Identification of Potential Calorie Restriction-Mimicking Yeast Mutants with Increased Mitochondrial Respiratory Chain and Nitric Oxide Levels

Calorie restriction (CR) induces a metabolic shift towards mitochondrial respiration; however, molecular mechanisms underlying CR remain unclear. Recent studies suggest that CR-induced mitochondrial activity is associated with nitric oxide (NO) production. To understand the role of mitochondria in CR, we identify and studySaccharomyces cerevisiaemutants with increased NO levels as potential CR mimics. Analysis of the top 17 mutants demonstrates a correlation between increased NO, mitochondrial respiration, and longevity. Interestingly, treating yeast with NO donors such as GSNO (S-nitrosoglutathione) is sufficient to partially mimic CR to extend lifespan. CR-increased NO is largely dependent on mitochondrial electron transport and cytochrome c oxidase (COX). Although COX normally produces NO under hypoxic conditions, CR-treated yeast cells are able to produce NO under normoxic conditions. Our results suggest that CR may derepress some hypoxic genes for mitochondrial proteins that function to promote the production of NO and the extension of lifespan.

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The Signaling Pathways in Nitric Oxide Production by Neutrophils Exposed to N-nitrosodimethylamine

Letters in Drug Design & Discovery ◽

10.2174/1570180815666180426121503 ◽

2018 ◽

Vol 16 (2) ◽

pp. 194-199

Author(s):

Wioletta Ratajczak-Wrona ◽

Ewa Jablonska

Keyword(s):

Nitric Oxide ◽

Signaling Pathways ◽

Molecular Mechanisms ◽

Polymorphonuclear Neutrophils ◽

Microbial Pathogens ◽

Human Neutrophils ◽

No Production ◽

Oxide Synthase ◽

Inducible Nitric Oxide

Background: Polymorphonuclear neutrophils (PMNs) play a crucial role in the innate immune system’s response to microbial pathogens through the release of reactive nitrogen species, including Nitric Oxide (NO). </P><P> Methods: In neutrophils, NO is produced by the inducible Nitric Oxide Synthase (iNOS), which is regulated by various signaling pathways and transcription factors. N-nitrosodimethylamine (NDMA), a potential human carcinogen, affects immune cells. NDMA plays a major part in the growing incidence of cancers. Thanks to the increasing knowledge on the toxicological role of NDMA, the environmental factors that condition the exposure to this compound, especially its precursors- nitrates arouse wide concern. Results: In this article, we present a detailed summary of the molecular mechanisms of NDMA’s effect on the iNOS-dependent NO production in human neutrophils. Conclusion: This research contributes to a more complete understanding of the mechanisms that explain the changes that occur during nonspecific cellular responses to NDMA toxicity.

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Alternative oxidase is an important player in the regulation of nitric oxide levels under normoxic and hypoxic conditions in plants

Journal of Experimental Botany ◽

10.1093/jxb/erz160 ◽

2019 ◽

Vol 70 (17) ◽

pp. 4345-4354 ◽

Cited By ~ 13

Author(s):

Aprajita Kumari ◽

Pradeep Kumar Pathak ◽

Mallesham Bulle ◽

Abir U Igamberdiev ◽

Kapuganti Jagadis Gupta

Keyword(s):

