scholarly journals The Chemical Interplay between Nitric Oxide and Mitochondrial CytochromecOxidase: Reactions, Effectors and Pathophysiology

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Paolo Sarti ◽  
Elena Forte ◽  
Alessandro Giuffrè ◽  
Daniela Mastronicola ◽  
Maria Chiara Magnifico ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Complex I ◽  
Culture Conditions ◽  
The Other ◽  
Reaction Pathways ◽  
No Production ◽  
Complex Iv ◽  
Atp Production ◽  
Cell Culture Conditions ◽  
Nitrosyl Derivative

Nitric oxide (NO) reacts with Complex I and cytochromecoxidase (CcOX, Complex IV), inducing detrimental or cytoprotective effects. Two alternative reaction pathways (PWs) have been described whereby NO reacts with CcOX, producing either a relatively labile nitrite-bound derivative (CcOX-NO2 −, PW1) or a more stable nitrosyl-derivative (CcOX-NO, PW2). The two derivatives are both inhibited, displaying different persistency and O2competitiveness. In the mitochondrion, during turnover with O2, one pathway prevails over the other one depending on NO, cytochromec2+and O2concentration. High cytochromec2+, and low O2proved to be crucial in favoring CcOX nitrosylation, whereas under-standardcell-culture conditions formation of the nitrite derivative prevails. All together, these findings suggest that NO can modulate physiologically the mitochondrial respiratory/OXPHOS efficiency, eventually being converted to nitrite by CcOX, without cell detrimental effects. It is worthy to point out that nitrite, far from being a simple oxidation byproduct, represents a source of NO particularly important in view of the NO cell homeostasis, the NO production depends on the NO synthases whose activity is controlled by different stimuli/effectors; relevant to its bioavailability, NO is also produced by recycling cell/body nitrite. Bioenergetic parameters, such as mitochondrialΔΨ, lactate, and ATP production, have been assayed in several cell lines, in the presence of endogenous or exogenous NO and the evidence collected suggests a crucial interplay between CcOX and NO with important energetic implications.

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

2019 ◽  
Vol 70 (17) ◽  
pp. 4345-4354 ◽  
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.

scholarly journals Salidroside Stimulates Mitochondrial Biogenesis and Protects against H2O2-Induced Endothelial Dysfunction

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Shasha Xing ◽  
Xiaoyan Yang ◽  
Wenjing Li ◽  
Fang Bian ◽  
Dan Wu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Transcription Factor ◽  
Endothelial Dysfunction ◽  
Mitochondrial Biogenesis ◽  
Umbilical Vein ◽  
Adenosine Monophosphate ◽  
No Production ◽  
Peroxisome Proliferator ◽  
Atp Production

Salidroside (SAL) is an active component ofRhodiola roseawith documented antioxidative properties. The purpose of this study is to explore the mechanism of the protective effect of SAL on hydrogen peroxide- (H2O2-) induced endothelial dysfunction. Pretreatment of the human umbilical vein endothelial cells (HUVECs) with SAL significantly reduced the cytotoxicity brought by H2O2. Functional studies on the rat aortas found that SAL rescued the endothelium-dependent relaxation and reduced superoxide anion (O2∙-) production induced by H2O2. Meanwhile, SAL pretreatment inhibited H2O2-induced nitric oxide (NO) production. The underlying mechanisms involve the inhibition of H2O2-induced activation of endothelial nitric oxide synthase (eNOS), adenosine monophosphate-activated protein kinase (AMPK), and Akt, as well as the redox sensitive transcription factor, NF-kappa B (NF-κB). SAL also increased mitochondrial mass and upregulated the mitochondrial biogenesis factors, peroxisome proliferator-activated receptor gamma-coactivator-1alpha (PGC-1α), and mitochondrial transcription factor A (TFAM) in the endothelial cells. H2O2-induced mitochondrial dysfunction, as demonstrated by reduced mitochondrial membrane potential (Δψm) and ATP production, was rescued by SAL pretreatment. Taken together, these findings implicate that SAL could protect endothelium against H2O2-induced injury via promoting mitochondrial biogenesis and function, thus preventing the overactivation of oxidative stress-related downstream signaling pathways.

