STAT1 plays an essential role in LPS/D-galactosamine-induced liver apoptosis and injury

2003 ◽  
Vol 285 (4) ◽  
pp. G761-G768 ◽  
Author(s):  
Won-Ho Kim ◽  
Feng Hong ◽  
Svetlana Radaeva ◽  
Barbara Jaruga ◽  
Saijun Fan ◽  
...  
Keyword(s):  
Cell Death ◽  
Essential Role ◽  
Underlying Mechanism ◽  
Interferon Γ ◽  
Dominant Negative ◽  
Hepatitis C Infection ◽  
Hepatocellular Damage ◽  
Tnf Α ◽  
Hep3b Cells ◽  
Ifn Γ

Interferon-γ (IFN-γ) has been implicated in liver damage in animal models and chronic hepatitis C infection; however, the underlying mechanism is not clear. Here we examined the role of STAT1, a key signaling molecule for IFN-γ, in a model of murine hepatitis induced by the injection of LPS/d-galactosamine and in human hepatoma Hep3B cells. STAT1 is rapidly activated and highly induced after injection of LPS/d-galactosamine. Both overexpression of STAT1 and hepatocellular damage are located in the same pericentral region. Disruption of the STAT1 gene abolishes LPS/d-galactosamine-induced liver injury. Studies from IFN-γ-deficient mice indicate that IFN-γ is the major cytokine responsible for activation and hyperexpression of STAT1 in LPS/d-galactosamine-induced hepatitis. Hep3B cells overexpressing dominant negative STAT1 are resistant to IFN-γ and IFN-γ + TNF-α-induced cell death, whereas Hep3B cells overexpressing wild-type STAT1 are more susceptible to cell death. Taken together, these findings suggest that STAT1 plays an essential role in LPS/d-galactosamine-induced liver apoptosis and injury.

High Serum Levels of CXCL11 in Mixed Cryoglobulinemia Are Associated with Increased Circulating Levels of Interferon-γ

2011 ◽  
Vol 38 (9) ◽  
pp. 1947-1952 ◽  
Author(s):  
ALESSANDRO ANTONELLI ◽  
CLODOVEO FERRI ◽  
SILVIA MARTINA FERRARI ◽  
ILARIA RUFFILLI ◽  
MICHELE COLACI ◽  
...  
Keyword(s):  
Strong Relationship ◽  
Serum Levels ◽  
Mixed Cryoglobulinemia ◽  
Interferon Γ ◽  
High Serum ◽  
Hepatitis C Infection ◽  
T Helper 1 ◽  
Tnf Α ◽  
Ifn Γ ◽  
Factor Α

Objective.No study has evaluated circulating chemokine C-X-C motif ligand (CXCL)11 in patients with “mixed cryoglobulinemia and chronic hepatitis C infection” (MC+HCV). We measured CXCL11, and correlated this measurement to the clinical phenotype.Methods.Serum CXCL11, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) were assayed in 97 MC+HCV patients and in 97 sex- and age-matched controls.Results.MC+HCV patients showed significantly higher mean CXCL11 serum levels than controls (254 ± 295, 68 ± 16 pg/ml, respectively; p = 0.0002; ANOVA). CXCL11 was significantly increased in 36 cryoglobulinemic patients with compared to those without active vasculitis (303 ± 208 vs 179 ± 62 pg/ml, respectively; p < 0.001; ANOVA). IFN-γ levels were significantly higher in MC+HCV than in controls [6.1 (range 0.8–114.5), 1.4 (range 0.7–2.4) pg/ml, respectively; p < 0.05; Mann-Whitney U test]. Serum TNF-α mean levels were significantly higher in MC+HCV than in controls [13.4 (range 1.8–369), 1.1 (range 0.7–3.2) pg/ml, respectively; p < 0.0001; Mann-Whitney U test]. A multiple regression analysis considering CXCL11 as a dependent variable, and age, alanine aminotransferase, IFN-γ, and TNF-α as independent variables, showed in MC+HCV patients a significant association only with IFN-γ (p < 0.0001).Conclusion.Our study demonstrates markedly high serum levels of CXCL11 in patients with MC+HCV compared to healthy controls overall in the presence of active vasculitis. A strong relationship between circulating IFN-γ and CXCL11 was shown, strongly supporting the role of a T helper 1 immune response in the pathogenesis of MC+HCV.

