Suppression of neuropeptide Y1 receptor function in SK-N-MC cells by nitric oxide

1997 ◽  
Vol 273 (2) ◽  
pp. C618-C621 ◽  
Author(s):  
J. Dotsch ◽  
J. Hanze ◽  
O. Beste ◽  
J. Behrendt ◽  
W. M. Weber ◽  
...  

The neuropeptide Y1 receptor (NPY1) predominantly mediates the vasoconstrictor effects of NPY in smooth muscle cells. The present experiments were planned to study the direct influence of the vasodilator nitric oxide (NO) on NPY1-receptor function. SK-N-MC and CHP-234 cells expressing Y1 and Y2 receptor, respectively, were incubated with the NO donors sodium nitroprusside (SNP), 3-morpholinosydnonimine (SIN-1), and S-nitroso-N-acetyl-penicillamine (SNAP). Receptor binding, Y1-receptor mRNA expression by Northern blot, and adenosine 3',5'-cyclic monophosphate (cAMP) and intracellular Ca2+ concentration ([Ca2+]i) responses were studied. SNP, SIN-1, and SNAP decreased normal binding of NPY to the NPY1 receptor in SK-N-MC cells in a concentration-dependent manner. SNP (500 microM), SIN-1 (1,000 microM), and SNAP (500 microM) significantly decreased binding to approximately 50%. The cell viability was not reduced. None of the NO donors affected Y2 receptor binding. Pretreatment with SNP significantly attenuated NPY-induced inhibition of cAMP formation in SK-N-MC cells but had no effect on CHP cells. The NPY-induced [Ca2+]i response was reduced to 50% by SNP pretreatment. NPY1 mRNA expression was reduced to one-third after SNAP treatment of SK-N-MC cells. In vitro, NPY1 receptor function of SK-N-MC cells is inhibited by NO-donor incubation on an mRNA level.

1998 ◽  
Vol 274 (1) ◽  
pp. C245-C252 ◽  
Author(s):  
Junsuke Igarashi ◽  
Masashi Nishida ◽  
Shiro Hoshida ◽  
Nobushige Yamashita ◽  
Hiroaki Kosaka ◽  
...  

The effects of nitric oxide (NO) produced by cardiac inducible NO synthase (iNOS) on myocardial injury after oxidative stress were examined. Interleukin-1β induced cultured rat neonatal cardiac myocytes to express iNOS. After induction of iNOS,l-arginine enhanced NO production in a concentration-dependent manner. Glutathione peroxidase (GPX) activity in myocytes was attenuated by elevated iNOS activity and by an NO donor, S-nitroso- N-acetyl-penicillamine (SNAP). Although NO production by iNOS did not induce myocardial injury, NO augmented release of lactate dehydrogenase from myocyte cultures after addition of H2O2(0.1 mM, 1 h). Inhibition of iNOS with Nω-nitro-l-arginine methyl ester ameliorated the effects of NO-enhancing treatments on myocardial injury and GPX activity. SNAP augmented the myocardial injury induced by H2O2. Inhibition of GPX activity with antisense oligodeoxyribonucleotide for GPX mRNA increased myocardial injury by H2O2. Results suggest that the induction of cardiac iNOS promotes myocardial injury due to oxidative stress via inactivation of the intrinsic antioxidant enzyme, GPX.


2003 ◽  
Vol 69 (5) ◽  
pp. 2521-2532 ◽  
Author(s):  
C. Lange ◽  
D. Rittmann ◽  
V. F. Wendisch ◽  
M. Bott ◽  
H. Sahm

ABSTRACT Addition of l-valine (50 to 200 mM) to glucose minimal medium had no effect on the growth of wild-type Corynebacterium glutamicum ATCC 13032 but inhibited the growth of the derived valine production strain VAL1 [13032 ΔilvA ΔpanBC(pJC1ilvBNCD)] in a concentration-dependent manner. In order to explore this strain-specific valine effect, genomewide expression profiling was performed using DNA microarrays, which showed that valine caused an increased ilvBN mRNA level in VAL1 but not in the wild type. This unexpected result was confirmed by an increased cellular level of the ilvB protein product, i.e., the large subunit of acetohydroxyacid synthase (AHAS), and by an increased AHAS activity of valine-treated VAL1 cells. The conclusion that valine caused the limitation of another branched-chain amino acid was confirmed by showing that high concentrations of l-isoleucine could relieve the valine effect on VAL1 whereas l-leucine had the same effect as valine. The valine-caused isoleucine limitation was supported by the finding that the inhibitory valine effect was linked to the ilvA deletion that results in isoleucine auxotrophy. Taken together, these results implied that the valine effect is caused by competition for uptake of isoleucine by the carrier BrnQ, which transports all branched-chained amino acids. Indeed, valine inhibition could also be relieved by supplementing VAL1 with the dipeptide isoleucyl-isoleucine, which is taken up by a dipeptide transport system rather than by BrnQ. Interestingly, addition of external valine stimulated valine production by VAL1. This effect is most probably due to a reduced carbon usage for biomass production and to the increased expression of ilvBN, indicating that AHAS activity may still be a limiting factor for valine production in the VAL1 strain.


