Basic FGF induces neuronal differentiation, cell division, and NGF dependence in chromaffin cells: a sequence of events in sympathetic development.
To define further the molecules that control sympathoadrenal differentiation, we have investigated the effects of FGF, NGF, and glucocorticoid on cultured neonatal rat adrenal chromaffin cells. Basic FGF (bFGF), like NGF, induces cell division and neurite outgrowth from these cells. Dexamethasone inhibits neuronal differentiation but not proliferation induced by bFGF. Unlike NGF, bFGF will not support the survival of chromaffin cell-derived sympathetic neurons. However, bFGF induces a dependence on NGF. The overlapping but distinct responses to NGF and bFGF may underlie a sequence of events in sympathetic differentiation. bFGF (or another factor) may act locally in developing ganglia to stimulate mitotic expansion and initial axon outgrowth. Subsequent survival and maturation are then controlled by NGF, which is provided by peripheral targets of innervation. In the adrenal gland, glucocorticoids may permit bFGF to amplify the chromaffin population, while preventing neuronal differentiation.
Stemple
D L
DL
Division of Biology, California Institute of Technology, Pasadena 91125.
Mahanthappa
N K
NK
Anderson
D J
DJ
D000313:Adrenal Medulla / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004261:DNA Replication / Q000187:drug effects; D005346:Fibroblast Growth Factors / Q000494:pharmacology*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013936:Thymidine / Q000378:metabolism
D009414:Nerve Growth Factors; D005346:Fibroblast Growth Factors; D013936:Thymidine