Carbon monoxide protects against the development of experimental necrotizing enterocolitis

2005 ◽  
Vol 289 (3) ◽  
pp. G607-G613 ◽  
Author(s):  
Brian S. Zuckerbraun ◽  
Leo E. Otterbein ◽  
Patricia Boyle ◽  
Ronald Jaffe ◽  
Jeffrey Upperman ◽  
...  

Necrotizing enterocolitis (NEC) is a disease of neonates that is increasing in incidence and often results in significant morbidity and mortality. Carbon monoxide (CO), a byproduct of the catabolism of heme, is known to have anti-inflammatory and antiapoptotic properties. In this study, we aimed to demonstrate that inhaled CO protects against the development of intestinal inflammation in a model of experimental NEC as well as decreases enterocyte cell death in vitro. Additionally, we also aimed to demonstrate that CO decreases enterocyte production of inducible nitric oxide synthase (iNOS) and nitric oxide (NO). Neonatal rats were exposed to intermittent hypoxia exposure and formula feeding to induce experimental NEC. Animals randomized to CO treatment were put in an environment containing 0.025% CO for 1 h/day on days 1–3 of life. All animals were killed on day 4 of life. In vitro experiments were performed with IEC-6 cells, a rat enterocyte cell line. Cells were examined for viability, iNOS production, and elaboration of NO. We found that CO diminished levels of serum inflammatory cytokines and nitrites, protected against intestinal inflammation, and decreased ileal iNOS production and protein nitration in a model of experimental NEC. In vitro, CO decreased cytokine- or hypoxia/endotoxin-induced iNOS and NO production. CO also abrogated TNF-α- and actinomycin D-induced apoptosis or hypoxia/endotoxin-induced cell death. In conclusion, 1 h of daily low-dose inhaled CO protected against the development of intestinal inflammation in a model of experimental NEC. iNOS and NO production were decreased by CO both in vivo and in vitro. CO may prove to be a useful clinical adjunct in the treatment of NEC.

2003 ◽  
Vol 198 (11) ◽  
pp. 1707-1716 ◽  
Author(s):  
Brian S. Zuckerbraun ◽  
Timothy R. Billiar ◽  
Sherrie L. Otterbein ◽  
Peter K.M. Kim ◽  
Fang Liu ◽  
...  

Carbon monoxide (CO) and nitric oxide (NO) each have mechanistically unique roles in various inflammatory disorders. Although it is known that CO can induce production of NO and that NO can induce expression of the cytoprotective enzyme heme oxygenase 1 (HO-1), there is no information whether the protective effect of CO ever requires NO production or whether either gas must induce expression of HO-1 to exert its functional effects. Using in vitro and in vivo models of tumor necrosis factor α–induced hepatocyte cell death in mice, we find that activation of nuclear factor κB and increased expression of inducible NO are required for the protective effects of CO, whereas the protective effects of NO require up-regulation of HO-1 expression. When protection from cell death is initiated by CO, NO production and HO-1 activity are each required for the protective effect showing for the first time an essential synergy between these two molecules in tandem providing potent cytoprotection.


2018 ◽  
Vol 18 (6) ◽  
pp. 903-913 ◽  
Author(s):  
Yanan Niu ◽  
Renyikun Yuan ◽  
Hongwei Gao ◽  
Jin-Jian Lu ◽  
Qi Kong ◽  
...  

