Differential expression of Toll-like receptor 4 signaling pathway genes in Escherichia coli F18-resistant and – sensitive Meishan piglets

2016 ◽  
Vol 19 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Y. Liu ◽  
L.N. Gan ◽  
W.Y. Qin ◽  
S.Y. Sun ◽  
G.Q. Zhu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lymph Nodes ◽  
Signaling Pathway ◽  
Expression Profiles ◽  
Mrna Levels ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
E Coli ◽  
Significant Difference ◽  
Spleen And Lymph Nodes

Abstract The Toll-like receptor 4 (TLR4) signaling pathway is an important inflammatory pathways associated with the progression of numerous diseases. The aim of the present study was to investigate the relationship between TLR4 signaling and resistance to Escherichia coli F18 in locally weaned Meishan piglets. Using a real-time PCR approach, expression profiles were determined for key TLR4 signaling pathway genes TLR4, MyD88, CD14, IFN-α, IL-1β and TNF-α in the spleen, thymus, lymph nodes, duodenum and jejunum of E. coli F18-resistant and -sensitive animals. TLR4 signaling pathway genes were expressed in all the immune organs and intestinal tissues, and the expression was generally higher in the spleen and lymph nodes. TLR4 transcription was higher in the spleen of sensitive piglets (p<0.05), but there was no significant difference in TLR4 mRNA levels in other tissues. Similarly, CD14 transcription was higher in lymph nodes of sensitive animals (p<0.05) but not in other tissues. IL-1β expression was higher in the spleen and in the duodenum of resistant piglets (p<0.05, p<0.01, respectively), and there were no significant differences in other tissues. There were also no significant differences in the expression of MyD88, TNF-α and IFN-α between sensitive and resistant piglets (p>0.05). These results further confirm the involvement of the TLR4 signaling pathway in resistance to E. coli F18 in Meishan weaned piglets. The resistance appeared to be mediated via downregulation of TLR4 and CD14, and upregulation of MyD88 that may promote the release of cytokines TNF-α, IL-1β, IFN-α and other inflammatory mediators which help to fight against E. coli F18 infection.

scholarly journals Low-grade endotoxaemia enhances artery thrombus growth via Toll-like receptor 4: implication for myocardial infarction

2020 ◽  
Vol 41 (33) ◽  
pp. 3156-3165 ◽  
Author(s):  
Roberto Carnevale ◽  
Sebastiano Sciarretta ◽  
Valentina Valenti ◽  
Flavio di Nonno ◽  
Camilla Calvieri ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Escherichia Coli ◽  
Platelet Activation ◽  
Cathepsin G ◽  
Low Grade ◽  
Toll Like Receptor ◽  
Gut Permeability ◽  
Toll Like Receptor 4 ◽  
E Coli ◽  
St Elevation

Abstract Aims Low-grade endotoxaemia is detectable in human circulation but its role in thrombosis is still unclear. Methods and results We measured serum lipopolysaccharide (LPS) concentration, soluble P-selectin (sP-selectin), a marker of platelet activation, and zonulin, a marker of gut permeability, in peripheral circulation, coronary thrombi, and intracoronary blood of patients with ST-elevation myocardial infarction (STEMI, n = 50) and stable angina (SA) (n = 50), respectively, and in controls (n = 50). Experimental study was carried out in mice to assess if Escherichia coli-LPS (E. coli-LPS) possess thrombotic property. Coronary thrombi from STEMI showed higher concentrations of LPS, sP-selectin vs. intracoronary blood of SA and peripheral blood of controls (P &lt; 0.001). Zonulin was higher in STEMI compared to the other two groups [4.57 (3.34–5.22); 2.56 (0.41–4.36); 1.95 (1.22–2.65) ng/mL; P &lt; 0.001] and correlated with LPS (Rs = 0.585; P &lt; 0.001). Escherichia coli DNA was positive in 34% of STEMI vs. 12% of SA and 4% of controls (P &lt; 0.001). In a subgroup of 12 STEMI, immunohistochemical analysis of coronary thrombi showed positivity for leucocyte Toll-like receptor 4 (TLR4), cathepsin G, and LPS from E. coli in 100%, 80%, and 25% of samples, respectively. E. coli-LPS injected in mice to reach LPS concentrations like those detected in coronary thrombi was associated with enhanced artery thrombosis and platelet activation, an effect blunted by TLR4 inhibitor co-administration. In vitro study demonstrated that LPS from E. coli enhanced platelet aggregation via TLR4-mediated leucocyte cathepsin G activation. Conclusion ST-elevation myocardial infarction patients disclose an enhanced gut permeability that results in LPS translocation in human circulation and eventually thrombus growth at site of artery lesion via leucocyte–platelet interaction.

