RNA Sequencing of the Androgen-Regulated Transcriptome in Human and Mouse Granulosa Cells

Considering the well-documented importance of androgens in the female reproductive system and particularly in maintenance of the ovarian follicular reserve, follicle growth and granulosa cell proliferation, we hypothesized that activation of the androgen receptor in granulosa cells with DHT induces significant changes in gene transcription. To determine the AR-regulated gene transcriptome in mouse granulosa cells, we treated female mice aged 18 weeks (n=5) with an introperitoneal injection of dihydrotestosterone (DHT, 29 mcg) in a vehicle of 90% sesame oil and 10% ethanol in a total volume of 100 microliters. 18 hours later, granulosa cells were harvested and mRNA was isolated for RNA sequencing. Surprisingly, no genes were differentially expressed in the granulosa cells obtained from DHT-treated compared with vehicle-treated mice. We then assessed the AR-regulated transcriptome in DHT-treated human granulosa-derived KGN cells. After 24 hours of serum starvation, KGN cells were treated with 25 nM DHT or ethanol for 12 hours in five independent experiments, then RNA was extracted for RNA sequencing. In paired analysis to eliminate inter-experimental variability, 173 genes were differentially expressed in DHT-treated compared with vehicle-treated cells. Of these, 125 genes were upregulated by DHT and 48 genes were downregulated by DHT. However, the fold change in expression was very small (ranging from 0.87 to 1.37, DHT vs vehicle). Although these differences were statistically signficant in paired analysis, they are unlikely to be of biological significance due to such small fold changes in expression. We conclude that AR likely has negligible gene-transcription activity in granulosa cells. Importantly, these experiments were not designed to capture any changes in non-coding RNAs.