Polycystic ovary syndrome: evidence for reduced 3β-hydroxysteroid dehydrogenase gene expression in human luteinizing granulosa cells

In a preview study we found that luteinizing granulosa cells from follicles of patients with polycystic ovary syndrome (PCOS) have a reduced capacity to synthesize progesterone in vitro. Because the 3β -hydroxysteroid dehydrogenase/δ5-δ4-isomerase (3β -HSD) is an important enzyme for the biosynthesis of progesterone, the reduced capacity of PCO luteinizing granulosa cells to synthesize progesterone in vitro may be due to reduced 3β-HSD gene expression. A reverse transcriptase polymerase chain reaction for 3β -HSD was performed and the relative intensity of signals for 3β-HSD was evaluated using computer-assisted densitometry. Cells from polycystic ovaries expressed less 3β -HSD in follicles ≤10 mm (p < 0.05) and in follicles ≥ 16 mm (p < 0.05) than cells from normal ovaries. Furthermore, after human chorionic gonadotropin stimulus (50 ng/ml), cells from polycystic ovaries expressed less 3 β-HSD in follicles ≥ 16 mm (p < 0.01) than cells from normal ovaries. The data show that there is a specific change in the gene expression of 3β-HSD in PCO granulosa cells resulting in a suppressed capacity to secrete progesterone.