scholarly journals Inducible nitric oxide synthase gene deletion exaggerates MAPK-mediated cyclooxygenase-2 induction by inflammatory stimuli

2010 ◽  
Vol 299 (3) ◽  
pp. H613-H623 ◽  
Author(s):  
Brian D. Lamon ◽  
Rita K. Upmacis ◽  
Ruba S. Deeb ◽  
Hilal Koyuncu ◽  
David P. Hajjar
Keyword(s):  
Nitric Oxide ◽  
Atherosclerotic Lesion ◽  
No Synthase ◽  
No Production ◽  
Nitrite Production ◽  
Inflammatory Stimuli ◽  
Ifn Γ ◽  
Cox 2 ◽  
The Impact ◽  
Inducible Nitric Oxide

Cyclooxygenase (COX)-2 and inducible nitric oxide (NO) synthase (iNOS) are responsive to a wide array of inflammatory stimuli, have been localized to vascular smooth muscle cells (SMCs), and are intimately linked to the progression of vascular disease, including atherosclerotic lesion formation. We and others have shown that the production and subsequent impact of COX products appear to be correlative with the status of NO synthesis. This study examined the impact of inflammation-driven NO production on COX-2 expression in SMCs. Concurrent stimulation of quiescent rat aortic SMCs with lipopolysaccharide (LPS) and interferon (IFN)-γ increased COX-2, iNOS, and nitrite production. Pharmacological inhibition of NO synthase ( NG-monomethyl-l-arginine) concentration- and time-dependently magnified LPS + IFN-γ-mediated COX-2 mRNA and protein induction in a cGMP-independent manner. COX-2 induction was associated with activation of the ERK, p38, and JNK mitogen-activated protein kinase (MAPK) pathways. Interestingly, NO synthase inhibition enhanced ERK, p38, and to a lesser extent JNK phosphorylation but suppressed MAPK phosphatase (MKP)-1 induction in response to LPS + IFN-γ. Similarly, the exposure of SMCs from iNOS−/− mice to LPS + IFN-γ produced an enhancement of COX-2 induction, p38, and JNK phosphorylation and an attenuated upregulation of MKP-1 versus their wild-type counterparts. Taken together, our data indicate that NO, in part derived from iNOS, negatively regulates the immediate early induction of COX-2 in response to inflammatory stimuli.

scholarly journals Fasting-induced intestinal apoptosis is mediated by inducible nitric oxide synthase and interferon-γ in rat

2010 ◽  
Vol 298 (6) ◽  
pp. G916-G926 ◽  
Author(s):  
Junta Ito ◽  
Hiroyuki Uchida ◽  
Takayuki Yokote ◽  
Kazuo Ohtake ◽  
Jun Kobayashi
Keyword(s):  
Nitric Oxide ◽  
Protein Expression ◽  
Interferon Γ ◽  
No Synthase ◽  
Histological Evaluation ◽  
No Production ◽  
Ros Production ◽  
Nitrite Production ◽  
Ifn Γ

Nitric oxide (NO) is associated with intestinal apoptosis in health and disease. This study aimed to investigate the role of intestinal NO in the regulation of apoptosis during fasting in rats. Male Wistar rats were divided into two groups and subcutaneously injected with saline (SA) or aminoguanidine (AG), followed by fasting for 24, 48, 60, and 72 h. At each time point, the jejunum was subjected to histological evaluation for enterocyte apoptosis by histomorphometric assessment and TUNEL analysis. We performed immunohistochemistry for inducible NO synthase (iNOS) expression in the jejunum and measured tissue nitrite levels using HPLC and 8-hydroxydeoxyguanosine adduct using ELISA, indicative of endogenous NO production and reactive oxygen species (ROS) production, respectively. Jejunal transcriptional levels of iNOS, neuronal NO synthase (nNOS), and interferon-γ (IFN-γ) were also determined by RT-PCR. Fasting caused significant jejunal mucosal atrophy due to attenuated cell proliferation and enhanced apoptosis with increase in iNOS transcription, its protein expression in intestinal epithelial cells (IEC), and jejunal nitrite levels. However, AG treatment histologically reduced apoptosis with inhibition of fasting-induced iNOS transcription, protein expression, and nitrite production. We also observed fasting-induced ROS production and subsequent IFN-γ transcription, which were all inhibited by AG treatment. Furthermore, we observed reduced transcriptional levels of nNOS, known to suppress iNOS activation physiologically. These results suggest that fasting-induced iNOS activation in IEC may induce apoptosis mediators such as IFN-γ via a ROS-mediated mechanism and also a possible role of nNOS in the regulation of iNOS activity in fasting-induced apoptosis.

