PLC-gamma activation is required for PDGF-betaR-mediated mitogenesis and monocytic differentiation of myeloid progenitor cells.
To investigate the molecular mechanisms mediating hematopoietic cell differentiation and mitogenesis by activation of the platelet-derived growth factor beta receptor (PDGF-betaR), the wild type PDGF-betaR (PDGF-betaRWT) and tyrosine to phenylalanine mutants of the PDGF-betaR, including F751, F966, F970, F1009, F1021 and F1009/F1021 were overexpressed in FDC-P2 myeloid progenitor cells by retroviral-mediated gene transfer. Stimulation of PDGF-betaRWT and F966, F970 and F1009 infectants with PDGF-BB led to the increased expression of monocytic differentiation markers. In contrast, activation of PDGF-betaR in the parental line or the F1021 or F1009/F1021 mutant infectants failed to induce monocytic differentiation. PDGF-BB stimulation of PDGF-betaRWT, F751, F966, F970 and F1009 infectants led to pronounced DNA synthesis, whereas F1021 and F1009/F1021 infectants did not reveal any increase in mitogenesis when compared to that of the FDC-P2 line. While PDGF stimulation of FDC-P2 cells overexpressing PDGF-betaRWT led to a pronounced increase in inositol phosphate formation due to phospholipase C-gamma (PLC-gamma) activation, PDGF-BB induced phosphoinositol hydrolysis was completely abolished in the F1021 and F1009/F1021 infectants. GF 109203X, a specific inhibitor of protein kinase C (PKC) activation, fully blocked PDGF-betaR-mediated monocytic differentiation and mitogenesis. Taken together, these results suggest that stimulation of the PDGF-betaR signaling pathway can mediate monocytic differentiation when PDGF-betaR is expressed at sufficient levels and that activation of PLC-gamma and PKC plays a pivotal role in PDGF-betaR-mediated differentiation and mitogenesis in FDC-P2 cell system.
Alimandi
M
M
Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892, USA.
Heidaran
M A
MA
Gutkind
J S
JS
Zhang
J
J
Ellmore
N
N
Valius
M
M
Kazlauskas
A
A
Pierce
J H
JH
Li
W
W
D001665:Binding Sites; D002454:Cell Differentiation / Q000235:genetics; D004247:DNA / Q000096:biosynthesis; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008301:Maleimides / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism; D009154:Mutation; D010649:Phenylalanine / Q000235:genetics; D051966:Phospholipase C gamma; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D020797:Receptor, Platelet-Derived Growth Factor beta; D017479:Receptors, Platelet-Derived Growth Factor / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014443:Tyrosine / Q000235:genetics / Q000378:metabolism
D004791:Enzyme Inhibitors; D007211:Indoles; D007527:Isoenzymes; D008301:Maleimides; D010982:Platelet-Derived Growth Factor; D011994:Recombinant Proteins; D014443:Tyrosine; D010649:Phenylalanine; D004247:DNA; D020797:Receptor, Platelet-Derived Growth Factor beta; D017479:Receptors, Platelet-Derived Growth Factor; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; C070515:bisindolylmaleimide I