Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.13 (protein kinase C)
 49,245 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interferon-gamma (IFN-gamma) induced intercellular adhesion molecule-1 (ICAM-1) expression in human NCI-H292 epithelial cells, as shown by enzyme-linked immunosorbent assay and immunofluorescence staining. The enhanced ICAM-1 expression resulted in increased adhesion of U937 cells to NCI-H292 cells. Tyrosine kinase inhibitors (genistein or herbimycin), Src family inhibitor (PP2), or a phosphatidylinositol-phospholipase C inhibitor (U73122) attenuated the IFN-gamma-induced ICAM-1 expression. Protein kinase C (PKC) inhibitors (staurosporine or Ro 31-8220) also inhibited IFN-gamma-induced response. 12-O-Tetradecanoylphorbol-13-acetate (TPA), a PKC activator, stimulated ICAM-1 expression; this effect was inhibited by tyrosine kinase or Src inhibitor. ICAM-1 promoter activity was enhanced by IFN-gamma and TPA in cells transfected with pIC339-Luc, containing the downstream NF-kappaB and gamma-activated site (GAS) sites, but not in cells transfected with GAS-deletion mutant, pIC135 (DeltaAP2). Electrophoretic gel mobility shift assay demonstrated that GAS-binding complexes in IFN-gamma-stimulated cells contained STAT1alpha. The IFN-gamma-induced ICAM-1 promoter activity was inhibited by tyrosine kinase inhibitors, a phosphatidylinositol-phospholipase C inhibitor, or PKC inhibitors, and the TPA-induced ICAM-1 promoter activity was also inhibited by tyrosine kinase inhibitors. Cotransfection with a PLC-gamma2 mutant inhibited IFN-gamma- but not TPA-induced ICAM-1 promoter activity. However, cotransfection with dominant negative mutants of PKCalpha or c-Src inhibited both IFN-gamma- and TPA-induced ICAM-1 promoter activity. The ICAM-1 promoter activity was stimulated by cotransfection with wild type PLC-gamma2, PKCalpha, c-Src, JAK1, or STAT1. An immunocomplex kinase assay showed that both IFN-gamma and TPA activated c-Src and Lyn activities and that these effects were inhibited by staurosporine and herbimycin. Thus, in NCI-H292 epithelial cells, IFN-gamma activates PLC-gamma2 via an upstream tyrosine kinase to induce activation of PKC-alpha and c-Src or Lyn, resulting in activation of STAT1alpha, and GAS in the ICAM-1 promoter, followed by initiation of ICAM-1 expression and monocyte adhesion.
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PMID:Interferon-gamma-induced epithelial ICAM-1 expression and monocyte adhesion. Involvement of protein kinase C-dependent c-Src tyrosine kinase activation pathway. 1175 11

The receptor tyrosine kinase Tie-1 is expressed predominantly in endothelial cells where it physically associates with the related receptor Tie-2. Positive signalling through Tie-2 is associated with microvessel stability and suppression of this signal is thought to be required for vascular endothelial growth factor (VEGF)-induced microvessel remodelling or growth. Here we examine the effects of VEGF on Tie-1 and the Tie-2:Tie-1 complex. We show that VEGF induces generation of the Tie-1 endodomain and loss of the full-length receptor. The effects of VEGF on endodomain formation are not suppressed by inhibitors of protein kinase C and do not involve the nitric oxide signalling pathway. Tyrosine kinase inhibitors, in contrast, do abolish endodomain generation in response to the endothelial growth factor. VEGF stimulation of cells does not cause dissociation of the Tie-2:Tie-1 complex; rather the complex is converted to a form comprising the full-length-Tie-2 and Tie-1 endodomain. VEGF can therefore switch the Tie-2:Tie-1 complex between two different forms in endothelial cells. The ability of VEGF to modulate Tie-1 and the Tie-2:Tie-1 complex provides a mechanism whereby this initiator of vessel growth and remodelling can directly modulate receptors involved in vessel stabilization. Such cross-talk is likely to be important in the coordinate control of blood vessel formation during development and in postnatal angiogenesis.
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PMID:Vascular endothelial growth factor modulates the Tie-2:Tie-1 receptor complex. 1186 38