1999 ◽  
Vol 344 (3) ◽  
pp. 837-844 ◽  
Author(s):  
Atsushi MITSUMOTO ◽  
Kwi-Ryeon KIM ◽  
Genichiro OSHIMA ◽  
Manabu KUNIMOTO ◽  
Katsuya OKAWA ◽  
...  

To clarify the molecular mechanisms of nitric oxide (NO) signalling, we examined the NO-responsive proteins in cultured human endothelial cells by two-dimensional (2D) PAGE. Levels of two proteins [NO-responsive proteins (NORPs)] with different pI values responded to NO donors. One NORP (pI 5.2) appeared in response to NO, whereas another (pI 5.0) disappeared. These proteins were identified as a native form and a modified form of human glyoxalase I (Glox I; EC 4.4.1.5) by peptide mapping, microsequencing and correlation between the activity and the isoelectric shift. Glox I lost activity in response to NO, and all NO donors tested inhibited its activity in a dose-dependent manner. Activity and normal electrophoretic mobility were restored by dithiothreitol and by the removal of sources of NO from the culture medium. Glox I was selectively inactivated by NO; compounds that induce oxidative stress (H2O2, paraquat and arsenite) failed to inhibit this enzyme. Our results suggest that NO oxidatively modifies Glox I and reversibly inhibits the enzyme's activity. The inactivation of Glox I by NO was more effective than that of glyceraldehyde-3-phosphate dehydrogenase (G3PDH), another NO-sensitive enzyme. Thus Glox I seems to be a novel NO-responsive protein that is more sensitive to NO than G3PDH.


1996 ◽  
Vol 1 (3) ◽  
pp. 203-209 ◽  
Author(s):  
Roberto Pedrinelli

Background To investigate the effects of dipyridamole, a drug with phosphodiesterase-, adenosine reuptake-inhibiting, and prostacyclin-stimulating activity on the biological actions of nitric oxide, 30 norepinephrine-precontracted subcutaneous arterioles were prepared from specimens removed during surgery. Methods and Results Specimens were mounted on a myograph and relaxed through either acetylcholine, a muscarinic agonist that stimulates endothelial nitric oxide production, or sodium nitroprusside, an endothelium-independent vasodilator. Studies were performed under control conditions and after dipyridamole which potentiated in a concentration-dependent manner the vasorelaxation induced both by acetylcholine and sodium nitroprusside, indicating an endothelium-independent mechanism of action. The contribution of nitric oxide to the relaxation produced by acetylcholine was confirmed by N-monomethyl-L-arginine, a nitric oxide synthase inhibitor. In contrast, indomethacin, a cyclo-oxygenase inhibitor, was ineffective, indicating that prostacyclin stimulation could not explain the effect of dipyridamole. CGS 21680 C, an A2-selective adenosine receptor agonist insensitive to tissue deaminase, did not influence the relaxations induced by acetylcholine, suggesting that interference with adenosine metabolism was not implicated in the potentiating action of dipyridamole. Conclusion Dipyridamole potentiated the vasorelaxing effect of acetylcholine and sodium nitroprusside in human subcutaneous arterioles; neither prostacyclin stimulation nor A2 adenosine receptor stimulation could explain this effect. The data are consistent with an increase in intracellular cyclic 3’ 5'-guanosine monophosphate levels secondary to the phosphodiesterase-inhibiting properties of the drug.


Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3094 ◽  
Author(s):  
Jun Yin ◽  
Han Hyuk Kim ◽  
In Hyeok Hwang ◽  
Dong Hee Kim ◽  
Min Won Lee

Quercus mongolica Fisch. ex Ledeb. (QM) has been used as an oriental traditional medicine to relieve hemorrhoids, fever, and enteritis. We screened the inhibitory activities of the extracts and compounds (1–6) isolated from QM on the production of inflammatory cytokines and chemokines to evaluate their anti-inflammatory activities. Further, we evaluated the expression levels of cytokines, chemokines, and immune factors on pedunculagin (PC, 1), which was selected from isolated compounds (1–6) because of its potential anti-inflammation effect. Additionally, we evaluated whether the inflammation mitigation effects of PC (1) following UVB exposure in keratinocytes occurred because of nuclear factor (NF)-κB and signal transducer and activator of transcription (STAT)/Janus kinase (JAK) activation. PC (1) remarkably suppressed interleukin (IL)-6, IL-10, IL-13, and monocyte chemoattractant protein-1 (MCP-1) mRNA expression and reduced the mRNA expression level of Cyclooxygenase-2 (COX-2) and also reduced the phosphorylation of p38 mitogen-activated protein kinases (p38), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) in a concentration-dependent manner.


1993 ◽  
Vol 264 (6) ◽  
pp. R1119-R1124 ◽  
Author(s):  
C. Bjenning ◽  
N. Hazon ◽  
A. Balasubramaniam ◽  
S. Holmgren ◽  
J. M. Conlon

Neuropeptide Y is present in sympathetic nerves in the mammalian cardiovascular system. This study has investigated the distribution of neuropeptide Y in the cardiovascular and gastrointestinal systems and the effect of dogfish neuropeptide Y and related peptides on cardiovascular tissue of an elasmobranch fish, the common dogfish (Scyliorhinus canicula). Neuropeptide Y-like immunoreactivity is present in varicose nerve fibers innervating dogfish gut and cardiovascular tissue and in endocrine cells of the dogfish spiral intestine. Dogfish neuropeptide Y, dogfish peptide YY, and porcine neuropeptide Y contract the dogfish afferent branchial artery in a concentration-dependent manner. The effect is not inhibited by the presence of tetrodotoxin or by removal of the endothelium. The mammalian Y1 receptor selective agonist [Leu31Pro34]NPY but not the mammalian Y2 receptor selective agonist neuropeptide Y-(13-36) peptide has vasoconstrictor properties in this system, suggesting that the receptor mediating the vasoconstriction resembles the mammalian Y1 receptor more than the Y2 receptor.


1992 ◽  
Vol 263 (6) ◽  
pp. F1020-F1025 ◽  
Author(s):  
R. M. Edwards ◽  
M. Pullen ◽  
P. Nambi

The effects of endothelins (ET) on guanosine 3',5'-cyclic monophosphate (cGMP) levels in intact rat glomeruli were examined. ET-3 produced a rapid approximately fivefold increase in cGMP levels with the maximum effect occurring at 1 min. The ET-3-induced increase in cGMP accumulation occurred in the absence and presence of 3-isobutyl-1-methylxanthine. ET-1, ET-2, ET-3, and the structurally related toxin, sarafotoxin S6c, all increased glomerular cGMP levels in a concentration-dependent manner and with similar potencies (EC50 approximately 15-30 nM). The L-arginine analogue, N omega-nitro-L-arginine (L-NNA), reduced basal levels of cGMP and also totally inhibited ET-induced increases in cGMP as did methylene blue, an inhibitor of soluble guanylate cyclase. The effect of L-NNA was attenuated by L-arginine but not by D-arginine. The stimulation of cGMP accumulation by ET-3 was dependent on extracellular Ca2+ and was additive to atriopeptin III but not to acetylcholine. The ETA-selective antagonist, BQ 123, had no effect on ET-3-induced formation of cGMP. Glomerular membranes displayed high-affinity (Kd = 130-150 pM) and high-density (approximately 2.0 pmol/mg) binding sites for 125I-ET-1 and 125I-ET-3. ET-1, ET-3, and sarafotoxin S6c displaced 125I-ET-1 binding to glomerular membranes with similar affinities. BQ 123 had no effect on 125I-ET-1 binding. We conclude that ET increases cGMP levels in glomeruli by stimulating the formation of a nitric oxide-like factor that activates soluble guanylate cyclase. This effect of ET appears to be mediated by activation of ETB receptors and may serve to modulate the contractile effects of ET.


