Interferon-γ induces C/EBPβ expression and activity through MEK/ERK and p38 in T84 colon epithelial cells

2003 ◽  
Vol 284 (5) ◽  
pp. C1133-C1139 ◽  
Author(s):  
Pertteli Salmenperä ◽  
Sammy Hämäläinen ◽  
Mika Hukkanen ◽  
Esko Kankuri
Keyword(s):  
Epithelial Cells ◽  
Kinase Inhibitor ◽  
Interferon Γ ◽  
Epithelial Cell Line ◽  
P38 Inhibitor ◽  
Enhancer Binding Protein ◽  
Ifn Γ ◽  
Colon Epithelial Cell ◽  
Expression And Activity

We investigated the role of IFN-γ and MAPKs on the expression and activity of the transcription factor CCAAT/enhancer-binding protein-beta (C/EBPβ) in the T84 colon epithelial cell line. IFN-γ induced the expression and activity of C/EBPβ and subsequently increased the secretion of IL-6 from these cells. Treatment with the p38 inhibitor SB-203580, the MEK1 and MEK2 inhibitor U-0126, or the translational inhibitor cycloheximide inhibited the induction of C/EBPβ and IL-6 by IFN-γ, whereas the MEK1 inhibitor PD-98059 or the tyrosine kinase inhibitor genistein had no effect. These results suggest a role for MEK2 and p38 in IFN-γ-mediated signal transduction and induction of C/EBPβ expression and activity associated with interleukin-6 (IL-6) secretion in colon epithelial cells.

scholarly journals Expression of the retinoblastoma protein RbAp48 in exocrine glands leads to Sjögren's syndrome–like autoimmune exocrinopathy

2008 ◽  
Vol 205 (12) ◽  
pp. 2915-2927 ◽  
Author(s):  
Naozumi Ishimaru ◽  
Rieko Arakaki ◽  
Satoko Yoshida ◽  
Akiko Yamada ◽  
Sumihare Noji ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Interferon Γ ◽  
Estrogen Deficiency ◽  
Exocrine Glands ◽  
Class Ii Transactivator ◽  
Local Tolerance ◽  
Ifn Γ ◽  
Gender Based ◽  
Autoimmune Exocrinopathy

Although several autoimmune diseases are known to develop in postmenopausal women, the mechanisms by which estrogen deficiency influences autoimmunity remain unclear. Recently, we found that retinoblastoma-associated protein 48 (RbAp48) induces tissue-specific apoptosis in the exocrine glands depending on the level of estrogen deficiency. In this study, we report that transgenic (Tg) expression of RbAp48 resulted in the development of autoimmune exocrinopathy resembling Sjögren's syndrome. CD4+ T cell–mediated autoimmune lesions were aggravated with age, in association with autoantibody productions. Surprisingly, we obtained evidence that salivary and lacrimal epithelial cells can produce interferon-γ (IFN-γ) in addition to interleukin-18, which activates IFN regulatory factor-1 and class II transactivator. Indeed, autoimmune lesions in Rag2−/− mice were induced by the adoptive transfer of lymph node T cells from RbAp48-Tg mice. These results indicate a novel immunocompetent role of epithelial cells that can produce IFN-γ, resulting in loss of local tolerance before developing gender-based autoimmunity.

scholarly journals The Role of Interleukine-10 and Interferon-γ as Potential Markers of the Evolution of African Swine Fever Virus Infection in Wild Boar

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 757
Author(s):  
Sandra Barroso-Arévalo ◽  
Jose A. Barasona ◽  
Estefanía Cadenas-Fernández ◽  
José M. Sánchez-Vizcaíno
Keyword(s):  
Wild Boar ◽  
Vaccine Candidate ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Interferon Γ ◽  
Fever Virus ◽  
Control Group ◽  
Challenge Virus ◽  
Ifn Γ

African swine fever virus (ASFv) is one of the most challenging pathogens to affect both domestic and wild pigs. The disease has now spread to Europe and Asia, causing great damage to the pig industry. Although no commercial vaccine with which to control the disease is, as yet, available, some potential vaccine candidates have shown good results in terms of protection. However, little is known about the host immune mechanisms underlying that protection, especially in wild boar, which is the main reservoir of the disease in Europe. Here, we study the role played by two cytokines (IL-10 and IFN-γ) in wild boar orally inoculated with the attenuated vaccine candidate Lv17/WB/Rie1 and challenged with a virulent ASFv genotype II isolate. A group of naïve wild boar challenged with the latter isolate was also established as a control group. Our results showed that both cytokines play a key role in protecting the host against the challenge virus. While high levels of IL-10 in serum may trigger an immune system malfunctioning in challenged animals, the provision of stable levels of this cytokine over time may help to control the disease. This, together with high and timely induction of IFN-γ by the vaccine candidate, could help protect animals from fatal outcomes. Further studies should be conducted in order to support these preliminary results and confirm the role of these two cytokines as potential markers of the evolution of ASFV infection.

