scholarly journals Nitric oxide inhibits superoxide production by inflammatory polymorphonuclear leukocytes

1998 ◽  
Vol 274 (3) ◽  
pp. C827-C830 ◽  
Author(s):  
Jesús Ródenas ◽  
M. Teresa Mitjavila ◽  
Teresa Carbonell

Nitric oxide (NO ⋅) has a complex role in the inflammatory response. In this study, we modified the levels of endogenous NO ⋅ in vivo in an acute model of inflammation and evaluated the interactions between NO ⋅ and superoxide anion ([Formula: see text]) produced by polymorphonuclear leukocytes (PMNs) accumulated in the inflamed area. We injected phosphate-buffered saline (control group), 6 μmol ofl- N 5-(1-iminoethyl)ornithine (l-NIO group), or 6 μmol ofl-arginine (l-arginine group) into the granuloma pouch induced by carrageenan in rats.[Formula: see text] plus[Formula: see text] (indicative of NO ⋅ generation) was 188 nmol in the exudate of the control group, but it decreased in the l-NIO group ( P < 0.05) and increased in thel-arginine group ( P < 0.05). When PMNs from treated rats were incubated in vitro, the production of superoxide anion ([Formula: see text]) decreased by ∼46% in thel-arginine group. Furthermore,[Formula: see text] was inhibited in PMNs whenl-arginine was added to the incubation medium before phorbol 12-myristate 13-acetate stimulation but not when added simultaneously. Our results suggest a protective role for NO ⋅ in inflammation, through the inactivation of NADPH oxidase and the consequent impairment of[Formula: see text] production for cell-mediated injury.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Qian-wei Li ◽  
Qin Yang ◽  
Hong-Yang Liu ◽  
Yu-ling Wu ◽  
Yu-Hua Hao ◽  
...  

Sepsis increases the risk of the liver injury development. According to the research works, coenzyme Q10 exhibits hepatoprotective properties in vivo as well as in vitro. Current work aimed at investigating the protective impacts of coenzyme Q10 against liver injury in septic BALB/c mice. The male BALB/c mice were randomly segregated into 4 groups: the control group, the coenzyme Q10 treatment group, the puncture and cecal ligation group, and the coenzyme Q10+cecal ligation and puncture group. Cecal ligation and puncture was conducted after gavagaging the mice with coenzyme Q10 during two weeks. Following 48 h postcecal ligation and puncture, we estimated hepatic biochemical parameters and histopathological changes in hepatic tissue. We evaluated the expression of factors associated with autophagy, pyroptosis, and inflammation. Findings indicated that coenzyme Q10 decreased the plasma levels in alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase in the cecal ligation and puncture group. Coenzyme Q10 significantly inhibited the elevation of sequestosome-1, interleukin-1β, oligomerization domain-like receptor 3 and nucleotide-binding, interleukin-6, and tumor necrosis factor-α expression levels; coenzyme Q10 also increased beclin 1 levels. Coenzyme Q10 might be a significant agent in the treatment of liver injury induced by sepsis.


1996 ◽  
Vol 80 (6) ◽  
pp. 1984-1992 ◽  
Author(s):  
J. M. Graf ◽  
C. W. Smith ◽  
M. M. Mariscalco

