Purpose: Subfertility associated with polycystic ovary syndrome (PCOS) mainly originates from oligoovulation/anovulation. Although insulin resistance and androgen excess are known to cause PCOS-associated implantation failure, the consequences of PCOS on endometrial homeostasis and pathophysiology have not been comprehensively understood. In this study, we examined whether the pathophysiologic milieu of PCOS intrinsically affects expression profiles of genes related to insulin signaling and facilitative glucose transporters (GLUTs) in the human endometrium and/or during in vitro decidualization.
Study design: Seven healthy women with regular menstrual cycles and 13 patients with PCOS were recruited for this study. To mimic the hyperandrogenic or hyperinsulinemic milieu in the endometrium of patient with PCOS (PCOSE) in vitro, human endometrial stromal cells (hESCs) were treated with dihydrotestosterone (DHT) or insulin, respectively.
Results: In PCOSE, messenger RNA (mRNA) levels of insulin receptor (IR), IR substrate (IRS) 1, and IRS2 were significantly increased. Furthermore, GLUT1 and GLUT12 were aberrantly increased. Chronic exposure to insulin or DHT aberrantly increased IRS1/IRS2 phosphorylation and protein levels of GLUT1 and GLUT12 in hESCs, suggesting that not only hyperinsulinemic but also hyperandrogenic conditions affect insulin signaling and glucose metabolism. The mRNA microarrays demonstrated that DHT dysregulates various gene sets, including cell cycle and glucose metabolism, in hESCs. Furthermore, DHT suppressed the expression of GLUT1 and GLUT12 as well as decidualization markers, IGFBP1 and prolactin, during in vitro decidualization.
Conclusions: The hyperandrogenic milieu affects gene expression profiles, including gene sets associated with insulin signaling, cell cycle, glucose metabolism, and/or glucose transport, in human endometrium and during in vitro decidualization.
Keywords: androgen; decidualization; endometrium; glucose transporter; polycystic ovary syndrome.