Protein synthesis-dependent potentiation by thyroxine of antiviral activity of interferon-γ

1997 ◽  
Vol 273 (4) ◽  
pp. C1225-C1232 ◽  
Author(s):  
Hung-Yun Lin ◽  
Paul M. Yen ◽  
Faith B. Davis ◽  
Paul J. Davis
Keyword(s):  
Thyroid Hormone ◽  
Antiviral Activity ◽  
Tyrosine Kinase ◽  
Kinase Inhibitor ◽  
Thyroid Hormone Receptor ◽  
Signal Transduction Pathway ◽  
Interferon Γ ◽  
Human Interferon ◽  
Transduction Pathway ◽  
Ifn Γ

We have studied the prenuclear signal transduction pathway by which thyroid hormone potentiates the antiviral activity of human interferon-γ (IFN-γ) in HeLa cells, which are deficient in thyroid hormone receptor (TR). The action of thyroid hormone was compared with that of milrinone, which has structural homologies with thyroid hormone.l-Thyroxine (T4), 3,5,3′-l-triiodothyronine (T3), and milrinone enhanced the antiviral activity of IFN-γ up to 100-fold, a potentiation blocked by cycloheximide. The 5′-deiodinase inhibitor 6- n-propyl-2-thiouracil did not block the T4 effect. 3,3′,5,5′-Tetraiodothyroacetic acid prevented the effect of T4 but not of milrinone. The effects of T4 and milrinone were blocked by inhibitors of protein kinases C (PKC) and A (PKA) and restored by PKC and PKA agonists; only the effect of T4 was blocked by genistein, a tyrosine kinase inhibitor. In separate models, milrinone was shown not to interact with nuclear TR-β. T4 potentiation of the antiviral activity of IFN-γ requires PKC, PKA, and tyrosine kinase activities but not traditional TR.

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

2020 ◽  
Vol 318 (4) ◽  
pp. C732-C739
Author(s):  
Fangyi Liu ◽  
Xiao Wang ◽  
Hua Geng ◽  
Heng-Fu Bu ◽  
Peng Wang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Protein Expression ◽  
Intestinal Epithelial Cells ◽  
Specific Inhibitor ◽  
In Silico Analysis ◽  
Interferon Γ ◽  
Luciferase Assay ◽  
Epithelial Cell Line ◽  
Dependent Manner ◽  
Intestinal Epithelial

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.

scholarly journals Role of Gamma Interferon in Helicobacter pylori Induction of Inflammatory Mediators during Murine Infection

2002 ◽  
Vol 70 (6) ◽  
pp. 3295-3299 ◽  
Author(s):  
Marygorret Obonyo ◽  
Donald G. Guiney ◽  
Julia Harwood ◽  
Joshua Fierer ◽  
Sheri P. Cole
Keyword(s):  
Helicobacter Pylori ◽  
Gene Knockout ◽  
Gamma Interferon ◽  
Epithelial Cell Line ◽  
Inos Mrna ◽  
Inflammatory Protein ◽  
Ifn Γ ◽  
H Pylori ◽  
Oxide Synthase

ABSTRACT Gamma interferon (IFN-γ) has been proposed to play an important role in Helicobacter-related gastritis. Using the IFN-γ gene knockout (IFN-γ−/−) mouse model and a murine gastric epithelial cell line, GSM06, we demonstrated that Helicobacter pylori maximally induced macrophage inflammatory protein-2 (MIP-2) and inducible nitric oxide synthase (iNOS) mRNA only in wild-type mice. MIP-2 and iNOS mRNA were also induced by H. pylori in GSM06 cells. Induction of cyclooxygenase 2 mRNA through IFN-γ was demonstrated in GSM06 cells. These data indicate that IFN-γ mediates the induction of MIP-2 and iNOS mRNA expression by H. pylori in mice.

