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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We recently discovered that a ubiquitous protein, high mobility group box 1 protein (HMGB1), is released by activated macrophages, and functions as a late mediator of lethal systemic inflammation. To elucidate mechanisms underlying the regulation of HMGB1 release, we examined the roles of other cytokines in induction of HMGB1 release in macrophage cell cultures. Macrophage migration inhibitory factor, macrophage-inflammatory protein 1beta, and IL-6 each failed to significantly induce the release of HMGB1 even at supraphysiological levels (up to 200 ng/ml).
IFN-gamma
, an immunoregulatory cytokine known to mediate the innate immune response, dose-dependently induced the release of HMGB1, TNF, and NO, but not other cytokines such as IL-1alpha, IL-1beta, or IL-6. Pharmacological suppression of TNF activity with neutralizing Abs, or genetic disruption of TNF expression (TNF knockout) partially (50-60%) inhibited
IFN-gamma
-mediated HMGB1 release. AG490, a specific inhibitor for
Janus kinase 2
of the
IFN-gamma
signaling pathway, dose-dependently attenuated
IFN-gamma
-induced HMGB1 release. These data suggest that
IFN-gamma
plays an important role in the regulation of HMGB1 release through a TNF- and
Janus kinase 2
-dependent mechanism.
...
PMID:IFN-gamma induces high mobility group box 1 protein release partly through a TNF-dependent mechanism. 1264 58
Interleukin-2 (IL-2) and interleukin-12 (IL-12) belong to lympho-hematopoietic cytokines and play a critical role in the promotion and enhancement of cellular response. IL-2 as the second signal of antigenic stimulation facilitates the transition of the cell cycle from phase G1 to phase S and is responsible for the regulation of T lymphocytes proliferation and the activation of cytotoxic T cells, natural killers, macrophages and granulocytes. IL-12 is the dominant factor in T helper cells polarization leading to the secretion of
IFN-gamma
. Receptors for both of the cytokines (IL-2R or IL-12R) represent class I cytokine receptors composed of multiple subunits. Generally, they contain a similar extracellular conserved motif of four cysteines, and amino acid sequence--WSXWS (interacting directly with ligand) but possess no catalytic domens in the intrinsic tail of the chains. For this reason, to transfer the impact, the association with number of signaling molecules, allowing the activation of the signaling pathways is required. The connections of IL-2R or IL-12R with their ligands recruit receptor-associated cytoplasmic proteins from the JAK family (
JAK1
/
JAK3
or
JAK2
/
TYK2
, respectively), which catalyze the phosphorylation of themselves and intrinsic tyrosine residues on the receptor, creating STAT docking sites. This phosphorylated and subsequent dimerised proteins bind rapidly to DNA and activate it. This review, presents the differences and similarities between the signaling pathways triggered by IL-2R or IL-12R ligation.
...
PMID:[Contribution of interleukin 2 and interleukin 12 receptors in signal transduction during cell activation of the immune system]. 1266 3
We established hepatitis C virus (HCV) core-expressing cells and investigated whether HCV core would modify the Janus kinase (JAK)-signal transducer and activator transcription factor (STAT) pathway under interleukin-6 (IL-6) and interferon (IFN)-gamma stimuli. Phosphorylation of
JAK1
/2 and STAT3, and STAT3-mediated transcription, were prevented by HCV core under IL-6 stimulation. In contrast, HCV core increased phosphorylation of
JAK1
/2 and STAT1 and STAT1-mediated transcription under
IFN-gamma
stimulation. Immunoprecipitation/Western blot analysis showed that HCV core could bind to
JAK1
/2. The PGYPWP sequences at codons 79-84 within HCV core were important for interaction with JAKs by in vitro binding analysis. In the reporter gene assay, HCV core-mediated suppression of JAK-STAT pathway under IL-6 stimulation was not observed by abrogation of PGYPWP sequence, suggesting that HCV core/JAK interaction may directly affect the signal transduction. In contrast, augmentation of JAK-STAT pathway was still seen by HCV core without functional PGYPWP sequence under
IFN-gamma
stimulation. Flow cytometric analysis revealed that HCV core up-regulated of
IFN-gamma
receptor 2 expression, which may be responsible for HCV core-mediated enhancement of JAK-STAT pathway under
IFN-gamma
stimulation. In conclusion, HCV core has different effects on the JAK-STAT pathway under IL-6 and
IFN-gamma
stimuli. This may be exerted by these two independent mechanisms.
