Interferon-γ inhibits sirtuin 6 gene expression in intestinal epithelial cells through a microRNA-92b-dependent mechanism

Sirtuin 6 (Sirt6) is predominantly expressed in epithelial cells in intestinal crypts. It plays an important role in protecting intestinal epithelial cells against inflammatory injury. Previously, we found that colitis is associated with the downregulation of Sirt6 protein in the intestines. Here, we report that murine interferon-γ (Ifnγ) inhibits Sirt6 protein but not mRNA expression in young adult mouse colonocytes (YAMC, a mouse colonic epithelial cell line) in a dose- and time-dependent manner. Using microRNA array analysis, we showed that Ifnγ induces expression of miR-92b in YAMC cells. With in silico analysis, we found that the Sirt6 3′-untranslated region (UTR) contains a putative binding site for miR-92b. Luciferase assay showed that Ifnγ inhibited Sirt6 3′-UTR activity and this effect was mimicked by miR-92b via directly targeting the miR-92b seed site in the 3′-UTR of Sirt6 mRNA. Furthermore, Western blot demonstrated that miR-92b downregulated Sirt6 protein expression in YAMC cells. Blocking miR-92b with a specific inhibitor attenuated the inhibitory effect of Ifnγ on Sirt6 protein expression in the cells. Collectively, our data suggest that Ifnγ inhibits Sirt6 protein expression in intestinal epithelial cells via a miR-92b-mediated mechanism. miR-92b may be a novel therapeutic target for rescuing Sirt6 protein levels in intestinal epithelial cells, thereby protecting against intestinal mucosal injury caused by inflammation.

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Bacillus subtilis and surfactin inhibit the transmissible gastroenteritis virus from entering the intestinal epithelial cells

Bioscience Reports ◽

10.1042/bsr20170082 ◽

2017 ◽

Vol 37 (2) ◽

Cited By ~ 14

Author(s):

Xiaoqing Wang ◽

Weiwei Hu ◽

Liqi Zhu ◽

Qian Yang

Keyword(s):

Bacillus Subtilis ◽

Epithelial Cells ◽

Plant Pathogens ◽

Intestinal Epithelial Cells ◽

Host Cells ◽

Transmissible Gastroenteritis Virus ◽

Epithelial Cell Line ◽

Dependent Manner ◽

Intestinal Epithelial ◽

Transmissible Gastroenteritis

Intestinal epithelial cells are the targets for transmissible gastroenteritis (TGE) virus (TGEV) infection. It is urgent to develop a novel candidate against TGEV entry. Bacillus subtilis is a probiotic with excellent anti-microorganism properties and one of its secretions, surfactin, has been regarded as a versatile weapon for most plant pathogens, especially for the enveloped virus. We demonstrate for the first time that B. subtilis OKB105 and its surfactin can effectively inhibit one animal coronavirus, TGEV, entering the intestinal porcine epithelial cell line (IPEC-J2). Then, several different experiments were performed to seek the might mechanisms. The plaque assays showed that surfactant could reduce the plaque generation of TGEV in a dose-dependent manner. Meanwhile, after incubation with TGEV for 1.5 h, B. subtilis could attach TGEV particles to their surface so that the number of virus to bind to the host cells was declined. Furthermore, our data showed that the inhibition of B. subtilis was closely related to the competition with TGEV for the viral entry receptors, including epidermal growth factor receptor (EGFR) and aminopeptidase N (APN) protein. In addition, Western blotting and apoptosis analysis indicated that B. subtilis could enhance the resistance of IPEC-J2 cells by up-regulating the expression of toll-like receptor (TLR)-6 and reducing the percentage of apoptotic cells. Taken together, our results suggest that B. subtilis OKB105 and its surfactin can antagonize TGEV entry in vitro and may serve as promising new candidates for TGEV prevention.

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PKCδ-dependent activation of ERK1/2 leads to upregulation of the human NHE2 transcriptional activity in intestinal epithelial cell line C2BBe1

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00363.2011 ◽

2012 ◽

Vol 302 (3) ◽

pp. G317-G325 ◽

Cited By ~ 9

Author(s):

Saminathan Muthusamy ◽

Sagar Shukla ◽

Md. Ruhul Amin ◽

Ming Cheng ◽

Temitope Orenuga ◽

...