Background:There are inconsistent reports about the role of Nitric Oxide (NO) in cancer progression and prevention. Quinones demonstrate significant anti-cancer activities both in vitro and in vivo. Objective: We investigated the effect of 2-methoxy-6-acetyl-7-methyljuglone (MAM), a natural naphthoquinone isolated from Polygonum cuspidatum Sieb. et Zucc, on NO generation and its role in DNA damage in cancer cells. Methods: BEL-7402 and A549 cells were cultured and treated with MAM. The NO generation, DNA damage, and protein expression were determined. Results: MAM induced inducible nitric oxide synthase (iNOS)/NO-mediated DNA damage response through activation of MAPKs pathways. MAM induced DNA damage by activating ATM/Chk2. MAM increased iNOS expression, NO production, and MAPKs (JNK1/2, ERK1/2, and p38MAPK) phosphorylation in concentrationand time- dependent manners. Furthermore, iNOS inhibitor 1400W, iNOS siRNA, and NO scavenger hemoglobin (Hb) could significantly reverse MAM-induced DNA damage, ATM/Chk2 activation, NO production, and cell death. In addition, MAPKs inhibitors (SP600125, U0126, and SB203580) reversed MAM-induced cell death and ATM/Chk2 activation. MAM-induced cell death was partially reversed by 1400W and Hb but enhanced by L-arginine. Conclusion: These results suggested that MAM induced iNOS/NO activation and generation mediated by MAPKs pathways, which resulted in DNA damage.


2018 ◽  
Vol 60 (No. 8) ◽  
pp. 359-366
Author(s):  
J. Li ◽  
B. Shi ◽  
S. Yan ◽  
L. Jin ◽  
Y. Guo ◽  
...  

The effects of chitosan on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) activity and gene expression in vivo or vitro were investigated in weaned piglets. In vivo, 180 weaned piglets were assigned to five dietary treatments with six replicates. The piglets were fed on a basal diet supplemented with 0 (control), 100, 500, 1000, and 2000 mg chitosan/kg feed, respectively. In vitro, the peripheral blood mononuclear cells (PBMCs) from a weaned piglet were cultured respectively with 0 (control), 40, 80, 160, and 320 µg chitosan/ml medium. Results showed that serum NO concentrations on days 14 and 28 and iNOS activity on day 28 were quadratically improved with increasing chitosan dose (P < 0.05). The iNOS mRNA expressions were linearly or quadratically enhanced in the duodenum on day 28, and were improved quadratically in the jejunum on days 14 and 28 and in the ileum on day 28 (P < 0.01). In vitro, the NO concentrations, iNOS activity, and mRNA expression in unstimulated PBMCs were quadratically enhanced by chitosan, but the improvement of NO concentrations and iNOS activity by chitosan were markedly inhibited by N-(3-[aminomethyl] benzyl) acetamidine (1400w) (P < 0.05). Moreover, the increase of NO concentrations, iNOS activity, and mRNA expression in PBMCs induced by lipopolysaccharide (LPS) were suppressed significantly by chitosan (P < 0.05). The results indicated that the NO concentrations, iNOS activity, and mRNA expression in piglets were increased by feeding chitosan in a dose-dependent manner. In addition, chitosan improved the NO production in unstimulated PBMCs but inhibited its production in LPS-induced cells, which exerted bidirectional regulatory effects on the NO production via modulated iNOS activity and mRNA expression.


2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Razika Zeghir-Bouteldja ◽  
Manel Amri ◽  
Saliha Aitaissa ◽  
Samia Bouaziz ◽  
Dalila Mezioug ◽  
...  

Hydatidosis is characterized by the long-term coexistence of larvaEchinococcus granulosusand its host without effective rejection. Previous studies demonstrated nitric oxide (NO) production (in vivo and in vitro) during hydatidosis. In this study, we investigated the direct in vitro effects of NO species: nitrite (NO2−), nitrate (NO3−) and peroxynitrite (ONOO−) on protoscolices (PSCs) viability and hydatid cyst layers integrity for 24 hours and 48 hours. Our results showed protoscolicidal activity ofNO2−andONOO−24 hours and 3 hours after treatment with 320 μM and 80 μM respectively. Degenerative effects were observed on germinal and laminated layers. The comparison of the in vitro effects of NO species on the PSCs viability indicated thatONOO−is more cytotoxic thanNO2−. In contrast,NO3−has no effect. These results suggest possible involvement ofNO2−andONOO−in antihydatic action and point the efficacy of these metabolites as scolicidal agents.