IFN-γ + LPS induction of iNOS is modulated by ERK, JNK/SAPK, and p38 mapk in a mouse macrophage cell line

2001 ◽  
Vol 280 (3) ◽  
pp. C441-C450 ◽  
Author(s):  
Edward D. Chan ◽  
David W. H. Riches
Keyword(s):  
Nitric Oxide ◽  
Cell Line ◽  
Inhibitory Effect ◽  
Interferon Γ ◽  
Dominant Negative ◽  
Jnk Pathway ◽  
Mutant Proteins ◽  
Inos Promoter ◽  
Ifn Γ ◽  
Inos Induction

Nitric oxide (NO·) produced by inducible nitric oxide synthase (iNOS) mediates a number of important physiological and pathophysiological processes. The objective of this investigation was to examine the role of mitogen-activated protein kinases (MAPKs) in the regulation of iNOS and NO· by interferon-γ (IFN-γ) + lipopolysaccharide (LPS) in macrophages using specific inhibitors and dominant inhibitory mutant proteins of the MAPK pathways. The signaling pathway utilized by IFN-γ in iNOS induction is well elucidated. To study signaling pathways that are restricted to the LPS-signaling arm, we used a subclone of the parental RAW 264.7 cell line that is unresponsive to IFN-γ alone with respect to iNOS induction. In this RAW 264.7γNO(−) subclone, IFN-γ and LPS are nevertheless required for synergistic activation of the iNOS promoter. We found that extracellular signal-regulated kinase (ERK) augmented and p38 mapk inhibited IFN-γ + LPS induction of iNOS. Dominant-negative MAPK kinase-4 inhibited iNOS promoter activation by IFN-γ + LPS, also implicating the c-Jun NH2-terminal kinase (JNK) pathway in mediating iNOS induction. Inhibition of the ERK pathway markedly reduced IFN-γ + LPS-induced tumor necrosis factor-α protein expression, providing a possible mechanism by which ERK augments iNOS expression. The inhibitory effect of p38 mapk appears more complex and may be due to the ability of p38 mapk to inhibit LPS-induced JNK activation. These results indicate that the MAPKs are important regulators of iNOS-NO· expression by IFN-γ + LPS.

Increased cytochrome P-450 2E1 expression sensitizes hepatocytes to c-Jun-mediated cell death from TNF-α

2002 ◽  
Vol 282 (2) ◽  
pp. G257-G266 ◽  
Author(s):  
Hailing Liu ◽  
Brett E. Jones ◽  
Cynthia Bradham ◽  
Mark J. Czaja
Keyword(s):  
Cell Death ◽  
Oxidant Stress ◽  
Nuclear Factor Κb ◽  
Dominant Negative ◽  
Tnf Α ◽  
Cyp2e1 Expression ◽  
Factor Α ◽  
Jnk Activation ◽  
Cytochrome P 450 ◽  
Necrosis Factor

The mechanisms underlying hepatocyte sensitization to tumor necrosis factor-α (TNF-α)-mediated cell death remain unclear. Increases in hepatocellular oxidant stress such as those that occur with hepatic overexpression of cytochrome P-450 2E1 (CYP2E1) may promote TNF-α death. TNF-α treatment of hepatocyte cell lines with differential CYP2E1 expression demonstrated that overexpression of CYP2E1 converted the hepatocyte TNF-α response from proliferation to apoptotic and necrotic cell death. Death occurred despite the presence of increased levels of nuclear factor-κB transcriptional activity and was associated with increased lipid peroxidation and GSH depletion. CYP2E1-overexpressing hepatocytes had increased basal and TNF-α-induced levels of c-Jun NH2-terminal kinase (JNK) activity, as well as prolonged JNK activation after TNF-α stimulation. Sensitization to TNF-α-induced cell death by CYP2E1 overexpression was inhibited by antioxidants or adenoviral expression of a dominant-negative c-Jun. Increased CYP2E1 expression sensitized hepatocytes to TNF-α toxicity mediated by c-Jun and overwhelming oxidative stress. The chronic increase in intracellular oxidant stress created by CYP2E1 overexpression may serve as a mechanism by which hepatocytes are sensitized to TNF-α toxicity in liver disease.

