scholarly journals Dexamethasone differentially affects interleukin 1β- and cyclic AMP-induced nitric oxide synthase mRNA expression in renal mesangial cells

1994 ◽  
Vol 304 (2) ◽  
pp. 337-340 ◽  
Author(s):  
D Kunz ◽  
G Walker ◽  
J Pfeilschifter
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Cyclic Amp ◽  
Mesangial Cells ◽  
Inos Mrna ◽  
Mrna Levels ◽  
Necrosis Factor Alpha ◽  
Camp Analogue ◽  
Oxide Synthase ◽  
Inos Induction

Inducible nitric oxide synthase (iNOS) is expressed in renal mesangial cells in response to two principal classes of activating signals that interact in a synergistic fashion. These two groups of activators comprise inflammatory cytokines such as interleukin (IL)-1 beta or tumour necrosis factor alpha and agents that elevate cellular levels of cyclic AMP (cAMP). We examined whether dexamethasone differentially affects iNOS induction in response to IL-1 beta and a membrane-permeable cAMP analogue, N6,O-2′-dibutyryladenosine 3′,5′-phosphate (Bt2cAMP). Nanomolar concentrations of dexamethasone suppress IL-1 beta- as well as Bt2cAMP-induced iNOS protein expression and production of nitrite, the stable end product of nitric oxide (NO) formation. In contrast, dexamethasone prevents induction of iNOS mRNA in response to Bt2cAMP without affecting IL-1 beta-triggered increase in iNOS mRNA levels. These data suggest that dexamethasone acts at different levels, depending on the stimulus used to suppress iNOS induction in mesangial cells.

Induction of nitric oxide synthase in rat gastric smooth muscle preparations

1997 ◽  
Vol 273 (5) ◽  
pp. G1101-G1107 ◽  
Author(s):  
Xi-Long Zheng ◽  
Keith A. Sharkey ◽  
Morley D. Hollenberg
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Nitric Oxide Synthase ◽  
Time Course ◽  
Inos Mrna ◽  
Organ Bath ◽  
Relaxant Response ◽  
Oxide Synthase ◽  
Inos Induction

The induction in vitro of inducible nitric oxide synthase (iNOS) in intact gastric circular (CM) and longitudinal (LM) smooth muscle preparations was evaluated 1) pharmacologically, by the appearance of 1 mM l-arginine (l-Arg)-induced relaxation in a precontracted tissue; 2) biochemically, according to the appearance of iNOS mRNA using a reverse transcriptase-polymerase chain reaction; and 3) immunohistochemically, using an iNOS-specific antibody. Functionally, iNOS induction affected the contractile properties of the CM but not the LM preparation. The time course of iNOS induction monitored pharmacologically paralleled exactly the appearance of iNOS mRNA. The relaxant response to l-Arg in iNOS-induced CM tissues was blocked by the iNOS inhibitor aminoguanidine and by the guanylyl cyclase inhibitor LY-83583. The addition of oxyhemoglobin to the organ bath also attenuated the relaxant response, but tetrodotoxin had no effect. The transcriptional inhibitor actinomycin D completely blocked iNOS induction as assessed by both pharmacological and biochemical criteria. In iNOS-induced preparations the iNOS immunoreactivity was not detected in the smooth muscle elements but was localized in a layer of macrophage-related cells that were in apposition to the CM smooth muscle elements. We conclude that the spontaneous induction of iNOS in rat gastric tissue can affect the pharmacomechanical reactivity of the CM elements and that this regulation of the CM contractility is due to the induction of iNOS in a set of macrophage-related cells that are closely apposed to the CM elements so that they selectively affect only the contractility of the CM preparation.

scholarly journals Interleukin-13 inhibits inducible nitric oxide synthase expression in human mesangial cells

