scholarly journals microRNA-29a-3p, Up-Regulated in Human Gastric Cells and Tissues with H.Pylori Infection, Promotes the Migration of GES-1 Cells via A20-Mediated EMT Pathway

2018 ◽  
Vol 51 (3) ◽  
pp. 1250-1263 ◽  
Author(s):  
Fengying Sun ◽  
Ying Ni ◽  
Hong Zhu ◽  
Jian Fang ◽  
Hua Wang ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Western Blotting ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Human Gastric Mucosa ◽  
Gastric Epithelial Cells ◽  
Migration Ability ◽  
Gastric Cells ◽  
Dose Dependent

Background/Aims: Helicobacter pylori (H. pylori) infection is closely related to human gastric mucosa-associated diseases. Several recent studies on miRNAs have expanded our insights on H.pylori pathogenesis. This study aimed to investigate the biological roles and underlying molecular mechanisms of miR-29a-3p in human gastric cells and tissues with H.pylori infection. Methods: miR-29a-3p expression was quantified by quantitative RT-PCR (qRT-PCR). A miR-29a-3p target gene was validated by bioinformatics analysis, western blotting and dual luciferase reporter gene assays. Western blotting and immunohistochemistry (IHC) assay were performed to detect the protein expression. Transwell assay was used to determine the cell migration ability. Results: MiR-29a-3p was up-regulated in H.pylori-positive gastric mucosa tissues and H.pylori-infected gastric cells. The up-regulation of miR-29a-3p was dose-dependent in BGC-823 and GES-1 cells infected with H.pylori. Using gain- and loss-of-function experiments in vitro, we demonstrated that miR-29a-3p promoted the migration of gastric epithelial cells. We further characterized A20 as a direct target of miR-29a-3p. The expression of A20 was decreased in H.pylori-positive gastric mucosa tissues compared with H.pylori-negative gastric mucosa tissues. A20 downregulation was time- and dose-dependent in GES-1 and BGC-823 cells infected with H.pylori. In GES-1 and BGC-823 cells infected with H.pylori, the miR-29a-3p mimic significantly blocked A20 expression, which suggests that H.pylori decreased A20 expression through up-regulating miR-29a-3p in GES-1 and BGC-823 cells infected with H.pylori. The knockdown of A20 by siRNA enhanced the migration of human gastric epithelial cells and promoted the expression of Snail, Vimentin, and N-cadherin and inhibited the expression of E-cadherin. Conclusion: The miR-29a-3p may act as a tumor promotive miRNA by regulating cells migration through directly targeting of A20 gene in human gastric epithelial cells infected with H.pylori.

scholarly journals Expression of claudins in the normal canine gastric mucosa

2014 ◽  
Vol 62 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Roland Psáder ◽  
Csaba Jakab ◽  
Ákos Máthé ◽  
Gyula Balka ◽  
Kinga Pápa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Apical Part ◽  
Basal Part ◽  
Gastric Epithelial Cells ◽  
Gastric Glands ◽  
Gastric Cells ◽  
Pyloric Stomach ◽  
Mucous Neck Cells

The aim of the present study was to investigate the expression pattern of claudin-1, -2, -3, -4, -5, -7, -8, -10 and -18 in the intact fundic and pyloric gastric mucosa of dogs. Intense, linear, membranous claudin-18 positivity was detected in the surface gastric cells and in the epithelial cells of the gastric glands both in the fundic and pyloric stomach regions. The mucous neck cells in the apical part of the glands, furthermore the parietal cells and chief cells of the basal part of the gland were all positive for claudin-18, in the same way as the enteroendocrine cells. Cells of the basal part of the pyloric glands showed intense, linear, membranous claudin-2 positivity, but cells of the superficial portion of these glands and the surface gastric cells in this region were claudin-2 negative. Fibroblasts, endothelial cells, lymphocytes of the propria layer, smooth muscle cells and vegetative neurons were all negative for claudin-2. All gastric epithelial cells were negative for claudin-1, -3, -4, -5, -6, -7, -8 and -10. The endothelial cells of the propria layer had intense claudin-5 positivity. We assume that claudin-18 forms a paracellular barrier against gastric acid in the healthy canine stomach, in the same way as in mice.

