scholarly journals Nonpathogenic Escherichia coli Strain Nissle 1917 Inhibits Signal Transduction in Intestinal Epithelial Cells

2007 ◽  
Vol 76 (1) ◽  
pp. 214-220 ◽  
Author(s):  
Nobuhiko Kamada ◽  
Kenichi Maeda ◽  
Nagamu Inoue ◽  
Tadakazu Hisamatsu ◽  
Susumu Okamoto ◽  
...  

ABSTRACT Although the probiotic Escherichia coli strain Nissle 1917 has been used for the treatment of inflammatory bowel diseases, the precise mechanisms of action of this strain remain unclear. In the present study, we estimated the anti-inflammatory effect of E. coli Nissle 1917 on inflammatory responses in vitro to determine the suppressive mechanism of Nissle 1917 on the inflammatory process. To determine the effect of E. coli Nissle 1917, the human colonic epithelial cell line HCT15 was incubated with or without E. coli Nissle 1917 or another nonpathogenic E. coli strain, K-12, and then tumor necrosis factor alpha (TNF-α)-induced interleukin-8 (IL-8) production from HCT15 cells was assessed. Enzyme-linked immunosorbent assays and real-time quantitative PCR showed that Nissle 1917 treatment suppressed TNF-α-induced IL-8 transcription and production. In addition, results from luciferase assays indicated that Nissle 1917 inhibited IL-8 promoter activity. On the other hand, these anti-inflammatory effects were not seen with E. coli K-12. In addition, heat-killed Nissle 1917 or its genomic DNA did not have this anti-inflammatory effect. Surprisingly, Nissle 1917 did not affect IL-8 transactivation pathways, such as NF-κB activation, nuclear translocation, and DNA binding, or even activation of other transcriptional factors. Furthermore, it also became evident that Nissle 1917 induced the anti-inflammatory effect without contact to epithelial cells. In conclusion, these data indicate that the nonpathogenic E. coli strain Nissle 1917 expresses a direct anti-inflammatory activity on human epithelial cells via a secreted factor which suppresses TNF-α-induced IL-8 transactivation through mechanisms different from NF-κB inhibition.

2019 ◽  
Vol 65 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Hong Xiao Cui ◽  
Xiu Rong Xu

Rabbit is susceptible to intestinal infection, which often results in severe inflammatory response. To investigate whether the special community structure of rabbit intestinal bacteria contributes to this susceptibility, we compared the inflammatory responses of isolated rabbit crypt and villus to heat-treated total bacteria in pig, chicken, and rabbit ileal contents. The dominant phylum in pig and chicken ileum was Firmicutes, while Bacteroidetes was dominant in rabbit ileum. The intestinal bacteria from rabbit induced higher expression of toll-like receptor 4 (TLR4) in rabbit crypt and villus (P < 0.05). TLR2 and TLR3 expression was obviously stimulated by chicken and pig intestinal bacteria (P < 0.05) but not by those of rabbit. The ileal bacteria from those three animals all increased the expression of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) in crypts and villus (P < 0.05). Chicken and pig ileal bacteria also stimulated the expression of anti-inflammatory factors interferon beta (IFN-β) and IL-10 (P < 0.05), while those of rabbit did not (P > 0.05). In conclusion, a higher abundance of Gram-negative bacteria in rabbit ileum did not lead to more expressive pro-inflammatory cytokines in isolated rabbit crypt and villus, but a higher percentage of Lactobacillus in chicken ileum might result in more expressive anti-inflammatory factors.


2008 ◽  
Vol 76 (10) ◽  
pp. 4737-4744 ◽  
Author(s):  
Jeffrey Fischer ◽  
Colby Suire ◽  
Hollie Hale-Donze

ABSTRACT Microsporidia are obligate intracellular parasites that are ubiquitous in nature and have been recognized as causing an important emerging disease among immunocompromised individuals. Limited knowledge exists about the immune response against these organisms, and virtually nothing is known about the receptors involved in host recognition. Toll-like receptors (TLR) are pattern recognition receptors that bind to specific molecules found on pathogens and signal a variety of inflammatory responses. In this study, we show that both Encephalitozoon cuniculi and Encephalitozoon intestinalis are preferentially recognized by TLR2 and not by TLR4 in primary human macrophages. This is the first demonstration of host receptor recognition of any microsporidian species. TLR2 ligation is known to activate NF-κB, resulting in inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α) and interleukin-8 (IL-8). We found that the infection of primary human macrophages leads to the nuclear translocation of NF-κB in as early as 1 h and the subsequent production of TNF-α and IL-8. To verify the direct role of TLR2 parasite recognition in the production of these cytokines, the receptor was knocked down in primary human macrophages using small interfering RNA. This knockdown resulted in decreases in both the nuclear translocation of NF-κB and the levels of TNF-α and IL-8 after challenge with spores. Taken together, these experiments directly link the initial inflammatory response induced by Encephalitozoon spp. to TLR2 stimulation in human macrophages.


