Extragonadal function of follicle-stimulating hormone: Evidence for a role in endothelial physiology and dysfunction

Aims: Follicle-stimulating hormone (FSH) plays a fundamental role in reproduction stimulating ovarian folliculogenesis, Sertoli cells function and spermatogenesis. However, the recent identification of FSH receptor (FSHR) also in extra-gonadal tissues has suggested that FSH activity may not be limited only to fertility regulation, with conflicting results on the possible role of FSH in endothelial cells. The aim of this study was to investigate FSH role on endothelial function in Human Umbilical Vein Endothelial Cells (HUVECs). Results: Endothelial Nitric oxide synthase (eNOS) expression, eNOS phosphorylation and Nitric Oxide (NO) production resulted increased after the stimulation of HUVEC with recombinant human FSH (rhFSH) at 3.6x103 ng/ml, with increasing Calcium release from intracellular stores. Furthermore, IP3 production increased after rhFSH stimulation despite PTX treatment and NFAT1 was observed prevalently in nucleus. We observed a statistical difference between untreated cells and cells stimulated with 0.36x103 ng/ml and between cells stimulated with 0.36x103 ng/ml and cells stimulated with 1.8x103 ng/ml at 4 and 8 h by Wound healing assay, respectively. Furthermore, a higher cellular permeability was observed in stimulated cells, with atypical VE-cadherin distribution, as well as filamentous actin. Conclusions: Our findings suggest that FSH at high concentrations elicits a signalling that could compromise the endothelial membrane. Indeed, VE-cadherin anomalies may severely affect the endothelial barrier, resulting in an increased membrane permeability. Although NO is an important vasodilatation factor, probably an excessive production could impact on endothelial functionality, partially explaining the increased risk of cardiovascular diseases in menopausal women and men with hypogonadism.