MOLECULAR MARKERS ASSOCIATED TO THE MAINTENANCE OF THE GERMINAL RESERVE IN INFANT AND ADOLESCENT HUMAN OVARY

CALABRO, LARA; ALBAMONTE, MIRTA; ZUCCARDI, LUIS; STELLA, INES; HALPERIN, JULIA; ALFREDO DANIEL VITULLO; ALBAMONTE, MARIA ITATI

Ciudad Autonoma de Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

SAIC, SAIB, SAA, SAI, SAB, SAB, SAFE, SAFIS, SAH y SAP

During fetal human ovary development, 7 millions of oogonia originateat mid-gestation; most of them are lost before birth and evenbefore reaching puberty. Fertile period in woman requires the preservationand a moderate use of the remaining primordial and primaryfollicles ovarian reserve. Follicular development initiates whensome follicles from the ovarian reserve are recruited into a growingpool. The continuous recruitment into the growing pool, controlledby intra-ovarian stimulatory and inhibitory factors both in oocytes (O)and granulosa cells (GC), leads to the decrease of the ovarian reserve.Mechanisms involved are not yet completely enveiled, especiallyin the infant-adolescent period. FOXO3 and PTEN are factorsinvolved in the PI3K-Akt signaling pathway apparently associated topreserve follicles in a dormant state. Foxo3 protein is a transcriptionalfactor which is exported to the cytoplasm upon phosphorylationwhen follicles are recruited from the reserve in mice. PTEN proteinacts inhibiting FOXO3 phosphorylation indirectly. In this study, theexpression pattern of FOXO3, pFOXO3 and PTEN was analyzed byimmunohistochemistry and western blot (WB) in human infant-adolescentovaries (n=12) from 9 to 19 years old. FOXO3 was detectedin O nuclei in primordial, primary, secondary, antral follicles andcorpus luteum (CL). pFOXO3 was found in O cytoplasm of someprimordial and primary follicles. PTEN expressed in CL and GC fromsome antral and atretic follicles and it was also slightly detected in Ocytoplasm in a few primordial follicles. As far as we could track in theliterature, this is the first description of FOXO3/pFOXO3/PTEN markersin the infant-adolescent ovary. The spatio-temporal expressionpattern of these markers suggest a synchronized balance which favorscell cycle arrest, apoptosis and inhibition of follicular growth.Keywords: ovarian reserve, follicle recruitment, infant-adolescentovary.