2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Carla Marrassini ◽  
Laura Cogoi ◽  
Valeria Sülsen ◽  
Claudia Anesini

Urera aurantiaca is an Argentinean medicinal and edible species traditionally used to treat symptoms of inflammation. The aim of this study was to evaluate the anti-inflammatory activity of a methanol extract and its major compound. U. aurantiaca aerial parts were extracted with methanol by maceration. A phytochemical analysis was performed, and the extract’s major component, apigenin-7-glucuronide (A7G), was identified by spectroscopic and HPLC methods. The analysis of the inflammatory mediators nitric oxide (NO) and tumor necrosis factor alpha (TNF-α) in lipopolysaccharide- (LPS-) stimulated macrophages were used in the evaluation of the extract and the major compound anti-inflammatory effects. The extract reduced LPS-augmented NO release from 100 μg/mL (27%), reaching the highest inhibition at 1000 μg/mL (96.3%), while A7G reduced it 30.7% at 1 μg/mL, and its maximum effect was 97.1% at 10 μg/mL. In the TNF-α model, the extract at 500 and 1000 μg/mL reduced LPS-augmented TNF-α by 13.5% and 93.9%, respectively; meanwhile, A7G reduced it by 26.2% and 83.8% at 5 and 10 μg/mL, respectively. U. aurantiaca popular use was validated. In the present study, for the first time, A7G was isolated from U. aurantiaca; furthermore, A7G showed anti-inflammatory effect in the macrophage cell line RAW264.7 (ATCC) and seems to be responsible for the extract anti-inflammatory effect.


2004 ◽  
Vol 72 (9) ◽  
pp. 5308-5314 ◽  
Author(s):  
Donglai Ma ◽  
Paul Forsythe ◽  
John Bienenstock

ABSTRACT The mechanism of the apparent anti-inflammatory action of probiotic organisms is unclear. Lactobacillus reuteri is effective in inhibiting colitis in interleukin-10 (IL-10)-deficient mice. Nerve growth factor (NGF), in addition to its activity on neuronal cell growth, has significant anti-inflammatory effects in several experimental systems in vitro and in vivo, including a model of colitis. Our experiments were designed to explore the mechanism of effect of L. reuteri in the human epithelial cell lines T84 and HT29 on cytokine and NGF synthesis and IL-8 response to tumor necrosis factor alpha (TNF-α). Epithelial cells were cultured for various times with live and killed L. reuteri and examined by reverse transcription-PCR for NGF, IL-10, and TNF-α-induced IL-8 expression. An enzyme-linked immunosorbent assay was used to quantitate intracellular IL-8 and secreted product. Western blotting and confocal microscopy were used to determine the effects on IκB and NF-κB, respectively. Live but not heat-killed or gamma-irradiated L. reuteri upregulated NGF and dose dependently inhibited constitutive synthesis by T84 and HT29 cells of IL-8 and that induced by TNF-α in terms of mRNA and intracellular and secreted protein. Similarly, L. reuteri inhibited IL-8 synthesis induced by Salmonella enterica serovar Typhimurium. L. reuteri required preincubation and adherence for effect, inhibited translocation of NF-κB to the nuclei of HeLa cells, and prevented degradation of IκB. Neither cellular lysates nor media supernatants had any effect on TNF-α-induced IL-8. The conclusion is that L. reuteri has potent direct anti-inflammatory activity on human epithelial cells, which is likely to be related to the activity of ingested probiotics. L. reuteri also upregulates an unusual anti-inflammatory molecule, NGF, and inhibits NF-κB translocation to the nucleus.


2008 ◽  
Vol 15 (9) ◽  
pp. 1456-1460 ◽  
Author(s):  
Kwadwo A. Kusi ◽  
Ben A. Gyan ◽  
Bamenla Q. Goka ◽  
Daniel Dodoo ◽  
George Obeng-Adjei ◽  
...  