scholarly journals An increase in nitric oxide produced by rat peritoneal neutrophils is not involved in cell apoptosis

1995 ◽  
Vol 4 (3) ◽  
pp. 222-228 ◽  
Author(s):  
I. M. Fierro ◽  
C. Barja-Fidalgo ◽  
R. M. Canedo ◽  
F. Q. Cunha ◽  
S. H. Ferreira
Keyword(s):  
Nitric Oxide ◽  
Cell Apoptosis ◽  
No Synthase ◽  
The Other ◽  
Polymorphonuclear Neutrophils ◽  
No Production ◽  
Spontaneous Release ◽  
No Donor ◽  
Carrageenin Injection

Polymorphonuclear neutrophils (PMN) obtained from carrageenin-stimulated peritoneal cavities of rats, but not blood PMN, spontaneously produced nitric oxide (NO) when incubatedin vitro. Incubation of the cells with the NO synthase inhibitors, L-imino-ethyl-L-ornithine (L-NIO) or NG-monomethyl-L-arginine (L-NMMA), inhibited NO production. This inhibition could be reversed by L-arginine. Incubation of PMN with lipopolysaccharide (LPS) failed to enhance NO production. Pretreatment of the rats with dexamethasone (DEXA) prior to carrageenin injection or incubation of PMN with the glucocorticoidin vitropartially inhibited the spontaneous release of NO. On the other hand, when PMN obtained from DEXA pretreated rats were incubatedin vitrowith DEXA, NO synthase activity and hence NO generation were almost abolished. A similar inhibition was also observed following the addition of L-NIO or cycloheximide to cultures of carrageenin-elicited PMN. The NO production by PMN did not appear to be related to cell viability or apoptosis. Indeed, neither the blockade of NO generation by L-NIO nor the incubation of the neutrophils with a NO donor, S-nitroso-acetylpenicillamine (SNAP) modified the pattern of LDH release or DNA fragmentation. In summary, it appears that PMN migration triggers a continuous NO synthesis, and that NO produced by these cells is not related to their apoptosis.

scholarly journals Mitoflash biogenesis and its role in the autoregulation of mitochondrial proton electrochemical potential

2019 ◽  
Vol 151 (6) ◽  
pp. 727-737 ◽  
Author(s):  
Gaomin Feng ◽  
Beibei Liu ◽  
Jinghang Li ◽  
Tianlei Cheng ◽  
Zhanglong Huang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Complex I ◽  
Atp Synthesis ◽  
Electrochemical Potential ◽  
Cardiac Mitochondria ◽  
Entry Site ◽  
Complex Iv ◽  
Electron Transfer Chain ◽  
Atp Production ◽  
Transfer Chain

Respiring mitochondria undergo an intermittent electrical and chemical excitation called mitochondrial flash (mitoflash), which transiently uncouples mitochondrial respiration from ATP production. How a mitoflash is generated and what specific role it plays in bioenergetics remain incompletely understood. Here, we investigate mitoflash biogenesis in isolated cardiac mitochondria by varying the respiratory states and substrate supply and by dissecting the involvement of different electron transfer chain (ETC) complexes. We find that robust mitoflash activity occurs once mitochondria are electrochemically charged by state II/IV respiration (i.e., no ATP synthesis at Complex V), regardless of the substrate entry site (Complex I, Complex II, or Complex IV). Inhibiting forward electron transfer abolishes, while blocking reverse electron transfer generally augments, mitoflash production. Switching from state II/IV to state III respiration, to allow for ATP synthesis at Complex V, markedly diminishes mitoflash activity. Intriguingly, when mitochondria are electrochemically charged by the ATPase activity of Complex V, mitoflashes are generated independently of ETC activity. These findings suggest that mitoflash biogenesis is mechanistically linked to the build up of mitochondrial electrochemical potential rather than ETC activity alone, and may functionally counteract overcharging of the mitochondria and hence serve as an autoregulator of mitochondrial proton electrochemical potential.

