Critical Role of the Carboxyl Terminus of Proline-rich Tyrosine Kinase (Pyk2) in the Activation of Human Neutrophils by Tumor Necrosis Factor

Han, Hee‐Sun; Fuortes, Michele; Nathan, Carl

doi:10.1084/jem.20021638

Cited by 53 publications

(82 citation statements)

References 76 publications

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“…Although other investigators have reported that piceatannol is a specific inhibitor of Syk, studies based on piceatannol alone are not sufficient to implicate Syk in cytokine signaling (Oliver et (19), it is possible that TNF-induced activation of Syk is through PI3K. Because TNF-induced PI3K activation could be seen only after 15 min of TNF treatment (47) and TNF-induced Syk activation occurred within 30 s, it is unlikely that PI3K activation preceded Syk activation.…”

Section: Discussionmentioning

confidence: 75%

“…Proline-rich tyrosine kinase (Pyk2) 3 (18,19) and p53/Lyn p56 (20) have roles in TNF-induced neutrophil activation; Etk/Bmx in TNF-induced endothelial cell migration and angiogenesis; c-Src in TNF-induced NF-B activation in the marrow macrophages (21,22); and TNF in regulation of gap junctions in airway epithelial cells (23). Pyk2 has also been implicated in TNF-induced JNK activation (24).…”

Section: Tnf Activates Syk Proteinmentioning

confidence: 99%

“…Pyk2 has also been implicated in TNF-induced JNK activation (24). In neutrophils, TNF has been shown to promote the association of Pyk2 to spleen tyrosine kinase (Syk) (19) and activate Syk, one of the downstream targets of Pyk2 (25).…”

Section: Tnf Activates Syk Proteinmentioning

confidence: 99%

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TNF Activates Syk Protein Tyrosine Kinase Leading to TNF-Induced MAPK Activation, NF-κB Activation, and Apoptosis

Takada

Aggarwal

2004

The Journal of Immunology

108

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Spleen tyrosine kinase (Syk), a nonreceptor protein kinase initially found to be expressed only in hemopoietic cells, has now been shown to be expressed in nonhemopoietic cells and to mediate signaling of various cytokines. Whether Syk plays any role in TNF signaling was investigated. Treatment of Jurkat T cells with TNF activated Syk kinase but not ZAP70, another member of Syk kinase family, and the optimum activation occurred at 10 s and with 1 nM TNF. TNF also activated Syk in myeloid and epithelial cells. TNF-induced Syk activation was abolished by piceatannol (Syk-selective inhibitor), which led to the suppression of TNF-induced activation of c- JNK, p38 MAPK, and p44/p42 MAPK. Jurkat cells that did not express Syk (JCaM1, JCaM1/lck) showed lack of TNF-induced Syk, JNK, p38 MAPK, and p44/p42 MAPK activation, as well as TNF-induced IκBα phosphorylation, IκBα degradation, and NF-κB activation. TNF-induced NF-κB activation was enhanced by overexpression of Syk by Syk-cDNA and suppressed when Syk expression was down-regulated by expression of Syk-small interfering RNA (siRNA-Syk). The apoptotic effects of TNF were reduced by up-regulation of NF-κB by Syk-cDNA, and enhanced by down-regulation of NF-κB by siRNA-Syk. Immunoprecipitation of cells with Syk Abs showed TNF-dependent association of Syk with both TNFR1 and TNFR2; this association was enhanced by up-regulation of Syk expression with Syk-cDNA and suppressed by down-regulation of Syk using siRNA-Syk. Overall, our results demonstrate that Syk activation plays an essential role in TNF-induced activation of JNK, p38 MAPK, p44/p42 MAPK, NF-κB, and apoptosis.