Nitric Oxide ◽

Alternative Oxidase ◽

Plant Mitochondria ◽

No Production ◽

Complex Iv ◽

Increase Energy Efficiency ◽

Hypoxic Conditions ◽

Cytochrome Pathway ◽

Important Player ◽

Elicitor Treatments

Abstract Plant mitochondria possess two different pathways for electron transport from ubiquinol: the cytochrome pathway and the alternative oxidase (AOX) pathway. The AOX pathway plays an important role in stress tolerance and is induced by various metabolites and signals. Previously, several lines of evidence indicated that the AOX pathway prevents overproduction of superoxide and other reactive oxygen species. More recent evidence suggests that AOX also plays a role in regulation of nitric oxide (NO) production and signalling. The AOX pathway is induced under low phosphate, hypoxia, pathogen infections, and elicitor treatments. The induction of AOX under aerobic conditions in response to various stresses can reduce electron transfer through complexes III and IV and thus prevents the leakage of electrons to nitrite and the subsequent accumulation of NO. Excess NO under various stresses can inhibit complex IV; thus, the AOX pathway minimizes nitrite-dependent NO synthesis that would arise from enhanced electron leakage in the cytochrome pathway. By preventing NO generation, AOX can reduce peroxynitrite formation and tyrosine nitration. In contrast to its function under normoxia, AOX has a specific role under hypoxia, where AOX can facilitate nitrite-dependent NO production. This reaction drives the phytoglobin–NO cycle to increase energy efficiency under hypoxia.

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Nitric oxide signalling: insect brains and photocytes

Biochemical Society Symposium ◽

10.1042/bss0710065 ◽

2004 ◽

Vol 71 ◽

pp. 65-83 ◽

Cited By ~ 8

Author(s):

Barry A. Trimmer ◽

June Aprille ◽

Josephine Modica-Napolitano

Keyword(s):

Nitric Oxide ◽

Central Nervous System ◽

Nervous System ◽

Nicotinic Acetylcholine Receptors ◽

Acetylcholine Receptors ◽

Bright Light ◽

Mitochondrial Activity ◽

No Production ◽

Direct Oxidation ◽

Light Production

The success of insects arises partly from extraordinary biochemical and physiological specializations. For example, most species lack glutathione peroxidase, glutathione reductase and respiratory-gas transport proteins and thus allow oxygen to diffuse directly into cells. To counter the increased potential for oxidative damage, insect tissues rely on the indirect protection of the thioredoxin reductase pathway to maintain redox homoeostasis. Such specializations must impact on the control of reactive oxygen species and free radicals such as the signalling molecule NO. This chapter focuses on NO signalling in the insect central nervous system and in the light-producing lantern of the firefly. It is shown that neural NO production is coupled to both muscarinic and nicotinic acetylcholine receptors. The NO-mediated increase in cGMP evokes changes in spike activity of neurons controlling the gut and body wall musculature. In addition, maps of NO-producing and -responsive neurons make insects useful models for establishing the range and specificity of NO's actions in the central nervous system. The firefly lantern also provides insight into the interplay of tissue anatomy and cellular biochemistry in NO signalling. In the lantern, nitric oxide synthase is expressed in tracheal end cells that are interposed between neuron terminals and photocytes. Exogenous NO can activate light production and NO scavengers block evoked flashes. NO inhibits respiration in isolated lantern mitochondria and this can be reversed by bright light. It is proposed that NO controls flashes by transiently inhibiting oxygen consumption and permitting direct oxidation of activated luciferin. It is possible that light production itself contributes to the restoration of mitochondrial activity and consequent cessation of the flash.

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Nitric oxide and superoxide transport in a cross section of the rat outer medulla. II. Reciprocal interactions and tubulovascular cross talk

AJP Renal Physiology ◽

10.1152/ajprenal.00681.2009 ◽

2010 ◽

Vol 299 (3) ◽

pp. F634-F647 ◽

Cited By ~ 11

Author(s):

Aurélie Edwards ◽

Anita T. Layton

Keyword(s):