ABSTRACT CD163 is an acute-phase-regulated monocyte/macrophage membrane receptor expressed late in inflammation. It is involved in the haptoglobin-mediated removal of free hemoglobin from plasma, has been identified as a naturally soluble plasma glycoprotein with potential anti-inflammatory properties, and is possibly linked to an individual's haptoglobin phenotype. High levels of soluble CD163 (sCD163) in a malaria episode may therefore downregulate inflammation and curb disease severity. In order to verify this, the relationships between sCD163 levels, malaria severity, and selected inflammatory mediators (tumor necrosis factor alpha [TNF-α], interleukin-6 [IL-6], and IL-10) were assessed by enzyme-linked immunosorbent assay using plasma samples obtained from pediatric malaria patients with uncomplicated malaria (UM [n = 38]), cerebral malaria (CM [n = 52]), and severe malarial anemia (SA [n = 55]) during two consecutive malaria transmission seasons (2002 and 2003). Median sCD163 levels were higher in UM (11.9 μg/ml) patients than in SA (7.7 μg/ml; P = 0.010) and CM (8.0 μg/ml; P = 0.031) patients. Levels of sCD163 were also higher in all patient groups than in a group of 81 age-matched healthy controls. The higher sCD163/TNF-α ratio in UM patients, coupled with the fact that sCD163 levels correlated with TNF-α levels in UM patients but not in CM and SA patients, suggests inflammatory dysregulation in the complicated cases. The study showed that sCD163 levels are elevated during acute malaria. High sCD163 levels in UM patients may be due to the induction of higher-level anti-inflammatory responses, enabling them to avoid disease complications. It is also possible that UM patients simply lost their CD163 receptors from macrophages in inflammatory sites while complicated-malaria patients still had their receptors attached to activated macrophages, reflecting ongoing and higher-level inflammation associated with complicated malaria.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Bai-Lin Li ◽  
Juan-Juan Hu ◽  
Jin-Dan Xie ◽  
Chen Ni ◽  
Hui-Jun Liang ◽  
...  

Rosanortriterpenes A–B (RTA and RTB), two nortriterpenoids, are characteristic constituents in the fruits of Rosa laevigata var. leiocapus. However, pharmacological studies on these compounds are still scarce. In the present study, we aim to investigate the anti-inflammatory mechanisms associated with the effects of RTA–B in RAW264.7 macrophages and LO2 cells by detecting cell viabilities, nitric oxide (NO) production, tumour necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) production. Simultaneously, the anti-inflammatory action mechanisms of these two compounds were illustrated through western blot assay. Besides, the antihepatic fibrosis activities of these compounds have also been explored. The results demonstrated that RTA and RTB inhibited the production of NO, TNF-α, and IL-6 and suppressed liver fibrosis. RTA and RTB treatment also greatly inhibited the activation of NF-kappaB (NF-κB) pathway. Our study confirmed the promising anti-inflammatory and anti-liver fibrosis actions of RTA–B, suggesting that they might be developed as alternative and promising drugs for the treatment of hepatic inflammatory and fibrotic diseases.


2001 ◽  
Vol 280 (1) ◽  
pp. L3-L9 ◽  
Author(s):  
Chul-Gyu Yoo ◽  
Seunghee Lee ◽  
Choon-Taek Lee ◽  
Young Whan Kim ◽  
Sung Koo Han ◽  
...  

The anti-inflammatory effect of acetylsalicylic acid (ASA) has been thought to be secondary to the inhibition of prostaglandin synthesis. Because doses of ASA necessary to treat chronic inflammatory diseases are much higher than those needed to inhibit prostaglandin synthesis, a prostaglandin-independent pathway has been emerging as the new anti-inflammatory mechanism of ASA. Here, we examined the effect of ASA on the interleukin (IL)-1β- and tumor necrosis factor (TNF)-α-induced proinflammatory cytokine expression and evaluated whether this effect is closely linked to the nuclear factor (NF)-κB/IκB-α pathway. A high dose of ASA blocked IL-1β- and TNF-α-induced TNF-α and IL-8 expression, respectively. ASA inhibited TNF-α-induced activation of NF-κB by preventing phosphorylation and subsequent degradation of IκB-α in a prostanoid-independent manner. TNF-α-induced activation of IκB kinase was also suppressed by ASA pretreatment. These observations suggest that the anti-inflammatory effect of ASA in lung epithelial cells may be due to suppression of IκB kinase activity, which thereby inhibits subsequent phosphorylation and degradation of IκB-α, activation of NF-κB, and proinflammatory cytokine expression in lung epithelial cells.


2009 ◽  
Vol 20 (20) ◽  
pp. 4412-4423 ◽  
Author(s):  
Arianne L. Theiss ◽  
Aaron K. Jenkins ◽  
Ngozi I. Okoro ◽  
Jan-Michael A. Klapproth ◽  
Didier Merlin ◽  
...  

