scholarly journals Evaluation of E. coli Nissle1917 derived metabolites in modulating key mediator genes of the TLR signaling pathway

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sheyda Damoogh ◽  
Mehrad Vosough ◽  
Shima Hadifar ◽  
Masoumeh Rasoli ◽  
Ali Gorjipour ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Signaling Pathway ◽  
Tlr Signaling ◽  
E Coli ◽  
Tnf Α ◽  
Different Types ◽  
Health And Illness ◽  
Inflammatory Bowel ◽  
Dose Dependent ◽  
Tlr Signaling Pathway

Abstract Objective Gut-microbiota plays key roles in many aspects like the health and illness of humans. It's well proved that modification of gut microbiota by probiotics is useful for improving inflammatory bowel disease (IBD) conditions. According to recent studies, different types of bacterial metabolites can affect immune cells and inflammation conditions. The present study aimed to evaluate the anti-inflammatory effects of metabolites of E. coli Nissle1917. Results The cell-free supernatant could modulate TNF-α production and affected many crucial mediators in the Toll-like receptor (TLR) signaling pathway. Also, supernatant showed significant dose-dependent properties in this regard. In this study, the TLR signaling pathway was found among probable mechanisms by which probiotics can affect inflammatory situations. These findings provide additional evidence on the use of probiotic metabolites for inhibiting and down-regulating numerous key mediator factors in the TLR signaling pathway. Aberrant or dysfunctional TLR signaling contributes to the development of acute and chronic intestinal inflammatory pathways in IBD. Therefore, finding a component that can affect this process might be considered for therapeutic targets in IBD patients.

Role of microbiota and Toll-like receptors in progression of esophageal adenocarcinoma (EAC) in a rat reflux model.

2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 28-28 ◽  
Author(s):  
Lori A Kelly ◽  
Ali H Zaidi ◽  
Mark Barlek ◽  
Rachael Kreft ◽  
Ashten Omstead ◽  
...  
Keyword(s):  
Gene Expression ◽  
Signaling Pathway ◽  
Direct Proof ◽  
Acid Reflux ◽  
Toll Like Receptor ◽  
Tlr Signaling ◽  
Molecular Sequence ◽  
E Coli ◽  
Post Surgery ◽  
Tlr Signaling Pathway

28 Background: The discovery of the link between H. pylori and gastric cancer may be the most direct proof that bacterial signaling and host response can result in carcinogenesis. Accumulating evidence supports that activation of the Toll-like receptor (TLR) signaling pathway by microbes is associated with the development of GI malignancies. Using the modified Levrat model of gastroduodenojejunal reflux which mimics the physiological and molecular sequence of human EAC in the rat, this study profiles the expression of genes central to TLR-mediated signal transduction as well as characterizes the esophageal microbiome across the spectrum of EAC development. Methods: Modified Levrat’s surgery induced chronic acid reflux in Sprague-Dawley’s with harvest of esophagus 40 weeks post-surgery. Macordissection of normal adjacent epithelium, Barrett’s esophagus (BE), dysplasia and EAC tumor was performed followed by RNA/DNA isolation. Five samples per group were selected for gene expression profiling on the Qiagen TLR Signaling Pathway PCR Array as well as microbiome analysis by IBIS technology. Validation of IBIS was performed by fluorescence in situ hybridization (FISH). Results: Gene expression analysis identified TLRs 1-3 and 6, 7, 9 as significantly upregulated in EAC compared to normal esophagus. TLR 1 and 5 were significantly upregulated in dysplasia. TLR 1 was significantly upregulated in BE and normal adjacent epithelium. Thirty seven genes involved in the TLR signaling pathway were dysregulated in EAC, 30 in dysplasia, 21 in BE and 23 in normal adjacent. IBIS analysis revealed a prevalence of E. coli in BE and EAC which was validated by FISH. Conclusions: Toll-like receptor (TLR) signaling pathway responses to E. coli may participate in the development of EAC. E. coli may be a potential risk factor for EAC requiring further clinical validation.