Human neonatal polymorphonuclear leukocytes (PMNs) exhibit decreased mobility, adherence, and transendothelial migration in vitro compared with adult PMNs. These deficits, in part, are due to functional and quantitative defects in neonatal Mac-1 (CD11b/CD18), whereas LFA-1 (CD11a/CD18) function is similar to that found in adults (D.C.Anderson, O.Abbassi, T.K.Kishimoto, J.M.Koenig, L.V.McIntire, and C.W.Smith, J.Immunol. 146: 3372-3379, 1991; C. W. Smith, T. K. Kishimoto, O. Abbassi, B.J.Hughes, R.Rothlein, L.V.McIntire, E.Butcher, and D.C. Anderson, J. Clin. Invest. 87: 609-618, 1991). We tested the hypothesis that the primary mechanism for the neonatal PMN CD18-dependent emigration in vivo is due to LFA-1. Neutrophils from 1-day-old rabbit pups had 32 and 60% of adult rabbit levels of CD11a and CD11b, respectively. Rabbit pups or adult rabbits received the monoclonal antibody (MAb) R7.1 (anti-CD11a) or R15.7 (anti-CD18) or the vehicle phosphate-buffered saline (PBS) before the instillation of intraperitoneal thioglycollate. Six hours later peritoneal exudate was collected. The administration of MAbs R7.1 and R15.7 in adult animals resulted in 60 and 83% inhibition of leukocyte emigration, respectively, compared with PBS-treated animals (P < 0.01). In neonatal animals, R7.1 and R15.7 inhibited leukocyte peritoneal accumulation to the same extent (50 and 60%, respectively) compared with PBS-treated animals (P < 0.01). Adult animals were also treated with the anti-CD11b MAb 198. MAb 198 decreased emigration by 25%, although this was not significant compared with PBS-treated animals. We conclude that although neonatal animals have significantly less neutrophil CD11a, the diminished levels did not contribute to a reduced ability to emigrate to the peritoneum and, like adult animals, neonatal animals primarily utilize LFA-1 for accumulation in this model. The contribution of Mac-1 to neonatal leukocyte emigration remains uncertain.


2015 ◽  
Vol 35 (2) ◽  
pp. 516-528 ◽  
Author(s):  
Jianchun Huang ◽  
Xudong Zhang ◽  
Feizhang Qin ◽  
Yingxin Li ◽  
Xiaoqun Duan ◽  
...  

Background: Previous studies have demonstrated that Millettia pulchra flavonoids (MPF) exhibit protective effects on myocardial ischemia reperfusion injury (MI/RI) in isolated rat hearts and show anti-oxidative, anti-hypoxic and anti-stress properties. Methods: In this study, the cardioprotective effects of MPF on myocardial ischemia and its underlying mechanisms were investigated by a hypoxia/ reoxygenation (H/R) injury model in vitro and a rat MI/RI model in vivo. Results: We found that the lactate dehydrogenase (LDH) and inducible nitric oxide synthase (iNOS) activities were decreased in the MPF pretreatment group, whereas the activities of constructional nitric oxide synthase (cNOS), total nitric oxide synthase (tNOS), Na+-K+-ATPase and Ca2+-Mg2+-ATPase were significantly increased. In addition, the cardiocytes were denser in the MPF groups than in the control group. The mortality rate and apoptosis rate of cardiocytes were significantly decreased. Furthermore, pretreatment with MPF in vivo significantly improved the hemodynamics, decreased malondialdehyde (MDA) abundance, increased the activities of plasma superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreased the expression of the Bax protein and ratio Bax/Bc1-2 ration. Conclusions: These results suggest that MPF is an attractive protective substance in myocardial ischemia due to its negative effects on heart rate and ionotropy, reduction of myocardial oxidative damage and modulation of gene expression associated with apoptosis.


2015 ◽  
Vol 27 (1) ◽  
pp. 246 ◽  
Author(s):  
H. Fernandes ◽  
L. Schefer ◽  
F. C. Castro ◽  
C. L. V. Leal

