Nitric Oxide Potentiates cAMP-Gated Cation Current in Feeding Neurons of Pleurobranchaea californica Independent of cAMP and cGMP Signaling Pathways

2006 ◽  
Vol 95 (5) ◽  
pp. 3219-3227 ◽  
Author(s):  
N. G. Hatcher
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Pleurobranchaea Californica ◽  
Cation Current ◽  
Cgmp Signaling ◽  
Camp And Cgmp

scholarly journals Nitric Oxide Potentiates cAMP-Gated Cation Current by Intracellular Acidification in Feeding Neurons of Pleurobranchaea

2010 ◽  
Vol 104 (2) ◽  
pp. 742-745 ◽  
Author(s):  
Kurt Potgieter ◽  
Nathan G. Hatcher ◽  
Rhanor Gillette ◽  
Catherine R. McCrohan
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Intracellular Ph ◽  
Camp Signaling ◽  
Intracellular Acidification ◽  
Ph Indicator ◽  
Intracellular Injection ◽  
Cation Current ◽  
Motor Network ◽  
Important Regulator

A pH-sensitive cAMP-gated cation current ( INa,cAMP) is widely distributed in neurons of the feeding motor networks of gastropods. In the sea slug Pleurobranchaea this current is potentiated by nitric oxide (NO), which itself is produced by many feeding neurons. The action of NO is not dependent on either cGMP or cAMP signaling pathways. However, we found that NO potentiation of INa,cAMP in the serotonergic metacerebral cells could be blocked by intracellular injection of MOPS buffer (pH 7.2). In neurons injected with the pH indicator BCECF, NO induced rapid intracellular acidification to several tenths of a pH unit. Intracellular pH has not previously been identified as a specific target of NO, but in this system NO modulation of INa,cAMP via pHi may be an important regulator of the excitability of the feeding motor network.

scholarly journals Inhibition of germinal vesicle breakdown by antioxidants and the roles of signaling pathways related to nitric oxide and cGMP during meiotic resumption in oocytes of a marine worm

Reproduction ◽  
2012 ◽  
Vol 143 (3) ◽  
pp. 261-270 ◽  
Author(s):  
Stephen A Stricker
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Soluble Guanylate Cyclase ◽  
Germinal Vesicle ◽  
Germinal Vesicle Breakdown ◽  
Nos Inhibitors ◽  
Cgmp Signaling ◽  
Sgc Stimulators ◽  
Potential Interactions ◽  
Downstream Mediator

In mammalian oocytes, cAMP elevations prevent the resumption of meiotic maturation and thereby block nuclear disassembly (germinal vesicle breakdown (GVBD)), whereas nitric oxide (NO) and its downstream mediator cGMP can either inhibit or induce GVBD. Alternatively, some invertebrate oocytes use cAMP to stimulate, rather than inhibit, GVBD, and in such cases, the effects of NO/cGMP signaling on GVBD remain unknown. Moreover, potential interactions between NO/cGMP and AMP-activated kinase (AMPK) have not been assessed during GVBD. Thus, this study analyzed intraoocytic signaling pathways related to NO/cGMP in a marine nemertean worm that uses cAMP to induce GVBD. For such tests, follicle-free nemertean oocytes were stimulated to mature by seawater (SW) and cAMP elevators. Based on immunoblots and NO assays of maturing oocytes, SW triggered AMPK deactivation, NO synthase (NOS) phosphorylation, and an NO elevation. Accordingly, SW-induced GVBD was blocked by treatments involving the AMPK agonist AICAR, antioxidants, the NO scavenger carboxy-PTIO, NOS inhibitors, and cGMP antagonists that target the NO-stimulated enzyme, soluble guanylate cyclase (sGC). Conversely, SW solutions combining NO/cGMP antagonists with a cAMP elevator restored GVBD. Similarly, AICAR plus a cAMP-elevating drug reestablished GVBD while deactivating AMPK and phosphorylating NOS. Furthermore, sGC stimulators and 8-Br-cGMP triggered GVBD. Such novel results indicate that NO/cGMP signaling can upregulate SW-induced GVBD and that cAMP-elevating drugs restore GVBD by overriding the inhibition of various NO/cGMP downregulators, including AMPK. Moreover, considering the opposite effects of intraoocytic cAMP in nemerteans vs mammals, these data coincide with previous reports that NO/cGMP signaling blocks GVBD in rats.

scholarly journals Nitric Oxide Potentiates cAMP-Gated Cation Current in Feeding Neurons of Pleurobranchaea californica Independent of cAMP and cGMP Signaling Pathways

