scholarly journals miR-221 suppresses ICAM-1 translation and regulates interferon-γ-induced ICAM-1 expression in human cholangiocytes

2010 ◽  
Vol 298 (4) ◽  
pp. G542-G550 ◽  
Author(s):  
Guoku Hu ◽  
Ai-Yu Gong ◽  
Jun Liu ◽  
Rui Zhou ◽  
Caishu Deng ◽  
...  
Keyword(s):  
Protein Expression ◽  
Posttranscriptional Regulation ◽  
Untranslated Region ◽  
Inflammatory Responses ◽  
Target Prediction ◽  
Interferon Γ ◽  
Pathological Feature ◽  
Dependent Manner ◽  
Inflammatory Stimuli ◽  
Ifn Γ

Aberrant cholangiocyte reactions in response to inflammatory stimuli are important pathogenic factors for the persistent biliary inflammation in patients with cholangiopathies. Overexpression of intercellular cell adhesion molecule-1 (ICAM-1) in cholangiocytes is a common pathological feature in inflammatory cholangiopathies and can promote cholangiocyte interactions with effector lymphocytes in the portal region. In this study, we tested the involvement of miRNA-mediated posttranscriptional regulation in IFN-γ-induced ICAM-1 expression in cholangiocytes. Using both immortalized and nonimmortalized human cholangiocyte cell lines, we found that IFN-γ activated ICAM-1 transcription and increased ICAM-1 protein expression. Inhibition of ICAM-1 transcription could only partially block IFN-γ-induced ICAM-1 expression at the protein level. In silico target prediction analysis revealed complementarity of miR-221 to the 3′-untranslated region of ICAM-1 mRNA. Targeting of ICAM-1 3′-untranslated region by miR-221 resulted in translational repression in cholangiocytes but not ICAM-1 mRNA degradation. Functional inhibition of miR-221 with anti-miR-221 induced ICAM-1 protein expression. Moreover, IFN-γ stimulation decreased miR-221 expression in cholangiocytes in a signal transducer and activator of transcription 1-dependent manner. Transfection of miR-221 precursor abolished IFN-γ-stimulated ICAM-1 protein expression. In addition, miR-221-mediated expression of ICAM-1 on cholangiocytes showed a significant influence on the adherence of cocultured T cells. These findings indicate that both transcriptional and miRNA-mediated posttranscriptional mechanisms are involved in IFN-γ-induced ICAM-1 expression in human cholangiocytes, suggesting an important role for miRNAs in the regulation of cholangiocyte inflammatory responses.

scholarly journals Continuing Effect of Cytokines and Toll-Like Receptor Agonists on Indoleamine-2,3-Dioxygenase-1 in Human Periodontal Ligament Stem/Stromal Cells

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2696
Author(s):  
Christian Behm ◽  
Alice Blufstein ◽  
Johannes Gahn ◽  
Barbara Kubin ◽  
Andreas Moritz ◽  
...  
Keyword(s):  
Protein Expression ◽  
Enzymatic Activity ◽  
Stromal Cells ◽  
Periodontal Ligament ◽  
Dependent Manner ◽  
Toll Like Receptor ◽  
Indoleamine 2,3 Dioxygenase ◽  
Tnf Α ◽  
Inflammatory Stimuli ◽  
Ifn Γ

Transplanted mesenchymal stem/stromal cells (MSCs) are a promising and innovative approach in regenerative medicine. Their regenerative potential is partly based upon their immunomodulatory activities. One of the most investigated immunomediators in MSCs, such as in periodontal ligament-derived MSCs (hPDLSCs), is indoleamine-2,3-dioxygenase-1 (IDO-1) which is upregulated by inflammatory stimuli, like cytokines. However, there are no data concerning continuing IDO-1 expression in hPDLSCs after the removal of inflammatory stimuli, such as cytokines and toll-like receptor (TLR) agonist-2 and TLR-3. Hence, primary hPDLSCs were stimulated with interleukin (IL)-1β, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, TLR-2 agonist Pam3CSK4 or TLR-3 agonist Poly I/C. IDO-1 gene and protein expression and its enzymatic activity were measured up to five days after removing any stimuli. IL-1β- and TNF-α-induced IDO-1 expression and enzymatic activity decreased in a time-dependent manner after cessation of stimulation. IFN-γ caused a long-lasting effect on IDO-1 up to five days after removing IFN-γ. Both, TLR-2 and TLR-3 agonists induced a significant increase in IDO-1 gene expression, but only TLR-3 agonist induced significantly higher IDO-1 protein expression and enzymatic activity in conditioned media (CM). IDO-1 activity of Poly I/C- and Pam3CSK4-treated hPDLSCs was higher at one day after removal of stimuli than immediately after stimulation and declined to basal levels after five days. Among all tested stimuli, only IFN-γ was able to induce long-lasting IDO-1 expression and activity in hPDLSCs. The high plasticity of IDO-1 expression and its enzymatic activity in hPDLSCs due to the variable cytokine and virulence factor milieu and the temporal-dependent responsiveness of hPDLSCs may cause a highly dynamic potential of hPDLSCs to modulate immune responses in periodontal tissues.