Melatonin is a pineal hormone related to the control of the circadian cycle, besides the reproductive seasonality of some animal species, and has shown positive effects on oocyte maturation and embryo development. The aim of this study was to assess the effects of melatonin on in vivo and in vitro maturation of mouse oocytes. Female F1 hybrids (C57BL/6 × CBA; n = 8 per group/treatment) were used in 3 different treatments (trt) groups: (I) in vivo trt: mice received 2 different doses of melatonin injections, 10 and 20 mg kg–1 per IP including a saline control dose (0 mg kg–1 per IP) for 4 days along with ovarian stimulation trt of 5 IU of eCG IP, followed by 5 IU of hCG IP 48 h later, and cumulus-oocyte complexes (COC) were collected 16 h after hCG; (II) mice received a similar in vivo melatonin trt, but ovarian stimulation trt was only 5 IU of eCG, no hCG, and COC were collected after 48 h and subsequently matured in vitro with 0.5 µg mL–1 of FSH for 16 h; (III) in vitro maturation of oocytes: COC were collected 48 h after 5 IU of eCG and maturated in the presence of 3 different doses of melatonin (10–9, 10–6, and 10–3 M) or 0.5 µg mL–1 of FSH (control) for 16 h. In vitro-maturing oocytes were in incubated at 37°C, 5% CO2, and 95% humidity. Maturation rates were evaluated according to the presence of the first polar body under an inverted microscope. Statistical analyses were performed by ANOVA followed by Tukey's test (4 replicates). In the first treatment, 20 mg kg–1 of melatonin showed the highest in vivo maturation rate, 80.3% (61/76), while 10 mg kg–1 of melatonin was 62.4% (53/85) and the saline control group was 69.4% (77/111), but differences were not significant (P > 0.05). For in vitro maturation of oocytes from animals previously treated with melatonin, the 10 mg kg–1 of melatonin group had the highest maturation rate, 53.2% (99/186), in comparison with the saline and 20 mg kg–1 of melatonin groups, which showed 46.6 (88/189) and 39.0% (85/218), respectively; again, no differences were detected (P > 0.05). In the last treatment, the maturation rates increased from 48.9 (43/88) to 53.7 (51/95) and 56.0% (56/100) as the melatonin concentrations decreased from 10–3, 10–6, and 10–9 M, respectively. The control group had the highest rate of 57.3% (55/96), but no statistical differences were observed (P = 0.706). In conclusion, under the conditions studied, melatonin was unable to improve the maturation rate neither after in vivo nor in vitro treatment. However, during in vitro maturation, melatonin alone was as efficient as FSH in promoting maturation in murine oocytes, indicating its potential effect on stimulating meiosis. Therefore, the role of melatonin in stimulating meiosis needs further investigation.Acknowledgments to FAPESP for fellowship (HF) and funding (CLVL).


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Silvia I García ◽  
Ludmila S Peres Diaz ◽  
Maia Aisicovich ◽  
Mariano L Schuman ◽  
María S Landa

Cardiac TRH (cTRH) is overexpressed in the hypertrophied ventricle (LV) of the SHR. Additionally in vivo siRNA-TRH treatment induced downregulation of LV-TRH preventing cardiac hypertrophy and fibrosis demonstrating that TRH is involved in hypertrophic and fibrotic processes. Moreover, in a normal heart, the increase of LV TRH expression alone could induce structural changes where fibrosis and hypertrophy could be involved, independently of any other system alterations. Is well-known the cardiac hypertrophy/ fibrotic effects induced by AII, raising the question of whether specific LV cTRH inhibition might attenuates AII induced cardiac hypertrophy and fibrosis in mice. We challenged C57 mice with AII (osmotic pumps,14 days; 2 mg/kg) to induce cardiac hypertrophy vs saline. Groups were divided and , simultaneously to pump surgery, injected intracardiac with siRNA-TRH and siRNA-Con as its control. Body weight, water consume and SABP were measured daily. As expected, AII significantly increased SABP (p<0.05) in both groups treated , although cardiac hypertrophy (heart weight/body weight) was only evident in the group with the cardiac TRH system undamaged, suggesting that the cardiac TRH system function as a necessary mediator of the AII-induced hypertrophic effect. As hypothesized, we found an AII-induced increase of TRH (p<0.05) gene expression (real-t PCR) confirmed by immunofluorescence that was not observed in the group AII+siRNA-TRH demonstrating the specific siRNA treatment efficiency. Furthermore, AII significantly increase (p<0.05) BNP (hypertrophic marker), III collagen and TGFB (fibrosis markers) expressions only in the group with AII with the cardiac TRH system intact. On the contrary, the group with AII and the cTRH system inhibited, shows genes expressions similar to the saline control group. We confirmed these results by immunofluorescence. Similar fibrotic results were observed with NIH3T3 cell culture where we demonstrated that AII induced TRH gene expression (p<0.05) and its inhibition impedes AII-induced increase of TGFB and III/I collagens expressions telling us about the role of the cTRH in the AII fibrosis effects. Our results point out that the cardiac TRH is involved in the AII-induced hypertrophic and fibrotic effects.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3264-3264
Author(s):  
Enzi Jiang ◽  
Eugene Park ◽  
Cu Nguyen ◽  
James Yoon ◽  
Yao-Te Hsieh ◽  
...  