Expression of prohibitin 1 (PHB), a multifunctional protein in the cell, is decreased during inflammatory bowel disease (IBD). Little is known regarding the regulation and role of PHB during intestinal inflammation. We examined the effect of tumor necrosis factor alpha (TNF-α), a cytokine that plays a central role in the pathogenesis of IBD, on PHB expression and the effect of sustained PHB expression on TNF-α activation of nuclear factor-kappa B (NF-κB) and epithelial barrier dysfunction, two hallmarks of intestinal inflammation. We show that TNF-α decreased PHB protein and mRNA abundance in intestinal epithelial cells in vitro and in colon mucosa in vivo. Sustained expression of prohibitin in intestinal epithelial cells in vitro and in vivo (prohibitin transgenic mice, PHB TG) resulted in a marked decrease in TNF-α–induced nuclear translocation of the NF-κB protein p65, NF-κB/DNA binding, and NF-κB–mediated transcriptional activation despite robust IκB-α phosphorylation and degradation and increased cytosolic p65. Cells overexpressing PHB were protected from TNF-α–induced increased epithelial permeability. Expression of importin α3, a protein involved in p50/p65 nuclear import, was decreased in cells overexpressing PHB and in colon mucosa of PHB TG mice. Restoration of importin α3 levels sustained NF-κB activation by TNF-α during PHB transfection. These results suggest that PHB inhibits NF-κB nuclear translocation via a novel mechanism involving alteration of importin α3 levels. TNF-α decreases PHB expression in intestinal epithelial cells and restoration of PHB expression in these cells can protect against the deleterious effects of TNF-α and NF-κB on barrier function.


2021 ◽  
Vol 89 (6) ◽  
Author(s):  
Mariam Bakshi ◽  
Deborah Hebert ◽  
Connor Gulbronson ◽  
Gary Bauchan ◽  
Wenbin Tuo ◽  
...  

ABSTRACT Ostertagia ostertagi is an abomasal parasite with significant economic impact on the cattle industry. Early host immune responses are poorly understood. Here, we examined time course expression of Toll-like receptors (TLRs) in peripheral blood mononuclear cells (PBMC) during infection where PBMC macrophages (Mϕ) generated both pro- and anti-inflammatory responses when incubated with excretory/secretory products (ESP) from fourth-stage larvae (OoESP-L4) or adult worms (OoESP-Ad). First, changes in cell morphology clearly showed that both OoESP-L4 and OoESP-Ad activated PBMC-Mϕ in vitro, resulting in suppressed CD40 and increased CD80 expression. Expression of mRNAs for TLR1, -4, -5, and -7 peaked 7 days postinfection (dpi) (early L4), decreased by 19 dpi (postemergent L4 and adults) and then increased at 27 dpi (late adults). The proinflammatory cytokine tumor necrosis factor alpha (TNF-α) (transcript and protein) increased in the presence of OoESP-Ad, and the anti-inflammatory cytokine interleukin 10 (IL-10) (protein) decreased in the presence of OoESP-L4 or OoESP-Ad; however, IL-10 mRNA was upregulated, and IL-6 (protein) was downregulated by OoESP-L4. When PBMC-Mϕ were treated with ligands for TLR4 or TLR5 in combination with OoESP-Ad, the transcripts for TNF-α, IL-1, IL-6, and IL-10 were significantly downregulated relative to treatment with TLR4 and TLR5 ligands only. However, the effects of TLR2 ligand and OoESP-Ad were additive, but only at the lower concentration. We propose that O. ostertagi L4 and adult worms utilize competing strategies via TLRs and Mϕ to confuse the immune system, which allows the worm to evade the host innate responses.


2006 ◽  
Vol 50 (7) ◽  
pp. 2420-2427 ◽  
Author(s):  
Jun Wang ◽  
Hong Zhou ◽  
Jiang Zheng ◽  
Juan Cheng ◽  
Wei Liu ◽  
...  

ABSTRACT In the present study artemisinin (ART) was found to have potent anti-inflammatory effects in animal models of sepsis induced by CpG-containing oligodeoxy-nucleotides (CpG ODN), lipopolysaccharide (LPS), heat-killed Escherichia coli 35218 or live E. coli. Furthermore, we found that ART protected mice from a lethal challenge by CpG ODN, LPS, or heat-killed E. coli in a dose-dependent manner and that the protection was related to a reduction in serum tumor necrosis factor alpha (TNF-α). More significantly, the administration of ART together with ampicillin or unasyn (a complex of ampicillin and sulbactam) decreased mortality from 100 to 66.7% or 33.3%, respectively, in mice subjected to a lethal live E. coli challenge. Together with the observation that ART alone does not inhibit bacterial growth, this result suggests that ART protection is achieved as a result of its anti-inflammatory activity rather than an antimicrobial effect. In RAW264.7 cells, pretreatment with ART potently inhibited TNF-α and interleukin-6 release induced by CpG ODN, LPS, or heat-killed E. coli in a dose- and time-dependent manner. Experiments utilizing affinity sensor technology revealed no direct binding of ART with CpG ODN or LPS. Flow cytometry further showed that ART did not alter binding of CpG ODN to cell surfaces or the internalization of CpG ODN. In addition, upregulated levels of TLR9 and TLR4 mRNA were not attenuated by ART treatment. ART treatment did, however, block the NF-κB activation induced by CpG ODN, LPS, or heat-killed E. coli. These findings provide compelling evidence that ART may be an important potential drug for sepsis treatment.


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