Heat-killed probiotic bacteria differentially regulate colonic epithelial cell production of human β-defensin-2: dependence on inflammatory cytokines

The inducible antimicrobial peptide human β-defensin-2 (hBD-2) stimulated by pro-inflammatory cytokines and bacterial products is essential to antipathogen responses of gut epithelial cells. Commensal and probiotic bacteria can augment such mucosal defences. Probiotic use in the treatment of inflammatory bowel disease, however, may have adverse effects, boosting inflammatory responses. The aim of this investigation was to determine the effect of selected probiotic strains on hBD-2 production by epithelial cells induced by pathologically relevant pro-inflammatory cytokines and the role of cytokine modulators in controlling hBD-2. Caco-2 colonic intestinal epithelial cells were pre-incubated with heat-killed probiotics, i.e. Lactobacillus casei strain Shirota (LcS) or Lactobacillus fermentum strain MS15 (LF), followed by stimulation of hBD-2 by interleukin (IL)-1β and tumour necrosis factor alpha (TNF-α) in the absence or presence of exogenous IL-10 or anti-IL-10 neutralising antibody. Cytokines and hBD-2 mRNA and protein were analysed by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. LcS augmented IL-1β-induced hBD-2, whereas LF enhanced TNF-α- and suppressed IL-1β-induced hBD-2. LF enhanced TNF-α-induced TNF-α and suppressed IL-10, whereas augmented IL-1β-induced IL-10. LcS upregulated IL-1β-induced TNF-α mRNA and suppressed IL-10. Endogenous IL-10 differentially regulated hBD-2; neutralisation of IL-10 augmented TNF-α- and suppressed IL-1β-induced hBD-2. Exogenous IL-10, however, suppressed both TNF-α- and IL-1β-induced hBD-2; LcS partially rescued suppression in TNF-α- and IL-1β-stimulation, whereas LF further suppressed IL-1β-induced hBD-2. It can be concluded that probiotic strains differentially regulate hBD-2 mRNA expression and protein secretion, modulation being dictated by inflammatory stimulus and resulting cytokine environment.

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Concentration-Dependent Effects of Cobalt and Chromium Ions on Osteoarthritic Chondrocytes

Cartilage ◽

10.1177/1947603519889389 ◽

2019 ◽

pp. 194760351988938

Author(s):

Christoph Bauer ◽

Christoph Stotter ◽

Vivek Jeyakumar ◽

Eugenia Niculescu-Morzsa ◽

Bojana Simlinger ◽

...

Keyword(s):

Inflammatory Cytokines ◽

Metabolic Activity ◽

Transcriptional Activity ◽

Articular Chondrocytes ◽

Inflammatory Responses ◽

Quantitative Polymerase Chain Reaction ◽

Human Articular Chondrocytes ◽

Tnf Α ◽

Late Apoptosis ◽

Pro Inflammatory Cytokines

Objective Cobalt and chromium (CoCr) ions from metal implants are released into the joint due to biotribocorrosion, inducing apoptosis and altering gene expression in various cell types. Here, we asked whether CoCr ions concentration-dependently changed viability, transcriptional activity, and inflammatory response in human articular chondrocytes. Design Human articular chondrocytes were exposed to Co (1.02-16.33 ppm) and Cr (0.42-6.66 ppm) ions and cell viability and early/late apoptosis (annexin V and 7-AAD) were assessed in 2-dimensional cell cultures using the XTT assay and flow cytometry, respectively. Changes in chondrocyte morphology were assessed using transmitted light microscopy. The effects of CoCr ions on transcriptional activity of chondrocytes were evaluated by quantitative polymerase chain reaction (qPCR). The inflammatory responses were determined by measuring the levels of released pro-inflammatory cytokines (interleukin-1β [IL-1β], IL-6, IL-8, and tumor necrosis factor–α [TNF-α]). Results CoCr ions concentration-dependently reduced metabolic activity and induced early and late apoptosis after 24 hours in culture. After 72 hours, the majority of chondrocytes (>90%) were apoptotic at the highest concentrations of CoCr ions (16.33/6/66 ppm). SOX9 expression was concentration-dependently enhanced, whereas expression of COL2A1 linearly decreased after 24 hours. IL-8 release was enhanced proportionally to CoCr ions levels, whereas IL-1β, IL-6, and TNF-α levels were not affected by the treatments. Conclusions CoCr ions showed concentration- and time-dependent effects on articular chondrocytes. Fractions of apoptotic articular chondrocytes were proportional to CoCr ion concentrations. In addition, metabolic activity and expression of chondrocyte-specific genes were decreased by CoCr ions. Furthermore, exposure to CoCr ions caused a release of pro-inflammatory cytokines.