scholarly journals Regulatory Role of rno-miR-30b-5p in IL-10 and Toll-like Receptor 4 Expressions of T Lymphocytes in Experimental Autoimmune Uveitis In Vitro

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yuanyuan Sun ◽  
Dadong Guo ◽  
Bin Liu ◽  
Xuewei Yin ◽  
Huixia Wei ◽  
...  
Keyword(s):  
T Cells ◽  
Lymph Nodes ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Protein Levels ◽  
Eye Tissues ◽  
Spleen And Lymph Nodes ◽  
Experimental Autoimmune

Uveitis is a serious eye disease that usually damages young adult’s health. MicroRNAs (miRNAs) are a class of small noncoding RNAs which regulate messenger RNA (mRNA) expression. It is predicted that rno-miR-30b-5p can regulate the expressions of interleukin-10 (IL-10) and Toll-like receptor 4 (TLR4). In this study, the regulatory role of rno-miR-30b-5p in IL-10 and TLR4 gene expressions was validated using luciferase activity assay. Further, the inflammatory manifestation of the anterior segment and pathological examination of the eye were explored in experimental autoimmune uveitis (EAU) rats. Meanwhile, the levels of rno-miR-30b-5p in eye tissues, spleen, and lymph nodes were measured using quantitative PCR (Q-PCR). IL-10 and TLR4 in spleen and lymph nodes were further separately determined by using Q-PCR and Enzyme-Linked Immunosorbent Assay (ELISA). Moreover, rno-miR-30b-5p mimic and its inhibitor were separately transfected into purified T cells, and the levels of IL-10 and TLR4 were detected using PCR, flow cytometry, and ELISA techniques. Results indicate that rno-miR-30b-5p was downregulated in spleen, lymph nodes, and eye tissues whereas the expressions of IL-10 and TLR4 at mRNA and protein levels were upregulated. The levels of IL-10 and TLR4 were negatively correlated to rno-miR-30b-5p levels. The result of in vitro cell transfection experiment indicates that IL-10 and TLR4 expressions were inhibited at mRNA and protein levels after T cells incubated with rno-miR-30b-5p mimic. However, the IL-10 and TLR4 mRNA levels were upregulated in purified T cells from spleen and lymph nodes after treatment with miR-30b-5p antagonist. In addition, there was no evident change of IL-10 and TLR4 proteins in spleen and lymph node T cells between EAU control and negative treatment groups. Flow cytometry analysis revealed that rno-miR-30b-5p mimic could reduce the number of both IL-10 and TLR4 positive cells, whereas rno-miR-30b-5p inhibitor could increase the number of IL-10 and TLR4 positive cells. Our study demonstrates that rno-miR-30b-5p influences the development of uveitis by regulating the level of IL-10 and TLR4 positive cells, thereby playing a role in the pathogenesis of uveitis.

scholarly journals Toll-Like Receptor 4/Stem Cell Antigen 1 Signaling Promotes Hematopoietic Precursor Cell Commitment to Granulocyte Development during the Granulopoietic Response to Escherichia coli Bacteremia

2013 ◽  
Vol 81 (6) ◽  
pp. 2197-2205 ◽  
Author(s):  
Xin Shi ◽  
Robert W. Siggins ◽  
William L. Stanford ◽  
John N. Melvan ◽  
Marc D. Basson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bone Marrow ◽  
Stem Cell ◽  
Precursor Cell ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Content Type ◽  
E Coli ◽  
Hematopoietic Precursor

ABSTRACTIn response to severe bacterial infection, bone marrow hematopoietic activity shifts toward promoting granulopoiesis. The underlying cell signaling mechanisms remain obscure. To study the role of Toll-like receptor 4 (TLR4)/stem cell antigen-1 (Sca-1) signaling in this process, bacteremia was induced in mice by intravenous injection ofEscherichia coli. A subgroup of animals also received intravenous 5-bromo-2-deoxyuridine (BrdU). In a separate set of experiments, bone marrow lineage-negative (lin−) stem cell growth factor receptor-positive (c-kit+) Sca-1−cells containing primarily common myeloid progenitors were culturedin vitrowithout or withE. colilipopolysaccharide (LPS). In genotypic background control mice, bacteremia significantly upregulated Sca-1 expression by lin−c-kit+cells, as reflected by a marked increase in BrdU-negative lin−c-kit+Sca-1+cells in the bone marrow. In mice with the TLR4 gene deletion, this bacteremia-evoked Sca-1 response was blocked.In vitro, LPS induced a dose-dependent increase in Sca-1 expression by cultured marrow lin−c-kit+Sca-1−cells. LPS-induced upregulation of Sca-1 expression was regulated at the transcriptional level. Inhibition of c-Jun N-terminal kinase/stress-activated protein kinase (JNK) activity with the specific inhibitor SP600125 suppressed LPS-induced upregulation of Sca-1 expression by marrow lin−c-kit+Sca-1−cells. Engagement of Sca-1 with anti-Sca-1 antibodies enhanced the expression of Sfpi1 spleen focus-forming virus (SFFV) proviral integration 1 (PU.1) in marrow lin−c-kit+Sca-1−cells cultured with LPS. Sca-1 null mice failed to maintain the marrow pool of granulopoietic cells following bacteremia. These results demonstrate that TLR4/Sca-1 signaling plays an important role in the regulation of hematopoietic precursor cell programming and their enhancement of granulocyte lineage commitment in response toE. colibacteremia.

