Regulating Integrin β1 to Restore Gonadotropin-Releasing Hormone-Tanycyte Unit Function in Polycystic Ovary Syndrome-Related Hypothalamic Dysregulation.

Abstract

Excessive gonadotropin-releasing hormone (GnRH) is considered to be an initiating factor in the etiology of polycystic ovary syndrome (PCOS). GnRH neuronal axons terminate at the hypothalamic arcuate nucleus and median eminence, where tanycytes, specialized glial cells, have been proposed to modulate GnRH secretion through plasticity. However, the precise role of the "GnRH-tanycyte unit" during the pathological state of PCOS has not been thoroughly explored. In this study, we demonstrated the architecture and distribution of GnRH neurons and tanycytes. In PCOS-like mice, retracted tanycyte processes and dysregulated GnRH-tanycyte unit may create an environment conducive to the excessive secretion of GnRH and subsequent reproductive endocrine dysfunction. Mechanistically, excessive androgens impair hypothalamic neuroglial homeostasis by acting through the androgen receptor (AR) and its downstream target integrin β1 (Itgb1), thereby suppressing the FAK/TGF-βR1/Smad2 signaling pathway. Both selective deletion of AR and overexpression of Itgb1 in tanycytes counteracted the detrimental effects of androgens, alleviating endocrine dysfunction. Collectively, this study highlights the alterations in the GnRH-tanycyte unit mediated by androgen/AR/Itgb1 signaling and provides a novel perspective for developing therapies for hypothalamic hormone secretion disorders by maintaining solid neuroglial structures in the brain.