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Punicalagin Prevents Inflammation in LPS-Induced RAW264.7 Macrophages by Inhibiting FoxO3a/Autophagy Signaling Pathway

Nutrients ◽

10.3390/nu11112794 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2794 ◽

Cited By ~ 8

Author(s):

Cao ◽

Chen ◽

Ren ◽

Zhang ◽

Tan ◽

...

Keyword(s):

Western Blot ◽

Signaling Pathway ◽

Inflammatory Cytokines ◽

Blot Analysis ◽

Western Blot Analysis ◽

Inflammatory Responses ◽

Raw264.7 Macrophages ◽

Tnf Α ◽

Autophagy Inhibition ◽

Pro Inflammatory Cytokines

Punicalagin, a hydrolysable tannin of pomegranate juice, exhibits multiple biological effects, including inhibiting production of pro-inflammatory cytokines in macrophages. Autophagy, an intracellular self-digestion process, has been recently shown to regulate inflammatory responses. In this study, we investigated the anti-inflammatory potential of punicalagin in lipopolysaccharide (LPS) induced RAW264.7 macrophages and uncovered the underlying mechanisms. Punicalagin significantly attenuated, in a concentration-dependent manner, LPS-induced release of NO and decreased pro-inflammatory cytokines TNF-α and IL-6 release at the highest concentration. We found that punicalagin inhibited NF-κB and MAPK activation in LPS-induced RAW264.7 macrophages. Western blot analysis revealed that punicalagin pre-treatment enhanced LC3II, p62 expression, and decreased Beclin1 expression in LPS-induced macrophages. MDC assays were used to determine the autophagic process and the results worked in concert with Western blot analysis. In addition, our observations indicated that LPS-induced releases of NO, TNF-α, and IL-6 were attenuated by treatment with autophagy inhibitor chloroquine, suggesting that autophagy inhibition participated in anti-inflammatory effect. We also found that punicalagin downregulated FoxO3a expression, resulting in autophagy inhibition. Overall these results suggested that punicalagin played an important role in the attenuation of LPS-induced inflammatory responses in RAW264.7 macrophages and that the mechanisms involved downregulation of the FoxO3a/autophagy signaling pathway.

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Impact of loganin on pro-inflammatory cytokines and depression- and anxiety-like behaviors in male diabetic rats

Physiology International ◽

10.1556/2060.105.2018.2.8 ◽

2018 ◽

Vol 105 (2) ◽

pp. 116-126 ◽

Cited By ~ 2

Author(s):

M Rajabi ◽

G Mohaddes ◽

F Farajdokht ◽

S Nayebi Rad ◽

M Mesgari ◽

...

Keyword(s):

