This Article Full Text Full Text (PDF) All Versions of this Article: 91/6/2239    most recent Author Manuscript (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nair, A. K. Articles by Menon, K. M. J. Search for Related Content PubMed PubMed Citation Articles by Nair, A. K. Articles by Menon, K. M. J. Related Collections Female Endocrinology

The Role of Luteinizing Hormone/Human Chorionic Gonadotropin Receptor-Specific mRNA Binding Protein in Regulating Receptor Expression in Human Ovarian Granulosa Cells

Departments of Obstetrics/Gynecology and Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0617

Address all correspondence and requests for reprints to: Dr. K. M. J. Menon, 6428 Medical Science 1, 1301 East Catherine Street, Ann Arbor, Michigan 48109-0617.

Context: In normally cycling women, LH receptor mRNA expression undergoes transient down-regulation after the LH surge. The same phenomenon is also seen during a hormonally induced ovarian cycle where the LH receptor mRNA expression is down-regulated in response to the administration of human chorionic gonadotropin (hCG). Although the granulosa cells isolated from the follicular aspirates at this stage show a decline in the expression of LH receptor mRNA, this diminished receptor expression returns to control levels upon culturing in serum-containing medium.

Objective: To understand the mechanism of hCG-induced loss of LH receptor mRNA expression, a cytosolic fraction (S100) was isolated from the granulosa cells, and its ability to bind LH receptor mRNA was assayed by performing RNA electrophoretic mobility gel shift analysis.

Results: The results showed that the mRNA binding activity of the S100 fraction was induced in the freshly isolated granulosa cells (d 1) from the follicular aspirates collected from women who had been injected with hCG to induce ovulation. The LH receptor mRNA expression in granulosa cells on d 1, as assessed by real-time PCR and Northern blot analysis, was significantly suppressed. Both the expression of LH receptor mRNA and RNA binding activity in the S100 fraction were then assessed after culturing granulosa cells for 4 d. The results showed that the LH receptor mRNA expression was significantly higher on d 4 compared with that seen on d 1. However, the RNA binding activity of the S100 fraction was significantly decreased on d 4 compared with that seen on d 1. These results show an increased association of RNA binding protein during LH receptor mRNA down-regulation.

Conclusion: The present results support the notion that LH receptor mRNA expression in the human ovaries is regulated by an RNA binding protein.

This article has been cited by other articles:

				L. Wang, A. K. Nair, and K. M. J. Menon Ribonucleic Acid Binding Protein-Mediated Regulation of Luteinizing Hormone Receptor Expression in Granulosa Cells: Relationship to Sterol Metabolism Mol. Endocrinol., September 1, 2007; 21(9): 2233 - 2241. [Abstract] [Full Text] [PDF]