scholarly journals Helicobacter pylori Induces RANTES through Activation of NF-κB

2003 ◽  
Vol 71 (7) ◽  
pp. 3748-3756 ◽  
Author(s):  
Naoki Mori ◽  
Alan M. Krensky ◽  
Romas Geleziunas ◽  
Akihiro Wada ◽  
Toshiya Hirayama ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Intracellular Signaling ◽  
Interleukin 1 ◽  
Luciferase Reporter ◽  
Transcriptional Level ◽  
Gastric Epithelial Cells ◽  
Rantes Promoter ◽  
H Pylori

ABSTRACT Helicobacter pylori-infected gastric mucosa displays a conspicuous infiltration of mononuclear cells and neutrophils. RANTES (short for “regulated upon activation, normal T cell expressed and secreted”) is a chemoattractant cytokine (chemokine) important in the infiltration of T lymphocytes and monocytes. RANTES may therefore contribute to the cellular infiltrate in the H. pylori-infected gastric mucosa. The aim of this study was to analyze the molecular mechanism responsible for H. pylori-mediated RANTES expression. We observed that gastric epithelial cells produced RANTES upon coculture with H. pylori. In addition, H. pylori induced RANTES mRNA expression and an increase in luciferase activity in cells which were transfected with a luciferase reporter construct derived from the RANTES promoter, in gastric epithelial cells, indicating that the induction of RANTES production occurred at the transcriptional level. Induction of RANTES was dependent on an intact cag pathogenicity island. Activation of the RANTES promoter by H. pylori occurred through the action of NF-κB. Transfection of kinase-deficient mutants of IκB kinase (IKK) and NF-κB-inducing kinase (NIK) inhibited H. pylori-mediated RANTES activation. In contrast, tumor necrosis factor alpha- or interleukin-1/Toll-like receptor signaling molecules—such as mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1, MyD88, and interleukin-1 receptor-associated kinase—did not play a role in RANTES activation by H. pylori. Collectively, H. pylori induced NF-κB activation through an intracellular signaling pathway that involved IKK and NIK, leading to RANTES gene transcription. RANTES induction by H. pylori may play an important role in gastric inflammation.

Toll-like receptor (TLR) 2 induced through TLR4 signaling initiated byHelicobacter pyloricooperatively amplifies iNOS induction in gastric epithelial cells

2007 ◽  
Vol 293 (5) ◽  
pp. G1004-G1012 ◽  
Author(s):  
Kaname Uno ◽  
Katsuaki Kato ◽  
Tomoaki Atsumi ◽  
Takehito Suzuki ◽  
Jun Yoshitake ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Innate Immune ◽  
Human Gastric Mucosa ◽  
Gastric Epithelial Cells ◽  
Tlr4 Signaling ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
H Pylori ◽  
Inos Induction