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Section: Discussionmentioning

confidence: 75%

Section: Tnf Activates Syk Proteinmentioning

confidence: 99%

See 1 more Smart Citation

TNF Activates Syk Protein Tyrosine Kinase Leading to TNF-Induced MAPK Activation, NF-κB Activation, and Apoptosis

Takada

Aggarwal

2004

The Journal of Immunology

108

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“…The proteins were expressed in E. coli and purified using Ni 2ϩ -agarose chromatography as described (32,33) under nondenaturing conditions. The proteins were used immediately after removing imidazole by dialysis.…”

Section: Delivery Of Proteins Into Neutrophils Usingmentioning

confidence: 99%

Antagonistic Cross-talk between Rac and Cdc42 GTPases Regulates Generation of Reactive Oxygen Species

Diebold

Fowler

et al. 2004

Journal of Biological Chemistry

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Cross-talk between Rho GTPase family members (Rho, Rac, and Cdc42) plays important roles in modulating and coordinating downstream cellular responses resulting from Rho GTPase signaling. The NADPH oxidase of phagocytes and nonphagocytic cells is a Rac GTPaseregulated system that generates reactive oxygen species (ROS) for the purposes of innate immunity and intracellular signaling. We recently demonstrated that NADPH oxidase activation involves sequential interactions between Rac and the flavocytochrome b 558 and p67 phox oxidase components to regulate electron transfer from NADPH to molecular oxygen. Here we identify an antagonistic interaction between Rac and the closely related GTPase Cdc42 at the level of flavocytochrome b 558 that regulates the formation of ROS. Cdc42 is unable to stimulate ROS formation by NADPH oxidase, but Cdc42, like Rac1 and Rac2, was able to specifically bind to flavocytochrome b 558 in vitro. Cdc42 acted as a competitive inhibitor of Rac1-and Rac2-mediated ROS formation in a recombinant cell-free oxidase system. Inhibition was dependent on the Cdc42 insert domain but not the Switch I region. Transient expression of Cdc42Q61L inhibited ROS formation induced by constitutively active Rac1 in an NADPH oxidase-expressing Cos7 cell line. Inhibition of Cdc42 activity by transduction of the Cdc42-binding domain of Wiscott-Aldrich syndrome protein into human neutrophils resulted in an enhanced fMetLeuPhe-induced oxidative response, consistent with inhibitory cross-talk between Rac and Cdc42 in activated neutrophils. We propose here a novel antagonism between Rac and Cdc42 GTPases at the level of the Nox proteins that modulates the generation of ROS used for host defense, cell signaling, and transformation.The process by which cells produce reactive oxygen species (ROS) 1 has gained much interest because of the diverse functions attributed to this class of molecules. In nonphagocytic cells, oxidants affect a variety of cellular processes, including transcription factor activation, proliferation, transformation, and apoptosis. In neutrophils and other phagocytes, oxidants play an important role in cellular innate immune responses. A critical component of the bactericidal activity of phagocytes is the NADPH oxidase, also referred to as "phox" (phagocytic oxidase) (1-3), which generates superoxide anion and, subsequently, a number of other ROS. The phagocyte NADPH oxidase is a multiprotein system whose activity is regulated by the RhoGTPase Rac2 in human cells (4 -6). Electrons are transferred from NADPH to molecular oxygen through the action of an integral membrane flavocytochrome b 558 (cyt b 558 ), composed of subunits gp91 phox and p22 phox . In addition to Rac2, the activity of the NADPH oxidase is regulated by the cytosolic components p47 phox , p67 phox , and p40 phox , which exist as a heterotrimeric complex in the cytosol of unstimulated neutrophils (7). In a separate cytosolic complex are Rac2 (or Rac1 in certain species) and GDP dissociation inhibitor (8). When neutrophils are activate...

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“…In these studies, we transduced dominant-negative Cterminal Pyk2 using an HIV-TAT protein transduction domain (TAT-Pyk2-CT) into mice in vivo. Pyk2-CT acted as a dominant negative in that it blocked the tyrosine phosphorylation of endogenous Pyk2 (18,25,26). We tested the hypothesis that Pyk2 mediates both antigen-induced airway inflammation and AHR to methacholine.…”

mentioning

confidence: 99%

Inhibition of Pyk2 Blocks Airway Inflammation and Hyperresponsiveness in a Mouse Model of Asthma.