1996 ◽  
Vol 313 (2) ◽  
pp. 641-646 ◽  
Author(s):  
Marta SAURA ◽  
Rosa MARTÍNEZ-DALMAU ◽  
Adrian MINTY ◽  
Dolores PÉREZ-SALA ◽  
Santiago LAMAS
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Mesangial Cells ◽  
Inhibitory Effect ◽  
Northern Analysis ◽  
Inos Mrna ◽  
Dependent Manner ◽  
Human Mesangial Cells ◽  
Oxide Synthase ◽  
Stimulation Of

The synthesis of nitric oxide in inflammatory situations requires the expression of an inducible isoform of nitric oxide synthase (iNOS). Human mesangial cells (HMC) express an iNOS enzyme after exposure to multiple co-stimuli. In this study we have observed that while tumour necrosis factor-α, interleukin (IL)-1β, interferon-γ and bacterial lipopolysaccharide (LPS) were unable to significantly induce NO synthesis when used alone, they induced an evident stimulation of NO synthesis when used in various combinations. A mixture of the three cytokines (CM) and LPS resulted in a 10-15-fold stimulation of NO synthesis over control values which started to be significant after 16 h. The addition of IL-13, a cytokine with anti-inflammatory properties, inhibited CM/LPS-induced NO synthesis in a concentration-dependent manner. A marked inhibitory effect (60-65%) could be observed when HMC were treated with IL-13 (10 ng/ml) 24 h before, at the same time as, or even 4 h after the addition of CM/LPS. This inhibitory effect was still significant (25%) when IL-13 was added 16 h after CM/LPS. Northern analysis showed that IL-13-mediated iNOS inhibition was closely correlated with the suppression of iNOS mRNA expression. These results identify IL-13 as a powerful regulatory tool for the inhibition of NO synthesis in human cells, a property which may be pathophysiologically relevant in NO-related inflammatory processes.

scholarly journals Differential regulation of nitric oxide synthase mRNA expression by lipopolysaccharide and pro-inflammatory cytokines in fetal hepatocytes treated with cycloheximide

1997 ◽  
Vol 327 (3) ◽  
pp. 819-823 ◽  
Author(s):  
Marta CASADO ◽  
María J. M DÍAZ-GUERRA ◽  
Lisardo BOSCÁ ◽  
Paloma MARTÍN-SANZ
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Mrna Expression ◽  
Inflammatory Cytokines ◽  
Inos Mrna ◽  
Mrna Levels ◽  
Mobility Shift ◽  
Fetal Hepatocytes ◽  
Oxide Synthase ◽  
Pro Inflammatory Cytokines

The effect of cycloheximide (CHX) on the mRNA expression of the cytokine-inducible, calcium-independent nitric oxide synthase (iNOS) was investigated in fetal hepatocytes stimulated with lipopolysaccharide (LPS) or pro-inflammatory cytokines. In the presence of CHX the LPS-dependent iNOS mRNA levels were reduced, whereas the response to pro-inflammatory cytokines was enhanced. Because iNOS transcription is highly dependent on the activation of nuclear factor κB (NF-κB), this factor was evaluated by electrophoretic mobility shift assays, and a close correlation between NF-κB activity and iNOS mRNA levels was observed. CHX itself potentiated the degradation of the IκBα and IκBβ inhibitory subunits (IκB is inhibitory κB) of the NF-κB complex, and therefore the loss of LPS-dependent iNOS mRNA expression cannot be attributed to a blockage in the activation of NF-κB. These results suggest the existence of a CHX-sensitive pathway in the expression of iNOS mediated by LPS, a mechanism that is not involved in the response to pro-inflammatory cytokines.