Abstract Abstract 3264 Survivin, an inhibitor of apoptosis protein (IAP) family, has been associated with poor prognosis in cancer including leukemia. Survivin can be downregulated in colon cancer cells by inhibition of the β-catenin/Creb-binding protein (CBP) interaction using ICG-001, a small molecule specific inhibitor of the β-catenin/CBP interaction. We have shown previously that combined ICG-001 and chemotherapy can downregulate Survivin and sensitize ALL cells to chemotherapy in vitro and in a pilot study in vivo. In this study, we determine the CBP interaction with ICG-001 in primary ALL cells and preclinically evaluate ICG-001 in vitro and in vivo as an adjuvant against primary ALL and. For this purpose, primary ALL cells were co-cultured with OP9 cells and treated for 4 days with ICG-001 (10mM, 20mM) or DMSO as vehicle control. Mean viability (trypan blue exclusion) of cells treated with ICG-001 was significantly lower (ICG-001 10mM: 75.12% ± 3.15%; 20mM: 41.18%± 7.88%) compared to cells treated with DMSO (84.99% ± 0.42%) (% cell viability relative to initial control) (p=0.03). Real time RT-PCR showed ICG-001 dose-dependent downregulation of Survivin in ALL compared to control (ICG10mM vs. control: p=0.0037 and 20mM vs. control: p=0.0031). Immunoblotting demonstrated reduction of Survivin after ICG-001 treatment. Primary ALL cells incubated with a combination of VDL (Vincristine, Dexamethasone and L-Asparaginase) and ICG-001 showed decreased viability (28.7%± 4.9%) versus VDL only (79.3%± 13.6%) (p=0.014) determined by MTT assay. To elucidate if ICG-001 interacts with β-catenin/CBP as shown previously in colon cancer, we analyzed ten primary pre-B ALL cells and found significantly greater γ-catenin and Survivin expression versus normal pre-B-Cells. β-catenin was absent or in some cases expressed only weakly. Expression of v-catenin and b-catenin in ALL xenograft cells were detected by Western blot. One primary ALL was selected and incubated with γ-catenin and β-catenin siRNA for 48hrs, followed by 6hrs incubation with Wnt3a. Wnt3a induced both of γ-catenin and β-catenin expression. Survivin was reduced by γ-catenin siRNA but not β-catenin siRNA treatment. Addition of Wnt3a partially recovered the decrease of Survivin. In addition, Survivin was knocked down in primary ALL using shRNA and non-silencing shRNA control or ICG-001 (2uM) and DMSO control. Western blot analysis showed that survivin shRNA or ICG-001 treatment lead to downregulation of Survivin and γ-catenin. Using a ChIP assay we could demonstrate occupancy of TCF4 and CBP association at the Survivin promoter, which was not altered by ICG-001 in primary ALL. Moreover, ICG-001 treatment of primary ALL cells prevents CBP but not p300 occupancy. For further preclinical in vivo evaluation of ICG-001, one Philadelphia chromosome positive ALLs (Ph+) and two Ph− primary ALL were injected into sublethally irradiated NOD/SCID IL2Rγ−/-mice and treated with ICG-001 (50mg or 100mg/kg/day per subcutaneous miniosmotic pump) with or without chemotherapy including VDL for Ph− ALL (per intraperitoneal injections) or Nilotinib for Ph+ ALL (per os). For analysis we pooled the survival of all three primary leukemias. The saline control group (n=10) (MST= 55.5.days) and the ICG-001 only groups (n=3) (MST=61 days) died rapidly. The group treated with chemotherapy (n=13) had a median survival time (MST) of 85 days. In marked contrast, the group treated with the combined chemotherapy+ICG-001 (n=15) lived significantly longer (MST=100) (p<0.05). Taken together, our data shows that Survivin transcription can be mediated by γ-catenin in primary ALL and that targeting CBP/γ-catenin by using ICG-001 ALL can sensitize ALL cells to chemotherapy in vitro and in vivo. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3909-3914 ◽  
Author(s):  
Stefan Barth ◽  
Michael Huhn ◽  
Bärbel Matthey ◽  
Samir Tawadros ◽  
Roland Schnell ◽  
...  

