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

We recently showed that recombinant human granulocyte-colony stimulating factor (rhG-CSF) maintained the viability of human neutrophils in incubation for up to 72 hours. However, it is not known whether rhG-CSF can enhance neutrophil survival in in vivo situations. To clarify this issue, we investigated neutrophil survival in vitro following in vivo injection of rhG-CSF. Neutrophils were obtained from 4 pediatric patients with malignancies and healthy adult volunteers before and after rhG-CSF administration. Neutrophils obtained before rhG-CSF treatment started to undergo apoptosis after 24 h of incubation. In contrast, the survival of neutrophils drawn after rhG-CSF administration increased by approximately 24 h. Concomitantly, the appearance of typical ladder-like DNA fragmentation was delayed. Such an increase in neutrophil survival was inhibited by co-incubation with either H 7 (10 mumol/l) or H 8 (20 mumol/l), which worked as protein kinase C inhibitors. Although our study did not measure neutrophil survival in vivo directly, it provides us with further evidence that rhG-CSF may function to prolong neutrophil life expectancy in vivo.
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PMID:In vivo administration of granulocyte colony-stimulating factor promotes neutrophil survival in vitro. 752 81

Stimulation of mast cells, either via the IgE receptor or with calcium ionophore triggers the production of several cytokines, such as interleukins-3, -4, -5, and -6, and GM-CSF. In PB-3c mastocytes, ionophore-induced IL-3 and GM-CSF expression is primarily the result of mRNA stabilization, and is enhanced by oncogenic ras. Apart from mobilizing calcium, the IgE receptor activation leads to production of DAG and elevation of cAMP levels, thereby activating protein kinases C and A, respectively. The influence of these two secondary messengers on cytokine production was examined using the cAMP elevating agent IBMX, the phorbol ester PMA, and the staurosporine derivative CGP 41251, which preferentially inactivates PKC. IBMX was determined to be a potent coinducer of IL-3 expression, whereas elevation of IL-6 and GM-CSF was more pronounced in PMA-treated cells. Both PMA and IBMX were shown to act posttranscriptionally on IL-3, by extending the half-life of the mRNA. Ionophore-induced cytokine expression appears to require serine/threonine kinase activity, as it could be abolished by treatment with the drug CGP 41251. Our results therefore suggest that the factors regulating cytokine expression and mRNA stability are subject to regulation by serine/threonine phosphorylation.
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PMID:Modulation of cytokine expression in PB-3c mastocytes by IBMX and PMA. 752 62

Bryostatins, macrocyclic lactones from the marine bryozoan Bugula neritina, are potent antineoplastic agents and multi-potential stimulators of immune cells. We have examined the effects of bryostatins on mediator release from human basophilic leukocytes and human tissue mast cells. Bryostatins 1, 2, and 5 (10 to 3,000 nmol/L) induced histamine secretion from purified and unpurified peripheral blood basophils, whereas they caused no release of peptide-leukotriene C4 from these cells. The rate of histamine release caused by bryostatin 1 was slower than that caused by anti-IgE (t1/2 +/- SEM = 38.2 +/- 4.7 minutes v 8.9 +/- 0.2 minutes; P < .01), whereas the temperature dependence was similar (optimum release at 37 degrees C, approximately 30% less at 30 degrees C, and no release at 22 degrees C or 4 degrees C). The addition of increasing concentrations of extracellular Ca2+ to the medium caused histamine release in the presence of bryostatins. Subeffective concentrations of bryostatins and anti-IgE produced a synergistic effect on histamine release from basophils. Staurosporine, chelerythrine, and calphostin C (0.1 to 10 nmol/L), which are protein kinase C inhibitors, inhibited the histamine secretion activated by bryostatin 1 and tetradecanoylphorbol-acetate (TPA). Preincubation with granulocyte-monocyte colony-stimulating factor (GM-CSF; 1 and 5 nmol/L) and interleukin-3 (IL-3; 10 ng/mL) potentiated the activation of human basophils induced by bryostatin 1. Neither bryostatin 1 nor bryostatin 2 induced the release of histamine from mast cells isolated from human lung or skin tissues. However, brief (10 minutes) preincubation with bryostatin 1 (3 to 300 nmol/L) potently inhibited the histamine secretion induced by anti-IgE from skin or lung mast cells. Bryostatin 1 was a more potent (by approximately 30 times) inhibitor of IgE-mediated histamine release than was TPA. The heterogeneous effects exerted by bryostatins on human basophils and mast cells can be of interest for those designing therapeutic trials using these agents.
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PMID:The antineoplastic bryostatins affect human basophils and mast cells differently. 753 37

