Transcriptional Regulation of the Estrogen Receptor α Gene by Testosterone in Cultures of Primary Rat Sertoli Cells

Abstract

Background: We wanted to identify the presence of the estrogen receptor (ER) α in Sertoli cells and gain insight on the regulation of the ERα gene expression by testosterone in Sertoli cells. The transcriptional regulation of the ERα gene was investigated in primary Sertoli cell cultures by in situ hybridization and reverse transcription-polymerase chain reaction (RT-PCR). Methods: Primary Sertoli cell culture was performed. The expression levels of ERα and ERβ mRNA in Sertoli cells were detected by Northern blot, RT-PCR, immunocytochemistry and in situ hybridization. Results: The ovary, testis and epididymis showed a moderate to high expression of ERα while the prostate, ovary and LNCap cells showed the ERβ expression. ERα mRNA and protein were detected in the germ cells and Sertoli cells by in situ hybridization and immunocytochemistry. The level of ERα mRNA was gradually decreased in a time-dependent manner after testosterone treatment, and the changes of ERα mRNA were dependent on the concentration of testosterone. Androgen binding protein and testosterone-repressive prostate message-2 (TRPM-2) mRNA were reduced at 24 hour by estradiol, while the transferrin mRNA was not affected. ERα mRNA was strongly detectable in the testes of 7 days-old-rats, but it was gradually decreased from 14 to 21 days of age. The primary Sertoli cells also showed the same pattern. The ERα gene expression was also regulated by testosterone in the Sertoli cells prepared from the 14- and 21-day old rats. Conclusions: These results suggest that ER α is transcriptionally regulated by testosterone and it may play some role in the Sertoli cells. (J Kor Soc Endocrinol 21:106~115, 2006)