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)

Incubation of human umbilical vein endothelial cells with one of the following compounds: endotoxin, recombinant interleukin-1 beta, recombinant tumor necrosis factor alpha, allogenic lymphocyte subpopulations or phorbol ester resulted in significant induction of tissue factor synthesis. Diacylglycerol had the same effect and also enhanced synergistically the induction caused by endotoxin and interleukin-1 beta. Two different inhibitors of protein kinase C, H7 and sphingosine, inhibited tissue factor synthesis at concentrations which did not depress protein synthesis in general, suggesting that protein kinase C is involved in the processes leading to tissue factor synthesis. Cells down-regulated for the tissue factor response to TPA responded essentially normally to endotoxin and interleukin-1 with regard to tissue factor synthesis.
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PMID:Induction of tissue factor synthesis in human umbilical vein endothelial cells involves protein kinase C. 163 96

Tissue factor (TF) is an integral membrane glycoprotein that serves as a cellular receptor and cofactor for the activation of the plasma protease factor VII. TF activity in both monocytes and endothelial cells is regulated by various cytokines and mitogens, including the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA). Three TF constructs (full-length human, a cytoplasmic domain deletion mutant, and a human-rat TF chimera), expressed in a human kidney cell line, were used to examine the in vivo phosphorylation state of TF after PMA treatment. The cytoplasmic domains of both rat and human TF were rapidly phosphorylated after cells were treated with 10-100 nM PMA. This response was completely abolished by preincubating cells with staurosporine, the potent PKC inhibitor, prior to PMA treatment. Localization of the phosphorylation site(s) to the cytoplasmic domain was demonstrated using a deletion mutant of TF and by CNBr digestion at the single methionine residue (Met-210) in the TF sequence. The rat TF cytoplasmic domain was phosphorylated to a higher specific activity than the human TF cytoplasmic domain. Phosphoamino acid analysis of the chimeric TF revealed both phosphothreonine and phosphoserine, whereas human TF contained only phosphoserine. Thus both potential phosphoacceptor sites are phosphorylated in the rat TF cytoplasmic domain. Alignment of TF cDNA sequences of mouse, rat, rabbit, and man revealed that the phosphoacceptor site (X-S*/T*-P-X, where asterisk indicates the phosphorylated residue) in the cytoplasmic domain has been conserved through evolution.
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PMID:The cytoplasmic domain of tissue factor is phosphorylated by a protein kinase C-dependent mechanism. 174 Apr 9

The induction of pulmonary alveolar macrophage (PAM) tissue factor-dependent procoagulant activity is central to the deposition of inflammatory fibrin in the pulmonary alveolus. The presence of enhanced tissue factor activity is often associated with pulmonary fibrin deposition, an important pathogenetic event that can delay resolution of pulmonary inflammation and promote the induction of pulmonary fibrosis. Since tissue factor synthesis induction and activation pathways are potential therapeutic targets for modulation of alveolar macrophage tissue factor (procoagulant) activity, we examined the pathways through which endotoxin lipopolysaccharide (LPS) induces bovine PAM tissue factor-dependent procoagulant activity. PAM procoagulant activity was markedly enhanced to 10 times the levels of freshly isolated PAM after 8 h of culture in the presence of either the protein kinase C (PKC) agonist phorbol 12-myristate 13-acetate (PMA) or LPS. Both LPS-(P less than 0.002) and PMA-induced activity (P less than 0.007) was completely ablated by the PKC inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H 7,100 microM) but was unaffected by the cyclic nucleotide-dependent protein kinase inhibitor N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA-1004, 100 microM). The arachidonate cyclooxygenase pathway inhibitor phenylbutazone (10(-4) M) had modest effects that were not statistically significant. The unstimulated increase of procoagulant activity in 8-h cultures was unaffected by the same inhibitory modulations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Endotoxin-mediated bovine alveolar macrophage procoagulant induction is dependent on protein kinase C activation. 209 May 87

The procoagulant response of endothelium to many stimuli alters the expression of tissue factor, thrombomodulin, and plasminogen activator inhibitors (PAI) PAI-1 and PAI-2. The regulation of these proteins was examined in cultured human endothelial cells treated with phorbol myristate acetate (PMA) or tumor necrosis factor (TNF). Unstimulated cells contained approximately 670 PAI-1 and approximately 100 thrombomodulin mRNA molecules/cell, whereas tissue factor and PAI-2 mRNAs were not detectable. By 3-5 h, PMA or TNF induced both tissue factor and PAI-2 to approximately 150-420 mRNA molecules/cell and both mRNAs declined to basal levels within several hours; however, PAI-1 and thrombomodulin mRNA levels did not change. Nuclear runoff assays showed that PMA, TNF, or cycloheximide induced transcription of the tissue factor gene, whereas the genes for thrombomodulin, PAI-1, and PAI-2 apparently were transcribed at the same relative rate in the presence or absence of these agents. Treatment of cells with cycloheximide stabilized tissue factor and PAI-2 mRNAs and increased their induction by PMA or TNF. The synthesis of tissue factor, PAI-1, and PAI-2 proteins paralleled their mRNA levels. The effects of TNF were similar to those of PMA with one exception. In contrast to PMA, TNF reduced thrombomodulin activity approximately 80% with no change in thrombomodulin mRNA levels. Thus, PAI-2 may be induced by inhibiting mRNA degradation. Tissue factor can be induced by stimulating transcription and potentially by inhibiting mRNA degradation. Thrombomodulin can be repressed by a translational or posttranslational mechanism. PAI-1 was not regulated under the conditions studied. The different effects of PMA and TNF on thrombomodulin expression indicate that some effects of TNF are not mediated solely by protein kinase C.
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PMID:Regulation of endothelial cell coagulant properties. Modulation of tissue factor, plasminogen activator inhibitors, and thrombomodulin by phorbol 12-myristate 13-acetate and tumor necrosis factor. 255 68

