scholarly journals ROS and hypoxia signaling regulate periodic metabolic arousal during insect dormancy to coordinate glucose, amino acid, and lipid metabolism

2020 ◽  
Vol 118 (1) ◽  
pp. e2017603118
Author(s):  
Chao Chen ◽  
Rohit Mahar ◽  
Matthew E. Merritt ◽  
David L. Denlinger ◽  
Daniel A. Hahn
Keyword(s):  
Energy Savings ◽  
Tricarboxylic Acid Cycle ◽  
Metabolic Depression ◽  
Oxygen Species ◽  
Metabolic Intermediates ◽  
Cyclic Patterns ◽  
Metabolic Suppression ◽  
Carnitine Palmitoyltransferase I ◽  
By Products ◽  
Periodic Arousal

Metabolic suppression is a hallmark of animal dormancy that promotes overall energy savings. Some diapausing insects and some mammalian hibernators have regular cyclic patterns of substantial metabolic depression alternating with periodic arousal where metabolic rates increase dramatically. Previous studies, largely in mammalian hibernators, have shown that periodic arousal is driven by an increase in aerobic mitochondrial metabolism and that many molecules related to energy metabolism fluctuate predictably across periodic arousal cycles. However, it is still not clear how these rapid metabolic shifts are regulated. We first found that diapausing flesh fly pupae primarily use anaerobic glycolysis during metabolic depression but engage in aerobic respiration through the tricarboxylic acid cycle during periodic arousal. Diapausing pupae also clear anaerobic by-products and regenerate many metabolic intermediates depleted in metabolic depression during arousal, consistent with patterns in mammalian hibernators. We found that decreased levels of reactive oxygen species (ROS) induced metabolic arousal and elevated ROS extended the duration of metabolic depression. Our data suggest ROS regulates the timing of metabolic arousal by changing the activity of two critical metabolic enzymes, pyruvate dehydrogenase and carnitine palmitoyltransferase I by modulating the levels of hypoxia inducible transcription factor (HIF) and phosphorylation of adenosine 5′-monophosphate-activated protein kinase (AMPK). Our study shows that ROS signaling regulates periodic arousal in our insect diapasue system, suggesting the possible importance ROS for regulating other types of of metabolic cycles in dormancy as well.

Progress in understanding the molecular oxygen paradox – function of mitochondrial reactive oxygen species in cell signaling

2017 ◽  
Vol 398 (11) ◽  
pp. 1209-1227 ◽  
Author(s):  
Nidhi Kuksal ◽  
Julia Chalker ◽  
Ryan J. Mailloux
Keyword(s):  
Reactive Oxygen Species ◽  
Molecular Oxygen ◽  
Reactive Oxygen ◽  
Oxygen Metabolism ◽  
Antioxidant Systems ◽  
Oxygen Species ◽  
Oxygen Paradox ◽  
Secondary Messenger ◽  
Cell Structures ◽  
By Products

AbstractThe molecular oxygen (O2) paradox was coined to describe its essential nature and toxicity. The latter characteristic of O2is associated with the formation of reactive oxygen species (ROS), which can damage structures vital for cellular function. Mammals are equipped with antioxidant systems to fend off the potentially damaging effects of ROS. However, under certain circumstances antioxidant systems can become overwhelmed leading to oxidative stress and damage. Over the past few decades, it has become evident that ROS, specifically H2O2, are integral signaling molecules complicating the previous logos that oxyradicals were unfortunate by-products of oxygen metabolism that indiscriminately damage cell structures. To avoid its potential toxicity whilst taking advantage of its signaling properties, it is vital for mitochondria to control ROS production and degradation. H2O2elimination pathways are well characterized in mitochondria. However, less is known about how H2O2production is controlled. The present review examines the importance of mitochondrial H2O2in controlling various cellular programs and emerging evidence for how production is regulated. Recently published studies showing how mitochondrial H2O2can be used as a secondary messenger will be discussed in detail. This will be followed with a description of how mitochondria use S-glutathionylation to control H2O2production.

Modulation of glucose metabolism in macrophages by products of nitric oxide synthase

1993 ◽  
Vol 264 (6) ◽  
pp. C1594-C1599 ◽  
Author(s):  
J. E. Albina ◽  
B. Mastrofrancesco
Keyword(s):  
Nitric Oxide ◽  
Glucose Metabolism ◽  
Oxidative Metabolism ◽  
Culture Media ◽  
Tricarboxylic Acid Cycle ◽  
Specific Inhibitor ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
The Impact ◽  
By Products

Nitric oxide (NO) is a product of L-arginine metabolism that suppresses cellular oxidative metabolism through the inhibition of tricarboxylic acid cycle and electron transport chain enzymes. The impact of NO synthase (NOS) activity on specific pathways of glucose metabolism in freshly harvested and overnight-cultured rat resident peritoneal macrophages, at rest and after stimulation with zymosan, was investigated using radiolabeled glucose. NOS activity was modulated through the L-arginine concentration in culture media and the use of its specific inhibitor, NG-monomethyl-L-arginine, and quantitated using radiolabeled L-arginine. Results demonstrated that NOS activity was associated with increased glucose disappearance, glycolysis, and hexose monophosphate shunt activity and, in line with the known inhibition of oxidative metabolism associated with the production of NO, with a decrease in the flux of glucose and butyrate carbon through the tricarboxylic acid cycle. In addition, the relative increase in glucose utilization that follows zymosan stimulation was enhanced by treatments that suppressed NOS activity. These results demonstrate that the characteristics of glucose metabolism by macrophages are, to a significant extent, determined by products of NOS.

scholarly journals 15 YEARS OF PARAGANGLIOMA: Metabolism and pheochromocytoma/paraganglioma

2015 ◽  
Vol 22 (4) ◽  
pp. T83-T90 ◽  
Author(s):  
Massimo Mannelli ◽  
Elena Rapizzi ◽  
Rossella Fucci ◽  
Letizia Canu ◽  
Tonino Ercolino ◽  
...  
Keyword(s):  
Reactive Oxygen Species Production ◽  
Tricarboxylic Acid Cycle ◽  
Cell Metabolism ◽  
Susceptibility Gene ◽  
Tricarboxylic Acid ◽  
Oxygen Species ◽  
Dna Hypermethylation ◽  
Subsequent Work ◽  
Acid Cycle ◽  
Species Production

The discovery ofSDHDas a pheochromocytoma/paraganglioma susceptibility gene was the prismatic event that led to all of the subsequent work highlighting the key roles played by mitochondria in the pathogenesis of these tumors and other solid cancers. Alterations in the function of tricarboxylic acid cycle enzymes can cause accumulation of intermediate substrates and subsequent changes in cell metabolism, activation of the angiogenic pathway, increased reactive oxygen species production, DNA hypermethylation, and modification of the tumor microenvironment favoring tumor growth and aggressiveness. The elucidation of these tumorigenic mechanisms should lead to novel therapeutic targets for the treatment of the most aggressive forms of pheochromocytoma/paraganglioma.

Alternative, Environmentally Acceptable Materials in Road Construction

2015 ◽  
pp. 318-348
Author(s):  
Sanja Dimter ◽  
Tatjana Rukavina ◽  
Ivana Barišić
Keyword(s):  
Sustainable Development ◽  
Natural Resources ◽  
Energy Savings ◽  
Road Construction ◽  
Environmental Conservation ◽  
Waste Materials ◽  
Construction Costs ◽  
Alternative Materials ◽  
Economic Perspectives ◽  
By Products

Environmental conservation and energy savings, as the fundamental assumptions for sustainable development, and financial savings are possible through the use of new, non-standard materials and technologies in the building and maintenance of roads. Different types of waste materials and industrial by-products may be used in road construction as an alternative to standard materials. In order to be applicable, alternative materials must meet certain engineering characteristics, show an acceptable level of execution, and be economical in comparison with traditional materials. The reasons for the use of alternative materials are many and largely outweigh the possible shortcomings. The use of alternative materials is significant from both the ecological and economic perspectives. Ecologically, the use of alternative materials means a lesser need for the exploitation of natural resources and the quantity of waste accumulated in landfills is reduced. Economically, the use of alternative materials reduces total construction costs. This chapter explores the use of alternative materials.

scholarly journals Metabolomic Dynamics Reveals Oxidative Stress in Spongy Tissue Disorder During Ripening of Mangifera indica L. Fruit

Metabolites ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 255 ◽  
Author(s):  
Pranjali Oak ◽  
Ashish Deshpande ◽  
Ashok Giri ◽  
Vidya Gupta
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Tricarboxylic Acid Cycle ◽  
Mangifera Indica ◽  
Reactive Oxygen ◽  
Spectrometric Analysis ◽  
Oxygen Species ◽  
Spongy Tissue ◽  
Mango Fruit ◽  
Alphonso Mango

Spongy tissue disorder, a mesocarp specific malady, severely affects the flavor and pulp characters of Alphonso mango fruit reducing its consumer acceptability. Here, we investigated comparative metabolomic changes that occur during ripening in healthy and spongy tissue-affected fruits using high resolution mass spectrometric analysis. During the spongy tissue formation, 46 metabolites were identified to be differentially accumulated. These putative metabolites belong to various primary and secondary metabolic pathways potentially involved in maintaining the quality of the fruit. Analysis revealed metabolic variations in tricarboxylic acid cycle and gamma amino butyric acid shunt generating reactive oxygen species, which causes stressed conditions inside the mesocarp. Further, reduced levels of antioxidants and enzymes dissipating reactive oxygen species in mesocarp deteriorate the fruit physiology. This oxidative stress all along affects the level of amino acids, sugars and enzymes responsible for flavor generation in the fruit. Our results provide metabolic insights into spongy tissue development in ripening Alphonso mango fruit.