2002 ◽  
Vol 80 (8) ◽  
pp. 777-782 ◽  
Author(s):  
Masa-aki Hattori ◽  
Yukio Kato ◽  
Noboru Fujihara

The presence of endothelial nitric oxide synthase (eNOS) has been found in porcine oocytes, but its mRNA and protein levels remain relatively constant during hormonal stimulation. The present study was designed to determine the effect of retinoic acid on eNOS regulation in porcine oocytes during follicle-stimulating hormone (FSH) stimulation. Cumulus–oocyte complexes (COCs), prepared from small antral follicles of immature porcine ovaries, were cultured for 15 h and treated with FSH for an additional 48 h. eNOS mRNA and its protein were analyzed by reverse transcription – polymerase chain reaction and Western blotting, respectively. Retinoic acid had an inhibitory effect on the level of oocyte eNOS mRNA in a dose-dependent manner if COCs were exposed to retinoic acid before FSH stimulation. The inhibition of FSH action was reflected in a decrease in expression of c-fos mRNA. eNOS protein also decreased to approximately 50% of the control after exposure to 10 μM retinoic acid. However, the ability of NO synthesis was abolished in the oocytes prepared from retinoic acid pretreated COCs. These results suggest that retinoic acid has a strong inhibitory action on eNOS mRNA level and NO synthesis in the porcine oocyte.Key words: oocyte, retinoic acid, NO synthesis, eNOS, RT–PCR.


2019 ◽  
Vol 9 (10) ◽  
pp. 2144 ◽  
Author(s):  
Woon Yong Choi ◽  
Jae-Hun Sim ◽  
Jung-Youl Lee ◽  
Do Hyung Kang ◽  
Hyeon Yong Lee

The Spirulina maxima exact from a non-thermal ultrasonic process (UE) contains 17.5 mg/g of total chlorophyll, compared to 6.24 mg/g of chlorophyll derived from the conventional 70% ethanol extraction at 80 °C for 12 h (EE). The UE also showed relatively low cytotoxicity against murine microglial cells (BV-2) and inhibited the production of the inflammatory mediators, NO and PGE2. The UE also effectively suppresses both mRNA expression and the production of pro-inflammatory cytokines, such as TNF-α, IL-6 and IL-1β, in a concentration-dependent manner. Notably, TNF-α gene and protein production were most strongly down-regulated, while IL-6 was the least affected by all ranges of treatment concentrations. This work first demonstrated a quantitative correlation between mRNA expression and the production of cytokines, showing that suppression of TNF-α gene expression was most significantly correlated with its secretion. These results clearly proved that the anti-inflammatory effects of Spirulina extract from a nonthermal ultrasonic process, which yielded high concentrations of intact forms of chlorophylls, were increased two-fold compared to those of conventional extracts processed at high temperature.


2003 ◽  
Vol 22 (2) ◽  
pp. 81-86 ◽  
Author(s):  
G. B. Yi ◽  
D. Mc Clendon ◽  
D. Desaiah ◽  
J. Goddard ◽  
A. Lister ◽  
...  

Massive, multiple fire ant, Solenopsis invicta, stings are often treated aggressively, particularly in the elderly, despite limited evidence of systemic toxicity due to the venom. Over 95% of the S. invicta venom is composed of piperidine alkaloid components, whose toxicity, if any, is unknown. To assess a possible pharmacological basis for systemic toxicity, an alkaloid-rich, protein-free methanol extract of the venom from whole ants was assayed for inhibitory activity on the following nitric oxide synthase (NOS) isoforms, rat cerebellar neuronal (n NOS), bovine recombinant endothelial (e NOS), and murine recombinant immunologic (i NOS). Cytosolic NOS activity was determined by measuring the conversion of [3H]arginine to [3H]citrulline in vitro. Rat n NOS activity was inhibited significantly and in a concentration-dependent manner by the alkaloid-rich venom extract. For n NOS, enzyme activity was inhibited by approximately 50% with 0.33 ± 0.06 μgg of this venom extract, and over 95% inhibition of the three isoforms, n NOS, e NOS, and i NOS, was found with doses of 60 μg in 60-μl reaction mixture. These results indicate that the alkaloid components of S. invicta venom can produce potent inhibition of all three major NOS isoforms. Isosolenopsin A ( cis-2-methyl-6-undecylpiperidine), a naturally occurring fire ant piperidine alkaloid, was synthesized and tested for inhibitory activity against the three NOS isoforms. Enzyme activities for n NOS and e NOS were over 95% inhibited with 1000 μM of isosolenopsin A, whereas the activity of i NOS was inhibited by only about 20% at the same concentration. The IC50 for each of three NOS isoforms was approximately 18 ± 3.9 μM for n NOS, 156 ± 10 μM for e NOS, and >1000 μM for i NOS, respectively. Kinetic studies showed isosolenopsin A inhibition to be noncompetitive with L-arginine ( Ki = 19 ± 2 μM). The potency of isosolenopsin A as an inhibitor of n NOS compares favorably with the inhibitory potency of widely used n NOS inhibitors. Inhibition of NOS isoforms by isosolenopsin A and structurally similar compounds may have toxicological significance with respect to adverse reactions to fire ant stings.


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