Luteinizing hormone receptor, steroidogenesis acute regulatory protein, and steroidogenic enzyme messenger ribonucleic acids are overexpressed in thecal and granulosa cells from polycystic ovaries.

Abstract

Recent data suggest that steroidogenic enzyme messenger ribonucleic acids (mRNAs) may be overexpressed in thecal cells, and LH receptors may be prematurely expressed in granulosa cells in women with polycystic ovaries. The purpose of this study was to determine whether there is abnormal gene expression in thecal and granulosa cells from polycystic ovaries. Ovarian tissue specimens were obtained from 12 women with PCOS and 24 regularly cycling control women. The granulosa cells and the theca interna were microdissected from individual follicles. LH receptor, steroidogenesis acute regulatory protein (StAR), cholesterol side-chain cleavage cytochrome P450 (CYP11A), and 17alpha-hydroxylase/C(17-20) lyase cytochrome P450 (CYP17) mRNAs were measured by RT-PCR. There was no difference between 3- to 7-mm control follicles and dominant follicles with respect to LH receptor mRNA expression in either thecal or granulosa cells. CYP11A and CYP17 mRNAs were higher in thecal cells from 3- to 7-mm follicles than in dominant follicles, but StAR expression was not different. In granulosa cells, StAR and CYP11A mRNA expression was higher in dominant follicles than in 3- to 7-mm follicles. The mean levels of LH receptor, StAR, CYP11A, and CYP17 mRNA expression were higher in thecal cells from PCOS follicles than in size-matched control follicles. In granulosa cells, the mean levels of LH receptor and CYP11A, but not StAR, mRNA expression were higher in PCOS than in control follicles. These data demonstrate that regulatory protein and steroidogenic enzyme mRNAs are overexpressed in thecal and granulosa cells from polycystic ovaries and support the conclusions that the thecal cells are hyperstimulated and the granulosa cells may be prematurely luteinizing.