Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Secretion of unique eosinophil granule constituents may play a role in allergic and parasitic reactions. Therefore we have investigated possible mechanisms for regulation of secretion in eosinophils. A hemolytic plaque assay and an enzyme-linked immunospot (ELISPOT) assay were developed for detection of secreted eosinophil cationic protein (ECP) from single adherent eosinophils. The protein kinase C activator phorbol 12-myristate 13-acetate (PMA) induced release of ECP in a dose-dependent fashion but 4-alpha-PMA, an analogue that does not activate protein kinase C, did not cause degranulation. Staurosporine and K252a, inhibitors of protein kinase C, decreased PMA-induced ECP secretion. Low concentrations of cytochalasin B enhanced PMA-induced secretion but high concentrations had an inhibitory effect. The calcium ionophores A23187 and ionomycin were weaker secretagogues than PMA. Tumor necrosis factor, granulocyte-macrophage colony-stimulating factor, interleukin-3, interleukin-5, N-formylmethionyl-leucyl-phenylalanine, and lipopolysaccharide caused little or no degranulation in adherent eosinophils. Preincubation of eosinophils with antibodies to CD18, the common beta chain of leukocyte adhesion proteins, resulted in inhibition of PMA-induced ECP release from adherent cells. 1,2-Bis(O-aminophenyl)-ethane-ethane-N,N,N',N'-tetraacetic acid (BAPTA), an agent that acts intracellularly by chelation of calcium, also inhibited PMA-mediated ECP release. In conclusion, PMA induces release of ECP from single adherent eosinophils and the effect appears to be mediated via protein kinase C and, in contrast to that in neutrophils, to be dependent on CD11/CD18 leukocyte integrins.
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PMID:Phorbol ester-induced degranulation in adherent human eosinophil granulocytes is dependent on CD11/CD18 leukocyte integrins. 809 65

Two cis-acting elements GM-kappa B/GC-box and CLE0, of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene are required for maximal induction in Jurkat T cells by costimulation with phorbol-12-myristate acetate (PMA) and Ca2+ ionophore (A23187). The GM-kappa B sequence is recognized by NF-kappa B, which is mainly induced by PMA. The CLE0 sequence interacts with factors, related to a PMA-induced AP-1 and a PMA/A23187-induced NF-AT. We examined whether signal transducing components in T cells can activate transcription of the GM-CSF gene. Cotransfection of NF-kappa B (p50/p65)- or AP-1 (c-Jun/c-Fos)-expression vectors into Jurkat cells with a luciferase reporter containing the GM-CSF promoter did not stimulate transcription from the GM-CSF promoter. In contrast, cotransfection with a combination of NF-kappa B and AP-1 significantly augmented transcription from the GM-CSF promoter containing the GM-kappa B/GC-box and the CLE0 (AP-1/NF-AT). Expression of a constitutively active calcineurin (CN), a Ca2+/calmodulin-dependent protein phosphatase, potentiated by two fold the transcriptional activation by NF-kappa B/AP-1. Both constitutively active forms of CN and protein kinase C (PKC) synergistically activated transcription from the GM-CSF promoter. These results suggest that cooperation among NF-kappa B-, AP-1- and NF-AT-binding sequences is required for induction of the GM-CSF gene through PKC- and Ca2+-signaling pathways downstream of T cell activation.
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PMID:Calcineurin activates transcription from the GM-CSF promoter in synergy with either protein kinase C or NF-kappa B/AP-1 in T cells. 813 80

The granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor is composed of an alpha subunit which binds GM-CSF and a beta subunit, which together form the high affinity receptor. By transfecting the human alpha subunit into murine Ba/F3 cells, we have been able to investigate the role of the short 54-amino acid intracytoplasmic portion (amino acid 346-400) of this subunit in mediating cell growth. We have shown that the intracytoplasmic amino acids 346-382 are necessary for GM-CSF-mediated cell growth. In contrast, amino acids 382-400 can be removed without effect. The stable transfection of the human beta subunit into the cell lines containing the mutant alpha subunits did not affect the growth characteristics of these cells. The ability of GM-CSF to stimulate cell growth of the Ba/F3 cells alpha subunit transfectants was correlated with the ability of this hormone to translocate protein kinase C to the particulate fraction. In contrast, the ability of GM-CSF addition to increase phosphorylation of the human beta subunit did not correlate with cell growth and required the entire intracytoplasmic domain of the alpha subunit. These results demonstrate an important role for the intracytoplasmic portion of the alpha subunit in mediating both signal transduction and cell cycle commitment stimulated by GM-CSF.
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PMID:Mapping the intracytoplasmic regions of the alpha granulocyte-macrophage colony-stimulating factor receptor necessary for cell growth regulation. 818 67

