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.
Department of Obstetrics, University of Maryland School of Medicine, Baltimore 21201, USA.
J S
JS
Babischkin
G J
GJ
Pepe
E D
ED
Albrecht
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