The effect of ethanol and nitric oxide on the N-nitrosodimethylamine formation in HepG2 cells overexpressing CYP2E1

2005 ◽  
Vol 24 (9) ◽  
pp. 447-452
Author(s):  
Jakub Jabloński ◽  
Adam Holownia ◽  
Ewa Jablońska ◽  
Janina Moniuszko-Jakoniuk ◽  
Jan Braszko ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Hepg2 Cells ◽  
Culture Media ◽  
Inos Expression ◽  
The Other ◽  
No Production ◽  
Transfected Cells ◽  
Empty Vector ◽  
Inos Inhibitor ◽  
Oxide Synthase

The influence of lipopolysaccharide (LPS) and the nitric oxide synthase (iNOS) inhibitor-N-nitro-L-arginine on the formation of N-nitrosodimethylamine (NDMA) by HepG2 cells, engineered to overexpress CYP2E1, was assessed and compared with data from empty vector-transfected cells. HepG2 cells produced significant amounts of NDMA but its levels in the culture media of cells overexpressing CYP2E1 was significantly lower than in empty-vector transfected cells. LPS increased the formation of NDMA, the expression of the iNOS and the production of the nitric oxide (NO). On the other hand, L-NAME significantly decreased NDMA levels. The results above indicate that the synthesis of NDMA by HepG2 cells depends on NO production. Furthermore, ethanol did not affect iNOS expression but decreased NDMA levels in CYP2E1-transfected cells below the detection limit. It is probably caused by the increased N-nitrosodimethylamine metabolism. In conclusion, HepG2 cells' ability to synthesize NO with simultaneous CYP2E1 activation may lead to an increase of carcinogenic products of the NDMA metabolism.

scholarly journals Mitochondrial and metabolic remodeling in human skin fibroblasts in response to glucose availability

2021 ◽  
Author(s):  
Cláudio F. Costa ◽  
Sónia A. Pinho ◽  
Sonia L.C. Pinho ◽  
Inês Miranda-Santos ◽  
Olivia Bagshaw ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Model ◽  
Complete Removal ◽  
Culture Conditions ◽  
Dermal Fibroblasts ◽  
Physiological Level ◽  
Atp Production ◽  
Metabolic Remodeling ◽  
Cell Culture Conditions

AbstractCell culture conditions highly influence cell metabolism in vitro. This is relevant for preclinical assays, for which fibroblasts are an interesting cell model, with applications in regenerative medicine, diagnostics and therapeutic development for personalized medicine as well as in the validation of ingredients for cosmetics. Given these cells’ short lifespan in culture, we aimed to identify the best cell culture conditions and promising markers to study mitochondrial health and stress in Normal Human Dermal Fibroblasts (NHDF). We tested the effect of reducing glucose concentration in the cell medium from high glucose (HGm) to a more physiological level (LGm), or its complete removal and replacement by galactose (OXPHOSm), always in the presence of glutamine and pyruvate. We have demonstrated that only with OXPHOSm it was possible to observe the selective inhibition of mitochondrial ATP production. This reliance on mitochondrial ATP was accompanied by changes in oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), oxidation of citric acid cycle substrates, fatty acids, lactate and other substrates, mitochondrial network extension and polarization and changes in several key transcripts related to energy metabolism. We also evaluated the relevance of galactose, glutamine and pyruvate for OXPHOS stimulation, by comparing OCR and ECAR in the presence or absence of these substrates. Galactose and pyruvate seem to be important, but redundant, to promote OXPHOS, whereas glutamine was essential. We concluded that LGm does not promote significant metabolic changes but the short-term adaptation to OXPHOSm is ideal for studying mitochondrial health and stress in NHDF.Author ContributionsCC, SAP, SLCP and IMS performed experiments. TCO and PJO designed research and acquired funding. JS, and OB analyzed data. CC and TCO analyzed data and wrote the paper. All authors contributed to the final version of the manuscript.