2006 ◽  
Vol 95 (5) ◽  
pp. 3219-3227 ◽  
Author(s):  
Nathan G. Hatcher ◽  
Leland C. Sudlow ◽  
Leonid L. Moroz ◽  
Rhanor Gillette
Keyword(s):  
Nitric Oxide ◽  
Buccal Ganglion ◽  
Giant Neuron ◽  
Cation Current ◽  
Motor Network ◽  
Current Saturation ◽  
Degradation Rates ◽  
Cgmp Signaling ◽  
Current Activation ◽  
Response Measures

Critical roles for nitric oxide (NO) in regulating cell and tissue physiology are broadly appreciated, but aspects remain to be explored. In the mollusk Pleurobranchaea, NO synthase activity is high in CNS ganglia containing motor networks for feeding and locomotion, where a cAMP-gated cation current ( INa,cAMP) is also prominent in many neurons. We examined effects of NO on INa,cAMP using voltage-clamp methods developed to analyze cAMP signaling in the live neuron, focusing on the identified metacerebral giant neuron of the feeding network. NO donors enhanced the INa,cAMP response to injected cAMP by an averaged 85%. In dose-response measures, NO increased the current stimulated by cAMP injection without altering either apparent cAMP binding affinity or cooperativity of current activation. NO did not detectably alter levels of native cAMP or synthesis or degradation rates as observable in both current saturation and decay rate of INa,cAMP responses to cAMP injection. NO actions were not exerted by cGMP signaling, as they were not mimicked by cGMP analogue nor blocked by inhibitors of guanylate cyclase and protein kinase G. NO potentiation of INa,cAMP was broadly distributed among many other neurons of the feeding motor network in the buccal ganglion. However, NO did not affect a second type of INa,cAMP found in locomotor neurons of the pedal ganglia. These results suggest that NO acts through a novel mechanism to regulate the gain of cAMP-dependent neuromodulatory pathways that activate INa,cAMP and may thereby affect the set points of feeding network excitability and reactivity to exogenous input.

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

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.

scholarly journals Pro-Angiogenic Effects of Resveratrol in Brain Endothelial Cells: Nitric Oxide-Mediated Regulation of Vascular Endothelial Growth Factor and Metalloproteinases

2012 ◽  
Vol 32 (5) ◽  
pp. 884-895 ◽  
Author(s):  
Fabricio Simão ◽  
Aline S Pagnussat ◽  
Ji Hae Seo ◽  
Deepti Navaratna ◽  
Wendy Leung ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Vascular Endothelial Growth Factor ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Signaling Pathways ◽  
Tube Formation ◽  
Mitogen Activated Protein Kinase ◽  
Vascular Endothelial ◽  
Cerebral Endothelial Cells ◽  
Endothelial Growth Factor

Resveratrol may be a powerful way of protecting the brain against a wide variety of stress and injury. Recently, it has been proposed that resveratrol not only reduces brain injury but also promotes recovery after stroke. But the underlying mechanisms are unclear. Here, we tested the hypothesis that resveratrol promotes angiogenesis in cerebral endothelial cells and dissected the signaling pathways involved. Treatment of cerebral endothelial cells with resveratrol promoted proliferation, migration, and tube formation in Matrigel assays. Consistent with these pro-angiogenic responses, resveratrol altered endothelial morphology resulting in cytoskeletal rearrangements of β-catenin and VE-cadherin. These effects of resveratrol were accompanied by activation of phosphoinositide 3 kinase (PI3-K)/Akt and Mitogen-Activated Protein Kinase (MAPK)/ERK signaling pathways that led to endothelial nitric oxide synthase upregulation and increased nitric oxide (NO) levels. Subsequently, elevated NO signaling increased vascular endothelial growth factor and matrix metalloproteinase levels. Sequential blockade of these signaling steps prevented resveratrol-induced angiogenesis in cerebral endothelial cells. These findings provide a mechanistic basis for the potential use of resveratrol as a candidate therapy to promote angiogenesis and neurovascular recovery after stroke.

MicroRNA-155 Amplifies Nitric Oxide/cGMP Signaling and Impairs Vascular Angiotensin II Reactivity in Septic Shock

2018 ◽  
Vol 46 (9) ◽  
pp. e945-e954 ◽  
Author(s):  
Francisco Vasques-Nóvoa ◽  
Tiago L. Laundos ◽  
Rui J. Cerqueira ◽  
Catarina Quina-Rodrigues ◽  
Ricardo Soares-dos-Reis ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Septic Shock ◽  
Angiotensin Ii ◽  
Cgmp Signaling

The nitric oxide–cGMP signaling pathway plays a significant role in tolerance to the analgesic effect of morphine