In the present study, we have used a human erythroleukemia cell line, TF-1, that proliferates in response to granulocyte macrophage colony stimulating factor (GM-CSF), interleukin-3 (IL-3), and interleukin-5 (IL-5) to investigate the role of receptors for these cytokines in signal transduction mechanisms involved in proliferative responses. The receptors for GM-CSF, IL-3, and IL-5 each possess a cytokine specific alpha subunit, but all three share a common beta chain. Using an immunoblotting system designed to detect phosphotyrosine containing proteins and a permeabilized cell system to detect rapid changes in phosphate turnover on proteins, we show that while GM-CSF and IL-3 use tyrosine phosphorylation to mediate mitogenic signal transduction, IL-5 uses tyrosine dephosphorylation in its signaling pathway. The use of different signaling pathways by these cytokines can be confirmed in a biologic system whereby the proliferation induced in culture by GM-CSF and IL-3 is inhibited by tyrosine kinase inhibitors, but that induced by IL-5 is enhanced. Conversely, GM-CSF- and IL-3-induced proliferation is stimulated by a tyrosine phosphatase inhibitor, yet IL-5-induced proliferation is inhibited. Inhibitors of protein kinase C inhibit IL-3- and GM-CSF-, but not IL-5-induced proliferation. We suggest that, because all these cytokines share the identical beta chain of their receptors, the cytokine specific alpha chain mediates the linkage of each receptor to the individual biochemical signal transduction pathways responsible for the different biologic activities of these cytokines.
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PMID:Evidence for a signaling role for the alpha chains of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 receptors: divergent signaling pathways between GM-CSF/IL-3 and IL-5. 754 66

Previously, it has been observed that newborn pig pial artery constriction after fluid percussion brain injury was associated with elevated CSF dynorphin and beta endorphin concentration. Additionally, brain injury reversed dynorphin-induced pial artery vasodilation to vasoconstriction. The present study was designed to characterize the relationship between opioids and activation of phospholipase C (PLC) and protein kinase C (PKC) in brain injury-induced pial vasoconstriction. Anesthetized newborn pigs equipped with a closed cranial window were connected to a percussion device consisting of a saline-filled cylindrical reservoir with a metal pendulum. Brain injury of moderate severity (1.9-2.3 atm) was produced by allowing the pendulum to strike a piston on the cylinder. Brain injury decreased pial arteriolar diameter within 10 min of injury and continued to fall progressively for 3 h (130 +/- 5, 108 +/- 4 and 102 +/- 5 microns for 0, 10 and 180 min postinjury). In contrast, the PLC inhibitor, neomycin (10(-4) M), blunted brain injury-induced pial vasoconstriction (133 +/- 4, 129 +/- 4 and 135 +/- 5 microns for 0, 10 and 180 min postinjury, respectively). Similarly, staurosporine (10(-7) M), a PKC inhibitor, also blunted brain injury-induced vasoconstriction. beta endorphin (10(-8), 10(-6) M)-induced pial artery vasoconstriction was blunted by neomycin (12 +/- 1, 19 +/- 1 vs. 2 +/- 1, 4 +/- 2% constriction before and after neomycin, respectively). Staurosporine similarly blunted beta endorphin pial constriction (10 +/- 1, 15 +/- 1 vs. 1 +/- 1, 1 +/- 1% constriction before and after staurosporine, respectively). The constrictor potential for dynorphin was also inhibited by neomycin and staurosporine.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relationship between opioids and activation of phospholipase C and protein kinase C in brain injury induced pial artery vasoconstriction. 758 21