scholarly journals Polysaccharide from Patinopecten yessoensis Skirt Boosts Immune Response via Modulation of Gut Microbiota and Short-Chain Fatty Acids Metabolism in Mice

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2478
Author(s):  
Ying Li ◽  
Juan Qin ◽  
Yinghui Cheng ◽  
Yuqing Ai ◽  
Zhiyi Han ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Immune Response ◽  
Gut Microbiota ◽  
Signaling Pathway ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Tlr Signaling ◽  
Patinopecten Yessoensis ◽  
Tlr Signaling Pathway ◽  
Chain Fatty Acids

Polysaccharide from marine shellfish has various bioactivities. In this study, the effects of polysaccharide from Patinopecten yessoensis skirt (PS) on boosting immune response in mice were evaluated, and the potential mechanisms were explored. The results showed that PS administration effectively increased the serum IgG and IgM levels, implying that PS had immune response-boosting properties. Moreover, PS administration could modulate the composition of the gut microbiota, and significantly improve short-chain fatty acids (SCFAs) metabolism, especially butyrate metabolism. Of note, the expression of the Tlr2, Tlr7, MyD88, Tnfa, and Il1b genes in toll-like receptor (TLR) signaling pathway was significantly increased. In summary, PS could boost immune response by modulating the gut microbiota and SCFAs metabolism correlating with the activation of the TLR signaling pathway. Therefore, PS can be developed as a special ingredient for functional product.

scholarly journals Up-Regulation of HMGB1 Exacerbates Renal Ischemia-Reperfusion Injury by Stimulating Inflammatory and Immune Responses through the TLR4 Signaling Pathway in Mice

2017 ◽  
Vol 41 (6) ◽  
pp. 2447-2460 ◽  
Author(s):  
Chuan-Bao Chen ◽  
Long-Shan Liu ◽  
Jian Zhou ◽  
Xiao-Ping Wang ◽  
Ming Han ◽  
...  
Keyword(s):  
Immune Responses ◽  
Signaling Pathway ◽  
Tissue Damage ◽  
Kidney Tissue ◽  
Cell Infiltration ◽  
Tlr Signaling ◽  
Tlr4 Signaling ◽  
Tnf Α ◽  
Ifn Γ ◽  
Tlr Signaling Pathway

Background/Aims: The aim of this study was to elucidate how high-mobility group box 1 (HMGB1) exacerbates renal ischemic-reperfusion injury (IRI) by inflammatory and immune responses through the toll-like receptor 4 (TLR4) signaling pathway. Methods: A total of 30 wild-type (WT) mice and 30 TLR4 knockout (TLR4-/-) mice were selected and then randomly assigned to the Sham, I/R or HMGB1 groups. The serum and kidney tissues of all mice were collected 24 h after the perfusion. The fully automatic biochemical detector and ELISA were applied to determine the blood urea nitrogen (BUN) and serum creatinine (Scr) levels, and TNF-α, IL-1β, IL-6, IFN-γ and IL-10 levels, respectively. HE staining was used to evaluate kidney tissue damage, immunofluorescence and immunohistochemical staining were performed to observe CD68 and MPO cell infiltration, and flow cytometry was applied to detect immune cells. qRT-PCR and Western blotting were used to detect the expressions of TLR signaling pathway-related genes and proteins, respectively. Results: Compared with the Sham group, the levels of BUN, Scr, TNF-α, IL-1β, IL-6, IFN-γ and IL-10, kidney tissue damage score, CD68 and MPO cell infiltration, the numbers of immune cells, and the expressions of TLR signaling pathway-related genes and proteins in the I/R and HMGB1 groups were significantly up-regulated. In the I/R and HMGB1 groups, the levels of BUN and Scr, TNF-α, IL-1β, IL-6 and IFN-γ, kidney tissue damage score, CD68 and MPO cell infiltration, immune cell numbers, and TLR signaling pathway-related gene and protein expressions in the WT mice were all higher than those in the TLR4-/- mice, but IL-10 level was significantly lower. Similarly, all aforementioned indexes but IL-10 level in the WT and TLR4-/- mice were higher in the HMGB1 group than in the I/R group. Conclusion: Our study indicated that the up-regulation of HMGB1 could exacerbate renal IRI by stimulating inflammatory and immune responses through the TLR4 signaling pathway.c

