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 Comparing the protective effects of resveratrol, curcumin and sulforaphane against LPS/IFN-γ-mediated inflammation in doxorubicin-treated macrophages

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haidy A. Saleh ◽  
Eman Ramdan ◽  
Mohey M. Elmazar ◽  
Hassan M. E. Azzazy ◽  
Anwar Abdelnaser
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Response ◽  
Raw 264.7 Cells ◽  
Inos Mrna ◽  
No Production ◽  
Raw 264.7 ◽  
Mrna Levels ◽  
Protective Effects ◽  
Tnf Α ◽  
Ifn Γ

AbstractDoxorubicin (DOX) chemotherapy is associated with the release of inflammatory cytokines from macrophages. This has been suggested to be, in part, due to DOX-mediated leakage of endotoxins from gut microflora, which activate Toll-like receptor 4 (TLR4) signaling in macrophages, causing severe inflammation. However, the direct function of DOX on macrophages is still unknown. In the present study, we tested the hypothesis that DOX alone is incapable of stimulating inflammatory response in macrophages. Then, we compared the anti-inflammatory effects of curcumin (CUR), resveratrol (RES) and sulforaphane (SFN) against lipopolysaccharide/interferon-gamma (LPS/IFN-γ)-mediated inflammation in the absence or presence of DOX. For this purpose, RAW 264.7 cells were stimulated with LPS/IFN-γ (10 ng/mL/10 U/mL) in the absence or presence of DOX (0.1 µM). Our results showed that DOX alone is incapable of stimulating an inflammatory response in RAW 264.7 macrophages. Furthermore, after 24 h of incubation with LPS/IFN-γ, a significant increase in tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS) mRNA levels was observed. Similarly, nitric oxide (NO) production and TNF-α and IL-6 protein levels were significantly upregulated. Moreover, in LPS/IFN-γ-treated macrophages, the microRNAs (miRNAs) miR-146a, miR-155, and miR-21 were significantly overexpressed. Interestingly, upon testing CUR, RES, and SFN against LPS/IFN-γ-mediated inflammation, only SFN was able to significantly reverse the LPS/IFN-γ-mediated induction of iNOS, TNF-α and IL-6 and attenuate miR-146a and miR-155 levels. In conclusion, SFN, at the transcriptional and posttranscriptional levels, exhibits potent immunomodulatory action against LPS/IFN-γ-stimulated macrophages, which may indicate SFN as a potential treatment for DOX-associated inflammation.

scholarly journals Acquired interferon γ responsiveness during Caco-2 cell differentiation: effects on iNOS gene expression

Gut ◽  
1999 ◽  
Vol 44 (5) ◽  
pp. 659-665 ◽  
Author(s):  
A M Chavez ◽  
M J Morin ◽  
N Unno ◽  
M P Fink ◽  
R A Hodin
Keyword(s):  
Nitric Oxide ◽  
Cell Differentiation ◽  
Interferon Γ ◽  
Intestinal Barrier Function ◽  
Inos Mrna ◽  
Pyrrolidine Dithiocarbamate ◽  
No Production ◽  
Mrna Induction ◽  
Ifn Γ ◽  
Inos Induction

BACKGROUNDImpairment of intestinal barrier function occurs under a variety of inflammatory conditions and is mediated at least in part by interferon γ (IFN-γ) induced nitric oxide (NO) production. Previous in vivo studies have shown that systemic lipopolysaccharide treatment caused an induction of the rat inducible nitric oxide synthase (iNOS) mRNA primarily in villus cells, rather than in undifferentiated crypt cells.AIMSTo examine iNOS induction by IFN-γ in vitro as a function of enterocyte differentiation.METHODSPreconfluent and postconfluent Caco-2 cells were treated with IFN-γ in the presence or absence of various inhibitors. Northern analyses were performed to assess the magnitude of iNOS mRNA induction. IFN-γ receptor mRNA and protein levels were determined.RESULTSiNOS mRNA induction by IFN-γ occurred at two hours and was not blocked by cycloheximide, indicating that it is an immediate early response. iNOS induction and nitrite/nitrate increases were inhibited by dexamethasone and pyrrolidine dithiocarbamate, supporting an important role for the NF-κB transcription factor in this process. The stimulated iNOS induction was seen almost exclusively under conditions of cellular differentiation—that is, in postconfluent Caco-2 cells. This increased IFN-γ responsiveness seen in postconfluent Caco-2 cells correlated with an increased expression of IFN-γ receptor, whereas T84 and HT-29 cells did not show any significant alterations in either iNOS induction or IFN-γ receptor levels as a function of postconfluent growth.CONCLUSIONSWith regard to iNOS mRNA induction, IFN-γ responsiveness is acquired during Caco-2 cell differentiation, perhaps related to an increase in the numbers of IFN-γ receptors.