Nitric Oxide ◽

Cross Sections ◽

Cross Talk ◽

Three Dimensional ◽

No Production ◽

Outer Medulla ◽

Nacl Transport ◽

Hypoxic Conditions ◽

Outer Stripe ◽

Main Determinants

In a companion study (Edwards A and Layton AT. Am J Physiol Renal Physiol. doi:10.1152/ajprenal.00680.2009), we developed a mathematical model of nitric oxide (NO), superoxide (O2−), and total peroxynitrite (ONOO) transport in mid-outer stripe and mid-inner stripe cross sections of the rat outer medulla (OM). We examined how the three-dimensional architecture of the rat OM, together with low medullary oxygen tension (Po2), affects the distribution of NO, O2−, and ONOO in the rat OM. In the current study, we sought to determine generation rate and permeability values that are compatible with measurements of medullary NO concentrations and to assess the importance of tubulovascular cross talk and NO-O2− interactions under physiological conditions. Our results suggest that the main determinants of NO concentrations in the rat OM are the rate of vascular and tubular NO synthesis under hypoxic conditions, and the red blood cell (RBC) permeability to NO ( PNORBC). The lower the PNORBC, the lower the amount of NO that is scavenged by hemoglobin species, and the higher the extra-erythrocyte NO concentrations. In addition, our results indicate that basal endothelial NO production acts to significantly limit NaCl reabsorption across medullary thick ascending limbs and to sustain medullary perfusion, whereas basal epithelial NO production has a smaller impact on NaCl transport and a negligible effect on vascular tone. Our model also predicts that O2− consumption by NO significantly reduces medullary O2− concentrations, but that O2− , when present at subnanomolar concentrations, has a small impact on medullary NO bioavailability.

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Prolactin activation of mammary nitric oxide synthase: molecular mechanisms

Journal of Molecular Endocrinology ◽

10.1677/jme.0.0280045 ◽

2002 ◽

Vol 28 (1) ◽

pp. 45-51 ◽

Cited By ~ 12

Author(s):

Keyword(s):

Nitric Oxide ◽

Protein Kinase ◽

Intracellular Calcium ◽

Molecular Mechanisms ◽

Mammary Epithelial Cells ◽

Calcium Ionophore ◽

Mammary Epithelial ◽

No Production ◽

2B Protein ◽

Oxide Synthase

Prolactin (PRL) is capable of stimulating both calcium and nitric oxide (NO) accumulation in mammary epithelial cells within 15min. A calcium ionophore was also able to stimulate NO levels to an extent similar to that generated by PRL. Furthermore, maximal concentrations of PRL and the ionophore were not additive, suggesting that they were both using the same pathway, i.e. calcium. Finally, the depletion of intracellular calcium completely abrogated the effect of PRL on NO production. No other pathway known to affect NO synthase (NOS) influenced the action of PRL. Specifically, manipulations of protein phosphatase 2B, protein kinase B (PKB), protein kinase C (PKC), and arginine transport did not alter the activation of NOS by PRL. Therefore, the ability of PRL to stimulate NO production at 15min can be completely explained by its ability to elevate intracellular calcium.

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Inhibition of Inducible Nitric Oxide Synthase Prevents IL-1β-Induced Mitochondrial Dysfunction in Human Chondrocytes

International Journal of Molecular Sciences ◽

10.3390/ijms22052477 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2477

Author(s):

Annett Eitner ◽

Sylvia Müller ◽

Christian König ◽

Arne Wilharm ◽

Rebecca Raab ◽

...

Keyword(s):

Nitric Oxide ◽

Mitochondrial Dysfunction ◽

Mitochondrial Function ◽

Mitochondrial Respiration ◽

Negative Impact ◽

Intracellular Camp ◽

No Production ◽

No Release ◽

Oa Chondrocytes ◽

Amp Activated Protein Kinase

Interleukin (IL)-1β is an important pro-inflammatory cytokine in the progression of osteoarthritis (OA), which impairs mitochondrial function and induces the production of nitric oxide (NO) in chondrocytes. The aim was to investigate if blockade of NO production prevents IL-1β-induced mitochondrial dysfunction in chondrocytes and whether cAMP and AMP-activated protein kinase (AMPK) affects NO production and mitochondrial function. Isolated human OA chondrocytes were stimulated with IL-1β in combination with/without forskolin, L-NIL, AMPK activator or inhibitor. The release of NO, IL-6, PGE2, MMP3, and the expression of iNOS were measured by ELISA or Western blot. Parameters of mitochondrial respiration were measured using a seahorse analyzer. IL-1β significantly induced NO release and mitochondrial dysfunction. Inhibition of iNOS by L-NIL prevented IL-1β-induced NO release and mitochondrial dysfunction but not IL-1β-induced release of IL-6, PGE2, and MMP3. Enhancement of cAMP by forskolin reduced IL-1β-induced NO release and prevented IL-1β-induced mitochondrial impairment. Activation of AMPK increased IL-1β-induced NO production and the negative impact of IL-1β on mitochondrial respiration, whereas inhibition of AMPK had the opposite effects. NO is critically involved in the IL-1β-induced impairment of mitochondrial respiration in human OA chondrocytes. Increased intracellular cAMP or inhibition of AMPK prevented both IL-1β-induced NO release and mitochondrial dysfunction.