scholarly journals Differential expression of antioxidant genes during clinical mastitis of cow caused by Staphylococcus aureus and Escherichia coli

2021 ◽  
Vol 91 (5) ◽  
pp. 451-458
Author(s):  
Reza Asadpour ◽  
◽  
Pedram Zangiband ◽  
Katayoon Nofouzi ◽  
Adel Saberivand
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Expression Profiles ◽  
Clinical Mastitis ◽  
Mrna Levels ◽  
Antioxidant Genes ◽  
E Coli ◽  
Antioxidant Gene Expression ◽  
The Mean

There is considerable interest in the hypothesis that oxidative stress is enhanced in the pathophysiology of clinical mastitis. The main goal of this research was to establish profiles of antioxidant gene expression in the milk of cows with clinical mastitis. Standard bacteriology was conducted on pretreatment milk specimens from 77 cows with clinical mastitis between 15 and 70 days in milk (DIM). Examinations were performed on mRNA expression of antioxidant genes, such as catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD). Additionally, levels of lipid peroxidation were measured in milk samples from healthy cows and those with clinical mastitis. The isolated bacteria consisted of Staphylococcus aureus (S. aureus, 10.48%), Streptococcus agalactiae (7.69%), Streptococcus dysagalactiae (6.29%), and Escherichia coli (E. coli, 29.37%). E. coli was the most prevalent pathogen found in the milk of cows with clinical mastitis in early lactation. The mean level of malondialdehyde (MDA) in clinical mastitis samples was significantly higher (P<0.05) than that of healthy cows. The results revealed that the expression profiles of SOD in mastitis milk induced by S. aureus were significantly (P<0.0001) up-regulated compared with E.coli. In addition, the mRNA levels of GPx in mastitis milk due to E.coli were significantly (P<0.0001) over expressed compared to S. aureus. CAT gene expression had a tendency to be enhanced in mastitis milk induced by S. aureus compared with mastitis in cows due to E.coli. These results showed that the mRNA levels of antioxidant genes may differ depending on the type of bacteria, and diminished expression of antioxidant genes might increase susceptibility to mastitis.

scholarly journals The lipopolysaccharide from Escherichia coli O127:B8 induces inflammation and motility disturbances in rabbit ileum

2017 ◽  
Vol 25 (2) ◽  
pp. 185
Author(s):  
Laura Grasa ◽  
Sergio Gonzalo ◽  
Alba De Martino ◽  
María Divina Murillo
Keyword(s):  
Escherichia Coli ◽  
Mrna Expression ◽  
Intestinal Inflammation ◽  
Organ Bath ◽  
Toll Like Receptor ◽  
Rabbit Ileum ◽  
Toll Like Receptor 4 ◽  
E Coli ◽  
Mucosal Layer ◽  
Spontaneous Contractions

<p>The aim of this work was to evaluate the effects of lipopolysaccharide (LPS) from <em>Escherichia coli </em>O127:B8 on the expression of toll-like receptor 4 (TLR4), the histology, and motor function in rabbit ileum. Rabbits were injected intravenously with saline or LPS (100 μg/kg, 2 h). The mRNA expression and localization of TLR4 were determined by reverse transcriptase-PCR and immunofluorescence, respectively. Histological damage induced by LPS was evaluated in sections of ileum stained with haematoxylin and eosin. Contractility studies of ileum were performed in an organ bath. The mRNA expression of TLR4 decreased in the muscular but not in the mucosal layer of rabbits treated with LPS. TLR4 was localised in both the mucosal and muscular layers of rabbit ileum. LPS induced intestinal inflammation and altered the spontaneous contractions and the serotonin-, acetylcholine- and KCl-induced contractions. In conclusion, LPS from <em>E. coli </em>O127:B8 induced a decrease in the mRNA expression of TLR4, an inflammatory response, and changes in the contractility of rabbit ileum.</p>

scholarly journals Distribution of Lactoferrin Is Related with Dynamics of Neutrophils in Bacterial Infected Mice Intestine