The present study using immunoblot showed that corticosterone (B) could induce a rapid activation of p38 in PC12 cells. The dose and time response curves w ere bell shaped with a maximal activation at 10-9 mol/L and 15 min respectively. The activation was not affected by steroid nuclear receptor antagonist RU38486. Bovine serum albumin coupled B (B-BSA) could induce phosphorylation of p38. Tyrosine kinase inhibitor genistein failed to block the phosphorylation, a fact suggesting that the tyrosine kinase activity is not involved in the pathway. On the other hand, phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, could mimic the actions of B, while G 6976, a PKC inhibitor, could completely abolish the phosphorylation induced by B. These results clearly demonstrate that B activates p38 MAPK readily via a putative membrane receptor through a PKC-dependent pathway.
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PMID:Rapid activation of p38 mitogen-activated protein kinase by corticosterone in PC12 cells. 1193 Feb 17

Adenylyl cyclase (AC) superactivation is thought to play an important role in opioid tolerance, dependence, and withdrawal. In the present study, we investigated the involvement of protein kinases in chronic delta-opioid agonist-mediated AC superactivation in Chinese hamster ovary (CHO) cells stably expressing the human delta-opioid receptor (hDOR/CHO). Maximal forskolin-stimulated cAMP formation in hDOR/CHO cells increased by 472 +/- 91, 399 +/- 2, and 433 +/- 73% after chronic treatment with the delta-opioid agonists (+)-4-[(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxy-benzyl]-N,N-diethyl benzamide (SNC 80), [d-Pen2,d-Pen5]-enkephalin, and deltorphin II, respectively. Concurrently, chronic SNC 80 (1 micro M, 4-h) treatment augmented 32P incorporation into a 200-kDa protein immunoreactive with the ACV/VI antibody by 300 +/- 60% in hDOR/CHO cell lysates. The calmodulin antagonist calmidazolium significantly attenuated chronic deltorphin II-mediated AC superactivation. Tyrosine kinase (genistein) and protein kinase C (chelerythrine) inhibitors individually had minimal effect on chronic delta-opioid agonist-mediated AC superactivation. Conversely, simultaneous treatment with both genistein and chelerythrine significantly attenuated AC superactivation. Because we showed previously that the Raf-1 inhibitor 3-(3,5-dibromo-4-hydroxybenzylidene-5-iodo-1,3-dihydro-indol-2-one (GW5074) attenuates AC superactivation, we hypothesize that parallel calmidazolium-, chelerythrine-, and genistein-sensitive pathways converge at Raf-1 to mediate AC superactivation by phosphorylating AC VI in hDOR/CHO cells.
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PMID:Converging protein kinase pathways mediate adenylyl cyclase superactivation upon chronic delta-opioid agonist treatment. 1266 Mar 10

The sequestration of neutrophils in the lung and the release of proinflammatory mediators, including neutrophil elastase, are responsible for sepsis-induced microvascular permeability and alveolar epithelial cell damage. To assess the underlying mechanism, human neutrophil elastase (0.01-0.5 microg/ml) was added to cultured A549 epithelial cells in the presence or absence of inhibitors. IL-8 was analyzed by ELISA or by RT-PCR to measure the IL-8 synthesis capacity. Mitogen-activated protein kinase (MAPK) activity was detected by Western blot analysis. Neutrophil elastase dose-dependently increased IL-8 release from cultured A549 epithelial cells. Pretreatment with a specific elastase inhibitor, elastase inhibitor II (at 0.5, 5, and 50 microg/ml), dose-dependently inhibited neutrophil elastase-induced IL-8 release. The activities of MAPK, p38, and extracellular signal-regulated kinase (ERK) were upregulated by neutrophil elastase. Nuclear transcriptional factor-kappa B (NF-kappaB) and activator protein 1 (AP-1) were also activated. These responses were significantly inhibited by elastase inhibitor II. A specific inhibitor of p38 MAPK (SB203580) and an NF-kappaB inhibitor (pyrrolidine dithiocarbamate), but not an ERK inhibitor (PD 98059), significantly inhibited neutrophil elastase-induced IL-8 release and mRNA expression. The specific tyrosine kinase inhibitor, genistein, and the protein kinase C (PKC) inhibitor, Ro 31-8220, also inhibited IL-8 release and mRNA expression as well as p38 and NF-kappaB activation. There was no significant effect by the protein kinase A inhibitor, H-89, on neutrophil elastase-induced IL-8 synthesis or p38 MAPK activation. Our results indicate that neutrophil elastase activates p38 MAPK which upregulates NF-kappaB and AP-1 activities, thus inducing IL-8 mRNA expression and protein synthesis. Tyrosine kinase and PKC are implicated in neutrophil elastase activation of the MAPK pathway.
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PMID:Neutrophil elastase induces IL-8 synthesis by lung epithelial cells via the mitogen-activated protein kinase pathway. 1473 Feb 9