Body Weight ◽

Blood Glucose ◽

Inflammatory Cytokines ◽

Diabetic Rats ◽

Assay Method ◽

Enzyme Linked Immunosorbent Assay ◽

Depression And Anxiety ◽

Tnf Α ◽

Immobility Time ◽

Pro Inflammatory Cytokines

Behavioral disturbances are observed in most patients suffering from diabetes. According to some evidence, pro-inflammatory cytokines have a key role both in diabetes and behavioral disorders, such as anxiety and depression. In this study, the effect of chronic administration of loganin, as a bioflavonoid, was investigated on pro-inflammatory cytokines and depression- and anxiety-like behaviors in streptozotocin-induced diabetes in male Wistar rats. Blood levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were assessed by enzyme-linked immunosorbent assay method. Depression- and anxiety-like behaviors were evaluated by forced swimming test (FST), elevated plus maze (EPM), and open field test (OFT), respectively. Body weight was also measured before the interventions and after the experiments in all groups. Our findings show that loganin-treated animals had significantly lower serum concentrations of IL-6 and TNF-α compared with the diabetic group. In the EPM test, loganin treatment significantly increased the percentage of the open arm time and open arm entries. Moreover, loganin treatment significantly decreased the grooming time and restored distance traveled and center crossing in the OFT. However, it decreased immobility time in the FST. Loganin treatment also significantly restored body weight gain and attenuated blood glucose changes in the diabetic rats. These results indicate that loganin possibly alleviates depression- and anxiety-like behaviors associated with diabetes through lowering the blood glucose and pro-inflammatory cytokine levels. More research is required to show the exact mechanism of antidepressant and anxiolytic effects of loganin in diabetes.

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Evaluation of pro-inflammatory cytokines in frail Tunisian older adults

PLoS ONE ◽

10.1371/journal.pone.0242152 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0242152

Author(s):

Sonia Hammami ◽

Imen Ghzaiel ◽

Souha Hammouda ◽

Nabil Sakly ◽

Mohamed Hammami ◽

...

Keyword(s):

Older Adults ◽

Inflammatory Cytokines ◽

Geriatric Assessment ◽

Nutritional Assessment ◽

Short Form ◽

Mini Nutritional Assessment ◽

Serum Levels ◽

Enzyme Linked Immunosorbent Assay ◽

Tnf Α ◽

Pro Inflammatory Cytokines

The present study was undertaken to evaluate serum levels of pro-inflammatory cytokines in Tunisian older adults and to examine the relationships between inflammatory marker levels, geriatric, and biochemical parameters. A cross-sectional study was conducted in a population of Tunisian older adults (N = 141, aged 65 and over). Patients were recruited from the Department of Internal Medicine, Fattouma Bourguiba University Hospital (Monastir, Tunisia) and from a nursing home (Sousse, Tunisia). Comprehensive geriatric assessment, history taking and examination including functional and nutritional assessment were done for each participant. Enzyme-linked immunosorbent assay (ELISA) test was used to measure serum cytokine (TNF-α, IL-8, IL-6) levels. The modified Short Emergency Geriatric Assessment score (SEGAm) were used to classify patients as 51 very-frail, 40 frail, and 50 non-frail. The age of the participants (80 men, 61 women) ranged from 65 to 97 years. Serum levels of TNF-α, IL-8 and C-reactive protein (CRP) were significantly higher in very-frail participants compared to frail and non-frail ones. However, no significant differences in IL-6 levels were detected among frailty groups. After adjustment for age, CRP and IL-8 levels remained significantly associated with frailty. Analysis of the receiver operating characteristic (ROC) curve corresponding to IL-8 showed an area under the curve of 0.7 (p = 0.003; 95% CI [0.58–0.81]) and a predictive threshold of 5.27 pg/ml. Positive correlations were found between frailty score, IL-6, and IL-8 levels. In addition, a significant positive correlation was observed between IL-8 levels and Timed Up and Go test results. However, a negative correlation was observed between Mini Nutritional Assessment Short-Form score, IL-6 and CRP levels, as well as between Activities of Daily Living score and serum levels of TNF-α, IL-6, and CRP. In conclusion, the key findings of this study collectively support a role of pro-inflammatory cytokines, TNF-α, CRP, and especially IL-8 in the development of frailty in older adults.

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The effect of hemantane on the level of pro-inflammatory cytokines in the nigrocaudate complex of the brain of mice with experimental parkinsonism

Nauchno-prakticheskii zhurnal «Patogenez» ◽

10.25557/2310-0435.2021.02.45-49 ◽

2021 ◽

pp. 45-49

Author(s):

Н.А. Воронина ◽

В.Г. Кучеряну ◽

Л.А. Ветрилэ ◽

В.В. Голоборщева ◽

И.Г. Капица ◽

...

