The Journal of Neuroscience, November 15, 1999, 19(22):9913-9927
Neuregulins Signaling via a Glial erbB-2-erbB-4 Receptor Complex
Contribute to the Neuroendocrine Control of Mammalian Sexual
Development
Ying J.
Ma1,
Diane F.
Hill1,
Kimberly E.
Creswick1,
Maria E.
Costa1,
Anda
Cornea1,
Mario N.
Lioubin2,
Gregory D.
Plowman2, and
Sergio R.
Ojeda1
1 Division of Neuroscience, Oregon Regional Primate
Research Center, Beaverton, Oregon 97006, and 2 Sugen,
Inc., South San Francisco, California 94080
Activation of erbB-1 receptors by glial TGF
has been shown to be
a component of the developmental program by which the neuroendocrine brain controls mammalian sexual development. The participation of other
members of the erbB family may be required, however, for full signaling
capacity. Here, we show that activation of astrocytic erbB-2/erbB-4
receptors plays a significant role in the process by which the
hypothalamus controls the advent of mammalian sexual maturation.
Hypothalamic astrocytes express both the erbB-2 and erbB-4
genes, but no erbB-3, and respond to neuregulins (NRGs) by
releasing prostaglandin E2 (PGE2), which acts on
neurosecretory neurons to stimulate secretion of luteinizing
hormone-releasing hormone (LHRH), the neuropeptide controlling sexual
development. The actions of TGF
and NRGs in glia are synergistic and
involve recruitment of erbB-2 as a coreceptor, via erbB-1 and erbB-4, respectively. Hypothalamic expression of both erbB-2 and erbB-4 increases first in a gonad-independent manner before the onset of
puberty, and then, at the time of puberty, in a sex steroid-dependent manner. Disruption of erbB-2 synthesis in hypothalamic astrocytes by
treatment with an antisense oligodeoxynucleotide inhibited the
astrocytic response to NRGs and, to a lesser extent, that to TGF
and
blocked the erbB-dependent, glia-mediated, stimulation of LHRH release.
Intracerebral administration of the oligodeoxynucleotide to developing
animals delayed the initiation of puberty. Thus, activation of the
erbB-2-erbB-4 receptor complex appears to be a critical component of
the signaling process by which astrocytes facilitate the acquisition of
female reproductive capacity in mammals.
Key words:
astroglial cells; tyrosine kinase receptors; glial growth
factors; female sexual development; hypothalamus; puberty
Copyright © 1999 Society for Neuroscience 0270-6474/99/19229913-15$05.00/0