The monocyte is the only normal circulating cell type capable of initiating blood coagulation through the expression of tissue factor. Recently isolated peripheral blood monocytes that contain no demonstrable tissue factor activity can be induced to express tissue factor activity by a number of stimulatory agents. Monocyte-associated tissue factor activity transiently increases in response to adherence to tissue culture plates and, consistent with other reports, markedly increases after the isolated monocytes are treated with endotoxin. Phorbol myristate acetate (PMA) induced an increase in tissue factor activity at low doses (10(-11) to 10(-12) mol/L). Conversely, concentrations of PMA that stimulate release of oxygen metabolites or that cause the cytosol-to-membrane translocation of protein kinase C (PKC) (10(-9) to 10(-7) mol/L) resulted in a rapid decrease in both adherence-induced and endotoxin-induced monocyte tissue factor activity. The effects of PMA on monocytes were time- and dose-dependent with respect to PKC translocation, release of oxygen metabolites, and changes in tissue factor activity. Immunofluorescent staining of monocytes with monoclonal antibody (MoAb) HTF1-7B8, directed against human tissue factor, revealed that tissue factor antigen was induced concurrently with tissue factor activity by adherence and endotoxin and that tissue factor antigen decreased after PMA stimulation.
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PMID:Monocyte-associated tissue factor is suppressed by phorbol myristate acetate. 284 Sep 84

The procoagulant response of endothelium to pathophysiological agents such as tumour necrosis factor alpha (TNF alpha) and phorbol myristate acetate (PMA) alters the expression of proteins such as tissue factor. The modulation of such procoagulant activity (PCA) by the polyunsaturated fatty acid arachidonic acid (20:4,n-6) and its 15-hydroperoxy (15-HPETE) and 15-hydroxy (15-HETE) metabolites was examined since this may have important implications in cardiovascular disease and atherosclerosis. Treatment of human umbilical vein endothelial cells (HUVEC) for 30 min with 20:4, 15-HPETE or 15-HETE before induction of PCA with TNF alpha (100 U) or PMA (10(-7) M) caused a significant inhibition of PCA. This inhibition was seen at 2-5 microM fatty acids. Dose response curves with TNF alpha indicated that the inhibition was greatest at higher concentrations of TNF alpha (> or = 250U TNF alpha/ml). The mode of administration of the fatty acid was not critical as fatty acids presented as DPC-fatty acid micelles or solubilised in ethanol gave similar inhibitions of PCA. 20:4, 15-HPETE or 15-HETE did not alter the binding of I125-labelled TNF alpha to its surface receptors on HUVEC, suggesting that the effect of these fatty acids was not mediated by events at the cell surface receptor level. In support of this, these fatty acids were found to inhibit PCA induced by PMA which bypasses cell surface receptors to activate protein kinase C directly.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inhibitory effects of arachidonic acid (20:4,n-6) and its monohydroperoxy- and hydroxy-metabolites on procoagulant activity in endothelial cells. 748 27

Tissue factor (TF) is a transmembrane receptor which, in association with factors VII and VIIa, activates factor IX and X, thereby activating the coagulation protease cascades. In response to bacterial lipopolysaccharide (LPS) monocytes transcribe, synthesize and express TF on their surface. We investigated whether LPS-induced TF in human monocytes is mediated by protein kinase C (PKC) activation. The PKC agonists phorbol 12-myristate 13-acetate (PMA) and phorbol 12, 13 dibutyrate (PdBu) were both potent inducers of TF in human monocytes, whereas 4 alpha-12, 13 didecanoate (4 alpha-Pdd) had no such effect. Both LPS- and PMA-induced TF activity were inhibited, in a concentration dependent manner, by three different PKC inhibitors: H7, staurosporine and calphostin C. TF antigen determination confirmed that LPS-induced cell-surface TF protein levels decreased in parallel to TF functional activity under staurosporine treatment. Moreover, Northern blot analysis of total RNA from LPS- or PMA-stimulated monocytes showed a concentration-dependent decrease in TF mRNA levels in response to H7 and staurosporine. The decay rate of LPS-induced TF mRNA evaluated after the arrest of transcription by actinomycin D was not affected by the addition of staurosporine, suggesting that its inhibitory effect occurred at a transcriptional level. We conclude that LPS-induced production of TF and its mRNA by human monocytes are dependent on PKC activation.
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PMID:Endotoxin-induced tissue factor in human monocytes is dependent upon protein kinase C activation. 1101 86