...
PMID:Hepatitis C virus core protein differently regulates the JAK-STAT signaling pathway under interleukin-6 and interferon-gamma stimuli. 1276 55
Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have been reported to exert anti-inflammatory activities in macrophages by competition for transcriptional coactivators with some transcriptional factors, including NF-kappaB. In the present study the influence of PPARgamma activators on
IFN-gamma
-elicited macrophage stimulation and signaling cascades was investigated. The results show that
IFN-gamma
-induced inducible NO synthase (iNOS) gene transcription, iNOS protein induction, and NO production are more sensitive to inhibition by 15-deoxy-Delta(12,14)-prostaglandin J(2) (15dPGJ(2)) than by the other two PPARgamma agonists, GW1929 and ciglitazone. Delayed addition of 15dPGJ(2) for 2 h resulted in reduced inhibition, suggesting action by 15dPGJ(2) on the upstream signaling cascades. Immunoblotting, DNA binding, and reporter gene assays consistently revealed the inhibitory ability of 15dPGJ(2), but not GW1929 or ciglitazone, on
IFN-gamma
-elicited signaling cascades, including tyrosine phosphorylation of Janus tyrosine protein kinase 2 and STAT1, DNA binding, and IFN regulatory factor-1 trans-activation of STAT1. These effects of 15dPGJ(2) were not abrogated by the PPARgamma antagonist, bisphenol A diglycidyl ether, indicating the PPARgamma-independent actions. 15dPGJ(2) also attenuated IL-6-induced tyrosine phosphorylation of STAT1 and STAT3 in Hep3B hepatoma cells. Consistent with the inhibitory effect of reactive oxygen species on STAT1 signaling, STAT1 inhibition by 15dPGJ(2) was abrogated by N-acetylcysteine, glutathione, superoxide dismutase, and catalase. Furthermore, 15dPGJ(2)-induced inhibition of STAT1 phosphorylation and NO production still occurred in the presence of peroxovanadate, ruling out the action mechanism of 15dPGJ(2) on tyrosine phosphatase. Taken together, for the first time in this study we demonstrate that 15dPGJ(2) can inhibit cytokine-stimulated
Janus kinase 2
-STAT signaling through a PPARgamma-independent, reactive oxygen species-dependent mechanism. These data provide a novel molecular mechanism of iNOS inhibition by 15dPGJ(2) and confirm its physiological role in anti-inflammation.
...
PMID:Inhibition of IFN-gamma-mediated inducible nitric oxide synthase induction by the peroxisome proliferator-activated receptor gamma agonist, 15-deoxy-delta 12,14-prostaglandin J2, involves inhibition of the upstream Janus kinase/STAT1 signaling pathway. 1284 70
IL-12 is a key immunoregulatory cytokine that promotes Th1 differentiation and cell-mediated immune responses. IL-12 stimulation results in the activation of
Janus kinase 2
and tyrosine kinase 2 and, subsequently, STAT4 and STAT3. In addition, mitogen-activated protein kinase kinase 6/p38 mitogen-activated protein kinase and phosphatidylinositol 3-kinase/Akt pathways have been recently demonstrated to be activated by IL-12 and play an important role in IL-12 signaling. To further elucidate the molecular mechanism underlying IL-12 signaling, we have performed a yeast two-hybrid screening and identified mouse sphingosine kinase 2 (SPHK2) as a molecule associating with the mouse IL-12Rbeta1 cytoplasmic region. Analyses of various mutants of each molecule revealed that the region including the proline-rich domain in SPHK2 is probably responsible for the binding to IL-12Rbeta1, while the regions including the carboxyl terminus and Box II in the IL-12Rbeta1 cytoplasmic region appear to be involved in the binding to SPHK2. Transient expression of wild-type SPHK2 in T cell hybridoma augmented IL-12-induced STAT4-mediated transcriptional activation. Ectopic expression of dominant-negative SPHK2 in Th1 cell clone significantly reduced IL-12-induced
IFN-gamma
production, while that of wild-type SPHK2 enhanced it. In contrast, the expression minimally affected IL-12-induced proliferation. A similar decrease in IL-12-induced
IFN-gamma
production was observed when dominant-negative SPHK2 was expressed in activated primary T cells using a retroviral expression system. These results suggest that SPHK2 associates with the IL-12Rbeta1 cytoplasmic region and probably plays a role in modulating IL-12 signaling.
