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 ◽  
...  

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.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haidy A. Saleh ◽  
Eman Ramdan ◽  
Mohey M. Elmazar ◽  
Hassan M. E. Azzazy ◽  
Anwar Abdelnaser

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.


1998 ◽  
Vol 66 (4) ◽  
pp. 1309-1316 ◽  
Author(s):  
Antoine Gross ◽  
Sandra Spiesser ◽  
Annie Terraza ◽  
Bruno Rouot ◽  
Emmanuelle Caron ◽  
...  

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.


2004 ◽  
Vol 72 (1) ◽  
pp. 359-363 ◽  
Author(s):  
Laura Edith Fichera ◽  
Maria Cecilia Albareda ◽  
Susana Adriana Laucella ◽  
Miriam Postan

ABSTRACT The effect of interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) on Trypanosoma cruzi multiplication and nitric oxide (NO) production in cardiac myocytes was investigated. Cardiac myocyte cultures were obtained from neonatal Wistar rat hearts, infected with T. cruzi, and treated with IL-1β, TNF-α, IFN-γ, or N-monomethyl-l-arginine (l-NAME) for 72 h. Parasite growth was calculated from the number of infected cells in Giemsa-stained smears. Nitric oxide production was determined with the Griess reagent. Inducible nitric oxide synthase (iNOS) expression by cardiac myocytes was detected by Western blot. The results showed that the percentages of cardiac myocytes containing T. cruzi amastigotes in cytokine-treated cultures were significantly lower than in nontreated cultures. The addition of l-NAME reversed the inhibitory effect on parasite growth of IL-1β and TNF-α but not of IFN-γ. Nitrite levels released by T. cruzi-infected and noninfected cardiac myocyte cultures after 72 h of stimulation with IL-1β were significantly higher than those produced upon treatment with TNF-α, IFN-γ, or medium alone, regardless of the infection status. Nitrite levels in TNF-α-stimulated infected cultures were significantly higher than in untreated infected cultures and TNF-α-treated noninfected cultures. l-NAME inhibited IL-1β- but not TNF-α-induced NO production, indicating the presence of iNOS-dependent and iNOS-independent mechanisms for NO formation in this experimental system. iNOS expression was detected in infected and noninfected cardiac myocytes stimulated with IL-1 β and TNF-α but not with IFN-γ. These results suggest an important role for cardiac myocytes and locally secreted cytokines in the control of parasite multiplication in T. cruzi-induced myocarditis.


2002 ◽  
Vol 70 (8) ◽  
pp. 4247-4253 ◽  
Author(s):  
A. Talvani ◽  
F. S. Machado ◽  
G. C. Santana ◽  
A. Klein ◽  
L. Barcelos ◽  
...  

ABSTRACT The production of nitric oxide (NO) by gamma interferon (IFN-γ)-activated macrophages is a major effector mechanism during experimental Trypanosoma cruzi infection. In addition to IFN-γ, chemoattractant molecules, such as platelet-activating factor (PAF) and CC chemokines, may also activate macrophages to induce NO and mediate the killing of T. cruzi in an NO-dependent manner. Here we investigated the ability of leukotriene B4 (LTB4) to induce the production of NO by macrophages infected with T. cruzi in vitro and whether NO mediated LTB4-induced parasite killing. The activation of T. cruzi-infected but not naive murine peritoneal macrophages with LTB4 induced the time- and concentration-dependent production of NO. In addition, low concentrations of LTB4 acted in synergy with IFN-γ to induce NO production. The NO produced mediated LTB4-induced microbicidal activity in macrophages, as demonstrated by the inhibitory effects of an inducible NO synthase inhibitor. LTB4-induced NO production and parasite killing were LTB4 receptor dependent and were partially blocked by a PAF receptor antagonist. LTB4 also induced significant tumor necrosis factor alpha (TNF-α) production, and blockade of TNF-α suppressed LTB4-induced NO release and parasite killing. A blockade of LTB4 or PAF receptors partially inhibited IFN-γ-induced NO and TNF-α production but not parasite killing. Finally, daily treatment of infected mice with CP-105,696 was accompanied by a significantly higher level of blood parasitemia, but not lethality, than that seen in vehicle-treated animals. In conclusion, our results suggest a role for LTB4 during experimental T. cruzi infection. Chemoattractant molecules such as LTB4 not only may play a major role in leukocyte migration into sites of inflammation in vivo but also, in the event of an infection, may play a relevant role in the activation of recruited leukocytes to kill the invading microorganism in an NO-dependent manner.


2000 ◽  
Vol 68 (11) ◽  
pp. 6209-6214 ◽  
Author(s):  
Akiko Morikawa ◽  
Naoki Koide ◽  
Yutaka Kato ◽  
Tsuyoshi Sugiyama ◽  
Dipshikha Chakravortty ◽  
...  