Clinical significance of cytokine markers in children with different courses of community-acquired pneumonia

2020 ◽  
Vol 15 (5) ◽  
pp. 18-23
Author(s):  
G.P. Evseeva ◽  
◽  
G.N. Kholodok ◽  
S.V. Pichugina ◽  
S.V. Suprun ◽  
...  
Keyword(s):  
Cytokine Production ◽  
Interleukin 1 ◽  
Interferon Γ ◽  
Peripheral Blood Lymphocytes ◽  
Community Acquired Pneumonia ◽  
Enzyme Linked Immunosorbent Assay ◽  
Interleukin 17 ◽  
Monocyte Chemoattractant Protein 1 ◽  
Tnf Α ◽  
Ifn Γ

Principles of the diagnosis and treatment of community-acquired pneumonia (CAP) in children were developed and clearly formulated long ago. Nevertheless, clinicians often encounter the problem of pulmonary and pleural complications of CAP, which is challenging in terms of the choice of initial therapy, since the first symptoms of uncomplicated and complicated pneumonia are often similar. Therefore, the search for early markers of complicated CAP in children is highly important. Objective. To assess prognostic values of spontaneous and mitogen-induced cytokine production in children with CAP. Patients and methods. We have performed comprehensive examination of 108 children with CAP. Eighty-four of them had uncomplicated CAP, whereas 24 children had CAP complicated by pleurisy. We measured spontaneous and induced production of the following cytokines upon patient admission to hospital: interleukin-1 (IL-1), interleukin-17 (IL-17), interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1). To measure induced cytokine production, we stimulated peripheral blood lymphocytes by S. рneumonае (serotype 7, 11; strains 7C and 11AD). The level of cytokines was evaluated using the enzyme-linked immunosorbent assay (Vektor-BEST, Novosibirsk, Russia). Results. We found that in children with uncomplicated CAP, induction of immunocompetent blood cells (IBCs) led to increased secretion of first-generation cytokines, including IL-1, TNF-α, and IFN-γ, whereas IBCs of patients with complicated CAP primarily produced second-generation cytokines, including VEGF, МРС-1, and IL-17. Conclusion. The observed differences in spontaneous and mitogen-induced cytokine production between children with and without CAP complications suggest that these parameters can be considered as promising prognostic markers for complicated CAP in children. The proposed method can be used in pediatric practice to predict the development of complications in children with CAP. Key words: children, community-acquired pneumonia, cytokines

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.

Regulation of intracellular polyamine biosynthesis and transport by NO and cytokines TNF-α and IFN-γ

1999 ◽  
Vol 276 (4) ◽  
pp. C892-C899 ◽  
Author(s):  
Joseph Satriano ◽  
Shunji Ishizuka ◽  
D. Clay Archer ◽  
Roland C. Blantz ◽  
Carolyn J. Kelly
Keyword(s):  
Cellular Proliferation ◽  
Interferon Γ ◽  
Experimental Models ◽  
Proximal Tubule Cell ◽  
Polyamine Biosynthesis ◽  
No Donors ◽  
Temporal Regulation ◽  
Tnf Α ◽  
Ifn Γ ◽  
Factor Α

Nitric oxide (NO) has been described to exert cytostatic effects on cellular proliferation; however the mechanisms responsible for these effects have yet to be fully resolved. Polyamines, conversely, are required components of cellular proliferation. In experimental models of inflammation, a relationship between these two pathways has been suggested by the temporal regulation of a common precursor, arginine. This study was undertaken to determine the effects NO and the NO synthase (NOS)-inducing cytokines, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), exert on polyamine regulation. The transformed kidney proximal tubule cell line, MCT, maintains high constitutive levels of the first polyamine biosynthetic enzyme, ornithine decarboxylase (ODC). NO donors markedly suppressed ODC activity in MCT and all other cell lines examined. TNF-α and IFN-γ induction of NO generation resulted in suppressed ODC activity, an effect prevented by the inducible NOS inhibitorl- N 6-(1-iminoethyl)lysine (l-NIL). Dithiothreitol reversal of NO-mediated ODC suppression supports nitrosylation as the mechanism of inactivation. We also evaluated polyamine uptake, inasmuch as inhibition of ODC can result in a compensatory induction of polyamine transporters. Administration of NO donors, or TNF-α and IFN-γ, suppressed [3H]putrescine uptake, thereby preventing transport-mediated reestablishment of intracellular polyamine levels. This study demonstrates the capacity of NO and inflammatory cytokines to regulate both polyamine biosynthesis and transport.

