Intracellular fibroblast growth factor produces effects different from those of extracellular application on development of avian cochleovestibular ganglion cells in vitro.
In an avian coculture system, the neuronal precursors of the cochleovestibular ganglion typically migrated from the otocyst and differentiated in response to soluble fibroblast growth factor (FGF-2), which had free access to FGF receptors on the cell surface. Free FGF-2 switched cells from a proliferation mode to migration, accompanied by increases in process outgrowth, fasciculation, and polysialic acid expression. Microsphere-bound FGF-2 had some of the same effects, but in addition it increased proliferation and decreased fasciculation and polysialic acid. As shown by immunohistochemistry, FGF-2 that was bound to latex microspheres depleted the FGF surface receptor protein, which localized with the microspheres in the cytoplasm and nucleus. For microsphere-bound FGF-2, the surface receptor-mediated responses to FGF-2 appear to be limited and the door opened to another venue of intracellular events or an intracrine mechanism.
Bilak
Masako M
MM
Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut, USA.
Hossain
Waheeda A
WA
Morest
D Kent
DK
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D003051:Cochlea / Q000196:embryology / Q000294:innervation*; D018920:Coculture Techniques; D005110:Extracellular Space / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000737:chemistry / Q000494:pharmacology*; D007424:Intracellular Fluid / Q000378:metabolism; D008863:Microspheres; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017468:Receptors, Fibroblast Growth Factor / Q000096:biosynthesis; D012995:Solubility; D013136:Spiral Ganglion / Q000166:cytology / Q000187:drug effects* / Q000196:embryology; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D014722:Vestibule, Labyrinth / Q000196:embryology / Q000294:innervation*
D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2