scholarly journals MicroRNA-34a Inhibition of the TLR Signaling Pathway Via CXCL10 Suppresses Breast Cancer Cell Invasion and Migration

2018 ◽  
Vol 46 (3) ◽  
pp. 1286-1304 ◽  
Author(s):  
Min Xu ◽  
Dong Li ◽  
Chen Yang ◽  
Jian-Song Ji
Keyword(s):  
Breast Cancer ◽  
Signaling Pathway ◽  
Migration And Invasion ◽  
Loss Of Function ◽  
Breast Tumorigenesis ◽  
Tlr Signaling ◽  
T47d Cells ◽  
Tlr Signaling Pathway ◽  
Mcf 7

Background/Aims: Breast cancer (BC) starts as a local disease, but it can metastasize to the lymph nodes and distant organs. However, the metastatic process is still poorly understood. The mRNA microarray datasets GSE26910 and GSE33447 show that CXCL10 is up-regulated in BC, and the microRNA microarray dataset GSE38167 and a network meta-analysis of microRNA expression profile studies in human BC suggest that microRNA-34a (miR-34a) is down-regulated in BC. CXCL10 was predicted as a target of miR-34a by microRNA.org. In this study, we uncovered a CXCL10-independent mechanism by which miR-34a exerts its antimetastatic activity in BC. Methods: To investigate the clinical significance of miR-34a in BC, we collected cancer tissues and paracancerous tissues from 258 patients with BC. In addition, a series of inhibitors, mimics, and siRNAs was introduced into MCF-7 and T47D cells to validate the regulatory mechanisms by which miR-34a regulates CXCL10. Next, to better understand the pivotal role of TLR signaling pathway inhibition in MCF-7 and T47D cells, we blocked the TLR signaling pathway using OxPAPC, an antagonist of TLR signaling. Results: Among BC patients, miR-34a was down-regulated, CXCL10 was up-regulated, and the TLR signaling pathway was activated. Determination of luciferase activity revealed that CXCL10 was a target of miR-34a. Through gain- and loss-of-function studies, miR-34a was demonstrated to negatively regulate CXCL10; inhibit activation of the TLR signaling pathway; significantly suppress in vitro cell proliferation, migration, and invasion; and induce apoptosis. Conclusion: Our findings suggest that functional loss or suppression of the tumor suppressor CXCL10 due to induction of miR-34a leads to inhibition of the TLR signaling pathway during breast tumorigenesis, providing a novel target for the molecular treatment of breast malignancies.

scholarly journals NF-κB mediates lipopolysaccharide-induced alternative pre-mRNA splicing of MyD88 in mouse macrophages

2020 ◽  
Vol 295 (18) ◽  
pp. 6236-6248
Author(s):  
Frank Fang-Yao Lee ◽  
Kevin Davidson ◽  
Chelsea Harris ◽  
Jazalle McClendon ◽  
William J. Janssen ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Chronic Inflammation ◽  
Mrna Splicing ◽  
Dominant Negative ◽  
Mrna Isoforms ◽  
Inflammatory Signaling ◽  
Tlr Signaling ◽  
Tlr4 Agonist ◽  
Alternatively Spliced ◽  
Tlr Signaling Pathway

