scholarly journals Ablation of IL-17A leads to severe colitis in IL-10-deficient mice: implications of myeloid-derived suppressor cells and NO production

2019 ◽  
Vol 32 (3) ◽  
pp. 187-201
Author(s):  
Masashi Tachibana ◽  
Nobumasa Watanabe ◽  
Yuzo Koda ◽  
Yukako Oya ◽  
Osamu Kaminuma ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Diseases ◽  
Genetic Defect ◽  
Suppressor Cells ◽  
T Cell Response ◽  
No Production ◽  
Dependent Manner ◽  
Myeloid Derived Suppressor Cells ◽  
Severe Colitis

Abstract IL-10 is an immune regulatory cytokine and its genetic defect leads to gastrointestinal inflammation in humans and mice. Moreover, the IL-23/Th17 axis is known to be involved in these inflammatory disorders. IL-17A, a representative cytokine produced by Th17 cells, has an important role for the pathological process of inflammatory diseases. However, the precise function of IL-17A in inflammatory bowel disease (IBD) remains controversial. In this study, we evaluated the effect of IL-17A on colitis in IL-10-deficient (Il10−/−) mice. Mice lacking both IL-10 and IL-17A (Il10−/−Il17a−/−) suffered from fatal wasting and manifested more severe colitis compared with Il10−/−Il17a+/− mice. Moreover, we found that CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) accumulated in the bone marrow, spleen and peripheral blood of Il10−/−Il17a−/− mice. These MDSCs highly expressed inducible nitric oxide synthase (iNOS) (Nos2) and suppressed the T-cell response in vitro in a NOS-dependent manner. In correlation with these effects, the concentration of nitric oxide was elevated in the serum of Il10−/−Il17a−/− mice. Surprisingly, the severe colitis observed in Il10−/−Il17a−/− mice was ameliorated in Il10−/−Il17a−/−Nos2−/− mice. Our findings suggest that IL-17A plays suppressive roles against spontaneous colitis in Il10−/− mice in an iNOS-dependent manner and inhibits MDSC differentiation and/or proliferation.

scholarly journals ANTI-INFLAMMATORY ACTIVITY OF TINOCRISPOSIDE BY INHIBITING NITRIC OXIDE PRODUCTION IN LIPOPOLYSACCHARIDES-STIMULATED RAW 264.7 CELLS

2018 ◽  
Vol 11 (4) ◽  
pp. 149 ◽  
Author(s):  
Adek Zamrud Adnan ◽  
Muhammad Taher ◽  
Tika Afriani ◽  
Annisa Fauzana ◽  
Dewi Imelda Roesma ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Diseases ◽  
Positive Control ◽  
Inflammatory Activity ◽  
Raw 264.7 Cells ◽  
No Production ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Anti Inflammatory

 Objective: The aim of this study was to investigate in vitro anti-inflammatory activity of tinocrisposide using lipopolysaccharides (LPS)-stimulated RAW 264.7 macrophage cells. Tinocrisposide is a furano diterpene glycoside that was isolated in our previous study from Tinospora crispa.Methods: Anti-inflammatory effect was quantified spectrometrically using Griess method by measuring nitric oxide (NO) production after the addition of Griess reagent.Results: The sample concentrations of 1, 5, 25, 50, and 100 μM and 100 μM of dexamethasone (positive control) have been tested against the LPS-stimulated RAW 264.7 cells, and the results showed NO level production of 39.23, 34.00, 28.9, 20.25, 16.3, and 13.68 μM, respectively, and the inhibition level of 22.67, 33.00, 43.03, 60.10, 68.00, and 73%, respectively.Conclusions: From the study, it could be concluded that tinocrisposide was able to inhibit the formation of NO in the LPS-stimulated RAW 264.7 cells in concentration activity-dependent manner, with half-maximal inhibition concentration 46.92 μM. It can be developed as anti-inflammatory candidate drug because NO is a reactive nitrogen species which is produced by NO synthase. The production of NO has been established as a mediator in inflammatory diseases.