Inducible nitric oxide synthase in the epithelial epididymal cells of the rat

1997 ◽  
Vol 9 (8) ◽  
pp. 789 ◽  
Author(s):  
Barbara Wiszniewska ◽  
Rafal Kurzawa ◽  
Andrzej Ciechanowicz ◽  
Boguslaw Machalinski
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Epithelial Cells ◽  
Inducible Nitric Oxide Synthase ◽  
Cultured Cells ◽  
No Production ◽  
Nitrite Production ◽  
Oxide Synthase ◽  
Inducible Nos ◽  
Inducible Nitric Oxide

The expression of mRNA for inducible nitric oxide synthase (iNOS) in rat epithelial cells of epididymis was investigated with reverse transcription followed by polymerase chain reaction. Immunocytochemical reaction for iNOS was performed to confirm the enzyme’ s localization in the epididymal epithelium. Additionally, an indirect spectrophotometric method for nitric oxide (NO) determination was applied for measurement of nitrite production by cultured epididymal epithelial cells. Inducible NOS mRNA was detected in freshly isolated epithelial cells, in cultured cells without stimulation as well as in cultured cells after stimulation by lipopolysaccharide and interferon-gamma. Inducible NOS immunoreactivity was observed in the apical part of epithelial cells of epididymal sections and in the cytoplasm of cells in culture. Release of nitrite was observedin vitro in both the unstimulated and stimulated cells of caput (1·44 ± 0·94 v. 4·37 ± 2·42 µM) and cauda (0·69 ± 1·21 v. 5·21 ± 2·76 µM) epididymis (P < 0·001). To the best of our knowledge, this is the first study to demonstrate iNOS in the epididymal epithelial cells of the rat. Nitric oxide released by epididymal epithelial cells may act on cells and tissues located nearby. The results may help explain epididymal function: sperm storage, passage and maturation. Excessive epididymal NO production may also play a role in the inflammatory infertility of the male. Extra keyword: iNOS

Angiotensin II receptor subtypes determine induced NO production in rat glomerular mesangial cells

2000 ◽  
Vol 279 (6) ◽  
pp. F1092-F1100 ◽  
Author(s):  
Jörg Schwöbel ◽  
Tina Fischer ◽  
Bettina Lanz ◽  
Markus Mohaupt
Keyword(s):  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Mesangial Cells ◽  
Receptor Expression ◽  
Receptor Subtypes ◽  
No Production ◽  
Ang Ii ◽  
Glomerular Mesangial Cells ◽  
Nitrite Production ◽  
The Impact

Angiotensin II (ANG II) and nitric oxide (NO) have contrasting vascular effects, yet both sustain inflammatory responses. We investigated the impact of ANG II on lipopolysaccharide (LPS)/interferon-γ (IFN)-induced NO production in cultured rat mesangial cells (MCs). LPS/IFN-induced nitrite production, the inducible form of nitric oxide synthase (NOS-2) mRNA, and protein expression were dose dependently inhibited by ANG II on coincubation, which was abolished on ANG II type 2 (AT2) receptor blockade by PD-123319. Homology-based RT-PCR verified the presence of AT1A, AT1B, and AT2 receptors. To shift the AT receptor expression toward the type 1 receptor, two sets of experiments were performed: LPS/IFN preincubation for 24 h was followed by 8-h coincubation with ANG II; or during 24-h coincubation of LPS/IFN and ANG II, dexamethasone was added for the last 6-h period. Both led to an amplified overall expression of NOS-2 protein and NO production that was inhibitable by actinomycin D in the first setup. Induced NO production was enhanced via the AT1 receptor; however, it was diminished via the AT2 receptor. In conclusion, induced NO production is negatively controlled by the AT2, whereas AT1 receptor stimulation enhanced NO synthesis in MCs. The overall NO availability depended on the onset of the inflammatory stimuli with respect to ANG II exposure and the available AT receptors.

Effect of corticosteroids on nitric oxide production in inflammatory bowel disease: are leukocytes the site of action?

