Abstract
In recent years evidence has begun to accumulate indicating that the central control of mammalian puberty requires not only changes in transsynaptic communication, but also the participation of glial cells. Neurons and astrocytes control the pubertal process by regulating the secretory activity of those neurons that produce luteinizing hormone-releasing hormone (LHRH), the neuropeptide that governs sexual development. LHRH, in turn, directs sexual development by stimulating the secretion of pituitary gonadotropins. Astrocytes affect LHRH neuronal function via cell-cell signaling mechanisms involving several growth factors acting via receptors endowed with tyrosine kinase activity. We have identified two members of the epidermal growth factor/transforming growth factor alpha (EGF/TGFα) family and their respective receptors as key players in the glial-neuronal interactive process that regulates LHRH secretion. Our results indicate that TGFα and its distant congener neuregulin (NRG) are produced in hypothalamic astrocytes and stimulate LHRH release indirectly via activation of their respective receptors, located - surprisingly - not on LHRH neurons, but on astrocytes. Activation of EGF receptors by TGFα, and/or the erbB2/erbB4 receptor complex by NRG, leads to glial release of prostaglandin (PG) E2, which then acts directly on LHRH neurons to stimulate LHRH release. That a central blockade of TGFα or NRG action delays puberty, and focal overexpression of TGFα advances it, leads to the conclusion that both TGFα and NRG are physiological components of the central mechanism controlling the initiation of female puberty.
Original language | English (US) |
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Pages (from-to) | 101-106 |
Number of pages | 6 |
Journal | Molecular and Cellular Endocrinology |
Volume | 140 |
Issue number | 1-2 |
DOIs | |
State | Published - May 25 1998 |
Keywords
- Astrocytes
- Cell-cell communication
- Glial cells
- Growth factors
- Hypothalamus
- LHRH neurons
- Sexual development
- Tyrosine kinase receptors
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Endocrinology