We investigated the effects of rac-1-O-octadecyl-2-O-methyl-glycero-3-phosphocholine (ET-18-OCH3) and 12-O-tetradecanoylphorbol-13-acetate (TPA) on granulocyte-macrophage colony-stimulating factor (GM-CSF) binding to human leukemic cell lines HL60, U937, KG-1, KG-1a, and K562. HL60, U937, and KG-1 exhibited the high-affinity receptors, but KG-1a and K562 revealed no demonstrable receptors. ET-18-OCH3 inhibited GM-CSF binding to HL60, U937, and KG-1 cells with a half-maximal inhibitory concentration of 16, 10, and 78 microM, respectively. ET-18-OCH3 at 10 microM reduced GM-CSF binding sites on HL60, U937, and KG-1, but had little effect on the dissociation constant (Kd). ET-18-OCH3 at 10 and 30 microM significantly (p < 0.01) decreased, in a dose-dependent manner, the total uptake, surface binding, and internalization of GM-CSF. The internalization of GM-CSF was more profoundly inhibited than its surface binding. TPA at 1 and 10 nM inhibited GM-CSF binding. Inhibition of GM-CSF binding by a combination of ET-18-OCH3 (10 microM) and TPA (1 or 10 nM) was less than additive, and ET-18-OCH3 partially inhibited TPA-induced protein kinase C (PKC) depletion in the cytosol and translocation to the particulate fractions. It is suggested that the inhibition of GM-CSF binding by ET-18-OCH3 is due in part to disruption of the plasma membrane and that the inhibition of GM-CSF binding by TPA is due to activation of PKC.
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PMID:Different mechanisms of inhibition by alkyl-lysophospholipid and phorbol ester of granulocyte-macrophage colony-stimulating factor binding to human leukemic cell lines. 828 54

We have examined the in vivo radioprotective effects of the macrocyclic lactone protein kinase C (PK-C) activator, bryostatin 1, administered either alone or in conjunction with recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF), in Balb/c and C3H/HeN mice subjected to lethal total body irradiation (TBI). When administered alone on a divided dose schedule (24 hours and 30 minutes before TBI), rmGM-CSF (20 micrograms/kg) was ineffective in increasing survival in either strain. However, in Balb/c mice, bryostatin 1 alone (1 microgram) permitted the long-term survival (60 days) of 70% of the animals following TBI, and 80% when administered in conjunction with rmGM-CSF. Bryostatin 1 administered alone according to this schedule exerted minimal radioprotective effects in C3H/HeN mice, but, when combined with a subeffective dose of rmGM-CSF, allowed 50% of the animals to survive. Treatment of Balb/c mice with bryostatin 1 administered as a single dose 4 hours before TBI resulted in a 20% survival rate, and 45% when administered with rmGM-CSF; corresponding values for the C3H/HeN strain were 60% and 40%, respectively. Lastly, the survival rates of Balb/c mice treated with bryostatin 1 administered as a single dose 4 hours following TBI was 20%, and 25% with rmGM-CSF; corresponding values were 50% and 25% for C3H/HeN mice. These findings indicate that the PK-C activator bryostatin 1 exhibits intrinsic in vivo radioprotective effects in lethally irradiated Balb/c and C3H/HeN mice, and may, under some circumstances, augment the radioprotective capacity of rmGM-CSF. They also underscore the critical role that strain differences and scheduling considerations play in determining the in vivo radioprotective capacity of bryostatin 1, as well as its interactions with rmGM-CSF.
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PMID:The macrocyclic lactone protein kinase C activator, bryostatin 1, either alone, or in conjunction with recombinant murine granulocyte-macrophage colony-stimulating factor, protects Balb/c and C3H/HeN mice from the lethal in vivo effects of ionizing radiation. 829 28