Inflammatory agents including bacterial endotoxin (LPS) and low concentrations of phorbol myristate acetate (PMA) stimulate human peripheral blood monocytes to transiently express tissue factor procoagulant activity. Concentrations of PMA that cause the cytosol-to-membrane translocation of protein kinase C (PKC) (10(-9)-10(-7) M) induce a rapid decrease in monocyte tissue factor activity. Staurosporine, an inhibitor of protein kinase C, enhances the stimulatory effect of low concentrations of PMA on monocyte expression of tissue factor activity and blocks suppression of tissue factor activity at high PMA concentrations. Furthermore, staurosporine prolongs LPS-induced tissue factor expression in monocytes. These results suggest that protein kinases modulate tissue factor activity in human monocytes by regulating both induction and down-regulation.
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PMID:Staurosporine blocks down-regulation of monocyte-associated tissue factor. 753 87

The monocyte is the only circulating cell type capable of initiating blood coagulation by the expression of tissue factor (TF). The mechanism and kinetics of TF mRNA and TF activity induction in human peripheral blood monocytes (HPBM) in response to bacterial lipopolysaccharide (LPS) and phorbol myristate acetate (PMA) were investigated. Northern blot analysis showed that both LPS and PMA induce a transient accumulation of TF mRNA in HPBM, that reaches maximum levels after 3-6 h and rapidly declines thereafter. Nuclear run-on experiments demonstrated that the accumulation of TF mRNA requires de novo transcription of the TF gene. Since cycloheximide alone also caused an increase of TF mRNA levels and gene transcription it is concluded that the transcriptional activation of the TF gene does not require protein synthesis. Using specific protein kinase inhibitors, it was further demonstrated that activation of the protein kinase C pathway is involved in the induction of TF mRNA in HPBM. The accumulation of TF mRNA in LPS-stimulated HPBM is followed by an increase of TF activity on the cell surface. The kinetics of TF mRNA induction were found to be very similar in HPBM stimulated with LPS or PMA. However, in the latter case TF activity appeared considerably later on the cell membrane than in the LPS-stimulated cells. Non-stimulated HPBM contain very low levels of mRNA of the tissue factor pathway inhibitor (TFPI). No induction of TFPI (mRNA, activity or antigen) in HPBM after LPS or PMA treatment was demonstrated. This seems to be in contrast with the earlier observation that the human monocyte cell line U937 produces significant amounts of TFPI in response to treatment with LPS and PMA.
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PMID:Expression of tissue factor and tissue factor pathway inhibitor in monocytes in response to bacterial lipopolysaccharide and phorbolester. 805 53

Increased procoagulant activity of vascular endothelial cells may be an important component in the pathogenesis of intravascular coagulation associated with gram-negative bacterial diseases. Two bovine endothelial cell (BEC) lines isolated from pulmonary arteries (ENS-2 and ENT-18) were used in this study to investigate procoagulant signal transduction pathways of endotoxin (lipopolysaccharide, LPS)--stimulated BECs. The endothelial cell line ENS-2 was sensitive to LPS as demonstrated by tissue factor (TF) expression, but in contrast, the ENT-18 endothelial cell line was unusually resistant to the effects of LPS. No remarkable quantitative difference in binding of radiolabeled LPS was detected between the two endothelial cell lines. A protein kinase C (PKC) activator (phorbol 12-myristate 13-acetate, PMA) failed to induce TF expression in either cell line at concentrations ranging from 0.05 to 1.00 microM when used as a sole stimulus for the endothelial cells. However, when PMA was used in combination with LPS, PMA enhanced the stimulatory effect of LPS on the endothelial cells. In parallel experiments, PKC inhibitors (H-7 and GF 109203X) interfered with the stimulatory effect of LPS on the cells by decreasing tissue factor expression. We also found that an activator of adenylate cyclase, forskolin, similarly inhibited LPS-induced tissue factor activity. In contrast, protein tyrosine kinase inhibitors (genistein, lavendustin A) had no inhibitory effect on LPS-induced endothelial cell tissue factor expression. Our results collectively suggest that activation of PKC is an important step in stimulation of endothelial cells by LPS, and that LPS and phorbol esters may synergize to produce an enhanced stimulatory effect. Our results also suggest participation of cAMP in controlling LPS-mediated stimulation of endothelial cells, but fail to demonstrate a role for protein tyrosine kinase activity.
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PMID:Signal transduction pathways of bacterial lipopolysaccharide-stimulated bovine vascular endothelial cells. 807 Sep 6


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