scholarly journals Toll-like Receptor 4 Resides in the Golgi Apparatus and Colocalizes with Internalized Lipopolysaccharide in Intestinal Epithelial Cells

2002 ◽  
Vol 195 (5) ◽  
pp. 559-570 ◽  
Author(s):  
Mathias W. Hornef ◽  
Teresa Frisan ◽  
Alain Vandewalle ◽  
Staffan Normark ◽  
Agneta Richter-Dahlfors
Keyword(s):  
Epithelial Cells ◽  
Golgi Apparatus ◽  
Intestinal Epithelial Cells ◽  
Surface Membrane ◽  
Epithelial Cell Line ◽  
Continuous Exposure ◽  
Immune Recognition ◽  
Intestinal Epithelial ◽  
Toll Like Receptor

Toll-like receptor (TLR) 4 is mainly found on cells of the myelopoietic lineage. It recognizes lipopolysaccharide (LPS) and mediates cellular activation and production of proinflammatory cytokines. Less is known about the distribution and role of TLR4 in epithelial cells that are continuously exposed to microbes and microbial products. Here we show that the murine small intestinal epithelial cell line m-ICcl2 is highly responsive to LPS and expresses both CD14 and TLR4. Transcription and surface membrane staining for CD14 were up-regulated upon LPS exposure. Surprisingly, TLR4 immunostaining revealed a strictly cytoplasmic paranuclear distribution. This paranuclear compartment could be identified as the Golgi apparatus. LPS added to the supernatant was internalized by m-ICcl2 cells and colocalized with TLR4. Continuous exposure to LPS led to a tolerant phenotype but did not alter TLR4 expression nor cellular distribution. Thus, intestinal epithelial cells might be able to provide the initial proinflammatory signal to attract professional immune cells to the side of infection. The cytoplasmic location of TLR4, which is identical to the final location of internalized LPS, further indicates an important role of cellular internalization and cytoplasmic traffic in the process of innate immune recognition.

scholarly journals Distinctive role of Stat3 and Erk-1/2 activation in mediating interferon-γ inhibition of TGF-β1 action

2006 ◽  
Vol 290 (5) ◽  
pp. F1234-F1240 ◽  
Author(s):  
Myrto Giannopoulou ◽  
Steven C. Iszkula ◽  
Chunsun Dai ◽  
Xiaoyue Tan ◽  
Junwei Yang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Ectopic Expression ◽  
Interferon Γ ◽  
Signal Pathways ◽  
Tubular Epithelial Cells ◽  
Plasminogen Activator Inhibitor 1 ◽  
Ifn Γ ◽  
Pai 1

Interferon-γ (IFN-γ) is a multifunctional cytokine that elicits antifibrotic activity in a variety of organs. In this study, we investigated the potential role and mechanism of IFN-γ in modulating the fibrogenic action of transforming growth factor (TGF)-β1 in tubular epithelial cells. Incubation of human proximal tubular epithelial (HKC) cells with IFN-γ inhibited TGF-β1-mediated α-smooth muscle actin (α-SMA) expression. IFN-γ also abolished TGF-β1-induced fibronectin and plasminogen activator inhibitor-1 (PAI-1) expression. To explore the mechanisms by which INF-γ inhibits TGF-β1 action, the signaling pathways that are critical for mediating the antifibrotic activity of IFN-γ were studied. Stimulation of HKC cells with IFN-γ triggered a sustained activation of Erk-1/2 and signal transducer and activator of transcription-3 (Stat3). Blockade of Erk-1/2 activation with an Mek1 inhibitor abolished the inhibitory effect of IFN-γ on α-SMA expression, whereas inhibition of Stat3 activation had no influence. Constitutive activation of Erk-1/2 by ectopic expression of activated Mek1 mimicked IFN-γ and suppressed TGF-β1-mediated α-SMA expression. Interestingly, inhibition of Stat3 activation abolished the ability of IFN-γ to attenuate TGF-β1-mediated PAI-1 and fibronectin expression in HKC cells. These findings indicate that IFN-γ is capable of antagonizing the fibrogenic actions of TGF-β1 in renal tubular epithelial cells. The antifibrotic action of IFN-γ appears to be mediated through a coordinated activation of both Erk-1/2 and Stat3 signal pathways in a mutually independent fashion.

scholarly journals Cross-Talk between Adherens Junctions and Desmosomes Depends on Plakoglobin