Granulocyte macrophage colony-forming cells (GM-CFC) are bipotential progenitor cells that can proliferate and develop into macrophages in response to macrophage CSF or into neutrophils in response to stem cell factor or granulocyte CSF. These cytokines promoted growth and development in highly enriched GM-CFC. In [3H]thymidine suicide assays, IL-4 was shown to stimulate proliferation of GM-CFC to the same degree as IL-3 and other potent mitogens for GM-CFC. IL-4 also maintained the clonogenic potential of enriched GM-CFC over a 2-day period. However, after several days in the presence of IL-4, the GM-CFC began to die and retained blast cell morphology characteristic of the isolated GM-CFC. When a high concentration of IL-4 was added to GM-CFC with neutrophilic stimuli, the response of these cells was altered because macrophages were formed. This effect was achieved by a 4-h preincubation with IL-4, suggesting that an early signal produced by IL-4 promotes lineage restriction, although IL-4 itself cannot promote development. IL-4, like macrophage CSF, translocates PKC-alpha to the nucleus in GM-CFC, this redistribution of protein kinase C alpha (PKC-alpha) being inhibited by calphostin C (a PKC inhibitor). Calphostin C also blocked IL-4-mediated development of macrophages in stem cell factor- and granulocyte-CSF-treated cells. This is further evidence that PKC-alpha translocation is involved in the commitment of GM-CFC to macrophage development. This data also suggests that agonist-stimulated lineage commitment can be uncoupled from development in normal hematopoietic cells.
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PMID:IL-4 promotes macrophage development by rapidly stimulating lineage restriction of bipotent granulocyte-macrophage colony-forming cells. 760 62

Severe congenital neutropenia (SCN) can be corrected in vivo by treatment with pharmacological dosages of recombinant human granulocyte colony-stimulating factor (rhG-CSF). In order to analyze the decreased chemotaxis of neutrophils from SCN patients receiving rhG-CSF, neutrophil functions essential for chemotaxis were investigated. The mobilization of cytosolic calcium ([Ca2+]i) and the functional state of cytoskeletal proteins in neutrophils from SCN patients were compared with either neutrophils from healthy donors (or, in selected experiments, from patients with cyclic neutropenia) and neutrophils from patients with chemotherapy-induced neutropenia also receiving rhG-CSF. Using flow cytometric analysis, two neutrophil subpopulations were detected in SCN patients in response to N-formylmethionine leucyl-phenylalanine (FMLP) (10(-9) M to 10(-7) M), one of which was unable to respond to this stimulus with an increase in [Ca2+]i. Whereas a homogeneous increase in [Ca2+]i in normal neutrophils occurred at 10(-9) M FMLP, neutrophils from SCN patients required 10(-6) M FMLP to respond homogeneously with an increase in [Ca2+]i. In contrast, G-CSF induced neutrophils from patients with cyclic neutropenia and from patients with chemotherapy-induced neutropenia showed a normal increase in [Ca2+]i after stimulation. The [Ca2+]i-dependent superoxide anion (O2-) generation in response to FMLP was also significantly diminished in neutrophils from SCN patients compared to normal neutrophils. However, O2- generation elicited by phorbolester (PMA), which directly activates protein kinase C (PKC), was not affected in SCN neutrophils. The total immunoreactive actin content and basal F-actin content in neutrophils from SCN patients were elevated as compared to normal neutrophils and neutrophils from patients with chemotherapy-induced neutropenia. The increase in F-actin content following FMLP activation was much lower in neutrophils from SCN patients as compared with normal neutrophils. These data suggest a defect in the signal transduction pathway in neutrophils from SCN patients between FMLP ligand-receptor interaction and Ca2+ mobilization, whereas upstream of PKC, triggered events seem to be unaffected. Therefore, [Ca2+]i-dependent neutrophil function in response to FMLP, such as actin disassembly, chemotaxis and O2- generation are diminished in SCN neutrophils. The pathomechanism responsible for the defective [Ca2+]i increase might be an initial step in understanding the underlying pathophysiology of SCN.
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PMID:Abnormal regulation in the signal transduction in neutrophils from patients with severe congenital neutropenia: relation of impaired mobilization of cytosolic free calcium to altered chemotaxis, superoxide anion generation and F-actin content. 767 87