The influence of pooled human IgG preparations for intravenous use (i.v.Ig) on in vitro-induced cytokine production was studied at the single-cell level using cytokine-specific monoclonal antibodies (mAb) and indirect immunofluorescent technique. Cultured mononuclear cells from peripheral blood from healthy adult donors were polyclonally stimulated for 96 hr by either direct ligation of T-cell receptors using immobilized anti-CD3 mAb or by a combination of a protein kinase C activator [phorbol 12-myristate 13-acetate (PMA)] and a calcium ionophore (ionomycin) in the absence or presence of i.v.Ig. A marked inhibition of proliferation and blast transformation was noted in all i.v.Ig exposed cultures, despite good cell survival. The production of the T-cell lymphokines interleukin-2 (IL-2), IL-10,interferon-gamma (IFN-gamma) and tumour necrosis factor-beta (TNF-beta) was significantly down-regulated during the whole studied period in the i.v.Ig containing anti-CD3 stimulated cultures. The synthesis of the monokine IL-8 was not suppressed and that of TNF-alpha, which was made by both lymphocytes and monocytes, was only moderately inhibited. Somewhat different and more transient effects were observed in the i.v.Ig-exposed PMA/ionomycin-activated cultures. The production of IL-2, IL-3, IL-4, IL-5, IL-10, TNF-beta and granulocyte-macrophage colony-stimulating factor (GM-CSF) was down-regulated during the initial phase of the cultures up to 48 hr, but not at 48-96 hr. The synthesis of IFN-gamma and TNF-alpha was unaffected of the influence of i.v.Ig during the entire culture period. The expression of IL-2 receptors (IL-2R) was significantly suppressed in the i.v.Ig-treated anti-CD3-activated cells, but not in the PMA/ionomycin-stimulated cultures. Taken together our results indicate that pooled IgG may mediate immunomodulation by direct effects on cytokine production and on T-cell proliferation.
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PMID:Down-regulation of cytokine production and interleukin-2 receptor expression by pooled human IgG. 834

Murine peritoneal exudate macrophages (PEM) co-express granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage CSF (M-CSF) receptors, among others. Treatment of PEM with lipopolysaccharide (LPS) or tumor-promoting phorbol ester (12-O-tetradecanoylphorbol-13-acetate [TPA]) induces a rapid but transient loss of M-CSF receptors in PEM. GM-CSF receptors are not affected by this treatment. The loss of M-CSF receptors induced by LPS can be inhibited by neomycin and compound 48/80, two potent phospholipase C (PLC) inhibitors, but not by phospholipase A2, calpain, protein kinase C (PKC) or protease inhibitors. On the other hand, the loss of M-CSF receptors induced by TPA has been prevented by PKC inhibitors but not by PLC inhibitors. PLC inhibitors also prevent LPS-suppressed receptor-mediated internalization of radiolabeled recombinant human (rh) M-CSF by macrophages. Similar prevention of LPS-induced M-CSF receptor downregulation was observed in human monocytes that had been pretreated with PLC inhibitors. Our results show that 1) TPA-induced M-CSF receptor loss is strictly dependent on PKC activation; 2) PLC activation alone also leads to downregulation of M-CSF receptors; and 3) LPS-induced M-CSF receptor downregulation in PEM is mediated primarily through a PLC-dependent pathway. Our data also imply that the expression of M-CSF but not GM-CSF receptors is linked to an important, yet unknown, PLC-sensitive component(s) whose hydrolysis may lead to downregulation of M-CSF receptors.
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PMID:Downregulation of M-CSF receptors by lipopolysaccharide in murine peritoneal exudate macrophages is mediated through a phospholipase C dependent pathway. 851 62

Interferon-gamma (IFN-gamma) is a priming agent of polymorphonuclear neutrophilic granulocyte (PMN) oxygen metabolism, and protein kinase C (PKC) is traditionally believed to play a central role in activation of this oxygen metabolism. In the present study, we have shown that the PKC activity in PMN is affected by IFN-gamma. After only 2 minutes exposure to IFN-gamma (100 U/ml), PKC activity was significantly increased in the noncytosolic fraction of the cells. This increase was transient, but toward the end of the priming period of 2 h, the membrane-associated PKC activity increased again to about 152% of control. In the cytosolic fraction, a small and hardly detectable decrease in PKC activity was observed. Treatment of PMN with granulocyte-macrophage colony-stimulating factor (GM-CSF), another PMN priming agent, showed no significant effects on the PKC activity. When the cells were stimulated with the bacterial peptide fMLP after a priming period with IFN-gamma or GM-CSF for 2 h, no significant difference between treated and control cells could be observed. PMN oxygen metabolism, measured by flow cytometry as an accumulation of the fluorescent compound dichlorofluorescein, was in these experiments significantly primed by IFN-gamma, both at baseline and when stimulated with fMLP. The protein kinase C inhibitors H7 and Ro31-8220 blocked the fMLP responses to some extent, but not completely. However, no significant difference between fMLP responses in control and IFN-gamma-treated cells could be detected after administration of inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interferon-gamma affects protein kinase C activity in human neutrophils. 853 5

The protein kinase C (PKC) activator bryostatin 1 (bryo) has substantial antileukemic and hematopoietic actions. Bryo promotes the in vitro growth of normal hematopoietic progenitors by inducing the release of growth factors from accessory cells. We have examined the effects of bryo on the expression and release of certain myeloid growth factors from fibroblastlike marrow stromal cells (MSC). Substantial release of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF). or interleukin-6 (IL-6) following bryo treatment was seen only in MSC cultures contaminated with macrophages. Bryo alone was ineffective in inducing release of the cytokines from MSC cultures containing only fibroblastlike stromal cells. When MSC were treated with IL-1alpha, substantial quantities of the cytokines (G-CSF, GM-CSF,IL-6) were released. Bryo acted synergistically with IL-1 alpha to significantly increase cytokine release to- to nine-fold compared to IL-1alpha alone (p < 0.016). Neither Il-1alpha nor bryo, alone or in combination, induced release of stem cell factor (scf) from MSC. The synergistic interaction between IL-1alpha and bryo was dose- and schedule-dependent, requiring simultaneous application of IL-1alpha and bryo for optimum effect. Bryo alone induced no G-CSF mRNA accumulation but increased the level seen with IL-1alpha treatment by 50%. The synergistic interaction of bryo and IL-1alpha required PKC, since it was antagonized by agents which depleted or inhibited PKC but not by a protein kinase A antagonist. The increase in G-CSF mRNA was associated with a marked increase in mRNA stability. Bryostatin may promote the release of cytokines from several accessory cell populations, including MSC, to accomplish its in vivo hematopoietic effects.
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PMID:Bryostatin 1 acts synergistically with interleukin-1 alpha to induce secretion of G-CSF and other cytokines from marrow stromal cells. 860 66

Phosphatidylinositol (PI) 3-kinase is activated as a result of cytokine-induced association of the enzyme with specific tyrosine-phosphorylated proteins. PI 3-kinase lipid products, PI 3, 4-P2 and PI 3,4,5-P3, have been shown, in vitro, to directly activate novel and atypical protein kinase C (PKC) isozymes. However, the mechanism by which PI 3-kinase may be involved in regulation of PKC isoforms in vivo is presently unknown. We investigated a possible relationship by looking for associations between these enzymes. We found that in a human erythroleukemia cell line, as well as in rabbit platelets, PI 3-kinase and PKCdelta associate in a specific manner that is modulated by cell activation. Granulocyte-macrophage colony-stimulating factor treatment of cells caused increased association of PKCdelta and PI 3-kinase as did treatment of platelets with platelet-activating factor. Results using two PI 3-kinase inhibitors, wortmannin and LY-294002, showed that the former inhibited this association, while the latter did not, suggesting that PI 3-kinase lipid products may not be a prerequisite for the PI 3-kinase/PKCdelta association. Our results also suggest that tyrosine phosphorylation of PKCdelta is not involved in its association with PI 3-kinase.
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PMID:Protein kinase C delta specifically associates with phosphatidylinositol 3-kinase following cytokine stimulation. 866 29


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