2011 ◽  
Vol 89 (2) ◽  
pp. 89-95 ◽  
Author(s):  
Ercan Ozdemir ◽  
Ihsan Bagcivan ◽  
Nedim Durmus ◽  
Ahmet Altun ◽  
Sinan Gursoy
Keyword(s):  
Nitric Oxide ◽  
Analgesic Effect ◽  
Soluble Guanylate Cyclase ◽  
Morphine Tolerance ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Albino Rats ◽  
Tail Flick ◽  
Analgesic Effects ◽  
Cgmp Signaling

Although the phenomenon of opioid tolerance has been widely investigated, neither opioid nor nonopioid mechanisms are completely understood. The aim of the present study was to investigate the role of the nitric oxide (NO)–cyclic guanosine monophosphate (cGMP) pathway in the development of morphine-induced analgesia tolerance. The study was carried out on male Wistar albino rats (weighing 180–210 g; n = 126). To develop morphine tolerance, animals were given morphine (50 mg/kg; s.c.) once daily for 3 days. After the last dose of morphine was injected on day 4, morphine tolerance was evaluated. The analgesic effects of 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1), BAY 41-2272, S-nitroso-N-acetylpenicillamine (SNAP), NG-nitro-l-arginine methyl ester (L-NAME), and morphine were considered at 15 or 30 min intervals (0, 15, 30, 60, 90, and 120 min) by tail-flick and hot-plate analgesia tests (n = 6 in each study group). The results showed that YC-1 and BAY 41-2272, a NO-independent activator of soluble guanylate cyclase (sGC), significantly increased the development and expression of morphine tolerance, and L-NAME, a NO synthase (NOS) inhibitor, significantly decreased the development of morphine tolerance. In conclusion, these data demonstrate that the nitric oxide–cGMP signal pathway plays a pivotal role in developing tolerance to the analgesic effect of morphine.

scholarly journals Differential Induction of the Toll-Like Receptor 4-MyD88-Dependent and -Independent Signaling Pathways by Endotoxins

2005 ◽  
Vol 73 (5) ◽  
pp. 2940-2950 ◽  
Author(s):  
Susu M. Zughaier ◽  
Shanta M. Zimmer ◽  
Anup Datta ◽  
Russell W. Carlson ◽  
David S. Stephens
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Lipid A ◽  
Raw 264.7 ◽  
Receptor Complex ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Nitric Oxide Release ◽  
Tnf Α ◽  
Dependent Pathway

ABSTRACT The biological response to endotoxin mediated through the Toll-like receptor 4 (TLR4)-MD-2 receptor complex is directly related to lipid A structure or configuration. Endotoxin structure may also influence activation of the MyD88-dependent and -independent signaling pathways of TLR4. To address this possibility, human macrophage-like cell lines (THP-1, U937, and MM6) or murine macrophage RAW 264.7 cells were stimulated with picomolar concentrations of highly purified endotoxins. Harvested supernatants from previously stimulated cells were also used to stimulate RAW 264.7 or 23ScCr (TLR4-deficient) macrophages (i.e., indirect induction). Neisseria meningitidis lipooligosaccharide (LOS) was a potent direct inducer of the MyD88-dependent pathway molecules tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 3α (MIP-3α), and the MyD88-independent molecules beta interferon (IFN-β), nitric oxide, and IFN-γ-inducible protein 10 (IP-10). Escherichia coli 55:B5 and Vibrio cholerae lipopolysaccharides (LPSs) at the same pmole/ml lipid A concentrations induced comparable levels of TNF-α, IL-1β, and MIP-3α, but significantly less IFN-β, nitric oxide, and IP-10. In contrast, LPS from Salmonella enterica serovars Minnesota and Typhimurium induced amounts of IFN-β, nitric oxide, and IP-10 similar to meningococcal LOS but much less TNF-α and MIP-3α in time course and dose-response experiments. No MyD88-dependent or -independent response to endotoxin was seen in TLR4-deficient cell lines (C3H/HeJ and 23ScCr) and response was restored in TLR4-MD-2-transfected human embryonic kidney 293 cells. Blocking the MyD88-dependent pathway by DNMyD88 resulted in significant reduction of TNF-α release but did not influence nitric oxide release. IFN-β polyclonal antibody and IFN-α/β receptor 1 antibody significantly reduced nitric oxide release. N. meningitidis endotoxin was a potent agonist of both the MyD88-dependent and -independent signaling pathways of the TLR4 receptor complex of human macrophages. E. coli 55:B5 and Vibrio cholerae LPS, at the same picomolar lipid A concentrations, selectively induced the MyD88-dependent pathway, while Salmonella LPS activated the MyD88-independent pathway.

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