Duan

Learoyd

Meliton

et al. 2009

A101. Mouse Models of Allergic Inflammation: Mechanisms

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The objective of this investigation was to determine the role of Pyk2, an intracellular nonreceptor protein tyrosine kinase for postadhesive inflammatory cell migration, on airway inflammation and hyperresponsiveness in immune-sensitized mice. Blockade of Pyk2 was effected by intraperitoneal administration of dominant-negative C-terminal Pyk2 fused to a TAT protein transduction domain (TATPyk2-CT). Ovalbumin challenge elicited infiltration of both eosinophils and lymphocytes into airways, increased mucus-containing epithelial cells, and caused increased airway hyperresponsiveness to methacholine in immune-sensitized mice. Pretreatment with 10 mg/kg TAT-Pyk2-CT intraperitoneally blocked all of these effects and further decreased secretion of Th2 cytokine IL-4, IL-5, and IL-13 into the bronchoalveolar lavage fluid. Intranasal administration of IL-5 caused eosinophil migration into the airway lumen, which was attenuated by systemic pretreatment with TAT-Pyk2-CT. In each paradigm, treatment with control protein TAT-GFP had no blocking effect. We conclude that Pyk2, which is essential for inflammatory cell migration in vitro, regulates airway inflammation, Th2 cytokine secretion, and airway hyperresponsiveness in the ovalbumin-sensitized mice during antigen challenge in vivo.Keywords: eosinophils; Pyk2; inflammation; lung Allergic asthma is characterized by the infiltration of lung tissues by inflammatory cells such as eosinophils, mast cells, and T lymphocytes (1, 2). Several mediators released by these cells cause epithelial damage, leading to airway hyperresponsiveness (AHR) and reversible airway obstruction (3). While the specific role of eosinophils in human asthma remains undefined (4), the ablation of pulmonary eosinophils in ovalbumin (OVA)-sensitized mice (i.e., without concurrent effects on T cell activities) results in a significant decrease in mucus accumulation and abolishes allergen-induced AHR (5). Recently, eosinophils were shown to have an integral role in experimental allergic asthma using two different lines of eosinophil-deficient mice (6, 7). Eosinophils may also have a role airway remodeling (8, 9) and development of AHR (10-12). The adhesion molecules involved in the ligation of eosinophils and endothelial cells (13), chemotactic stimuli for eosinophil recruitment (14, 15), and factors regulating eosinophil survival (16, 17) have been characterized previously. However, the intracellular signal transduction pathways triggered by adhesion receptors and cytokines and chemokines affecting eosinophil migration are less well understood. We have found previously that Pyk2 is not involved in integrinmediated eosinophil adhesion, the first stage of cell migration. However, b2 integrin adhesion of eosinophils up-regulates Pyk2 activity, and Pyk2 inhibition blocks eosinophil chemotaxis to IL-5 or fMLP in vitro (18). The objective of this investigation was to determine the role of Pyk2 in eosinophil migration in immune-sensitized mice in vivo.Pyk2 is a member of the focal adhesion kinase (FAK) family that ...

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Critical Role of the Carboxyl Terminus of Proline-rich Tyrosine Kinase (Pyk2) in the Activation of Human Neutrophils by Tumor Necrosis Factor

Cited by 53 publications

References 76 publications

TNF Activates Syk Protein Tyrosine Kinase Leading to TNF-Induced MAPK Activation, NF-κB Activation, and Apoptosis

TNF Activates Syk Protein Tyrosine Kinase Leading to TNF-Induced MAPK Activation, NF-κB Activation, and Apoptosis

Antagonistic Cross-talk between Rac and Cdc42 GTPases Regulates Generation of Reactive Oxygen Species

Inhibition of Pyk2 Blocks Airway Inflammation and Hyperresponsiveness in a Mouse Model of Asthma.

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