scholarly journals Granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes phosphorylation and an increase in the activity of cytosolic phospholipase A2 in human neutrophils

1996 ◽  
Vol 313 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Nabeel NAHAS ◽  
Waltraut H. WATERMAN ◽  
Ramadan I. SHA'AFI
Keyword(s):  
Phospholipase A2 ◽  
Cytosolic Phospholipase A2 ◽  
Time Dependent ◽  
Human Neutrophils ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Cytosolic Phospholipase ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Incubation of human neutrophils with 500 pM granulocyte-macrophage colony-stimulating factor (GM-CSF) results in a rapid and time-dependent increase in the phosphorylation of cytosolic phospholipase A2 (cPLA2), which was reflected in a slower electrophoretic mobility of the enzyme. The GM-CSF-induced phosphorylation of cPLA2 was accompanied by a parallel and time-dependent increase in the enzyme activity. Preincubation of neutrophils with the tyrosine kinase inhibitor genistein caused inhibition of the GM-CSF-stimulated phosphorylation and activity of cPLA2. Immunoprecipitation of the enzyme following incubation of neutrophils with [32P]Pi shows that cPLA2 is phosphorylated by GM-CSF. Potato acid phosphatase caused dephosphorylation of the enzyme, indicating that cPLA2 is indeed phosphorylated by GM-CSF. The subcellular distribution of cPLA2 in GM-CSF-stimulated neutrophils revealed that the enzyme resides almost completely in the cytosolic fraction. Addition of Ca2+ to the lysis buffer before homogenization results in the translocation of the phosphorylated and the dephosphorylated forms of the enzyme to the membranes. Translocation of cPLA2 was also achieved after incubation with 0.1 μM N-formylmethionyl-leucyl-phenylalanine (fMLP) after GM-CSF stimulation and when neutrophils were challenged with the Ca2+ ionophore A23187. EDTA and EGTA were unable to solubilize the translocated enzyme from the neutrophil membranes, indicating that cPLA2 is attached to the membranes by strong bonds and not merely due to ionic forces exerted by Ca2+. The inability of GM-CSF to promote arachidonic acid mobilization is probably due to the fact that GM-CSF does not cause an increase in intracellular Ca2+, which is necessary for the translocation of the enzyme to the membranes where its substrate(s) reside.

scholarly journals Biologic properties in vitro of a recombinant human granulocyte- macrophage colony-stimulating factor

Blood ◽  
1986 ◽  
Vol 67 (1) ◽  
pp. 37-45 ◽  
Author(s):  
D Metcalf ◽  
CG Begley ◽  
GR Johnson ◽  
NA Nicola ◽  
MA Vadas ◽  
...  
Keyword(s):  
Colony Formation ◽  
Specific Activity ◽  
Human Neutrophils ◽  
Colony Stimulating Factor ◽  
Direct Stimulation ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor ◽  
Marrow Cultures

Recombinant human granulocyte-macrophage colony-stimulating factor (rH GM-CSF) was purified to homogeneity from medium conditioned by COS cells transfected with a cloned human GM-CSF cDNA and shown to be an effective proliferative stimulus in human marrow cultures for GM and eosinophil colony formation. The specific activity of purified rH GM- CSF in human marrow cultures was calculated to be at least 4 X 10(7) U/mg protein. Clone transfer experiments showed that this proliferation was due to direct stimulation of responding clonogenic cells. Acting alone, rH GM-CSF did not stimulate erythroid colony formation, but in combination with erythropoietin, increased erythroid and multipotential colony formation in cultures of peripheral blood cells. rH GM-CSF had no proliferative effects on adult or fetal murine hematopoietic cells, did not induce differentiation in murine myelomonocytic WEHI-3B cells, and was unable to stimulate the survival or proliferation of murine hematopoietic cell lines dependent on murine multi-CSF (IL 3). rH GM- CSF stimulated antibody-dependent cytolysis of tumor cells by both mature human neutrophils and eosinophils and increased eosinophil autofluorescence and phagocytosis by neutrophils. From a comparison of these effects with those of semipurified preparations of human CSF alpha and -beta, it was concluded that rH GM-CSF exhibited all the biologic activities previously noted for CSF alpha.