Keyword(s):

Transcription Factor ◽

Epithelial Cells ◽

Signaling Pathways ◽

Intestinal Epithelial Cells ◽

Specific Inhibitor ◽

Epithelial Cell Line ◽

Intestinal Epithelial ◽

Nuclear Extracts ◽

Mitogen Activated Protein ◽

Stimulation Of

The apical Na+/H+ exchanger (NHE) isoform NHE2 is involved in transepithelial Na+ absorption in the intestine. Our earlier studies have shown that mitogenic agent phorbol 12-myristate 13-acetate (PMA) induces the expression of NHE2 through activation of transcription factor early growth response-1 (Egr-1) and its interactions with the NHE2 promoter. However, the signaling pathways involved in transcriptional stimulation of NHE2 in response to PMA in the intestinal epithelial cells are not known. Chemical inhibitors and genetic approaches were used to investigate the signaling pathways responsible for the stimulation of NHE2 expression by PMA via Egr-1 induction. We show that, in response to PMA, PKCδ, a member of novel PKC isozymes, and MEK-ERK1/2 pathway of mitogen-activated protein kinases stimulate the NHE2 expression in C2BBe1 intestinal epithelial cells. PMA rapidly and transiently induced activation of PKCδ. Small inhibitory RNA-mediated knockdown of PKCδ blocked the stimulatory effect of PMA on the NHE2 promoter activity. In addition, blockade of PKCδ by rottlerin, a PKCδ-specific inhibitor, and ERK1/2 by U0126, a MEK-ERK inhibitor, abrogated PMA-induced Egr-1 expression. Immunofluorescence studies revealed that inhibition of ERK1/2 activation prevents translocation of PMA-induced Egr-1 into the nucleus. Consistent with these data, PMA-induced Egr-1 interaction with the NHE2 promoter region was prevented in nuclear extracts from U0126-pretreated cells. In conclusion, our data provide the first evidence that the stimulatory effect of PMA on NHE2 expression is mediated through the initial activation of PKCδ, subsequent PKCδ-dependent activation of MEK-ERK1/2 signaling pathway, and stimulation of Egr-1 expression. Furthermore, we show that transcription factor Egr-1 acts as an intermediate effector molecule that links the upstream signaling cues to the long-term stimulation of NHE2 expression by PMA in C2BBe1 cells.

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Interferon-γ Augments CARD4/NOD1 Gene and Protein Expression through Interferon Regulatory Factor-1 in Intestinal Epithelial Cells

Journal of Biological Chemistry ◽

10.1074/jbc.m304355200 ◽

2003 ◽

Vol 278 (35) ◽

pp. 32962-32968 ◽

Cited By ~ 73

Author(s):

Tadakazu Hisamatsu ◽

Manabu Suzuki ◽

Daniel K. Podolsky

Keyword(s):

Epithelial Cells ◽

Protein Expression ◽

Intestinal Epithelial Cells ◽

Interferon Γ ◽

Interferon Regulatory Factor ◽

Intestinal Epithelial ◽

Regulatory Factor ◽

Interferon Regulatory Factor 1 ◽

Gene And Protein Expression

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Positive cross talk between protein kinase D and β-catenin in intestinal epithelial cells: impact on β-catenin nuclear localization and phosphorylation at Ser552

AJP Cell Physiology ◽

10.1152/ajpcell.00302.2015 ◽

2016 ◽

Vol 310 (7) ◽

pp. C542-C557 ◽

Cited By ~ 9

Author(s):

Jia Wang ◽

Liang Han ◽

James Sinnett-Smith ◽

Li-Li Han ◽

Jan V. Stevens ◽

...

Keyword(s):

Protein Kinase ◽

Epithelial Cells ◽

Transgenic Mice ◽

Nuclear Localization ◽

Cross Talk ◽

Intestinal Epithelial Cells ◽

Dependent Manner ◽

Intestinal Epithelial ◽

Ang Ii ◽

Potent Inducer

Given the fundamental role of β-catenin signaling in intestinal epithelial cell proliferation and the growth-promoting function of protein kinase D1 (PKD1) in these cells, we hypothesized that PKDs mediate cross talk with β-catenin signaling. The results presented here provide several lines of evidence supporting this hypothesis. We found that stimulation of intestinal epithelial IEC-18 cells with the G protein-coupled receptor (GPCR) agonist angiotensin II (ANG II), a potent inducer of PKD activation, promoted endogenous β-catenin nuclear localization in a time-dependent manner. A significant increase was evident within 1 h of ANG II stimulation ( P < 0.01), peaked at 4 h ( P < 0.001), and declined afterwards. GPCR stimulation also induced a marked increase in β-catenin-regulated genes and phosphorylation at Ser552 in intestinal epithelial cells. Exposure to preferential inhibitors of the PKD family (CRT006610 or kb NB 142-70) or knockdown of the isoforms of the PKD family prevented the increase in β-catenin nuclear localization and phosphorylation at Ser552 in response to ANG II. GPCR stimulation also induced the formation of a complex between PKD1 and β-catenin, as shown by coimmunoprecipitation that depended on PKD1 catalytic activation, as it was abrogated by cell treatment with PKD family inhibitors. Using transgenic mice that express elevated PKD1 protein in the intestinal epithelium, we detected a marked increase in the localization of β-catenin in the nucleus of crypt epithelial cells in the ileum of PKD1 transgenic mice, compared with nontransgenic littermates. Collectively, our results identify a novel cross talk between PKD and β-catenin in intestinal epithelial cells, both in vitro and in vivo.