scholarly journals Protective Role of Nitric Oxide inStaphylococcus aureus Infection in Mice

1998 ◽  
Vol 66 (3) ◽  
pp. 1017-1022 ◽  
Author(s):  
Sanae Sasaki ◽  
Tomisato Miura ◽  
Shinsuke Nishikawa ◽  
Kyogo Yamada ◽  
Mayuko Hirasue ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Spleen Cell ◽  
Cell Cultures ◽  
Protective Role ◽  
Inos Mrna ◽  
No Production ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACT This study was carried out to determine the role of nitric oxide (NO) in Staphylococcus aureus infection in mice. NO production in spleen cell cultures was induced by heat-killed S. aureus. Expression of mRNA of the inducible isoform of NO synthase (iNOS) was induced in the spleens and kidneys of S. aureus-infected mice. When mice were treated with monoclonal antibodies (MAbs) against tumor necrosis factor alpha (TNF-α) or gamma interferon (IFN-γ) before S. aureus infection, the induction of iNOS mRNA expression in the kidneys was inhibited. These MAbs also inhibited NO production in spleen cell cultures stimulated with heat-killed S. aureus. NO production in the spleen cell cultures and levels of urinary nitrate plus nitrite were suppressed by treatment with aminoguanidine (AG), a selective inhibitor of iNOS. The survival rates of AG-treated mice were significantly decreased by either lethal or sublethal S. aureusinfections. However, an effect of AG administration on bacterial growth was not observed in the spleens and kidneys of mice during either type of infection. Production of TNF-α and IFN-γ was not affected by AG treatment in vitro and in vivo. These results suggest that NO plays an important role in protection from lethality by the infection, but the protective role of NO in host resistance against S. aureusinfection was not proved. Moreover, our results show that TNF-α and IFN-γ regulate NO production while NO may not be involved in the regulation of the production of these cytokines during S. aureus infection.

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.

AVP inhibits LPS- and IL-1β-stimulated NO and cGMP via V1 receptor in cultured rat mesangial cells

1999 ◽  
Vol 276 (3) ◽  
pp. F433-F441 ◽  
Author(s):  
Tetsuo Umino ◽  
Eiji Kusano ◽  
Shigeaki Muto ◽  
Tetsu Akimoto ◽  
Satoru Yanagiba ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mesangial Cells ◽  
Nuclear Factor Κb ◽  
Inos Mrna ◽  
No Production ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Inos Protein ◽  
Nitrite Production ◽  
Inhibitor Of Protein Synthesis

The present study examined how arginine vasopressin (AVP) affects nitric oxide (NO) metabolism in cultured rat glomerular mesangial cells (GMC). GMC were incubated with test agents and nitrite, and intracellular cGMP content, inducible nitric oxide synthase (iNOS) mRNA, and iNOS protein were analyzed by the Griess method, enzyme immunoassay, and Northern and Western blotting, respectively. AVP inhibited lipopolysaccharide (LPS)- and interleukin-1β (IL-1β)-induced nitrite production in a dose- and time-dependent manner, with concomitant changes in cGMP content, iNOS mRNA, and iNOS protein. This inhibition by AVP was reversed by V1- but not by oxytocin-receptor antagonist. Inhibition by AVP was also reproduced on LPS and interferon-γ (IFN-γ). Protein kinase C (PKC) inhibitors reversed AVP inhibition, whereas PKC activator inhibited nitrite production. Although dexamethasone and pyrrolidinedithiocarbamate (PDTC), inhibitors of nuclear factor-κB, inhibited nitrite production, further inhibition by AVP was not observed. AVP did not show further inhibition of nitrite production with actinomycin D, an inhibitor of transcription, or cycloheximide, an inhibitor of protein synthesis. In conclusion, AVP inhibits LPS- and IL-1β-induced NO production through a V1 receptor. The inhibitory action of AVP involves both the activation of PKC and the transcription of iNOS mRNA in cultured rat GMC.