scholarly journals Direct stimulation by tyrosine phosphorylation of microtubule-associated protein (MAP) kinase activity by granulocyte-macrophage colony-stimulating factor in human neutrophils

1993 ◽  
Vol 291 (1) ◽  
pp. 211-217 ◽  
Author(s):  
J Gomez-Cambronero ◽  
J M Colasanto ◽  
C K Huang ◽  
R I Sha'afi
Keyword(s):  
Okadaic Acid ◽  
Kinase Activity ◽  
Human Neutrophils ◽  
Colony Stimulating Factor ◽  
Tyrosine Residues ◽  
Gm Csf ◽  
Mapk Activity ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Human polymorphonuclear neutrophils exhibit a low level of the microtubule-associated protein kinase (MAPK) activity. This enzymic activity is enhanced up to 3-fold upon cell stimulation with the human haematopoietic hormone granulocyte-macrophage colony-stimulating factor (GM-CSF). This is demonstrated both in whole-cell lysates and in DEAE-anion-exchange semi-purified fractions prepared from GM-CSF-stimulated neutrophils, by assaying the kinase activity against either myelin basic protein or a phosphoacceptor peptide that bears the specific phosphorylation site of the MAPK natural substrate. Similarly, phosphorylation of MAPK in tyrosine residues, as found in immunoblots using anti-phosphotyrosine antibodies, follows similar time- and dose-response curves as the kinase activation. Pretreatment of the cells with the tyrosine kinase inhibitor genistein abrogates the above-mentioned effect, whereas the phosphatase inhibitor okadaic acid enhances both the basal and the GM-CSF-stimulated kinase activities. Likewise, MAPK tyrosine phosphorylation is diminished in genistein-treated neutrophils, and enhanced in okadaic acid-treated cells. We conclude that MAPK activity is present in human neutrophils, and that it is stimulated by GM-CSF. This stimulation of the activity is most likely due to the phosphorylation of MAPK in tyrosine residues triggered upon binding of GM-CSF to its receptors.

scholarly journals Granulocyte-macrophage colony-stimulating factor induces a staurosporine inhibitable tyrosine phosphorylation of unique neutrophil proteins

Blood ◽  
1992 ◽  
Vol 79 (9) ◽  
pp. 2446-2454
Author(s):  
RL Berkow
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Kinase Inhibitor ◽  
Human Neutrophils ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Triton X ◽  
Stimulating Factor

Human neutrophils treated with chemotactic peptides or phorbol esters demonstrate tyrosine phosphorylation of a subset of proteins. Granulocyte-macrophage colony-stimulating factor (GM-CSF) induced a time- and concentration-dependent increase in the tyrosine phosphorylation of at least seven proteins. Three of these proteins with approximate molecular weights of 150, 95, and 70 Kd were unique to neutrophils treated with GM-CSF, and were not seen to be phosphorylated on tyrosine in neutrophils treated with the agonists FMLP or PMA, or the cytokines G-CSF and tumor necrosis factor. We found the 150-Kd protein to be localized within the cell particulate fraction and the 95- Kd protein within the cell cytosol. The 70-Kd phosphotyrosine protein was found in both fractions. When the neutrophils were treated with Triton X-100 (Sigma Chemical Co, St Louis, MO) to evaluate cytoskeletal associations of proteins, the 150 phosphotyrosine protein partitioned with the Triton X-100 insoluble cytoskeleton (TICS), and the 70-Kd protein partitioned with both the TICS and Triton X-100 soluble proteins. The GM-CSF-induced tyrosine phosphorylation was inhibited by the tyrosine kinase inhibitor ST638. This was not seen with the putative C-kinase inhibitor, H-7. However, staurosporine was seen to inhibit tyrosine phosphorylation of neutrophil proteins by GM-CSF and in vitro tyrosine kinase activity of isolated neutrophil cytosol and particulate fractions. These data indicate that the three unique GM-CSF- induced phosphotyrosine-containing proteins may be responsible for the unique actions of GM-CSF and that staurosporine inhibits a tyrosine kinase responsible for the phosphorylation of these proteins.

