BMP-2 augments FGF-induced differentiation of PC12 cells through upregulation of FGF receptor-1 expression.
When exposed to various neurotrophic factors, including fibroblast growth factors (FGF)-1 and -2, rat pheochromocytoma-derived PC12 cells differentiate into sympathetic neuron-like cells possessing elongated neurites. We found that while bone morphogenetic protein-2 (BMP-2) exerted little effect by itself on the differentiation of PC12 cells, in combination with FGF it strongly induced neurite outgrowth, even at subthreshold concentrations of FGF. Analysis of gene expression revealed that FGF receptor-1 (FGFR-1) mRNA was abundantly expressed in PC12 cells and that its expression was upregulated by pretreating the cells with BMP-2. Crosslinking the receptors with (125)I-FGF-2 and then immunoprecipitating them confirmed that expression of FGFR-1, but not other FGF receptor types, was enhanced by BMP-2. Furthermore, Scatchard analyses revealed that the numbers of FGF-2 binding sites were increased by approximately 40% after BMP-2 treatment. Pretreatment with BMP-2 also enhanced peak and sustained levels of FGF-induced ERK1/2 phosphorylation in PC12 cells. Finally, the augmentation of neurotrophic activity by BMP-2 was inhibited by SU5402, an FGFR-1 inhibitor. These findings indicate that BMP-2 augments FGF-induced differentiation of PC12 cells through selective upregulation of FGFR-1 expression, and suggest that BMP-2 and FGF act in concert to regulate cell differentiation in the nervous system.
Hayashi
H
H
Gene Discovery Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan.
Ishisaki
A
A
Suzuki
M
M
Imamura
T
T
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000378:metabolism* / Q000494:pharmacology; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000494:pharmacology; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016220:Fibroblast Growth Factor 1; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D020932:Nerve Growth Factor / Q000494:pharmacology; D016501:Neurites / Q000502:physiology; D016716:PC12 Cells; D010455:Peptides / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D012333:RNA, Messenger; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D051906:Smad7 Protein; D015534:Trans-Activators / Q000494:pharmacology; D016212:Transforming Growth Factor beta; D015854:Up-Regulation
C525718:BMP2 protein, human; C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D010455:Peptides; D011758:Pyrroles; D012333:RNA, Messenger; D017468:Receptors, Fibroblast Growth Factor; C497806:SMAD7 protein, human; C105686:SU 5402; D051906:Smad7 Protein; C497808:Smad7 protein, rat; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; D020932:Nerve Growth Factor; C496348:FGFR1 protein, human; C496350:Fgfr1 protein, rat; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases