Identification of differentially expressed proteins in the ovaries of menopausal women.

ABSTRACT

PURPOSE: This study investigated proteins differentially expressed in the ovaries of menopausal women in comparison to childbearing women. METHODS: Differential protein expression was screened by difference gel electrophoresis and 2-D SDS-PAGE. Four differentially expressed proteins were excised manually, identified by mass spectrometry and confirmed by immunoblot and immunohistochemistry. RESULTS: The four proteins were identified as serum amyloid P, heat shock protein 27, Glyoxalase I and Ubiquitin carboxy-terminal hydrolase. Serum amyloid P expression was significantly up-regulated in the ovaries of menopausal women by immunoblot analysis (p < 0.05), Glyoxalase I and Ubiquitin carboxy-terminal hydrolase displayed an altered expression pattern, with higher expression in the atretic follicles of menopausal women. Weak Glyoxalase I and Ubiquitin carboxy-terminal hydrolase were observed in the granulosa and theca cells of the follicles of childbearing women. Heat shock protein 27 and serum amyloid P were clearly observed in the atretic follicles of menopausal women, while their expression was restricted to the theca cells and cytoplasm of primordial follicles in the ovaries of childbearing women. All four proteins were predominantly expressed in the atretic follicles of menopausal women. CONCLUSIONS: These data suggest that the identified proteins may play a role in the regulation of follicle atresia in menopausal women, although their functions and mechanism warrant further investigation.