scholarly journals Up-regulation of the amount of Giα2 associated with the plasma membrane in human neutrophils stimulated by granulocyte-macrophage colony-stimulating factor

1993 ◽  
Vol 292 (1) ◽  
pp. 183-187 ◽  
Author(s):  
M Durstin ◽  
S R McColl ◽  
J Gomez-Cambronero ◽  
P H Naccache ◽  
R I Sha'afi
Keyword(s):  
Plasma Membrane ◽  
Kinase Inhibitor ◽  
Human Neutrophils ◽  
Protein Synthesis Inhibitor ◽  
Colony Stimulating Factor ◽  
Synthesis Inhibitor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Preincubation of human neutrophils with the human cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) results in an increase in the amount of alpha-subunit of Gi2 (Gi alpha 2) associated with the plasma membrane and a corresponding decrease in the amount associated with the granule fractions. Similar results are obtained with interleukin-8. GM-CSF has no effect on the distribution of Gi alpha 3. The effect of GM-CSF on Gi alpha 2 is time-dependent, and, although a significant effect can be observed after incubation for 5 min with GM-CSF, the enhancement increases with increasing time. Genistein, a protein tyrosine kinase inhibitor, and 1,2-bis-(O-aminophenoxyl)ethane-NNN'N'-tetra-acetic acid (BAPTA), an intracellular Ca2+ chelator, decrease the stimulatory effect of GM-CSF. On the other hand, the protein-synthesis inhibitor cycloheximide does not affect the action of GM-CSF. Also, although preincubation of human neutrophils with GM-CSF increases the levels of Gi alpha 2 in the plasma membrane it does not alter the total amount of cellular Gi alpha 2. In addition, the level of Gi alpha 2 mRNA, unlike that of the proto-oncogene c-fos, is not increased in cells treated with GM-CSF. This indicates that the observed increase in the amount of Gi alpha 2 associated with the plasma membrane is not due to the synthesis of new Gi alpha 2. These data provide insight into the mechanism by which GM-CSF may prime human neutrophils for increased responsiveness to subsequent stimulation by G-protein-dependent agonists.

Cytokine-Specific Activation of Distinct Mitogen-Activated Protein Kinase Subtype Cascades in Human Neutrophils Stimulated by Granulocyte Colony-Stimulating Factor, Granulocyte-Macrophage Colony-Stimulating Factor, and Tumor Necrosis Factor-