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.

Surfactant protein A mediates mycoplasmacidal activity of alveolar macrophages

1998 ◽  
Vol 274 (2) ◽  
pp. L270-L277 ◽  
Author(s):  
Judy M. Hickman-Davis ◽  
J. Russell Lindsey ◽  
S. Zhu ◽  
S. Matalon
Keyword(s):  
Nitric Oxide ◽  
Alveolar Macrophages ◽  
Protein A ◽  
Surfactant Protein ◽  
No Production ◽  
Nitric Oxide Synthase Inhibitor ◽  
Nitrite Production ◽  
Ifn Γ ◽  
Synthase Inhibitor ◽  
Nitrate And Nitrite

Mycoplasma pneumoniae is a leading cause of pneumonia and exacerbates other respiratory diseases in humans. We investigated the potential role of surfactant protein (SP) A in antimycoplasmal defense using alveolar macrophages (AMs) from C57BL/6NCr (C57BL) mice, which are highly resistant to infections of Mycoplasma pulmonis. C57BL AMs, activated with interferon (IFN)-γ and incubated with SP-A (25 μg/ml) at 37°C, produced significant amounts of nitric oxide (⋅ NO; nitrate and nitrite production = 1.1 μM ⋅ h−1⋅ 105AMs−1) and effected an 83% decrease in mycoplasma colony-forming units (CFUs) by 6 h postinfection. Preincubation of AMs with the inducible nitric oxide synthase inhibitor NG-monomethyl-l-arginine abolished ⋅ NO production and SP-A-mediated killing of mycoplasmas. No decrease in CFUs was seen when IFN-γ-activated macrophages were infected with mycoplasmas in the absence of SP-A despite significant ⋅ NO production (nitrate and nitrite production = 0.6 μM ⋅ h−1⋅ 105AMs−1). These results demonstrate that SP-A mediates killing of mycoplasmas by AMs, possibly through an ⋅ NO-dependent mechanism.

Cytokine and inflammatory mediators are associated with cytotoxic, anti-inflammatory and apoptotic activity of honeybee venom

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed A. Salama ◽  
Mohamed A. Younis ◽  
Roba M. Talaat
Keyword(s):  
Nitric Oxide ◽  
Cell Lines ◽  
Cancer Cell ◽  
Hela Cells ◽  
No Production ◽  
Hep G2 ◽  
Normal Cells ◽  
Tnf Α ◽  
Ifn Γ ◽  
Mcf 7

AbstractObjectiveThe present study aimed to evaluate cytotoxic, apoptotic, and anti-inflammatory properties of bee venom (BV) as well as changes in cytokine secretion levels and nitric oxide (NO) production using three different cancer cell lines [liver (Hep-G2), breast (MCF-7), and cervical (HPV-18 infected HeLa cells)] and two normal cells (splenocytes and macrophages (MQ).MethodsCytotoxic activity of BV against tumor cell lines and normal splenocytes/MQ was tested by MTT assay. By ELISA (ELISA); Tumor necrosis factor (TNF-α), Interleukine (IL-10) and interferon (IFN-γ) were measured. Caspase three expressions was evaluated using reverse transcription-polymerase chain reaction (RT-PCR). Nitric oxide (NO) was estimated using a colorimetric assay.ResultsBV has a significant cytotoxic effect on all cell lines in a dose- and time-dependent manner; none of them was toxic for normal cells. Treating Hep-G2 cells with BV showed a reduction in IL-10, elevation in TNF-α with no change in IFN-γ level. MCF-7 cells have low IL-10 and TNF-α and high IFN-γ production level. Elevation of IL-10 and IFN-γ coincides with a reduction in TNF-α level was demonstrated in HeLa cells. The expression of Caspase three was dramatically increased with elevation in BV concentration in all tested cancer cell lines. A gradual decrease in NO production by MQ with increasing BV dose was observed.ConclusionTaken together, our results stressed on the importance of BV as a potent anti-tumor agent against various types of cancers (Liver, Breast, and Cervix). Further steps towards the use of BV for pharmacological purposes must be done.