Keyword(s):

Inflammatory Cytokines ◽

Clinical Stage ◽

Late Phase ◽

Brain Structures ◽

Interferon Γ ◽

Nigrostriatal System ◽

Enzyme Linked Immunosorbent Assay ◽

Tnf Α ◽

Ifn Γ ◽

Pro Inflammatory Cytokines

Целью данных исследований явилось изучение влияния гимантана (N-(2-адамантил)-гексаметиленимина гидрохлорида) на уровень провоспалительных цитокинов IL-1β, IL-6, интерферона-γ (ИФН-γ) и фактора некроза опухоли-α (ФНО-α) в нигрокаудатном комплексе мышей на ранней и поздней клинической фазе экспериментального паркинсонического синдрома (ПС), для выяснения его антипаркинсонического эффекта. Методы исследования: Раннюю и позднюю клиническую фазу ПС создавали у мышей линии C57BL/6J внутрибрюшинным введением пронейротоксина 1-метил-4-фенил-1,2,3,6-тетрагидропиридина (МФТП) в дозах 12 мг/кг или 20 мг/кг по 4 инъекции с интервалом 2 часа, соответственно. Гимантан вводили мышам внутрибрюшинным в дозе 20 мг/кг, предварительно каждый раз за 30 мин до введения МФТП. Содержание цитокинов в структурах мозга мышей определяли методом иммуноферментного анализа с использованием тест-систем производства «Cloud-Clone Corporation», США и считывающего устройства «ИФА-reader» прибора «ImmunoChem-2100», США. Результаты: Показано, что уровень IL-1β, IL-6, ИФН-γ и ФНО-α в нигрокаудатном комплексе мозга мышей возрастает как на ранней, так и на поздней фазах развития ПС. Предварительное применение гимантана снижало в нигрокаудатном комплексе мышей содержание цитокинов IL-1β, ИФН-γ и ФНО-α на ранней фазе, и только одного из 4 изученных (IL-6) - на поздней фазе развития ПС. Предполагается, что антипаркинсонический эффект гимантана на ранней клинической стадии МФТП-индуцированного ПС осуществляется, в том числе, за счёт снижения уровня провоспалительных цитокинов в нигростриатной системе, предупреждая снижение жизнеспособности дофаминергических нейронов. The aim of this work was to study the effect of Hemantane (N-(2-adamantyl)-hexamethyleneimine hydrochloride) on the level of pro-inflammatory cytokines IL-1β, IL-6, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) in the nigrocaudate complex of mice in early and late clinical phases of experimental Parkinsonian syndrome (PS) to elucidate its antiparkinsonian effect. Material and methods: The early and late clinical phases of PS were created in C57BL / 6J mice by 4 intraperitoneal injections at 2-h intervals of a proneurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), at a dose of 12 mg/kg or 20 mg/kg. Hemantane was injected intraperitoneally at a dose of 20 mg/kg 30 min before each MPTP administration. Concentrations of cytokines in mouse brain structures were measured by enzyme-linked immunosorbent assay (ELISA) using Cloud-Clone Corporation (USA) test systems and an ImmunoChem-2100 (USA) ELISA reader. Results: Concentrations of IL-1β, IL-6, IFN-γ, and TNF-α in the nigrocaudate complex were increased both in the early and late phases of PS. Prior administration of hemantane reduced the content of IL-1β, IFN-γ, and TNF-α in the nigrocaudate complex at the early phase and the content of only one of the 4 studied cytokines (IL-6) at the late phase of PS. It was assumed that the antiparkinsonian effect of hemantane at the early clinical stage of MPTP-induced PS involves a decrease in proinflammatory cytokines in the nigrostriatal system, which prevents the impairment of the viability of dopaminergic neurons.

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Aging as a Risk Factor on the Immunoexpression of Pro-Inflammatory IL-1β, IL-6 and TNF-α Cytokines in Chronic Apical Periodontitis Lesions

Biology ◽

10.3390/biology11010014 ◽

2021 ◽

Vol 11 (1) ◽

pp. 14

Author(s):

Quésia Euclides Teixeira ◽

Dennis de Carvalho Ferreira ◽

Alexandre Marques Paes da Silva ◽

Lucio Souza Gonçalves ◽

Fabio Ramoa Pires ◽

...