scholarly journals Induction and stability of human Th17 cells require endogenous NOS2 and cGMP-dependent NO signaling

2013 ◽  
Vol 210 (7) ◽  
pp. 1433-1445 ◽  
Author(s):  
Nataša Obermajer ◽  
Jeffrey L. Wong ◽  
Robert P. Edwards ◽  
Kong Chen ◽  
Melanie Scott ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
T Cells ◽  
Cd4 T Cells ◽  
Th17 Cells ◽  
De Novo ◽  
Inflammatory Diseases ◽  
Suppressor Cells ◽  
Guanosine Monophosphate ◽  
No Production ◽  
No Signaling

Nitric oxide (NO) is a ubiquitous mediator of inflammation and immunity, involved in the pathogenesis and control of infectious diseases, autoimmunity, and cancer. We observed that the expression of nitric oxide synthase-2 (NOS2/iNOS) positively correlates with Th17 responses in patients with ovarian cancer (OvCa). Although high concentrations of exogenous NO indiscriminately suppress the proliferation and differentiation of Th1, Th2, and Th17 cells, the physiological NO concentrations produced by patients’ myeloid-derived suppressor cells (MDSCs) support the development of RORγt(Rorc)+IL-23R+IL-17+ Th17 cells. Moreover, the development of Th17 cells from naive-, memory-, or tumor-infiltrating CD4+ T cells, driven by IL-1β/IL-6/IL-23/NO-producing MDSCs or by recombinant cytokines (IL-1β/IL-6/IL-23), is associated with the induction of endogenous NOS2 and NO production, and critically depends on NOS2 activity and the canonical cyclic guanosine monophosphate (cGMP)–cGMP-dependent protein kinase (cGK) pathway of NO signaling within CD4+ T cells. Inhibition of NOS2 or cGMP–cGK signaling abolishes the de novo induction of Th17 cells and selectively suppresses IL-17 production by established Th17 cells isolated from OvCa patients. Our data indicate that, apart from its previously recognized role as an effector mediator of Th17-associated inflammation, NO is also critically required for the induction and stability of human Th17 responses, providing new targets to manipulate Th17 responses in cancer, autoimmunity, and inflammatory diseases.

Determination of the enhancing action of HSP90 on neuronal nitric oxide synthase by EPR spectroscopy

2001 ◽  
Vol 281 (6) ◽  
pp. C1819-C1824 ◽  
Author(s):  
Yao Song ◽  
Jay L. Zweier ◽  
Yong Xia
Keyword(s):  
Nitric Oxide ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Heat Shock Protein 90 ◽  
Tryptophan Fluorescence ◽  
Hsp90 Inhibitor ◽  
Resonance Spectroscopy ◽  
No Production ◽  
Dependent Manner ◽  
Intact Cells

Recent studies showed that heat shock protein 90 (HSP90) enhances nitric oxide (NO) synthesis from endothelial and neuronal NO synthase (eNOS and nNOS, respectively). However, these findings were based on indirect NO measurements. Moreover, although our previous studies showed that the action of HSP90 involves increased Ca2+/calmodulin (Ca2+/CaM) binding, quantitative measurements of the effect of HSP90 on CaM binding to nNOS have been lacking. With electron paramagnetic resonance spectroscopy, we directly measured NO signals from purified nNOS. HSP90 augmented NO formation from nNOS in a dose-dependent manner. Tryptophan fluorescence-quenching measurements revealed that HSP90 markedly reduced the K d of CaM to nNOS (0.5 ± 0.1 nM vs. 9.4 ± 1.8 nM in the presence and absence of HSP90, P < 0.01). Ca2+ ionophore triggered strong NO production from nNOS-transfected cells, and this was significantly reduced by the HSP90 inhibitor geldanamycin. Thus these studies provide direct evidence demonstrating that HSP90 enhances nNOS catalytic function in vitro and in intact cells. The effect of HSP90 is mediated by the enhancement of CaM binding to nNOS.