2018 ◽  
Author(s):  
Hongying Fan ◽  
Ruqin Lin ◽  
Zhenhui Chen ◽  
Xingyu Leng ◽  
Xianbo Wu ◽  
...  

AbstractCronobacter sakazakii (CS), an important pathogen, is associated with the development of necrotizing enterocolitis (NEC), infant sepsis, and meningitis. Several randomized prospective clinical trials demonstrated that oral probiotics could decrease the incidence of NEC. Previously, we isolated and characterized a novel probiotic, B. fragilis strain ZY-312. However, it remains unclear how ZY-312 protects the host from the effects of CS infection. To understand the underlying mechanisms triggering the probiotic effects, we tested the hypothesis that there was a cross-talk between probiotics/probiotics-modulated microbiota and the local immune system, governed by the permeability of the intestinal mucosa using in vitro and in vivo models for the intestinal permeability. The probiotic effects of ZY-312 on intestinal epithelial cells were first examined, which revealed that ZY-312 inhibited CS invasion, CS-induced dual cell death (pyroptosis and apoptosis), and epithelial barrier dysfunction in vitro and in vivo. ZY-312 also decreased the expression of an inflammasome (NOD-like receptor family member pyrin domain-containing protein 3 (NLRP3), caspase-3, and serine protease caspase-1 in a neonatal rat model. Furthermore, ZY-312 significantly modulated the compositions of the intestinal bacterial communities, and decreased the relative abundances of Proteobacteria, Gamma proteobacteria, but increased the relative abundance of Bacteroides and Bacillus in neonatal rats. In conclusion, our findings have shown for the first time that the probiotic, B. fragilis ZY-312, suppresses CS-induced NEC by modulating the pro-inflammatory response and dual cell death (apoptosis and pyroptosis).Author summaryCronobacter sakazakii, a major necrotizing enterocolitis pathogen, is used as a model microorganism for the study of opportunistic bacteria in the pathogenesis of necrotizing enterocolitis. Here, we have now unequivocally demonstrated that both apoptotic and pyroptotic stimuli contribute to the pathogenesis of Cronobacter sakazakii -induced necrotizing enterocolitis. Previously, we isolated and characterized a novel probiotic, B. fragilis strain ZY-312. We found that the ZY-312 defense against Cronobacter sakazakii-induced necrotizing enterocolitis by inhibiting Cronobacter sakazakii invasion, epithelial barrier dysfunction, the expression of inflammatory cytokines and dual cell death (pyroptosis and apoptosis). This study demonstrates the utility of ZY-312 as a promising probiotic agent for the prevention and treatment of various intestinal diseases, including NEC.


2020 ◽  
Vol 23 (1) ◽  
Author(s):  
Lei Wang ◽  
You-Jin Jeon ◽  
Jae-Il Kim

Abstract Background Inflammation plays a crucial role in the pathogenesis of many diseases such as arthritis and atherosclerosis. In the present study, we evaluated anti-inflammatory activity of sterol-rich fraction prepared from Spirogyra sp., a freshwater green alga, in an effort to find bioactive extracts derived from natural sources. Methods The sterol content of ethanol extract of Spirogyra sp. (SPE) was enriched by fractionation with hexane (SPEH), resulting 6.7 times higher than SPE. Using this fraction, the in vitro and in vivo anti-inflammatory activities were evaluated in lipopolysaccharides (LPS)-stimulated RAW 264.7 cells and zebrafish. Results SPEH effectively and dose-dependently decreased the production of nitric oxide (NO) and prostaglandin E2 (PGE2). SPEH suppressed the production of pro-inflammatory cytokines including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β through downregulating nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW 264.7 cells without cytotoxicity. The in vivo test results indicated that SPEH significantly and dose-dependently reduced reactive oxygen species (ROS) generation, cell death, and NO production in LPS-stimulated zebrafish. Conclusions These results demonstrate that SPEH possesses strong in vitro and in vivo anti-inflammatory activities and has the potential to be used as healthcare or pharmaceutical material for the treatment of inflammatory diseases.