Mesenchymal stromal cell plasticity and the tumor microenvironment

2017 ◽  
Vol 1 (5) ◽  
pp. 487-492
Author(s):  
Hee Joon Bae ◽  
Shutong Liu ◽  
Ping Jin ◽  
David Stroncek
Keyword(s):  
Tumor Microenvironment ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Tumor Infiltrating Lymphocytes ◽  
Transforming Growth Factor Β ◽  
Interferon Γ ◽  
Tnf Α ◽  
Ifn Γ ◽  
Factor Α ◽  
Infiltrating Lymphocytes

Mesenchymal stem cells or mesenchymal stromal cells (MSCs) are a multipotent, heterogeneous population of cells that play a critical role in wound healing and tissue regeneration. MSCs, found in the tumor microenvironment, support tumor growth through the production of angiogenic factors, growth factors and extracellular matrix proteins. They also have immunomodulatory properties, and since they produce indoleamine 2,3-dioxygenase (IDO), prostaglandin E2 (PGE2) and transforming growth factor β (TGF-β), they have been thought to have primarily immunosuppressive effects. However, their role in the tumor microenvironment is complex and demonstrates plasticity depending on location, stimulatory factors and environment. The presence of melanoma-activated tumor-infiltrating lymphocytes (TILs) has been shown to produce pro-inflammatory changes with TH1 (type 1T helper)-like phenotype in MSCs via activated-TIL released cytokines such as interferon γ (IFN-γ), tumor necrosis factor α (TNF-α) and interleukin-1α (IL-1α), while simultaneously producing factors, such as IDO1, which have been traditionally associated with immunosuppression. Similarly, the combination of IFN-γ and TNF-α polarizes MSCs to a primarily TH1-like phenotype with the expression of immunosuppressive factors. Ultimately, further studies are encouraged and needed for a greater understanding of the role of MSCs in the tumor microenvironment and to improve cancer immunotherapy.

Role of NF-κB in β-cell death

2008 ◽  
Vol 36 (3) ◽  
pp. 334-339 ◽  
Author(s):  
Danielle Melloul
Keyword(s):  
Cell Death ◽  
Lymphocytic Infiltration ◽  
Nuclear Factor Κb ◽  
Interferon Γ ◽  
Cell Protection ◽  
Β Cells ◽  
Β Cell ◽  
Ifn Γ ◽  
Induced Apoptosis

Apoptotic β-cell death appears to be central to the pathogenesis of Type 1 diabetes mellitus and in islet graft rejection. The β-cell destruction is partially mediated by cytokines, such as IL-1β (interleukin 1β), TNFα (tumour necrosis factor α) and IFN-γ (interferon γ). IL-1β and TNFα mediate activation of the transcription factor NF-κB (nuclear factor κB) pathway. Use of a degradation-resistant NF-κB protein inhibitor (ΔNIκBα), specifically expressed in β-cells, significantly reduced IL-1β+IFN-γ-induced apoptosis. Moreover, in vivo, it protected against multiple low-dose streptozocin-induced diabetes, with reduced intra-islet lymphocytic infiltration. Thus β-cell-specific activation of NF-κB is a key event in the progressive loss of β-cells in diabetes. Inhibition of this process could be a potential effective strategy for β-cell protection.

T-bet Down-Modulation in Tolerized Th1 Effector CD4 Cells Confers a TCR-Distal Signaling Defect That Selectively Impairs IFN- γ Expression.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3321-3321
Author(s):  
Meixiao Long ◽  
Aaron M. Slaiby ◽  
Adam T. Hagymasi ◽  
Marianne A. Mihalyo ◽  
Alexander C. Lichtler ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Dominant Negative ◽  
Cd4 Cells ◽  
Tnf Α ◽  
Ifn Γ ◽  
Effector Cytokines ◽  
Expression Potential ◽  
Proximal Signaling ◽  
Cd4 Cell

Abstract When Th1 effector CD4 cells encounter tolerizing antigen in vivo their capacity to express the effector cytokines IFN-γ and TNF-α is lost more rapidly than non-effector functions such as IL-2 production and proliferation. To localize the relevant intracellular signaling defects, cytokine expression was compared following restimulation with antigen vs agents that bypass TCR-proximal signaling. IFN-γ and TNF-α expression were both partially rescued when TCR-proximal signaling was bypassed, indicating that both TCR-proximal and distal signaling defects impair the expression of these two effector cytokines. In contrast, bypassing TCR-proximal signaling fully rescued IL-2 expression. T-bet, a transcription and chromatin remodeling factor that is required to direct the differentiation of naive CD4 cells into IFN-γ-expressing Th1 effectors, was partially down-modulated in tolerized Th1 effectors. Enforcing T-bet expression during tolerization selectively rescued the ability to express IFN-γ, but not TNF-α. Conversely, expression of a dominant-negative T-bet in Th1 effectors selectively impaired the ability to express IFN-γ, but not TNF-α. Analysis of histone acetylation at the IFN-γ promoter further suggests that down-modulation of T-bet expression during Th1 effector CD4 cell tolerization does not impair IFN γ expression potential through alterations in chromatin structure.

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