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Atg32 dependent mitophagy sustains spermidine and nitric oxide required for heat stress tolerance in S. cerevisiae

Journal of Cell Science ◽

10.1242/jcs.253781 ◽

2021 ◽

Author(s):

Jasvinder Kaur ◽

Juliet Goldsmith ◽

Alexandra Tankka ◽

Sofía Bustamante Eguiguren ◽

Alfredo A. Gimenez ◽

...

Keyword(s):

Nitric Oxide ◽

Heat Stress ◽

Molecular Mechanisms ◽

Physiological Role ◽

No Production ◽

Polyamine Biosynthesis ◽

Adenosyl Methionine ◽

Autophagic Degradation ◽

Respiratory Growth ◽

Induced Defects

In Saccharomyces cerevisiae, the selective autophagic degradation of mitochondria, termed mitophagy, is critically regulated by the adapter protein, Atg32. Despite our knowledge about the molecular mechanisms by which Atg32 controls mitophagy, its physiological roles in yeast survival and fitness remains less clear. Here, we demonstrate a requirement for Atg32 in promoting spermidine production during respiratory growth and heat-induced mitochondrial stress. During respiratory growth, mitophagy-deficient yeast exhibit profound heat-stress induced defects in growth and viability due to impaired biosynthesis of spermidine and its biosynthetic precursor S-Adenosyl-Methionine (SAM). Moreover, spermidine production is crucial for the induction of cytoprotective nitric oxide (NO) during heat stress. Hence, the re-addition of spermidine to Atg32 mutant yeast is sufficient to both enhance NO production and restore respiratory growth during heat stress. Our findings uncover a previously unrecognized physiological role for yeast mitophagy in spermidine metabolism and illuminate new interconnections between mitophagy, polyamine biosynthesis and NO signaling.

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Intragenic repeat expansions control yeast chronological aging

10.1101/653006 ◽

2019 ◽

Cited By ~ 2

Author(s):

Benjamin P Barré ◽

Johan Hallin ◽

Jia-Xing Yue ◽

Karl Persson ◽

Ekaterina Mikhalev ◽

...

Keyword(s):

Life Span ◽

Calorie Restriction ◽

Molecular Mechanisms ◽

Tandem Repeats ◽

Repeat Expansion ◽

Yeast Cells ◽

Chronological Aging ◽

Cellular Life ◽

Chronological Life Span ◽

Repeat Expansions

ABSTRACTAging varies among individuals due to both genetics and environment but the underlying molecular mechanisms remain largely unknown. Using a highly recombinedSaccharomyces cerevisiaepopulation, we found 30 distinct Quantitative Trait Loci (QTLs) that control chronological life span (CLS) in calorie rich and calorie restricted environments, and under rapamycin exposure. Calorie restriction and rapamycin extended life span in virtually all genotypes, but through different genetic variants. We tracked the two major QTLs to massive expansions of intragenic tandem repeats in the cell wall glycoproteinsFLO11andHPF1, which caused a dramatic life span shortening. Life span impairment by N-terminalHPF1repeat expansion was partially buffered by rapamycin but not by calorie restriction. TheHPF1repeat expansion shifted yeast cells from a sedentary to a buoyant state, thereby increasing their exposure to surrounding oxygen. The higher oxygenation perturbed methionine, lipid, and purine metabolism, which likely explains the life span shortening. We conclude that fast evolving intragenic repeat expansions can fundamentally change the relationship between cells and their environment with profound effects on cellular life style and longevity.