scholarly journals Paracrine purinergic signaling determines lung endothelial nitric oxide production

2009 ◽  
Vol 296 (6) ◽  
pp. L901-L910 ◽  
Author(s):  
Rainer Kiefmann ◽  
Mohammad N. Islam ◽  
Jens Lindert ◽  
Kaushik Parthasarathi ◽  
Jahar Bhattacharya
Keyword(s):  
Nitric Oxide ◽  
Nitrosative Stress ◽  
Purinergic Receptor ◽  
Purinergic Signaling ◽  
No Production ◽  
Atp Production ◽  
Alveolar Epithelial ◽  
Lung Expansion ◽  
Ec Cells ◽  
Endothelial Nitric Oxide

Although the vascular bed is a major source of nitric oxide (NO) production, factors regulating the production remain unclear. We considered the role played by paracrine signaling. Determinations by fluorescence microscopy in isolated, blood-perfused rat and mouse lungs revealed that a brief lung expansion enhanced cytosolic Ca2+ (Ca2+cyt) oscillations in alveolar epithelial (AEC) and endothelial (EC) cells, and NO production in EC. Furthermore, as assessed by a novel microlavage assay, alveolar ATP production increased. Intra-alveolar microinfusion of the purinergic receptor antagonist, PPADS, and the nucleotide hydrolyzing enzyme, apyrase, each completely blocked the Ca2+cyt and NO responses in EC. Lung expansion induced Ca2+cyt oscillations in mice lacking the P2Y1, but not the P2Y2, purinergic receptors, which were located in the perivascular interstitium basolateral to AEC. Prolonged lung expansion instituted by mechanical ventilation at high tidal volume increased EC expression of nitrotyrosine, indicating development of nitrosative stress in lung microvessels. These findings reveal a novel mechanism in which mechanically induced purinergic signaling couples cross-compartmental Ca2+cyt oscillations to microvascular NO production.

246 EFFECT OF NITRIC OXIDE INHIBITION (N-ω-NITRO-L-ARGININE METHYL ESTER) AND SCAVENGER (METHYLENE BLUE) ON PLASMA MEMBRANE PEROXIDATION OF EQUINE CRYOPRESERVED SPERM

2013 ◽  
Vol 25 (1) ◽  
pp. 271 ◽  
Author(s):  
D. F. Silva ◽  
A. F. C. Andrade ◽  
M. C. Caldas-Bussiere ◽  
E. C. C. Celeghini ◽  
M. A. Alonso ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Lipid Peroxidation ◽  
Methylene Blue ◽  
Plasma Membrane ◽  
Methyl Ester ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
The Other ◽  
No Production ◽  
Membrane Peroxidation