scholarly journals Novel Cell Type–Specific Antiviral Mechanism of Interferon γ Action in Macrophages

2001 ◽  
Vol 193 (4) ◽  
pp. 483-496 ◽  
Author(s):  
Rachel M. Presti ◽  
Daniel L. Popkin ◽  
Megan Connick ◽  
Susanne Paetzold ◽  
Herbert W. Virgin
Keyword(s):  
Protein Expression ◽  
Mrna Expression ◽  
Interferon Γ ◽  
Murine Cytomegalovirus ◽  
Dependent Manner ◽  
Cell Type ◽  
Mcmv Infection ◽  
A Cell ◽  
Ifn Γ ◽  
Factor Α

Interferon (IFN)-γ and macrophages (Mϕ) play key roles in acute, persistent, and latent murine cytomegalovirus (MCMV) infection. IFN-γ mechanisms were compared in embryonic fibroblasts (MEFs) and bone marrow Mϕ (BMMϕ). IFN-γ inhibited MCMV replication in a signal transducer and activator of transcription (STAT)-1α–dependent manner much more effectively in BMMϕ (∼100-fold) than MEF (5–10-fold). Although initial STAT-1α activation by IFN-γ was equivalent in MEF and BMMϕ, microarray analysis demonstrated that IFN-γ regulates different sets of genes in BMMϕ compared with MEFs. IFN-γ inhibition of MCMV growth was independent of known mechanisms involving IFN-α/β, tumor necrosis factor α, inducible nitric oxide synthase, protein kinase RNA activated (PKR), RNaseL, and Mx1, and did not involve IFN-γ–induced soluble mediators. To characterize this novel mechanism, we identified the viral targets of IFN-γ action, which differed in MEF and BMMϕ. In BMMϕ, IFN-γ reduced immediate early 1 (IE1) mRNA during the first 3 h of infection, and significantly reduced IE1 protein expression for 96 h. Effects of IFN-γ on IE1 protein expression were independent of RNaseL and PKR. In contrast, IFN-γ had no significant effects on IE1 protein or mRNA expression in MEFs, but did decrease late gene mRNA expression. These studies in primary cells define a novel mechanism of IFN-γ action restricted to Mϕ, a cell type key for MCMV pathogenesis and latency.

scholarly journals Effect ofTityus serrulatusvenom on cytokine production and the activity of murine macrophages

2002 ◽  
Vol 11 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Vera L. Petricevich
Keyword(s):  
Cytokine Production ◽  
Peritoneal Macrophages ◽  
Interferon Γ ◽  
Enzyme Linked Immunosorbent Assay ◽  
No Production ◽  
Dependent Manner ◽  
Immune Functions ◽  
Macrophage Activity ◽  
Ifn Γ

