M. Daadi et al., ACTIVIN COOPERATES WITH FIBROBLAST-GROWTH-FACTOR-2 TO REGULATE TYROSINE-HYDROXYLASE EXPRESSION IN THE BASAL FOREBRAIN VENTRICULAR ZONE PROGENITORS, Neuroscience, 86(3), 1998, pp. 867-880
Activin and its cognate receptors are expressed during embryogenesis i
n the rapidly dividing cells of the basal forebrain ventricular zone.
This finding prompted us to study the role of activin in regulating ne
urotransmitter phenotype expression and other aspects of the ventricul
ar zone-derived progenitor cell differentiation. although virtually in
effective alone, activin co-operated with fibroblast growth factor 2 t
o induce a rapid tyrosine hydroxylase-immunoreactivity in cultured ven
tricular zone progenitors. Northern analysis indicated that the increa
se in tyrosine hydroxylase-immunoreacrivity was associated with increa
sed tyrosine hydroxylase gene expression. Activin and fibroblast growt
h factor 2 action was specific to tyrosine hydroxylase, as it did not
induce the expression of choline acetyltransferase, nor enhance the ex
pression of glutamate decarboxylase. Cultures treated with the DNA rep
lication marker bromodeoxyuridine revealed that both proliferating ven
tricular zone progenitors and their post-mitotic progeny were induced
to express tyrosine hydroxylase. In these cultures, activin acted to r
educe fibroblast growth Factor 2 stimulated mitotic activity. Furtherm
ore, activin permitted neuronal differentiation and survival of the ve
ntricular zone progenitors after three days in vitro. Together these d
ata demonstrate a novel role of activin and fibroblast growth factor 2
in regulating the Fate of the embryonic basal forebrain ventricular z
one progenitors. (C) 1998 IBRO. Published by Elsevier Science Ltd.