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Metabolic reprogramming in chondrocytes to promote mitochondrial respiration reduces downstream features of osteoarthritis

10.21203/rs.3.rs-113139/v1 ◽

2020 ◽

Author(s):

Yoshifumi Ohashi ◽

Nobunori Takahashi ◽

Kenya Terabe ◽

Saho Tsuchiya ◽

Toshihisa Kojima ◽

...

Keyword(s):

Nitric Oxide ◽

Mitochondrial Respiration ◽

Culture Media ◽

Metabolic Reprogramming ◽

Cartilage Explants ◽

Mitochondrial Activity ◽

Metabolic Dysfunction ◽

Osteoarthritic Cartilage ◽

Atp Production ◽

Functional Features

Abstract Metabolic dysfunction in chondrocytes drives the pro-catabolic phenotype associated with osteoarthritic cartilage. In this study, substitution of galactose for glucose in culture media was used to promote a renewed dependence on mitochondrial respiration for ATP production. Galactose replacement alone blocked enhanced usage of the glycolysis pathway by IL1β-activated chondrocytes as detected by real-time changes in the rates of proton acidification of the medium and changes in oxygen consumption. The change in mitochondrial activity due to galactose was visualized as a rescue of mitochondrial membrane potential but not an alteration in the number of mitochondria. Galactose-replacement reversed other markers of dysfunctional mitochondrial metabolism, including blocking the production of reactive oxygen species, nitric oxide, and the synthesis of inducible nitric oxide synthase. Of more clinical relevance, galactose-substitution blocked downstream functional features associated with osteoarthritis, including enhanced levels of MMP13 mRNA, MMP13 protein, and the degradative loss of proteoglycan from intact cartilage explants. Blocking baseline and IL1β-enhanced MMP13 by galactose-replacement in human osteoarthritic chondrocyte cultures inversely paralleled increases in markers associated with mitochondrial recovery, phospho-AMPK, and PGC1α. Comparisons were made between galactose replacement and the glycolysis inhibitor 2-deoxyglucose. Targeting intermediary metabolism may provide a novel approach to osteoarthritis care.

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Nitric Oxide Synthase inhibition counteracts the stress-induced DNA methyltransferase 3b expression in the hippocampus of rats

10.1101/2020.08.06.240374 ◽

2020 ◽

Author(s):

Izaque de Sousa Maciel ◽

Amanda Juliana Sales ◽

Plinio C Casarotto ◽

Eero Castrén ◽

Caroline Biojone ◽

...

Keyword(s):

Nitric Oxide ◽

Mrna Expression ◽

Learned Helplessness ◽

Hippocampal Neurons ◽

Dna Methyltransferase ◽

Molecular Mechanisms ◽

Calcium Influx ◽

No Production ◽

Dna Methyltransferase 3B ◽

Nos Inhibitors

AbstractIt has been postulated that activation of NMDA receptors (NMDAr) and nitric oxide (NO) production in the hippocampus is involved in the behavioral consequences of stress. Stress triggers NMDAr-induced calcium influx in limbic areas, such as the hippocampus, which in turn activates neuronal NO synthase (nNOS). Inhibition of nNOS or NMDAr activity can prevent stress-induced effects in animal models, but the molecular mechanisms behind this effect are still unclear. In this study, cultured hippocampal neurons treated with NMDA or dexamethasone showed increased of DNA methyltransferase 3b (DNMT3b) mRNA expression, which was blocked by pre-treatment with nNOS inhibitor nω-propyl-L-arginine (NPA). In rats submitted to the Learned Helplessness paradigm (LH), we observed that inescapable stress increased of DNMT3b mRNA expression at 1h and 24h in the hippocampus. The NOS inhibitors 7-NI and aminoguanidine (AMG) decreased the number of escape failures in LH, and counteracted the changes in hippocampal DNMT3b mRNA induced in this behavioral paradigm. Altogether, our data suggest that NO produced in response to NMDAr activation following stress upregulates DNMT3b in the hippocampus.

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