The purpose of this study was to investigate the effects ofTityus serrulatusvenom (TSV) on murine peritoneal macrophages evaluated in terms of activation. The effects of crude TSV were analysed by detection of cytokines, oxygen intermediate metabolites (H2O2) and nitric oxide (NO) in supernatants of peritoneal macrophages. Several functional bioassays were employed including anin vitromodel for envenomating: cytotoxicity of TSV was assessed using the lyses percentage. Tumor necrosis factor (TNF) activity was assayed by measuring its cytotoxic activity on L-929 cells, and interleukin-6 (IL-6) and interferon-γ (IFN-γ) were assayed by enzyme-linked immunosorbent assay, whereas NO levels were detected by Griess colorimetric reactions in culture supernatant of macrophages incubated with TSV and subsequently exposed to either lipopolysaccharide or IFN-γ. Incubation of macrophages with TSV increased production of IL-6 and IFN-γ in a dose-dependent manner. TNF production was not detected in supernatants treated with TSV at any concentration. The increase in IL-6 secretion was not associated with concentration-dependent cytoxicity of TSV on these cells. These data suggest that the cytotoxicity does not appear to be the main cause of an increased cytokine production by these cells. Although NO is an important effector molecule in macrophage microbicidal activity, the inducing potential of the test compounds for its release was found to be very moderate, ranging from 125 to 800 mM. Interestingly, NO levels of peritoneal macrophages were increased after IFN-γ. Moreover, NO production had an apparent effect on macrophage activity. The results obtained here also shown that the TSV induces an important elevation in H2O2release. These results combined with NO production suggest that TSV possesses significant immunomodulatory activities capable of stimulating immune functionsin vitro.

Fas/APO-1 (CD95)–Mediated Apoptosis Is Activated by Interferon-γ and Interferon- in Interleukin-6 (IL-6)–Dependent and IL-6–Independent Multiple Myeloma Cell Lines

Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2914-2923 ◽  
Author(s):  
Helena Spets ◽  
Patrik Georgii-Hemming ◽  
Jan Siljason ◽  
Kenneth Nilsson ◽  
Helena Jernberg-Wiklund
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Poor Response ◽  
Antigen Expression ◽  
Myeloma Cell ◽  
Interferon Γ ◽  
Dependent Manner ◽  
Multiple Myeloma Cell ◽  
Ifn Γ ◽  
Induced Apoptosis

Abstract A poor response to Fas-induced apoptosis is evident in some multiple myeloma (MM) cell lines and primary cells. In this study, we have examined the possibility to increase the sensitivity to Fas-induced apoptosis by pretreatment of MM cells with interferon-γ (IFN-γ) or interferon- (IFN-). Both IFN-γ and IFN- markedly increased the Fas-induced apoptosis in all cell lines tested (U-266-1970, U-266-1984, and U-1958). In the U-266-1970 and U-1958 cell lines, pretreatment with either IFN-γ or IFN- also inhibited proliferation in a dose-dependent manner. In contrast, IFN-γ activation of the Fas death pathway in the U-266-1984 cells was not accompanied by growth inhibition. Incubation with the IFNs increased the Fas antigen expression in one of three cell lines but did not alter the expression of Bcl-2 or Bax. The IFNs are important regulators of growth and survival in MM cells. Our results suggest that activation of Fas-mediated apoptosis is a novel mechanism by which the IFNs exert inhibitory effects on MM cells. © 1998 by The American Society of Hematology.

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 Deacetylation of p53 induces autophagy by suppressing Bmf expression

2013 ◽  
Vol 201 (3) ◽  
pp. 427-437 ◽  
Author(s):  
Amelia U. Contreras ◽  
Yohannes Mebratu ◽  
Monica Delgado ◽  
Gilbert Montano ◽  
Chien-an A. Hu ◽  
...  
Keyword(s):  
Cell Death ◽  
Messenger Rna ◽  
Histone Deacetylase Inhibitors ◽  
Interferon Γ ◽  
Airway Epithelial Cells ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Independent Manner ◽  
Rich Domain ◽  
Ifn Γ

Interferon γ (IFN-γ)–induced cell death is mediated by the BH3-only domain protein, Bik, in a p53-independent manner. However, the effect of IFN-γ on p53 and how this affects autophagy have not been reported. The present study demonstrates that IFN-γ down-regulated expression of the BH3 domain-only protein, Bmf, in human and mouse airway epithelial cells in a p53-dependent manner. p53 also suppressed Bmf expression in response to other cell death–stimulating agents, including ultraviolet radiation and histone deacetylase inhibitors. IFN-γ did not affect Bmf messenger RNA half-life but increased nuclear p53 levels and the interaction of p53 with the Bmf promoter. IFN-γ–induced interaction of HDAC1 and p53 resulted in the deacetylation of p53 and suppression of Bmf expression independent of p53’s proline-rich domain. Suppression of Bmf facilitated IFN-γ–induced autophagy by reducing the interaction of Beclin-1 and Bcl-2. Furthermore, autophagy was prominent in cultured bmf−/− but not in bmf+/+ cells. Collectively, these observations show that deacetylation of p53 suppresses Bmf expression and facilitates autophagy.