Activation of Nitric Oxide Release and Oxidative Metabolism by Leukotrienes B4, C4, and D4 in Human Polymorphonuclear Leukocytes

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1399-1405 ◽  
Author(s):  
Gerd Lärfars ◽  
Frédérique Lantoine ◽  
Marie-Aude Devynck ◽  
Jan Palmblad ◽  
Hans Gyllenhammar
Keyword(s):  
Nitric Oxide ◽  
Rank Order ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Kinetic Properties ◽  
No Production ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cysteinyl Leukotrienes ◽  
Mediators Of Inflammation

Abstract Because arachidonate metabolites are potent mediators of inflammation, we have studied the effects of leukotriene B4(LTB4) and the cysteinyl leukotrienes C4 and D4 (LTC4 and LTD4) on the release of nitric oxide (NO), in vitro, by human polymorphonuclear granulocytes (PMN). Two independent and highly sensitive real-time methods were used for these studies, ie, the NO-dependent oxidation of oxyhemoglobin (HbO2) to methemoglobin and a NO-sensitive microelectrode. When activated with LTB4, LTC4, or LTD4, but not with other lipoxygenase products such as 5S-HETE, 5-oxo-ETE or 5S,12S-diHETE, PMN produced NO in a stimulus- and concentration-dependent manner. The rank order of potency was LTB4 = LTC4 &gt; LTD4, corresponding to 232 ± 50 pmol of NO/106 PMN for 100 nmol/L LTB4 after 30 minutes. The kinetic properties of the responses were similar for all three leukotrienes with a maximum response at 13 ± 3 minutes. Cysteinyl leukotriene and LTB4 antagonists inhibited the agonist-induced NO production by 70%, and treatment with Bordetella pertussis toxin, or chelation of cytosolic Ca2+, [Ca2+]i, also efficiently inhibited this response. In contrast, treatment of PMN with cytochalasin B (5 μg/mL) enhanced the LTB4-induced NO formation by 86%. Thus, this is the first demonstration that the cysteinyl leukotrienes LTC4 and LTD4, as well as LTB4, activate NO release from human PMN by surface receptor, G-protein and [Ca2+]i-dependent mechanisms. This effect differs from activation of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, for which only LTB4is an activator.

scholarly journals Calcium/Calmodulin Dependent Protein Kinase Kinase 2 Regulates the Expansion of Tumor-Induced Myeloid-Derived Suppressor Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei Huang ◽  
Yaping Liu ◽  
Anthony Luz ◽  
Mark Berrong ◽  
Joel N. Meyer ◽  
...  
Keyword(s):  
Immune Response ◽  
Protein Kinase ◽  
Bone Marrow Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
T Cell Response ◽  
Tumor Rejection ◽  
Myeloid Derived Suppressor Cells ◽  
Calcium Calmodulin Dependent