2008 ◽  
Vol 295 (2) ◽  
pp. H499-H508 ◽  
Author(s):  
Wael F. Alzawahra ◽  
M. A. Hassan Talukder ◽  
Xiaoping Liu ◽  
Alexandre Samouilov ◽  
Jay L. Zweier

Nitric oxide (NO) has been shown to be the endothelium-derived relaxing factor (EDRF), and its impairment contributes to a variety of cardiovascular disorders. Recently, it has been recognized that nitrite can be an important source of NO; however, questions remain regarding the activity and mechanisms of nitrite bioactivation in vessels and its physiological importance. Therefore, we investigated the effects of nitrite on in vivo hemodynamics in rats and in vitro vasorelaxation in isolated rat aorta under aerobic conditions. Studies were performed to determine the mechanisms by which nitrite is converted to NO. In anesthetized rats, nitrite dose dependently decreased both systolic and diastolic blood pressure with a threshold dose of 10 μM. Similarly, nitrite (10 μM-2 mM) caused vasorelaxation of aortic rings, and NO was shown to be the intermediate factor responsible for this activity. With the use of electrochemical as well as electron paramagnetic resonance (EPR) spectroscopy techniques NO generation was measured from isolated aortic vessels following nitrite treatment. Reduction of nitrite to NO was blocked by heating the vessel, suggesting that an enzymatic process is involved. Organ chamber experiments demonstrated that aortic relaxation induced by nitrite could be blocked by both hemoglobin and soluble guanylyl cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ). In addition, both electrochemical and EPR spin-trapping measurements showed that ODQ inhibits nitrite-mediated NO production. These findings thus suggest that nitrite can be a precursor of EDRF and that sGC or other heme proteins inhibited by ODQ catalyze the reduction of nitrite to NO.


Author(s):  
Eleonora Salvolini ◽  
Monia Orciani ◽  
Arianna Vignini ◽  
Roberto Primio ◽  
Laura Mazzanti

AbstractRecent reports have indicated that, as well as having antiresorptive effects, bisphosphonates could have an application as anti-inflammatory drugs. Our aim was to investigate whether this anti-inflammatory action could be mediated by the nitric oxide (NO) released by the leukocytes migrating to the site of inflammation. In particular, we investigated in vitro the intracellular calcium concentration ([Ca2+]i), the level of NO released by PMN and platelets, and the PMN myeloperoxidase activity after incubation with disodium pamidronate, since there was a postulated modulatory effect of this aminosubstituted bisphosphonate on leukocytes both in vitro and in vivo. Our data shows that the pamidronate treatment provoked a significant increase in the [Ca2+]i parallel to the enhancement in NO release, suggesting a possible activation of constitutive nitric oxide synthase, while the myeloperoxidase activity was significantly reduced. In conclusion, we hypothesized that treatment with pamidronate could stimulate NO-production by cells present near the bone compartment, thus constituting a protective mechanism against bone resorption occurring during inflammation. In addition, PMN- and platelet-derived NO could act as a negative feed-back signal to restrict the inflammatory processes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Juan A. Rubiolo ◽  
Emilio Lence ◽  
Concepción González-Bello ◽  
María Roel ◽  
José Gil-Longo ◽  
...  

