Astrocyte Indoleamine 2,3-Dioxygenase Is Induced by the TLR3 Ligand Poly(I:C): Mechanism of Induction and Role in Antiviral Response

ABSTRACT Indoleamine 2,3-dioxygenase (IDO) is the first and rate-limiting enzyme in the kynurenine pathway of tryptophan catabolism and has been implicated in neurotoxicity and suppression of the antiviral T-cell response in HIV encephalitis (HIVE). Here we show that the Toll-like receptor 3 (TLR3) ligand poly(I:C) (PIC) induces the expression of IDO in human astrocytes. PIC was less potent than gamma interferon (IFN-γ) but more potent than IFN-β in inducing IDO. PIC induction of IDO was mediated in part by IFN-β but not IFN-γ, and both NF-κB and interferon regulatory factor 3 (IRF3) were required. PIC also upregulated TLR3, thereby augmenting the primary (IFN-β) and secondary (IDO and viperin) response genes upon subsequent stimulation with PIC. In HIVE, the transcripts for TLR3, IFN-β, IDO, and viperin were increased and IDO immunoreactivity was detected in reactive astrocytes as well as macrophages and microglia. PIC caused suppression of intracellular replication of human immunodeficiency virus pseudotyped with vesicular stomatitis virus G protein and human cytomegalovirus in a manner dependent on IRF3 and IDO. The involvement of IDO was demonstrated by partial but significant reversal of the PIC-mediated antiviral effect by IDO RNA interference and/or tryptophan supplementation. Importantly, the cytokine interleukin-1 abolished IFN-γ-induced IDO enzyme activity in a nitric oxide-dependent manner without suppressing protein expression. Our results demonstrate that IDO is an innate antiviral protein induced by double-stranded RNA and suggest a therapeutic utility for PIC in human viral infections. They also show that IDO activity can be dissociated from protein expression, indicating that the local central nervous system cytokine and nitric oxide environment determines IDO function.

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Continuing Effect of Cytokines and Toll-Like Receptor Agonists on Indoleamine-2,3-Dioxygenase-1 in Human Periodontal Ligament Stem/Stromal Cells

Cells ◽

10.3390/cells9122696 ◽

2020 ◽

Vol 9 (12) ◽

pp. 2696

Author(s):

Christian Behm ◽

Alice Blufstein ◽

Johannes Gahn ◽

Barbara Kubin ◽

Andreas Moritz ◽

...

Keyword(s):

Protein Expression ◽

Enzymatic Activity ◽

Stromal Cells ◽

Periodontal Ligament ◽

Dependent Manner ◽

Toll Like Receptor ◽

Indoleamine 2,3 Dioxygenase ◽

Tnf Α ◽

Inflammatory Stimuli ◽

Ifn Γ

Transplanted mesenchymal stem/stromal cells (MSCs) are a promising and innovative approach in regenerative medicine. Their regenerative potential is partly based upon their immunomodulatory activities. One of the most investigated immunomediators in MSCs, such as in periodontal ligament-derived MSCs (hPDLSCs), is indoleamine-2,3-dioxygenase-1 (IDO-1) which is upregulated by inflammatory stimuli, like cytokines. However, there are no data concerning continuing IDO-1 expression in hPDLSCs after the removal of inflammatory stimuli, such as cytokines and toll-like receptor (TLR) agonist-2 and TLR-3. Hence, primary hPDLSCs were stimulated with interleukin (IL)-1β, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, TLR-2 agonist Pam3CSK4 or TLR-3 agonist Poly I/C. IDO-1 gene and protein expression and its enzymatic activity were measured up to five days after removing any stimuli. IL-1β- and TNF-α-induced IDO-1 expression and enzymatic activity decreased in a time-dependent manner after cessation of stimulation. IFN-γ caused a long-lasting effect on IDO-1 up to five days after removing IFN-γ. Both, TLR-2 and TLR-3 agonists induced a significant increase in IDO-1 gene expression, but only TLR-3 agonist induced significantly higher IDO-1 protein expression and enzymatic activity in conditioned media (CM). IDO-1 activity of Poly I/C- and Pam3CSK4-treated hPDLSCs was higher at one day after removal of stimuli than immediately after stimulation and declined to basal levels after five days. Among all tested stimuli, only IFN-γ was able to induce long-lasting IDO-1 expression and activity in hPDLSCs. The high plasticity of IDO-1 expression and its enzymatic activity in hPDLSCs due to the variable cytokine and virulence factor milieu and the temporal-dependent responsiveness of hPDLSCs may cause a highly dynamic potential of hPDLSCs to modulate immune responses in periodontal tissues.