...
PMID:Positive modulation of IL-12 signaling by sphingosine kinase 2 associating with the IL-12 receptor beta 1 cytoplasmic region. 1287 25
The short chain fatty acid butyrate promotes proliferation and survival of normal epithelial cells, but induces G(1) or G(2)-M arrest in transformed cells, which is coupled to differentiation and apoptosis. Local administration of butyrate has been shown to ameliorate inflammation in ulcerative colitis; however, the precise mechanism of its anti-inflammatory activity is not known.
IFN-gamma
is one of the principle cytokines secreted by lamina propria cells in inflamed mucosa and elevated levels of the transcription factor required for
IFN-gamma
signaling, STAT1 (signal transducer and activator of transcription 1), are present in the colonic mucosa of patients with ulcerative colitis and Crohn's disease. Here we report that butyrate is a strong inhibitor of signaling by
IFN-gamma
. We demonstrated that this short chain fatty acid inhibits
IFN-gamma
-induced tyrosine and serine phosphorylation of STAT1.
IFN-gamma
-induced
JAK2
activation was inhibited by butyrate, implicating
JAK2
as a target of butyrate action. Accordingly, STAT1 nuclear translocation and its DNA binding were completely inhibited in butyrate-treated cells. Transient transfection experiments using a reporter gene construct containing eight GAS sites (gamma-activated sites) revealed that butyrate inhibits
IFN-gamma
induced, STAT1-dependent, transcriptional activation. Proinflammatory cytokines, including
IFN-gamma
, play an important role in the pathogenesis of inflammatory bowel disease, and abnormal activity of STAT1 is associated with human malignancies and intestinal inflammatory diseases. Thus, our data suggest that butyrate negatively regulates mucosal inflammation through the inhibition of
IFN-gamma
/STAT1 signaling.
...
PMID:Inhibition of interferon gamma signaling by the short chain fatty acid butyrate. 1451 48
NO overproduction has been suggested to contribute to the immunopathology related to malaria infection. Even though a role for some parasite molecules (e.g., GPI) in NO induction has been proposed, the direct contribution of hemozoin (HZ), another parasite metabolite, remains to be established. Therefore, we were interested to determine whether Plasmodium falciparum (Pf) HZ and synthetic HZ, beta-hematin, alone or in combination with
IFN-gamma
, were able to induce macrophage (Mphi) NO synthesis. We observed that neither Pf HZ nor synthetic HZ led to NO generation in B10R murine Mphi; however, they significantly increased
IFN-gamma
-mediated inducible NO synthase (iNOS) mRNA and protein expression, and NO production. Next, by investigating the transductional mechanisms involved in this cellular regulation, we established that HZ induces extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase phosphorylation as well as NF-kappaB binding to the iNOS promoter, and enhances the
IFN-gamma
-dependent activation of both second messengers. Of interest, cell pretreatment with specific inhibitors against either NF-kappaB or the ERK1/2 pathway blocked the HZ +
IFN-gamma
-inducible NF-kappaB activity and significantly reduced the HZ-dependent increase on
IFN-gamma
-mediated iNOS and NO induction. Even though selective inhibition of the
Janus kinase 2
/STAT1alpha pathway suppressed NO synthesis in response to HZ +
IFN-gamma
, HZ alone did not activate this signaling pathway and did not have an up-regulating effect on the
IFN-gamma
-induced
Janus kinase 2
/STAT1alpha phosphorylation and STAT1alpha binding to the iNOS promoter. In conclusion, our results suggest that HZ exerts a potent synergistic effect on the
IFN-gamma
-inducible NO generation in Mphi via ERK- and NF-kappaB-dependent pathways.
...
PMID:Hemozoin increases IFN-gamma-inducible macrophage nitric oxide generation through extracellular signal-regulated kinase- and NF-kappa B-dependent pathways. 1453 Mar 48
The in vitro effect of gamma interferon (
IFN-gamma
) on nitric oxide (NO) production in a mouse CD5+ B1-like cell line, TH2.52, was studied. The TH2.52 cell line is the hybridoma line between mouse B lymphoma line and mouse splenic B cells and expresses a series of B1 markers.