Crambescins are guanidine alkaloids from the sponge Crambe crambe. Crambescin C1 (CC) induces metallothionein genes and nitric oxide (NO) is one of the triggers. We studied and compared the in vitro, in vivo, and in silico effects of some crambescine A and C analogs. HepG2 gene expression was analyzed using microarrays. Vasodilation was studied in rat aortic rings. In vivo hypotensive effect was directly measured in anesthetized rats. The targets of crambescines were studied in silico. CC and homo-crambescine C1 (HCC), but not crambescine A1 (CA), induced metallothioneins transcripts. CC increased NO production in HepG2 cells. In isolated rat aortic rings, CC and HCC induced an endothelium-dependent relaxation related to eNOS activation and an endothelium-independent relaxation related to iNOS activation, hence both compounds increase NO and reduce vascular tone. In silico analysis also points to eNOS and iNOS as targets of Crambescin C1 and source of NO increment. CC effect is mediated through crambescin binding to the active site of eNOS and iNOS. CC docking studies in iNOS and eNOS active site revealed hydrogen bonding of the hydroxylated chain with residues Glu377 and Glu361, involved in the substrate recognition, and explains its higher binding affinity than CA. The later interaction and the extra polar contacts with its pyrimidine moiety, absent in the endogenous substrate, explain its role as exogenous substrate of NOSs and NO production. Our results suggest that CC serve as a basis to develop new useful drugs when bioavailability of NO is perturbed.


2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S125-S126
Author(s):  
L HARTMANN ◽  
B Siegmund ◽  
C Weidinger ◽  
C Becker ◽  
M F Neurath ◽  
...  

Abstract Background Interferons (IFNs) are immune-modulatory cytokines expressed by epithelial and mucosal cells in response to viral and bacterial infection. Just recently, we discovered a correlation between IFN-λ expression and disease activity, including small intestinal inflammation and Paneth cell dysfunction, in human Crohn’s disease patients. On a molecular level, we uncovered that IFN-λ mediates epithelial cell death, in particular, Paneth cell death by a programmed necrosis, dependent on STAT1 activation and controlled by caspase-8. These results suggested that IFN-λ can be considered as a pathogenic cytokine in Crohn′s ileitis and should be considered as a new and promising target for future therapeutic intervention for this particular subtype of IBD. Our central question is now by which pathways interferon-regulated programmed necrosis of epithelial cells contributes to intestinal inflammation and how these mechanisms could be targeted for future therapeutic intervention. Methods We use a mouse model for Crohn’s Disease like inflammation and Paneth cell death that has a specific deletion of Caspase-8 in intestinal epithelial cells (Casp8∆IEC). We stimulate small intestinal organoids derived from Casp8∆IEC mice with IFNs in vitro and we overexpress IFN-λ in these mice in vivo by hydrodynamic tail vein injection of an IFN-λ expression vector. Furthermore, we use JAK-inhibitors to impede pharmacologically cell death pathways in the pathogenesis of intestinal inflammation in vitro and in vivo. Results We uncovered that gene expression of the cell death mediators Mlkl and Caspase-8 is dependent on IFN-λ-mediated JAK-STAT1 signalling. The non-specific pan JAK-inhibitor Tofacitinib is able to attenuate gene expression of Mlkl and Caspase-8 in vitro as well as in vivo. It prevents non-apoptotic as well as apoptotic cell death of small intestinal organoids stimulated with IFN-λ and is sufficient to prevent small intestinal tissue destruction in Casp8∆IEC mice challenged with IFN-λ. Additionally, we use the selective JAK1-inhibitor Filgotinib to limit the targeted JAK-STAT signalling pathways to only JAK1-STAT1 signalling and thus reduce side effects of the inhibitor on other signalling pathways. This had a similar effect as Tofacitinib suggesting that IFN controls MLKL-mediated cell death via JAK1. Conclusion In summary, our results indicate that targeting IFN-λ-mediated JAK-STAT1 signalling by the small-molecules Tofacitinib and Filgotinib impedes induction of Mlkl and Caspase-8-mediated cell death pathways. Therefore, JAK1 inhibitors such as Filgotinib might represent a promising novel therapy that may be sufficient to achieve efficacy particularly in Crohn′s ileitis patients who display elevated IFN-l serum levels.


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