Specific inhibitor of FGF receptor signaling: FGF-2-mediated effects on proliferation, differentiation, and MAPK activation are inhibited by PD173074 in oligodendrocyte-lineage cells.
Multiple studies have shown that migration, proliferation, and differentiation of oligodendrocyte (OL) lineage cells are influenced by fibroblast growth factor-2 (FGF-2) signaling through its receptors (FGFR) FGFR-1, FGFR-2, and FGFR-3. We report the effectiveness and specificity of a unique inhibitor, PD173074, for inhibiting FGF receptor signaling in OL-lineage cells. Three FGF-mediated responses of OL progenitors and two of differentiated OLs were examined by immunofluorescence microscopy and immunoblotting. PD173074 effectively antagonized the effect of FGF-2 on proliferation and differentiation of OL progenitors in culture. One dose of PD173074 at nanomolar concentrations was sufficient to inhibit ongoing FGF-2 mediated proliferation for prolonged periods, in a non-toxic, dose-dependent manner. In contrast, platelet-derived growth factor (PDGF)-induced proliferation was unaffected by PD173074. Similarly, mitogen-activated protein kinase (MAPK) activation, a downstream event after activation of either FGFR or PDGFR, was also blocked by PD173074 in OL progenitors stimulated with FGF-2 but not PDGF. A general tyrosine kinase inhibitor (PD166285), however, antagonized both FGF-2- and PDGF-mediated responses. PD173074 also completely antagonized two phenotypic alterations of differentiated OLs, specifically downregulation of myelin proteins, and their re-entry into the cell cycle. We conclude that PD173704 is an effective and specific inhibitor for multiple FGF-2-mediated responses of both OL progenitors and differentiated OLs. This inhibitor provides a direct approach for identifying the importance of FGF signaling, comparable in effect to a knockout of all FGF receptors and all FGF ligands, while leaving other pathways unaffected. Thus, PD173704 is an excellent tool for investigating the role of FGF signaling in vivo in the context of combinatorial interactions of other signals.
Department of Neuroscience, University of Connecticut Medical School, Farmington, CT 06030-3401, USA. bansal@neuron.uchc.edu
Rashmi
R
Bansal
Suma
S
Magge
Susan
S
Winkler
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D016222:Fibroblast Growth Factor 2 / Q000502:physiology*; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D009185:Myelin Proteins / Q000187:drug effects / Q000378:metabolism; D009836:Oligodendroglia / Q000187:drug effects* / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000502:physiology; D011743:Pyrimidines / Q000494:pharmacology*; D051381:Rats; D017468:Receptors, Fibroblast Growth Factor / Q000037:antagonists & inhibitors / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects; D013234:Stem Cells / Q000187:drug effects* / Q000378:metabolism
D009185:Myelin Proteins; C115711:PD 173074; D010982:Platelet-Derived Growth Factor; D011743:Pyrimidines; D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; D020928:Mitogen-Activated Protein Kinases