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)

The generation of diradylglycerol (DRG) and phosphatidic acid (PdtOH) was investigated in neutrophils primed with granulocyte-macrophage colony-stimulating factor (GM-CSF). Mass accumulation of DRG and PdtOH was measured using reversed-phase high performance liquid chromatography and thin layer chromatography, respectively. GM-CSF had no direct effect on the levels of PdtOH and DRG, but it increased PdtOH generation and the late phase of DRG accumulation in human neutrophils stimulated with FMLP. The elevation of the mass of PdtOH peaked approximately 100 s and clearly preceded that of DRG, which peaked at 150 s. The diacylglycerol kinase inhibitor R59022 enhanced the sustained increase in DRG but did not produce a parallel inhibition in PdtOH production. GM-CSF was without effect on the level of inositol 1,4,5-triphosphate [Ins(1,4,5)P3] and did not affect the liberation of Ins(1,4,5)P3 induced by FMLP. These findings exclude the involvement of the PtdIns(4,5)P2-specific phospholipase C/diacylglycerol pathway in the sustained phase of DRG accumulation. The early (30-s) appearance of PdtOH clearly suggests that GM-CSF enhanced FMLP receptor-linked phospholipase D (PLD) generation of PdtOH. PLD was assessed more directly by formation of labeled phosphatidylethanol (PEt) through PLD capacity of catalyzing a trans-phosphatidylation in presence of ethanol. The formation of PEt associated with a concomitant decrease in PdtOH directly demonstrated that the mechanism by which GM-CSF enhances PdtOH production is activation of a PLD active on phosphatidylcholine. This study provides evidence that the mechanism of action of GM-CSF involves upregulation of PLD activity leading to enhanced generation of PdtOH and DRG in FMLP-stimulated neutrophils. These findings may provide the basis for several of the priming effects of GM-CSF.
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PMID:Involvement of a phospholipase D in the mechanism of action of granulocyte-macrophage colony-stimulating factor (GM-CSF): priming of human neutrophils in vitro with GM-CSF is associated with accumulation of phosphatidic acid and diradylglycerol. 220 47

The migration of neutrophils into sites of acute and chronic inflammation is mediated by chemokines. We used degenerate-primer reverse transcriptase-polymerase chain reaction (RT-PCR) to analyze chemokine receptor expression in neutrophils and identify novel receptors. RNA was isolated from human peripheral blood neutrophils and from neutrophils that had been stimulated for 5 h with granulocyte-macrophage colony-stimulating factor or by coculturing with primary human bronchial epithelial cells. Amplification products were cloned, and clone redundancy was determined. Seven known G-protein-coupled receptors were identified among 38 clones-CCR1, CCR4, CXCR1, CXCR2, CXCR4, HM63, and FPR1-as well as a novel gene, EX33. The full-length EX33 clone was obtained, and an in silico approach was used to identify the putative murine homologue. The EX33 gene encodes a 396-amino-acid protein with limited sequence identity to known receptors. Expression studies of several known chemokine receptors and EX33 revealed that resting neutrophils expressed higher levels of CXCRs and EX33 compared with activated neutrophils. Northern blot experiments revealed that EX33 is expressed mainly in bone marrow, lung, and peripheral blood leukocytes. Using RT-PCR analysis, we showed more abundant expression of EX33 in neutrophils and eosinophils, in comparison with that in T- or B-lymphocytes, indicating cell-specific expression among leukocytes.
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PMID:Cloning and expression analysis of a novel G-protein-coupled receptor selectively expressed on granulocytes. 1140 93

Recently we demonstrated the existence of a phosphatidylinositol 3-kinase (PI3K)-independent F-actin polymerization during neutrophil pseudopod extension. Here we examine the use of the PI3K-dependent and PI3K-independent pathways of activation by the N-formyl peptide receptor and the chemokine receptors, and the priming of the 2 pathways by granulocyte-macrophage colony-stimulating factor (GM-CSF) and insulin. The inhibition of PI3K activity with wortmannin showed that rate of pseudopod extension stimulated with N-formyl-Met-Leu-Phe (fMLP was mostly dependent on PI3K, while the rate of interleukin-8 (IL-8)-stimulated pseudopod extension was less dependent on PI3K. The incubation of cells with either GM-CSF or insulin increased the rate of pseudopod extension by 50% when the cells were stimulated with IL-8 but not with fMLP. The stimulation with IL-8 phosphorylated the PI3K regulatory subunit. This phosphorylation was enhanced by GM-CSF, which increased PI3K activity and total phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) production. The effect of GM-CSF was blocked with wortmannin. In contrast, insulin did not increase p85 phosphorylation and did not enhance PI3K activity or PtdIns(3,4,5)P3 production. The effect of insulin was insensitive to wortmannin; however, it was blocked by an Src homology 2 (SH2)-binding peptide. These data indicate that priming of IL-8 activation with GM-CSF was mediated via the PI3Ks of class IA, while priming with insulin used a PI3K-independent pathway.
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PMID:Novel pathways of F-actin polymerization in the human neutrophil. 1276 41