Myeloid-derived suppressor cells (MDSCs) are a hetero geneous group of cells, which can suppress the immune response, promote tumor progression and impair the efficacy of immunotherapies. Consequently, the pharmacological targeting of MDSC is emerging as a new immunotherapeutic strategy to stimulate the natural anti-tumor immune response and potentiate the efficacy of immunotherapies. Herein, we leveraged genetically modified models and a small molecule inhibitor to validate Calcium-Calmodulin Kinase Kinase 2 (CaMKK2) as a druggable target to control MDSC accumulation in tumor-bearing mice. The results indicated that deletion of CaMKK2 in the host attenuated the growth of engrafted tumor cells, and this phenomenon was associated with increased antitumor T cell response and decreased accumulation of MDSC. The adoptive transfer of MDSC was sufficient to restore the ability of the tumor to grow in Camkk2-/- mice, confirming the key role of MDSC in the mechanism of tumor rejection. In vitro studies indicated that blocking of CaMKK2 is sufficient to impair the yield of MDSC. Surprisingly, MDSC generated from Camkk2-/- bone marrow cells also showed a higher ability to terminally differentiate toward more immunogenic cell types (e.g inflammatory macrophages and dendritic cells) compared to wild type (WT). Higher intracellular levels of reactive oxygen species (ROS) accumulated in Camkk2-/- MDSC, increasing their susceptibility to apoptosis and promoting their terminal differentiation toward more mature myeloid cells. Mechanistic studies indicated that AMP-activated protein kinase (AMPK), which is a known CaMKK2 proximal target controlling the oxidative stress response, fine-tunes ROS accumulation in MDSC. Accordingly, failure to activate the CaMKK2-AMPK axis can account for the elevated ROS levels in Camkk2-/- MDSC. These results highlight CaMKK2 as an important regulator of the MDSC lifecycle, identifying this kinase as a new druggable target to restrain MDSC expansion and enhance the efficacy of anti-tumor immunotherapy.

scholarly journals Epithelial Invasion by Escherichia coli Bearing Dr Fimbriae Is Controlled by Nitric Oxide-Regulated Expression of CD55

2004 ◽  
Vol 72 (5) ◽  
pp. 2907-2914 ◽  
Author(s):  
Li Fang ◽  
Bogdan J. Nowicki ◽  
Petri Urvil ◽  
Pawel Goluszko ◽  
Stella Nowicki ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Escherichia Coli ◽  
Epithelial Cell Line ◽  
No Production ◽  
Dependent Manner ◽  
E Coli ◽  
Regulated Expression ◽  
Ishikawa Cells ◽  
Epithelial Invasion

ABSTRACT We previously reported that inhibition of nitric oxide (NO) increases the rate of bacteremia and maternal mortality in pregnant rats with uterine infection by Escherichia coli expressing the Dr fimbria (Dr+). Epithelial binding and invasion by Dr+ E. coli has also been shown to be dependent upon the expression level of the cellular receptor decay-accelerating factor (DAF; CD55). Here, we hypothesize that NO-related severity of infection could be mediated by changes in DAF expression and in the rate of epithelial invasion. The cellular basis of NO effects on epithelial invasion with Dr+ E. coli was studied using Ishikawa endometrial carcinoma cells as an in vitro model of the human endometrial epithelium. Initially, we show that Ishikawa cells produce NO and express both NO synthase enzymes, NOS II and NOS III, and DAF protein. We next tested the abilities of both Dr+ E. coli and a Dr− E. coli mutant to invade Ishikawa cells, and invasion was seen only with Dr+ E. coli. Invasion by Dr+ E. coli was decreased by elevated NO production and increased by NO inhibition. Elevated NO production significantly decreased DAF protein and mRNA expression in Ishikawa cells in a time- and dose-dependent manner. Here, we propose that in vitro invasion of an epithelial cell line is directly related to NO-regulated expression of DAF. The significance of NO-regulated receptor-ligand invasion is that it may represent a novel unrecognized phenomenon of epithelial defense against infection.

scholarly journals Monoterpenoids from the Fruits of Amomum tsao-ko Have Inhibitory Effects on Nitric Oxide Production

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 257
Author(s):  
Seong Su Hong ◽  
Ji Eun Lee ◽  
Yeon Woo Jung ◽  
Ju-Hyoung Park ◽  
Jung A. Lee ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Diseases ◽  
Interleukin 1 ◽  
Resonance Spectroscopy ◽  
No Production ◽  
Dependent Manner ◽  
Interleukin 1 Beta ◽  
Inhibitory Effects ◽  
Concentration Dependent Manner ◽  
First Time