Keyword(s):

Elderly Patients ◽

Inflammatory Cytokines ◽

Inflammatory Responses ◽

The Elderly ◽

Apical Periodontitis ◽

Middle Aged ◽

Tnf Α ◽

Significant Difference ◽

Cytokine Levels ◽

Pro Inflammatory Cytokines

Persistent inflammatory responses in the elderly may act as modifiers on the progression and repair of chronic apical periodontitis lesions (CAPLs). While the involvement of IL-1β, IL-6 and TNF-α in inflammatory responses and, particularly, in CAPL has been documented, their expression in elderly patients needs to be further characterized. Therefore, the purpose of this study was to evaluate and compare the expressions of pro-inflammatory cytokines in CAPL from elderly individuals with young/middle-aged individuals. Thirty CAPL (15 cysts and 15 granulomas) from elderly patients (>60 years) and 30 CAPL (15 cysts and 15 granuloma) from young/middle-aged individuals (20–56 years) were selected. Immunohistochemical reactions were performed against IL-1β, IL-6 and TNF-α. The slides were subdivided into five high-magnification fields and analyzed. The number of positive stains was evaluated for each antibody. There was no significant difference between the cytokines when the cysts and granuloma were compared in the two groups. In the young/middle-aged, only IL-1β showed a difference and was significantly higher in granulomas (p = 0.019). CAPL pro-inflammatory cytokine levels in the elderly were significantly higher than in young/middle-aged individuals (p < 0.05). The pro-inflammatory cytokines IL-1β, IL-6 and TNF-α were significantly higher in CAPL in the elderly compared with the young/middle-aged group. Further elaborate research studies/analyses to elucidate the reasons for and consequences of inflammation in the elderly are recommended.

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Intestinal Epithelium-Derived Luminally Released Extracellular Vesicles in Sepsis Exhibit the Ability to Suppress TNF-α and IL-17A Expression in Mucosal Inflammation

International Journal of Molecular Sciences ◽

10.3390/ijms21228445 ◽

2020 ◽

Vol 21 (22) ◽

pp. 8445

Author(s):

Michael G. Appiah ◽

Eun Jeong Park ◽

Samuel Darkwah ◽

Eiji Kawamoto ◽

Yuichi Akama ◽

...

Keyword(s):

Epithelial Cell ◽

Extracellular Vesicles ◽

Inflammatory Responses ◽

Quantitative Polymerase Chain Reaction ◽

Mucosal Inflammation ◽

Inflammatory Disorder ◽

Intestinal Epithelial ◽

Tnf Α ◽

Polymerase Chain ◽

Pro Inflammatory Cytokines

Sepsis is a systemic inflammatory disorder induced by a dysregulated immune response to infection resulting in dysfunction of multiple critical organs, including the intestines. Previous studies have reported contrasting results regarding the abilities of exosomes circulating in the blood of sepsis mice and patients to either promote or suppress inflammation. Little is known about how the gut epithelial cell-derived exosomes released in the intestinal luminal space during sepsis affect mucosal inflammation. To study this question, we isolated extracellular vesicles (EVs) from intestinal lavage of septic mice. The EVs expressed typical exosomal (CD63 and CD9) and epithelial (EpCAM) markers, which were further increased by sepsis. Moreover, septic-EV injection into inflamed gut induced a significant reduction in the messaging of pro-inflammatory cytokines TNF-α and IL-17A. MicroRNA (miRNA) profiling and reverse transcription and quantitative polymerase chain reaction (RT-qPCR) revealed a sepsis-induced exosomal increase in multiple miRNAs, which putatively target TNF-α and IL-17A. These results imply that intestinal epithelial cell (IEC)-derived luminal EVs carry miRNAs that mitigate pro-inflammatory responses. Taken together, our study proposes a novel mechanism by which IEC EVs released during sepsis transfer regulatory miRNAs to cells, possibly contributing to the amelioration of gut inflammation.