Cell-surface Toll-like receptors (TLRs) initiate innate immune responses, such as inducible nitric oxide synthase (iNOS) induction, to microorganisms' surface pathogens. TLR2 and TLR4 play important roles in gastric mucosa infected with Helicobacter pylori ( H. pylori), which contains lipopolysaccharide (LPS) as a pathogen. The present study investigates their physiological roles in the innate immune response of gastric epithelial cells to H. pylori-LPS. Changes in the expression of iNOS, TLR2, and TLR4, as well as downstream activation of mitogen-activated protein kinases and nuclear factor-κB (NF-κB), were analyzed in normal mouse gastric mucosal GSM06 cells following stimulation with H. pylori-LPS and interferon-γ. Specific inhibitors for mitogen-activated protein kinases, NF-κB, and small interfering RNA for TLR2 or TLR4 were employed. The immunohistochemistry of TLR2 was examined in human gastric mucosa. H. pylori-LPS stimulation induced TLR2 in GSM06 cells, but TLR4 was unchanged. TLR2 induction resulted from TLR4 signaling that propagated through extracellular signal-related kinase and NF-κB activation, as corroborated by the decline in TLR4 expression on small interfering RNA treatment and pretreatment with inhibitors. The induction of iNOS and the associated nitric oxide production in response to H. pylori-LPS stimulation were inhibited by declines in not only TLR4 but also TLR2. Increased expression of TLR2 was identified in H. pylori-infected human gastric mucosa. TLR4 signaling initiated by H. pylori-LPS and propagated via extracellular signal-regulated kinase and NF-κB activation induced TLR2 expression in gastric epithelial cells. Induced TLR2 cooperated with TLR4 to amplify iNOS induction. This positive correlation may constitute a mechanism for stimulating the innate immune response against various bacterial pathogens, including H. pylori-LPS.

scholarly journals Suppression of IL-8 production in gastric epithelial cells by MUC1 mucin and peroxisome proliferator-associated receptor-γ

2012 ◽  
Vol 303 (6) ◽  
pp. G765-G774 ◽  
Author(s):  
Yong Sung Park ◽  
Wei Guang ◽  
Thomas G. Blanchard ◽  
K. Chul Kim ◽  
Erik P. Lillehoj
Keyword(s):  
Epithelial Cells ◽  
Negative Control ◽  
Luciferase Reporter ◽  
Peroxisome Proliferator ◽  
Apical Surface ◽  
Gastric Epithelial Cells ◽  
Luciferase Reporter Gene ◽  
Ags Cells ◽  
Pparγ Agonist ◽  
H Pylori

MUC1 is a membrane-tethered mucin expressed on the apical surface of epithelial cells. Our previous report (Guang W, Ding H, Czinn SJ, Kim KC, Blanchard TG, Lillehoj EP. J Biol Chem 285: 20547–20557, 2010) demonstrated that expression of MUC1 in AGS gastric epithelial cells limits Helicobacter pylori infection and reduces bacterial-driven IL-8 production. In this study, we identified the peroxisome proliferator-associated receptor-γ (PPARγ) upstream of MUC1 in the anti-inflammatory pathway suppressing H. pylori- and phorbol 12-myristate 13-acetate (PMA)-stimulated IL-8 production. Treatment of AGS cells with H. pylori or PMA increased IL-8 levels in cell culture supernatants compared with cells treated with the respective vehicle controls. Prior small interfering (si)RNA-induced MUC1 silencing further increased H. pylori - and PMA-stimulated IL-8 levels compared with a negative control siRNA. MUC1-expressing AGS cells pretreated with the PPARγ agonist troglitazone (TGN) had reduced H. pylori - and PMA-stimulated IL-8 levels compared with cells treated with H. pylori or PMA alone. However, following MUC1 siRNA knockdown, no differences in IL-8 levels were seen between TGN/ H. pylori and H. pylori -only cells or between TGN/PMA and PMA-only cells. Finally, TGN-treated AGS cells had increased Muc1 promoter activity, as measured using a Muc1-luciferase reporter gene, and greater MUC1 protein levels by Western blot analysis, compared with vehicle controls. These results support the hypothesis that PPARγ stimulates MUC1 expression by AGS cells, thereby attenuating H. pylori - and PMA-induced IL-8 production.

