Mammary gland expression of GnRH is mediated by estradiol and progesterone (Lagostomus maximus)

CORSO MC; PROIETTO S; DI GIORGIO NP, LUX-LANTOS V; DORFMAN VB; VITULLO AD; HALPERIN J

Mendoza

Congreso; XL Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2022

Sociedad de Biologia de Cuyo

MAMMARY GLAND EXPRESSION OF GNRH IS MEDIATED BY ESTRADIOL ANDPROGESTERONE (Lagostomus maximus)Corso MC1,2, Proietto S1,2,DiGiorgio N2,3, Lux-Lantos V2,3, Dorfman VB1,2, Vitullo AD1,2, Halperin J1,21Laboratorio de Endocrinología Reproductiva, Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides. CABA, Argentina.2Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)3Instituto de Biología y Medicina Experimental (IBYME)Email: corso.clara@maimonides.eduThe tissue dynamics of the mammary gland (MG) during pregnancy is mainly modulated by prolactin (PRL) and the ovarian steroids estradiol (E2) and progesterone (P4). However, there is a great diversity of local factors that participate in the fine regulation of these processes. In particular, our group determined that the levels of local transcription and translation of gonadotropin-releasing hormone(GnRH) and its receptor (GnRHR) in the MG of adult female vizcachas vary with the stages of the reproductive cycle. Furthermore, by inducing a hyperprolactinemic condition, we have established that MG GnRH content is modulated by PRL. The aim of this work was to further investigate the regulation of mammary GnRH by two approaches: 1) studying the effect of E2 and P4 on the local expression ofthis neuropeptide, and 2) studying the transcriptional factor FoxO3a expression as a potential mediator of GnRH action in MG tissue. To do this, we performed culture experiments on MG explants incubated, on the one hand, with increasing concentrations of E2 or P4, and on the other, with a GnRH analogue. MG-explants cultured with either steroid doubled their GnRH content compared to control explants, which strongly suggests a steroid-dependent regulation of local GnRH. In addition, FoxO3a markedly increased its expression level when MG-explants were stimulated with GnRH, which places this transcription factor downstream of the GnRH signaling pathway in MG tissue. Our results contribute to a better understanding of the role of GnRH in mammary gland tissue remodeling.