Temporal dynamics of nitric oxide wave in early vasculogenesis

2021 ◽  
pp. 1358863X2110354
Author(s):  
Saranya Rajendran ◽  
Lakshmikirupa Sundaresan ◽  
Geege Venkatachalam ◽  
Krithika Rajendran ◽  
Jyotirmaya Behera ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Temporal Dynamics ◽  
Quantitative Polymerase Chain Reaction ◽  
Hypoxia Inducible Factor ◽  
Polymerase Chain Reaction Analysis ◽  
Tube Formation ◽  
Nitrite Reduction ◽  
Inos Mrna ◽  
No Production ◽  
Area Vasculosa

Endothelium-derived nitric oxide (NO) is a mediator of angiogenesis. However, NO-mediated regulation of vasculogenesis remains largely unknown. In the present study, we show that the inhibition of NO significantly attenuated endothelial migration, ring formation, and tube formation. The contribution of nitric oxide synthase (NOS) enzymes during early vasculogenesis was assessed by evaluating endothelial NOS (eNOS) and inducible NOS (iNOS) mRNA expression during HH10–HH13 stages of chick embryo development. iNOS but not eNOS was expressed at HH12 and HH13 stages. We hypothesized that vasculogenic events are controlled by NOS-independent reduction of nitrite to NO under hypoxia during the very early phases of development. Semi-quantitative polymerase chain reaction analysis of hypoxia-inducible factor-1α (HIF-1α) showed higher expression at HH10 stage, after which a decrease was observed. This observation was in correlation with the nitrite reductase (NR) activity at HH10 stage. We observed a sodium nitrite-induced increase in NO levels at HH10, reaching a gradual decrease at HH13. The possible involvement of a HIF/NF-κB/iNOS signaling pathway in the process of early vasculogenesis is suggested by the inverse relationship observed between nitrite reduction and NOS activation between HH10 and HH13 stages. Further, we detected that NR-mediated NO production was inhibited by several NR inhibitors at the HH10 stage, whereas the inhibitors eventually became less effective at later stages. These findings suggest that the temporal dynamics of the NO source switches from NR to NOS in the extraembryonic area vasculosa, where both nitrite reduction and NOS activity are defined by hypoxia.

Cytokines activate inducible nitric oxide synthase gene transcription in inner medullary collecting duct cells

1995 ◽  
Vol 268 (4) ◽  
pp. F770-F777 ◽  
Author(s):  
M. G. Mohaupt ◽  
J. Schwobel ◽  
J. L. Elzie ◽  
G. S. Kannan ◽  
B. C. Kone
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Cytokines ◽  
Collecting Duct ◽  
Tnf Alpha ◽  
Inos Mrna ◽  
No Production ◽  
Inos Gene ◽  
Medullary Collecting Duct ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

The effects of lipopolysaccharide (LPS) and/or inflammatory cytokines on the expression of inducible nitric oxide synthase (iNOS) were studied in mIMCD-3 cells, derived from the murine inner medullary collecting duct. Under basal conditions, the production of nitrite, a stable metabolite of NO, was negligible; however, incubation with tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IF-gamma) for 24 h resulted in a 12-fold increase in nitrite synthesis and the appearance of abundant iNOS mRNA and protein. The induction of nitrite production and iNOS mRNA was time dependent, requiring approximately 8 h for expression of significant levels of nitrite or iNOS mRNA. Coincubation with the transcription inhibitor actinomycin D or the translation inhibitor cycloheximide prevented the cytokine induction of iNOS mRNA and NO production, indicating that synthesis of intermediary proteins stimulated transcription of the iNOS gene. Nuclear run-on transcription demonstrated that the iNOS gene was transcriptionally inactive under basal conditions, but was markedly induced by TNF-alpha and IF-gamma. These results indicate that inflammatory cytokines stimulate NO production in mIMCD-3 cells by activating iNOS gene transcription in a process that requires new protein synthesis.

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