In our search for novel plant-derived inhibitors of nitric oxide (NO) with potential for treating inflammatory diseases, the phytochemicals of Amomum tsao-ko fruits were investigated, leading to the isolation of one bicyclic nonane (1), three menthene skeleton monoterpenoids (2–4), and two acyclic monoterpenoids (5 and 6). Their structures were identified using one- and two-dimensional nuclear magnetic resonance spectroscopy, and mass spectrometry. To the best of our knowledge, compounds 2–5 were obtained from the genus Amomum for the first time. All isolates were tested for their ability to inhibit lipopolysaccharide-stimulated NO overproduction in RAW264.7 cells. Compound 4 was found to inhibit NO production. Western blotting analysis indicated that active compound 4 can regulate inducible NO synthase expression. In addition, lipopolysaccharide-induced interleukin 1 beta and interleukin-6 overproduction was reduced in a concentration-dependent manner.

scholarly journals Calcium/Calmodulin Dependent Protein Kinase Kinase 2 Regulates the Expansion of Tumor-induced Myeloid-Derived Suppressor Cells

2021 ◽  
Author(s):  
Wei Huang ◽  
Yaping Liu ◽  
Anthony Luz ◽  
Mark Berrong ◽  
Joel Meyer ◽  
...  
Keyword(s):  
Immune Response ◽  
Protein Kinase ◽  
Bone Marrow Cells ◽  
Suppressor Cells ◽  
Cell Types ◽  
T Cell Response ◽  
Tumor Rejection ◽  
Myeloid Derived Suppressor Cells ◽  
Calcium Calmodulin Dependent

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of cells, which can suppress the immune response, promote tumor progression and impair the efficacy of immunotherapies. Consequently, the pharmacological targeting of MDSC is emerging as a new immunotherapeutic strategy to stimulate the natural anti-tumor immune response and potentiate the efficacy of immunotherapies. Herein, we leveraged genetically modified models and a small molecule inhibitor to validate Calcium-Calmodulin Kinase Kinase 2 (CaMKK2) as a druggable target to control MDSC accumulation in tumor-bearing mice. The results indicated that deletion of CaMKK2 in the host attenuated the growth of engrafted tumor cells, and this phenomenon was associated with increased antitumor T cell response and decreased accumulation of MDSC. The adoptive transfer of MDSC was sufficient to restore the ability of the tumor to grow in Camkk2-/- mice, confirming the key role of MDSC in the mechanism of tumor rejection. In vitro studies indicated that blocking of CaMKK2 is sufficient to impair the yield of MDSC. Surprisingly, MDSC generated from Camkk2-/- bone marrow cells also showed a higher ability to terminally differentiate toward more immunogenic cell types (e.g inflammatory macrophages and dendritic cells) compared to wild type (WT). Higher intracellular levels of reactive oxygen species (ROS) accumulated in Camkk2-/- MDSC, increasing their susceptibility to apoptosis and promoting their terminal differentiation toward more mature myeloid cells. Mechanistic studies indicated that AMP-activated protein kinase (AMPK), which is a known CaMKK2 proximal target controlling the oxidative stress response, fine-tunes ROS accumulation in MDSC. Accordingly, failure to activate the CaMKK2-AMPK axis can account for the elevated ROS levels in Camkk2-/- MDSC. These results highlight CaMKK2 as an important regulator of the MDSC lifecycle, identifying this kinase as a new druggable target to restrain MDSC expansion and enhance the efficacy of anti-tumor immunotherapy.

Nitric oxide induces apoptosis in renal tubular epithelial cells through activation of caspase-8

2006 ◽  
Vol 290 (5) ◽  
pp. F1044-F1054 ◽  
Author(s):  
Caigan Du ◽  
Qiunong Guan ◽  
Hong Diao ◽  
Ziqin Yin ◽  
Anthony M. Jevnikar
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cells ◽  
Proinflammatory Cytokines ◽  
Mononuclear Cells ◽  
Caspase 8 ◽  
No Production ◽  
Dependent Manner ◽  
Tubular Epithelial Cells ◽  
Inhibitory Protein