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The Augmented Productions of Neopterin and Cytokines from Macrophages/monocytes in vitro

Pteridines ◽

10.1515/pteridines.1996.7.3.72 ◽

1996 ◽

Vol 7 (3) ◽

pp. 72-76

Author(s):

Tadashi Lizuka ◽

Mitsuyo Sasaki ◽

Hitomi Kamisako ◽

Ko Oishi ◽

Shigeru Uemura ◽

...

Keyword(s):

Kawasaki Disease ◽

Interleukin 1 ◽

Poly I:C ◽

Recombinant Interferon ◽

Preliminary Examination ◽

Tnf Α ◽

Ifn Γ ◽

Factor Α ◽

Necrosis Factor

Summary In Kawasaki disease patients, increases in excretion of urinary neopterin coincided with fever and monocytosis in peripheral blood. We examined the products of neopterin, tumor necrosis factor-α (TNFα) and Interleukin-1 β (1L-1β) from healthy adult macrophages/monocytes (Mφ>/M), after stimulation with several activators to obtain some understanding of Kawasaki disease. Upon stimulation with either lipopolysaccharide (LPS) or polyinosinate-polycytidylate (Poly I:C), the Mφ/M released neopterin and pyogenic products (TNF-α or 1L-1β). The release of neopterin was eliminated by the addition of the anti-interferon-y antibody. The production of both TNF-α, 1L-1β and neopterin from Mφ/M upon stimulation of LPS was augmented in a co-culture with low dose recombinant interferon-y (rIFN-γ). Upon stimulation with rIFN-γ alone, however, the Mφ/M released neopterin but not the pyogenic products. A preliminary examination failed to detect. any difference in the response of the Mφ/M in adults annd children after stimulation with LPS. We concluded that some endotoxins could trigger the onset of Kawasaki disease and that endogenous IFN-γ can play an important role in the abnormality of Kawasaki disease patients

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l-Arginine Availability Regulates Inducible Nitric Oxide Synthase-Dependent Host Defense against Helicobacter pylori

Infection and Immunity ◽

10.1128/iai.00578-07 ◽

2007 ◽

Vol 75 (9) ◽

pp. 4305-4315 ◽

Cited By ~ 74

Author(s):

Rupesh Chaturvedi ◽

Mohammad Asim ◽

Nuruddeen D. Lewis ◽

Holly M. Scott Algood ◽

Timothy L. Cover ◽

...

Keyword(s):

Nitric Oxide ◽

Helicobacter Pylori ◽

Protein Expression ◽

Translation Initiation Factor ◽

No Production ◽

Dependent Manner ◽

Inos Protein ◽

Inos Protein Expression ◽

H Pylori ◽

Inducible Nitric Oxide

ABSTRACT Helicobacter pylori infection of the stomach causes an active immune response that includes stimulation of inducible nitric oxide (NO) synthase (iNOS) expression. Although NO can kill H. pylori, the bacterium persists indefinitely, suggesting that NO production is inadequate. We determined if the NO derived from iNOS in macrophages was dependent on the availability of its substrate, l-arginine (l-Arg). Production of NO by H. pylori-stimulated RAW 264.7 cells was dependent on the l-Arg concentration in the culture medium, and the 50% effective dose for l-Arg was 220 μM, which is above reported plasma l-Arg levels. While iNOS mRNA induction was l-Arg independent, iNOS protein increased in an l-Arg-dependent manner that did not involve changes in iNOS protein degradation. l-Lysine, an inhibitor of l-Arg uptake, attenuated H. pylori-stimulated iNOS protein expression, translation, NO levels, and killing of H. pylori. While l-Arg starvation suppressed global protein translation, at concentrations of l-Arg at which iNOS protein was only minimally expressed in response to H. pylori, global translation was fully restored and eukaryotic translation initiation factor α was dephosphorylated. H. pylori lacking the gene rocF, which codes for a bacterial arginase, induced higher levels of NO production by increasing iNOS protein levels. When murine gastric macrophages were activated with H. pylori, supraphysiologic levels of l-Arg were required to permit iNOS protein expression and NO production. These findings indicate that l-Arg is rate limiting for iNOS translation and suggest that the levels of l-Arg that occur in vivo do not permit sufficient NO generation by the host to kill H. pylori.