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1496 ◽  
Author(s):  
Li Liang ◽  
Zhen-Jie Wang ◽  
Guang Ye ◽  
Xue-You Tang ◽  
Yuan-Yuan Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Mucosal Immunity ◽  
Mrna Levels ◽  
Iron Binding ◽  
E Coli ◽  
New Knowledge ◽  
Activated Neutrophils ◽  
Binding Glycoprotein

Lactoferrin (Lf) is a conserved iron-binding glycoprotein with antimicrobial activity, which is present in secretions that recover mucosal sites regarded as portals of invaded pathogens. Although numerous studies have focused on exogenous Lf, little is known about its expression of endogenous Lf upon bacterial infection. In this study, we investigated the distribution of Lf in mice intestine during Escherichia coli (E. coli) K88 infection. PCR and immunohistology staining showed that mRNA levels of Lf significantly increased in duodenum, ileum and colon, but extremely decreased in jejunum at 8 h and 24 h after infection. Meanwhile, endogenous Lf was mostly located in the lamina propria of intestine villi, while Lf receptor (LfR) was in the crypts. It suggested that endogenous Lf-LfR interaction might not be implicated in the antibacterial process. In addition, it was interesting to find that the infiltration of neutrophils into intestine tissues was changed similarly to Lf expression. It indicated that the variations of Lf expression were rather due to an equilibrium between the recruitment of neutrophils and degranulation of activated neutrophils. Thus, this new knowledge will pave the way to a more effective understanding of the role of Lf in intestinal mucosal immunity.

scholarly journals Role of the ceramide-signaling pathway in cytokine responses to P-fimbriated Escherichia coli.

1996 ◽  
Vol 183 (3) ◽  
pp. 1037-1044 ◽  
Author(s):  
M Hedlund ◽  
M Svensson ◽  
A Nilsson ◽  
R D Duan ◽  
C Svanborg
Keyword(s):  
Escherichia Coli ◽  
Signaling Pathway ◽  
Kinase Inhibitors ◽  
Human Kidney ◽  
Cytokine Response ◽  
Protein Kinase Inhibitors ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
Outer Leaflet

Escherichia coli express fimbriae-associated adhesins through which they attach to mucosal cells and activate a cytokine response. The receptors for E. coli P fimbriae are the globoseries of glycosphingolipids; Gal alpha 1--&gt;4Gal beta-containing oligosaccharides bound to ceramide in the outer leaflet of the lipid bilayer. The receptors for type 1 fimbriae are mannosylated glycoproteins rather than glycolipids. This study tested the hypothesis that P-fimbriated E. coli elicit a cytokine response through the release of ceramide in the receptor-bearing cell. We used the A498 human kidney cell line, which expressed functional receptors for P and type 1 fimbriae and secreted higher levels of interleukin (IL)-6 when exposed to the fimbriated strains than to isogenic nonfimbriated controls. P-fimbriated E. coli caused the release of ceramide and increased the phosphorylation of ceramide to ceramide 1-phosphate. The IL-6 response to P-fimbriated E. coli was reduced by inhibitors of serine/threonine kinases but not by other protein kinase inhibitors. In contrast, ceramide levels were not influenced by type 1-fimbriated E. coli, and the IL-6 response was insensitive to the serine/threonine kinase inhibitors. These results demonstrate that the ceramide-signaling pathway is activated by P-fimbriated E. coli, and that the receptor specificity of the P fimbriae influences this process. We propose that this activation pathway contributes to the cytokine induction by P-fimbriated E. coli in epithelial cells.

scholarly journals Distribution of Sulfonamide Resistance Genes in Escherichia coli and Salmonella Isolates from Swine and Chickens at Abattoirs in Ontario and Québec, Canada

2009 ◽  
Vol 75 (18) ◽  
pp. 5999-6001 ◽  
Author(s):  
Gosia K. Kozak ◽  
David L. Pearl ◽  
Julia Parkman ◽  
Richard J. Reid-Smith ◽  
Anne Deckert ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
E Coli ◽  
Significant Difference ◽  
Sulfonamide Resistance ◽  
Sulfonamide Resistance Genes

ABSTRACT Sulfonamide-resistant Escherichia coli and Salmonella isolates from pigs and chickens in Ontario and Québec were screened for sul1, sul2, and sul3 by PCR. Each sul gene was distributed differently across populations, with a significant difference between distribution in commensal E. coli and Salmonella isolates and sul3 restricted mainly to porcine E. coli isolates.

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