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L-Theanine Reduced the Development of Knee Osteoarthritis in Rats via Its Anti-Inflammation and Anti-Matrix Degradation Actions: In Vivo and In Vitro Study

Nutrients ◽

10.3390/nu12071988 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1988 ◽

Cited By ~ 1

Author(s):

Hui Bai ◽

Zhiheng Zhang ◽

Yue Li ◽

Xiaopeng Song ◽

Tianwen Ma ◽

...

Keyword(s):

Nitric Oxide ◽

Inflammatory Cytokines ◽

Inflammatory Responses ◽

Quantitative Polymerase Chain Reaction ◽

Hydrolytic Enzyme ◽

Enzyme Linked Immunosorbent Assay ◽

Matrix Degradation ◽

In Vivo Animal Model

The etiology of osteoarthritis (OA) is multifactorial, with no effective disease-modifying-drugs. L-theanine has been reported to inhibit inflammatory responses in some diseases and this study aimed to investigate the effect of L-theanine on Interleukin-1(IL-1)β-stimulated chondrocytes, and in an injury-induced OA rat model. Primary chondrocytes were stimulated by IL-1β (10 ng/mL) for 24 h and then co-cultured with L-theanine for 24 h. The effects of L-theanine on IL-1β-stimulated expression of pro-inflammatory cytokines and hydrolytic enzyme were analyzed using Western blotting, quantitative polymerase chain reaction (q-PCR) and enzyme-linked immunosorbent assay (ELISA) kits. An immunofluorescence assay was used to detect nuclear factor kappa B (NF-κB) phosphorylation. OA was induced by anterior cruciate ligament transection (ACLT) surgery in rats and celecoxib was used as a positive control. OA severity was measured using the Osteoarthritis Research Society International (OARSI) grading system to describe histological changes. The results showed that L-theanine decreased the expression of pro-inflammatory mediators, including cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE-2), inducible nitric oxide synthase (iNOS), and nitric oxide (NO), both in vivo and in vitro. L-theanine treatment inhibited IL-1β-induced upregulation of matrix metalloproteinases (MMP)-3 and MMP-13, as well as inhibited NF-κB p65 activation. In vivo animal model showed that L-theanine administration (200 mg/kg) significantly alleviated OA lesions and decreased OARSI score. Our data indicated that L-theanine decreased inflammatory cytokines and protected extracellular matrix degradation through inhibition of the NF-κB pathway, and L-theanine may be considered a promising therapeutic strategy in OA prevention.

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Impact of loganin on pro-inflammatory cytokines and depression- and anxiety-like behaviors in male diabetic rats

Physiology International ◽

10.1556/2060.105.2018.1.8 ◽

2018 ◽

Vol 105 (3) ◽

pp. 199-209 ◽

Cited By ~ 10

Author(s):

M Rajabi ◽

G Mohaddes ◽

F Farajdokht ◽

S Nayebi Rad ◽

M Mesgari ◽

...

Keyword(s):

Body Weight ◽

Blood Glucose ◽

Inflammatory Cytokines ◽

Diabetic Rats ◽

Assay Method ◽

Enzyme Linked Immunosorbent Assay ◽

Depression And Anxiety ◽

Tnf Α ◽

Immobility Time ◽

Pro Inflammatory Cytokines

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

Infection and Immunity ◽

10.1128/iai.01193-07 ◽

2007 ◽

Vol 76 (1) ◽

pp. 214-220 ◽

Cited By ~ 41

Author(s):

Nobuhiko Kamada ◽

Kenichi Maeda ◽

Nagamu Inoue ◽

Tadakazu Hisamatsu ◽

Susumu Okamoto ◽

...

Keyword(s):

Escherichia Coli ◽

Epithelial Cells ◽

Nuclear Translocation ◽

Inflammatory Responses ◽

Epithelial Cell Line ◽

Necrosis Factor Alpha ◽

Tnf Α ◽

Anti Inflammatory ◽

K 12 ◽

Inflammatory Effect

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.

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