This study was to determine the mechanism of tumor necrosis factor-alpha (TNF-alpha)-enhanced cyclooxygenase (COX)-2 expression associated with prostaglandin E2 (PGE2) synthesis in human tracheal smooth muscle cells (HTSMCs). TNF-alpha markedly increased COX-2 expression and PGE2 synthesis in a time- and concentration-dependent manner, whereas COX-1 remained unaltered. Tyrosine kinase inhibitor (genistein), phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor (D-609) and PKC inhibitor (GF109203X) attenuated TNF-alpha-induced COX-2 expression and PGE2 synthesis in HTSMCs. TNF-alpha-induced COX-2 expression and PGE2 synthesis were also inhibited by PD98059 (an inhibitor of MEK1/2) and SB203580 and SB202190 (inhibitors of p38 MAPK), respectively, suggesting the involvement of p42/p44 and p38 MAPKs in these responses. This hypothesis was further supported by that TNF-alpha induced a transient activation of p42/p44 and p38 MAPKs in a time-and concentration-dependent manner. Furthermore, TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) reversely correlated with the degradation of IkappaB-alpha in HTSMCs. TNF-alpha-induced COX-2 expression and PGE2 synthesis was also inhibited by NF-kappaB inhibitor pyrrolidinedithiocarbamate (PDTC). These findings suggest that the increased expression of COX-2 correlates with the release of PGE2 from TNF-alpha-challenged HTSMCs, at least in part, mediated through p42/p44 and p38 MAPKs as well as NF-kappaB signaling pathways in HTSMCs.
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PMID:Tumor necrosis factor-alpha-induced cyclooxygenase-2 expression in human tracheal smooth muscle cells: involvement of p42/p44 and p38 mitogen-activated protein kinases and nuclear factor-kappaB. 1475 45

Various kinases, such as tyrosine, protein kinase C (PKC) and MAP kinase, play important role in the cellular response to radiation, but little is known about the specific response in the whole animal. Most studies, except a few, are based on single cells. There is a paucity of data where signaling following whole body irradiation is concerned. In this study a comparison has been made between the activities of these kinases following ex vivo and in vivo irradiation. Tyrosine kinase activity showed no difference in the lymphocytes irradiated ex vivo or in vivo. A significant differential dose-dependent response could be observed in PKC activity. PKC was seen to be activated at the higher dose, i.e., 1 Gy in, in vivo irradiated lymphocytes, whereas in ex vivo irradiated lymphocytes, PKC was seen to be activated at the lower dose, i.e., 0.1 Gy. MAP kinase activity was seen to decrease with an increasing dose in ex vivo irradiated lymphocytes. In vivo MAP kinase activity was seen to increase as the dose increased, with maximum activation at 3 Gy. These kinases are being used to manipulate the tumor response to radiotherapy. Thus it is essential to study the behavior of the above kinases in the whole animal because the difference in response of a single cell to the whole animal may be different.
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PMID:Differential activation of kinases in ex vivo and in vivo irradiated mice lymphocytes. 1513

We previously demonstrated that lipoteichoic acid (LTA) might activate phosphatidylcholine-phospholipase C (PC-PLC) and phosphatidylinositol-phospholipase C (PI-PLC) to induce protein kinase C activation, which in turn initiates nuclear factor-kappaB (NF-kappaB) activation and finally induces inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) release in RAW 264.7 macrophages. In this study, we further investigated the roles of tyrosine kinase, phosphatidylinositiol 3-kinase (PI3K)/Akt, and p38 mitogen-activated protein kinase (MAPK) in LTA-induced iNOS expression and NO release in RAW 264.7 macrophages. Tyrosine kinase inhibitors (genistein and tyrphostin AG126), PI3K inhibitors (wortmannin and LY 294002), and a p38 MAPK inhibitor (SB 203580) attenuated LTA-induced iNOS expression and NO release in concentration-dependent manners. Treatment of RAW 264.7 macrophages with LTA caused time-dependent activations of Akt and p38 MAPK. The LTA-induced Akt activation was inhibited by wortmannin, LY 294002, genistein, and tyrphostin AG126. The LTA-induced p38 MAPK activation was inhibited by genistein, tyrphostin AG126, wortmannin, LY 294002, and SB 203580. The LTA-induced formation of an NF-kappaB-specific DNA-protein complex in the nucleus was inhibited by wortmannin, LY 294002, genistein, tyrphostin AG126, and SB 203580. Treatment of macrophages with LTA caused an increase in kappaB-luciferase activity, and this effect was inhibited by tyrphostin AG126, wortmannin, LY 294002, the Akt dominant negative mutant (AktDN), and SB 203580. Based on those findings, we suggest that LTA might activate the PI3K/Akt pathway through tyrosine kinase to induce p38 MAPK activation, which in turn initiates NF-kappaB activation, and ultimately induces iNOS expression and NO release in RAW 264.7 macrophages.
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PMID:Lipoteichoic acid induces nuclear factor-kappaB activation and nitric oxide synthase expression via phosphatidylinositol 3-kinase, Akt, and p38 MAPK in RAW 264.7 macrophages. 1594 54