Vandellia Cordifolia Regulated Cell Proliferation and Cytokines Production in Human Mononuclear Cells

2000 ◽  
Vol 28 (03n04) ◽  
pp. 313-323 ◽  
Author(s):  
An-Pang Lin ◽  
Wei-Jern Tsai ◽  
Chi-Yen Fan ◽  
Ming-Jen Lee ◽  
Yuh-Chi Kuo
Keyword(s):  
Cell Cycle Progression ◽  
Mononuclear Cells ◽  
Tritiated Thymidine ◽  
Interleukin 2 ◽  
Interferon Γ ◽  
Thymidine Uptake ◽  
Dependent Manner ◽  
Human Mononuclear Cells ◽  
Tritiated Thymidine Uptake ◽  
Ifn Γ

Vandellia cordifolia (V. cordifolia) used for treatment inflammation in traditional Chinese medicine was selected for immunopharmacological activity test. The effects of V. cordifolia extracted fractions on human mononuclear cells (HMNC) proliferation were determined by tritiated thymidine uptake. The results indicated that VC-ME fraction suppressed HMNC proliferation activated with phytohemagglutinin (PHA) and stimulated cell cycle progression was arrested at the G0/G1 stage. The inhibitory mechanisms may involve the blocking of interleukin-2 (IL-2) and interferon-γ (IFN-γ) production, since VC-ME suppressed IL-2 and IFN-γ production of HMNC in a dose-dependent manner. Therefore, it is suggested that immunomodulatory agents are contained in V. cordifolia.

Expression of Proteinase Inhibitor-9 in Primary AML Blasts and Its Regulation by Interferon-γ: A Potential Immune Escape Mechanism after Allogeneic Stem Cell Transplantation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3687-3687
Author(s):  
Sabine Hoves ◽  
Alexandra Kolbeck ◽  
Krishna Mondal ◽  
Reinhard Andreesen ◽  
Andreas Mackensen
Keyword(s):  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Immune Escape ◽  
Immune Surveillance ◽  
Hematologic Malignancies ◽  
Interferon Γ ◽  
Dependent Manner ◽  
Ifn Γ ◽  
Immune Escape Mechanisms

Abstract It is well established, that the curative potential of allogeneic peripheral blood stem cell transplantation (allo PBSCT) is due to immunocompetent donor T cells inducing potent anti-neoplastic effects against host tumor cells. This reaction, which is termed graft-versus-leukemia (GVL) effect, is clinically effective against a number of different hematologic malignancies such as myeloid and lymphoid leukemias. Despite great efforts of allo PBSCT in treatment of CML, the 5-year survival rate of AML patients after allo PBSCT is only about 30% due to relapsing disease. The recurrent disease is inefficiently controlled by the immune system, due most likely to the various immune escape mechanisms described for AML blasts including upregulation of anti-apoptotic molecules. Since cytotoxic T lymphocytes (CTL) and natural killer cells are the cells responsible for eliminating leukemic blasts, the most important effector molecule is Granzyme B (GrB). Misdirected GrB is quenched by its specific physiological inhibitor Protease Inhibitor-9 (PI-9) leading to inactivation of GrB. PI-9 expression by tumour cells can be used to escape immune surveillance and its presence has been shown for different tumors e.g. melanoma, colon carcinoma and lymphoma. Despite other regulators, interferon-γ (IFN-γ) has been shown to upregulate PI-9 expression in hepatocytes. Here, we wanted to investigate the expression of PI-9 in primary AML blasts and its regulation by IFN-γ. Using CD34+ positive magnetic selection, we isolated primary blasts with a purity of >90% from 20 AML patients with different FAB subtypes. For detection of PI-9 expression by Western Blotting, whole cell lysates were made from freshly purified blasts and after 24 h +/− 200 IU/ml IFN-γ. In some patients, PI-9 expression was confirmed by FACS analysis with an anti- PI-9 specific monoclonal antibody. Here we describe for the first time, that PI-9 is constitutively expressed in 16/20 (80%) of AML blasts. Treatment of AML blasts with IFN-γ could upregulate PI-9 expression in a dose-dependent manner (2–2,000 IU/ml) and strong expression of PI-9 was detectable in 6/18 patients within 4–5 h after IFN-γ exposure. Of note, a mild upregulation of PI-9 upon 24 h incubation w/o IFN-γ could be detected in 4/18 (22%) patients. We conclude, that cytokines such as IFN-γ which are secreted during the cytokine storm of acute graft-versus-host disease can contribute to the development of immune escape mechanisms in AML blasts.