2005 ◽  
Vol 288 (2) ◽  
pp. G261-G267 ◽  
Author(s):  
John D. Linehan ◽  
George Kolios ◽  
Vassilis Valatas ◽  
Duncan A. F. Robertson ◽  
John Westwick
Keyword(s):  
Nitric Oxide ◽  
Ulcerative Colitis ◽  
Mononuclear Cells ◽  
Intestinal Inflammation ◽  
Inos Mrna ◽  
No Production ◽  
Nitrite Production ◽  
Ifn Γ ◽  
Colonic Biopsies ◽  
Ht 29

Nitric oxide (NO) production is increased in the human colonic mucosa in intestinal inflammation. We examined the effect of corticosteroids and the role of mononuclear cells in this production. Colonic biopsies from patients with ulcerative colitis and normal controls were cultured with either budesonide or prednisolone in the presence of proinflammatory cytokines. Human mixed mononuclear cells (MMCs) were cocultured with HT-29 cells stimulated with IFN-γ and LPS in the presence or absence of corticosteroids. Nitrite production was measured in supernatants by a modification of the Griess reaction, and inducible NO synthase (iNOS) mRNA expression was studied in colonic tissue by RT-PCR. Both steroids significantly suppressed the nitrite production and iNOS mRNA expression in inflamed colonic biopsies from ulcerative colitis patients and in cytokine-stimulated normal colonic biopsies but not in cytokine-stimulated HT-29 cells. Nitrite production by HT-29 cells was significantly increased ( P < 0.01) in cocultures with MMCs stimulated with IFN-γ and LPS. The presence of either prednisolone or budesonide significantly ( P < 0.01) suppressed nitrite production from cocultures of HT-29 cells and MMCs but not from cultures of HT-29 cells stimulated with conditioned media from activated MMCs. Interestingly, stimulation of HT-29 with conditioned media from MMCs pretreated with steroids before stimulation with LPS and IFN-γ induced a significantly ( P < 0.01) lower nitrite production. These results suggest that the inhibitory effect of corticosteroids on the NO production in the intestinal inflammation might be via the inhibition of MMC-produced mediators responsible for NO production by colonic epithelial cells.

scholarly journals Anti-inflammatory Activity of Constituents Isolated from Terminalia chebula

2014 ◽  
Vol 9 (7) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Min Hye Yang ◽  
Zulfiqar Ali ◽  
Ikhlas A. Khan ◽  
Shabana I. Khan
Keyword(s):  
Nitric Oxide ◽  
Cellular Level ◽  
Inflammatory Activity ◽  
No Production ◽  
Terminalia Chebula ◽  
Arjunolic Acid ◽  
Cox 2 ◽  
Anti Inflammatory ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

This study was aimed at the evaluation of the anti-inflammatory activity of twelve compounds isolated from the methanolic extract of fruits of Terminalia chebula. The activity was determined in terms of their ability to inhibit inducible nitric oxide synthase ( iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated macrophages. Two gallotannins [chebulinic acid (1) and 2,3,6-tri- O-galloyl-β-D-glucose (2)] and two triterpenoids [arjunic acid (3) and arjunolic acid (4)] efficiently reduced nitric oxide (NO) production with IC50 values of 53.4, 55.2, 48.8, and 38.0 μM, respectively. The protein expressions of iNOS and COX-2 were decreased in macrophages by treatment with compounds 1–4 (54–69% and 33–37%, respectively) at 50 μM. This is the first report of anti-inflammatory property of 1–4 mediated by inhibition of iNOS and COX-2 activities at the cellular level.

scholarly journals Inducible Nitric Oxide Synthase Can Be Induced in the Absence of Active Nuclear Factor-κB in Rat Mesangial Cells

1999 ◽  
Vol 10 (4) ◽  
pp. 721-729 ◽  
Author(s):  
OSAMU NAKASHIMA ◽  
YOSHIO TERADA ◽  
SEIJI INOSHITA ◽  
MICHIO KUWAHARA ◽  
SEI SASAKI ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mesangial Cells ◽  
Nuclear Factor Κb ◽  
Nitrite Production ◽  
Tnf Α ◽  
Inos Promoter ◽  
Ifn Γ ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide ◽  
Inos Induction