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A redox-based mechanism for induction of interleukin-1 production by nitric oxide in a human colonic epithelial cell line (HT29-Cl.16E)

Biochemical Journal ◽

10.1042/bj3130035 ◽

1996 ◽

Vol 313 (1) ◽

pp. 35-38 ◽

Cited By ~ 10

Author(s):

Geneviève VALLETTE ◽

Anne JARRY ◽

Jean-Eric BRANKA ◽

Christian L. LABOISSE

Keyword(s):

Nitric Oxide ◽

Epithelial Cell ◽

Cell Line ◽

Interleukin 1 ◽

Epithelial Cell Line ◽

Dependent Manner ◽

Colonic Epithelial Cell ◽

Colonic Epithelial Cell Line ◽

Dose Dependent ◽

Human Colonic Epithelial Cell

We evaluated the effects of two NO donors, sodium nitroprusside (SNP) and 3-morpholino-sydnonimine (SIN-1), characterized by alternative redox states, i.e. nitrosonium ion (NO+) and nitric oxide (NO•) respectively, on intracellular interleukin-1 (IL-1) production, by a human colonic epithelial cell line (HT29-Cl.16E). SNP was able to induce intracellular IL-1α production up to 10 h incubation, in a dose-dependent manner. Several experiments provide evidence that the NO+ redox form, and not the free radical NO•, is implicated in the IL-1α production: (i) SIN-1, devoid of any NO+ character, led to a very weak IL-1 production as compared with SNP; (ii) the reductive action of a thiol such as cysteine on NO+ led to a dose-dependent increase in NO• concentration, measured as NO2-/NO3- accumulation, and to a large decrease in IL-1 production. Dibutyryl cGMP had no effect on IL-1 production, this finding supporting the concept that a cGMP-independent pathway is involved in the intracellular signalling of NO+. Together these results point out that NO, depending on its redox form, is able to modulate IL-1 production in cultured colonic epithelial cells.

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Interferon-y-Induced Growth Inhibition of Neuroblastoma Cells is Independent of Induction of Nitric Oxide Synthase and Indoleamine 2,3-dioxygenase

Pteridines ◽

10.1515/pteridines.2004.15.3.91 ◽

2004 ◽

Vol 15 (3) ◽

pp. 91-96

Author(s):

Stephan Leitner ◽

Georg Golderer ◽

Christiana Winkler ◽

Dietmar Fuchs ◽

Gabriele Werner-Felmayer ◽

...

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Growth Inhibition ◽

Neuroblastoma Cell ◽

Neuroblastoma Cells ◽

Human Neuroblastoma Cell ◽

Human Neuroblastoma ◽

Indoleamine 2,3 Dioxygenase ◽

Ifn Γ ◽

Oxide Synthase

AbstractWe investigated a possible involvement of nitric oxide formed by inducible nitric oxide synthase (iNOS) in the signaling cascade leading to growth inhibition and differentiation in the human neuroblastoma cell line SK-NSII. Treatment of SK-N-SH with interferon-γ (IFN-γ) plus interleukin-lß (IL-lß) led to induction of iNOS, growth inhibition and an altered cell shape. However two inhibitors of iNOS were not able to prevent cytokine induced changes. In addition, IFN-γ alone led to growth inhibition in absence of iNOS induction. Inhibition of the induced indoleamine 2,3-dioxygenase (IDO) activity also did not prevent growth inhibition. Our findings show that mechanisms other than NO and IDO can control interferon-y-induced growth inhibition of SK-N-SH cells.

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Methanol Extract ofArtemisia apiaceaHance Attenuates the Expression of Inflammatory Mediators via NF-κB Inactivation

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/494681 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 9

Author(s):

Ji Choul Ryu ◽

Sang Mi Park ◽

Min Hwangbo ◽

Sung Hui Byun ◽

Sae Kwang Ku ◽

...

Keyword(s):

Nitric Oxide ◽

Therapeutic Potential ◽

Interleukin 1 ◽

Dependent Manner ◽

Nuclear Factor ◽

Paw Edema ◽

Concentration Dependent Manner ◽

Proinflammatory Mediators ◽

Inducible Nitric Oxide

Artemisia apiaceaHance is one of the most widely used herbs for the treatment of malaria, jaundice, and dyspeptic complaint in oriental medicine. This study investigated the effects of methanol extracts ofA. apiaceaHance (MEAH) on the induction of inducible nitric oxide synthase (iNOS) and proinflammatory mediators by lipopolysaccharide (LPS) in Raw264.7 macrophage cells and also evaluated thein vivoeffect of MEAH on carrageenan-induced paw edema in rats. MEAH treatment in Raw264.7 cells significantly decreased LPS-inducible nitric oxide production and the expression of iNOS in a concentration-dependent manner, while MEAH (up to 100 μg/mL) had no cytotoxic activity. Results from immunoblot analyses and ELISA revealed that MEAH significantly inhibited the expression of cyclooxygenase-2, tumor necrosis factor-α, interleukin-1β, and interleukin-6 in LPS-activated cells. As a plausible molecular mechanism, increased degradation and phosphorylation of inhibitory-κBαand nuclear factor-κB accumulation in the nucleus by LPS were partly blocked by MEAH treatment. Finally, MEAH treatment decreased the carrageenan-induced formation of paw edema and infiltration of inflammatory cells in rats. These results demonstrate that MEAH has an anti-inflammatory therapeutic potential that may result from the inhibition of nuclear factor-κB activation, subsequently decreasing the expression of proinflammatory mediators.