Secretin regulates paracellular permeability in canine gastric monolayers by a Src kinase-dependent pathway

2002 ◽  
Vol 283 (4) ◽  
pp. G893-G899 ◽  
Author(s):  
Monica C. Chen ◽  
Travis E. Solomon ◽  
Eduardo Perez Salazar ◽  
Robert Kui ◽  
Enrique Rozengurt ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Tyrosine Phosphorylation ◽  
Molecular Mechanisms ◽  
Kinase Inhibitor ◽  
Paracellular Permeability ◽  
Maximal Response ◽  
Src Tyrosine Kinase

Previous studies found that epidermal growth factor (EGF) decreased paracellular permeability in gastric mucosa, but the other physiological regulators and the molecular mechanisms mediating these responses remain undefined. We investigated the role of secretin and Src in regulating paracellular permeability because secretin regulates gastric chief cell function and Src mediates events involving the cytoskeletal-membrane interface, respectively. Confluent monolayers were formed from canine gastric epithelial cells in short-term culture on Transwell filter inserts. Resistance was monitored in the presence of secretin with or without specific kinase inhibitors. Tyrosine phosphorylation of Src at Tyr416 was measured with a site-specific phosphotyrosine antibody. Basolateral, but not apical, secretin at concentrations from 1 to 100 nM dose dependently increased resistance; this response was rapid and sustained over hours. PP2 (10 μM), a selective Src tyrosine kinase inhibitor, but not the inactive isomer PP3, abolished the increase in resistance by secretin but only modestly attenuated apical EGF effects. AG-1478 (100 nM), a specific EGF receptor tyrosine kinase inhibitor, attenuated the resistance increase to EGF but not secretin. Secretin, but not EGF, induced tyrosine phosphorylation of Src at Tyr416 in a dose-dependent fashion, with the maximal response observed at 1 min. PP2, but not PP3, dramatically inhibited this tyrosine phosphorylation. Secretin increases paracellular resistance in gastric mucosa through a Src-mediated pathway, while the effect of EGF is Src independent. Src appears to mediate the physiological effects of this Gs-coupled receptor in primary epithelial cells.

scholarly journals Ionizing radiation induces epithelial–mesenchymal transition in human bronchial epithelial cells

2020 ◽  
Vol 40 (8) ◽  
Author(s):  
Bo Tang ◽  
Yue Xi ◽  
Fengmei Cui ◽  
Jin Gao ◽  
Huiqin Chen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Ionizing Radiation ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Bronchial Epithelial Cells ◽  
Human Bronchial Epithelial Cells ◽  
Migration Ability ◽  
Bronchial Epithelial ◽  
Mesenchymal Transition ◽  
Potential Biomarker

Abstract Objective: The present study aimed to analyze the mechanism by which long-term occupational exposure of workers to low-dose ionizing irradiation induces epithelial–mesenchymal transition (EMT) of the human bronchial epithelial cells using transcriptome profiling. Methods: RNA-seq transcriptomics was used to determine gene expression in blood samples from radiation-exposed workers followed by bioinformatics analysis. Normal bronchial epithelial cells (16HBE) were irradiated for different durations and subjected to immunofluorescence, Western blotting, scratch healing, and adhesion assays to detect the progression of EMT and its underlying molecular mechanisms. Results: Transcriptomics revealed that exposure to ionizing radiation led to changes in the expression of genes related to EMT, immune response, and migration. At increased cumulative doses, ionizing radiation-induced significant EMT, as evidenced by a gradual decrease in the expression of E-cadherin, increased vimentin, elevated migration ability, and decreased adhesion capability of 16HBE cells. The expression of fibronectin 1 (FN1) showed a gradual increase with the progression of EMT, and may be involved in EMT. Conclusion: Ionizing radiation induces EMT. FN1 may be involved in the progression of EMT and could serve as a potential biomarker for this process.

scholarly journals Let-7c-3p Regulates Autophagy under Oxidative Stress by Targeting ATG3 in Lens Epithelial Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Ting Li ◽  
Yanhong Huang ◽  
Wenkai Zhou ◽  
Qichang Yan
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Western Blot ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Age Related ◽  
Spot Number ◽  
Gene Assay

