Testosterone Impairs Endometrial Receptivity Markers and Trophoblast Spheroid Attachment In Vitro: Reversal by Flutamide in a Model of Polyendocrine Metabolic Ovarian Syndrome

Polyendocrine metabolic ovarian syndrome (PMOS; previously termed polycystic ovary syndrome, PCOS) is a multi-faceted reproductive and endocrinological condition that affects approximately 10% of women of reproductive age. It is typically characterised by chronic anovulation and elevated levels of the androgen testosterone, which have been linked to reduced implantation rates and fertility outcomes. In this study, we investigated whether increased testosterone treatment affected attachment of trophoblast spheroids to an endometrial cell monolayer and the expression of genes known to be involved in the attachment process. Attachment of BeWo spheroids to Ishikawa endometrial cells was significantly reduced when Ishikawa cells were pre-treated for 24 h with pathological and suprapathological doses of testosterone compared to the results for the untreated control, with no significant effect measured following treatment with a physiological testosterone dose (1 nM). Expression of the transcription factor gene HOXA10; integrin β3 (a component of the αVβ3 molecule) and SPP1 (the gene expressing the ligand osteopontin), were significantly decreased in Ishikawa cells following treatment with 10 nM testosterone, along with αVβ3 protein. Treatment with the nonsteroidal antiandrogen flutamide (1 µM) rescued the testosterone-induced decrease in BeWo spheroid–endometrial cell attachment and associated decreases in gene expression. These results suggest that increased levels of testosterone decrease endometrial receptivity and downstream embryo attachment through negatively affecting the expression of genes required for the success of these processes. This testosterone-induced decrease can be reversed in vitro with flutamide treatment. These results highlight the importance of considering endometrial receptivity in the treatment of PMOS-induced infertility.