We have examined the effect of the macrocyclic lactone protein kinase C (PK-C) activator bryostatin 1 on the proliferative capacity and lineage commitment of CD34+ human bone marrow cells exposed to the granulocyte-macrophage colony-stimulating factor/interleukin-3 (GM-CSF/IL-3) fusion protein pIXY 321. pIXY 321 administered at a dose of 10 ng/mL was as effective as the combination of plateau concentrations of recombinant (r) IL-3 and rGM-CSF (e.g., 50 ng/mL) in stimulating the growth of day-14 committed myeloid progenitors (colony-forming units granulocyte/macrophage [CFU-GM]). In the large majority of samples tested, coadministration of 0.5 to 100 nM bryostatin 1 with either pIXY 321 or the combination of rIL-3 plus rGM-CSF led to modest but significant increases (e.g., 30 to 75%) in the number of CFU-GM, compared to administration of growth factors alone. The degree of bryostatin 1-induced potentiation, however, was considerably less than that previously observed in the case of cells exposed to either rIL-3 or rGM-CSF, where increases of 100 to 150% were regularly noted. While at least 50% of day-14 CFU-GM stimulated by either pIXY 321 or the combination of rIL-3 plus rGM-CSF were of the pure or mixed eosinophilic variety, coadministration of bryostatin 1 resulted in a dramatic inhibition of eosinophilic colonies and a corresponding increase in pure and mixed neutrophil and macrophage colonies. Although coadministration of recombinant granulocyte colony-stimulating factor (rG-CSF) or recombinant colony-stimulating factor-1 (rCSF-1) mimicked the capacity of bryostatin 1 to increase the total number of pIXY 321-induced day-14 CFU-GM, these growth factors, unlike bryostatin 1, were not capable of inhibiting eosinophilic colony formation. Furthermore, whereas addition of neutralizing antibodies to G-CSF or CSF-1 blocked the capacity of these growth factors to potentiate colony formation in the presence of pIXY 321, it did not abrogate the effect of bryostatin 1 on progenitor cell growth or lineage commitment. Finally, in contrast to its effects on committed myeloid progenitors, bryostatin 1 did not increase the growth of erythroid (burst-forming units-erythroid [BFU-E]) and multipotent (multipotent colony-forming units [CFU-GEMM]) progenitors stimulated by pIXY 321, but instead inhibited colony formation at higher concentrations (e.g., 10 to 100 nM).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Modulation of the activity of a human granulocyte-macrophage colony-stimulating factor/interleukin-3 fusion protein (pIXY 321) by the macrocyclic lactone protein kinase C activator bryostatin 1. 768 3

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) not only enhanced the growth of HL-60 cells, but also significantly increased NBT-reducing ability and alkaline phosphatase (ALP) activity of the cells, which were enhanced by the treatment with retinoic acid (RA). Protein kinase C inhibitors (H-7 and staurosporine) significantly suppressed this induction of ALP. The pretreatment with RA followed by rhG-CSF treatment showed almost the same degree of ALP activity as that induced by the simultaneous treatment with RA and rhG-CSF. This study suggests that RA and rhG-CSF are the potent inducers of ALP activity of HL-60 cells and protein kinase C is supposed to have a role in this induction of ALP.
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PMID:Alkaline phosphatase activity in the human promyelocytic leukemia cell line, HL-60, induced by retinoic acid and recombinant human granulocyte colony-stimulating factor. 768 28

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) (10 ng/mL) prolonged human neutrophil survival in culture by at least 36 hours. The addition of H-series compounds at concentrations that are considered to inhibit both protein kinase C (PKC) and cyclic adenylate monophosphate (cAMP)-dependent protein kinase (PKA) counteracted the effect of rhG-CSF. Concomitantly, the inhibition of nucleosomal DNA fragmentation by rhG-CSF was canceled. At lower concentrations, presumably capable of inhibiting only PKA, however, the compounds exhibited marginal effects on rhG-CSF-mediated increase of cell survival. These PKC inhibitors did not influence the priming effect of rhG-CSF significantly, as determined by O2- production stimulated by N-formyl-L-methionyl-L-leucyl phenylalanine (fMLP). Our results suggest that PKC plays an important role in the mechanism by which rhG-CSF promotes neutrophil survival, in striking contrast with the priming effect elicited by rhG-CSF.
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PMID:Role of protein kinase C in neutrophil survival enhanced by granulocyte colony-stimulating factor. 769 71


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