The peroxidation of plasma membrane lipids has been claimed to be a major factor involved in sublethal cryodamage. Some authors have reported that reactive oxygen species (ROS) accumulation could be an important factor leading to further damage in post-thaw sperm. Oxidative stress occurring in the sperm is a phenomenon associated with increased rate of oxidation of cellular components and excessive production of ROS and nitrogen. The objective of this study was to evaluate the effect of NO inhibition [N-ω-nitro-l-arginine methyl ester (l-NAME)] and scavenger (methylene blue) on the plasma membrane peroxidation of equine cryopreserved capacitated sperm. Three ejaculates were obtained from each of three stallions (n = 9). Semen was packaged into 0.5-mL straws to a concentration of 200 × 106 sperm mL–1 in BotuCrio® extender and frozen using an automated technique with a programmed machine. Four straws were thawed in a water bath at 37°C for 30 s and centrifuged in bovine IVF media supplemented with sodium bicarbonate and BSA for the capacitation of equine sperm. The supernatant was withdrawn, and semen was then incubated in the same media with l-arginine, with or without the NO synthase inhibitor, l-NAME, and in media with l-arginine with or without the NO scavenger, methylene blue: treatment (T)1 = control; T2 = 10 mM l-arginine (based on previous experiments); T3 = 1 mM l-NAME; T4 = 100 mM methylene blue; T5 = 10 mM l-arginine + 1 mM l-NAME; and T6 = 10 mM l-arginine + 100 mM methylene blue for 60, 120, and 300 min at 38°C under 5% CO2. After incubation, cells presenting membrane peroxidation were identified using an association of the fluorescent probes C11-BODIPY581/591 (1 mg mL–1; D-3861) and PI (0.5 mg mL–1; L0770). Nitric oxide production was identified using a 4,5-diaminofluorescein-2/diacetate (10 µM) probe associated with PI. The H33342 probe was used to avoid those particles presenting the same size and granularity as sperm cells being included in the counting. Both evaluations were performed using flow cytometry. Data were analysed by ANOVA, and the means were compared within each time with Tukey’s test, with a level of significance of 5%, using SAS software (SAS Institute Inc., Cary, NC, USA). Lipid peroxidation of the membrane was not influenced by the treatments at the different times (P > 0.05). This characteristic was reduced for the groups treated with methylene blue (T4 and T6) at times 60, 120, and 300 min compared with the other treated groups. Nitric oxide produced by sperm was not influenced by treatment at different times (P > 0.05). However, methylene blue addition was able to decrease NO production in treatments T4 and T6 at all the incubation times evaluated compared with the other treatments. Therefore, methylene blue removed NO and decreased plasma membrane lipid peroxidation, suggesting an antioxidant role of this scavenger. On the other hand, more research is needed to elucidate the mechanism of action of methylene blue on the physiology of cryopreserved equine sperm. Supported by FAPESP (grant 2009/54906-5).

Differing roles of mitochondrial nitric oxide synthase in cardiomyocytes and urothelial cells

2004 ◽  
Vol 286 (1) ◽  
pp. H13-H21 ◽  
Author(s):  
Anthony Kanai ◽  
Michael Epperly ◽  
Linda Pearce ◽  
Lori Birder ◽  
Mark Zeidel ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Manganese Superoxide Dismutase ◽  
Cell Damage ◽  
Mdx Mice ◽  
Permeability Barrier ◽  
No Production ◽  
Scanning Electron Micrographs ◽  
Urothelial Cells ◽  
Atp Production ◽  
Umbrella Cells

The existence of mitochondrial nitric oxide (NO) synthase (mtNOS) has been controversial since it was first reported in 1995. We have addressed this issue by making direct microsensor measurements of NO production in the mitochondria isolated from mouse hearts. Mitochondrial NO production was stimulated by Ca2+ and inhibited by blocking electrogenic Ca2+ uptake or by using NOS antagonists. Cardiac mtNOS was identified as the neuronal isoform by the absence of NO production in the mitochondria of mice lacking the neuronal but not the endothelial or inducible isoforms. In cardiomyocytes from dystrophin-deficient ( mdx) mice, elevated intracellular Ca2+, increased mitochondrial NO production, slower oxidative phosphorylation, and decreased ATP production were detected. Inhibition of mtNOS increased contractility in mdx but not in wild-type cardiomyocytes, indicating that mtNOS may protect the cells from overcontracting. mtNOS was also implicated in radiation-induced cell damage. In irradiated rat/mouse urinary bladders, we have evidence that mitochondrially produced NO damages the urothelial “umbrella” cells that line the bladder lumen. This damage disrupts the permeability barrier thereby creating the potential to develop radiation cystitis. RT-PCR and Southern blot analyses indicate that mtNOS is restricted to the umbrella cells, which scanning electron micrographs show are selectively damaged by radiation. Simultaneous microsensor measurements demonstrate that radiation increases NO and peroxynitrite (ONOO–) production in these cells, which can be prevented by transfection with manganese superoxide dismutase (MnSOD) or instillation of NOS antagonists during irradiation or irradiation of bladders devoid of mtNOS. These studies demonstrate that mtNOS is in the cardiomyocytes and urothelial cells, that it is derived from the neuronal isoform, and that it can be either protective or detrimental.

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