Inhibition of inducible nitric oxide synthesis by the herbal preparation Padma 28 in macrophage cell line

2000 ◽  
Vol 78 (11) ◽  
pp. 861-866 ◽  
Author(s):  
Thomas Moeslinger ◽  
Roswitha Friedl ◽  
Ivo Volf ◽  
Monika Brunner ◽  
Elisabeth Koller ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Inos Mrna ◽  
Mrna Levels ◽  
Nitric Oxide Synthesis ◽  
Mouse Macrophages ◽  
Oxide Synthase ◽  
Padma 28 ◽  
Inducible Nitric Oxide

Padma 28 is a mixture of herbs used in traditional Tibetan medicine with anti-inflammatory activities. We investigated the effects of Padma 28 on nitric oxide (NO) production by the inducible nitric oxide synthase (iNOS) in lipopolysaccharide stimulated mouse macrophages (RAW 264.7). Padma 28 (0-900 µg/mL) induced a concentration dependent inhibition of inducible nitric oxide synthesis. iNOS protein expression showed a concentration dependent reduction as revealed by immunoblotting when cells were incubated with increasing amounts of Padma 28. Padma 28 decreased iNOS mRNA levels as shown by RT-PCR. Aqueous extracts from costi amari radix (costus root, the dried root of Saussurea lappa) and the outer cover of myrobalani fructus (the dried fruit of Terminalia chebula), constituents of the complex herb preparation Padma 28, were found to inhibit inducible nitric oxide synthesis by decreasing iNOS protein and iNOS mRNA levels. The inhibition of inducible nitric oxide synthesis might contribute to the anti-inflammatory activities of Padma 28.Key words: inducible nitric oxide synthase, mouse macrophages, myrobalans, radix costae.

scholarly journals Expression and Bactericidal Activity of Nitric Oxide Synthase in Brucella suis-Infected Murine Macrophages

1998 ◽  
Vol 66 (4) ◽  
pp. 1309-1316 ◽  
Author(s):  
Antoine Gross ◽  
Sandra Spiesser ◽  
Annie Terraza ◽  
Bruno Rouot ◽  
Emmanuelle Caron ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Mouse Serum ◽  
Inos Mrna ◽  
Necrosis Factor Alpha ◽  
Murine Macrophages ◽  
Tnf Α ◽  
Brucella Suis ◽  
Ifn Γ ◽  
Oxide Synthase

ABSTRACT We examined the expression and activity of inducible nitric oxide synthase (iNOS) in both gamma interferon (IFN-γ)-treated and untreated murine macrophages infected with the gram-negative bacteriumBrucella suis. The bacteria were opsonized with a mouse serum containing specific antibrucella antibodies (ops-Brucella) or with a control nonimmune serum (c-Brucella). The involvement of the produced NO in the killing of intracellular B. suis was evaluated. B. suis survived and replicated within J774A.1 cells. Opsonization with specific antibodies increased the number of phagocytized bacteria but lowered their intramacrophage development. IFN-γ enhanced the antibrucella activity of phagocytes, with this effect being greater inops-Brucella infection. Expression of iNOS, interleukin-6, and tumor necrosis factor alpha (TNF-α) mRNAs was induced in bothc-Brucella- and ops-Brucella-infected cells and was strongly potentiated by IFN-γ. In contrast to that of cytokine mRNAs, iNOS mRNA expression was independent of opsonization. Similar levels of iNOS mRNAs were expressed in IFN-γ-treated cells infected with c-Brucella or ops-Brucella; however, expression of iNOS protein and production of NO were detected only in IFN-γ-treated cells infected with ops-Brucella. These discrepencies between iNOS mRNA and protein levels were not due to differences in TNF-α production. The iNOS inhibitorNω-nitro-l-arginine methyl ester increasedB. suis multiplication specifically in IFN-γ-treated cells infected with ops-Brucella, demonstrating a microbicidal effect of the NO produced. This observation was in agreement with in vitro experiments showing that B. suiswas sensitive to NO killing. Together our data indicate that inB. suis-infected murine macrophages, the posttranscriptional regulation of iNOS necessitates an additive signal triggered by macrophage Fcγ receptors. They also support the possibility that in mice, NO favors the elimination ofBrucella, providing that IFN-γ and antibrucella antibodies are present, i.e., following expression of acquired immunity.