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Sa1729 ER Stress Leads to Epithelial to Mesenchymal Transition (EMT) in Intestinal Epithelial Cells in a JNK-and SRC-Dependent Manner

Gastroenterology ◽

10.1016/s0016-5085(14)61000-3 ◽

2014 ◽

Vol 146 (5) ◽

pp. S-283

Author(s):

Claudia Stanzel ◽

Anne Terhalle ◽

Michael Scharl ◽

Gerhard Rogler

Keyword(s):

Epithelial Cells ◽

Er Stress ◽

Epithelial To Mesenchymal Transition ◽

Intestinal Epithelial Cells ◽

Dependent Manner ◽

Intestinal Epithelial ◽

Mesenchymal Transition

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Glutamine protects intestinal epithelial cells: role of inducible HSP70

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1997.272.4.g879 ◽

1997 ◽

Vol 272 (4) ◽

pp. G879-G884 ◽

Cited By ~ 38

Author(s):

P. E. Wischmeyer ◽

M. W. Musch ◽

M. B. Madonna ◽

R. Thisted ◽

E. B. Chang

Keyword(s):

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Mucosal Healing ◽

Epithelial Cell Line ◽

Protective Effects ◽

Intestinal Epithelial ◽

Cellular Protection ◽

Gut Mucosa ◽

Shock Proteins ◽

Hsp70 Induction

Glutamine (Gln) protects gut mucosa against injury and promotes mucosal healing. Because the induction of heat shock proteins (HSP) protects cells under conditions of stress, we determined whether Gln conferred protection against stress in an intestinal epithelial cell line through HSP induction. Gln added to IEC-18 cells induces an increase in HSP70, a concentration-dependent effect also seen with mRNA. Two forms of injury, lethal heat (49 degrees C) and oxidant, were used, and viability was determined by 51Cr release. Gln-treated cells were significantly more resistant to injury. Treatment with 6-diazo-5-oxo-L-norleucine (DON), a nonmetabolizable analog of Gln, induced HSP70 and protected cells from injury, but less than Gln. These findings suggest that the effects of Gln on HSP70 induction and cellular protection are mediated by metabolic and nonmetabolic mechanisms. To determine whether HSP induction was central to the action of Gln and DON, quercetin, which blocks HSP induction, was used. Quercetin blocked HSP70 induction and the protective effect of Gln and DON. We conclude that the protective effects of Gln in intestinal epithelial cells are in part mediated by HSP70 induction.

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Co-operation of interleukin-17 and interferon-γ on chemokine secretion in human fetal intestinal epithelial cells

Gastroenterology ◽

10.1016/s0016-5085(08)80938-9 ◽

2001 ◽

Vol 120 (5) ◽

pp. A189

Author(s):

Hiroki Takaya ◽

Akira Andoh ◽

Jin Makino ◽

Takashi Okuno ◽

Kazunori Hata ◽

...

Keyword(s):

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Interferon Γ ◽

Interleukin 17 ◽

Intestinal Epithelial

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Lipid rafts mediate internalization of β1-integrin in migrating intestinal epithelial cells

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00082.2008 ◽

2008 ◽

Vol 295 (5) ◽

pp. G965-G976 ◽

Cited By ~ 44

Author(s):

Elena V. Vassilieva ◽

Kirsten Gerner-Smidt ◽

Andrei I. Ivanov ◽

Asma Nusrat

Keyword(s):

Epithelial Cells ◽

Lipid Rafts ◽

Lipid Raft ◽

Intestinal Epithelial Cells ◽

Focal Adhesions ◽

Endocytic Pathway ◽

Dependent Manner ◽

Intestinal Epithelial ◽

Caveolin 1 ◽

Cell Matrix

Intestinal mucosal inflammation is associated with epithelial wounds that rapidly reseal by migration of intestinal epithelial cells (IECs). Cell migration involves cycles of cell-matrix adhesion/deadhesion that is mediated by dynamic turnover (assembly and disassembly) of integrin-based focal adhesions. Integrin endocytosis appears to be critical for deadhesion of motile cells. However, mechanisms of integrin internalization during remodeling of focal adhesions of migrating IECs are not understood. This study was designed to define the endocytic pathway that mediates internalization of β1-integrin in migrating model IECs. We observed that, in SK-CO15 and T84 colonic epithelial cells, β1-integrin is internalized in a dynamin-dependent manner. Pharmacological inhibition of clathrin-mediated endocytosis or macropinocytosis and small-interfering RNA (siRNA)-mediated knock down of clathrin did not prevent β1-integrin internalization. However, β1-integrin internalization was inhibited following cholesterol extraction and after overexpression of lipid raft protein, caveolin-1. Furthermore, internalized β1-integrin colocalized with the lipid rafts marker cholera toxin, and siRNA-mediated knockdown of caveolin-1 and flotillin-1/2 increased β1-integrin endocytosis. Our data suggest that, in migrating IEC, β1-integrin is internalized via a dynamin-dependent lipid raft-mediated pathway. Such endocytosis is likely to be important for disassembly of integrin-based cell-matrix adhesions and therefore in regulating IEC migration and wound closure.

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