Recent studies demonstrate that reactive oxygen species (ROS) are important mediators of acute pancreatitis, whether induced experimentally or in necrotizing pancreatitis in humans; however, the cellular processes involved remain unclear. Adapter protein CrkII, plays a central role for convergence of cellular signals from different stimuli. Cholecystokinin (CCK), which induces pancreatitis, stimulates CrkII tyrosine phosphorylation and CrkII protein complexes, raising the possibility it can be important in the acinar cell responses to ROS. Therefore, our aim was to investigate whether CrkII signaling is involved in the biological response of rat pancreatic acini to H2O2 and the intracellular mediators implicated. Treatment of isolated rat pancreatic acini with H2O2 rapidly stimulates CrkII phosphorylation, measured as electrophoretic mobility shift and by using a phosphospecific antibody (pTyr221). Tyrosine kinase blocker B44 inhibits the higher phosphorylation state, demonstrating that it occurs mainly in tyrosine residues. H2O2-induced CrkII phosphorylation is time- and concentration-dependent, showing maximal effect with 3 mM H2O2 at 5 min. The intracellular pathways induced by H2O2 leading to CrkII tyrosine phosphorylation do not involve PKC, intracellular calcium, PI3-K or the actin cytoskeleton integrity. ROS generation clearly promotes the formation of protein complex CrkII-PYK2. In conclusion, ROS clearly affect the key adapter protein CrkII signaling by two ways: stimulation of CkII phosphorylation and a functional consequence: formation of CrkII-protein complexes. Because of its central role in activating more distal pathways, CrkII might likely play an important role in the ability of ROS to induce pancreatic cellular injury and pancreatitis.
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PMID:Adapter protein CRKII signaling is involved in the rat pancreatic acini response to reactive oxygen species. 1618

Epidermal growth factor (EGF) is predominantly secreted by salivary glands and activates Na(+)/H(+) exchanger-1 (NHE-1), which regulates intracellular pH (pH(i)). We investigated the roles of EGF and NHE-1 in esophageal epithelial defense against acid using human esophageal epithelial cell lines and a rat chronic esophagitis model. Esophageal epithelial cells were incubated with acidified medium in the absence or presence of EGF. Cell viability and changes in pH(i) were measured. Chronic acid reflux esophagitis was induced in rats with and without sialoadenectomy. Esophageal lesion index, epithelial proliferation, and expression of EGF receptors and NHE-1 were examined. EGF protected esophageal epithelial cells against acid in a dose-dependent manner, and the cytoprotective effect of EGF was completely blocked by treatment with NHE-1 inhibitors. Tyrosine kinase, calmodulin, and PKC inhibitors significantly inhibited cytoprotection by EGF, whereas MEK, phosphatidylinositol 3-kinase, and PKA inhibitors had no effect. EGF significantly increased pH(i) recovery after NH(4)Cl pulse acidification, and this increase in pH(i) recovery was significantly blocked by inhibitors of calmodulin and PKC. Sialoadenectomy led to an increase in the severity of chronic esophagitis but affected neither epithelial proliferation nor expression of EGF receptors. Expression of NHE-1 mRNA was increased in esophagitis and upregulated in rats with sialoadenectomy. The increasing severity of esophagitis in rats with sialoadenectomy was prevented by exogenous administration of EGF. In conclusion, EGF protects esophageal epithelial cells against acid through NHE activation via Ca(2+)/calmodulin and the PKC pathway. Deficiency in endogenous EGF is associated with increased severity of esophagitis. EGF and NHE-1 play crucial roles in esophageal epithelial defense against acid.
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PMID:Roles of epidermal growth factor and Na+/H+ exchanger-1 in esophageal epithelial defense against acid-induced injury. 1630 34


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