Interleukin-1β, Src- and non-Src tyrosine kinases, and nitric oxide synthase induction in rat aorta in vitro

2000 ◽  
Vol 279 (2) ◽  
pp. H566-H576 ◽  
Author(s):  
Yu Gui ◽  
Xi-Long Zheng ◽  
Morley D. Hollenberg
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Tyrosine Kinases ◽  
Rat Aorta ◽  
Interleukin 1Β ◽  
Inos Mrna ◽  
Src Tyrosine Kinases ◽  
Oxide Synthase ◽  
Inos Induction

We studied the potential roles for endogenous interleukin-1β (IL-1β) and for several signaling pathways in the spontaneous induction in vitro of inducible nitric oxide synthase (iNOS) in endothelium-denuded rat aorta rings. Added IL-1β augmented, whereas the IL-1β receptor antagonist IL-1ra blocked, spontaneous iNOS induction. Furthermore, increases in IL-1β mRNA preceded those of iNOS mRNA. Mitogen-activated protein kinase kinase and phosphatidyl inositol 3′ kinase inhibition did not block iNOS induction, whereas nuclear factor κB inhibition did. The sarcoma virus tyrosine kinase (Src) family-selective inhibitor 4-amino-5(4-methylphenyl)-7-( t-butyl)pyrazolo[3,4-d]pyrimidine (PP1) blocked the upregulation of IL-1β mRNA and the subsequent induction of iNOS but not the induction of iNOS stimulated by exogenously added IL-1β. In contrast, the non-Src inhibitors TP 47/AG 213 and genistein and the tyrosine phosphatase inhibitor vanadate did not affect the spontaneous upregulation of IL-1β mRNA but blocked both the IL-1β-mediated and spontaneous induction of iNOS. We conclude that 1) the upregulation of tissue IL-1β, via a signaling pathway involving a Src family kinase, plays a key role in rat vascular iNOS induction and 2) non-Src tyrosine kinases play roles downstream from IL-1β for iNOS induction.

Inducible nitric oxide synthase subserves cholinergic vasodilation in retina

2005 ◽  
Vol 22 (3) ◽  
pp. 371-377 ◽  
Author(s):  
ALEJANDRO BERRA ◽  
SABRINA GANZINELLI ◽  
MARIO SARAVIA ◽  
ENRI BORDA ◽  
LEONOR STERIN-BORDA
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Retinal Vessel ◽  
Inos Mrna ◽  
Mrna Levels ◽  
Mrna Gene ◽  
Oxide Synthase ◽  
Mrna Gene Expression ◽  
Stimulation Of

In this paper, we investigate the role of muscarinic acetylcholine receptor (mAChR) activity in the regulation of inducible (i) nitric oxide synthase (iNOS) expression and activity. The signaling pathway involved is also examined. These experiments also provide a link between mAChR activation and the nitric oxide (NO)-dependent regulation of retinal vascular diameter. The diameter of the retinal vessels at a distance of 1 disc diameter from the center of the optic disc was measured in rats using digital retinal photography, and both iNOS-mRNA gene expression and NOS were specifically measured using RT-PCR and [U-14C] citrulline assays, respectively. Stimulation of M1 and M3 mAChR with carbachol caused an increase in vessel diameter, in iNOS-mRNA levels and in NOS activity in the retina. Aminoguanidine, an inhibitor of iNOS, attenuated all these effects. Inhibitors of phospholipase C (PLC) and protein kinase C (PKC) but not calcium/calmodulin (CaM) prevented the muscarinic-dependent increase in iNOS-mRNA levels. The results obtained suggest that the activation of mAChR increases retinal vessel diameters by increasing the production of nitric oxide (NO) through iNOS activation and iNOS-mRNA gene expression. The mechanism appears to occur secondarily to stimulation of PLC and PKC enzymatic activity.

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