Reproductive Regulation of Gene Expression in the Hypothalamic Supraoptic and Paraventricular Nuclei
R A Augustine1, G T Bouwer1, A J Seymour1
1Centre for Neuroendocrinology and Department of Physiology, University of Otago, Dunedin, New Zealand.
Journal of Neuroendocrinology
|December 17, 2015
Summary
Increased prolactin signaling in oxytocin neurons, identified via STAT5 phosphorylation, is crucial for successful reproduction, particularly during birth and lactation in rats. This finding highlights a key mechanism regulating oxytocin secretion.
Area of Science:
- Neuroendocrinology
- Reproductive Biology
- Molecular Biology
Background:
- Oxytocin is vital for reproduction, with increased synthesis and secretion demands during late pregnancy and lactation.
- Magnocellular neurons in the hypothalamic supraoptic and paraventricular nuclei produce oxytocin.
Purpose of the Study:
- To investigate gene expression changes in oxytocin-producing neurons during late pregnancy and lactation.
- To identify genes involved in regulating oxytocin synthesis and secretion.
Main Methods:
- Polymerase chain reaction (PCR) array screening of hypothalamic nuclei (supraoptic and paraventricular) in virgin, late-pregnant, and lactating rats.
- Validation of key gene regulations using real-time quantitative PCR.
- Double-label immunohistochemistry to detect phosphorylated STAT5 in oxytocin neurons.
Main Results:
- Genes encoding suppressors of cytokine signaling, inhibitors of prolactin signaling, were significantly upregulated.
- Phosphorylated signal transducer and activator of transcription 5 (STAT5) was abundant in oxytocin neurons of pregnant and lactating rats, but not virgin rats.
- Prolactin receptor activation influences gene expression through STAT5 phosphorylation.
Conclusions:
- Increased prolactin activation of oxytocin neurons, mediated by STAT5, likely contributes to altered gene expression.
- This mechanism is essential for the physiological changes in oxytocin neurons required for normal birth and lactation.
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