Reactive oxygen species in cell signaling

2000 ◽  
Vol 279 (6) ◽  
pp. L1005-L1028 ◽  
Author(s):  
Victor J. Thannickal ◽  
Barry L. Fanburg
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Signal Transduction ◽  
Plasma Membrane ◽  
Growth Factors ◽  
Redox State ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Cellular Redox ◽  
By Products

Reactive oxygen species (ROS) are generated as by-products of cellular metabolism, primarily in the mitochondria. When cellular production of ROS overwhelms its antioxidant capacity, damage to cellular macromolecules such as lipids, protein, and DNA may ensue. Such a state of “oxidative stress” is thought to contribute to the pathogenesis of a number of human diseases including those of the lung. Recent studies have also implicated ROS that are generated by specialized plasma membrane oxidases in normal physiological signaling by growth factors and cytokines. In this review, we examine the evidence for ligand-induced generation of ROS, its cellular sources, and the signaling pathways that are activated. Emerging concepts on the mechanisms of signal transduction by ROS that involve alterations in cellular redox state and oxidative modifications of proteins are also discussed.

scholarly journals Reactive Oxygen Species and the Cardiovascular System

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Yannick J. H. J. Taverne ◽  
Ad J. J. C. Bogers ◽  
Dirk J. Duncker ◽  
Daphne Merkus
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Oxygen Consumption ◽  
Free Radicals ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Cellular Homeostasis ◽  
Cardiovascular Pathology ◽  
Pathological Conditions ◽  
By Products

Ever since the discovery of free radicals, many hypotheses on the deleterious actions of reactive oxygen species (ROS) have been proposed. However, increasing evidence advocates the necessity of ROS for cellular homeostasis. ROS are generated as inherent by-products of aerobic metabolism and are tightly controlled by antioxidants. Conversely, when produced in excess or when antioxidants are depleted, ROS can inflict damage to lipids, proteins, and DNA. Such a state of oxidative stress is associated with many pathological conditions and closely correlated to oxygen consumption. Although the deleterious effects of ROS can potentially be reduced by restoring the imbalance between production and clearance of ROS through administration of antioxidants (AOs), the dosage and type of AOs should be tailored to the location and nature of oxidative stress. This paper describes several pathways of ROS signaling in cellular homeostasis. Further, we review the function of ROS in cardiovascular pathology and the effects of AOs on cardiovascular outcomes with emphasis on the so-called oxidative paradox.

Energetic consequences of metabolic depression in tropical and temperate-zone lizards

1999 ◽  
Vol 47 (2) ◽  
pp. 133 ◽  
Author(s):  
Keith A. Christian ◽  
Gavin S. Bedford ◽  
Timothy J. Schultz
Keyword(s):  
Energy Savings ◽  
Environmental Parameters ◽  
Thermal Acclimation ◽  
Temperate Zone ◽  
Energy Budgets ◽  
Tropical Species ◽  
Metabolic Depression ◽  
Laboratory Studies ◽  
Conservation Of Energy ◽  
Dry Tropics

One response of ectothermic animals to periods of inactivity is inverse acclimation, or metabolic depression, which results in the conservation of energy. Most studies of metabolic depression and acclimation have involved temperate-zone species, and the information from tropical species has been largely restricted to laboratory studies that failed to demonstrate thermal acclimation of metabolism. Recently, metabolic depression has been shown in several species of reptiles from the wet-dry tropics of northern Australia during the dry season. We review existing data on the energy budgets of temperate and tropical species during periods of inactivity and make calculations of energy saved due to metabolic depression across a range of temperatures. Because tropical species experience relatively high temperatures during periods of inactivity, they have a greater potential for energy savings, any enhancement of their metabolic depression is disproportionately advantageous with respect to energy savings, and in some species metabolic depression is probably essential for survival. Thus, we would expect metabolic depression to be well developed in some tropical reptiles. The lack of thermal acclimation in laboratory studies indicates that environmental parameters other than temperature (such as food or water) may initiate metabolic depression in tropical species. Higher temperatures, however, magnify the energy savings accomplished by metabolic depression.

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