The susceptibility or resistance of tubular epithelial cells (TEC) to apoptosis is pivotal to the long-term maintenance of kidney function following episodes of inflammation, such as graft rejection. TEC apoptosis can occur with ischemia as well as with proinflammatory cytokines and nitric oxide (NO), produced by infiltrating mononuclear cells. TEC can also produce abundant amounts of NO during inflammation but the role and regulation of NO-induced injury of TEC are not well understood. Apoptosis in TEC in vitro was determined by FACS analysis with annexin-V and propidium iodide staining. NO in culture supernatants was measured by Greiss reagent, and protein expression of inducible NO synthetase (NOS2/iNOS) and caspase-8 was examined by Western blot analysis. Here, we showed that murine TEC produced abundant amounts of NO in response to proinflammatory cytokines (IFN-γ/TNF-α) through upregulation of NOS2, and inhibition of endogenous NO production by l-NMMA reduced TEC apoptosis in cytokine-stimulated cultures. Addition of exogenous NO (sodium nitroprusside) induced TEC apoptosis as well as caspase-8 activation in a dose-dependent manner. The key role of caspase-8 in NO-induced TEC apoptosis was demonstrated by that NO-induced TEC apoptosis can be blocked by caspase-8 inhibition using z-IETD-fmk, caspase-8 silencing with shRNA or by overexpressing the endogenous caspase-8 inhibitor c-FLIP (cellular Flice-inhibitory protein). In conclusion, endogenous NO from NOS2 activity as well as exogenous NO can contribute to renal injury through apoptosis of TEC. Activation of caspase-8 plays a central role in NO-induced apoptosis and caspase-8 inhibition may be an important therapeutic target during renal inflammation.

scholarly journals Inhibitory Effects of Nitric Oxide and Gamma Interferon on In Vitro and In Vivo Replication of Marek's Disease Virus

2000 ◽  
Vol 74 (8) ◽  
pp. 3605-3612 ◽  
Author(s):  
Zheng Xing ◽  
Karel A. Schat
Keyword(s):  
Nitric Oxide ◽  
Chicken Embryo Fibroblast ◽  
Gamma Interferon ◽  
Marek's Disease ◽  
No Production ◽  
Dependent Manner ◽  
Marek’S Disease ◽  
Dose Dependent

ABSTRACT The replication of Marek's disease herpesvirus (MDV) and herpesvirus of turkeys (HVT) in chicken embryo fibroblast (CEF) cultures was inhibited by the addition ofS-nitroso-N-acetylpenicillamine, a nitric oxide (NO)-generating compound, in a dose-dependent manner. Treatment of CEF culture, prepared from 11-day-old embryos, with recombinant chicken gamma interferon (rChIFN-γ) and lipopolysaccharide (LPS) resulted in production of NO which was suppressed by the addition ofN G-monomethyl l-arginine (NMMA), an inhibitor of inducible NO synthase (iNOS). Incubation of CEF cultures for 72 h prior to treatment with rChIFN-γ plus LPS was required for optimal NO production. Significant differences in NO production were observed in CEF derived from MDV-resistant N2a (major histocompatibility complex [MHC],B 21 B 21) and MDV-susceptible S13 (MHC,B 13 B 13) and P2a (MHC,B 19 B 19) chickens. N2a-derived CEF produced NO earlier and at higher levels than CEF from the other two lines. The lowest production of NO was detected in P2a-derived CEF. NO production in chicken splenocyte cultures followed a similar pattern, with the highest levels of NO produced in cultures from N2a chickens and the lowest levels produced in cultures from P2a chickens. Replication of MDV and HVT was significantly inhibited in CEF cultures treated with rChIFN-γ plus LPS and producing NO. The addition of NMMA to CEF treated with rChIFN-γ plus LPS reduced the inhibition. MDV infection of chickens treated withS-methylisothiourea, an inhibitor of iNOS, resulted in increased virus load compared to nontreated chickens. These results suggest that NO may play an important role in control of MDV replication in vivo.

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