IFN-gamma
induced a marked NO production in TH2.52 cells through the expression of an inducible type of NO synthase (iNOS).
IFN-gamma
-induced NO production was triggered by the Janus tyrosine kinase (JAK)/signal transducer and activator of transcription (STAT) pathway since it was inhibited by AG490, a
JAK2
inhibitor. The growth of TH2.52 cells significantly was inhibited in the presence of
IFN-gamma
. A significant number of cells underwent apoptotic cell death, accompanied by the DNA fragmentation, annexin V binding, and caspase 3 activation. N(G)-monomethyl-L-arginine, an iNOS inhibitor, prevented
IFN-gamma
-induced cell death. Therefore,
IFN-gamma
-induced NO production was possible in causing cell death in TH2.52 cells. Further,
IFN-gamma
-induced NO production and cell death significantly were prevented by interleukin-4, a representative Th2 cytokine. The immunological significance of
IFN-gamma
-induced NO production in a mouse B1-like cell line is discussed.
...
PMID:Gamma interferon-induced nitric oxide production in mouse CD5+ B1-like cell line and its association with apoptotic cell death. 1458 14
IFN-gamma
rapidly primes the macrophage via
JAK1
/2-STAT1 pathway so that it can subsequently undergo a slower classical type 1 activation upon exposure to T helper (Th)1 cytokines such as IFNgamma or other activators, including tumor necrosis factor and lipopolysaccharide, e.g. in intracellular killing of phagocytosed Mycobacterium tuberculosis. If instead it is driven by Th2 cytokines interleukin (IL)-4 and IL-13, it undergoes alternate type 2 activation, which enhances endocytotic antigen uptake and presentation, mast cell and eosinophil involvement and type 2 granuloma formation, e.g. in response to parasitic and extracellular pathogens. Particle-induced macrophage activation was shown to differ from classical and alternate activation, showing in DNA microarray experiments (complete linkage/ Euclidean distance metric analysis) upregulation of nonsecreted structural/signaling molecules and lack of secreted proinflammatory cyto- and chemokines. The switch-off (deactivation) of already activated macrophages is an active, controlled process in which IL-10 and corticosteroids play important roles and to which 15dPGJ2, PGA1/2 and vasoactive intestinal peptide often contribute.
...
PMID:Regulation of macrophage activation. 1462 80
Curcumin has been strongly implicated as an anti-inflammatory agent, but the precise mechanisms of its action are largely unknown. In this study, we show that the inhibitory action of curcumin on Janus kinase (JAK)-STAT signaling can contribute to its anti-inflammatory activity in the brain. In both rat primary microglia and murine BV2 microglial cells, curcumin effectively suppressed the ganglioside-, LPS-, or
IFN-gamma
-stimulated induction of cyclooxygenase-2 and inducible NO synthase, important enzymes that mediate inflammatory processes. These anti-inflammatory effects appear to be due, at least in part, to the suppression of the JAK-STAT inflammatory signaling cascade. Curcumin markedly inhibited the phosphorylation of STAT1 and 3 as well as
JAK1
and 2 in microglia activated with gangliosides, LPS, or
IFN-gamma
. Curcumin consistently suppressed not only NF binding to
IFN-gamma
-activated sequence/IFN-stimulated regulatory element, but also the expression of inflammation-associated genes, including ICAM-1 and monocyte chemoattractant protein 1, whose promoters contain STAT-binding elements. We further show that activation of Src homology 2 domain-containing protein tyrosine phosphatases (SHP)-2, a negative regulator of JAK activity, is likely to be one of the mechanisms underlying the curcumin-mediated inhibition of JAK-STAT signaling. Treatment of microglial cells with curcumin led to an increase in phosphorylation and association with
JAK1
/2 of SHP-2, which inhibit the initiation of JAK-STAT inflammatory signaling in activated microglia. Taken together, these data suggest curcumin suppresses JAK-STAT signaling via activation of SHP-2, thus attenuating inflammatory response of brain microglial cells.
...
PMID:Curcumin suppresses Janus kinase-STAT inflammatory signaling through activation of Src homology 2 domain-containing tyrosine phosphatase 2 in brain microglia. 1463 21
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