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 341-349 ◽  
Author(s):  
Kenichi Suzuki ◽  
Masayuki Hino ◽  
Fumihiko Hato ◽  
Noriyuki Tatsumi ◽  
Seiichi Kitagawa
Keyword(s):  
P38 Mapk ◽  
Mitogen Activated Protein Kinase ◽  
Human Neutrophils ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Mitogen Activated Protein ◽  
Upstream Kinase ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Abstract To clarify the differences of the signaling pathways used by granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor- (TNF), we investigated activation of mitogen-activated protein kinase (MAPK) subtype cascades in human neutrophils stimulated by these cytokines. G-CSF exclusively tyrosine-phosphorylated extracellular signal-regulated kinase (ERK). GM-CSF tyrosine-phosphorylated ERK strongly and p38 MAPK weakly, whereas TNF tyrosine-phosphorylated p38 MAPK strongly and ERK weakly. Consistent with these findings, MEK, an upstream kinase of ERK, was phosphorylated by G-CSF, GM-CSF, and TNF, whereas MKK3/MKK6, an upstream kinase of p38 MAPK, was phosphorylated by GM-CSF and TNF, but not by G-CSF. The potency of these cytokines to phosphorylate ERK and MEK was GM-CSF > G-CSF > TNF, whereas that to phosphorylate p38 MAPK and MKK3/MKK6 was TNF > GM-CSF. C-Jun amino-terminal kinase (JNK) was not tyrosine-phosphorylated by any cytokine despite the existence of JNK proteins in human neutrophils, whereas it was tyrosine-phosphorylated by TNF in undifferentiated and all-trans retinoic acid-differentiated HL-60 cells. Increased phosphorylation of ERK or p38 MAPK was detected within 1 to 5 minutes after stimulation with each cytokine and was dependent on the concentrations of cytokines used. MEK inhibitor (PD98059) reduced tyrosine phosphorylation of ERK, but not p38 MAPK, induced by G-CSF, GM-CSF, or TNF. GM-CSF– or TNF-induced superoxide (O2−) release was inhibited by p38 MAPK inhibitor (SB203580) in a dose-dependent manner, suggesting the possible involvement of p38 MAPK in GM-CSF– or TNF-induced O2− release. The results indicate that G-CSF, GM-CSF, and TNF activate the overlapping but distinct MAPK subtype cascades in human neutrophils and suggest that the differential activation of ERK and p38 MAPK cascades may explain the differences of the effects of these cytokines on human neutrophil functions.

scholarly journals Granulocyte/macrophage colony-stimulating factor stimulates the expression of the 5-lipoxygenase-activating protein (FLAP) in human neutrophils.

1994 ◽  
Vol 179 (4) ◽  
pp. 1225-1232 ◽  
Author(s):  
M Pouliot ◽  
P P McDonald ◽  
P Borgeat ◽  
S R McColl
Keyword(s):  
De Novo ◽  
Human Neutrophils ◽  
Protein Synthesis Inhibitor ◽  
Dependent Manner ◽  
Colony Stimulating Factor ◽  
Synthesis Inhibitor ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

The synthesis of leukotrienes in human blood neutrophils chiefly relies on the activity of two enzymes, phospholipase A2 and 5-lipoxygenase (5-LO). In turn, the activation of the 5-LO requires the participation of a recently characterized membrane-bound protein, the 5-LO-activating protein (FLAP). In this study, we have investigated conditions under which FLAP expression in neutrophils may be modulated. Of several cytokines tested, only granulocyte/macrophage colony-stimulating factor (GM-CSF) (and to a lesser extent tumor necrosis factor alpha) significantly increased expression of FLAP. GM-CSF increased FLAP mRNA steady-state levels in a time- and dose-dependent manner. The stimulatory effect of GM-CSF on FLAP mRNA was inhibited by prior treatment of the cells with the transcription inhibitor, actinomycin D, and pretreatment of the cells with the protein synthesis inhibitor, cycloheximide, failed to prevent the increase in FLAP mRNA induced by GM-CSF. The accumulation of newly synthesized FLAP, as determined by immunoprecipitation after incorporation of 35S-labeled amino acids, was also increased after incubation of neutrophils with GM-CSF. In addition, the total level of FLAP protein was increased in GM-CSF-treated neutrophils, as determined by two-dimensional gel electrophoresis, followed by Western blot. GM-CSF did not alter the stability of the FLAP protein, indicating that the effect of GM-CSF on FLAP accumulation was the consequence of increased de novo synthesis as opposed to decreased degradation of FLAP. Finally, incubation of neutrophils with the synthetic glucocorticoid dexamethasone directly stimulated the upregulation of FLAP mRNA and protein, and enhanced the effect of GM-CSF. Taken together, these data demonstrate that FLAP expression may be upmodulated after appropriate stimulation of neutrophils. The increase in FLAP expression induced by GM-CSF in inflammatory conditions could confer upon neutrophils a prolonged capacity to synthesize leukotrienes.

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