Short-term delay of Fas-stimulated apoptosis by GM-CSF as a result of temporary suppression of FADD recruitment in neutrophils: evidence implicating phosphatidylinositol 3-kinase and MEK1-ERK1/2 pathways downstream of classical protein kinase C.
Granulocyte/macrophage colony-stimulating factor (GM-CSF) inhibits Fas-induced apoptosis of neutrophils. However, the exact step in the apoptotic pathway blocked by GM-CSF remained unclear. Here, we found that pretreatment of neutrophils with GM-CSF inhibits the recruitment of Fas-associated protein with death domain (FADD) to Fas, abolishing the formation of the death-inducing signaling complex required for Fas-induced apoptosis. Two-dimensional electrophoresis revealed that GM-CSF modifies the ratio of FADD subspecies. These GM-CSF-triggered changes were abrogated, and Fas-induced apoptosis was restored by an inhibitor of classical protein kinase C (PKC), Go6976, and by the combination of a phosphatidylinositol 3-kinase (PI-3K) inhibitor, LY294002, and an inhibitor of mitogen-activated protein kinase kinase (MEK)1, PD98059. Go6976 blocked GM-CSF-elicited phosphorylation of Akt/PKB and extracellular signal-regulated kinase (ERK)1/2. These results indicated that GM-CSF suppresses Fas-induced neutrophil apoptosis by inhibiting FADD binding to Fas, through redundant actions of PI-3K and MEK1-ERK1/2 pathways downstream of classical PKC.
Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan.
Yasuko
Y
Kotone-Miyahara
Kouhei
K
Yamashita
Kyung-Kwon
KK
Lee
Shin
S
Yonehara
Takashi
T
Uchiyama
Masataka
M
Sasada
Atsushi
A
Takahashi
D048868:Adaptor Proteins, Signal Transducing / Q000187:drug effects / Q000378:metabolism*; D000328:Adult; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D053200:Fas-Associated Death Domain Protein; D025461:Feedback, Physiological / Q000187:drug effects / Q000502:physiology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D048369:MAP Kinase Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology; D019869:Phosphatidylinositol 3-Kinases / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D013997:Time Factors; D019014:fas Receptor / Q000187:drug effects / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D053181:Caspase 8; D020169:Caspases; D004791:Enzyme Inhibitors; D053200:Fas-Associated Death Domain Protein; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D048369:MAP Kinase Kinase 1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D019869:Phosphatidylinositol 3-Kinases; D011493:Protein Kinase C; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D019014:fas Receptor; C505533:FADD protein, human; C494918:AKT1 protein, human; C482125:MAP2K1 protein, human; C505530:CASP8 protein, human