The Pattern of Glucocorticoid and Estrogen Receptors May Explain Differences in Steroid Dependency of Intrauterine Prostaglandin Production at Parturition in Sheep

Abstract

We concluded that the differential effects of cortisol and estradiol on intrauterine PGHS-II expression and PG production may be due to the tissue-specific expression of the GR and ER within the intrauterine tissues. Glucocorticoid effects on trophoblast PG production may be mediated in a positive feed-forward manner. We further suggest that either cortisol or a cortisol-stimulated intermediate, like PGE2, increased P450(C17) expression, leading to a rise in placental estradiol synthesis and triggering maternal intrauterine tissue PG production.

Transcriptomic Profiling of Human Choriodecidua During Term Labor: Inflammation as a Key Driver of Labor

“…Activation of its endogenous inhibitor (NFκB1A/IκB) was also predicted to regulate choriodecidual inflammation; transcription and translation of this gene are stimulated in response to NFκB activation, adding evidence for functionality of this pathway in labor. Fetally derived cortisol, acting via the glucocorticoid receptor (NR3C1), has important roles in driving the labor process in sheep and probably also in human pregnancies . Glucocorticoid receptors are strongly expressed by decidual cells supporting its identification as a putative upstream regulator of decidual chemokine, cytokine, protease, and protease inhibitors .…”

The Ontogeny of Fetal Adrenal Steroidogenesis as a Prerequisite for the Initiation of Parturition

“…Either would be consistent with the failure to detect increases in conjunction with early fetal adrenal activation, and though seemingly important therefore, has not been investigated. Cortisol induced expression of glucocorticoid receptors in the uni-nucleate trophoblast of sheep in late gestation, the same cells that express PGHS-2 [42] . Uni-nucleate trophoblast is also the site of P450c17 expression in the bovine placenta, but P450arom is expressed in multi-nucleate trophoblast [43] .…”

The role of prostaglandins in livestock production

“…Glucorcorticoids not only stimulate fetal tissue differentiation and maturation, but in many species they also initiate parturition by acting in a series of positive feed toward loops to alter placental steroidogenesis (Jenkin and Young, 2004). Glucocorticoids also activate immune and inflammatory pathways, unregulated PGHS-2, attenuate PGDH leading to prostaglandin synthesis and stimulate further glucocorticoid production (Whittle et al, 2006). It is clearly recognized in pregnant animals and women that labour, is associated with an inflammatory response that culminates in release of prostaglandin (Christiaens et al, 2008).…”