The human lymphocyte activation marker CD30 is highly overexpressed on Hodgkin/Reed–Sternberg cells and represents an ideal target for selective immunotherapy. We used the murine anti-CD30 hybridoma Ki-4 to construct a new recombinant immunotoxin (rIT) for possible clinical use in patients with CD30+ lymphoma. Hybridoma V genes were polymerase chain reaction-amplified, assembled, cloned, and expressed as a mini-library for display on filamentous phage. Functional Ki-4 scFv obtained by selection of binding phage on the CD30-expressing Hodgkin lymphoma cell line L540cy was inserted into the bacterial expression vector pBM1.1 and fused to a deletion mutant ofPseudomonas exotoxin A (ETA′). Periplasmically expressed Ki-4(scFv)–ETA′ demonstrated specific activity against a variety of CD30+ lymphoma cells as assessed by different in vitro assays. To evaluate in vivo antitumor activity, severe combined immunodeficient mice challenged with human lymphoma cell lines were treated with the immunotoxin. The blood distribution time t½ of Ki-4(scFv)–ETA′ was 19 minutes, and its serum elimination time t½ was 193 minutes. A single intravenous injection of 40 μg rIT 1 day after tumor inoculation rendered 90% of the mice tumor free, extending the mean survival time to more than 200 days compared with 38.1 days in the phosphate-buffered saline control group (P < .001). This new rIT is a promising candidate for further clinical evaluation in patients with Hodgkin lymphoma or other CD30+malignancies.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Feixiang Wu ◽  
Yantao Liu ◽  
Xin Lv ◽  
Xuerong Miao ◽  
Yuming Sun ◽  
...  

Objective. The present study was to investigate the feasibility of adenovirus-mediated small interference RNA (siRNA) targeting Toll-like receptor 4 (TLR4) gene in ameliorating lipopolysaccharide- (LPS-) induced acute lung injury (ALI).Methods.In vitro, alveolar macrophages (AMs) were treated with Ad-siTLR4 and Ad-EFGP, respectively, for 12 h, 24 h, and 48 h, and then with LPS (100 ng/mL) for 2 h, and the function and expression of TLR4 were evaluated.In vivo, rats received intratracheal injection of 300 μL of normal saline (control group), 300 μL of Ad-EGFP (Ad-EGFP group), or 300 μL of Ad-siTLR4 (Ad-siTLR4 group) and then were intravenously treated with LPS (50 mg/kg) to induce ALI.Results. Ad-siTLR4 treatment significantly reduced TLR4 expression and production of proinflammatory cytokines following LPS treatment bothin vitroandin vivo. Significant alleviation of tissue edema, microvascular protein leakage, and neutrophil infiltration was observed in the AdsiTLR4-treated animals.Conclusion. TLR4 plays a critical role in LPS-induced ALI, and transfection of Ad-siTLR4 can effectively downregulate TLR4 expressionin vitroandin vivo, accompanied by alleviation of LPS-induced lung injury. These findings suggest that TLR4 may serve as a potential target in the treatment of ALI and RNA interfering targeting TLR4 expression represents a therapeutic strategy.


1997 ◽  
Vol 185 (7) ◽  
pp. 1261-1274 ◽  
Author(s):  
Tanya M. Scharton-Kersten ◽  
George Yap ◽  
Jeanne Magram ◽  
Alan Sher

The induction by IFN-γ of reactive nitrogen intermediates has been postulated as a major mechanism of host resistance to intracellular pathogens. To formally test this hypothesis in vivo, the course of Toxoplasma gondii infection was assessed in nitric oxide synthase (iNOS)−/− mice. As expected, macrophages from these animals displayed defective microbicidal activity against the parasite in vitro. Nevertheless, in contrast to IFN-γ−/− or IL-12 p40−/− animals, iNOSdeficient mice survived acute infection and controlled parasite growth at the site of inoculation. This early resistance was ablated by neutralization of IFN-γ or IL-12 in vivo and markedly diminished by depletion of neutrophils, demonstrating the existence of previously unappreciated NO independent mechanisms operating against the parasite during early infection. By 3-4 wk post infection, however, iNOS knockout mice did succumb to T. gondii. At that stage parasite expansion and pathology were evident in the central nervous system but not the periphery suggesting that the protective role of nitric oxide against this intracellular infection is tissue specific rather than systemic.


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