Endocrine Abstracts

Follicle stimulating hormone (FSH) is a heterodimeric glycoprotein hormone, crucial for regulating female reproduction. Its actions are mediated through FSHR, a Class A G protein-coupled receptor (GPCR), which primarily couples to Gs/cAMP/PKA pathway to modulate ovarian follicle growth, granulosa cell proliferation, and estrogen production. In addition to dogmatic functions of FSH in reproduction, there is increasing evidence that FSH can act on extragonadal tissues. Specifically, that elevated FSH levels experienced during perimenopause/menopause may directly act on bone, adipose and brain, contributing to increased susceptibility to the development of co-morbidities including osteoporosis, changes in adipose tissue distribution and Alzheimer’s disease, respectively. Inhibiting FSH/FSHR therefore is therapeutically enticing, with potential for a non-steroidal method of contraception and/or preventing the development of menopause-related co-morbidities. The aim of this study therefore was to develop and characterize novel AI generated FSHR inhibitors. 84 small molecule compounds (SMCs) were generated by AI and screened for their ability to inhibit FSH-dependent cre-luciferase activity in HEK 293 cells expressing FSHR. 3 potential inhibitors exhibited over 90% inhibition of FSH-dependent cre-luciferase activity, were taken forward for further analysis. Using the live kinetic Glo sensor cAMP assay, all 3 inhibitors were shown to display concentration-dependent inhibition of FSH-dependent cAMP accumulation, achieving >90% inhibition at 100μM and partial inhibition at 20μM. Interestingly, the inhibitors showed different potencies for inhibiting FSH-dependent ERK phosphorylation, suggesting different functional profiles. Analysis of inhibitor effects on ovarian function suggested little effect of the inhibitors on FSH-dependent ovarian follicle growth, supporting a potential therapeutic role in non-steroidal contraception. Finally, assessment of selectivity to FSHR suggested little cross-reactivity with the related glycoprotein hormone receptor, luteinizing hormone receptor. This study highlights 3 novel FSHR inhibitors that are promising candidates for potential development as therapeutic agents for potential targeting menopause-related co-morbidities and/or non-steroidal contraceptives.