Developmental expression of placental trophoblast P-450 cholesterol side-chain cleavage, adrenodoxin and delta 5-3 beta-hydroxysteroid dehydrogenase/isomerase messenger ribonucleic acids during baboon pregnancy.
The present study determined whether the elevation in oestrogen, which occurs with advancing baboon pregnancy, is associated with a developmental increase in expression of the placental enzymes catalysing progesterone synthesis. The mRNA levels for P-450 cholesterol side-chain cleavage (P-450scc), adrenodoxin, and delta 5-3 beta-hydroxysteroid dehydrogenase/isomerase (3 beta-HSD) were assessed by Northern blot analysis in placental syncytiotrophoblasts isolated from baboons in early (days 58-65), mid- (days 97-113) and late (days 161-175), gestation (term = 184 days). Placental villous tissue was dispersed and subjected to 50 per cent Percoll density gradient centrifugation to obtain primarily syncytiotrophoblasts. Mean (+/- S.E.) P-450scc mRNA level, expressed as a ratio of beta-actin in the syncytiotrophoblast-rich fraction, progressively increased with advancing pregnancy to a level in late gestation (1.81 +/- 0.28 arbitrary units) that was approximately sixfold (P < 0.01) greater than in early gestation (0.31 +/- 0.08) and approximately twofold greater (P < 0.05) than in mid-gestation (0.97 +/- 0.24). In contrast adrenodoxin mRNA expression was similar at early (0.97), mid- (1.14 +/- 0.12) and late (1.16 +/- 0.13) gestation. Syncytiotrophoblast 3 beta-HSD mRNA levels also remained constant in early (1.69), mid- (1.89 +/- 0.41) and late (1.34 +/- 0.41) gestation. On the basis of these findings, we propose that villous syncytiotrophoblasts undergo functional/biochemical differentiation, resulting in a coordinated upregulation of specific components of the steroid biosynthetic pathway required for progesterone biosynthesis during the course of primate pregnancy.
Babischkin
J S
JS
Department of Obstetrics, University of Maryland School of Medicine, Baltimore 21201, USA.
Pepe
G J
GJ
Albrecht
E D
ED
D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics*; D000325:Adrenodoxin / Q000235:genetics*; D000818:Animals; D015152:Blotting, Northern; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D009929:Organ Size; D010215:Papio; D010920:Placenta / Q000033:anatomy & histology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014327:Trophoblasts / Q000201:enzymology*
D012333:RNA, Messenger; D000325:Adrenodoxin; D015096:3-Hydroxysteroid Dehydrogenases; C031954:delta(5)-3 beta-hydroxysteroid dehydrogenase; D002786:Cholesterol Side-Chain Cleavage Enzyme