Although a robust inflammatory response is needed to combat infection, this response must ultimately be terminated to prevent chronic inflammation. One mechanism that terminates inflammatory signaling is the production of alternative mRNA splice forms in the Toll-like receptor (TLR) signaling pathway. Whereas most genes in the TLR pathway encode positive mediators of inflammatory signaling, several, including that encoding the MyD88 signaling adaptor, also produce alternative spliced mRNA isoforms that encode dominant-negative inhibitors of the response. Production of these negatively acting alternatively spliced isoforms is induced by stimulation with the TLR4 agonist lipopolysaccharide (LPS); thus, this alternative pre-mRNA splicing represents a negative feedback loop that terminates TLR signaling and prevents chronic inflammation. In the current study, we investigated the mechanisms regulating the LPS-induced alternative pre-mRNA splicing of the MyD88 transcript in murine macrophages. We found that 1) the induction of the alternatively spliced MyD88 form is due to alternative pre-mRNA splicing and not caused by another RNA regulatory mechanism, 2) MyD88 splicing is regulated by both the MyD88- and TRIF-dependent arms of the TLR signaling pathway, 3) MyD88 splicing is regulated by the NF-κB transcription factor, and 4) NF-κB likely regulates MyD88 alternative pre-mRNA splicing per se rather than regulating splicing indirectly by altering MyD88 transcription. We conclude that alternative splicing of MyD88 may provide a sensitive mechanism that ensures robust termination of inflammation for tissue repair and restoration of normal tissue homeostasis once an infection is controlled.

scholarly journals Functional Toll-Like Receptors (TLRs) Are Expressed by a Majority of Primary Human Acute Myeloid Leukemia Cells and Inducibility of the TLR Signaling Pathway Is Associated with a More Favorable Phenotype

Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 973 ◽  
Author(s):  
Annette K. Brenner ◽  
Øystein Bruserud
Keyword(s):  
Acute Myeloid Leukemia ◽  
Signaling Pathway ◽  
Myeloid Leukemia ◽  
Receptor Expression ◽  
Cytokine Secretion ◽  
Toll Like Receptors ◽  
Tlr Signaling ◽  
General Response ◽  
Tlr Signaling Pathway ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a highly heterogeneous disease with regard to biological characteristics and receptor expression. Toll-like receptors (TLRs) are upstream to the transcription factor NFκB and part of the innate immune system. They are differentially expressed on AML blasts, and during normal hematopoiesis they initiate myeloid differentiation. In this study, we investigated the response upon TLR stimulation in an AML cohort (n = 83) by measuring the increase of NFκB-mediated cytokine secretion. We observed that TLR4 is readily induced in most patients, while TLR1/2 response was more restricted. General response to TLR stimulation correlated with presence of nucleophosmin gene mutations, increased mRNA expression of proteins, which are part of the TLR signaling pathway and reduced expression of transcription-related proteins. Furthermore, signaling via TLR1/2 appeared to be linked with prolonged patient survival. In conclusion, response upon TLR stimulation, and especially TLR1/2 induction, seems to be part of a more favorable phenotype, which also is characterized by higher basal cytokine secretion and a more mature blast population.

scholarly journals The Effects of Paclitaxel and Metformin and Combined Treatments on TLR Signaling Pathway on MDA-MB-231 Breast Cancer Cell Lines

Proceedings ◽  
2017 ◽  
Vol 1 (10) ◽  
pp. 1016 ◽  
Author(s):  
Melike Ozgul ◽  
Elgin Turkoz Uluer ◽  
Tuna Onal ◽  
Damla Akogullari ◽  
Kemal Ozbilgin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Cancer Cell Lines ◽  
Breast Cancer Cell Lines ◽  
Combined Treatments ◽  
Tlr Signaling ◽  
Tlr Signaling Pathway

The Zinc Finger Protein Gfi1 Controls TLR4-Mediated Inflammatory Response by Directly Antagonizing NF-κB Transcription Factor