ABSTRACT The effect of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and lipopolysaccharide (LPS) on nitric oxide (NO) production in the mouse vascular aortic endothelial cell line END-D was examined. LPS, TNF-α, and a low concentration of IFN-γ inhibited NO production in END-D cells, while a high concentration of IFN-γ definitely enhanced it. The NO production induced by a high concentration of IFN-γ was further augmented by using IFN-γ in combination with LPS or TNF-α. In sequential incubations of LPS and IFN-γ, the enhancement of NO production required prior treatment with IFN-γ. Stimulation of END-D cells with a high concentration of IFN-γ led to the expression of inducible NO synthase (iNOS). The augmentation of NO production by IFN-γ alone or in combination with LPS or TNF-α was completely blocked by several inhibitors of iNOS. It was strongly suggested that a high concentration of IFN-γ itself enhanced NO production in END-D cells through inducing the expression of iNOS. LPS and TNF-α exclusively modulated the activity of iNOS once its expression was triggered by IFN-γ. On the other hand, a low concentration of IFN-γ, LPS, and TNF-α reduced NO production through down-regulating constitutive NOS (cNOS). The differential regulation of cNOS- and iNOS-mediated NO production by IFN-γ, TNF-α, and LPS is discussed.


Author(s):  
Mohamed A. Salama ◽  
Mohamed A. Younis ◽  
Roba M. Talaat

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.


2003 ◽  
Vol 1 (3) ◽  
pp. 113-117 ◽  
Author(s):  
M. Myronidou ◽  
B. Kokkas ◽  
A. Kouyoumtzis ◽  
N. Gregoriadis ◽  
A. Lourbopoulos ◽  
...  

In these studies we investigated if losartan, an AT1- receptor blocker has any beneficial effect on NO production from the bovine aortic preparations in vitro while under stimulation from angiotensin II. Experiments were performed on intact specimens of bovine thoracic aorta, incubated in Dulbeco's MOD medium in a metabolic shaker for 24 hours under 95 % O2 and 5 % CO2 at a temperature of 37°C. We found that angiotensin II 1nM−10 μM does not exert any statistically significant action on NO production. On the contrary, angiotensin II 10nM increases the production of NO by 58.14 % (from 12.16 + 2.9 μm/l to 19.23 + 4.2 μm/l in the presence of losartan 1nM (P<0.05). Nitric oxide levels depend on both rate production and rate catabolism or chemical inactivation. Such an equilibrium is vital for the normal function of many systems including the cardiovascular one. The above results demonstrate that the blockade of AT1-receptors favors the biosynthesis of NO and indicate the protective role of losartan on the vascular wall.


2020 ◽  
Vol 472 (10) ◽  
pp. 1469-1480
Author(s):  
Bashair M. Mussa ◽  
Ankita Srivastava ◽  
Abdul Khader Mohammed ◽  
Anthony J. M. Verberne

Abstract Dysfunction of the pancreatic β cells leads to several chronic disorders including diabetes mellitus. Several mediators and mechanisms are known to be involved in the regulation of β cell secretory function. In this study, we propose that cytokine-induced nitric oxide (NO) production interacts with cholinergic mechanisms to modulate insulin secretion from pancreatic β cells. Using a rat insulinoma cell line INS-1, we demonstrated that β cell viability decreases significantly in the presence of SNAP (NO donor) in a concentration- and time-dependent manner. Cell viability was also found to be decreased in the presence of a combined treatment of SNAP with SMN (muscarinic receptor antagonist). We then investigated the impact of these findings on insulin secretion and found a significant reduction in glucose uptake by INS-1 cells in the presence of SNAP and SMN as compared with control. Nitric oxide synthase 3 gene expression was found to be significantly reduced in response to combined treatment with SNAP and SMN suggesting an interaction between the cholinergic and nitrergic systems. The analysis of gene and protein expression further pin-pointed the involvement of M3 muscarinic receptors in the cholinergic pathway. Upon treatment with cytokines, reduced cell viability was observed in the presence of TNF-α and IFN-γ. A significant reduction in insulin secretion was also noted after treatment with TNF-α and IFN-γ and IL1-β. The findings of the present study have shown for the first time that the inhibition of the excitatory effects of cholinergic pathways on glucose-induced insulin secretion may cause β cell injury and dysfunction of insulin secretion in response to cytokine-induced NO production.


2013 ◽  
Vol 8 (9) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Kanidta Kaewkroek ◽  
Chatchai Wattanapiromsakul ◽  
Palangpon Kongsaeree ◽  
Supinya Tewtrakul

The ethanol extract of the rhizomes of Kaempferia marginata showed a potent inhibitory effect against lipopolysaccharide (LPS)-induced nitric oxide (NO) and tumor necrosis factor-alpha (TNF-α) release in RAW264.7 cells. Moreover, the partition with various organic solvents also inhibited NO production. One new pimarane-type diterpene, 1α-acetoxysandaracopimaradien-2α-ol (5), along with four known diterpenes (1–4), were isolated from the n-hexane and chloroform layers, respectively. Among these metabolites, compounds 1 and 4 were isolated for the first time from K. marginata. Compounds 1–5 showed significant inhibitory effects on NO production, with IC50 values ranging from 38.6 to 51.9 μM. Furthermore, compound 2 also exhibited significant activity against TNF-α release (IC50 = 48.3 μM). These findings may support the use of K. marginata by traditional doctors for treatment of inflammatory-related diseases.


Gut ◽  
1999 ◽  
Vol 44 (5) ◽  
pp. 659-665 ◽  
Author(s):  
A M Chavez ◽  
M J Morin ◽  
N Unno ◽  
M P Fink ◽  
R A Hodin

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.


Sign in / Sign up

Export Citation Format

Share Document