Insight on the intracrinology of menopause: androgen production within the human vagina

In this study, we investigated steroidogenic gene mRNA expression in human vaginas and verified the ability of human vagina smooth muscle cells (hvSMCs) to synthesize androgens from upstream precursor dehydroepiandrosterone (DHEA). As a readout for androgen receptor (AR) activation, we evaluated the mRNA expression of various androgen-dependent markers.hvSMCs were isolated from vagina tissues of women undergoing surgery for benign gynecological diseases. In these cells, we evaluated mRNA expression of several steroidogenic enzymes and sex steroid receptors using real time RT-PCR. Androgen production was quantified with liquid chromatography tandem-mass spectrometry (LC-MS/MS).In vaginal tissues, AR mRNA was significantly less expressed than estrogen receptor α (ERα), whereas in hvSMCs, its mRNA expression was higher than progestin and both estrogen receptors. In hvSMCs and in vaginal tissue, when compared to ovaries, the mRNA expression of pro-androgenic steroidogenic enzymes (HSD3β1/β2, HSD17β3/β5), along with 5α-reductase isoforms and sulfo-transferase, resulted as being more abundant. In addition, enzymes involved in androgen inactivation were less expressed than in the ovaries. The LC-MS/MS analysis revealed that, in hvSMCs, short term DHEA supplementation increased Δ4-androstenedione levels in spent medium, while increasing testosterone (T) and dihydrotestosterone (DHT) secretion after longer incubation. Finally, androgenic signaling activation was evaluated through AR-dependent marker mRNA expression, after DHEA and T stimulation. This study confirmed that the human vagina is an androgen-target organ with the ability to synthesize androgens, thus providing support for the use of androgens for local symptoms of genito-urinary syndrome in menopause.