1997 ◽  
Vol 136 (4) ◽  
pp. 919-934 ◽  
Author(s):  
Jani E. Lewis ◽  
James K. Wahl ◽  
Kristin M. Sass ◽  
Pamela J. Jensen ◽  
Keith R. Johnson ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Line ◽  
Adherens Junctions ◽  
Adherens Junction ◽  
Epithelial Cell Line ◽  
Cell Contact ◽  
Common Component ◽  
Classical Cadherins ◽  
E Cadherin

Squamous epithelial cells have both adherens junctions and desmosomes. The ability of these cells to organize the desmosomal proteins into a functional structure depends upon their ability first to organize an adherens junction. Since the adherens junction and the desmosome are separate structures with different molecular make up, it is not immediately obvious why formation of an adherens junction is a prerequisite for the formation of a desmosome. The adherens junction is composed of a transmembrane classical cadherin (E-cadherin and/or P-cadherin in squamous epithelial cells) linked to either β-catenin or plakoglobin, which is linked to α-catenin, which is linked to the actin cytoskeleton. The desmosome is composed of transmembrane proteins of the broad cadherin family (desmogleins and desmocollins) that are linked to the intermediate filament cytoskeleton, presumably through plakoglobin and desmoplakin. To begin to study the role of adherens junctions in the assembly of desmosomes, we produced an epithelial cell line that does not express classical cadherins and hence is unable to organize desmosomes, even though it retains the requisite desmosomal components. Transfection of E-cadherin and/or P-cadherin into this cell line did not restore the ability to organize desmosomes; however, overexpression of plakoglobin, along with E-cadherin, did permit desmosome organization. These data suggest that plakoglobin, which is the only known common component to both adherens junctions and desmosomes, must be linked to E-cadherin in the adherens junction before the cell can begin to assemble desmosomal components at regions of cell–cell contact. Although adherens junctions can form in the absence of plakoglobin, making use only of β-catenin, such junctions cannot support the formation of desmosomes. Thus, we speculate that plakoglobin plays a signaling role in desmosome organization.

Superantigen immune stimulation activates epithelial STAT-1 and PI 3-K: PI 3-K regulation of permeability

2000 ◽  
Vol 279 (5) ◽  
pp. G1094-G1103 ◽  
Author(s):  
Derek M. McKay ◽  
Fernando Botelho ◽  
Peter J. M. Ceponis ◽  
Carl D. Richards
Keyword(s):  
Epithelial Cells ◽  
Conditioned Medium ◽  
Intracellular Signaling ◽  
Mononuclear Cells ◽  
Interferon Γ ◽  
Transepithelial Resistance ◽  
Mobility Shift ◽  
Peripheral Blood Mononuclear ◽  
Ussing Chambers ◽  
Ifn Γ

Signal transducers and activators of transcription (STATs) are critical intracellular signaling molecules for many cytokines. We compared the ability of T84 epithelial cells to activate STATs in response to cytokines [interferon-γ (IFN-γ), interleukin (IL)-4, IL-10, and tumor necrosis factor-α (10 ng/ml)] and conditioned medium from superantigen [ Staphylococcus aureus enterotoxin B (SEB)]-activated peripheral blood mononuclear cells (PBMC) using electrophoretic mobility shift assays (EMSA). Of the cytokines tested, only IFN-γ caused a STAT-1 response. Exposure to SEB-PBMC-conditioned medium resulted in STAT-1 or STAT-1/3 activation, and inclusion of anti-IFN-γ antibodies in the conditioned medium abolished the STAT-1 signal. Cells treated with transcription factor decoys, DNA oligonucleotides bearing the STAT-1 recognition motif, and then SEB-PBMC-conditioned medium displayed a reduced STAT-1 signal on EMSA, yet this treatment did not prevent the drop in transepithelial resistance (measured in Ussing chambers) caused by SEB-PBMC-conditioned medium. In contrast, the phosphatidylinositol 3′-kinase (PI 3-K) inhibitor LY-294002 significantly reduced the drop in transepithelial resistance caused by SEB-PBMC-conditioned medium. Thus data are presented showing STAT-1 (±STAT-3) and PI 3-K activation in epithelial cells in response to immune mediators released by superantigen immune activation. Although the involvement of STAT-1/-3 in the control of barrier function remains a possibility, PI-3K has been identified as a regulator of T84 paracellular permeability.

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