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Aspirin Protected the Nitric Oxide/Cyclic Gmp Generating System in Human Peritoneum

Peritoneal Dialysis International ◽

10.1177/089686080102103s08 ◽

2001 ◽

Vol 21 (3_suppl) ◽

pp. 48-53 ◽

Cited By ~ 1

Author(s):

Maria M. Arriero ◽

Angel Celdran ◽

Petra Jimenez ◽

Antonio García–Mendez ◽

Juan C. De La Pinta ◽

...

Keyword(s):

Nitric Oxide ◽

Protein Expression ◽

Soluble Guanylate Cyclase ◽

Dependent Manner ◽

Enos Expression ◽

Tissue Samples ◽

Peritoneal Tissue ◽

Capillary Endothelial Cells ◽

Anti Inflammatory ◽

Enos Protein

♦ Objective Changes in the expression of endothelial nitric oxide synthase (eNOS) in the peritoneum could be involved in the peritoneal dysfunction associated with peritoneal inflammation. The aim of the present study was to analyze the effect of Escherichia coli lipopolysaccharide (LPS) on eNOS expression in samples of human peritoneum. The effect of aspirin, a drug with anti-inflammatory properties, was also determined. ♦ Results The eNOS protein expressed in human peritoneal tissue was reduced by LPS (10 μg/mL) in a time-dependent manner. The eNOS was expressed mainly in capillary endothelial cells and mesothelial cells. Anti-inflammatory doses of aspirin (1 – 10 mmol/L) restored eNOS expression in LPS-stimulated human peritoneal tissue samples. The main intracellular receptor of NO, soluble guanylate cyclase (sGC), was also downregulated by LPS. This effect was prevented by aspirin (5 mmol/L). ♦ Conclusion Protein expression of the eNOS–sGC system in the peritoneal tissue was downregulated by LPS. High doses of aspirin protected both eNOS protein expression and sGC in human peritoneum. These findings suggest a new mechanism of action of aspirin that could be involved in the prevention of peritoneal dysfunction during inflammation.

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Plasmin potentiates induction of nitric oxide synthesis by interleukin-1 beta in vascular smooth muscle cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.264.2.h617 ◽

1993 ◽

Vol 264 (2) ◽

pp. H617-H624 ◽

Cited By ~ 6

Author(s):

W. Durante ◽

V. B. Schini ◽

S. Catovsky ◽

M. H. Kroll ◽

P. M. Vanhoutte ◽

...

Keyword(s):

Nitric Oxide ◽

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Culture Media ◽

Interleukin 1 ◽

Muscle Cells ◽

Dependent Manner ◽

Interleukin 1 Beta

Experiments were performed to examine the effect of the major fibrinolytic protease, plasmin, on the production of nitric oxide from interleukin-1 beta (IL-1 beta)-treated cultured human and rat aortic smooth muscle cells. Incubation of vascular smooth muscle cells with IL-1 beta resulted in significant accumulation of nitrite and nitrate in the culture media. Plasmin, either added exogenously or generated by the reaction of tissue plasminogen activator with plasminogen, potentiated the IL-1 beta-mediated release of nitrite and nitrate from smooth muscle cells in a concentration-dependent manner, without affecting the production of nitrite and nitrate from cells untreated with IL-1 beta. This potentiating effect was abolished when plasmin was incubated with the protease inhibitor, alpha 2-antiplasmin. The perfusates from columns containing IL-1 beta-treated smooth muscle cells relaxed detector blood vessels without endothelium, and the addition of IL-1 beta-treated smooth muscle cells to suspensions of indomethacin-treated platelets inhibited their aggregation. Untreated smooth muscle cells or cells treated with plasmin alone did not have such effects. However, the simultaneous treatment of smooth muscle cells with IL-1 beta and plasmin markedly enhanced both the relaxing activities of the perfusates and the inhibition of platelet aggregation. Treatment of smooth muscle cells with NG-nitro-L-arginine inhibited the cytokine-mediated effects as well as the potentiating effect of plasmin. These results demonstrate that the plasmin can enhance the production of nitric oxide by IL-1 beta-treated vascular smooth muscle cells.

