelocytes and THP-1 monocytes exposed to microbiologically (multiples of modal MIC againstStaphylococcus aureus) and therapeutically (Cmin−Cmax) pertinent concentrations. Both drugs caused a rapid and complete (48 to 72 h) inhibition of CYTox I expression, cytochromec-oxidase activity, and spare respiratory capacity, with conspicuous swelling of the mitochondrial matrix and loss of their cristae. Globally, tedizolid was a more potent inhibitor than linezolid. For both drugs, all effects were quickly (48 to 72 h) and fully reversible upon drug withdrawal. Using an alternation of exposure to and withdrawal from drug mimicking their approved schedule of administration (twice daily and once daily [qD] for linezolid and tedizolid, respectively), only partial inhibition of CYTox I expression was noted for up to 96 h. Thus, rapid reversal of toxic effects upon discontinuous administration may mitigate oxazolidinone toxicity. Since tedizolid is given qD, this may help to explain its reported lower preclinical and clinical toxicity.

scholarly journals Linking Cancer Cachexia-Induced Anabolic Resistance to Skeletal Muscle Oxidative Metabolism

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Justin P. Hardee ◽  
Ryan N. Montalvo ◽  
James A. Carson
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Oxidative Metabolism ◽  
Cancer Cachexia ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Primary Objective ◽  
Anabolic Resistance ◽  
Metabolism Regulation ◽  
Wasting Syndrome

Cancer cachexia, a wasting syndrome characterized by skeletal muscle depletion, contributes to increased patient morbidity and mortality. While the intricate balance between protein synthesis and breakdown regulates skeletal muscle mass, the suppression of basal protein synthesis may not account for the severe wasting induced by cancer. Therefore, recent research has shifted to the regulation of “anabolic resistance,” which is the impaired ability of nutrition and exercise to stimulate protein synthesis. Emerging evidence suggests that oxidative metabolism can regulate both basal and induced muscle protein synthesis. While disrupted protein turnover and oxidative metabolism in cachectic muscle have been examined independently, evidence suggests a linkage between these processes for the regulation of cancer-induced wasting. The primary objective of this review is to highlight the connection between dysfunctional oxidative metabolism and cancer-induced anabolic resistance in skeletal muscle. First, we review oxidative metabolism regulation of muscle protein synthesis. Second, we describe cancer-induced alterations in the response to an anabolic stimulus. Finally, we review a role for exercise to inhibit cancer-induced anabolic suppression and mitochondrial dysfunction.

Homochirality as the Signature of Extra-Terrestrial Life

1997 ◽  
Vol 161 ◽  
pp. 505-510
Author(s):  
Alexandra J. MacDermott ◽  
Laurence D. Barron ◽  
Andrè Brack ◽  
Thomas Buhse ◽  
John R. Cronin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Optical Rotation ◽  
Physical Origin ◽  
Natural Choice ◽  
Rosetta Mission ◽  
Terrestrial Life ◽  
Subsurface Layers ◽  
Solar System Bodies ◽  
Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

Tobacco Mosaic Virus-Infected Tissue

1985 ◽  
Vol 43 ◽  
pp. 510-511
Author(s):  
Egbert W. Henry
Keyword(s):  
Nicotiana Tabacum ◽  
Tobacco Mosaic Virus ◽  
Chlorogenic Acid ◽  
Mosaic Virus ◽  
Host Resistance ◽  
Oxidative Metabolism ◽  
Leaf Tissue ◽  
Vein Clearing ◽  
Basal Septum ◽  
Concentration Levels

Tobacco mosaic virus (TMV) infection has been studied in several investigations of Nicotiana tabacum leaf tissue. Earlier studies have suggested that TMV infection does not have precise infective selectivity vs. specific types of tissues. Also, such tissue conditions as vein banding, vein clearing, liquification and suberization may result from causes other than direct TMV infection. At the present time, it is thought that the plasmodesmata, ectodesmata and perhaps the plasmodesmata of the basal septum may represent the actual or more precise sites of TMV infection.TMV infection has been implicated in elevated levels of oxidative metabolism; also, TMV infection may have a major role in host resistance vs. concentration levels of phenolic-type enzymes. Therefore, enzymes such as polyphenol oxidase, peroxidase and phenylalamine ammonia-lyase may show an increase in activity in response to TMV infection. It has been reported that TMV infection may cause a decrease in o-dihydric phenols (chlorogenic acid) in some tissues.

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