Background. Oxidative stress is an important factor during age-related cataract formation. Apoptosis and autophagy induced by oxidative stress have been reported as key factors in age-related cataract. In our research, we investigated the role of let-7c-3p in the regulation of autophagy and apoptosis during the formation of age-related cataract. Material and Methods. Real-time PCR and western blot were employed to detect the expression of let-7c-3p in the tissues of age-related cataract. Human lens epithelial cells (LECs) were treated with H2O2 as an age-related cataract model. The extent of apoptosis was measured by flow cytometry and western blot. To detect autophagy, immunofluorescence was used to analyze the spot number of LC3, and western blot was used to detect the expression of LC3-II/I and ATG3. The molecular mechanisms of let-7c-3p regulating autophagy via ATG3 under oxidative stress were performed by a luciferase report gene assay and rescue experiment. Results. Downregulation of let-7c-3p was found in the age-related cataract group aged >65 years relative to the age-related cataract group aged ≤65 years. Consistently, the expression of let-7c-3p was also lower under oxidative stress. The activities of LEC apoptosis and autophagy induced by oxidative stress were inhibited by let-7c-3p. By the bioinformatics database and the luciferase reporter assay, ATG3 was found to be a direct target of let-7c-3p. Let-7c-3p reduced the ATG3-mediated autophagy level, which was induced by oxidative stress in LECs. Conclusion. Let-7c-3p inhibits autophagy by targeting ATG3 in LECs in age-related cataract.

scholarly journals Dose-dependent effects of ketoprofen on the human gastric mucosa in comparison with ibuprofen

2000 ◽  
Vol 14 (5) ◽  
pp. 543-549 ◽  
Author(s):  
Donnelly ◽  
Richardson ◽  
Hawkey ◽  
Courtauld ◽  
Stack
Keyword(s):  
Gastric Mucosa ◽  
Human Gastric Mucosa ◽  
Dose Dependent

scholarly journals Interference with NTSR1 Expression Exerts an Anti-Invasion Effect via the Jun/miR-494/SOCS6 Axis of Glioblastoma Cells

2018 ◽  
Vol 49 (6) ◽  
pp. 2382-2395 ◽  
Author(s):  
Qing Ou-yang ◽  
Xuzhi He ◽  
Anqi Yang ◽  
Bing Li ◽  
Minhui Xu
Keyword(s):  
Western Blotting ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Cytokine Signaling ◽  
Glioblastoma Cells ◽  
Suppressor Of Cytokine Signaling ◽  
Underlying Mechanisms ◽  
Neurotensin Receptor 1

Background/Aims: Glioblastoma is the most common and aggressive brain tumor and carries a poor prognosis. Previously, we found that neurotensin receptor 1 (NTSR1) contributes to glioma progression, but the underlying mechanisms of NTSR1 in glioblastoma invasion remain to be clarified. The aim of this study was to investigate the molecular mechanisms of NTSR1 in glioblastoma invasion. Methods: Cell migration and invasion were evaluated using wound-healing and transwell assays. Cell proliferation was detected using CCK-8. The expression of NTSR1, Jun, and suppressor of cytokine signaling 6 (SOCS6) was detected using western blotting. The expression of miR-494 was detected by Quantitative real-time PCR. Chromatin immunoprecipitation assay was performed to examine the interaction between Jun and miR-494 promoter. Dual-luciferase reporter assay and western blotting were performed to identify the direct regulation of SOCS6 by miR-494. An orthotopic xenograft mouse model was conducted to assess tumor growth and invasion. Results: NTSR1 knockdown attenuated the invasion of glioblastoma cells. Jun was positively regulated by NTSR1, which promoted miR-494 expression through binding to miR-494 promoter. SOCS6 was confirmed as a direct target of miR-494, thus, NTSR1-induced miR-494 upregulation resulted in SOCS6 downregulation. Both miR-494 and SOCS6 were involved in the NTSR1-induced invasion of glioblastoma cells. In vivo, tumor invasion and growth were inhibited by NTSR1 knockdown, but were restored with miR-494 overexpression. Conclusion: NTSR1 knockdown inhibited glioblastoma invasion via the Jun/miR-494/SOCS6 axis.

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