Expression of the genes for 3 beta-hydroxysteroid dehydrogenase type 1 and cytochrome P450scc during syncytium formation by human placental cytotrophoblast cells in culture and the regulation by progesterone and estradiol

Abstract

We have investigated the expression of cholesterol side-chain cleavage cytochrome P450 (P450scc) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) type 1 genes during human trophoblast differentiation in culture and the modulation of their steady-state mRNA levels by steroids. During the first 24 to 48 h after plating, mononucleated cells aggregated, forming colonies. After 60 h in culture, cell diameters were increased and nuclei appeared centrally distributed within large cells, consistent with syncytiotrophoblast formation. During these striking morphological changes in culture the expression and activity levels of 3 beta-HSD type 1 and P450scc increased significantly as isolated cytotrophoblasts progressed to a differentiated state, with P450scc and 3 beta-HSD type 1 mRNAs activities being more abundant in cells cultured for 48 to 72 h. In the same culture, however, the amount of 3 beta-HSD protein decreased during the first 12 to 24 h by 50% compared with freshly isolated trophoblasts but remained at these levels throughout the culture period. The specific activity of the 3 beta-HSD as determined with pregnenolone or dehydroepiandrosterone was similar but increased with time as syncytiotrophoblast was formed in vitro. These observations provide additional evidence that the expression of these two progesterone-synthesizing enzymes is coincident and that they reach their maximum steady-state mRNA levels at a time when syncytium formation occurs in vitro. Incubation of trophoblast cells with progesterone or estradiol increased the abundance of P450scc and 3 beta-HSD type 1 mRNAs but had no significant effect on the amount of 3 beta-HSD protein. These observations of the regulation of 3 beta-HSD type 1 mRNA levels by steroids suggest a complex relationship of the mechanisms regulating transcription/mRNA processing and transduction of the 3 beta-HSD type 1 gene.

A Unique Co-culture Model for Fundamental and Applied Studies of Human Fetoplacental Steroidogenesis and Interference by Environmental Chemicals

“…For instance, placental β-hCG appears to be involved in the regulation of DHEA sulfation via LH/hCG receptors present in the H295R cells by stimulating sulfotransferases (Rao et al 2004) and could affect availability of androgen precursors for BeWo cells in the co-culture. Moreover, several steroid hormones produced in the placenta, such as estradiol and progesterone, also regulate the expression of the 11β-hydroxysteroid dehydrogenases (HSD11B), which play a role in the regulation of fetal growth and development of the fetal adrenal zone (Beaudoin et al 1997; Kaludjerovic and Ward 2012; Myatt and Sun 2010). The ability of the co-culture to produce mineralo- and glucocorticoids also allows for the study of stress responses and homeostasis.…”

Placental Endocrine Disruption Induced by Cadmium: Effects on P450 Cholesterol Side-Chain Cleavage and 3β-Hydroxysteroid Dehydrogenase Enzymes in Cultured Human Trophoblasts

“…The 3␤-HSD protein may be regulated at both transcriptional and posttranscriptional levels. Similarly, treatment of human trophoblasts with progesterone and estradiol increased 3␤-HSD mRNA levels but had no significant effect on protein levels [40], suggesting that 3␤-HSD steady-state mRNA levels in human placenta could be under posttranscriptional regulation. A similar mechanism has been suggested in respect to FSH-induced gene expression in rat granulosa cells [41].…”

Early Onset Pre-Eclampsia Is Associated with Altered DNA Methylation of Cortisol-Signalling and Steroidogenic Genes in the Placenta

“…While CRH stimulates placental estrogen synthesis ( CYP19 expression) [14], its repressive effect on progesterone synthesis ( CYP11A1 and HSD3B1 expression) [66] may be dampened in the pre-eclampsia-associated placenta. Maternal progesterone, but not estrogen, concentrations are increased in women with preeclampsia [93], [94] and both steroid hormones positively stimulate CYP11A1 and HSD3B1 expression in trophoblast cells [95]. Therefore elevated progesterone, despite elevated CRH, may act in a compensatory feed-forward loop to promote placental steroidogenesis.…”