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Bioactive Constituents from the Roots of Eurycoma longifolia

Molecules ◽

10.3390/molecules24173157 ◽

2019 ◽

Vol 24 (17) ◽

pp. 3157 ◽

Cited By ~ 10

Author(s):

Jingya Ruan ◽

Zheng Li ◽

Ying Zhang ◽

Yue Chen ◽

Mengyang Liu ◽

...

Keyword(s):

Nitric Oxide ◽

Protein Expression ◽

Raw264.7 Cells ◽

Dependent Manner ◽

Bioactive Constituents ◽

Spectral Techniques ◽

Eurycoma Longifolia ◽

Western Blot Method ◽

Phenolic Components ◽

Oxide Synthase

Four new phenolic components, eurylophenolosides A (1) and B (2), eurylolignanosides A (3) and B (4), along with twelve known compounds were isolated from the roots of Eurycoma longifolia Jack. The structure of these components was elucidated by using various spectral techniques and chemical reactions. Among the known isolates, syringaldehyde (12), 3-chloro-4-hydroxybenzoic acid (13), 3-chloro-4-hydroxyl benzoic acid-4-O-β-d-glucopyranoside (14), and isotachioside (15) were isolated from the Eurycoma genus for the first time. Further, the NMR data of 14 was reported here firstly. Meanwhile, the nitric oxide (NO) inhibitory activities of all compounds were examined in lipopolysaccharide (LPS)-stimulated RAW264.7 cells at 40 μM. As results, piscidinol A (6), 24-epi-piscidinol A (7), bourjotinolone A (10), and scopoletin (16) were found to play important role in suppressing NO levels without cytotoxicity. Furthermore, the Western blot method was used to investigate the mechanism of compounds 6, 7, 10, and 16 by analysing the level of inflammation related proteins, such as inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in LPS-stimulated RAW264.7 cells. Consequently, compounds 6, 7, 10, and 16 were found to significantly inhibit LPS-induced protein expression of IL-6, NF-κB and iNOS in NF-κB signaling pathway. Moreover, it was found that the protein expression inhibitory effects of 6, 7, and 16 exhibited in a dose-dependent manner. The mechanism may be related to the inhibition of the iNOS expressions through suppressing the IL-6-induced NF-κB pathway.

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Tetrahydrobiopterin synthesis and inducible nitric oxide production in pulmonary artery smooth muscle

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1994.266.4.l455 ◽

1994 ◽

Vol 266 (4) ◽

pp. L455-L460 ◽

Cited By ~ 1

Author(s):

D. K. Nakayama ◽

D. A. Geller ◽

M. Di Silvio ◽

G. Bloomgarden ◽

P. Davies ◽

...

Keyword(s):

Nitric Oxide ◽

Smooth Muscle ◽

Pulmonary Artery ◽

De Novo ◽

Interleukin 1 ◽

No Production ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Pulmonary Artery Smooth Muscle ◽

Inducible Nitric Oxide

We recently reported (Am. J. Respir. Cell Mol. Biol. 7: 471-476, 1992) that a mixture of lipopolysaccharide (LPS) and cytokines produced a time-dependent increase in mRNA and protein expression of inducible nitric oxide synthase (iNOS) in cultured rat pulmonary artery smooth muscle cells (RPASM). In the current study we extend observations on regulation of iNOS in RPASM by showing that de novo synthesis of tetrahydrobiopterin (BH4) is critical for LPS and cytokine-induced NO production. A mixture of LPS and the cytokines gamma-interferon, interleukin-1 beta, and tumor necrosis factor-alpha increased steady-state levels of mRNA of GTP-cyclohydrolase-I (GTP-CH), the rate-limiting enzyme in BH4 biosynthesis. Levels of mRNA to GTP-CH became detectable by 4 h, with further increases at 24 h by Northern blot analysis and reverse-transcriptase polymerase chain reaction. Total intracellular biopterin levels, undetectable under basal conditions, increased after 24 h exposure to LPS and cytokines (to 32.3 +/- 0.8 pmol/mg protein). LPS and cytokine-induced NO production, determined by nitrite concentrations in the medium, was decreased in a concentration-dependent manner by the GTP-CH inhibitor, 2,4-diamino-6-hydroxypyrimidine (DAHP) at 24 h. DAHP also inhibited completely the LPS- and cytokine-induced accumulation of intracellular biopterins. Sepiapterin, which supplies BH4 through a salvage pathway independent of GTP-CH, reversed the effect of DAHP on LPS and cytokine-induced NO production.(ABSTRACT TRUNCATED AT 250 WORDS)

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