Abstract. The contribution of nuclear factor-κB (NF-κB) and interferon-γ (IFN-γ) signaling to nitric oxide generation is not completely understood. The effect of NF-κB release and its inhibition on nitrite production and the involvement of Janus kinase 2 (JAK2) in inducible nitric oxide synthase (iNOS) induction were investigated. The following assays were performed. (1) Nitrite produced by rat mesangial cells in primary culture was measured in incubations with tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS), with or without IFN-γ. Cells were stimulated with TNF-α or LPS plus IFN-γ in the presence of NF-κB inhibitors, herbimycin A (HerA), or the more specific JAK2 inhibitor AG490. (2) Immunoblotting was performed against the p65 and p50 subunits of NF-κB and iNOS. (3) Electrophoretic mobility shift assays were performed against NF-κB in the presence of NF-κB inhibitors or AG490. (4) iNOS promoter activity was measured in the presence of AG490 or JAK2 antisense oligonucleotides. TNF-α or LPS alone did not induce nitrite production, but with IFN-γ these compounds did induce nitrite production. Pyrrolidine dithiocarbamate (PDTC),N-acetyl-L-cysteine, dexamethasone (Dex), HerA, and AG490 partially inhibited LPS/IFN-γ- or TNF-α/IFN-γ-induced nitrite production. p65 was inhibited by the three NF-κB inhibitors described above, whereas p50 was not. PDTC and Dex completely inhibited the p65/p50 heterodimer, but HerA and AG490 had little effect on p65/p50. AG490 and JAK2 antisense oligonucleotides suppressed iNOS promoter activity. It can be concluded that (1) iNOS can be induced without active NF-κB; (2) Dex, acetylsalicylic acid, and PDTC inhibit only p65; and (3) JAK2 is involved in iNOS induction, and the contribution of JAK2 to nitrite production is greater than that of NF-κB.

Inducible Activity of Ginger Rhizome (Zingiber Offifinale Rosc.) on the mRNA Expression of Macrophage-Inducible Nitric Oxide (NO) Synthase and NO Production in a Macrophage Cell Line, RAW264.7 Cells

2004 ◽  
Vol 32 (05) ◽  
pp. 727-735 ◽  
Author(s):  
Nobuko Imanishi ◽  
Naoki Mantani ◽  
Shinya Sakai ◽  
Miyuki Sato ◽  
Yuko Katada ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mrna Expression ◽  
Cell Line ◽  
Kinetic Studies ◽  
No Synthase ◽  
Raw264.7 Cells ◽  
No Production ◽  
Macrophage Cell Line ◽  
Macrophage Cell ◽  
Inducible Nitric Oxide

We have investigated the effect of Zingiber offifinale Rosc. (ZOR) on macrophage-inducible nitric oxide (NO) synthase (macNOS) mRNA expression and NO production in RAW264.7 cells, a murine macrophage cell line; 100 μg/ml ZOR can induce macNOS mRNA expression, but induction effects at a dose below 10 μg/ml were weak or negligible. Kinetic studies showed that macNOS mRNA can be detected from 4 hours to 24 hours after dosing, with a peak at 8 hours. In accordance with the induction of macNOS mRNA expression, NO concentrations increased from 3.4 μM at 2 hours to almost 150 μM at 24 hours, reflecting a longer period of macNOS mRNA expression. The activity of ZOR can be considered to contribute, at least in part, to the beneficial effects of ZOR through the macNOS-mediated activation of the biodefense mechanism.

scholarly journals Kinetic modelling of the nitric oxide gradient generated in vitro by adherent cells expressing inducible nitric oxide synthase

1996 ◽  
Vol 314 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Michel LAURENT ◽  
Michel LEPOIVRE ◽  
Jean-Pierre TENU
Keyword(s):  
Nitric Oxide ◽  
Kinetic Modelling ◽  
No Synthase ◽  
Target Cells ◽  
No Production ◽  
Adherent Cells ◽  
True Rate ◽  
Neutral Radical ◽  
Inducible Nitric Oxide

Inducible nitric oxide (NO) synthase produces a long-lasting NO flux which can exert cytotoxic effects on target cells. A prerequisite for the understanding of the molecular basis of NO action is quantitative data on the availability of this small neutral radical molecule at both the spatial and temporal levels. The limits of NO availability depend on the respective rates of NO production, diffusion and autoxidation by molecular oxygen. Kinetic modelling of these processes has been performed for a widely used experimental system consisting of a monolayer of adherent cells cultured in vitro for hours in unstirred culture medium. It appears that: (i) the maximal NO concentration in the culture is in the immediate vicinity of the monolayer, where target cells will sediment; (ii) the steady-state NO concentration in this area is lower than 4 to 5 μM; and (iii) measurements of nitrite/nitrate or citrulline accumulation in the bulk cell medium culture during a given time period significantly underestimate (by a factor of up to 3 to 4) the true rate of NO synthesis at the level of the producer cell. This rate can be, nevertheless, easily estimated from the rate of production of the stable NO synthase products.

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