Up-regulated expression in nonhematopoietic tissues of the BCL2A1-derived minor histocompatibility antigens in response to inflammatory cytokines: relevance for allogeneic immunotherapy of leukemia

Blood ◽  
2005 ◽  
Vol 106 (12) ◽  
pp. 3955-3957 ◽  
Author(s):  
Freke M. Kloosterboer ◽  
Simone A. P. van Luxemburg-Heijs ◽  
Ronald A. van Soest ◽  
H. M. Esther van Egmond ◽  
Roel Willemze ◽  
...  
Keyword(s):  
T Cells ◽  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Interferon Γ ◽  
Hematopoietic Tissue ◽  
Histocompatibility Antigens ◽  
Minor Histocompatibility Antigens ◽  
Tnf Α ◽  
Relative Specificity ◽  
Ifn Γ

T cells directed against hematopoietic-restricted minor histocompatibility antigens (mHags) may mediate graft-versus-leukemia (GVL) reactivity without graft-versus-host disease (GVHD). Recently, the HLA-A24–restricted mHag ACC-1 and the HLA-B44–restricted mHag ACC-2 encoded by separate polymorphisms within the BCL2A1 gene were characterized. Hematopoietic-restricted expression was suggested for these mHags. We demonstrate BCL2-related protein A1 (BCL2A1) mRNA expression in mesenchymal stromal cells (MSCs) that was up-regulated by the inflammatory cytokines tumor necrosis factor α (TNF-α) and/or interferon γ (IFN-γ). Analysis of cytotoxicity and IFN-γ production illustrated that ACC-2–specific T cells did not recognize untreated MSCs or IFN-γ–treated MSCs but showed specific recognition and killing of MSCs treated with TNF-α plus IFN-γ. We hypothesize that under steady-state circumstances BCL2A1-specific T cells may exhibit relative specificity for hematopoietic tissue, but reactivity against nonhematopoietic cells may occur when inflammatory infiltrates are present. Thus, the role of BCL2A1-specific T cells in differential induction of GVL reactivity and GVHD may depend on the presence of inflammatory responses that may occur during GVHD.

scholarly journals Regulation of IL-27 p28 gene expression in macrophages through MyD88- and interferon-γ–mediated pathways

2007 ◽  
Vol 204 (1) ◽  
pp. 141-152 ◽  
Author(s):  
Jianguo Liu ◽  
Xiuqin Guan ◽  
Xiaojing Ma
Keyword(s):  
Transcription Initiation ◽  
Gene Promoter ◽  
Nuclear Factor Κb ◽  
Interferon Γ ◽  
Dependent Manner ◽  
Barr Virus ◽  
Ifn Γ ◽  
Epstein Barr ◽  
Activated Monocytes ◽  
Myeloid Differentiation Factor

Interleukin (IL)-27 is the newest member of the IL-12 family of heterodimeric cytokines composed of the Epstein-Barr virus–induced gene 3 and p28 chains. IL-27 not only plays an important role in the regulation of differentiation of naive T helper cells but also possesses antiinflammatory properties. IL-27 is an early product of activated monocytes/macrophages and dendritic cells. However, the mechanisms whereby inflammatory signals stimulate IL-27 production have not been explored. In this study, we investigated the transcriptional regulation of the mouse IL-27 p28 gene in macrophages in response to lipopolysaccharide (LPS) and interferon (IFN)-γ. We found that LPS-stimulated p28 production was completely dependent on the Toll-like receptor 4/myeloid differentiation factor 88 (MyD88)–mediated pathway but only partially dependent on nuclear factor κB c-Rel. IFN-γ–induced p28 production/secretion was also partially dependent on MyD88 but independent of c-Rel. We then cloned the mouse p28 gene promoter and mapped its multiple transcription initiation sites. Furthermore, we identified critical promoter elements that mediate the inductive effects of LPS and IFN-γ, separately and synergistically, on p28 gene transcription in a c-Rel– and interferon regulatory factor 1–dependent manner, respectively.

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