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 469-469
Author(s):  
Ehssan Sharif-Askari ◽  
Hui Zeng ◽  
Lothar Vassen ◽  
Christian Kosan ◽  
Cyrus Khandanpour ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Direct Interaction ◽  
Innate Immune ◽  
Dependent Manner ◽  
Negative Regulators ◽  
Tlr Signaling ◽  
Tnf Α ◽  
Dose Dependent ◽  
Lps Treatment ◽  
Stimulation Of

Abstract Inflammatory responses are complex and comprise multiple mediators including cytokines such as TNF-alpha (TNF-α) and IL-1beta. These cytokines are synthesized and secreted in response to signaling by plasma membrane receptors of the Toll-like receptor (TLR) family. A central downstream element of TLR-dependent signaling is the transcription factor NF-kappaB (NF-κB), which plays a pivotal role in controlling the proper sequence of events during an inflammatory response. In unstimulated cells, NF-κB is bound to inhibitory IkappaB (IκB) proteins and remains sequestered in the cytoplasm. Stimulation of TLRs triggers a signaling cascade that leads to phosphorylation and proteasomal degradation of IκB, resulting in the translocation of NF-κB to the nucleus, where it acts as a transcriptional activator of target genes. To keep the innate immune system under control, the TLR signaling cascade is under a tight control of many positive and negative regulators. We have previously shown that the transcription factor Growth Factor Independence 1 (Gfi1) represents a novel factor limiting the inflammatory immune response including TNF-α. Gfi1-deficient (Gfi1−/−) mice show a very strong systemic response to the TLR4 ligand and endotoxin LPS and die rapidly within 36 h with symptoms of septic shock. Here, we investigated the molecular mechanism of this exaggerated TNF-α production in the absence of Gfi1. It is known that endotoxin stimulation results in the activation of the transcription factor NF-κB through TLR4, leading to TNF-α production. This activation also resulted in rapid and de novo expression of Gfi1 in the nucleus in a time- and dose-dependent manner. The expression of Gfi1 was not due to feedback regulation from secreted TNF, since TNF-deficient macrophages were also able to upregulate Gfi1 mRNA following LPS stimulation. As expected, LPS stimulation of Gfi1−/− macrophages resulted in significantly higher levels of TNF-α mRNA, and secreted TNF-α cytokine. Strikingly and in contrast to most known negative regulators of TLRs, Gfi1 did not affect the activity or the expression levels of the cytoplasmic components of TLR signaling pathway. Additionally, NF-κB phosphorylation and nuclear translocation post- LPS treatment were intact in both Gfi1−/− and Gfi1+/+ macrophages. Immunoprecipitation analysis from cells endogenously expressing Gfi1 and NF-κB or over-expressing these two proteins post transfection, clearly revealed a direct interaction between Gfi1 and the p65 subunit of NF-κB. Immunofluorescence staining of macrophages post-LPS treatment confirmed direct interaction of these two proteins in the nucleus at the endogenous level. Gfi1 represses transcription by binding to DNA recognition sequences in target gene promoters. Thus, aiming to investigate the effect of Gfi1 expression on NF-κB nuclear signaling, we found that LPS treatment enhances NF-κB DNA binding activity in Gfi1−/− macrophages as compared to Gfi1+/+ cells. Furthermore, over expression of Gfi1 protein resulted in negative regulation of NF-κB mediated gene activation in a dose-dependent manner. Chromatin immune precipitation with anti-p65 antibodies from LPS stimulated Gfi1+/+ and Gfi1−/− macrophages revealed enhanced NF-κB promoter occupancy at the TNF gene in Gfi1−/− macrophages as compared to Gfi1+/+ cells. In conclusion, our findings reveal a novel function for Gfi1 in the innate immune response by directly antagonizing NF-κB function. This molecular perceptive of TNF-α regulation during inflammation may provide an attractive strategy for therapeutic intervention in chronic inflammatory diseases and certain cancers.

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